Volume II Contents
Perioperative Care
Part I
001
Part II
019
Part III
030
Part IV
043
Problems in Related Specialties
057
Skin and Soft Tissue
075
Surgical Critical Care
Part I
089
Part II
102
Trauma
Part I
112
Part II
129
Vascular
143
Perioperative Care Part I
rhabdomyolysis.
The
modestly
elevated
sodium
concentration and the urine specific gravity suggest at least a
moderate degree of dehydration. Hypokalemia is evident in
this case and may be even lower after rehydration.
ITEMS 1-30
For each question, select the best possible response.
1. A 19-year-old, black military recruit complains of severe
pain in his legs the morning after a 5-mile march in full
combat gear during mid-August at a southern basic training
camp. He has no history of similar episodes and no reported
previous heat-related injury. He has no history of sickle cell
disease. He is awake, conversant, and oriented with normal
vital signs. Other than severe discomfort in his calves and
thighs, his physical examination is negative. Laboratory
studies demonstrate the following:
Serum
Urine
Na+ = 147 mEq/L (136-145 mEq/L)
K+ = 2.8 mEq/L (3.5 5.0 mEq/L)
Cl- 101 mEq/L (95-105 mEq/L)
CO2 = 28 mEq/L (23 29 mEq/L)
BUN = 17 mg/dL (7-20 mEq/L)
Glucose = 80 mg/dL (70-100
mEq/L)
Creatinine = 1.1 mg/dL (0.4-1.3
mEq/L)
Serum Ca++ = 8.2 mg/dL (8.5-10.2
mEq/L)
Creatine phosphokinase = 400 U/L
(60-174 U/L)
Mg++ = 2 mg/dL (1.5-2.5 mEq/L)
Initial treatment should consist of
containing
A.
B.
C.
D.
E.
Numerous studies have demonstrated that serum potassium
concentrations rise markedly during extreme exercise but fall
to concentrations well below baseline values, even at 5minutes after cessation of the activity and remain below
baseline for as much as several hours. The rise and fall of
serum potassium is directly proportional to the bulk of the
muscle mass used during exercise. This finding is not
surprising, because muscle contains the largest body pool of
this ion. The fall in potassium after exertion is thought to be
due to catecholamine activation of Na+/K+-ATPase, which
serves to drive potassium into cells. It could be anticipated
that measured serum potassium would be even lower if
intravascular volume were restored to baseline levels. Thus,
rehydration should be supplemented with potassium. The
clinical significance of this strategy lies in the fact that
hypokalemia in presumably healthy individuals is linked to
cardiac rhythm disturbances in patients with chronic
conditions and possibly to sudden death after extreme
exertion.
Color: dark yellow
pH: 5.7
Specific gravity: 1.038
Dip Stick
Blood: trace
Glucose: negative
Protein: trace
Microscopic: crystals
present, few white
blood cells, no red
blood cells or casts
intravenous fluids
Magnesium replacement may be necessary if serum values
of potassium do not respond to potassium supplementation or
if serum magnesium levels are low. Renal excretion of
potassium is not reversed in the absence of adequate levels of
magnesium. The addition of glucose may stimulate insulin
secretion, driving potassium intracellularly and further
lowering serum potassium concentration. Bicarbonate has
been used, on a theoretical basis, to increase the solubility of
myoglobin in rhabdomyolysis by increasing urinary pH,
along with mannitol to increase urine flow. Few data exist to
support this practice. There is no compelling evidence in this
case that rhabdomyolysis is present or at least not to the
degree that would be of concern for the development of renal
failure. There is nothing to suggest that calcium
supplementation is required.
magnesium.
calcium.
glucose.
potassium.
bicarbonate.
Answer:
D
Rhabdomyolysis is obviously a concern in this recruit after
extreme exertion during training on a presumably hot August
day. Exertional rhabdomyolysis is frequently seen in military
recruits unaccustomed to vigorous exercise, particularly
blacks, individuals with sickle cell disease, and those with a
history of heart-related injury. However, sufficient
information is available to exclude the diagnosis of
rhabdomyolysis: serum creatinine kinase (creatinine
phosphokinase) is not elevated to the extent seen with
rhabdomyolysis, usually 10-fold the upper limit of normal.
Urine myoglobin levels rise quickly with rhabdomyolysis but
are rapidly cleared by renal excretion, remaining elevated for
only 2 to 12 hours after injury. Myoglobinuria is suggested
by the urine dipstick being positive for "trace" blood without
red blood cells being identified by urine microscopy. Serum
creatinine kinase levels remain elevated for several days,
making it a more reliable test. Further, serum potassium
levels would be expected to be markedly elevated with
2. The patient shown in figure 2.1 was recently seen by his
primary physician and started on an angiotensin converting
enzyme (ACE) inhibitor. Which of the following statements
about this condition is true?
A. It has no effect on the gastrointestinal tract.
B. This reaction is unlikely to recur with repeat exposure of
the inciting drug.
C. Potential airway compromise prompts aggressive early
intervention.
D. Black patients uncommonly manifest this condition
compared with patients of European descent.
E. Treatment is diuretics and steroids.
Answer:
1
C
Angiotensin converting enzyme (ACE) inhibitors can
interfere with pathways to dear kinins and other vasoactive
peptides, leading to angioedema. Angioedema commonly
affects the lips, tongue, or face, but it can also involve the
bowel, leading to presentation with abdominal pain or
obstruction. Rechallenge with the offending drug typically
leads to recurrence of the angioedema. Black patients have a
5-fold higher incidence of this condition over white patients.
Diuretics and steroids are not a part of the management of
ACE inhibitor associated angioedema. The treatment is
discontinuation of the drug and airway management. Early
intubation with surgical backup for emergency surgical
airway is indicated when this disease is encountered.
4. Which of the following statements is true regarding
postoperative fluid management?
A. Intravenous fluids should be administered to maintain a
urine output of mL/kg/hour.
B. Urine output of less than 0.5 mL/kg/hour is associated
with increased hospital stay.
C. Decreased urine output is a physiologic response to
surgical stress.
D. Fluid overload reduces postoperative morbidity.
E. Enhanced recovery after surgery pathways improve
outcomes by fluid loading.
Answer:
3. A 45-year-old man is involved in a motor vehicle crash
and is admitted to your service for multiple lower extremity
fractures. Which of the following statements regarding
venous thromboembolism (VTE) is true for this patient?
What has traditionally been considered oliguria secondary to
postoperative hypovolemia was recently recognized as a
normal physiologic response to surgical stress. Fluids
administered to achieve a urine output of 1 mL/kg/hour
exceed even the classic goal of 0.5 mL/kg/hour. In a
randomized trial of patients undergoing major abdominal
surgery, a urine output goal of 0.2 mL/kg/hour was not
associated with any injury to the kidney and did not affect
length of stay. In a trial of enhanced recovery care in more
than 1900 patients, fluid overloading was a strong predictor
of later complications. Finally, a review of enhanced recovery
pathways revealed that improved outcomes are achieved by
fluid-restrictive strategies.
A. Low molecular weight heparin (LMWH) prophylaxis is
preferred over unfractionated heparin.
B. VTE are rare in the first few days of hospitalization.
C. Chemical VTE prophylaxis should be withheld between
12 and 24 hours before open reduction and internal
fixation.
D. Rates of deep vein thrombosis are not influenced by
surveillance bias.
E. Titrating the dose of LMWH with thromboelastography
decreases VTE rates.
Answer:
C
5. A 29-year-old woman is 19 weeks pregnant and presents
with a changing mole on her leg. Biopsy shows a 1.5-mm
Breslow depth, nonulcerated melanoma. Examination reveals
a gravid uterus and no groin adenopathy. Wide local excision
and sentinel node biopsy are planned. The patient should be
told that
A
Venous thromboembolism (VTE) has persisted despite
aggressive monitoring and prophylaxis by physicians and
healthcare systems. Several studies are under way to examine
the addition of aspirin to low molecular weight heparin
(LMWH) or replacement of LMWH with aspirin for VTE
prophylaxis. Meanwhile, a review of data from the Michigan
Trauma Quality Improvement Program system suggested that
LMWH was associated with reduced mortality and VTE
compared with unfractionated heparin. This and another
study showed a preponderance of VTE in the first few days
of hospitalization.
A. surgery should be done under spinal anesthetic.
B. radioactive tracers for the sentinel node biopsy are
contraindicated.
C. operation should be delayed until the third trimester.
D. the prognosis of melanoma is not affected by pregnancy.
E. preoperative CT scanning is indicated.
A randomized trial of thromboelastography-guided versus
fixed-dose LMWH showed no effect on VTE rates. Chest
guidelines for VTE prophylaxis in orthopedic surgery
recommended starting preoperative chemical prophylaxis
between 12 and 24 hours before surgery. Although VTE has
been described by the US government as a "never event,"
VTEs do still occur despite prophylaxis. Due to surveillance
bias, deep vein thrombosis rate after the implementation of
routine duplex surveillance of high-risk patients is
significantly higher than before surveillance—"seek and you
shall find."
Answer:
D
Approximately one-third of women with melanoma are of
childbearing age, and melanoma is the most common
malignancy encountered during pregnancy. Traditionally,
pregnancy-associated melanoma (PAM) was thought to be
associated with a worse prognosis. More recent studies show
no significant differences in stage at presentation; recurrence
rates; or disease-free, melanoma specific, or overall survival
rates between PAM and non-PAM patients. The feared event
of transplacental transfer of melanoma to the fetus is rare; no
2
cases of this were found in recent reports totaling 171 PAM
patients.
Acid-base disturbances among critically ill patients are some
of the most common problems encountered in the intensive
care unit. Understanding the nuances of add base aberrations
is complicated by a history of confusing terminology,
concepts that are counterintuitive, and a persistent
controversy over the physio-physical-chemical mechanisms
that account for the abnormalities encountered.
Understanding is further complicated by differences in the
buffering capacity of the 3 different bodily fluid
compartments (i.e., the intravascular, extravascular, and
intracellular spaces). Currently, 3 methods are used to
quantify the deviations from the physiological pH at which
human cells function with maximum efficiency. Careful
analysis of each of these methods demonstrates that although
they have a different focus, they are generally
complementary.
Rather, survival in PAM patients is dependent on the same
factors as non-PAM patients: Breslow thickness, tumor
ulceration, and sentinel node status. Accordingly, PAM
patients should be treated in the same fashion as non-PAM
patients, with expeditious wide excision and sentinel lymph
node biopsy. In a recent review of 15 PAM patients
undergoing sentinel lymph node biopsy, all had general
anesthesia, the mean gestation age at operation was 20 weeks,
and all but one had injection of radioactive tracer for lymph
node mapping. 99mTc sulfur colloid is safe for the fetus if the
dose is kept below 50 mGy, and lymphoscintigraphy delivers
less than 5 mGy to the fetus. Conversely, blue dye is often not
used because of the potential teratogenic and anaphylactic
risks.
The first and most commonly used approach, the "traditional
approach," is based on the Henderson-Hasselbalch equation,
developed in 1916 by Henderson and modified some 8 years
later by Hasselbalch, who added the logarithmic expression
of the ionization of carbonic add in an aqueous solution.
This patient has clinical stage T2aN0, IB melanoma;
regardless of pregnancy, preoperative CT scanning is not
indicated by accepted guidelines. Scans should be done
postoperatively if the operation upstages the patient, by which
time she may be postpartum and scanning would therefore be
safer.
H+ x HCO3- ↔ H2CO3 ↔ CO2 x H2O
Henderson Equation:
H+ x HCO3- = pKa x CO2 x H2O
Henderson-Hasselbalch Equation:
pH = pKa + logl0 (HCO3/O.03 x CO2)
6. A 24-year-old man sustained multiple injuries (injury
severity score = 34) as the result of a motor vehicle crash 2
weeks ago. He developed acute respiratory distress syndrome
requiring mechanical ventilation. He is being treated for
sepsis and appears to be improving, as indicated by
normalization of vital signs with removal of pressers,
improved urine output, less requirement far ventilator
support, and a reduction in his leukocytosis. Current
laboratory values are as follows:
Where k and pKa are the dissociation constants of carbonic
add and 0.3 represents the solubility of CO2 in plasma.
Use of the Henderson-Hasselbalch approach presumes that
bicarbonate and carbon dioxide are independent variables
with respect to pH, the dependent variable. Fortunately, this
approach is simple. Results for the bicarbonate are calculated
by modem blood gas analyzers readily available, accurate,
and appropriate for most of the simple, direct add-base
abnormalities. A change in the PaCO2 of 12 mm Hg can be
expected to produce a pH gain or loss of 0.1; gain if the
PaCO2 increases (respiratory acidosis) and loss if the PaCO2
decreases (respiratory alkalosis). Further, a change in pH of
0.1 equates to a change in bicarbonate of approximately 6
mEq/L (i.e., if the pH is 7.5, this represents a gain of 6 mEq/L
of HCO3-, and loss of the same amount if the pH is 7.3,
assuming a normal pH of 7.4). Changes in ventilation produce
nearly immediate effects, whereas renal compensation for the
change requires days. Compensation is never complete,
returning pH to the physiological normal value of 7.4. As an
example, a respiratory acidosis with a PaCO2 of 52 mm Hg
and a measured pH of 7.35 represents a partial compensation
by an increase in HCO3-
Serum
Arterial Blood Gases
Na+ = 131 mEq/L (136-145 mEq/L)
PaO2 = 98 mm Hg
K+ = 4.2 mEq/L (3.5-5.0 mEq/L)
PaCO2 = 41 mm Hg
Cl- = 86 mEq/L (95-105 mEq/L)
pH = 7.32
BUN = 8 mg/dL (7-20 mEq/L)
Sat = 99%
Albumin = 0.8 g/dL (3.5-5.2 g/dL)
Base excess = -4.8 mEq/L
Creatinine = 1.0 mg/dL (0.4-1.3 mEq/L)
Serum Ca++ = 3.6 mg/dL (8.5-10.2
mEq/L)
Mg++ = 2.2 mg/dL (1.5-2.5 mEq/L)
HCO3- = 21 mEq/L (calculated; 20-29
mEq)
PO4 = 2.3 mg/dL (2.5-4.5 mg/dL)
The underlying acid-base aberration is best described as a
A.
B.
C.
D.
E.
severe metabolic acidosis.
mixed respiratory-metabolic acidosis.
uncompensated respiratory acidosis.
partially compensated respiratory acidosis.
metabolic alkalosis and respiratory acidosis.
Answer:
The management of acid-base changes was further refined by
the use of the concept of base excess, introduced by SieggardAndersen and named the van Slykes equation,
acknowledging his contributions to the understanding of addbase physiology:
A
3
BE = 0.02786 x PaCO2 x 10(pH-6.1) + (13.77 x pH) -124.58
[Cl-] = 92 mEq/L
SID = HCO3 +Alb-+ Pi-
This value is also provided by blood gas machines, obviating
the need for calculation at the bedside. Some confusion,
however, is introduced by the concept of a "negative" base
excess, which implies an "acidosis." Simultaneous
calculation of the anion gap may also shed light on an addbase relationship. Because all anions cannot be measured
readily, there is always a calculated anion gap, normally 6 to
12 mEq/L. The anion gap can be expressed as follows:
Alb- = Alb g/L x (0.123 x pH - 0.631) (in g/L)
Alb- = 8 x (0.123 x 7.32 - 0.631)
Alb- = 6.58 g/L
Note the units used in the formula. 0.8 g/dL = 8.0 g/L
Pi- = Pi x (0.309 x pH - 0.469) (in mmol/L)
Pi- = 2.3 x (0.309 x pH - 0.469)
Pi- =4.87
therefore
SID = 21+ 6.58+ 4.87
SID = 32.45 mmol/L
AG = Na++ K+- Cl—HCO3
AG-131 +4.2-86-21
AG = 28.2 mEq/L
A high anion gap implies a metabolic acidosis. A low anion
gap is rare and is the result of abnormal serum proteins (e.g.,
myeloma, monoclonal gammopathies). In reality, there can
never be a true anion gap based on the principle of electrical
neutrality: the sum of all anions and equal to the sum of all
cations. As such, a high anion gap implies the presence of an
unmeasured anion, such as in methanol ingestion, uremia,
diabetic ketoacidosis, propylene glycol, isoniazid
intoxication,
lactate,
ethylene
glycol
ingestion,
rhabdomyolysis, or salicylates, "MUD PILERS" the
mnemonic memorized by most medical students.
These values indicate that the metabolic acidosis seen in this
patient is worse than suggested by the pH alone and the
negative base excess: the decrease in the SID from the normal
value of 40 based on plasma water excess, the increase in the
corrected anion gap based on severe hypoalbuminemia, and
the increase in Pi compound the acidosis. This is modified to
some degree by the chloride deficit and the severe
hypoalbuminemia, both of which serve to have an
alkalinizing effect on the pH. There is no respiratory acidosis
or alkalosis.
In the 1980s, Peter Stewart proposed a third approach to the
evaluation of acid-base physiology. Stewart's approach,
lauded by many and criticized by an equal number, focuses
on the physical-chemical aspects of electrical neutrality. In
this analysis, H4 (and consequentially pH) and HCO3- are
dependent variables, and their change is the result of a change
in the strong ion difference (SID) that considers the rote of
nonvolatile weak acids, such as albumin and inorganic
phosphate (Pi), and the impact of chloride. Stewart's method
requires the simultaneous calculation of 6 different equations,
a process that until the development of computer algorithms,
and now smart phone apps, made this approach too
cumbersome for bedside use. Perhaps the most important
lessons for the clinician from this approach include the impact
of (1) volume expansion/contraction as reflected in the serum
sodium;(2) serum albumin [Alb] inorganic phosphate (Pi),
when added to HCO3- constitute the SID (normal value 40);
(3) water itself is the largest reservoir of H+ in the body,(4)
strong unidentified anions cannot be measured but can be
calculated; and (5) measured values of chloride, albumin, and
phosphate must be mathematically corrected based on the
water excess or deficit.
The implications for management of the acid-base
abnormality, highlighted by this more complicated but more
insightful analysis, could be inferred by the recognition of the
volume
excess
(i.e.,
sodium),
the
profound
hypoalbuminemia, and the corrected anion gap. Intravenous
volume restriction in addition to measures to improve the
patient’s nutritional status are indicated. As some authors
have concluded, older, more familiar tools to analyze acidbase abnormalities allow the clinician to arrive at the same
conclusions as the more complicated methods.
7. A 67-year-old man has a partial bowel obstruction and
undergoes a colonoscopy that shows a fungating lesion in his
sigmoid colon. In the recovery room; he has chest pain and
has ST segment elevation on his electrocardiogram. Coronary
angiogram is performed and shows severe left anterior
descending stenosis; Which intervention would allow
sigmoid colectomy to be performed in the next 2 weeks with
minimal bleeding and thrombosis risk?
A.
B.
C.
D.
E.
Values for the patient presented are as follows:
AG adjusted = AG measure + 0.25(Alb normal - Alb measured) (in
mEq/L)
AG adj = 28.2 + 0.25(45 - 8)
AG adj = 37.5 mEq/L
Cl-corr = Cl-measured x Na+normal /Na+measured (in mEq/L)
Cl-corr = 86 x 140/131 = 86 x 1.068
Placement of a bare metal stent
Placement of a drug-eluting stent
Angioplasty of the left anterior descending lesion
Coronary artery bypass grafting
Continuous unfractionated heparin intravenously for 3
weeks
Answer:
4
C
In a patient with significant coronary disease who also needs
urgent noncardiac surgery, the question is which
revascularization strategy is best. A coronary artery bypass
(CABG) will usually have significant long-term durability
but is associated with a 5% in hospital mortality if performed
in the setting of an acute coronary event. Angioplasty without
a stent would allow the earliest intervention for the colon
lesion, because there is no stent in place to thrombose if the
antiplatelet drugs are stopped. Discontinuation of antiplatelet
therapy after stent placement puts the patient at risk for early
stent thrombosis. The earlier the discontinuation of
antiplatelet therapy occurs, the greater the risk. Although
initial studies showed that antiplatelet agents could be
stopped sooner after bare metal stent implantation, more
recent studies suggest that stent-related thrombotic
complications occur for approximately 6 months, regardless
of the type of stent. Administering 3 weeks of unfractionated
heparin without addressing the underlying anatomical disease
(left anterior descending coronary artery stenosis) will not
impact the patient's subsequent cardiac risk from the
noncardiac procedure.
sodium, chloride, and magnesium, may accompany
potassium losses through the gastrointestinal tract. In cases of
hypokalemia refractory to potassium supplementation,
magnesium needs to be replaced concomitantly. Magnesium
is the most common divalent cation in human cells, and
magnesium deficiency impairs the Na/K-ATPase pump,
leading to renal potassium wasting. Supplemental citrate and
phosphate have no effect on potassium, and the
administration of glucose and insulin would only drive
potassium into the cell. Ammonium chloride, occasionally
used to correct metabolic alkalosis, does not assist in the
retention of potassium.
9. An otherwise healthy 52-year-old woman underwent an
uneventful right hemicolectomy and ileocolostomy for an
angiodysplastic lesion in her cecum. An ileus and her
inability to take oral nourishment has kept her hospitalized.
Postoperatively, she was given unfractionated heparin for
deep vein thrombosis prophylaxis. On postoperative day 6,
her platelet count was 30,000/mm3 (baseline 230,000/mm3).
Heparin was discontinued and an anti-PF4/Heparin-ELISA
was requested, which was positive (OD 1.5). After a flush of
a central venous line with heparin solution an hour later, the
patient developed cyanosis of the nail beds of both hands
despite palpable radial artery pulses. The most appropriate
management at this point is
8. A 28-year-old woman with longstanding inflammatory
bowel disease underwent an urgent total abdominal
colectomy for toxic megacolon after 10 days of intractable
diarrhea. Postoperatively, she was found to be hypokalemic
(potassium = 2.2 mEq/L; 3.5-5.0 mEq/L) and was begun on
intravenous potassium chloride. Her blood glucose is 170
mg/dL (70-100 mg/dL). After 24 hours of replacement, her
potassium is only 2.4 mEq/L (13.5-5.0 mEq/L). In addition to
continued potassium chloride administration, successful
correction of her potassium deficit will likely require the
infusion of
A.
B.
C.
D.
E.
A.
B.
C.
D.
E.
citrate.
phosphate.
magnesium.
insulin and glucose.
ammonium chloride.
Answer:
platelet transfusion.
streptokinase.
warfarin.
argatroban.
enoxaparin.
Answer:
D
Thrombocytopenia is common in intensive care unit patients.
Approximately 50% of intensive care unit patients have
platelet counts less than 150,000/mm3 (150,000400,000/mm3), and 10% will have counts less than
50,000/mm3. Humans produce approximately 150 billion
platelets/day with an average lifespan of 10 days. Causes of
reduced platelets include (1) hemodilution from resuscitation
with intravenous fluids; (2) sequestration from
hepatosplenomegaly; (3) consumption from blood loss or
sepsis/systemic inflammatory response syndrome; (4)
underproduction due to viral illness, drugs, and other toxins;
and (5) destruction by immune complexes from heparininduced
thrombocytopenia
(HIT)
or
thrombotic
thrombocytopenia purpura. More than one-half of patients
exposed to heparin will develop antibodies after heparin
administration, and more than 65% of patients undergoing
cardiac surgery in which heparin is used will develop them.
The reason for the increase in cardiac surgical patients is not
clear. Despite the propensity to form antibodies, the incidence
of HIT in intensive care unit patients is quite low (0.1-3%,
depending on the series reported).
C
Hypokalemia is one of the most common electrolyte
abnormalities encountered in medicine and in the intensive
care unit in particular. Because the majority of potassium is
intracellular/ serum levels do not reflect total body potassium.
Although most hypokalemic patients are asymptomatic, the
clinical concern is the potential for cardiac arrhythmias,
especially when it is accompanied by heart failure. Muscular
symptoms, when present, include weakness, fasciculations,
and tetany. Gastrointestinal symptoms may include ileus,
nausea, vomiting, and constipation. Potassium loss may result
from diuretics, gastrointestinal loss, nephrotoxic drugs, some
chemotherapeutic agents, and especially diarrhea, as in this
case. Hypokalemia is also seen in some genetic syndromes
(e.g., Bartter disease). Additional electrolyte loss, including
5
Platelet factor 4 (PF4), a positively charged protein released
from alpha-granules in platelets, preferentially binds to the
negatively charged heparin molecule even to the point that it
will displace PF4 from its natural binding on vascular
endothelium. The PF4-heparin complex (PF4/H) results in
platelet aggregation and is a potent activator of B-cell
production of an antibody against PF4/H, augmented by
10,000 times if the PF4/H is complement-coated. Most
antibodies are IgG. IgM and IgA have also been identified,
although their role in HIT is uncertain. The antibody-PF4/H
complex bids to the FcƳlla receptor on monocytes,
stimulating the release of procoagulant microparticles, tissue
factor, and activated thrombin. This mechanism is believed to
be the process by which spontaneous thrombosis in HIT
occurs, further reducing platelet numbers.
risk for HIT by either of these systems were identified as HITpositive when laboratory tests were obtained, and many
patients judged to be high risk did not demonstrate laboratory
confirmation of HIT, these systems should not be used alone
to make therapeutic decisions. They probably are best used to
indicate which patients require further laboratory
investigation.
The most common laboratory test used is the immunoassay
(ELISA) for the anti-PF4/H antibodies. The test does not
selectively identify the IgG antibody. Because many patients
who receive heparin develop antibodies without overt HIT,
the false-positive rate is quite high, leading to risky
overtreatment. Because the assay uses an optical density
(OD) measurement, the test is prone to operator error.
Further, the OD threshold for positivity is variable. The test
does demonstrate an excellent negative predictive value and
is generally available in most laboratories. The radiolabeledserotonin release assay (14C-SRA) is considered the standard
of care, but the assay is costly, requires radioactive
substances, requires specialized equipment and expertise, and
is not universally available. Many other laboratory tests are
more accurate but are not as widely available.
Because thrombocytopenia is a common finding in the
intensive care unit, several scoring systems can aid the
clinician in determining which patients are at risk for HIT.
The most common is Warkentin 4T system, outlined in
table 9.1.
Another system, the HEP-score, incorporates the features of
the 4T-score, expands some of them, and adds others in a
more quantitative fashion. The HEP-score improves the
accuracy of probability estimates of HIT being present, but at
the cost of adding complexity and being cumbersome to use
at the bedside. Because patients who were found to be a low
The approach to the patient with suspected HIT is to initiate
immediate discontinuation of heparin and to perform a risk
assessment using one of the tools described. Based on that
score, a decision can be made regarding the need for further
Points (0,1, or 2 for each of 4 categories: maximum possible score = 8)
2
>50% platelet fall to nadir≥20
1
30-50% platelet count fall (or
>50% directly resulting from
surgery); or nadir 10-19
0
<30% platelet fail; or
nadir<10
Timinga of platelet count
fall, thrombosis, or other
sequelae (1st day of
putative immunizing
exposure to heparin = day
0)
Days 5-10 onseta (typical/
delayed onset HIT); or ≤ 1 day
(with recent heparin exposure)
or within 30 days (rapid-onset
HIT)
Platelet count fail <4
days (unless picture of
rapid-onset HIT)
Thrombosis or other
sequelae (e.g., skin
lesions, anaphylactoid
reactions)
Proven new thrombosis; or
skin necrosis (at injection
site); or postintervention
heparin bolus anaphylactoid
reaction
No explanation for platelet
count fail is evident
Consistent with days 5-10 fall,
but not clear (e.g., missing
platelet counts); or ≤ 1 day
(heparin exposure within the
past 31-100 days) (rapid-onset
HIT); or platelet fall after day
10
Progressive or recurrent
thrombosis; or erythematous
skin lesions (at injection site);
or suspected thrombosis (not
proven); hemofilter thrombosis
Possible other cause is evident
Thrombocytopenia
Other cause for
thrombocytopenia
None
Definite other cause is
present
Pretest probability score: 6-8 = high; 4-5 = intermediate; 0-3 = low
HIT = heparin-induced thrombocytopenia.
a
First day of immunizing heparin exposure considered day 0; the day the platelet count begins to fall Is considered the day of
onset of thrombocytopenia (It generally takes 1-3 more days until an arbitrary threshold that defines thrombocytopenia is
passed). Usually, heparin administered at or near surgery is the most immunizing situation (i.e., day 0).
*
Table 9.1. The 4Ts scoring system.
6
laboratory investigation. Initially, an immunoassay is
requested; if positive, a confirmatory 14C-SRA should be
obtained. If the immunoassay is negative, heparin may safely
be continued. A positive immunoassay then prompts the
clinical decision as to whether some form of anticoagulation,
either therapeutic or prophylactic, is required. When the
patient has evidence of thrombosis (HITT), a direct thrombin
inhibitor should be instituted. Both arterial and venous
thrombosis have been reported with HITT. At the time of this
writing, argatroban is the only drug approved by the US Food
and Drug Administration, although there are reports of the
off-label use of other direct thrombin inhibitors, as well as
fondaparinux, in this clinical setting.
characteristics and the clinical situations that necessitated
the need for a contrast-enhanced imaging study [e.g.,
coronary versus peripheral vascular angiography], urgent
versus elective procedure, specific contrast material used as
well as the volume administered, and many others). To
complicate matters further, a multitude of published metaanalyses have directly conflicting results.
It is less complicated to identify patients who may be at
increased risk for CI-AKI: those with pre-existing renal
dysfunction, chronic congestive heart failure, diabetes,
hypertension, and advanced age. The use of multipleiodinated contrast media is also a factor. In addition, patients
who are volume depleted are at increased risk for CI-AKI.
This has led to the consistent recommendation that
intravenous volume infusion is the mainstay of prevention.
Dispute continues over which intravenous fluid should be
used, sodium chloride versus a bicarbonate solution. The use
of N-acetylcysteine shows conflicting results in reducing CIAKI; however, along with bicarbonate, there is no evidence
of harm. Statins have been used successfully in some studies
but not in others, and controversy exists over the dose and
duration of treatment. Renal-dose (low-dose) dopamine has
no effect on reducing the incidence of CI-AKI or the duration
if it occurs.
Platelet transfusion is not recommended due to the theoretical
risk of enhancing PF4/H antibody production, platelet
aggregation, and perhaps sensitization of the patient to
exogenous platelets. There is no direct evidence that platelet
transfusion is contraindicated; it is simply not necessary
unless the patient is actively bleeding. Streptokinase is not
indicated due to the bleeding risk, especially for postoperative
patients with thrombocytopenia. Enoxaparin, a lowmolecular weight heparin, is not approved for use in this
clinical setting, although low molecular weight heparins are
less associated with HIT than unfractionated heparins.
Warfarin is contraindicated due to the propensity for
producing acquired protein C deficiency and lower extremity
venous thrombosis and necrosis during the thrombocytopenic
phase of HIT. Cutaneous necrosis has also been reported.
10. What is an effective strategy to minimize risk for acute
kidney injury in a polytrauma patient expected to receive
multiple contrast-enhanced imaging studies?
11. A 48-year-old woman with a history of deep venous
thrombosis treated with rivaroxaban presents with 12 hours
of right upper quadrant pain. Physical examination,
laboratory values, and ultrasound are consistent with acute
cholecystitis. Laparoscopic cholecystectomy is planned.
Given her normal renal function coagulation profile when
will her coagulation profile normalize?
A.
B.
C.
D.
E.
A.
B.
C.
D.
E.
N-acetylcysteine
Sodium bicarbonate
"Renal dose" dopamine
Intravenous volume infusion
Statin therapy
Answer:
D
6 hours
12 hours
36 hours
72 hours
96 hours
Answer:
The prevention of contrast-induced acute kidney injury (CIAKI) is a contentious issue in the medical literature, and to
date there remains significant equipoise regarding the most
effective strategy. Fortunately, CI-AKI is uncommon,
occurring in 1 to 5% of patients undergoing a contrastenhanced imaging study; however, the results can have a
profound impact on outcome. All reported trials suffer from
one or more of the following: methodological flaws, small
patient numbers, heterogeneity in the definition of CI-AKI,
ill-defined or possibly inappropriate endpoints (e.g., rise in
serum creatinine, arbitrary reduction in glomerular filtration
rate, need for dialysis or renal replacement therapy,
mortality, duration of CI-AKI, potential pleiotropic effects
of pharmacological strategies used, inconsistent patient
C
Rivaroxaban is a direct oral anticoagulant (DOAC),
commonly used in patients diagnosed with venous
thromboembolic events, which inhibits Factor Xa. The halflife of this anticoagulant is 9 to 13 hours, and its therapeutic
activity wears off after 4 to 5 half-lives. Therefore,
rivaroxaban should be discontinued at least 24 hours before a
surgical procedure. In patients with a reduced creatinine
clearance, this recommendation is changed to 3 to 5 days.
Although reversal of the DOAC is possible, the risk of a
thrombotic event during reversal should be weighed against
the urgency of surgery. For a patient with acute cholecystitis,
her coagulation profile will normalize at 24 to 36 hours after
her last oral dose.
7
B. has a morbidity rate comparable with total
cholecystectomy.
C. is followed by postoperative endoscopic retrograde
cholangiopancreatography in 40% of patients.
D. is optimally performed with a fenestrating rather than a
reconstituting technique.
E. is not a definitive procedure.
12. A 55-year-old man with perforated diverticulitis is
undergoing a laparotomy, Segmental resection of the sigmoid
was performed after a difficult dissection. The patient is on
norepinephrine and vasopressin infusions, and his arterial
blood gases are as follows:
pH = 7.05
PaCO2 = 22 mm Hg
PaO2 = 89 mm Hg
HCO3- = 13 mEq (20-29 mEq)
Oxygen saturation = 91%
Base deficit = -19 mEq/L Temperature = 35°C
What is the most appropriate next step?
Answer:
In cases of acute cholecystitis with significant inflammation
or a fibrosed gallbladder, subtotal cholecystectomy is
advocated. Subtotal cholecystectomy can be performed
laparoscopically and involves removing the front wall of the
gallbladder and all intraluminal stones. Both fenestrating
(leaving the infundibulum/cystic duct orifice open with
placement of a drain in Morison pouch) and reconstituting
(closure of a cuff of infundibulum over the top of the cystic
duct orifice) techniques are described, with reported
equivalent outcomes.
A. Leave the bowel in discontinuity with a temporary
abdominal closure
B. Mature an end colostomy with a temporary abdominal
closure
C. Mature an end colostomy, closing the fascia, leaving the
skin open
D. Perform a primary anastomosis with a primary
abdominal closure
E. Perform a primary anastomosis, with a diverting loop
ileostomy, and primary abdominal closure
Answer:
B
This procedure is safe and feasible, particularly in cases in
which conversion to an open procedure will not better
delineate the inflamed triangle of Calot. It can be a definitive
procedure, with less than 5% of patients needing additional
surgery. The morbidity rate is comparable with total
cholecystectomy, with a reported 7 to 18% rate of bile leak
and
need
for
endoscopic
retrograde
cholangiopancreatography in 4 to 20% of patients.
A
Damage control surgery, abbreviating a laparotomy in the
physiologically exhausted patient, has been used for several
decades in trauma to improve mortality. The utility of
damage control techniques is increasingly recognized in the
acidotic, hypothermic, coagulopathic general surgery
patient. Arresting surgical bleeding and limiting enteric
contamination is followed by temporary abdominal closure
with resuscitation and physiologic restoration in the
intensive care unit. Definitive repair of injuries and
restoration of gastrointestinal continuity is delayed until
second laparotomy.
Items 14-15
A 76-year-old woman with atrial fibrillation on warfarin
presents with acute cholecystitis. She is started on antibiotics
and is scheduled to undergo laparoscopic cholecystectomy
once her international normalized ratio of 2.5 (0.8-1.2) has
been reversed. Her medical history is significant for
congestive heart failure, hypertension, and diabetes.
This patient is in septic shock requiring multiple
vasopressors; additionally he is hypothermic and markedly
acidotic. Segmental resection of the septic source should be
performed. The optimal next step is to leave the stapled-off
ends of the colon in discontinuity, apply a temporary
abdominal closure, and transport the patient to the intensive
care unit for correction of his acidosis, hypothermia, and
shock. Further time in the operating room is not warranted.
Once fully resuscitated, the patient may be returned to the
operating room for definitive management and abdominal
closure.
14. In an attempt to determine whether anticoagulant bridge
therapy is needed, which of the following individual risk
factors portends the highest risk of stroke if using the
CHA2DS2-VASc risk assessment tool?
A.
B.
C.
D.
E.
Age
Congestive heart failure
Hypertension
Diabetes
Female sex
15. She is determined to be at moderate risk for a
perioperative stroke based on the CHA2DS2-VASc risk
assessment tool. In this patient, anticoagulant bridging
therapy should
13.
Laparoscopic subtotal cholecystectomy for acute
cholecystitis
A. not be instituted.
B. be instituted with intravenous unfractionated heparin.
A. requires a reoperation in 20% of patients.
8
C. be instituted with subcutaneous enoxaparin.
D. be instituted with intravenous dalteparin.
E. be instituted with subcutaneous fondaparinux.
Answers:
variables and is a reliable means to determine the Frailty
status of patients. These variables can be grouped into one
of 4 categories: comorbidities, activities of daily living,
attitude, and nutrition. The important comorbidities are
previous history of cancer, hypertension, coronary heart
disease, or dementia. The activities of daily living include
whether the patient needs help with grooming, managing
finances, performing housework, toileting, and walking.
Assessment of attitude includes whether the patient feels
less useful, is depressed, is lonely, and is sexually active.
Nutrition is assessed with a serum albumin, with an albumin
of less than 3 mg/dL (3.5-5.2 mg/dL) contributing to the
frailty score.
A, A
Anticoagulant bridge therapy for patients with atrial
fibrillation who undergo an invasive procedure reduces the
time that a patient will not be therapeutically anticoagulated,
thereby reducing the overall risk of a thrombotic event.
Recent studies have determined that the overall risk of
thrombosis is much lower than previously cited and is not
necessarily less with bridging therapy. The risk of bleeding
must be balanced by the risk of thrombosis. When assessing
the perioperative risk of stroke, the American College of
Cardiology has stratified patients based on their risk of
thromboembolism. The CHA2DS2-VASc score was
developed after the CHADS2 score and evaluates more risk
factors to estimate the risk of stroke in patients with atrial
fibrillation. Aside from a previous risk of stroke or transient
ischemic attack, of the choices listed, age 75 or older
portends the highest risk of stroke when using the
CHA2DS2-VASc risk assessment tool.
Patients determined to be frail by this index are more likely
to have postoperative complications compared with nonfrail
patients. Age, sex, American Society of Anesthesiologists
score, and cardiovascular status are not independently
predictive of the likelihood of developing postoperative
complications in this patient population. These findings
suggest that physiologic reserve is the best predictor of
postoperative complications in patients older than 65.
17. A previously healthy patient presents with peritonitis
secondary to perforated diverticulitis. After adequate source
control, she should receive 4 days of
The risk of stroke must be balanced by the risk of bleeding
when determining the need for anticoagulant bridging therapy
in patients with atrial fibrillation who undergo an invasive
procedure. According to the American College of
Cardiology's 2017 consensus guidelines, bridging
recommendations are based on stroke risk (CHA 2DS2-VASc
tool) and bleeding risk. For this patient who is deemed
moderate risk (CHA2DS2-VASc score 5-6 or prior stroke/TIA
at least 3 months previously) of stroke with increased risk of
bleeding (intra-abdominal surgery; i.e., laparoscopic
cholecystectomy), anticoagulant bridging therapy is not
recommended.
Unfractionated
heparin,
enoxaparin,
dalteparin, and fondaparinux are suitable alternatives for
anticoagulation when bridging therapy is indicated.
A.
B.
C.
D.
E.
Answer:
As a result of her perforated diverticulitis, this patient is at
higher risk of developing a complicated intra-abdominal
infection. Owing to its broader spectrum of antibiotic
activity, piperacillin-tazobactam is the best antibiotic for the
treatment of this patient.
American Society of Anesthesiology score.
age.
the Frailty index.
sex.
cardiovascular status.
Answer:
E
Recent randomized clinical trials demonstrated that in
patients with intra-abdominal infections in whom adequate
source control is achieved, antibiotic therapy for a fixed
duration of 4 days achieves equivalent outcomes compared
with longer courses of antibiotic therapies based on
administering antibiotics for 2 days beyond the resolution of
fever, leukocytosis, or ileus.
16. In patients over the age of 65 undergoing emergency
general surgery, the likelihood of developing postoperative
complications is best predicted by
A.
B.
C.
D.
E.
gentamicin.
tigecycline.
clindamycin.
fluconazole.
piperacillin-tazobactam.
Aminoglycosides, such as gentamicin, should not be
routinely used for empiric therapy. Instead, they should be
reserved for the treatment of Gram-negative infections that
are resistant to other antibiotics and are documented to be
sensitive to aminoglycosides.
C
In patients over the age of 65 undergoing emergency general
surgery, the likelihood of developing perioperative
complications is best predicted by the Frailty index. The
emergency general surgery frailty index consists of 15
Similarly, tigecycline should not be used for the empiric
treatment of intraabdominal infections. It should be reserved
for patients with resistant pathogens, particularly as a
component of a combination regimen.
9
Clindamycin should be used only as an antianaerobic agent
for the empiric treatment of intra-abdominal infection as part
of a combination regimen when metronidazole cannot be
used. Antifungal agents, such as fluconazole, are not
recommended for empiric therapy for intra-abdominal
infection. If antifungal agents are necessary, echinocandins
are preferred over azoles.
be stopped immediately. If succinylcholine has been
previously administered, it should not be read ministered.
Dantrolene is the treatment of choice. It should be prepared
and administered immediately in doses of 2.5 mg/kg.
Dantrolene acts by inhibiting the ryanodine receptor (RyRl)
channel which reduces the RyRl channel activity in muscle
cells. Susceptibility to malignant hyperthermia is inherited
as an autosomal dominant condition and is characterized by
a defect in the ryanodine receptor, resulting in a
dysfunctional calcium channel located in the cytoplasmic
membrane.
18. A 40-year-old man is undergoing a laparoscopic
cholecystectomy. At the time of attempted port placement,
the patient's abdominal wall is extremely rigid. The
anesthesiologist notices that the patient is hyperventilating
and there has been a sudden increase in the end tidal CO2
concentration. The patient begins having recurrent 10-beat
runs of ventricular tachycardia. His arterial blood gas
demonstrates a pH of 7.10, a PaCO2 of 65, a base deficit of 10, and a lactate of 8 mg/dL (4.5-19.8 mg/dL). His
temperature is 37.5°C. A drug that is helpful in this condition
is
A.
B.
C.
D.
E.
Patients in whom the onset of malignant hyperthermia is
suspected should be immediately cooled using all routes
available, including the administration of intravenous saline
at 4°C, topical ice to all exposed areas, and peritoneal
washing with cold saline. Nasogastric lavage and bladder
irrigation are not recommended.
Administration of calcium to a patient with malignant
hyperthermia is contraindicated, because it can worsen the
clinical syndrome. While the administration of sodium
bicarbonate can temporize the systemic acidosis, it does
nothing to prevent the progression of malignant
hyperthermia. If repeated and sustained runs of ventricular
dysrhythmias are present, amiodarone, not lidocaine, is the
antiarrhythmic agent of choice.
succinylcholine.
sodium bicarbonate.
lidocaine.
calcium.
dantrolene.
Answer:
E
19. Which of the following is considered a serious reportable
surgical event?
Malignant hyperthermia (MH) is a pharmacogenetic
disorder that may occur at any time during general
anesthesia or the early postoperative period. The physiologic
derangement leading to the development of MH is
uncontrolled hypermetabolism. This uncontrolled
hypermetabolism leads to respiratory acidosis and, in most
cases, metabolic acidosis due to the rapid consumption of
adenosine triphosphate within cells. The etiology is an
uncontrolled release of intracellular calcium from the
sarcoplasmic reticulum of skeletal muscle. The enhanced
intracellular calcium results in abnormal skeletal muscle
metabolism, which causes skeletal muscle contraction,
rigidity, and increased oxygen consumption and CO2
production.
A. Intraoperative death in an American Society of
Anesthesiologists class IV patient
B. Lack of a timeout before a surgical procedure
C. Lack of a site marking before exploratory laparotomy
D. Deep surgical site infection after colorectal surgery
E. Wrong site surgery
Answer:
E
The National Quality Forum has endorsed serious reportable
events (SREs) in healthcare. These were initially released in
2002 and updated in 2011. The purpose of the SREs is to
have a uniform and comparable public reporting system that
facilitates systematic learning and drives national
improvement across healthcare organizations. The 2011
update defines 5 surgical or invasive procedure serious
reportable events:
In humans, clinical malignant hyperthermia results most
often from exposure to anesthetic agents. All inhalation
anesthetics, except nitrous oxide, are triggers for malignant
hyperthermia. The muscle relaxant succinylcholine is also a
well-described trigger for the onset of malignant
hyperthermia. Early recognition of MH is key to successful
treatment. Patients will manifest tachycardia, a rise in the
end-expired CO2 concentration (despite an increase in
minute ventilation), and muscle rigidity.
1.
2.
3.
For any patient in whom the onset of malignant
hyperthermia is suspected, all inhalation anesthetics should
4.
10
Surgery or other invasive procedure performed on the
wrong site.
Surgery or other invasive procedure performed on the
wrong patient.
Wrong surgical or other invasive procedure performed
on a patient.
Unintended retention of a foreign object in a patient
after surgery or other invasive procedure.
5.
Intraoperative or immediately
postoperative/postprocedure death in an American
Society of Anesthesiologists class I patient.
Management of antiplatelet therapy in the setting of coronary
disease and stents continues to evolve. Both the risk of stent
thrombosis and the risk of bleeding must be assessed. In this
case, the risk of bleeding is low (it would be higher with a
mastectomy with reconstruction; table 20.1) and the risk of
thrombosis is low (table 20.2). Discontinuing the clopidogrel
and continuing the aspirin is reasonable.
Timeouts were widely adopted as a method to prevent SREs;
however, not performing a timeout does not constitute an
SRE. Site marking is highly recommended, especially when
there is laterality or level. In many institutions, site marking
is not required for an exploratory laparotomy. Although a
deep surgical site infection is a known complication of
colorectal procedures, it does not fall into any of the surgical
or invasive procedure SREs.
Management of dual antiplatelet therapy in patients
undergoing surgery is a balance between risk of bleeding and
thrombosis (table 20.3). Stopping these agents places the
patient at risk for major adverse cardiac events, while
continuing one or both agents is a risk for major bleeding.
Thrombotic risk appears to be time dependent. If elective
surgery can be delayed to reduce the risk, it is a viable option.
If surgery cannot be delayed and bleeding risk is high,
continuing aspirin and holding the clopidogrel is suggested.
Restarting clopidogrel should occur as soon as possible and
preferably within 72 hours.
20. A 64-year-old woman has a 2-cm area of ductal
carcinoma in situ in her left breast. She has a history of having
had 4 bare metal stents placed 2 years ago during an acute
coronary event. She has had no chest pain. She takes
clopidogrel and a baby aspirin every day. In preparation for
her partial mastectomy, she should
A.
B.
C.
D.
E.
stop both the aspirin and the clopidogrel.
keep taking both the aspirin and the clopidogrel.
stop the aspirin and keep taking the clopidogrel.
stop the clopidogrel and keep taking the aspirin.
stop both the aspirin and clopidogrel and start
enoxaparin.
Answer:
D
Low Risk
Intermediate Risk
High Risk
General, orthopedic, and urologic surgeries
Hernioplasty, plastic surgery of
Incisional hernias, cholecystectomy,
appendectomy, colectomy, gastric
resection, intestinal resection, breast
surgery, hand surgery, arthroscopy,
cystoscopy and ureteroscopy
Hemorrhoidectomy, splenectomy,
gastrectomy, bariatric surgery, rectal
resection, thyroidectomy, prosthetic
shoulder, knee, foot and major spine
surgery, prostate biopsy, orchiectomy
Hepatic resection,
duodenocefalopancreasectomy, hip,
major pelvic and proximal femur
fracture surgery, nephrectomy,
cystectomy, TURP, TURBT,
prostatectomy
Carotid endarterectomy, bypass or
endarterectomy of lower extremity,
EVAR, TEVAR, limb amputations
Open abdominal aorta surgery
Open thoracic and thoracoabdominal
surgery
Cardiac surgery
Mini-thoracotomy, TAVR (apical
approach), OPCAB, CABG, valve
replacement
Reintervention, endocarditis, CABG in
PCI failure, aortic dissections
Vascular surgery
CABG = coronary artery bypass graft; EVAR = endovascular aortic aneurysm repair; OPCAB = off-pump coronary artery
bypass;
PCI = percutaneous coronary intervention; TAVR = transcatheter aortic valve replacement; TEVAR = thoracic endovascular
aortic aneurysm repair; TURBT = transurethral resection of bladder tumor; TURP = transurethral resection of prostate.
Table 20.1. Determination of hemorrhagic risk of noncardiac and cardiac surgeries.
11
low Risk
>4 weeks after PCI with POBA
Intermediate Risk (1%-5%)*
High Risk (>5%) *
>2 weeks and ≤ weeks after PCI with POBA <2 weeks after PCI with POBA
>6 months after PCI with BMS
>1 month and months after PCI with BMS
≤1 month after PCI with BMS
>12 months after PCI with DES
>6 months and ≤12 months after PCI with
DES
≤6 months after PCI with DES
>12 months after complex PCI with DES
(long stents, multiple stents, overlapping,
small vessels, bifurcations, left main, last
remaining vessel)
≤12 months after complex PCI with
DES
≤6 months after PCI for Ml Previous
ST
*30-day ischemic event rates of cardiovascular death and Ml.
BMS = bare-metal stent(s); DES = drug-eluting stent(s); Ml = myocardial infarction; PCI = percutaneous coronary
intervention; POBA - plain old balloon angioplasty ; ST « stent thrombosis.
Table 20.2. Determination of thrombotic risk.
Thrombotic Risk
Hemorrhagic Risk
Low risk
Intermediate risk
High risk
Low Risk
Intermediate Risk
High Risk
Continue ASA; discontinue
Postpone elective surgery.
Postpone elective surgery.
P2Y12 receptor Inhibitor; resume If surgery nondeferrable:
If surgery nondeferrable: continue
within 24-72 h with a loading continue ASA; discontinue
ASA and
dose
P2Y12 receptor inhibitor; resume P2Y12 receptor Inhibitor
within 24-72 h with a loading perioperatively
dose
Continue ASA; discontinue
Postpone elective surgery.
P2Y12 receptor Inhibitor; r
If surgery nondeferrable:
Postpone elective surgery; if surgery
esume within 24-72 h with a
continue ASA; discontinue
nondeferrable: continue ASA;
loading dose
P2Y1Z receptor inhibitor; resume discontinue P2Y12 receptor
within 24-72 h with a loading inhibitor, resume within 24-72 h
dose
with a loading dose; consider
bridging with shortacting IV APT
Continue ASA; discontinue
Postpone elective surgery.
Postpone elective surgery, if surgery
P2YIZ receptor Inhibitor; resume If surgery nondeferrable:
nondeferrable: continue ASA;
within 24-72 h with a loading continue ASA; discontinue
discontinue P2Y12 receptor
dose
P2Y1Z receptor inhibitor, resume inhibitor; resume within 24-72 h
within 24-72 h with a loading with a loading dose; consider
dose
bridging with short-acting IV APT
APT = antiplatelet therapy; ASA = aspirin; IV = intravenous.
Table 20.3. Perioperative management of DAPT.
12
21. Which of the following is associated with an increased
rate of surgical site infection in patients undergoing elective
ventral hernia repair with class 1 wounds?
A.
B.
C.
D.
E.
Answer:
E
Nearly half of surgical site infections (SSIs) are preventable.
In this era of public reporting and decreasing reimbursement
for hospital acquired infections, evidence-based strategies
must be applied to surgical patients. The Centers for Disease
Control and Prevention Guidelines for the Prevention of
Surgical Site Infection (2017) provided new and updated
evidence-based recommendations for the prevention of SSL
Prehospital recommendations are shown in table 21.1. Inhospital recommendations are shown in table 21.2
Hyperthermia
Hypoglycemia
Facility laundering of scrubs
Clipping hair around surgical site
Mechanical bowel prep
Guideline
1.1. Preoperative
bathing
Intervention
Routine preoperative bathing with chlorhexidine (when not part of a decolonization protocol or
preoperative bundle) decreases skin surface pathogen concentrations but has not been shown to reduce
SSI.
1.2. Smoking
cessation
Smoking cessation 4 to 6 weeks before surgery reduces SSI and Is recommended for all current smokers,
especially those undergoing procedures with implanted materials. There is no literature to support
cessation of marijuana and electronic cigarette use to prevent SSI, but cessation is recommended before
surgery based on expert consensus.
American College of Surgeons patient education materials support the use of nicotine lozenges, nicotine
gum, and medication to aid in smoking cessation.
1.3. Glucose control
Optimal blood glucose control should be encouraged for all diabetic patients; however, there is no
evidence that improved Hgb A1C decreases SSI risk.
1.4. MRSA
screening
Decision about whether or not to Implement global Staphylococcus aureus screening and decolonization
protocols should depend on baseline SSI and MRSA rates.
Clinical practice guidelines from the American Society of Health-System Pharmacists recommend
screening and nasal mupirocin decolonization for S aureus-colonized patients before total joint
replacement and cardiac procedures.
MRSA bundles (screening, decolonization, contact precautions, hand hygiene) are highly effective if
adhered to, otherwise there is no benefit.
No standard decolonization protocol supported by literature; consider nasal mupirocin alone vs nasal
mupirocin plus chlorhexidine gluconate bathing.
Decolonization protocols should be completed close to date of surgery to be effective.
Vancomycin should not be administered as prophylaxis to MRSA-negative patients.
Table 21.1. Prehospital interventions.
Guideline
Intervention
2.1. Glucose control
Hyperglycemia in the immediate preoperative period Is associated with an increased risk of SSI.
Target perioperative blood glucose should be between 110 to 150 mg/dL in all patients, regardless
of diabetic status, except in cardiac surgery patients where the target perioperative blood glucose is
<180 mg/dL.
Target blood glucose rates <110 mg/dL have been tied to adverse outcomes and increased episodes
of hypoglycemia and do not decrease SSI risk.
22. Hair removal
Hair removal should be avoided unless hair interferes with surgery. If hair removal is necessary,
clippers should be used instead of a razor.
2.3. Skin preparation
Alcohol-containing preparation should be used unless contraindication exists (eg fire hazard,
surfaces involving mucosa, cornea, or ear).
No dear superior agent (chlorhexidine vs iodine) when combined with alcohol.
If alcohol cannot be induced in the preparation, chlorhexidine should be used instead of iodine
unless contraindications exist
2.4. Surgical hand
scrub
Use of a waterless chlorhexidine scrub is as effective as traditional water scrub and requires less
time, but there is no superior agent If used according to manufacturer instructions.
SSI, surgical site infection.
Table 21.2a. Hospital interventions.
13
Guideline
Intervention
2.5. Surgical attire
There is limited evidence to support recommendations on surgical attire.
Joint Commission and Association of Perioperative Registered Nurses policies support
facility scrub laundering and the use of disposable bouffant hats.
American College of Surgeons guidelines support the use of a skull cap if minimal hair is
exposed, removing or covering all jewelry on the head and neck, and professional attire
when outside the operating room (no scrubs or clean scrubs covered with a white coat).
2.6. Antibiotic
prophylaxis
Administer prophylactic antibiotics only when Indicated.
Choice of prophylactic antibiotic should be dictated by the procedure and pathogens most
likely to cause SSI.
Prophylactic antibiotic should be administered within 1 hour before incision or within 2
hours for vancomycin or fluoroquinolones.
Prophylactic antibiotic dosing should be weight-adjusted.
Re-dose antibiotics to maintain adequate tissue levels based on agent half-life or for
every
1,500 mL blood loss
There is no evidence that prophylactic antibiotic administration after incision closure
decreases SSI risk; prophylactic antibiotics should be discontinued at time of incision
closure (exceptions include implant-based breast reconstruction, joint arthroplasty, and
cardiac procedures where optimal duration of antibiotic therapy remains unknown).
2.7. Intraoperative
normothermia
Maintain intraoperative normothermia to reduce SSI risk. Preoperative warming is
recommended for all cases, and intraoperative warming methods should be employed for
all but short, dean cases.
2.8. Wound protectors
Use of an impervious plastic wound protector can prevent SSI in open abdominal
surgery. Evidence is strongest for elective colorectal and biliary tract procedures.
2.9. Antibiotic sutures
Triclosan antibacterial suture use is recommended for wound closure in dean and deancontaminated abdominal cases when available.
2.10. Gloves
The use of double gloves is recommended.
Changing gloves before closure in colorectal cases is recommended, however,
rescrubbing before closure in colorectal cases is not recommended.
2.11. Instruments
2.12. Wound closure
The use of new instruments for closure in colorectal cases is recommended.
No high-quality evidence about delayed primary closure vs primary closure and SSI for
contaminated and dirty incisions.
Purse-string closure of stoma sites recommended over primary closure.
2.13. Topical antibiotics
Topical antibiotics can reduce SSI for specific cases, including spine surgery, total joint
arthroplasty, and cataract surgery, but there is insufficient evidence to recommend
routine use at this time.
2.14. Supplemental
oxygen
The administration of supplemental oxygen (80%) is recommended in the immediate
postoperative period after surgery performed under general anesthesia.
2.15. Wound care
There is no evidence in the literature that timing of dressing removal increases SSI risk.
Early showering (12 hours postoperative) does not increase the risk of SSI.
Use of wound vacuum therapy over stapled skin can reduce SSI In open colorectal
(abdominal Incision) and vascular (groin incision) cases.
Mupirocin topic antibiotic application can decrease SSI compared with a standard
dressing. Daily wound probing can decrease SSI in contaminated wounds.
SSI, surgical site infection.
Table 21.2b. Hospital interventions (continued).
14
Additional prophylactic antimicrobial agent doses are not
necessary after closure, even in the presence of a drain for
clean and dean-contaminated cases. Topical antimicrobial
agents in the surgical incision should not be used.
protein kinases BRAF or MEK. About half of all melanoma
possess such mutations. Anti-BRAF drugs include
dabrafenib and vemurafenib. Anti-MEK drugs include
trametinib and binimetinib. These agents are given orally
and work rapidly, but they are limited by rapid drug
resistance and toxidties, including skin rashes and secondary
skin cancers. Giving BRAF and MEK inhibitors together
seems to improve their efficacy, and the US Food and Drug
Administration has approved these agents alone and in
combination.
In an analysis of a large hernia registry, for those patients with
a dean wound (e.g., no skin breakdown, strangulation), a
preoperative bowel preparation was associated with a higher
rate of SSIs. Hair removal should be avoided unless it
interferes with the procedure. Hair removal, if needed, should
be done with clippers rather than a razor because the latter is
associated with higher rates of SSIs. Although the Joint
Commission and the Association of Perioperative Registered
Nurses support facility scrub laundering, data are insufficient
to associate this with decreased SSI rates.
The second type of newer agents are checkpoint inhibitors,
monoclonal antibodies that block the checkpoint receptors
that are present on the surface of cytotoxic T cells and
normally serve to downregulate these cells and induce
natural apoptosis. Many tumors can ligate these receptors,
"turning off" antigen-specific T cells important in tumor
killing. Thus, agents that block checkpoint receptors or their
ligands are immunotherapies that serve to augment
antitumor T cell response. Unlike MAP kinase inhibitors/
these drugs do not require a specific tumor mutation to be
effective, because all T cells express these receptors. The 2
main checkpoints targeted to date are cytotoxic Tlymphocyte associated antigen-4 (CTLA-4) and the PD-1
receptor. Examples of anti-CTLA-4 drugs include
ipilimumab and tremelimumab, and examples of anti-PD-1
agents include nivolumab and pembrolizumab. These agents
are given intravenously, and autoimmune toxidties are
uncommon but serious, including colitis and
endocrinopathies. Like MAP kinase inhibitors, the US Food
and Drug Administration approved these agents alone or in
combination. Unlike MAP kinase inhibitors, responses can
be slower (including a potential period of
"pseudoprogression" in which tumors appear to enlarge due
to swelling) but more durable.
Items 22-25
Each lettered response may be selected once, more than once,
or not at all.
A.
B.
C.
D.
E.
Pembrolizumab
Ipilimumab
Dabrafenib
Trametinib
Imatinib
22. Anti-CTLA-4
23. Anti-PD-1
24. Anti-MEK
25. Anti-BRAF
Answer:
B, A, D, C
One due to remembering and understanding biologic agents
is to understand how they are named. Monoclonal antibodies
(MoAbs) end with the suffix "-mab." Chimeric humanmouse MoAbs end with "-ximab" (e.g., rituximab),
humanized mouse MoAbs end with "-zumab" (e.g.,
bevadzumab), and human MoAbs end with "-mumab" (e.g.,
ipilimumab).
Newer drugs have completely changed the landscape of
treating advanced melanoma. General surgeons should be
aware of these newer agents for 3 reasons. First, these drugs
can cause side effects that may require surgical intervention,
such as skin lesions and colitis that occasionally progresses
to bowel perforation. Second, these agents may significantly
downstage unresectable tumors, making the tumors
potentially resectable. Surgeons should work with
oncologists to plan the potential resection of tumors treated
with these agents in a neoadjuvant fashion. Finally,
indications for these drugs, especially anti-programmed
death-1 (PD-1) agents, are being extended from melanoma
to a variety of cancers, including non-small cell lung,
advanced urothelial (bladder and renal), advanced Merkel
cell, and head and neck cancers, as well as relapsed
lymphomas, just to name a few. Thus, they are rapidly
affecting the overall care of multiple cancers.
Small molecule inhibitors end with the suffix "-ib." Tyrosine
kinase inhibitors end with the suffix "-tinib" (e.g., imatinib),
proteasome inhibitors end with "-zomib" (e.g., bortezomib),
and cyclin-dependent kinase inhibitors end with "-dclib"
(e.g., selidclib). MEK is part of the tyrosine kinase pathway,
hence "trametinib."
Also, drug names sometimes indude the name of the target
(e.g., dabrafenib contains "BRAF").
26. The preoperative removal of hair from surgical sites
These new agents are of 2 general types. First, selective
inhibition of the mitogen-activated protein (MAP) kinase
pathway can be done by blocking mutated forms of the
A. is recommended by the Centers for Disease Control and
Prevention.
15
B.
C.
D.
E.
does not reduce the incidence of surgical site infections.
has not been studied in prospective trials.
should be done by wet shaving 2 days before operation.
should not involve depilatory creams.
Answer:
The STOP-IT trial showed no untoward adverse events with
the intervention arm. Rate of recurrent infection, surgical
site infection, and length of stay were no different. In
subsequent subgroup analysis, there was no difference for
those with complicated intra-abdominal infection. Further,
neither diabetes nor obesity led to poorer outcome in the
intervention arm.
B
Antibiotics are important in the control of sepsis through the
event of source control. Once source control has occurred,
there is no proven benefit to antibiotic therapy beyond 4 days.
Thus, risk of resistance and complications of antibiotic use
can be limited. Further study is needed to determine whether
antibiotic duration of less than 4 days is appropriate.
The impact on surgical site infection (SSI) rates of removing
hair from operative sites remains unknown. Some—but not
all—retrospective studies suggest increased rates of SSIs
after hair removal. The Centers for Disease Control and
Prevention recommend against it, stating that hair should be
removed only when it will interfere with the operation,
preferably with electric clippers (not wet shaving) and
immediately before surgery. Clipping earlier than that is
generally not recommended. Some advisory bodies, such as
the Norwegian Center for Health Technologies Assessment,
advise that earlier hair removal should be done only with
depilatory creams. A recent controlled trial of more than 1500
patients randomized to hair removal or no hair removal
showed no difference in SSIs.
28. A 68-year-old man presents for surgical consultation for
sigmoid colon cancer. He has chronic obstructive pulmonary
disorder and hypertension, and he is an American Society of
Anesthesiologists class III risk. Which of the following
statements is true regarding prehabilitation for this patient?
A.
B.
C.
D.
There is a small increase in cardiac events.
Hospital length of stay is decreased.
Intensive care unit length of stay is decreased.
Inspiratory muscle training improves preoperative
pulmonary function.
E. Inspiratory muscle training reduces intraoperative
complications.
27. A 67-year-old man presents with 3 days of worsening left
lower quadrant pain. He has a known history of diverticulitis.
He has insulin-dependent diabetes and a BMI of 34. On
presentation, his white blood cell count is 13,500/mm3
(3600-11,200/mm3) and his temperature is 38.3°C. CT scan
of the abdomen shows a 5-cm simple pericolonic abscess. A
CT-guided percutaneous drain is appropriately placed. How
long should broad-spectrum antibiotics be administered after
source control?
A.
B.
C.
D.
E.
Answer:
Interest in the use of prehabilitation to reduce postoperative
complications in the elderly is increasing. Unfortunately, data
on the topic are limited. Prehabilitation is more than incentive
spirometry, smoking cessation, and routine ambulation. It
includes inspiratory muscle training, exercises specifically
focused on strengthening inspiratory muscles, and aerobic
exercise. Current evidence suggests that postoperative
complications are reduced with structured prehabilitation, but
there is no effect on intraoperative complications. Concern
has been raised that the effort required for prehabilitation
might increase the risk of a cardiac event with this
intervention, but this is not the case. The specific benefit to
prehabilitation is unknown because there are no measurable
preoperative pulmonary assessments. Intensive care unit
length of stay is reduced, but not hospital length of stay.
Antibiotics are not needed.
24 hours
4 days
7 days
14 days
Answer:
C
C
The STOP-IT trial was an open-label, randomized
prospective trial that compared limited duration antibiotics
for intra-abdominal infection with adequate source control
to antibiotic continuance until resolution of systemic
inflammatory response syndrome abnormalities (SIRS).
Patients were randomized to an intervention arm with
infectious source control followed by 4 days of appropriate
antibiotic therapy or resolution of SIRS abnormalities,
defined as a temperature lower than 38°C for 1 day, white
blood cell count less than 11,000/mm3, and the ability to
consume at least half of a regular diet without adverse
effect. Appendiceal disease was allowed as only a limited
component of the study.
16
29. A 67-year-old woman presents with clinical T2, Nl, MO
sigmoid colon cancer. She is scheduled for a laparoscopic
sigmoid colectomy. She is placed into an enhanced recovery
after surgery protocol. As part of this protocol, she is given
100 g of an oral carbohydrate load in 800 mL of liquid 2 hours
before surgery. Preoperative oral carbohydrate loading will
A.
B.
C.
D.
E.
transfusion in the clopidogrel group but no higher risk of
perioperative complications.
One study showed a higher rate of cardiac complications in
the group not on clopidogrel. This finding challenges the
notion of current standard practice. Continuance of
clopidogrel through the perioperative period appears safe for
most general surgical operations, including colectomy. Then?
is no need to hold clopidogrel preoperatively, and there is no
need to administer platelets intraoperatively.
reduce the risk of infectious complications.
induce hyperglycemia.
enhance gastric emptying.
reduce insulin resistance.
stimulate feelings of hunger.
Answer:
D
Enhanced recovery after surgery protocols are pre-, intra-,
and postoperative bundles of care intended to improve
surgical outcomes. One component of the preoperative
bundle is oral carbohydrate loading. Traditional fasting
before surgery leads to depletion of glycogen stores in the
liver, insulin resistance, and gluconeogenesis. Multiple
studies examined the potential benefit of shorter durations of
nothing by mouth preoperatively and the potential benefits of
carbohydrate loading. The primary benefit of carbohydrate
loading is a reduction in insulin resistance caused by the
surgical procedure and postoperative starvation. Perceived
benefits to patients are that they are less likely to be thirsty,
hungry, or anxious. There is neither a reduction nor increase
in risk of infection. Gastric emptying is not affected, and
patients do not become hyperglycemic.
30. A 72-year-old woman presents with a cecal cancer found
on screening colonoscopy. She takes clopidogrel for a
previous stroke. What is the appropriate perioperative
management of her anticoagulation in anticipation of a
laparoscopic right hemicolectomy?
A.
B.
C.
D.
Hold clopidogrel for 10 days preoperatively
Hold clopidogrel for 5 days preoperatively
Hold clopidogrel for 5 days and begin enoxaparin
Continue clopidogrel and administer platelets
intraoperatively
E. Continue clopidogrel without interruption
Answer:
E
The manufacturer of clopidogrel recommends holding the
drug for 5 days before major surgery. Given that the half-life
of platelets is 7 to 8 days, this recommendation seems
appropriate. However, there are increasing data in the safe use
of clopidogrel through the perioperative period. Elective
vascular surgery is routinely done with patients on
clopidogrel and aspirin. Two recent studies addressed the use
of clopidogrel in both elective and urgent general surgical
procedures. In both studies, there was a slightly higher rate of
17
Perioperative Care Part II
Items 5-10
Each lettered response may be selected once, more than once,
or not at all.
ITEMS 1-30
For each question, select the best possible response.
Items 1-4
Each lettered response may be selected once, more than once,
or not at all.
A.
B.
C.
D.
E.
A.
B.
C.
D.
E.
Apixaban
Dabigatran
Argatroban
Rivaroxaban
Idarucizumab
Cefoxitin
Cefazolin
Cefepime
No antibiotics
Vancomycin
5. Prophylactic antibiotic for a fundoplication in a high-risk
patient
6. Prophylactic antibiotic for a hernia repair
1. Parenteral direct thrombin inhibitor
2. Oral direct thrombin inhibitor metabolized by the kidneys
7. Prophylactic antibiotic for a laparoscopic, low-risk,
elective biliary tract procedure
3. Direct Factor Xa inhibitor recommended for patients with
low creatinine clearance
8. Prophylactic antibiotic for a laparoscopic or open
uncomplicated appendectomy
4. Oral Factor Xa inhibitor to avoid in patients with a low
creatinine clearance
9. Prophylactic antibiotic for a noncardiac thoracic procedure
10.
Prophylactic
antibiotic
ventriculoperitoneal shunt insertion
ANSWERS:
for
an
elective
C, B, A, D
Direct thrombin inhibitors (DTIs) and Direct Factor Xa
inhibitors are newer medications available to prevent and
treat thromboembolic disease. Examples of parenteral direct
thrombin inhibitors include bivalirudin, argatroban, and
desirudin. The only available oral direct thrombin inhibitor is
dabigatran. There are no parenteral Factor Xa inhibitors.
Examples of oral Factor Xa inhibitors include rivaroxaban,
apixaban, edoxaban, and betrixaban. Note that all of the
medications in this category end in "-xaban."
ANSWER:
Antimicrobial prophylaxis may be beneficial in cleancontaminated or contaminated surgical procedures associated
with a high rate of infection. Clinical practice guidelines for
antimicrobial prophylaxis and surgery were developed using
evidence-based methodologies to develop a standardized
approach to the rational, safe, and effective use of
antimicrobial agents to prevent surgical site infections (SSIs).
The guidelines provide many recommendations appropriate
for both adults and children. Additional recommendations
include weight-based dosing in obese patients, and the need
for repeat dosing when procedures exceed the half-life of the
antibiotic used. The optimal time for administering a
preoperative dose is within 60 minutes before the incision is
made.
Dabigatran is an oral direct thrombin inhibitor that should be
used with caution in patients with renal insufficiency because
it is metabolized by the kidneys. Rivaroxaban is a Factor Xa
inhibitor that is also metabolized by the kidney and is not
recommended for patients with low glomerular filtration rates
(creatinine clearance <30 mL/minute; 88-137 mL/minute).
Apixaban is a Factor Xa inhibitor that can be given to patients
with renal insufficiency because it has hepatic clearance.
Idarudzumab is a monoclonal antibody that binds dabigatran,
effectively reversing its anticoagulate activity.
Direct Thrombin Inhibitor
Factor Xa Inhibitor
Parenteral
Argatroban
Bivalirudin
Desirudin
Parenteral
NONE
Oral
Dabigatran
B, B, D, A, B, B
The principles of using an antimicrobial agent for surgical
prophylaxis include effectiveness against expected bacterial
pathogens, appropriate dose to ensure adequate serum levels
during wound contamination, short duration (usually 24
hours or less), low toxicity profile, proven ability to reduce
morbidity and mortality of a SSI, cost effectiveness, and a
low risk of adverse effects. Agents that are approved by the
US Food and Drug Administration for use in surgical
antimicrobial prophylaxis include cefazolin, cefuroxime,
cefoxitin, cefotetan, ertapenem, and vancomycin.
Vancomycin is an alternative agent in patients with a betalactam allergy. For patients known to be colonized with
methicillin-resistant Staphylococcus aureus, a single
preoperative dose of vancomycin can be added to the
recommended agent(s). Cefepime is not recommended for
perioperative prophylaxis.
Oral
Rivaroxaban
Apixaban
Edoxaban
Betrixaban
Current as of December 2018.
Table 1-4.1. Direct thrombin inhibitors (DTIs) and Direct
Factor Xa inhibitors are newer medications available to
prevent and treat thromboembolic disease.
19
A clean case is defined as one with no inflammation and no
entry into the respiratory, alimentary, genital, or uninfected
urinary tract. Fundoplication and hernia repair are both
considered clean cases. The stomach is an effective barrier to
bacterial colonization, partially related to its acidity.
Treatment with agents that increase gastric pH are associated
with an increase in the concentration of gastric organisms and
the potential to increase postoperative infection rate.
Prophylaxis for procedures without entry into the
gastrointestinal tract is indicated for only high-risk patients,
and cefazolin is an appropriate agent. Examples of high-risk
patients include those with achlorhydria, morbid obesity, or
cancer.
E. Hold anticoagulation for 5 days before the procedure
with heparin bridge; restart anticoagulation 48 hours
after the procedure; continue heparin for 5 days after the
procedure.
ANSWER:
C
Direct oral anticoagulation (DOAC) use is increasing.
Previously known as novel oral anticoagulation, DOAC is
noted for rapid onset of action and predictable effect on the
coagulation system without the need for monitoring. Many
patients who use DOAC will require surgery and it is
important to understand these drugs' pharmacokinetics,
indications for use, and paths of elimination.
Antimicrobial prophylaxis may be beneficial in clean surgical
procedures associated with a high risk of infection, such as
prosthetic implants, heart valves, or ventriculoperitoneal
shunt insertion, where the consequences of infection would
be devastating, even if the risk of infection is extremely low.
Cefazolin is appropriate prophylaxis for these cases.
DOAC have predictable pharmacokinetics. Dabigatran has a
half-life of 12 to 17 hours. Rivaroxaban has a half-life of 6 to
9 hours, and apixaban has a half-life of 12 hours. Half-life is
increased in patients with decreased creatinine clearance. For
surgery, DOAC is held for 2 to 3 half-lives for minor surgery
and 4 to 5 half-lives for major surgery.
Antimicrobial prophylaxis is warranted for most cleancontaminated procedures. The definition of a cleancontaminated wound allows the respiratory, alimentary, or
genitourinary tract to be entered under controlled
circumstances. Operations involving the biliary tract and
appendix are included in this category. Elective, low-risk
laparoscopic biliary tract procedures do not require
prophylaxis, but open or elective, high-risk procedures do
require prophylaxis. The biliary tract is usually sterile, and
antimicrobial prophylaxis confers no benefit. All patients
with a suspected biliary tract infection should receive
preoperative antimicrobial prophylaxis.
CHADS2 scoring is used to decide which patients with atrial
fibrillation need to have bridging of their therapy. The
CHADS2 score is calculated by adding up points from the
presence of congestive heart failure, hypertension, age older
than 75 years, diabetes mellitus, and history of stroke or
transient ischemic attack. A CHADS2 score of greater than 2
requires bridging.
In the scenario presented, the patient has a CHADS2 score of
1 based on hypertension. Thus, he will not need bridging. His
creatinine clearance is normal. He is having major surgery.
Thus, his apixaban should be held for 4 to 5 half-lives or 2
days before the procedure.
Cefoxitin is a recommended agent for prophylaxis in
uncomplicated appendicitis. If selected, cefazolin should be
combined with metronidazole. The typical organisms
reported from surgical site infections in patients undergoing
thoracic procedures are Staphylococcus aureus and
Staphylococcus epidermidis. Cefazolin is commonly used
with SSI rates of 0.42 to 4% compared with up to 14% when
no prophylaxis is used.
It is safe, barring any perioperative bleeding, to restart
anticoagulation 24 hours after a major procedure.
12.
A 57-year-old woman was diagnosed with
adenocarcinoma of the right colon and is scheduled to
undergo a laparoscopic right hemicolectomy. She currently
takes 5 mg of prednisone each morning for rheumatoid
arthritis. Appropriate perioperative management of her
steroids would be
11. A 72-year-old man presents with rectal cancer and is
scheduled for an open low anterior resection. He is on
apixaban for atrial fibrillation. His only other medical issue is
hypertension. What is appropriate management of his
anticoagulation around the procedure?
A. hold prednisone the day before surgery, then restart the
day of surgery.
B. continue prednisone at her normal dose perioperatively.
C. increase prednisone to 10 mg/day for 5 days after
surgery.
D. give 100 mg of hydrocortisone the day of surgery, then
restart normal prednisone dose.
A. Continue anticoagulation through the procedure.
B. Hold anticoagulation 24 hours before the procedure;
restart anticoagulation the evening of the procedure.
C. Hold anticoagulation 48 hours before the procedure;
restart anticoagulation 24 hours after the procedure.
D. Hold anticoagulation for 5 days before the procedure; do
not bridge with heparin; restart anticoagulation 24 hours
after the procedure.
20
E. give 100 mg of hydrocortisone the day of surgery, then
50 mg intravenously every 8 hours for 3 days after, then
restart normal prednisone.
ANSWER:
important in the synthesis and cross-linking of collagen. Zinc
is involved in the enzymatic activity of RNA and DNA
synthesis and collagenase function, and deficiencies can lead
to delays in epithelialization. If the vitamin and mineral stores
in a patient are questionable, such as in a gastric bypass
patient, the patient can be started on a multivitamin
supplement.
B
Chronic glucocorticosteroid administration can affect the
hypothalamic-pituitary-adrenal axis, leading to adrenal
atrophy and a decreased capability to produce cortisol. This
decreased production of cortisol during stress can lead to
hypotension. The question is what amount of cortisol is
needed during surgery to avoid this complication.
Optimizing glucose control has an impact on wound healing
and wound infection. Increased glucose levels, as measured
by hemoglobin A1C, lead to decreased neutrophil function.
This leads to a delay in the inflammatory response and
disrupts the timing of the wound-healing cycle. Impaired
neutrophil function can also lead to infection. Although
diabetic patients can have worse microvascular disease, no
change is noted in skin blood flow with improved glucose
control.
A patient with normal adrenal glands will produce
approximately 10 to 15 mg of cortisol/day. Under extreme
physiologic stress, the adrenals produce 300 mg/day. This
number drove the initial dosing recommendation of "stress
dose steroids," with 100 mg of hydrocortisone being
administered 3 times a day to any patient who was on even a
small dose of steroids.
Smoking causes microvascular vasoconstriction. This can
affect blood flow to the wound. Patients who are active
smokers have an increase in wound infection rates in addition
to an increase in skin or muscle flap necrosis. If a patient quits
smoking before surgery, blood flow increases. This increase
in blood flow leads to a decrease in wound infection rate and
skin flap necrosis.
Patients who undergo laparotomy secrete an average of 50 mg
of cortisol. This amount may be lower in laparoscopy.
Recent studies showed that patients undergoing surgery do
not need stress dose steroids. The patient should be able to
continue on her maintenance dosing schedule. Appropriate
conversion to intravenous dosage may be required. In the
scenario given, there is no indication to increase the amount
of steroids the patient is receiving. There is also no indication
to decrease the amount of steroids a patient is receiving if the
dose is adequately managing the condition for which the
patient is taking steroids.
Although hyperbaric oxygen is used to improve healing, there
is no evidence that preoperative hyperbaric oxygen is of use
in preventing wound complications. There is also no evidence
that a high-protein diet affects wound healing if initiated
before surgery.
Items 14-17
Each lettered response may be selected once, more than once,
or not at all.
13. A 62-year-old man with a complex abdominal wall hernia
is scheduled to undergo an abdominal wall reconstruction that
will require skin flaps for skin closure. What will decrease his
incidence of skin flap necrosis?
A.
B.
C.
D.
E.
A.
B.
C.
D.
E.
Preoperative hyperbaric oxygen
High-protein diet
Zinc supplementation
Smoking cessation
Glucose control optimization
No evidence exists
Evidence exists but is inconclusive
Evidence exists and favors use
Evidence exists and does not favor use
Level I evidence
14. Cleansing of the operation site with chlorhexidinealcohol.
15. Wearing surgical scrubs.
16. Covering the wound with a dressing.
ANSWER:
D
17. Disinfecting the intravenous catheter hub.
The process of wound healing is a combination of patient
factors, wound factors, and surgical technique. All point to
the same aspects of wound healing: tissue blood flow,
bacteria, proper tissue handling, and immunologic response.
ANSWER:
C, B, B, E
Surgical site infection is the second most common healthcareassociated infection (after respiratory infection) and results in
a significant increase in healthcare costs. Guidelines were
developed to reduce the incidence of surgical site infection,
but many of these guidelines lack evidence or consensus.
In the preoperative period, patients can improve the chance
that their wounds will heal successfully. With regard to
wound healing, the patient needs adequate stores of woundrelated vitamins and minerals. Vitamins A and C are
21
Evidence-based medicine uses the best available evidence to
make clinical decisions. Levels of evidence reflect the quality
of the existing studies and supportive data. Level I evidence
is generally based on randomized controlled trials and the
highest quality of evidence with little doubt as to
effectiveness. For example, the use of antimicrobial
prophylaxis in dean-contaminated and contaminated surgical
cases within 60 minutes of incision time is supported by good
evidence and is embraced by most surgeons. Similarly, "scrub
the hub" or intravenous catheter hub disinfection before
injection has good evidence to support it, including
randomized controlled clinical trials involving multiple
operating rooms.
recommendation is to minimize the number of staff turnovers,
which is an independent variable associated with increased
surgical site infections.
A recent review of the last decade of published literature
evaluating alternatives to antibiotics in the prevention of
surgical site infection highlighted perioperative practices.
Tissue adhesives are easier and quicker to use than suturing a
wound dosed. Although there seems to be no significant
difference in rates of surgical site infection between the 2
wound closure techniques, more wound dehiscence tends to
occur with tissue adhesives. A high oxygen tension seems to
be important for wound healing and increases the activity of
neutrophils in tissues, which may be important for resisting
infection. However, randomized controlled trials and a metaanalysis examining high perioperative oxygen concentrations
were contradictory for prevention of surgical site infections
across all surgical procedures. A survey study through the
Americas Hernia Society Quality Collaborative examining
6210 hernia repairs done by 68 surgeons and evaluating 6
different types of disposable or cloth operating room hats
found no difference in the incidence of surgical site infection
occurrences based on hat type. A more recent study suggested
that cloth skull caps are associated with less risk of surgical
site infection than disposable caps. Several papers and a
meta-analysis including 17,000 patients suggested that
preadmission showering with an antiseptic agent is
inconclusive for the prevention of surgical site infection.
Some practices, such as wearing surgical attire in the
operating room, have little or no supportive evidence through
clinical trials but are guided by the concepts of Pasteur,
common sense, and conventional wisdom. There are no
published studies evaluating the efficacy of wearing surgical
gowns. There is little evidence that wearing surgical scrubs
contributes to a reduction in surgical site infection. Wearing
sterile surgical gloves is accepted practice but not of proven
benefit. It is doubtful that a randomized controlled trial will
ever be done comparing street attire to surgical attire in the
operating room.
Other practices, such as the choice of agent used to cleanse
the operative site before incision and wound coverage after
completion of a surgical case, have been studied, and
evidence favors certain practices. Results of a meta-analysis
and Cochrane review both favored chlorhexidine-alcohol
over aqueous povidone-iodine in general surgery cases. More
recent studies showed no difference, but interpretation was
hampered because variable antiseptics and concentrations
were used. There is no compelling evidence that protection of
a surgical wound with a dressing after case completion is of
significant benefit. Although some guidelines recommend
covering the surgical wound with a dressing for the first 48
hours after surgery, this recommendation is not supported by
current literature. Surgical site infection rate is reported to be
the same when the wound is left uncovered, is covered for 48
hours, or is covered for less than 48 hours.
19. A 73-year-old woman with a history of chronic
nonvalvular atrial fibrillation treated with dabigatran is
diagnosed with a 3-cm bleeding gastric adenocarcinoma. Her
medical history includes noninsulin-dependent diabetes
mellitus. She wishes to undergo partial gastrectomy for her
cancer. Which of the following recommendations should you
make?
A. Convert from dabigatran to rivaroxaban preoperatively
B. Convert to therapeutic heparin bridging anticoagulation
before surgery
C. Stop dabigatran 2 days before surgery
D. Continue dabigatran
E. Convert to warfarin before surgery
18. During a single surgical case, which of the following
interventions decreases surgical site infection?
A.
B.
C.
D.
E.
Decreased operating room personnel turnover
Wound closure with tissue adhesive versus sutures
Use of high FiO2 intraoperatively
Disposable bouffant hats
Preoperative chlorhexidine bathing
ANSWER:
ANSWER:
C
International guidelines exist for the use of long-term
prophylaxis to prevent stroke in patients with atrial
fibrillation. When dabigatran therapy needs to be interrupted
for surgical procedures, there is no need to bridge the patient
with heparin due to the rapid offset (half-life: 12-17 hours)
and rapid onset (tmax 1-3 hours) of the action of dabigatran.
Stopping and starting dabigatran therapy would only result in
a 2- to 4-day period when patients would be subtherapeutic
regarding anticoagulation.
A
Many guidelines exist for the perioperative care of surgical
patients. There is variable evidence to either support or not
support the interventions listed here. The best evidence exists
around traffic in the operating room during a case. The
22
In a study of 1200 patients who underwent noncardiac
surgery, 6.7% experienced a primary outcome of AKI. Age,
diabetes mellitus, hypertension, and American Society of
Anesthesiologists status were independent predictors of AKI.
Atrial fibrillation, heart failure, female sex, and anemia were
not risk factors.
In the RE-LY trial, more than 4000 patients who were on
dabigatran or warfarin had their anticoagulation therapy
interrupted around the time of an elective surgery or
procedure. Patients in this study who were bridged with
heparin had significantly more major bleeds than those who
were not bridged (6.5% vs 1.8%; p <.001). The risk for stroke
and systemic embolism was not different in patients who
were bridged versus not bridged (0.5% vs 0.3%). Somewhat
surprisingly, the thromboembolism risk was higher in
patients who received bridge therapy with heparin (1.2% vs
0.6%), but this difference was not statistically significant.
There are no demonstrable differences between dabigatran,
rivaroxaban, or apixaban with respect to the risk of stroke or
systemic embolism. Apixaban is associated with a lower risk
of major bleeding compared with the other 2 agents, whereas
rivaroxaban is associated with an increased risk of major
bleeding and intracranial bleeding compared with dabigatran.
Continuing these agents through major surgery or switching
dabigatran to rivaroxaban is associated with increased risk of
major bleeding. For the same reason, there is no justification
for switching from a direct oral anticoagulant to warfarin, a
Vitamin K antagonist that has a longer half-life.
Procedure-related factors were associated with developing
AKI. Reoperation had a 5-fold increased risk, and emergency
surgery had a 1.5-fold increased risk. Perioperative AKI was
associated with a 3- to 4-fold increased risk of cardiovascular
adverse events and in-hospital mortality. Patients who
reached their peak serum creatinine value more than 2 days
after surgery had a comparable 30-day mortality with those
patients who had their peak serum creatinine within the first
2 postoperative days. There was a dose-response relationship
between mortality and severity, with a 30-day mortality of
12.3%, 19.1%, and 43.2% for AKI stages 1,2, and 3 groups,
respectively.
Elevated C-reactive protein is also associated with AKI.
Although ensuring adequate hydration and hemodynamic
status perioperatively may reduce the risk of perioperative
AKI, no data show that postoperative hydration will improve
a patient's survival. In a meta-analysis exploring the impact
of sodium bicarbonate infusion on patients with AKI, the
authors were unable to demonstrate an impact on mortality
risk for patients receiving bicarbonate infusion.
20. A 72-year-old woman undergoes sigmoid resection for
carcinoma. Her medical history is significant for ratecontrolled atrial fibrillation. On postoperative day 1, the
patient's urine output is 0.5 mL/kg/hour while her serum
creatinine doubles. Which of the following statements about
her 30-day mortality risk is true based on her change in renal
function?
21. A 42-year-old woman presents on postoperative day 5
after an extensive lysis of adhesions. She continues to have
high bilious nasogastric tube drainage, and her abdomen
remains distended, mildly tender, with no bowel sounds or
evidence of peritonitis. Her vital signs and urine output are
normal. Laboratory data are as follows: white blood cell
count = 9800/mm3 (3600-11,200/mm3), hematocrit + 42%
(37-51%), sodium = 146 mEq/L (136-145 mEq/L), potassium
= 3.1 mEq/L (3.5 5.0 mEq/L), bicarbonate = 24 mmol/L (2029 mmol/L), chloride = 98 mEq/L (95-105 mEq/L). The next
step in the management of her ileus is
A. The severity of her acute kidney injury correlates with
her mortality risk. B Acute kidney injury within the first
day after surgery increases her mortality risk.
B. Postoperative hydration will improve her survival.
C. Sodium bicarbonate infusion will lower her mortality
risk.
D. Decreased C-reactive protein levels are associated with
increased risk.
ANSWER:
A.
B.
C.
D.
E.
A
In patients undergoing surgery, perioperative acute renal
failure is a leading cause of morbidity and mortality, with an
incidence of up to 30% of patients. A collaborative network
of international experts addressed the lack of a universal
definition for acute kidney injury (AKI) by establishing the
Acute Dialysis Quality Initiative and devised the RIFLE (risk,
injury, failure, loss of function, and end-stage kidney disease)
definition and staging system.
metoclopramide.
potassium chloride.
erythromycin.
neostigmine.
alvimopan.
ANSWER:
B
Postoperative ileus is a common condition after abdominal
and other types of surgery. The pathogenesis of this
complication is complex and involves stress-induced release
of catecholamines and cytokines that inhibit colonic motility.
Ileus may also be exacerbated by anticholinergic
medications, opioids, and general anesthetics, as well as fluid
and electrolyte abnormalities.
AKI is classified into stages based on the degree of increase
in serum creatinine.
23
Hypokalemia, frequently accompanied by hypomagnesemia,
is a significant contributing factor. Potassium facilitates
depolarization of smooth muscle cell membranes, causing
calcium channels to open such that extracellular calcium
enters the cell, triggering smooth muscle contraction. In a
patient with a postoperative ileus and hypokalemia,
correction with potassium chloride frequently decreases the
duration of the ileus. For the ileus to be effectively treated,
serum magnesium must be normal.
In the postoperative period, an important concern is the
optimal dosing of replacement therapy. Measurement of a
platelet count is insufficient because platelet count provides
no information as to platelet activity. Factor VII and
fibrinogen are not directly related to Von Willebrand disease.
Von Willebrand activity level is determined by ristocetin
cofactor activity, which tests the ability of vWF to clump by
binding to its primary receptor, platelet glycoprotein Ib; it is
an indirect measure of platelet activity. Therefore, monitoring
of Factor VIII activity is the superior method for monitoring
a patient with Von Willebrand disease in the postoperative
period.
Metoclopramide accelerates gastric emptying and stimulates
gastric, pyloric, and small intestine motility but has no effect
in the colon. Metoclopramide does not shorten the duration
of postoperative ileus. Erythromycin acts on motilin receptors
that stimulate smooth muscle contraction. Erythromycin
lacks activity in the colon and does not decrease the duration
of ileus. Neostigmine is an anticholinesterase that inhibits the
hydrolysis of acetylcholine. This action is not selective for
muscarinic receptors, which mediate gastrointestinal
motility. Although neostigmine causes muscle fasciculations,
it does not improve the course of postoperative ileus.
Thromboelastography (TEG) is a viscoelastic method used to
measure coagulation function. Because of the lack of shear
stress essential for the activation of vWF, the standard TEG
assay was not thought to be of use in von Willebrand disease.
A modified TEG using ristocetin activation is under
investigation in the monitoring of patients with von
Willebrand disease.
Alvimopan is an oral peripherally acting mu-opioid receptor
antagonist that appears to hasten postoperative
gastrointestinal recovery after bowel surgery and abdominal
hysterectomy. Although it appears to accelerate motility and
decreases the duration of ileus, it must be started
preoperatively.
23. A 52-year-old man who is heparin naive is started on
subcutaneous unfractionated heparin (UFH) for postoperative
deep venous thromboembolism prophylaxis. The next day,
his platelet count falls from 260,000/mm3 to 102,000/ mm3
(150,000-400,000/mm3). Management of his deep vein
thrombosis prophylaxis should entail which of the following?
A. Discontinue UFH and start low molecular weight
heparin.
B. Continue UFH.
C. Discontinue UFH and start fondaparinux.
D. Discontinue UFH.
E. Discontinue heparin and start argatroban.
22.
Which of the following should be monitored
postoperatively in a patient with von Willebrand disease who
has undergone an elective abdominal operation?
A.
B.
C.
D.
E.
Platelet count
Fibrinogen level
Von Willebrand Factor activity
Thromboelastography
Factor VIII activity
ANSWER:
ANSWER:
B
Using
heparin
to
prevent
deep
venous
thromboembolism/pulmonary embolism is common in the
postoperative
period.
However,
heparin-induced
thrombocytopenia (HIT) is a significant complication, with
potential for morbidity and mortality. Pharmaceutical heparin
can be unfractionated (UFH), which consists of a
heterogenous mixture of sulfated polysaccharides (MW:
8,000-24,000 Da), or low-molecular weight heparin
(LMWH) with molecular weight between 2,000-8,000 Da.
E
Von Willebrand disease is the most common inherited
bleeding disorder. It affects up to 1% of the population. Von
Willebrand Factor (vWF) plays a fundamental role in
bleeding control by connecting platelets and subendothelial
structures at the site of blood vessel injury, thus leading to
primary hemostasis. vWF is also a carrier protein for Factor
VIII, thereby assisting in clot formation after the platelet plug
has been formed.
There are 2 distinct types of HIT. This patient has HIT type
I. Type I or heparin-associated thrombocytopenia is a
nonimmunologic response to heparin treatment, mediated by
a direct interaction between heparin and circulating platelets
causing platelet clumping or sequestration. HIT type I affects
up to 10% of patients, usually occurs within the first 48 to 72
hours after initiation of heparin treatment, and is
characterized by a mild and transient thrombocytopenia
(rarely <100,000/mm’), often returning to normal. No
Patients with von Willebrand disease report a history of easy
skin and mucosal bleeding, epistaxis, easy bruising, and
menorrhagia. Preoperative evaluation consists of measuring
Factor VIII activity, von Willebrand activity, and ristocetin
cofactor activity. Desmopressin or a concentrate of vWF and
Factor VIII is used for surgical prophylaxis.
24
laboratory tests are required to diagnose HIT type I, and it is
not associated with an increased risk of thrombosis.
Therefore, continuation of the UFH is appropriate.
Multiple immunological assays can be used to confirm the
diagnosis of HIT type IIincluding platelet function tests,
platelet
aggregation
studies,
flow
cytometry,
antiheparin/platelet Factor 4 titers, and enzyme-linked
immunosorbent assay to detect antibodies to heparin/platelet
Factor 4 complex. These studies not only require a prolonged
period of time for results to return but also have many false
positives and negatives. As a result, the laboratory testing
should be used only in conjunction with the clinical context.
Conversely, HIT type 2, is a drug-mediated, prothrombotic
condition caused by IgG antibody production against platelet
Factor 4. This immunologic interaction is capable of
intravascular platelet activation and devastating life- or limbthreatening thrombosis by white dot or dot composed
primarily of platelets. HIT type II typically occurs 4 to 5 days
after starting UFH or LMWH or after a shorter period if the
patient has been previously exposed to heparin.
Points (0,1, or 2 for each of 4 categories: maximum possible score = 8)
2
>50% platelet fall to nadir≥20
1
30-50% platelet count fall (or
>50% directly resulting from
surgery); or nadir 10-19
0
<30% platelet fail; or
nadir<10
Timinga of platelet count
fall, thrombosis, or other
sequelae (1st day of
putative immunizing
exposure to heparin = day
0)
Days 5-10 onseta (typical/
delayed onset HIT); or ≤ 1 day
(with recent heparin exposure)
or within 30 days (rapid-onset
HIT)
Platelet count fail <4
days (unless picture of
rapid-onset HIT)
Thrombosis or other
sequelae (e.g., skin
lesions, anaphylactoid
reactions)
Proven new thrombosis; or
skin necrosis (at injection
site); or postintervention
heparin bolus anaphylactoid
reaction
No explanation for platelet
count fail is evident
Consistent with days 5-10 fall,
but not clear (e.g., missing
platelet counts); or ≤ 1 day
(heparin exposure within the
past 31-100 days) (rapid-onset
HIT); or platelet fall after day
10
Progressive or recurrent
thrombosis; or erythematous
skin lesions (at injection site);
or suspected thrombosis (not
proven); hemofilter thrombosis
Possible other cause is evident
Thrombocytopenia
Other cause for
thrombocytopenia
None
Definite other cause is
present
Pretest probability score: 6-8 = high; 4-5 = intermediate; 0-3 = low
HIT = heparin-induced thrombocytopenia.
a
First day of immunizing heparin exposure considered day 0; the day the platelet count begins to fall Is considered the day of
onset of thrombocytopenia (It generally takes 1-3 more days until an arbitrary threshold that defines thrombocytopenia is
passed). Usually, heparin administered at or near surgery is the most immunizing situation (i.e., day 0).
*
Table 23.1. The 4Ts scoring system.
The 4 Ts Score (table 23.1) is calculated based on the degree
of thrombocytopenia, timing, evidence of thrombosis, and
potential alternative causes. If the score is 0 to 3, type II HIT
is low probability, with a negative predictive value of 0.998.
A score of 4 to 5 points indicates intermediate probability,
with a positive predictive value of 0.14. A score of 6 to 8 has
a high probability of type II HIT, with a positive predictive
value of 0.64.
24. Which of the following statements is true regarding
opioid prescriptions after general surgical operations?
A. Variability in the prescriptions of opioids after discharge
is limited.
B. The majority of prescribed opioids are consumed after
surgery.
C. Educational interventions for surgeons decrease opioid
prescribing.
D. Most patients after general surgical procedures require
refills of their narcotics.
E. Preoperative opioid use is not associated with higher
readmission rates.
If there is concern about type II HIT, all heparin products
should be stopped, and the patient should be started on
activated Factor X inhibitors such as danaparoid or
fondaparinux. Alternatively, the patient can be started on
direct thrombin inhibitors such as argatroban or bivalirudin.
25
ANSWER:
symptoms. Which of the following should be included in his
preoperative evaluation?
C
The opioid epidemic is partly attributed to prescription
opiates commonly prescribed after surgery. The prescription
of opioids after surgery varies widely across all procedures.
However, in a study of 642 patients, less than 28% of
prescribed pills were taken and less than 2% of refills were
obtained. Educational interventions to decrease opioid
prescriptions reduced prescriptions by 53% compared with
the number of prescriptions before the intervention. Opioid
naive surgical patients become prolonged opioid users at rates
2.6 to 3.6 times higher than patients who did not undergo
surgery. Patients who use opioids before abdominopelvic
surgery have 9.2% higher costs, longer lengths of stay, more
complications, and higher readmissions.
A.
B.
C.
D.
E.
ANSWER:
A
The preoperative assessment of a patient undergoing an
elective procedure should begin with a thorough history and
physical. The practice of routine laboratory, cardiac
evaluation, and radiologic evaluation is not recommended
without clear indication of risk for comorbidity. Current
recommendations for healthy, American Society of
Anesthesiologist (ASA) class I patients undergoing minor or
intermediate grade surgery is to not perform resting
electrocardiograms, complete blood counts, liver panels,
urinalysis, coagulation tests, or basic metabolic panels.
Asymptomatic men who are older than 45 years and women
who are older than 50 years should undergo
electrocardiogram. Routine chest x-ray is not recommended.
25. A 70-year-old man on rivaroxaban for chronic atrial
fibrillation (CHADS2 <5) is scheduled to undergo an open
umbilical hernia repair. What perioperative recommendation
is most appropriate?
A. Stop rivaroxaban 3 days before surgery, restart
rivaroxaban 5 days after surgery
B. Stop rivaroxaban on admission, bridge with heparin,
restart rivaroxaban 5 days after surgery
C. Continue rivaroxaban
D. Stop rivaroxaban 1 day before surgery, restart 6 hours
after the procedure
E. Stop rivaroxaban 3 days before, anticoagulate with
warfarin, restart rivaroxaban 3 days after surgery
ANSWER:
No laboratory studies
Complete blood count
Chest x-ray
Electrocardiogram
Basic metabolic panel
27. You are preparing to perform a right hepatectomy on a
65-year-old woman for colorectal metastasis. She has a
baseline iron deficiency anemia, and after 1 month of
preoperative iron supplementation, her hemoglobin is 10
g/dL (12-15.5 g/dL). The anesthesiologist asks if you want to
use red cell salvage techniques during the procedure.
Intraoperative red cell salvage
D
A. reduces transfusion-related immunomodulation.
B. has no role outside of cardiac surgery.
C. should not be used in cases of malignancy or bowel
surgery.
D. should be used only if intraoperative blood loss is
predicted to exceed 2 L.
E. requires full anticoagulation.
Rivaroxaban is a direct Factor Xa inhibitor and is a member
of the class of direct oral anticoagulant used to prevent and
treat thromboembolic events. The half-life of rivaroxaban is
5 to 9 hours in healthy patients and 11 to 13 hours in elderly
patients. The drug is usually metabolized 66% in the liver via
the CYP3A4 and CYP2J2 enzymes, and 33% is excreted
unchanged.
An umbilical hernia repair is considered a low bleeding risk
procedure in a patient who is at low risk of thromboembolic
events (CHADS2 <5). In such a situation, it is appropriate to
stop the drug 24 hours before surgery and to resume it 6 hours
after surgery. In extremely high-risk surgery, rivaroxaban
should be stopped at least 3 days before surgery. Barring
technical misadventures, it is appropriate to restart
rivaroxaban at least 6 hours after the procedure.
ANSWER:
A
Red cell salvage is a process whereby shed whole blood is
suctioned from the surgical field, collected in a reservoir, and
then prepared for red cell reinfusion. Although this practice
is most often used in cardiac surgery, other applications
include orthopaedic, vascular, and trauma surgery. Systemic
anticoagulation is not required, and in the process of
preparing the cells for reinfusion, heparin used in the salvage
process is removed. Each 200 mL unit of salvaged red cells
is equivalent to the red cell mass in a unit of packed red blood
cells. Because the cells are autologous, the risk of immunemediated transfusion reactions and complications, including
transfusion-associated acute lung injury and transfusion-
26. A44-year-old carpenter presents to clinic with complaints
of a symptomatic right inguinal hernia. His bowel and bladder
functions are normal. His medical history is positive for open
appendectomy and gastroesophageal reflux for which he
takes pantoprazole. He denies cardiac or pulmonary
26
associated immunomodulation, are avoided. It appears that
use of cell salvage reduces the risk of needing an allogenic
blood transfusion by 21%, and on average, it saves patients
0.68 units of transfused blood per procedure. Cell salvage
typically is reserved for procedures with an estimated blood
loss of at least 500 to 1000 mL. There is no evidence for
increased rates of infection or reinfusion of malignant cells
with cell salvage techniques. Because clotting factors and
platelets are removed from these salvaged cells, plasma and
platelet transfusions may still be necessary if significant
bleeding occurs.
procedures. Slightly more than one-third of patients did not
interrupt the apixaban.
29. A 65-year-old man is scheduled for an elective sigmoid
colectomy for diverticular disease. He has a history of
coronary artery disease and underwent placement of a drugeluting stent 1 year ago. He remains on aspirin and
clopidogrel. What is the optimal approach to his perioperative
aspirin and clopidogrel management?
A. Continue both clopidogrel and aspirin through surgery
B. Hold aspirin 1 week before surgery, continue clopidogrel
through surgery
C. Hold both clopidogrel and aspirin 1 week before surgery
D. Hold clopidogrel 1 week before surgery, continue aspirin
through surgery
E. Hold both clopidogrel and aspirin 1 week before surgery
with a heparin bridge
28. A 65-year-old man is scheduled for an elective sigmoid
colectomy for diverticular disease. He has a history of atrial
fibrillation with a CHA2DS2-VASc score of 4. He takes
rivaroxaban for stroke prevention. What is the optimal
approach to his preoperative rivaroxaban management?
A.
B.
C.
D.
E.
Continue rivaroxaban through the surgery
Hold rivaroxaban 1 week before surgery
Hold rivaroxaban 2 days before surgery
Hold rivaroxaban 4 days before surgery
Hold rivaroxaban on the morning of surgery
ANSWER:
ANSWER:
D
To mitigate the risk of stent thrombosis, dual antiplatelet
agents should be continued, and any elective surgery delayed
for a minimum of 1 year. Thereafter, the continued need for
dual antiplatelet therapy can be assessed using the dual
antiplatelet therapy score. For patients with a score of 2 or
greater, dual antiplatelet therapy is typically continued for 18
additional months or longer, although elective surgery can
safely proceed after 1 year.
C
The new oral anticoagulants are used routinely for stroke
prevention in patients with atrial fibrillation. Rivaroxaban is
an oral Factor Xa inhibitor with a half-life of between 8 and
10 hours (depending on patient age and comorbidities). It is
cleared both by urinary excretion of the active drug and by
metabolism to an inactive form. For major surgical
procedures, such as a sigmoid colectomy, the short-term risk
of a major bleeding complication is 2 to 4%, whereas a
CHA2DS2-VASc score of 4 gives this patient a 4.8% chance
of a thromboembolic complication over the next year
(0.01%/day). Consequently, rivaroxaban should be held.
Assuming this patient has normal creatinine clearance, the
patient should skip 2 doses (off anticoagulation for 48 hours)
before surgery. Bridge anticoagulation is not required in this
patient. Assuming he has normal return of bowel function and
no perioperative bleeding, he can resume rivaroxaban 2 to 3
days postoperatively.
For major surgery, such as a sigmoid colectomy, the risk of a
perioperative bleeding complication is 2 to 4%. In this patient
with coronary artery disease and a stent, his aspirin represents
secondary prevention and should be continued through the
procedure to mitigate the risk of a cardiac complication. It can
also help mitigate the risk of stent thrombosis in the early
postoperative period. Beyond 1 year after placement of a
drug-eluting stent, dopidogrel can be safely held for a brief
period around the time of surgery. It is generally held for 5 to
7 days preoperatively and resumed several days
postoperatively when the bleeding risk has subsided. In
patients at higher risk of stent thrombosis, a loading dose of
dopidogrel can be given on resumption of the medication.
For procedures with a low bleeding risk on a patient who is
also at a low risk of thromboembolic events, rivroxaban can
be stopped 24 hours before surgery and resumed 6 hours after
surgery or when the surgeon believes the risk of bleeding is
low.
In the ARISTOTLE trial, apixaban was used for patients with
a low risk of thromboembolic events and low bleeding risk
27
30. When closing a midline abdominal incision after an
elective procedure, what suture technique minimizes the rate
of incisional hernia development?
A. Continuous sutures with 1-cm bite depth and 1-cm
intersutural distance
B. Continuous sutures with 5-mm bite depth and 5-mm
intersutural distance
C. Interrupted sutures with 1-cm bite depth and 1-cm
intersutural distance
D. Interrupted sutures with 5-mm bite depth and 5-mm
intersutural distance
E. Interrupted retention sutures with 2-cm bite depth and 2cm intersutural distance
ANSWER:
B
Fascial dehiscence with or without evisceration carries a
significant morbidity and mortality. Failed surgical closures
result in incisional hernias (up to 21%), dehiscence (1-4%),
or evisceration, and these patients have a significantly
increased mortality— as high as 35%. Approximately
100,000 incisional hernia repairs are undertaken annually;
thus, addressing any modifiable risk factors for these
occurrences is warranted. The principal mechanism of wound
failure is sutures pulling through the fascia. Infection plays a
role in approximately 30% of cases, whereas inadequate
suture length and excess tension represents the primary factor
in more than 60% of cases. The optimal recommended suture
length to wound length ratio (SL: WL) is 4:1 (i.e., for a 15cm incision, use 60 cm of suture, not counting the discarded
tails). Suture breakage and knot failure are rare.
A continuous monofilament suture in a single layer of closely
placed bites pulled up with minimal tension substantially
reduces the risk of surgical incision failure. Small bites of 5
mm from the fascial edge and 5 mm from the last bite will
result in a SL:WL ratio of at least 4:1 if minimal tension is
applied when pulling up each suture (to the point where the
fascial edges are just touching). Bites further from the fascial
edge and spaced further apart lead to insufficient suture use;
thus, excess tension is placed on each bite with normal
physical activities. Interrupted sutures of any variety take
more time and result in less bursting strength than continuous
suture closures. In fact, meta-analyses demonstrate a
significantly greater risk of incisional hernia development
with interrupted suture closure of elective midline laparotomy
incisions. Finally, retention sutures are placed to theoretically
reduce the risk of evisceration after abdominal closure in
urgent cases, although their benefit has not been rigorously
evaluated. They have no known role in the primary closure of
elective surgical incisions.
28
Perioperative Care Part III
hemorrhagic stroke, undergoing high-risk surgical
procedures, or who have sustained severe trauma. In these
patients, inferior vena cava (IVC) filters can afford protection
from pulmonary embolism from lower extremity deep vein
thromboses (DVTs). Absolute indications for placement of
these filters are recurrent VTE despite adequate
anticoagulation, contraindication to anticoagulation,
complications resulting from anticoagulation, and inability to
maintain or achieve appropriate anticoagulation. Relative
indications include recurrent pulmonary embolism, freefloating lower extremity DVT, and iliocaval DVT.
Prophylactic IVC filters are the most common indication
(58%) for placement and can be used in trauma, surgical, or
medical patients at high risk for DVT. IVC filter placement is
most commonly performed via femoral vein approach.
Overall complications are low. Early (<30 days)
complications
(e.g.,
hematoma,
pseudoaneurysm,
oversedation) occur in 7%. Long-term complications include
recunent DVT (20%), stent migration (1.3%), and thrombosis
(2.8%). Long-term complications should be avoidable
because most IVC filters are removable. The current problem
is that only 35 to 40% of IVC filters are removed. It is
incumbent on all healthcare providers to be aware of this
problem and to make sure filters are removed as soon as
medically indicated.
ITEMS 1-30
For each question, select the best possible response.
1. For patients who are undergoing elective surgery and who
are chronically on statin therapy, which of the following
statements regarding risk is true?
A. Discontinuing statins perioperatively is associated with
increased stroke risk
B. The benefit of continuing statins is most pronounced in
those over age 75.
C. Continuing statins perioperatively is associated with an
increased rate of deep organ space infections.
D. Continuing statins perioperatively is associated with a
reduction in all-cause mortality.
E. Reduction in perioperative risk is primarily due to the
lipid lowering effects of statins.
ANSWER:
D
Perioperative HMG-CoA reductase inhibitors (statins) should
be continued perioperatively for patients using them
chronically. Statin continuation within 24 hours of elective
surgery decreases all-cause mortality, especially due to
cardiac events in patients undergoing noncardiac operations.
This effect is not solely due to the lipid-lowering effects of
statins; the anti-inflammatory properties appear to primarily
provide protection. Although the benefits of continuing
statins perioperatively are most marked in the reduction of
cardiac events, there are also observed decreases in
infectious-related complications, renal failure, and
respiratory complications. There is, however, no apparent
effect on central nervous system complications. Patients
younger than 75, patients with heart disease or diabetes, or
patients undergoing high-risk surgical procedures are at most
risk, and perioperative statins should be continued if possible.
3. A 53-year-old man undergoes a laparoscopic low anterior
resection with diverting loop ileostomy for a T2N0 rectal
cancer. On postoperative day 6, he develops a fever and
leukocytosis. Pelvic CT scan reveals a pelvic abscess, which
responds to percutaneous drainage. He improves clinically
and is seen in the office a week later. At that time, a drain
study confirms anastomotic leak at the coloproctostomy and
resolution of the abscess. His complete blood count and basic
metabolic panel are normal, and he has mild abdominal
tenderness at his incisions. He is tolerating a regular diet, and
drain output is 50 mL/day. What is the most appropriate
treatment?
A. Continued observation with diet as tolerated
B. Bowel rest and parenteral nutrition
C. Endoscopic injection of fibrin glue
D. Laparotomy with primary repair of the anastomotic
defect
E. Laparotomy, resection of the anastomosis, and end
colostomy
2. Which of the following statements is true regarding
management of inferior vena cava filter placement or
retrieval?
A. Early complication rates exceed 30%.
B. Venous thrombosis is the most common late
complication.
C. Most complications occur within 30 days of placement.
D. Therapeutic indications are more frequent than
prophylactic indications.
E. More than 50% of retrievable filters are being removed.
ANSWER:
ANSWER:
B
A
Low pelvic anastomoses for rectal cancer are associated with
anastomotic leak rates of 10 to 20%, with the number being
higher as the anastomosis gets lower in the pelvis. These leaks
can lead to severe pelvic sepsis and death. Even if the patient
survives the acute episode, there is an association with worse
long-term cancerspecific survival. Given these poor
outcomes, most surgeons routinely protect low pelvic
Venous thromboembolism (VTE) occurs in approximately
1:1000 general-risk and 1:100 high-risk patients and can
result in pulmonary embolism. Pulmonary embolism has a
mortality rate of 25%. Anticoagulation remains the most
common prophylactic and treatment method, yet it is
contraindicated in patients with recent hemorrhage,
30
anastomoses with, a loop ileostomy. Whether temporary
proximal diversion truly reduces leak rates or whether it
instead simply reduces the clinical impact of leaks, including
a less frequent need for surgical re-exploration, is
controversial.
Because of the technical skill required and the lack of distal
healthy bowel, low pelvic anastomotic repair and salvage is
quite difficult at the time of diagnosis. Unprotected
anastomoses that leak often require takedown and permanent
fecal diversion.
This patient had an anastomotic leak, but it was diverted
proximally. He is now clinically normal with no uncontrolled
sepsis after a percutaneous drain created a controlled
colocutaneous fistula. Most of these fistulas (-75%) will close
spontaneously over time and not require surgical
intervention, but they can take up to 6 months to heal. During
this time, observation and ongoing percutaneous drainage are
typically all that is necessary without a need for antibiotics or
bowel rest. The anastomosis is followed with serial watersoluble contrast enemas or CT scans with rectal contrast.
as HIT antibodies). Less than 5% of these patients go on to
develop the syndrome of heparin-induced thrombocytopenia
(HIT). Antibody formation is lower in patients treated with
low molecular weight heparin (LMWH, 8%), and the relative
risk of thrombotic complications is 0.22 compared with UFH.
Despite its rarity, HIT remains quite morbid, and early
recognition and treatment are essential to good patient
outcomes.
Although significant variation exists in timing and severity,
HIT typically occurs 5 to 15 days after initial heparin
exposure. New-onset thrombocytopenia should alert the
clinician that heparin cessation and HIT antibody testing are
necessary. The "4T" score (thrombocytopenia, timing of
platelet decrease, sequela of thrombosis, and other causes of
thrombocytopenia) is used at many centers to differentiate
patients into either low risk or intermediate-to-high risk for
HIT. Patients are assigned 0 to 2 points for each T, and those
at low risk (<3 points overall) have a risk of less than 2% of
clinically relevant HIT.
Patients with HIT can develop both arterial and venous
thromboses. Prompt anticoagulation with a novel agent is
warranted. Direct thrombin inhibitors such as argatroban and
bivalrudin are considered first-line therapy for HIT.
Bowel rest and parenteral nutrition will not affect the output
or closure rate of a diverted fistula and may lead to
malnutrition and bacterial overgrowth. Endoscopic injection
of fibrin glue was reported in a small series with limited
success, but this would typically be reserved for patients with
persistent fistulas rather than used as a primary intervention.
Desmopressin is used for patients with von Willebrand
disease and has not been studied in HIT. Transfused platelets
would be counterproductive in preventing thrombotic
complications. Enoxaparin is associated with HIT as well and
is not used due to concern for cross-reactivity. Warfarin is not
used for HIT due to its slow rate of onset along with the
associated transient hypercoagulability, with several reports
of warfarin-induced skin necrosis being tied to HIT treatment.
Laparotomy with repair of the anastomotic defect would be
aggressive and technically difficult, and such a repair, when
warranted, would be better approached transanally.
Laparotomy would be appropriate for uncontrolled sepsis,
especially if the patient was not initially diverted.
Anastomotic resection and end colostomy should be reserved
for patients with severe anastomotic breakdown and
associated pelvic sepsis.
5. A 55-year-old man undergoes a laparoscopic sigmoid
colectomy for diverticulitis. Which of the following
interventions is associated with a decreased rate of surgical
site infection in this patient?
4. A 74-year-old man undergoes a Whipple procedure for
pancreatic cancer and is treated with prophylactic doses of
subcutaneous unfractionated heparin after surgery. On
postoperative day 5, his platelet count decreases from
150,000/mm3 to 40,000/mm3 (150,000-400,000/mm3), and
a heparin-induced thrombocytopenia antibody is positive.
After stopping heparin, what is the most appropriate initial
treatment?
A.
B.
C.
D.
E.
A.
B.
C.
D.
E.
ANSWER:
Desmopressin
Platelet transfusion
Argatroban
Enoxaparin
Warfarin
ANSWER:
Intraoperative normothermia
Prophylactic antibiotics for 48 hours
Iodine-impregnated adhesive drapes
Preoperative chlorhexidine shower
Incisional gentamicin sponge
A
Surgical site infections (SSIs) are common after colorectal
surgery, with several modifiable and nonmodifiable risk
factors. With the increasing focus on patient outcomes as a
metric for reimbursement, more attention is being paid to
interventions and SSI prevention bundles to decrease
infection rates, despite varying levels of validating evidence.
Surgeons should be familiar with not only the SSI prevention
guidelines developed by multiple organizations but also the
quality of the supporting literature used to formulate these
guidelines.
C
Up to 17% of patients treated with unfractionated heparin
(UFH) will develop anti-heparin-PF4 antibodies (also known
31
Hypothermia is common during major abdominal surgery,
and it is known to be associated with higher rates of SSI.
Well-designed randomized controlled trials demonstrated
decreased rates of SSI when core body temperature is
maintained above 36°C.
often have a dark brown hue. Because sedated patients may
have other causes of hypoxia, a high clinical index of
suspicion is required. An arterial blood gas with
methemoglobin level should be obtained. Methemoglobin
levels in the normal patient should be close to 0%, but they
may be slightly elevated in patients who smoke.
Continuing antibiotics for 48 hours after surgery does not
reduce SSI rates compared with a single preoperative dose,
and routine cessation of prophylactic antibiotics in the first 24
hours is appropriate. Although iodine-impregnated adhesive
drapes advertise the ability to reduce the wound's exposure to
skin flora, a Cochrane review demonstrated no reduction in
SSI with their use, as well as some evidence that they increase
infection rates. Another Cochrane review focused on
preoperative chlorhexidine showers and could find no benefit
to the practice compared with either placebo or a simple bar
of soap. A 2010 randomized controlled trial of gentamicin
sponges actually demonstrated a significantly higher rate of
SSI compared with no intervention.
Methylene blue acts as an electron donor, converting
methemoglobin back to hemoglobin. It should be
administered at an initial dose of 50 to 100 mg intravenously.
If patients do not improve after administration, there are
several possibilities, inducting glucose-6-phosphate
dehydrogenase deficiency and even methylene blue overdose,
which causes worsening methemoglobin at very high doses
because it is also an oxidizing agent. Patients with refractory
methemoglobinemia can be considered for exchange
transfusions or hyperbaric oxygen.
Flumazenil is the primary pharmacologic treatment for
benzodiazepine overdose, whereas naloxone is used for
narcotic overdose. Dantrolene is administered for malignant
hyperthermia. Endotracheal intubation would be appropriate
if the sedated patient could not protect his airway, but it would
not improve the patient's oxygenation in the presence of high
levels of methemoglobin.
6. A 42-year-old man is undergoing esophagogastroduodenoscopy for new-onset dysphagia. He receives topical
benzocaine along with intravenous midazolam and fentanyl
before the procedure. Despite no abnormal findings during
the procedure, the patient appears cyanotic and reports
shortness of breath unresponsive to supplemental oxygen.
Pulse oximetry shows an oxygen saturation of 88%. Arterial
blood gas is obtained, showing a PaO2 of 200 mm Hg, PaCO2
of 30 mm Hg, and a methemoglobin level of 35% (0-3%).
What is the most appropriate next step?
A.
B.
C.
D.
E.
7. A 72-year-old woman undergoes an open sigmoid
colectomy for colon cancer. Which of the following
interventions reduces the incidence of postoperative ileus in
this patient?
A.
B.
C.
D.
E.
Flumazenil
Naloxone
Methylene blue
Dantrolene
Endotracheal intubation
ANSWER:
Methylnaltrexone
Sugar-free chewing gum
Wound infiltration with liposomal bupivacaine
Magnesium citrate
Bisacodyl suppositories
ANSWER:
C
B
Enhanced recovery after surgery (ERAS) protocols for
patients undergoing colorectal surgery are derived from
studies evaluating the efficacy of interventions designed to
reduce the morbidity and cost of surgical procedures and
therefore improve outcomes and value.
Methemoglobinemia is a well-known but uncommon
complication of topical benzocaine, occurring in 1 of every
7000 exposures. It is caused by mucosal absorption of
benzocaine, which can lead to the oxidation of ferrous (Fe2+)
to ferric (Fe3+) iron. Iron in hemoglobin must be in its reduced
(Fe2+) state for normal oxygen exchange to occur. This
oxidation of hemoglobin not only leads to a functional anemia
but also increases its affinity for oxygen, thus shifting the
oxyhemoglobin dissociation curve to the left and leading to
less oxygen delivery to tissues.
One such intervention, providing sugar-free chewing gum
perioperatively, is as a method of sham feeding, with the hope
that the mastication motion will promote intestinal motility
through the cephalic phase of vagal enteric stimulation. The
true mechanism is not entirely understood, and a randomized
controlled trial of sugared chewing gum did not show a
benefit, insinuating that the hexitols in sugar-free gum may
have a laxative effect and contribute to bowel motility. A
meta-analysis summarizing the existing literature concluded
that sugar-free chewing gum is an inexpensive and effective
way to reduce postoperative ileus, and it is well-tolerated
without any detrimental effect on patient outcomes
Patients with methemoglobinemia will become increasingly
cyanotic as methemoglobin levels increase. The cyanosis is
typically unresponsive to supplemental oxygen. Pulse
oximetry will generally underestimate the degree of hypoxia,
with readings of 85 to 90% despite a worsening clinical
picture. Of note, the PaO2 will be elevated and the blood will
32
Methylnaltrexone is currently indicated for opioid-induced
constipation, but it was initially studied as an intervention to
reduce postoperative ileus. Two large multicenter
randomized controlled trials failed to show a reduction in
postoperative ileus compared with placebo. Liposomal
bupivacaine is gaining in popularity as a component of
multimodal pain control in ERAS protocols. However,
current data do not demonstrate superiority to conventional
bupivacaine. Laxatives such as magnesium citrate and
stimulants such as bisacodyl will induce diarrhea, but they
will not increase small intestinal motility or reduce
postoperative ileus.
Data regarding the optimal modality and timing of renal
replacement therapy are conflicting. However, when patients
are hemodynamically abnormal and require vasopressor
support, a continuous mode of renal replacement therapy is
preferred. Continuous modes require smaller volumes of
blood to be removed at a time compared with intermittent
hemodialysis and are better tolerated in hypotensive patients.
A sodium bicarbonate infusion is used for patients with
acidosis; however, starting a sodium bicarbonate infusion is
generally not recommended until the serum pH is less than
7.15. Also, there are no data confirming any reduction in
morbidity and mortality for its use in renal failure.
Aggressive diuretic therapy used in the early stages of AKI to
treat volume overload and hyperkalemia is possible.
However, once a patient advances to renal failure, renal
replacement therapy is the preferred modality of
management. Low-dose dopamine infusions were once
erroneously thought to be renal protective via a mechanism
of increased renal blood flow. There are currently no data to
support the use of a dopamine infusion as prevention or
treatment of AKI.
8. A 65-year-old woman with well controlled type 2 diabetes
mellitus presents with perforated appendicitis. She is taken to
the operating room for exploration, drainage of intraabdominal abscess, and ileocecectomy. She is admitted to the
surgical intensive care unit postoperatively in septic shock.
Overnight, she is resuscitated with 9 L crystalloid. She is now
on norepinephrine and vasopressin infusions to keep her
mean arterial pressure above 65 mm Hg. On postoperative
day 1, she is hypoxic with pulmonary edema on chest x-ray.
Her serum potassium is 5.9 mmol/L, her serum creatinine
increased from 1.5 to 5.4 mg/dL (0.4-1.3 mg/dL), her serum
blood urea nitrogen is 60 mg/dL (7-20 mg/dL), her serum
bicarbonate is 13 mmol/L (20-29 mmol/L), and her pH is
7.21. Her urine output is 0.3 mL/kg/hour for the last 12 hours.
What is the next step in managing her renal failure?
A.
B.
C.
D.
E.
9. Which of the following components of an infection
prevention bundle has the most significant impact in reducing
surgical site infections in elective colorectal surgery patients?
A.
B.
C.
D.
Preoperative shower with 4% chlorhexidine gluconate
Mechanical bowel preparation
Intraoperative abdominal irrigation with antibiotic
Mechanical bowel preparation combined with oral
antibiotics
E. Dedicated instruments for wound closure
Continuous renal replacement therapy
Intermittent hemodialysis
Furosemide 80 mg intravenously
Dopamine infusion
Sodium bicarbonate infusion
ANSWER:
ANSWER:
A
D
Surgical site infections (SSIs) after colorectal surgery are a
significant cause of morbidity and mortality and remain an
important national quality indicator. Mechanical bowel
preparation plus oral antibiotics was a mainstay in colorectal
surgery for decades, but several publications questioned the
efficacy of mechanical bowel preparation. Numerous
randomized controlled trials failed to show any decrease in
SSIs or anastomotic leak. A major criticism of these trials was
omission of the oral antibiotic portion of the standard bowel
preparation. The American College of Surgeons National
Surgical Quality Improvement Program (NSQIP)
retrospectively evaluated 4999 patients who underwent
colectomy. Patients who had a combined mechanical bowel
preparation and oral antibiotics had a lower 30-day rate of
superficial SSIs, anastomotic leak, and 30-day readmission,
compared with mechanical bowel preparation alone.
Acute kidney injury in the postoperative period is associated
with increased morbidity and mortality. Two classification
systems were proposed in the early 2000s: the RIFLE criteria
and the Acute Kidney Injury Network (AKIN) staging
system. These systems provide concise definitions of the
extent of injury and prognosis. Both systems consider
increases in serum creatinine, either an absolute number or an
increase from baseline, and urine output criteria. This patient
had a marked increase in serum creatinine and has oliguria.
According to the RIFLE criteria, she has Failure; she is in
AKIN stage III.
Additionally, she is acidemic, with a serum pH of 7.21 and
bicarbonate of 13 mmol/L (20-29 mmol/L), and
hyperkalemic. She also shows evidence of volume overload
with hypoxemia and radiographic evidence of pulmonary
edema. This patient has several indications for renal
replacement therapy.
Infection prevention bundles are used to reduce the rates of
infection related to central line insertions and mechanical
ventilation. Several interventions in the preoperative and
33
perioperative arenas are proposed to reduce the rates of SSI
in colorectal patients, and institutions have grouped them
together in an infection prevention bundle. One group studied
the impact of each component of the infection prevention
bundles: mechanical bowel preparation plus oral antibiotics,
preoperative chlorhexidine shower, preoperative hair
clipping, skin preparation with a standard chlorhexidine
alcohol solution, intraoperative antibiotic irrigation, and a
clean closure protocol with dedicated instruments.
Multivariate analysis showed that the mechanical bowel
preparation with oral antibiotics had the greatest effect on
reducing SSIs.
The risk of stroke in patients with nonvalvular atrial
fibrillation can be calculated with the CHADS2 score. The
CHADS2 score is calculated by adding up points from the
presence of congestive heart failure, hypertension, age older
than 75 years, diabetes mellitus, and history of stroke or
transient ischemic attack. The patient in our question has 2
points for hypertension and diabetes, giving him a 4.0%
yearly risk of thromboembolic event with no warfarin. Dual
antiplatelet therapy is not an effective treatment to prevent
stroke in patient with nonvalvular atrial fibrillation.
11. Which of the following is associated with decreasing the
rate of central line associated blood stream infections?
10. A 63-year-old man with a symptomatic midline ventral
hernia from prior open appendectomy presents with a
reducible bulge. He has a history of well-controlled
hypertension, diabetes mellitus type 2, and paroxysmal atrial
fibrillation. He has been on warfarin for the last 5 years. He
has had worsening symptoms and pain from the hernia over
the past 6 months and 2 episodes of incarceration requiring
emergency department visits. Which of the following
statements is true regarding this patient's perioperative
anticoagulation?
A.
B.
C.
D.
E.
ANSWER:
A
Central line associated blood stream infections (CLABSI) are
a significant source of morbidity and increased costs in
surgical patients. The most common route of contamination
and subsequent infection of a central line is migration of skin
microorganisms from the insertion site to the catheter tract.
To decrease the contamination of the catheter, several antiinfectious procedures were combined into a single central line
insertion bundle. Several different components may be
included in a central line insertion bundle; however, most
include the following: hand washing, maximal sterile barrier
precautions, chlorhexidine skin preparation, avoiding
femoral vein placement, and removal of unnecessary
catheters. The use of a central line insertion bundle reduced
CLABSI by 66% in a large multi-institution trial. Additional
components to a central line insertion bundle include
applying a sterile dressing, replacing the dressing every 48
hours, and using a chlorhexidine-impregnated dressing,
A. His yearly risk of thromboembolic events is 8%.
B. Perioperative bridging with low molecular weight
heparin (LMWH) decreases his risk of thromboembolic
events by 50%.
C. Warfarin should be stopped 3 days preoperatively.
D. Initiation of postoperative bridging with LMWH
increases his risk of major postoperative bleeding.
E. Dual antiplatelet therapy should be initiated to reduce the
risk of perioperative stroke.
ANSWER:
Central line insertion bundle
Polyvinyl chloride catheter
Prophylactic intravenous antibiotics
Routine guidewire exchange of the catheter
Placement in femoral vein under ultrasound guidance
D
Patients with atrial fibrillation are placed on lifelong
anticoagulation to reduce their risk of embolic stroke. When
they are scheduled to undergo surgery, most patients have
their warfarin held preoperatively, typically 5 days before
surgery. Due to the concern of an embolic event during this
time period, many patients undergo bridging anticoagulation
with a low molecular weight heparin (LMWH). Despite very
little data to support this practice, bridging anticoagulation
has remained in practice guidelines. A prospective, double
blind, randomized trial of 1884 low-risk patients compared
bridging with LMWH with no bridging in patients with
nonvalvular atrial fibrillation who had warfarin held in the
perioperative period. The incidence of arterial
thromboembolism and stroke was not different between the 2
groups (0.4% vs 0.3%) but the patients who underwent
bridging with LMWH had more than twice as much major
bleeding (1.3% vs 3.2%). Given no increase in stroke rate but
higher bleeding complications in the bridging group,
perioperative bridging anticoagulation is not recommended.
Several other interventions were studied but are not costeffective in reducing CLABSI rates. These are summarized
in guidelines provided by the Society of Critical Care
Medicine and Infectious Disease Society of America.
Prophylactic intravenous antibiotics and routine guidewire
catheter exchanges did not decrease the rate of CLABSI.
Catheters impregnated with chlorhexidine, minocycline,
rifampin, platinum, or silver can be used in patients who need
a central line for more than 5 days and in settings where other
components of the central line insertion bundle have not
reduced CLABSI rates. No association exists between
catheter material and CLABSI rates.
12. A 68-year-old man with chronic renal failure is dialysisdependent and has recurrent biliary colic. He presented for
34
elective cholecystectomy. His medical history was significant
for a myocardial infarction 5 months ago, after which a bare
metal stent was placed. He was taking aspirin and
clopidogrel. Clopidogrel was held for 5 days before surgery,
but aspirin was continued. Two days after cholecystectomy,
he has chest pain and a myocardial infarction. What factor
most contributed to his major adverse cardiac event after
surgery?
infarction. Risk of myocardial infarction is highest if surgery
is performed within 30 days of preoperative myocardial
infarction and remains greater than 5% at 3 to 6 months. After
6 months, the relative risk for early postoperative myocardial
infarction decreases further and remains low up to 1 year after
surgery.
A.
B.
C.
D.
E.
Items 13-15
Each lettered response may be selected once, more than once,
or not at all.
Withholding clopidogrel in the perioperative period
Use of bare metal stent rather than drug-eluting stent
Myocardial infarction within the past 6 months
Dialysis dependence
Male sex
ANSWER:
A.
B.
C.
D.
E.
C
Dabigatran
Rivaroxaban
Fondaparinux
Clopidogrel
Warfarin
13. Reversed by Vitamin K
Elective noncardiac surgery is associated with a small risk of
postoperative major adverse cardiac events. Risk
stratification before elective surgery is important, and
surgeons should be aware of preoperative factors that
increase this risk of major adverse cardiac events when
deciding whether surgery should be performed or delayed.
Demographics such as advanced age and male sex are
associated with postoperative cardiac complications, as are
chronic preoperative conditions such as coronary artery
disease, congestive heart failure, cerebrovascular disease, and
renal insufficiency. Acute conditions that carry a high risk
include acute coronary or aortic disease, stroke, major
trauma, or emergency surgery.
14. Selective Factor Xa inhibitor
15. Specific reversal agent is idarucizumab
ANSWERS:
E, B, A
Patients taking anticoagulants can present challenges to the
surgeon. The risk of bleeding must be balanced with the need
for normal or near normal coagulation. Several new oral
anticoagulants are now in wide use.
Dabigatran is a thrombin inhibitor that binds directly to
thrombin. It lengthens the partial thromboplastin time (PIT)
but in a non-dose-related fashion. Additionally, the
prothrombin time (PT)/intemational normalized ratio (INR)
is not useful in establishing the degree of drug activity.
Although the classic thrombin time is too sensitive, the
development of the dilute thrombin time is useful to estimate
the quantity of the drug in circulation. As a corollary, a
normal thrombin time suggests very low or no drug activity,
a useful tool in an acute situation. Dabigatran is dialyzable.
Idarudzumab is a monoclonal antibody preparation that is a
specific reversal agent for dabigatran. It has been approved
for the reversal of dabigatran in the setting of life-threatening
hemorrhage and when anticipating invasive procedures or
surgery that cannot be delayed for at least 8 hours.
As the population of individuals with coronary stents
increases, so does the population in need of noncardiac
surgery who have coronary stents. Recent cardiac stent
placement is associated with postoperative major cardiac
events; however, stent type is not independently associated
with major cardiac event if the elective surgery is delayed
more than 6 months after stent placement. At the same time,
perioperative management of antiplatelet therapy can be a
challenge in these patients, especially in patients with drugeluting stents. American College of Cardiology/American
Heart Association guidelines recommend delaying elective
surgery for a period of at least 6 months for patients with
drug-eluting stents if possible, especially if dual antiplatelet
therapy is discontinued perioperatively. By contrast, elective
noncardiac surgery can be performed 1 month after bare
metal stent placement, and the risk for postoperative
myocardial infarction is highest if surgery is performed
within 30 days of stent placement, regardless of whether a
bare metal or drug-eluting stent were placed. Common
practice is to discontinue clopidogrel and to continue aspirin
in the perioperative period.
Rivaroxaban is a direct-binding Factor Xa inhibitor. It
elevates both activated PTT (aPTT) and PTT but not in a
consistent fashion, limiting the utility in these in determining
anticoagulation activity. It is not effectively dialyzable and
has no specific reversal agent approved. Andexanet alfa is a
recombinant analog of factor Xa and may be available in the
future as a specific inhibitor for Factor Xa inhibitors.
Currently, most reversal protocols use a 4-factor prothrombin
complex concentrate in life-threatening situations.
Despite recent advances in perioperative care, patients with a
recent myocardial infarction remain at very high risk for
postoperative cardiac complications. The risk of
postoperative cardiac event decreases with greater delay in
the timing of surgery after a preoperative myocardial
35
Fondaparinux binds to antithrombin III, resulting in an
inhibition of Factor Xa. It elevates both the PT and aPTT but
has no effect on thrombin time.
antibiotic use. The risk of infection with C. difficile is also
linearly related to the degree of perioperative add suppression
with both histamine receptor type 2 blockers, such as
famotidine or ranitidine, and proton pump inhibitors, such as
omeprazole, pantoprazole, or lansoprazole.
Clopidogrel is an antiplatelet agent that irreversibly blocks
the adenosine diphosphate receptor P2Y12 on platelet
membrane, inhibiting platelet activation. This is a separate
action from aspirin, which inhibits thromboxane systems via
an anti-Cox-1 mechanism. Both drugs affect platelets for the
remainder of their lifetime.
Many drugs used in the perioperative period can predpitate or
worsen the severity of delirium. Common causes of delirium
indude polypharmaceutical drug effects and patient factors
such as age and organic neurologic dysfunction.
Diphenhydramine, often used as a sedative or "sleep aid," is
a well-recognized predpitator of delirium in the elderly in the
perioperative period.
Warfarin is a long-used oral anticoagulant. It inhibits the
Vitamin K-dependent Factors II, VII, IX, and X.
Additionally, it inhibits the anticoagulant factors proteins C
and S. Warfarin interacts with KO reductase, inhibiting
oxidized Vitamin K to be reduced to normal Vitamin K. It is
monitored via the PT/INR assay. It is the only oral
anticoagulant to be reversed by Vitamin K. It can also be
reversed with fresh frozen plasma or prothrombin complex
concentrates.
Serotonin syndrome is a potentially life-threatening disorder
that can result from administering linezolid in a patient taking
other medications that may interact with it. This is because it
was originally developed for its nonselective monoamine
oxidase inhibitory properties. Common drug interactions
with linezolid include selective serotonin reuptake inhibitors,
such as paroxetine, sertraline, or citalopram, as well as
selective norepinephrine reuptake inhibitors, such as
venlafaxine or mirtazapine. Symptoms include high body
temperature, agitation, increased reflexes, tremor, sweating,
dilated pupils, and diarrhea. Body temperature can increase
to more than 41.1 °C. A host of other common medications
prescribed in the perioperative period including sedatives,
such as trazodone, or analgesics, such as tramadol, can
precipitate the serotonin syndrome as well. Herbal products
such as St John's Wort are also associated with the serotonin
syndrome.
Items 16-19
Each lettered response may be selected once, more than once,
or not at all.
A.
B.
C.
D.
E.
Anastomotic leak
Clostridium difficile infection
Serotonin syndrome
Delirium
Wound infection
16. Ketorolac
Although not a perioperative medication, tobacco use in the
perioperative period is a definite risk factor for surgical site
infection and wound complications. The abstinence of
tobacco products for 8 to 12 weeks before elective surgery is
associated with better outcomes. Perioperative serum or urine
testing of cotinine, a by-product of nicotine metabolism can
be used to risk-stratify for elective surgery.
17. Pantoprazole
18. Linezolid
19. Cotinine
ANSWERS:
A, B, C, E
20. When used in the context of an enhanced recovery
strategy after laparotomy with bowel resection and
anastomosis, the addition of alvimopan results in
Perioperative care of the surgical patient should include a
fundamental knowledge of potential negative effects of drug
treatments prescribed in the postoperative period as well as
ramifications of patient factors that enhance the risk of
surgical procedures.
A.
B.
C.
D.
E.
Although not firmly a cause-and-effect relationship, surgeons
should be aware that there is a definite association in large
cohort studies between nonsteroidal antiinflammatory drugs
(NSAIDS) such as ketorolac and a risk of colonic anastomotic
dehiscence in both elective and urgent colon surgery. This is
especially in need of clarification because narcotic-sparing
regimens for enhanced recovery pathways liberally use
NSAIDS as a component of care.
decreased anastomotic leaks.
less nausea.
increased hospital readmission within 10 days.
shorter time to bowel movement
decreased pain scores.
ANSWER:
D
Enhanced recovery after surgery (ERAS) programs have had
several benefits, especially after colorectal surgery. They are
associated with decreased length of stay without increased
readmission rates and with improved patient satisfaction.
Two of the key components are adequate pain control and
The perioperative risk of Clostridium difficile superinfection
of the colon is not uncommon in surgical patients, especially
in carriers of the bacteria or those exposed to prolonged
36
early initiation of oral intake. However, the use of opioid pain
medications can contribute to postoperative gastrointestinal
dysfunction and ileus. Alvimopan, a mu-opioid antagonist,
can mitigate the gastrointestinal side-effect of narcotics
without interfering with the analgesic effects. When used in
the context of an ERAS program, alvimopan results in a
shorter time to initial bowel movement after operation. Use
of alvimopan is not associated with anastomotic leaks rates,
postoperative nausea, increased early hospital readmission
(10 days), or increased pain scores. There is added pharmacy
cost with its use, but this is offset by the decreased length of
stay associated with a shorter ileus period.
22. Use of a restrictive red blood cell transfusion protocol
(Hgb <7 g/dL) for hemodynamically normal intensive care
unit patients results in
A.
B.
C.
D.
E.
ANSWER:
4 days.
7 days.
10 days.
14 days.
48 hours beyond normalization of fever and white blood
cell count.
ANSWER:
D
Transfusion practices in the intensive care unit have
undergone significant changes over the last 10 years.
Although red blood cell transfusion can be lifesaving for
someone with active hemorrhage and hemodynamic
abnormality, the detrimental effects of red cell transfusions
are not negligible. Based on data from large clinical trials, it
has become increasingly clear that a more restrictive policy
toward red cell transfusion for hemodynamically normal
patients in the intensive care unit has several benefits. In this
setting, mortality rates are at least equivalent (if not lower)
for a restrictive policy. The percentage of patients transfused
is decreased (from approximately 25% to approximately
18%), and mean direct costs of transfusion are reduced by
approximately 25%. Healthcare-associated infections are
decreased. Hospital length of stay and readmission rates are
decreased as well with restrictive transfusions.
21. After a laparoscopic appendectomy with adequate source
control for perforated appendicitis in a healthy patient,
antibiotics should be prescribed for
A.
B.
C.
D.
E.
increased mortality.
increased length of stay.
increased readmission rates.
decreased percentage of patients transfused.
increased fresh frozen plasma use.
A
Surprisingly little data are available on the duration of
antibiotic treatment for many surgical infections. Recently,
more data are emerging that support shorter durations as
being equally effective.
Restrictive red cell transfusion policies are associated with
similar reductions in transfusion of other blood components,
including plasma and platelets.
The Study to Optimize Peritoneal Infection Therapy (STOPIT) trial enrolled adult patients with
•
•
•
23. A 62-year-old woman is admitted with a 2-day history of
right upper quadrant pain and is diagnosed with acute
cholecystitis. She has no angina, and her electrocardiogram is
normal, but she is on clopidogrel for a bare metal coronary
stent placed 1 year ago. What is the next step in her
management?
a complicated intra-abdominal infection
fever, leukocytosis, or gastrointestinal tract dysfunction
from peritonitis
an intervention to achieve source control
Participants were randomized (1:1, open-label) to 4 full days
of antimicrobial treatment after the initial source-control
procedure (experimental group) or to antimicrobial therapy
until 2 days after resolution of systemic inflammatory
response (control group). The primary outcome of the study
was a composite score of the occurrence of surgical site
infections, intra-abdominal infection, or death within 30 days.
A total of 518 patients were enrolled. There were no
significant differences between the 2 groups in either the
composite outcome or its individual components. Thus, in
patients with adequate source control, a fixed 4-day course is
as effective as longer courses based on fixed number of days
or physiologic response.
A.
B.
C.
D.
E.
Proceed with laparoscopic cholecystectomy
Delay the operation for 5 days
Transfuse platelets intraoperatively
Administer tranexamic add preoperatively
Start a preoperative heparin drip
ANSWER:
A
For patients with uncomplicated acute cholecystitis,
laparoscopic cholecystectomy generally should be done
during the index hospital stay. However, in patients on
antiplatelet therapy, there is always a concern for increased
risk of bleeding with operation, as well as the concern for
coronary stent occlusion if the medication is discontinued or
reversed.
Additional studies in complicated appendicitis patients with
adequate source control after laparoscopic appendectomy
showed that shorter courses (in the range of 3-5 days) do not
have worse outcomes.
37
For patients undergoing laparoscopic procedures,
continuation of a single antiplatelet agent during the operative
period is not associated with an increased incidence of
operative or postoperative bleeding. Thus, many guidelines
recommend continuation of a single antiplatelet agent
through the operative period in patients at high risk for
thrombotic complications and procedures with low-risk of
postoperative bleeding (such as a laparoscopic
cholecystectomy). In this case, the appropriate next step is to
proceed with laparoscopic cholecystectomy. Waiting an
additional 5 days will not affect the risk of bleeding and will
increase the risk for conversion to open operation. Because
the risk of postoperative bleeding is not increased, platelet
transfusion would not benefit this patient. Likewise,
tranexamic add is an antifibrinolytic agent and does not affect
platelet function. There is no evidence that bridging
anticoagulation with a heparin drip reduces the risk of stent
thrombosis after discontinuation of an antiplatelet agent.
25. Which of the following antihypertensive medications
should be continued on the day of elective surgery?
A. Beta-blocker
B. Calcium channel blocker
C. Angiotensin converting enzyme inhibitor
D. Alpha-2 agonists (clonidine)
E. Furosemide
ANSWER:
Early recommendations by the American College of
Cardiology (ACC) and American Heart Association (AHA)
included perioperative beta-blocker therapy for patients
undergoing noncardiac surgery with untreated hypertension,
known coronary artery disease, or other cardiac risk factors.
Since those recommendations, however, larger studies
demonstrated that although initiation of beta-blockade
therapy decreased the risk of perioperative nonfatal
myocardial infarction, it increased the risk of stroke and
death. Consequently, a more recent ACC/AHA guideline
discouraged initiating new therapy within 1 day of surgery.
However, for patients on chronic beta-blocker therapy, there
is a strong recommendation that beta blockers be continued
in the perioperative period to avoid adverse cardiac events.
24. Standardized post discharge ileostomy pathways with
comprehensive patient education and close outpatient followup result in
A. increased total cost of care.
B. increased 30-day adverse events.
C. decreased readmission rates for dehydration.
D. increased hospital stays for patients who are readmitted.
E. decreased patient satisfaction.
ANSWER:
A
No evidence suggests that continuation of calcium channel
blockers in the perioperative period provides any benefit in
terms of postoperative myocardial infarction or cardiac death.
At the same time, there is also no significant detriment to
continuing calcium channel blocker therapy on the day of
surgery, and the decision of whether to continue can be left to
the discretion of the surgical team and patient.
C
For patients with new ileostomies, readmissions can be
frequent, with dehydration due to high ileostomy output being
the most common cause. Several studies investigated the use
of ileostomy pathways to reduce the morbidity of ileostomies
and reduce the rate of readmission. Although each study
varied somewhat in the details, the main components
included
1) detailed preoperative education;
2) specific postoperative interventions (e.g., stoma care,
dietary instructions);
3) discharge instructions (e.g., ileostomy diary, phone
contact numbers); and
4) frequent contact with the patient by phone call in the first
few weeks to assess progress, monitor the ileostomy, and
provide new or reinforce existing instructions.
Similarly, angiotensin converting enzyme (ACE) inhibitors
are commonly prescribed medications. Use of ACE inhibitors
on the day of surgery is associated with intraoperative
hypotension but does not cause worse cardiovascular or renal
outcomes. Meanwhile, there is no convincing evidence that
perioperative use of ACE inhibitors is protective. Thus,
ACC/AHA recommendations suggest that it is reasonable to
continue ACE inhibitor therapy in the perioperative period
but holding them is acceptable as well.
There is a similar concern that loop diuretics used on the day
of noncardiac surgery could increase the risk of intraoperative
hypotension; however, the risk of developing perioperative
adverse cardiovascular events is not increased in patients on
continued furosemide therapy. In these patients, however,
there is no known benefit to continued therapy.
The main benefit of these pathways and frequent contact is a
50 to 100% reduction in the number of admissions due to
dehydration. Overall, 30-day adverse events are decreased.
Additionally, for those patients who do need readmission,
their lengths of stay tend to be shorter. There is some
incremental increase in the cost of the intensive out-patient
follow-up, but this is more than offset by the cost saving of
reduced readmissions (i.e., total cost of care goes down).
Finally, patient satisfaction with these programs is very high.
Alpha-2 agonists are not recommended as cardiac
prophylaxis in patients who are undergoing noncardiac
surgery, because they have no role in perioperative cardiac
protection and may increase postoperative nonfatal
myocardial infarction. Sudden discontinuation of ongoing
alpha-2 agonist therapy can result in hypertension, headache,
or agitation, but continuation on the day of surgery is not
proven to provide perioperative benefit.
38
26. Prophylactic placement of an inferior vena cava (IVC)
filter before bariatric surgery compared with not placing an
IVC filter is associated with which of the following outcomes
A.
B.
C.
D.
E.
27. A 68-year-old man presents with large-volume lower
gastrointestinal bleeding resulting in hypotension and
tachycardia, hemorrhagic shock, and need for blood
transfusions. The patient has been anticoagulated with
dabigatran for treatment of atrial fibrillation, and the last dose
was 4 hours ago. The optimal anticoagulant reversal agent in
this patient is
A. 3-factor prothrombin complex concentrate.
B. fresh frozen plasma.
C. activated Factor Vila.
D. idarucizumab.
E. andexanet alfa.
Higher postoperative deep vein thrombosis rate
Lower pulmonary embolism rate
Reduced use of perioperative anticoagulation
Shorter length of stay
Decreased all-cause 90-day mortality
ANSWER:
A
Venous thromboembolism (VTE) is a rare complication after
bariatric surgery. Nonetheless, bariatric patients are
considered to be at moderate risk for VTE, and it remains a
leading cause of postoperative morbidity arid mortality.
Factors that increase these patients' risk for postoperative
VTE include prior VTE, hypercoagulable state, higher BMI,
male sex, immobility, pulmonary hypertension, obesity
hypoventilation syndrome, venous stasis disease, and
prolonged operative time. Thus, VTE prophylaxis is standard
practice in bariatric surgery. Mechanical prophylaxis is
recommended for all bariatric surgical patients, along with
early ambulation. In addition, most data suggest benefit for
the combined use of mechanical and chemoprophylaxis in
these patients.
ANSWER:
Idarucizumab is approved by the US Food and Drug
Administration as a specific reversal agent for dabigatran. It
is a monoclonal antibody that directly neutralizes the effects
of dabigatran and has no effect on other anticoagulants. It has
immediate onset and provides full reversal up to 24 hours in
most patients. Prothrombin complex concentrate (PCC; 3factor), Factor Vila, fresh frozen plasma, and andexanet-alfa
are not indicated for dabigatran reversal. Four-factor PCC has
been used to reverse dabigatran but is not as effective as
idarucizumab.
Four-factor PCC is the optimal reversal agent for all Factor
Xa inhibitors and warfarin in life-threatening bleeding. PCC
replaces coagulation factors but does not directly neutralize
the activity of the oral anticoagulants. PCC onset of action is
5 to 15 minutes and duration of effect is 12 to 24 hours.
Inferior vena cava (IVC) filters, particularly when retrievable,
were of interest, especially in the high-risk bariatric
population. They offer a potentially reversible, effective
mode of VTE prophylaxis that obviates the risk of
anticoagulation. A systematic review of IVC filter placement
in bariatric surgery patients found an overall higher risk of
deep vein thrombosis and pulmonary embolism in patients
receiving a preoperative filter. IVC filters are associated with
multiple device-related complications, including filter
migration, thrombosis, embolization, occlusion, and fracture.
In addition, prophylactic placement of IVC filters does not
decrease the use of anticoagulation, mortality, or length of
stay.
Medication
Dabigatran
Mechanism of Action
Half-life (hours)
Direct thrombin inhibitor 12-17
Rivaroxaban Factor Xa inhibitor
5-9
(11-13 in elderly)
Apixaban
Factor Xa inhibitor
12
Edoxaban
Factor Xa inhibitor
10-14
D
Plasma is sometimes indicated for warfarin reversal.
Andexanet alfa is a direct reversal agent for Factor Xa
inhibitors (rivaroxaban, apixaban, edoxaban; table 27.1).
Reversal
Assays
Oral charcoal (must give
within 2 hours of last dose)
Idarucizumab
Thrombin clotting time or
Ecarin clotting time; if normal
no treatment needed
3- or 4-factor PCC
Andexanet alfa
3- or 4-factor PCC
Andexanet alfa
3- or 4-factor PCC
Andexanet alfa
Anti-Xa assay; if normal no
treatment needed
Anti-Xa assay; if normal no
treatment needed
Anti-Xa assay; if normal no
treatment needed
Current as of December 2018.
Table 27.1.
39
28. A 44-year-old man presents with a history of sigmoid
colon stricture and colovesical fistula due to complicated
diverticulitis. He underwent preoperative epidural analgesia
with morphine and bupivacaine. His procedure was a
laparoscopic-converted-to-open sigmoid colectomy with
stapled colorectal end-to-end anastomosis in modified
lithotomy position. Intraoperative findings were a large
inflammatory mass densely adherent to the posterior wall of
the bladder, small bowel, retroperitoneum, and sacral
promontory. Immediately postoperatively, he complained of
left lower extremity weakness in the femoral nerve
distribution and decreased motor function. The next
immediate step in management is
A.
B.
C.
D.
E.
obtain a CT scan of pelvis.
obtain a MRI of the thoracic and lumbar spine.
remove the bupivacaine from the epidural infusion.
decrease the epidural catheter infusion.
discontinue the epidural catheter.
ANSWER:
Figure 28.1. Nerves of the pelvis.
To minimize nerve trauma in the lithotomy position, the
following should be considered:
• Minimize abduction and external hip rotation.
• Pad all areas at risk for tissue injury: hips, lateral fibulas,
posterior thighs, and heels.
• Ensure that hips and knees are moderately flexed and
securely supported.
• Direct the weight of the lower extremities toward the
soles of the feet.
• Avoid lower extremity tissue injury by ensuring that the
stirrup edges do not cut into the calf (e.g., peroneal
nerve), posterior thigh, or low on the Achilles tendon.
• Use shorter blades and periodic relief of pressure with
self-retaining retractors
B
When a patient develops lower extremity weakness
immediately postoperatively with an epidural catheter in
place, evaluation for possible epidural hematoma should be
the first priority. The optimal diagnostic test for epidural
hematoma is an urgent MRI of the thoracic and lumbar spine.
In a single-institution study of 43,200 epidural
catheterizations, 102 patients underwent spine MRI that
confirmed 6 cases of epidural hematoma (overall incidence 1
per 10,000 epidural blocks).
This patient had femoral neuropathy from deep pelvis
surgery. The mechanism is compression of the femoral nerve
against the pelvic sidewall as the nerve emerges from the
border of the psoas muscle before exiting the pelvis at the
inguinal ligament due to self-retaining retractors. Risk factors
for femoral nerve compression include the following:
• Thin subcutaneous fat layer (BMI <20)
• Operating time greater than 4 hours
• Narrow pelvis
• Self-retaining retractors, with extreme lateral traction
29. A 65-year-old patient presents for colectomy for sigmoid
colon cancer. He has a history of coronary artery disease and
underwent heart catheterization with drug-eluting stent
placement 6 months ago. He is on clopidogrel and aspirin
(325 mg daily). The most appropriate plan for his antiplatelet
medication is to
A. delay colectomy for 6 months.
B. stop clopidogrel and continue aspirin.
C. stop both clopidogrel and aspirin.
D. stop both and bridge with enoxaparin.
E. continue both.
In a study of 2304 patients who underwent major colorectal
surgery at a single institution, peripheral nerve injury
occurred in 0.2% (5/2211) of open procedures and 3% (3/93)
of laparoscopic procedures. There was no association
between age, sex, operative time, BMI, or American Society
of Anesthesiologists score and nerve injury.
Nerves are prone to stretching or compression in the
lithotomy position. The most common nerves affected are (1)
femoral and (2) lateral femoral cutaneous (figure 28.1). In
patients undergoing gynecologic pelvic surgery, a 2%
incidence has been reported, with 91% complete resolution at
a median time of 31.5 days.
ANSWER:
B
Dual antiplatelet therapy is indicated to prevent stent
thrombosis in patients with coronary stents. When these
patients need surgery, decisions regarding perioperative
antiplatelet therapy should be based on the bleeding risk of
the planned procedure, risk of stent thrombosis, and
alternative options.
This patient underwent drug-eluting stent placement 6
months ago. Modification of dual antiplatelet therapy is
appropriate and safe at this time with the risk of stent
40
thrombosis being acceptably low. The risk of a bleeding
complication on clopidogrel is sufficient that discontinuation
in the perioperative period is indicated. Aspirin can be safely
continued. Because of the underlying malignant diagnosis,
delaying the operation is not appropriate. Bridging with
enoxaparin will not provide additional benefit.
low (1-2 points), moderate (3-4 points), and high (>5 points)
risk of VTE to determine type and duration of prophylaxis.
High-risk patients should undergo chemoprophylaxis with
low molecular weight heparin (LMWH).
High-risk patients undergoing major abdominal surgery for
malignancy have the highest risk for postoperative VTE. Two
randomized trials demonstrated reduced VTE rates in these
patients with 4 weeks of LMWH chemoprophylaxis
compared with 1 week. The American College of Chest
Physicians Chest Guidelines for prevention of VTE in
nonorthopedic surgical patients state, "For patients at high
risk for VTE undergoing abdominal or pelvic surgery for
cancer, we recommend extended-duration, postoperative,
pharmacologic prophylaxis (4 weeks) with LMWH over
limited-duration prophylaxis (Grade 1B)."
Shorter durations of VTE pharmacologic prophylaxis such as
"only while hospitalized" or "until back to baseline
ambulatory status" are inadequately short. Four weeks'
duration is not associated with increased bleeding
complications;
however,
extending
duration
of
chemoprophylaxis beyond 4 weeks does increase the risk of
bleeding complications without providing additional benefit
in reducing VTE.
30.
A 67-year-old man has undergone pancreaticoduodenectomy for stage II pancreatic adenocarcinoma. His
Caprini score is 7. How long should he should be maintained
on low molecular weight heparin?
A.
B.
C.
D.
E.
Until back to his baseline level of ambulation
While hospitalized
1 week
4 weeks
3 months
ANSWER:
D
Postoperative venous thromboembolism (VTE) remains a
significant source of morbidity and mortality. The Caprini
score (table 30.1) stratifies patients into very low (0 points),
1 Point
Age 41-60 years
Minor surgery
BMI>25kg/m’
Swollen legs
Varicose veins
Pregnancy or postpartum
History of unexplained or
recurrent spontaneous
abortion
Oral contraceptives or
hormone replacement
Sepsis (<1 month)
2 Points
Age 61-74 years
Arthroscopic surgery
Major open surgery
(>45 minutes)
Laparoscopic surgery (>45
minutes)
Malignancy
Confined to bed (>72 hours)
Immobilizing piaster cast
3 Points
Age 2:75 years
History of VTE
Family history of VTE
5 Points
Stroke (<1 month)
Elective arthroplasty
Hip, pelvis, or leg fracture
Factor V Leiden
Acute spinal cord injury (<1
month)
Central venous access
Elevated serum homocysteine
Serious lung disease,
including pneumonia
(<1 month)
Abnormal pulmonary
function
Acute myocardial infarction
Congestive heart failure
(<1 month)
History of inflammatory
bowel disease
Medical patient at bed rest
(<1 month)
Abnormal pulmonary
function
Acute myocardial infarction
Congestive heart failure
(<1 month)
History of inflammatory
bowel disease
Medical patient at bed rest
Prothrombin 20210A
Lupus anticoagulant
Anticardiolipin antibodies
Heparin-induced
thrombocytopenia
Other congenital or acquired
thrombophilia
VTE = venous thromboembolism.
Table 30.1.
41
Perioperative Care Part IV
necessity within 6 months of placement of a drug-eluting
stent, antiplatelet therapy should be continued.
ITEMS 1-30
For each question, select the best possible response.
In the setting of pelvic surgery for cancer, continuation of
aspirin as single agent antiplatelet therapy, while holding
thienopyridines, offers a strategy to balance the risk of
perioperative bleeding against stent thrombosis.
Items 1-3
Each lettered response may be selected once, more than once,
or not at all.
A. Continue current antithrombotic agents and proceed with
elective procedure.
B. Discontinue antithrombotic agents in time for effects to
resolve before the elective procedure.
C. Change antithrombotic agents and continue with elective
procedure.
D. Defer the elective procedure until a later date.
E. Proceed with elective procedure.
4. Which of the following electric surgical devices is
characterized by generating temperatures as high as 300° and
having a slow heat dissipation rate?
A.
B.
C.
D.
E.
1. Patient receiving warfarin for deep vein thrombosis that
occurred 1 year ago and now requires wide local excision of
early-stage melanoma.
2. Patient presenting with a reducible inguinal hernia 3
months after placement of a drug-eluting coronary stent
followed by dual antiplatelet therapy.
ANSWER:
C
Surgeons should be familiar with how electric surgical
devices work. The electricity causes molecular vibration
within a cell, which generates heat and causes damage to the
cell. Cell death begins to occur at 50°C. The standard
monopolar energy device transfers an electrical impulse from
the instrument tip through the patient to the dispersion pad.
The energy provided at the tissue level causes the molecular
vibration within the cell and results in cell damage. With
higher energy, the damage extends further through the tissue.
While on lower energy, the damage will be more limited to
the surface of the tissue. The cut mode of a monopolar device
uses more energy and thus is able to penetrate or "cut"
through the tissue more. The cut mode can result in
temperatures up to 100°C. On coagulation mode, less energy
is used. Therefore, tissue damage is limited to the surface.
The damage of proteins leads to coagulum formation.
Coagulation mode reaches temperatures of about 60° C.
3. Patient who has completed preoperative therapy for a
surgically resectable rectal cancer and has received dual
antiplatelet therapy for a drug-eluting coronary stent that was
placed 6 months earlier
ANSWERS:
Bipolar surgical electricity
Advanced bipolar device
Ultrasonic dissector
Monopolar surgical electricity
ND-Yag laser device
B, D, C
Antithrombotic agents include both anticoagulant agents and
antiplatelet agents. When considering surgery for a patient
who is currently receiving anticoagulation therapy, the
surgeon must examine the nature and indication of the
surgical procedure as well as the anticoagulation therapy. The
surgeon must then weigh the necessity and timing of the
surgical procedure against the risk of bleeding due to
anticoagulation. Recommendations are available to help
guide this often-difficult clinical scenario.
Bipolar devices transfer energy between the 2 tips of the
instrument. Energy is transferred to the tissue that is grasped
by the instrument. Again, this energy results in molecular
vibration and the generation of heat, which damages the cells.
Energy does not travel through any other tissue. Bipolar
instruments can generate temperatures up to 90°C and are
better for controlling bleeding because their effects are
limited to the tissue between the jaws of the instrument.
Advanced bipolar devices can generate heat up to 100°C, and
they have a second aspect that allows the tissue to be cut. Heat
generation with a Nd:Yag laser is less than 50°C.
In patients receiving Vitamin K antagonists like warfarin, the
therapy can be interrupted before surgery. This should occur
approximately 5 days before surgery. For the patient
requiring a cutaneous procedure, the Vitamin K antagonists
for deep vein thrombosis has been continued beyond the
recommended duration of treatment. The warfarin can be
discontinued.
Patients with a coronary stent who are receiving dual
antiplatelet therapy and require surgery should have surgical
procedures deferred for at least 6 weeks after placement of a
bare-metal stent and for at least 6 months after placement of
a drug-eluting stent.
Ultrasonic devices convert mechanical energy, vibration of
the instrument, to generate heat. The energy is transferred to
the tissue between the device's jaws. The heat generated can
reach up to 300°C. Therefore, ultrasonic devices can cut
through tissue and control bleeding. The heat generated at the
tip of the instrument, though, does not dissipate quickly. It
takes approximately 20 seconds for the tips to decrease their
Inguinal hernia repair is an elective procedure, and
nonoperative management is an accepted approach. In this
case, deferring surgery to a later date outside the 6-month
window is recommended. In patients where surgery is a
43
temperature below 100°C. Thus, they can still cause cell
damage long after activation. An ultrasonic device, therefore,
should not be used for dissection or to grab vital tissues (i.e.,
intestines or vessels) unless it has not been activated for more
than 30 seconds.
SSI is to perform the repair laparoscopically. A recent
multicenter VA study prospectively randomized patients with
ventral hernias between open and laparoscopic repairs. The
results showed that laparoscopic repair had significantly
lower incidence of SSI compared with open repair (5.6% vs
23.3%). Overall, the likelihood of developing complications
up to 8 weeks postoperatively was approximately 50% lower
in patients whose hernias were repaired laparoscopically.
5. Versus the traditional landmark technique, the use of
ultrasound guidance in the placement of internal jugular vein
catheters results in
A.
B.
C.
D.
E.
A recent study retrospectively analyzed more than 6000 cases
and showed that the type of surgical hat worn by surgeons had
no relationship to risk of SSI over a 30-day postoperative
period. This study concluded that surgical hats may be chosen
at the discretion of operating room personnel without fear of
increased SSI, and this conclusion is supported by the
American College of Surgeons.
longer cannulation times.
decreased pneumothorax rate.
reduced number of passes to cannulate.
increased hematoma formation.
no difference in overall successful catheter placement.
ANSWER:
Preoperative bowel preparation is used by approximately
12% of surgeons. Ventral hernia repair almost always
involves some degree of bowel manipulation and bowel
injury may occur, particularly in the subset of patients with
extensive adhesions. A study evaluating the accrued data
from the Americas Hernia Society Quality Collaborative
examined more than 3700 ventral hernia repairs and
evaluated whether bowel preparation had a protective effect.
This study showed patients with bowel preparation were
more likely to develop postoperative SSL
C
The use of ultrasound in guiding the localization and
cannulation of the internal jugular vein reduces complication
rates compared with the traditional landmark technique.
Overall, greater successful catheter placement is achieved
with ultrasound guidance. Inadvertent cannulation of the
carotid artery and hematoma formation are reduced when
using ultrasound visualization. Additionally, reduced number
of passes to cannulate, greater success with initial attempt,
and shorter time to successful cannulation are observed with
ultrasound use. There is no statistically observed difference
in the incidence of pneumothorax between the 2 techniques.
Multiple clinical trials demonstrated no difference in SSI
rates between clipping and shaving when performed at the
time of the operative procedure.
7. A 47-year-old woman is admitted to the intensive care unit
after a complex incisional herniorrhaphy with mesh. She has
a history of Crohn disease that required a right
hemicolectomy and ongoing azathioprine and adalimumab
support. On postoperative day 4, she develops profuse
diarrhea associated with a white blood cell count of
28,000/mm3 (3600-11,200/mm3). With fluid support, she
remains hemodynamically normal and is now afebrile.
Investigation for Clostridium difficile identifies a strain
positive for both toxins A and B (BI/NAP 1/027). Which of
the following statements is true regarding her care?
6. Which of the following strategies will have the greatest
impact on preventing postoperative surgical site infection for
ventral hernia repair?
A. Removal of abdominal hair with clippers versus shaving
B. Surgeon use of bouffant hair covering versus skull cap
C. Perioperative mechanical versus oral antibiotics bowel
prep
D. Use of biologic mesh versus artificial mesh
E. Laparoscopic versus open repair
ANSWER:
A. She is at risk of multiorgan failure.
B. Treatment with intravenous vancomycin and
metronidazole is indicated.
C. Antibiotic therapy should continue until toxin assays are
negative.
D. Removal of the new mesh is required to prevent
necrotizing fasciitis.
E. This bacterial strain is the least virulent of the known C.
difficile strains.
E
Surgical site infection (SSI) is one of the most significant
postoperative complications after ventral hernia repair and
can increase the risk of recurrent hernia by at least 3-fold.
Although the surgical community has made significant
improvements in the incidence and treatment of SSIs,
elimination of these events remains challenging due to their
multifactorial nature. Although patient risk factors (obesity,
smoking, and diabetes) for SSI remain beyond the surgeon's
control, the surgeon can and should control certain aspects of
the operation to minimize risk of SSL Perhaps the most
important choice the surgeon can make to minimize risk of
ANSWER:
44
A
Ctostridium difficile colitis is an increasingly frequent
postoperative complication Although long recognized as a
consequence of specific or prolong antibotic use.
asymptomatic C. difficile carrier status is now a major
contributor to out-of-hospital infections, and there has been a
significant spike in nursing home outbreaks Community
carrier status is also a factor in the nearly 20% recurrence rate
Pateints with inflammatory bowel disease (IBD; both Crohn
disease and ulcerative colitis) are particularly vulnerable to
C. difficile colitis and its complications,
C. Extension of antimicrobial prophylaxis to 24 hours
D. Smoking cessation 4 to 6 weeks before surgery
E. Optimization of preoperative HbAlC
ANSWER:
D
Surgical site infections (SSIs) are common, costly, morbid,
and, in an estimated 60% of cases, preventable. An isolated
SSI is associated with, on average, nearly a 10-day increased
length of stay and more than $20,000 in costs during the index
admission. Several, evidence-based guidelines exist to help
decrease rates of SSIs. Risk factors for SSIs can be divided
into modifiable (e.g., smoking status, weight/BMI, nutritional
status) and nonmodifiable (e.g., age, sex, historic infections)
patient factors as well as extrinsic factors (e.g., emergency
procedure, blood transfusions, breach in sterile technique).
Prehospital interventions include preoperative chlorhexidine
bathing (unless part of a decolonization protocol), smoking
cessation, blood glucose control, methicillin-resistant
Staphylococcus
aureus
(MRSA)
screening
and
decolonization, and bowel preparation.
Hospitalized patients with concurrent C. difficile infection
and active IBD are known to have at least a 4-fold risk of
mortality compared with patients with either C difficile
infection or IBD alone. Prior antibiotic exposure#
immunosuppression with biologic agents, and gastric acid
suppression therapies amplify the risk. Further a subset of
IBD patients in remission have a higher carrier rate than the
general population, unrelated to antibiotic exposure or
immunosuppression,
Azathioprine
6-mercaptopurine,
methotrexate, and infliximab are all associated with increased
C. difficile in IBD patients, particularly when the patient is
taking 2 or more agents, Mortality due to multiple organ
failure is high# even with aggressive treatment,
Smoking cessation 4 to 6 weeks before elective surgery
decreases SSIs. This is especially true when an implanted
material or device is part of the procedure. A full bowel
preparation, including mechanical and oral antibiotic
regimen, is recommended for all colectomies but not for
ventral hernia repairs. Although blood glucose optimization
is recommended, reducing the HbAlC does not reduce SSIs.
MRSA screening and decolonization can be of benefit;
however, this requires strict adherence to bundles, otherwise
they are not effective.
Several C. difficile species express A and B toxins* One
especially virulent species is the BI/NAP1/027 clone that
produces both toxins faster and in greater quantities
compared with other clones. These clones are also capable of
producing a binary toxin that leads to increased adherence of
cytotoxic clostridial species to epithelium and is resistant to
fluoroquinolones, levofloxacin, and moxifloxacin.
As a result, this strain is harder to treat and especially
virulent. In many areas of the United States, BI/NAP 1/027
accounts for upward of 50% of all recovered strains, Oral
vancomycin is first-line therapy for severe and complicated
C. difficile infection in IBD patients. Vancomycin enemas
may be used if oral intake is not possible. Intravenous
metronidazole may be added but is significantly less
effective. Alternatives include fidaxomicin, a new
macrocyclic antimicrobial that has 8 times the in vitro activity
compared with vancomycin against clinical C. difficile
isolates but is expensive. It is recommended that treatment be
continued for 10 days. If active colitis is not resolved or
infection is recurrent despite vancomycin or fidaxomicin,
fecal microbiota transplant should be considered.
Monoclonal antibodies and immunoglobulin therapies are
emerging as potential adjuncts.Removal of the mesh in this
case should not be necessary.
Hospital interventions shown to be of benefit include
maintaining normothermia and warming if necessary,
avoiding hyperglycemia, avoiding removal of hair with a
razor, using an alcohol-containing preparation unless
contraindicated, properly administering preoperative
antibiotics, and using a wound protection device (colorectal
cases).
Antibiotic ointment may be of benefit in spine, joint, and
cataract surgery, but it is not recommended for all cases.
Proper antibiotic administration involves the appropriate
agent, dosing, and timing. Antibiotic selection will depend on
the procedure and the involved potential pathogens. Ideally,
antibiotics should be administered within 1 hour of incision
(2 hours for vancomycin or fluoroquinolones) and be redosed
based on the pharmacokinetics or after and estimated blood
loss of 1500 mL. No evidence supports antibiotic
administration after incision closure except in the setting of
implanted breast reconstruction, cardiac surgery, and joint
arthroplasty.
8. A 45-year-old woman with multiple past abdominal
surgeries requires an abdominal wall reconstruction for
recurrent ventral/incisional hernia. The surgical plan is for a
retrorectus repair with a synthetic mesh. What reduces
surgical site infections?
A. Preoperative mechanical bowel preparation
B. Removal of hair from the surgical site
9. A 48-year-old man with diabetes presents with a
malodorous ulcer on the sole of his right foot over the head
45
of the first metatarsal head. No bone is visible. He has been
treated with local wound care. He is currently taking broadspectrum antibiotics. His white blood cell count is
12,000/mm3 and his HbAlC is 9%. He is febrile and
tachycardic. He has a right palpable dorsalis pedis pulse. The
next step in his management should be
A.
B.
C.
D.
E.
to his methadone, his postoperative pain is managed with a
short course of oral nonsteroidal anti-inflammatory drugs
without additional opioids. He was started on efavirenz, a
nonnucleoside reverse transcription inhibitor, the week
before surgery. At his 2-week followup appointment, he
complains of a 4-day history of nausea, vomiting, and
diarrhea with associated restlessness, diaphoresis, and
tachycardia. Otherwise, his physical exam, imaging, and
routine labs are unremarkable. CD4 count is 500 cells/mm3
(500-1400/mm3). What is the most helpful blood test in
facilitating his management?
MRI to rule out osteomyelitis.
sharp debridement.
negative pressure wound therapy.
honey dressings.
hyperbaric oxygen treatment.
ANSWER:
A.
B.
C.
D.
E.
B
Clinical practice guidelines for diabetic foot infection were
published in 2016 by the Society for Vascular Surgery in
collaboration with the American Podiatric Medical
Association and the Society for Vascular Medicine. No
debridement technique shows superiority, and initial sharp
debridement is recommended based on patient tolerance,
expertise, supplies, and cost-effectiveness. Urgent surgical
intervention should be performed for foot infection involving
abscess, gas, or necrotizing soft tissue infection.
Thyroid-stimulating hormone
Gamma-glutamyl transferase
Serum methadone trough level
Procalcitonin level
Helicobacter pylori level
ANSWER:
C
Both opioid-use disorder and HIV/AIDS are common
diagnoses. They are often, as in this patient, seen together.
Opioid agonist therapy, such as methadone and
buprenorphine, is extremely effective treatment for opioiddependent patients. Highly active antiretroviral therapy is
now widely available and reduces both morbidity and
mortality in patients with HIV/AIDS. The potential for drug
interactions between both categories of medication are many,
and knowledge of their metabolism is crucial.
Adjunctive wound therapy options are recommended if a
diabetic foot ulcer fails to decrease in size by at least 50%
after a minimum of 4 weeks of standard wound therapy.
Negative pressure wound therapy is one wound management
approach suggested for these nonhealing or chronic diabetic
foot wounds. Diabetic patients should have baseline anklebrachial index (ABI) measurements performed at the age of
50. Annual vascular examination is recommended for
diabetics including foot examination, ABI, and toe pressures.
Methadone, a full opioid agonist, is dosed orally once a day.
Its metabolism is complicated, with plasma concentrations
following a biexponential curve. It undergoes oxidative
metabolism of the cytochrome p450 system in the liver. There
is significant interindividual variability in methadone's
metabolism, possibly due to variability in the activity and
expression of this enzyme system as well as protein-binding
displacement and stereospecific binding.
The goal of an ideal wound dressing is to maintain a moist
wound bed, control exudate, and avoid maceration of
surrounding intact skin. Wet-to-dry dressings were a standard
mechanism for debridement, but they have fallen out of favor
because the debridement is nonselective and may harm viable
tissue while removing necrotic tissue. Furthermore, when
wet-to-dry dressings are performed correctly, removing the
dry dressings can be painful. A trial showed that honey
dressing was more effective in healing diabetic foot ulcers
than wet-to-dry dressings and decreased the time to healing.
Nonnucleoside reverse transcriptase inhibitors (NNRTIs),
such as efavirenz, are highly effective antiretrovirals. Their
metabolic activity is dependent on their plasma
concentrations, which remain in equilibrium with the
intracellular concentrations. NNRTIs share metabolic
pathways with methadone. Efavirenz both induces and
inhibits several enzymes in the cytochrome p450 complex,
resulting in a 50% decrease in bioavailability of methadone
within several weeks of initiation of efavirenz therapy. As
such, the start of efavirenz treatment has precipitated
symptoms of opioid withdrawal in this patient, despite no
change in his methadone dosing. A low serum methadone
trough level will confirm this and allow for appropriate
replacement therapy or reconsideration of the use of
efavirenz.
Plain radiographs of the foot are not adequate to diagnose
osteomyelitis secondary to their low sensitivity and low
specificity. If additional imaging is desired, especially to
evaluate for abscess, MRI is the study of choice and can help
identify the presence of osteomyelitis.
10. A 26-year-old man undergoes uneventful laparoscopic
preperitoneal repair of bilateral inguinal hernias with mesh.
He is HIV-positive and receives maintenance methadone
treatment for opioid dependence. After discussion with his
primary care provider and methadone prescriber, in addition
This patient lacks any symptoms suggestive of thyroid
disease, liver disease, or Helicobacter pylori infection.
46
Elevation of procalcitonin, an acute phase protein, is highly
specific in differentiating infection from other inflammatory
conditions in patients with autoimmune disease. Its
determination in this patient would not change his care or aid
in diagnosis.
cognitive
dysfunction,
including
disorientation,
hallucination, and memory and attention disturbances, all of
which can complicate postoperative care and increase length
of stay.
A recent prospective study examined risk factors for
postoperative delirium in patients 75 years and older
undergoing major abdominal surgery. With an overall
incidence of 24%, postoperative delirium was associated with
a higher American Society of Anesthesiologists (ASA) status
(ASA class III-IV), impaired mobility, and use of opioids.
Even patients treated with opioid-like analgesics (e.g.,
tramadol) are at risk of postoperative delirium. In this study
of 60 patients who received postoperative tramadol, 22
(33.6%) developed postoperative delirium compared with 6
of 58 (10.3%) of patients who did not (p = .0008). On
multivariate analysis, duration of the procedure and use of
propofol during the procedure did not affect the development
of postoperative delirium. Use of a bladder catheter during
abdominal surgery in geriatric patients is not associated with
the development of delirium.
11. After a routine laparoscopic sigmoidectomy for cancer in
an otherwise healthy patient when is the appropriate time to
advance a patient’s diet to solid food?
A.
B.
C.
D.
E.
After first bowel movement
After passage of flatus
When bowel sounds return
Once the patient is awake and alert
After the patient tolerates liquids
ANSWER:
D
Early (<24 hours) oral feeding before the return of bowel
function after gastrointestinal surgery is supported by several
studies and is recommended by the Society of Colon and
Rectal Surgeons and the Society of American Gastrointestinal
and Endoscopic Surgeons in the recent publication of clinical
practice guidelines for enhanced recovery after colon and
rectal surgery.
13. A 23-year-old man is admitted to the intensive care unit
after a damage control laparotomy for traumatic injuries to
his liver and spleen. The patient has an open abdomen and
requires return to the operating room. Which of the following
is associated with higher rates of primary fascial closure?
An early prospective, randomized controlled trial showed no
difference in nasogastric tube insertion between patients
whose diets were advanced on postoperative day 1 compared
with at the time of intestinal function. In addition, hospital
stays were shorter for patients in the accelerated pathway by
nearly 2 days without increasing readmissions or
complications. In a meta-analysis of 7 randomized clinical
trials comparing early with traditional oral feeding, the early
oral feeding group had a shorter length-of-stay (difference of
1.58 days; p <.009) and reduced risk of total postoperative
complications (relative risk 0.70; p = .04). The early oral
feeding group had no increased risk of vomiting, insertion of
nasogastric tubes, anastomotic dehiscence, wound infection,
or pneumonia.
A.
B.
C.
D.
E.
ANSWER:
Foley catheterization.
opioid analgesia.
American Society of Anesthesiologists class I-II.
surgical procedure lasting more than 4 hours.
use of propofol during the procedure.
ANSWER:
B
This scenario is frequently encountered. Severely injured or
septic patients may not tolerate an abdominal closure at the
index operation and may require resuscitation in an intensive
care setting before they are able to tolerate further procedures
and anesthesia. Delays in abdominal closure, however, can
predispose the patient to the development of enteroatmospheric fistulas and insensible as well as sensible fluid
losses from the relatively exposed peritoneal cavity.
12. In geriatric patients undergoing elective abdominal
surgery, postoperative delirium is associated with
A.
B.
C.
D.
E.
Delayed return to the operating room by at least 48 hours
Volume resuscitation with 3% hypertonic saline
Early diuresis with a furosemide drip
A filling pressure of less than 10 mm Hg
Continuous renal replacement therapy after initial
damage control laparotomy
Delaying return to the operating room decreases the
likelihood of primary fascial closure. The first return to the
operating room should be as soon as possible (within 24
hours) but no later than 48 hours.
The use of intravenous 3% hypertonic saline in patients with
an open abdomen is associated with increased rates of
primary fascial closure. The likely etiology of this success is
related to the development of an osmotic gradient favoring
the removal of intestinal edema into the intravascular space.
Conversely, forced diuresis with a loop diuretic drip is not
B
Postoperative delirium is the most common complication of
major abdominal surgery in older patients. It manifests as
47
associated with increased rates of fascial closure, despite the
inherent logic of its application. Similarly, no specific
evidence suggests that early institution of renal replacement
therapy or keeping a patient's central venous pressures below
a certain level help with the closure.
B. Nicotine inhibits the proliferation of fibroblasts and
macrophages.
C. Biofilm is a protective coating on healing wounds.
D. Hypoglycemia delays wound healing.
E. Topical antimicrobial agents cannot induce bacterial
resistance.
14. Which of the following statements is true for enteral
nutrition in the critically ill patient?
ANSWER:
A. Total caloric intake for the obese patient is 25 to 30
kCal/kg.
B. Growth hormone supplementation increases survival in
ventilated patients.
C. Postpyloric feedings result in decreased mortality
compared with gastric feedings.
D. Total protein intake should be 2 to 2.5 g/kg of ideal body
weight per day.
E. The routine use of probiotics improves patient survival.
ANSWER:
B
Wound healing is affected by many environmental factors.
Adequate oxygenation is critical to healing wounds. The
presence of anemia does not necessarily decrease tissue
oxygenation, because this is also dependent on cardiac
output, capillary permeability, and vasodilation. Nicotine is a
vasoconstrictor that impairs oxygen delivery, increases
platelet adhesion, and inhibits proliferation of red blood cells,
fibroblasts, and macrophages.
The presence of diabetes mellitus has a profound effect on
wound healing. Hyperglycemia can inactivate enzymes and
alter the basement membrane so that transfusion of nutrients
is limited. Hyperglycemia makes wounds more prone to
infection and slower to heal.
D
Calculations of nutritional needs include a 25 to 30 kCal/kg
estimate for most critically ill patients. This estimate is not
accurate, however, in extremely thin or morbidly obese
patients, and a lack of standardized recommendations
persists.
Another barrier to wound healing is the presence of biofilm.
This is a collection of bacteria surrounded by a self-produced
polymer matrix. While commonly found in chronic,
contaminated wounds, this is not a normal part of wound
healing and is not protective to the wound base.
Indirect calorimetry may guide nutritional support when
available. One strategy for patients where this is not available
is to provide 65 to 70% of estimated total caloric needs based
on ideal body weight. With sufficient protein (2 to 2.5 g/kg of
ideal body weight), this strategy will promote overall weight
reduction and preservation of lean body mass.
Topical antimicrobial agents target therapy against biofilms,
but there is little evidence that this strategy improves wound
healing rates or outcomes. Bacterial resistance also occurs
with topical antimicrobial agents.
Metabolically active agents were extensively studied in
intensive care unit patients. Interestingly, a large randomized
trial of growth hormone in ventilated patients found no
survival advantage associated with its use. Enteric tube
placement is necessary to provide optimal nutritional support
in ventilated patients. Postpyloric feeding tubes are
associated with a decreased incidence of pneumonia in many
studies, but no difference in intensive care unit length of stay
or mortality has been documented. Although published trials
concur that probiotic use is associated with a decreased
incidence of nosocomial infections and pneumonia, overall
mortality does not decrease. Published data also vary widely
in terms of type of probiotic used and site of application
(small bowel vs stomach). Several studies reported probioticassociated bacteremia and central venous catheter associated
infections, yet others noted a decreased incidence.
16. Which of the following statements is true about
perioperative opiate use?
A. Low-income patients are more likely to overdose on
opiates.
B. Patients treated in teaching hospitals are more likely to
overdose.
C. Hepatic insufficiency is an Independent predictor of
opioid overdose.
D. More than 70% of prescribed opioid pills are not used by
patients.
E. Preoperative pain management with opioids decreases
hospital length of stay.
ANSWER:
D
Opioid use and misuse after surgery or injury is a growing US
healthcare crisis. Appreciating the risk factors for opioid
addiction or perioperative overdose represents essential
surgical knowledge. Preoperative opioid users may have
increased hospital length of stay and infectious
15. Which of the following statements about wound
management is true?
A. Anemia increases wound infection rates.
48
complications. In the orthopedic population, patients report
more postoperative hyperalgesia, decreased quality of life,
and decreased physical function.
Several reports have dispelled assumptions about patient
characteristics that predict opioid dependency or overdose.
Published studies of effects of preoperative opioid use on
postoperative outcomes identified a prevalence of chronic
opioid use to range from 9.2 to 23%. Some studies reported
that chronic users are more likely to be black and less likely
to be commercially insured. Multivariable analysis indicates
that individuals who overdose after surgery are more likely to
be female, older (>60 years old), and from a higher income
quartile (>$35,000 per year). Predictors of postoperative
overdose include a history of substance abuse and preexisting renal insufficiency. Hepatic insufficiency was not
identified as an independent risk factor for overdose.
Although there is no statistical difference in likelihood of
perioperative overdose in the type of hospital (e.g., rural,
urban, teaching or nonteaching), opioid overdoses are more
likely in larger hospitals.
Figure 17.1. The Mallampati Classification
pillars to class IV when only the hard palate is visualized. In
addition to determining the Mallampati classification, the
physician should recognize other risk factors that lead to
difficult intubation and should prepare accordingly. These
risk factors include obesity, neck immobility, interincisor
distance less than 4 cm in adults, large overbite, inability to
shift the lower incisors in front of the upper incisors, and a
thyromental distance less than 6.5 cm. The thyromental
distance is measured from the thyroid cartilage to the tip of
the chin. A history of difficult intubation is one of the most
important risk factors for future difficult intubations. When a
difficult airway is anticipated, preparation for alternative
approaches to direct rigid laryngoscopy such as fiberoptic,
video laryngoscopy, blind nasal intubation, or tracheostomy
should be considered.
In spite of growing understanding about the negative effect of
perioperative opioid use on outcomes, analysis of prescribing
habits after elective general surgery procedures suggests that
clinicians continue to prescribe large numbers of opioid pills.
One recent study determined that more than 70% of the
prescribed opioid pills (ranging from 15-100) were not taken
by patients who were discharged home; in this analysis, less
than 2% of the patients requested refills, suggesting that
opioids were being overprescribed. Because opioid use is a
potentially modifiable behavior, controlling how much
medication patients receive could mitigate some of the
postoperative complications associated with opioid use.
18. A 70-year-old woman with congestive heart failure is on
warfarin for a history of atrial fibrillation. She presents to the
emergency department with a small bowel perforation.
Which of the following is a risk factor for a stroke in this
patient?
17. When evaluating an adult for possible orotracheal
intubation, what is the best risk factor for predicting a difficult
intubation?
A.
B.
C.
D.
E.
A. Inability to move the lower incisors in front of the upper
incisors
B. BMI greater than 27
C. Previous cervical spine injury with normal mobility
D. Interincisor distance of 5 cm
E. Thyromental distance of 7 cm
ANSWER:
Age of 70 years old
Female sex
Need for urgent surgery
Congestive heart failure
Sepsis
ANSWER:
D
The use oral anticoagulation agents are increasing nationwide
for a myriad of conditions including Atrial fibrillation stent
placement and thromboembolic event.
A
As such surgeons need to understand which patients require
perioperative anticoagulation and have an increased risk of
perioperative thrombotic events with cessation of
anticoagulation. In patients with a high stroke risk, failure to
resume anticoagulation in a timely fashion can be associated
with perioperative thromboembolic complications. One
commonly used tool to assess the risk of stroke is the
CHADS2 score
A critical component of obtaining a secure airway is the
evaluation of the airway. This evaluation is vitally important
when considering administration of agents that induce apnea
during the intubation process. The Mallampati classification
(figure 17.1) is based on the structures that can be visualized
with maximal oral opening and tongue protrusion while the
patient is in the sitting position. Classification ranges from
class I visualization of the soft palate, fauces, uvula, and
49
[table 18.1; congestive heart failure (1 point), hypertension (1
point), age older than 75 (1 point), diabetes mellitus (1point),
history of stroke transient ischemic attack (2 points). The
presence of clinical conditions can be used to estimate the risk
of perioperative and general stroke risks. The described
patient has congestive heart failure as her only risk factor and
has a CHADS2 score of 1 with a relatively lower overall
perioperative risk for stroke. This patient can safely undergo
surgery without a heparin bridge.
Risk factor
1
CHA2DS2VASC
score
points
1
1
1
Age >75 years
1
2
Diabetes mellitus
1
1
Stroke/transient Ischemic
attack/thromboembolism
2
2
Vascular disease
-
1
Age 65-74 years
-
1
Sex category (i.e., female)
-
1
Maximum score
6
9
Congestive
failure/left
dysfunction
Hypertension
CHADS2
score points
heart
ventricular
B.
C.
D.
E.
Intravenous phosphate
Intravenous antibiotics
Intravenous steroids
Plasmapheresis
ANSWER:
E
Patients with myasthenia gravis are at risk of hypoventilation
due to diaphragmatic weakness. The etiology of this disease
is autoimmune, characterized by antibodies to nicotinic
acetylcholine receptors at the neuromuscular junction.
Chronic treatment includes immunosuppression (e.g., with
corticosteroids) and anticholinesterase medications. Several
medications can contribute to worsening of myasthenia,
including antibiotics and neuromuscular blockers that could
have been used during surgery to treat this patient for her
perforated diverticulitis. Her respiratory acidosis in the
perioperative period is best managed acutely with intubation.
Plasmapheresis is then used to treat the myasthenia crisis.
Because she has a normal-appearing wound and normal renal
function, compartment syndrome is unlikely. Hypophosphatemia, which can cause respiratory insufficiency, is a
concern in chronically malnourished patients and is unlikely
to be a concern in this patient who presented acutely.
Intravenous antibiotics would treat worsening sepsis, which
is unlikely to be the etiology of her deterioration given recent
source control, normal chemistries, unchanged white blood
cell count, and an unremarkable chest x-ray. Intravenous
steroids are not helpful in reversing respiratory depression
from myasthenia.
Table 18.1. Comparison of the CHADS2 and CHA2DS2VASc scoring systems. Note. CHADS2 or CHA2DS2-VASc
score, documenting risk factors for stroke: History of
congestive heart failure, hypertension history; age >75 (or age
>65 years associated with one of the following: diabetes
mellitus, coronary artery disease, or hypertension); diabetes
mellitus; stroke or transient ischemic attack or
thromboembolism history; vascular disease history; sex
category.
20. A 40-year-old man is undergoing elective open distal
pancreatectomy. Perioperative epidural analgesia is likely to
increase
New oral anticoagulants in patients with nonvalvular atrial
fibrillation:
A.
B.
C.
D.
E.
19. A 70-year-old woman with a long-standing history of
myasthenia gravis presents with peritonitis and
pneumoperitoneum secondary to perforated sigmoid
diverticulitis. On the evening after an emergency Hartmann
procedure, she is somnolent and demonstrates hypoxia, with
an arterial blood gas with a pH of 7.25, PaCO2 = 62 mm Hg,
PaO2 = 60 mm Hg. There is no change after administration
of naloxone and neostigmine. Her blood pressure and heart
rate are normal. Her abdomen is soft, and she has a
colostomy. Her basic metabolic panel is normal, and she has
a persistent leukocytosis but normal hemoglobin. Chest x-ray
after intubation is unremarkable. After she is stabilized, what
intervention should be performed to address the likely
etiology of her respiratory failure?
oral opiate use.
perioperative mortality.
urinary tract infection.
episodes of perioperative hypotension.
rates of postoperative ileus.
ANSWER:
D
The rationale for use of thoracic epidural anesthesia for open
cancer procedures is to optimize postoperative pain control
and decrease intravenous narcotic use. However, compared
with patients receiving intravenous opioids, those managed
with an epidural have increased episodes of perioperative
hypotension attributable to local anesthetics. This is because
of the sympathetic blockade that decreases preload and
afterload. Given its analgesic effects, epidural placement is
likely to decrease, not increase, intravenous and oral opiate
A. Decompressive laparotomy
50
use. Although it is possible that decreased opioid use can in
turn decrease complications and mortality, this finding is not
consistently demonstrated. Epidural anesthesia does not
directly increase rates of urinary tract infection. Epidural use
is likely to decrease or not affect, rather than increase,
postoperative ileus.
pacemaker. Using a bipolar instrument will also reduce this
chance but will not eliminate it.
An ultrasonic device does not pass electrical energy through
the patient and does not require a dispersion pad for its use.
Instead mechanical energy (vibration) creates heat up to
300°C, which dissects the tissue and causes coagulation.
Because electrical energy does not pass through the patient
with such devices, it is the best choice for this patient to avoid
electrical interference with her pacemaker.
21. Six years ago, a 62-year-old woman had a quadruple
coronary artery bypass graft with a cardiac pacemaker placed
through her left subclavian vein. The pacemaker sits just
below her clavicle and above her breast tissue. She now
presents with stage II right breast cancer, and she has elected
to undergo a modified radical mastectomy. You are
concerned about disruption of her cardiac pacemaker with the
use of surgical electricity, because she is pacemaker
dependent Which of the following will most likely decrease
the risk of electromagnetic interference of the pacemaker
during the procedure?
A.
B.
C.
D.
E.
22. For an elective clean-contaminated case, which of the
following statements regarding the guidelines for prevention
of a surgical site infection is true?
A. Antibiotic wound irrigation lowers surgical site infection
rates.
B. Antibiotic powders in surgical wounds at closure reduce
surgical site infection rates.
C. Glucose should be controlled intraoperatively with a goal
of less than ll0 mg/dl.
D. Skin should be prepared with iodine-based agents unless
contraindicated
E. Antibiotics do not need to be continued after skin
closure.
Using monopolar electricity only on blend mode
Placing the dispersion pad on the right arm
Placing a magnet on the pacemaker
Reprogramming the pacemaker into synchronous mode
Using ultrasonic shears for the dissection
ANSWER:
ANSWER:
E
E
New guidelines were published in 2017 regarding preventing
surgical site infections in clean and dean-contaminated cases.
The new guidelines include stopping antibiotics after skin
closure, meaning that prophylaxis does not need to extend a
full 24 hours as previously advised. The other guidelines
include skin preparation using alcohol-based solutions unless
otherwise contraindicated, maintaining perioperative glucose
control with a goal of less than 200 mg/dL, and maintaining
normothermia. The use of antibiotic wound irrigation and
antibiotic powders does not improve surgical site infection
rates.
The safe use of electrical devices in the operating room
includes not only the surgical energy devices like the
monopolar and bipolar instruments but also the maneuvers to
avoid an operating room fire or interference with other
electrical devices like a cardiac pacemaker or ventricular
assist device. If the patient has a pacemaker in place, it is
important to know whether the patient is pacemaker
dependent. If not, then the device can simply be shut off for
the procedure. For most cardiac pacers, this can be done with
a magnet. If she is pacemaker dependent, the device must be
left on for the procedure. Pacemaker dependence means that
the device will fire because the patient's own rhythm will not
cause sufficient ventricular contraction. Therefore, putting
the pacemaker on synchronous mode means that it will fire or
"assist" only based on the patient's rhythm, which is
inadequate.
Items 23-25
Each lettered response may be selected once, more than once,
or not at all.
A. Direct Factor Xa inhibitor
B. Inhibits the activity of Vitamin K-dependent enzymes
C. Nonreversible cyclo-oxygenase (COX)-l and COX-2
inhibitor
D. Reversible phosphodiesterase inhibitor
E. Competitive direct inhibitor of thrombin
For pacemaker-dependent patients, any electrical current via
the electrical cord of the Bovie or the transfer of energy from
the device to the dispersion pad should not cross paths with
the pacemaker device. As such, simply putting the device on
blend mode, which may reduce the overall energy flowing to
the Bovie tip and into the tissue, will not avoid electrical
disruption of the pacemaker.
23. Aspirin
24. Dabigatran
Placing the dispersion pad away from the pacemaker on the
patient's right arm or on the patient's right thigh will reduce
the amount of energy passing near the pacemaker but it will
not eliminate all current that may interfere with the
25. Apixaban
51
ANSWERS:
C. water-soluble contrast study.
D. upright abdominal x-rays.
E. broad-spectrum antibiotics.
C, E, A
Atrial fibrillation is the most common cardiac dysrhythmia in
the United States, with an anticipated incidence of 6 to 12
million older Americans by year 2050. Warfarin reduces the
stroke risk by two-thirds and is commonly prescribed in atrial
fibrillation. Warfarin, however, has significant limitations
because of a narrow therapeutic window. Approximately onethird of patients with increased risk for stroke are not started
on warfarin or discontinue it after initiation because of side
effects or medication nonadherence.
ANSWER:
Percutaneous endoscopy gastrostomy (PEG) is a good
solution for long-term enteral nutrition in patients who cannot
swallow. In adults, PEG is commonly placed for patients with
acute stroke, central nervous system trauma, and oncologic
and neurodegenerative diseases. Tube dislodgment, however,
accounts for up to one-third of PEG tube failures. If
dislodgement occurs before the PEG tract completely
matures, the stomach may separate from the abdominal wall
and cause leakage of feedings and gastric contents into the
peritoneal cavity. The most important step is to immediately
stop feeding and verify that the tube remains in the stomach
by performing a water-soluble contrast study. An exploratory
laparotomy is necessary if the patient has obvious signs of
peritonitis or the contrast study demonstrates peritoneal
contrast spillage. Upright abdominal x-rays may show
residual air instilled during the original PEG placement.
Conversely, the absence of free air under the diaphragm does
not rule out tube malposition. Once proper tube position is
confirmed by the contrast study, providers may treat exit site
infection with either antibiotics, bedside drainage, or a
combination of these.
Aspirin reduces stroke risk by 20% and is used in patients
with a contraindication to warfarin. Aspirin reversal with
platelet transfusion is often performed in cases of lifethreatening hemorrhage. Desmopressin when given as an
intravenous bolus over 30 minutes increases von Willibrand
Factor and Factor VIII activity within 1 hour and increases
platelet activity. The combination of platelet transfusion and
desmopressin in one retrospective study did not show a
decrease in intracranial hemorrhage progression or mortality.
No randomized controlled trials of desmopressin in aspirin
reversal have been carried out, although guidelines suggest
consideration of desmopressin use in acute hemorrhage and
intracranial hemorrhage.
Direct oral anticoagulants are increasingly prescribed for
atrial fibrillation because of their predictable anticoagulant
activity, short half-life, and minimal drug-drug interactions
(table 23-25.1). An example of a reversible
phosphodiesterase inhibitor is cilostazol, which is commonly
used to treat claudication.
Dabigatran
Rivaroxaban
Apixaban
Edoxaban
Target
Thrombin
Factor Xa
Factor
Xa
Factor Xa
Half-life
(hours)
12-17
5-9
11-13
(in
elderly)
12
10-14
Peak plasma
1
2-4
3-4
1-2
80
33
27
50
35
>90
87
55
concentration
(hours)
Renal
clearance (%)
Protein
binding (%)
C
27. Four hours after pneumatic dilation of the esophagus to
treat achalasia, a 72-year-old man presents with moderate
chest pain and tachycardia. A Gastrografin esophagogram
demonstrates an uncontained leak in the distal third of the
esophagus with minimal mediastinal contamination. After
resuscitation and intravenous antibiotics, the next step should
be
A.
B.
C.
D.
parenteral nutrition.
endoscopic closure with clips.
placement of a covered stent with drainage.
right thoracotomy, closure of the perforation, and pleural
patch.
E. esophageal exclusion, cervical esophagostomy, and
gastrostomy tube.
Table 23-25.1. Properties of non-Vitamin K antagonist oral
anticoagulants.
ANSWER:
26.
A 78-year-old man with dysphagia underwent
percutaneous endoscopic gastrostomy (PEG) 10 days ago.
Overnight, the patient became confused and pulled on the
PEG tube. The patient's nurse noted that marking on the tube
now reads 1.5 cm. It was previously at 3 cm length. He now
complains of abdominal pain, redness around the PEG site,
and drainage. The next step in management is
C
Benign esophageal perforation Is a highly morbid condition
requiring urgent recognition and Intervention. Compared
with iatrogenic perforation, spontaneous esophageal
perforation (Boerhaave syndrome) is associated with a higher
mortality because of the delay in diagnosis. Regardless of
etiology, the condition was historically treated with
aggressive operative intervention ranging from thoracotomy
with direct repair and patching to esophageal exclusion and
cervical esophagostomy. however, despite Improvements in
A. exploratory laparotomy.
B. bedside incision and drainage.
52
surgical technique and critical care, the reported
postoperative leak rate remains between 30 and 40%.
Because reported experience with esophageal perforation has
Increased, less invasive options have become available,
depending on the clinical circumstance.
smaller (<2 cm) tears, whereas larger defects require stent
placement or sutures.
28. A 70-year-old man takes warfarin for adjunctive
management of atrial fibrillation and has severe congestive
heart failure at baseline. He will require urgent operative
intervention for perforated sigmoid diverticulitis associated
with diffuse peritonitis and a large quantity of
pneumoperitoneum noted on CT imaging. His international
normalized ratio is 4.0 (0.8-1.2). In addition to the
administration of Vitamin K, which anticoagulation reversal
regimen is best for this patient?
Nonoperative management may be appropriate in highly
selected situations and seems to be moat applicable to
iatrogenic perforations. Three criteria are typically used for
nonoperative management of esophageal perforations: mild
symptoms, perforation contained within the mediastinum and
draining back into the esophagus, and minimal evidence of
sepsis. If all 3 of these criteria are met, the patient can be
reasonably treated with hyperalimentation, intravenous
antibiotics, and cimetidine or proton pump inhibitors.
A.
B.
C.
D.
Fresh frozen plasma
Cryoprecipitate
3-factor prothrombin complex concentrate
3-factor prothrombin complex concentrate
recombinant Factor Vila
E. 4-factor prothrombin complex concentrate
A hybrid treatment of free esophageal perforations is now
favored. Current algorithms use on esophageal stent to seal
the perforation and a drainage procedure to control
mediastinal contamination. The stent is placed
endoscopically, avoiding the need for thoracotomy. The
clinical applications of esophageal stents have expanded with
increased use to include spontaneous perforations, iatrogenic
perforations, anastomotic leaks, and cancer-associated
perforations. The technique of stent placement involves
oversizing with a 21- to 25-mm diameter self-expanding,
covered stent in the longest possible length that does not
cover the gastroesophageal junction or the arytenoid fold of
the posterior oropharynx. The stent is placed while the patient
is under general anesthesia, and the area is adequately drained
at the same operation by video-assisted thoracoscopy, imageguided percutaneous drainage, or laparoscopy. A contrast
esophagogram is performed 48 to 72 hours after stent
placement to ensure that the leak has been sealed. The stent
is usually removed within 14 days to minimize complications
of stent migration, tracheoesophageal fistula, or
aortoesophageal fistula.
ANSWER:
plus
E
Warfarin is a Vitamin K antagonist and common oral
anticoagulant. When patients who take this medication
develop life-threatening hemorrhage or require urgent
operations or invasive procedures, rapid reversal of the
anticoagulant effect is needed. In addition to Vitamin K,
historically fresh frozen plasma and, less commonly,
cryoprecipitate were the only options available for reversal.
Large volumes of these blood products are required to
achieve adequate reversal, which is problematic for patients
who cannot tolerate rapid infusion of large volumes of
colloid, such as patients with congestive heart failure.
Additionally, the time required to achieve reversal can be
lengthy with the use of these blood products.
Several factors preclude the hybrid approach: injury longer
than 6 cm, injury that traverses the gastroesophageal junction
or proximal cervical esophagus, or injury associated with a
leak in the gastric conduit after esophagectomy. These
injuries favor surgical repair. The most common
complication is stent migration, which can be mitigated by
using as long a device as possible and removing it within 2
weeks. Results of the hybrid approach have been positive in
terms of leak occlusion, median hospital stay, total hospital
charges, and survival. In a propensity-matched comparison of
the hybrid technique with primary surgical repair, esophageal
stent placement was as effective and resulted in a shorter
length of stay, lower morbidity, and lower cost.
More recently, prothrombin complex concentrates (PCCs)
have become available for reversal of the anticoagulant effect
of warfarin. Three-factor PCC contains consistent quantities
of FactorsII, IX, and X, but only trace quantities of Factor
VII. Three-factor PCC may not completely reverse warfarin
and can be augmented with recombinant activated factor VII
(rFVIIa), which allows for complete reversal. Four-factor
PCCs contain consistent quantities of Factors II, IX, X, and
VII. Four-factor PCCs also contain complimentary quantities
of critical anticoagulant enzymes such as protein C, protein
S, and antithrombin HI, as well as heparin. Therefore, 4factor PCC achieves a more balanced replacement of the
Vitamin K-dependent enzymes and may prevent untoward
unopposed thrombosis during administration.
Other less invasive options are available to seal esophageal
perforations, including endoscopic clips, suturing, and fibrin
sealants. Experience with these options is limited, and none
seems to offer any advantage over endoprostheses. Based on
the limited studies, clips are currently recommended only for
When 4-factor PCC is compared with fresh frozen plasma for
reversal of warfarin before urgent procedures, 4-factor PCC
is effective and superior to fresh frozen plasma for rapid
international normalized ratio (INR) reversal and effective
hemostasis. When 4-factor PCC is compared with 3-factor
53
PCC, a more reliable correction of the INR is seen with 4factor PCC. Finally, when 4-factor PCC is compared with 3factor PCC + rFVIIa for warfarin reversal after traumatic
hemorrhage, 4-factor PCC is associated with a less severe
decrease in INR, a significant reduction in deep venous
thrombosis rates, and a trend toward reduced mortality.
preoperative patient risk factors, it can calculate the risk of
death, overall complication rate, pneumonia, heart problems,
surgical site infection, urinary tract infection, blood clot,
kidney failure, and estimated length of stay. NSQIP has not
been validated for emergency surgery.
The Eastern Cooperative Oncology Group (ECOG)
Performance Status is a measurement of a patients' activities
of daily living and measures patients' ability
29. What is the best independent predictor of the need to
discharge to a postoperative care facility in elderly patients
undergoing emergency general surgery?
30. A 72-year-old man underwent a Hartmann procedure for
perforated diverticular disease and a pelvic abscess. His
comorbidities included compensated chronic congestive
heart failure and type 2 diabetes controlled by diet and an oral
hypoglycemic agent. He was transiently hypotensive during
the operation but responded promptly to fluid infusion. What
is the most effective strategy to prevent perioperative acute
kidney injury?
A.
B.
C.
D.
American Society of Anesthesiologists classification
Age
Frailty score
National Surgical Quality Improvement Program®
Surgical Risk Calculator
E. Eastern Cooperative Oncology Group performance
status
ANSWER:
A.
B.
C.
D.
E.
C
Frailty is best conceived of as an age-related,
multidimensional state of decreased physiologic reserves,
which is associated with a decrease in resiliency, a loss of
adaptive capacity, and an increase in vulnerability to
stressors. Frailty is closely related to poor health care
outcomes, including outcomes after surgery. Frailty is
thought to be present in 10 to 20% of patients older than 65,
and its occurrence and effects increase with age. In 2010,37%
of all inpatient operations were performed on patients older
than 65. Other than age, promoters of the frail state include
uncompensated single end-organ dysfunction (e.g., kidney
failure, heart failure), chronic infection, and malignancy. Not
surprisingly, frail patients are much more likely to experience
adverse outcomes after surgery.
Furosemide
N-acetyl cystine
Sodium bicarbonate
Low-dose dopamine
Maintenance of euvolemia
ANSWER:
E
Perioperative acute kidney injury (AKI) remains a common
problem for surgical patients and worsens surgical outcomes,
regardless of which outcome is considered. Varying degrees
of AKI are seen in 50% of trauma patients and as many as
50% of patients undergoing aortic or hepatic surgeries. Even
though the diagnosis of AKI may be increasing due to the
increased sensitivity of the tools used to identify it, to date,
there is no consistently effective strategy that is renal
protective. This is because the etiology of AKI is
multifactorial, and the etiology varies depending on the
underlying condition that precipitated it (i.e., ischemia,
sepsis, toxins). The published literature adds to the confusion
due to the multiple criteria used to diagnose AKI. The
American College of Surgeons Committee on Trauma defines
AKI as a rise in serum creatinine to at least 3.5 mg/dL (0.41.3 mg/dL), whereas National Surgical Quality Improvement
Program® uses a rise of at least 2 mg/dL over baseline.
Multiple other scoring systems are used as well (table 30.1).
Baseline preoperative frailty determination can predict the
outcome of surgical intervention, such as associated
complications, increased length of stay, and destination at
discharge (e.g., care facility), as well as hospital readmission,
30-day mortality, and long-term mortality. Frailty is superior
to both American Society of Anesthesiologists class and age
in predicting in-hospital complications and hospital length of
stay. Many frailty scores are available to attempt to quantify
this state, ranging from lengthy to brief. The Frailty index
includes 50 questions related to patient history. It has gained
popularity, because it does not require a physical
examination, and the answers can be obtained from those who
know the patient well.
Strategies used to reduce the risk have included the judicious
use of intravenous fluids, avoidance of high-volume
crystalloids with supraphysiologic chloride concentrations,
invasive hemodynamic monitoring, and maintenance of renal
perfusion with volume infusion with or without inotropes.
The American College of Surgeons National Surgical Quality
Improvement Program (NSQIP®) Surgical Risk Calculator
was developed in 2013 and revised in 2016, using highly
detailed and accurate data from more than 2.7 million patients
in 600 hospitals to estimate patient-specific postoperative
complication risk for more than 1900 operations. Entering 23
Furosemide is unlikely to improve mortality or renal function
because AKI is increased in patients who are or who become
hypovolemic. Further, furosemide has an added toxic effect
when given with other nephrotoxic drugs (e.g.,
aminoglycosides,
nonsteroidal
anti-inflammatory
54
medications). N-acetyl cystine may have some benefit in
reducing contrast-induced AKI, but studies have not been
consistent. It does have a very low risk of adverse side effects
and is inexpensive. Likewise, sodium bicarbonate has been
proposed to reduce the incidence of contrast-induced renal
injury, because alkalization of urine might mitigate the toxic
effect of the contrast medium. However, routine use in the
intensive care unit is not recommended. In the late 1970s,
low-dose (or renal-dose) dopamine was thought to be renal
protective by augmenting renal blood flow and maintaining
glomerular filtration. Despite overwhelming evidence to the
contrary, renal-dose dopamine is still used inappropriately in
many intensive care units around the world. There is evidence
that the increased delivery of sodium to potentially ischemic
tubules as the result of dopamine infusion might increase
oxygen demand and potentiate oxygen debt.
Multiple studies have examined the optimization of fluid
volume based on goal-directed strategies, which focus on
cardiac output and oxygen delivery. Hypovolemia and
hypervolemia are both associated with an increase in AKI in
the perioperative period. Debate continues as to when goaldirected strategies should be initiated (pre- or
intraoperatively), how long they should continue into the
perioperative period, and which fluid is best for correction of
hypovolemia. Unfortunately, the endpoints for optimization
of hemodynamics do not exist for any of the techniques
currently in vogue. Euvolemia is currently the best strategy,
with careful monitoring of renal function in surgical patients
at high risk for AKI.
System
R
1
F
L
E
RIFLE
(Risk, Injury,
Failure, Loss,
End-Stage Renal
Disease)
↑sCr x1.5
baseline or
↓eGFR >25% or
UO <0.5 mL/Kg/
hour x 6 hours
↑ sCr x 2 baseline
or ↓eGFR 50% or
UO < 0.5 mL/Kg/
hour x 12 hours
↑sCr x 3 baseline or
↓GFR2 75% or sCr ≥
4.0 mg/ dL and UO
<0.3 mL/kg/hour x 24
hours or
anuria x 12 hours
Persistent
ARF x
4 weeks
Persistent
ARF ≥3
months
Stage 1
↑sCr>1.5-2.0
x baseline or
UO
<0.5
mL/kg/hour
x 6 hours
↑sCr ≥ 0.3mg/
dL or 1.5-2.0 x
baseline or
UO <0.5
mL/kg/hour x
6-12 hours
Stage 2
↑sCr 2-2.99 x
baseline or UO
<0.5 mL/kg/hour
x 12 hours
Stage 3
↑sCr ≥3 x baseline or
↑sCr ≥ 4.0 mg/dL
with acute increase of
0.5 mg/dL or UO
<0.5 mL/kg/hour x 6
hours
↑sCr ≥ 3x baseline or
UO <0.3 mL/kg/hour
x ≥ 24 hours or anuria
≥12 hours or need for
RRT or ↓ eGFR <35
mL/ minute/1.73 m2
In patient <18 years
AKIN
(Acute Kidney
Injury
Network)
KDIGO
(Kidney
Disease
Improving
Global
Outcomes)
↑sCr 2-3 x
baseline or UO
<0.5 mL/kg/
hour ≥12 hours
Note. sCr = serum creatinine; eGFR - estimated glomerular filtration rate; UO = urine output; ARF = acute renal failure; RRT
= renal replacement therapy.
Table 30.1. Scoring criteria for acute kidney injury.
55
Problems in Related Specialties
72 hours, drainage is still incomplete, surgical drainage is
warranted.
ITEMS 1-35
For each question, select the best possible response.
Category 4 parapneumonic effusions have pus within them.
They have a high risk of poor outcome. Treatment is similar
to Category 3 parapneumonic effusions.
1. A 34-year-old man with a right lower lobe pneumonia
develops a parapneumonic effusion. What finding would
confer the highest possibility of successful treatment with
tube thoracostomy and antibiotics alone?
A.
B.
C.
D.
E.
For this patient, a free-flowing effusion confined to 25% of
the hemithorax describes a category 2 parapneumonic
effusion, which would be amenable to drainage with a smallbore tube. A thickened parietal pleura and a pH less than 7.20
are criteria for a category 3 parapneumonic effusion, and
purulent material within the pleural space is, by definition, a
category 4 parapneumonic effusion. Although tube
thoracostomy is typically the first-line therapy, it may not be
sufficient. Glucose levels in the pleural effusion are not part
of the criteria for categorizing parapneumonic effusions.
Pleural fluid pH less than 7.20
Thickened parietal pleura
Purulent material in pleural space
Free-flowing effusion confined to 25% of hemithorax
Glucose of pleural fluid of 40 mg/dL
ANSWER:
D
A parapneumonic effusion is a pleural effusion arising in
association with an infectious lung focus (e.g., pneumonia,
lung abscess, infected bronchiectasis). Parapneumonic
effusions develop in approximately 1 million patients
annually in the United States. They can progress into an
empyema when the effusion becomes infected. Three stages
of empyema exist: (1) exudative, (2) fibropurulent, and (3)
organizing. Adequate treatment of empyema includes
antibiotic therapy to eradicate the infection and drainage
procedure.
2. A 64-year-old man with chronic obstructive pulmonary
disease presents with worsening shortness of breath,
particularly when he is supine. His chest x-ray is remarkable
for marked elevation of his left hemidiaphragm. The
diagnosis of unilateral paralysis of the left hemidiaphragm is
most reliably made by
A.
B.
C.
D.
E.
The Health and Science Policy Committee of the American
College of Chest Physicians developed a 4-tier categorization
of parapneumonic effusions based on the pleural space
anatomy, the bacteriology of the fluid, and the fluid
chemistry. This schema stratifies patients with
parapneumonic effusions into risk categories for poor
outcomes and recommends whether drainage is necessary.
CT scan of the chest and abdomen.
fluoroscopy.
M-mode ultrasonography.
MRI.
phrenic nerve stimulation.
ANSWER:
Category 1 parapneumonic effusions are minimal, freeflowing effusions (<10 mm on lateral decubitus film) with
very low risk of a poor outcome. Treatment includes
antibiotics and observation.
E
Elevation of the hemidiaphragm may occur in a variety of
settings. It is important deter mine whether the elevation of
the hemidiaphragm is due to other anatomic factors present
in the patient or to unilateral paralysis of the elevated
hemidiaphragm. Unilateral diaphragmatic paralysis may be
tumor related or may occur after a viral infection, surgery, or
trauma. It may also be idiopathic. Paralysis resulting in
chronic elevation of the of the diaphragm is more commonly
unilateral than bilateral, affects the left side more often than
the right side, and affects men more than women. In the
absence of intrinsic lung disease, patients are often
asymptomatic or have only a mild compromise of their
respiratory mechanics Affected patients typically are
hypoxemic and may have symptomatic orthopnea. Unilateral
diaphragmatic paralysis, however, is rarely fatal.
Category 2 parapneumonic effusions are small to moderate,
free-flowing effusions (>10 mm on lateral decubitus film but
less than half the hemithorax) with negative Gram
stain/culture of the pleural fluid and a pH greater than 7.20.
They have a low risk of poor outcome. They require
antibiotics and pleural fluid sampling with thoracentesis.
Complete drainage of free-following fluid should be
undertaken using a small-bore catheter.
Category 3 parapneumonic effusions are large, free-flowing
effusions involving half or more of the hemithorax on lateral
decubitus film, loculated effusions, effusions with thickened
parietal pleura, effusions with positive bacterial Gram stain/
culture, or effusions with a pH less than 7.20. They have a
moderate risk for poor outcome. Patients should have
antibiotic therapy and drainage of the parapneumonic
effusion via tube thoracostomy. If, after 24 hours, drainage is
incomplete, intrapleural fibrinolytics should be tried. If, after
The finding of an elevated hemidiaphragm on a chest X-ray
or CT scan of the chest and abdomen is nonspecific and does
not confirm the presence of a unilateral hemidiaphragm
paralysis. Fluoroscopy is often cited as the method to confirm
the diagnosis of unilateral hemidiaphragm paralysis.
Diaphragmatic motion is recorded using fluoroscopy while
57
the patient sniffs. Brisk downward movement of the
unaffected hemidiaphragm and paradoxical elevation of the
affected hemidiaphragm is considered evidence of unilateral
hemidiaphragm paralysis. Ultrasonography is also described
as a novel method to detect paralysis of the hemidiaphragm.
Both fluoroscopy and ultrasonography, however, are highly
dependent on patient effort and are subject to operator error.
The utility of real-time MRI for the diagnosis of unilateral
paralysis of the hemidiaphragm remains to be determined.
The most reliable test to quantify the mechanical function of
the diaphragm is the measurement of the negative pressure
generated by contraction of the diaphragm. in response to
stimulation of the phrenic nerve. Electrical stimulation can be
accomplished by using percutaneous needle electrodes in the
neck or by single/ B bilateral magnetic cervical coils.
Magnetic stimulation of the phrenic nerves is painless,
reproducible, and easy to perform. Phrenic nerve stimulation
is the best means to distinguish between the neuropathic
conditions (phrenic nerve injury or compression) and
myopathic conditions that can cause unilateral paralysis of
the hemidiaphragm.
Figure 3.2.
ANSWER:
3. A 23-year-old man with a history of asthma presents with
sudden onset chest and neck pain. He is afebrile, and physical
exam demonstrates crepitus in his neck. His white blood cell
count is 11,500/mm3 (3600-11,200/mm3). A chest CT scan
is performed (figures 3.1 and 3.2). Initial management should
consist of
A.
B.
C.
D.
E.
A
The clinical history and CT scan findings are consistent with
spontaneous pneumomediastinum (figure 3.3). This is a
relatively rare condition, thought to be caused by alveolar
rupture with tracking along the bronchovascular bundle to the
mediastinum. Most patients present with chest pain, shortness
of breath, and sometimes neck pain. Asthma is a common
predisposing comorbidity. Smoking and illicit drug use are
also relatively common. Careful review of the patient's
history for trauma, aerodigestive instrumentation, or
vomiting is important, in which case esophageal rupture
would be a diagnostic consideration. White blood cell count
may be mildly elevated, but fever is not common and would
raise suspicion for visceral rupture. Diagnosis is suggested by
physical exam and chest x-ray, showing pneumomediastinum
or subcutaneous air in the neck, and subsequent chest CT scan
is considered the standard of care for diagnosis. Diffuse
pneumomediastinum is seen without pleural effusions (figure
3.4). If effusions or mediastinal fluid collections are present,
they also raise concern for visceral rupture.
observation.
esophagram.
bronchoscopy.
broad-spectrum antibiotics.
transcervical mediastinal drain placement.
Given this patient's presenting history and clinical condition,
observation without further testing is reasonable. Most
patients need pain control with intravenous pain medication
initially. Esophagram would be indicated when there is a
history of emesis or in the presence of fever, pleural
effusions, or a history of trauma or instrumentation.
Bronchoscopy is not needed without a history of trauma.
Antibiotics are not needed. Drain placement is not necessary
either; the air typically resorbs within a 1 to 3 days.
Figure 3.1.
58
have negative cytology on the first evaluation. Second,
nonexpansile lung after thoracentesis that persists despite
chest tube placement in the absence of air leak defines
"trapped lung," sometimes referred to as "pneumothorax ex
vacuo." It is caused by a combination of tumor implants on
the surface of the lung and chronic compression of the lung
with scar tissue formation. Pneumothorax ex vacuo occurs in
approximately half of all malignant pleural effusions.
A trapped lung is a contraindication to pleurodesis of any
type. The visceral and parietal surfaces are not in contact, and
pleurodesis is doomed to fail. Indwelling pleural catheters are
the only option for palliation in these circumstances. A
second chest tube will not improve the situation with a nonexpansile lung in the absence of air leak and is an unnecessary
step that will make the patient more uncomfortable with no
benefit. Thoracotomy and decortication is overly aggressive
in this 85-year- old man with a large effusion. Surgical
morbidity and mortality are substantial for a problem that is
almost certainly advanced malignancy; there is no therapeutic
benefit to be had.
Figure 3.3. CT scan finding consistent with spontaneous
pneumomediastinum
With expansion of targeted therapy and immunotherapy,
many treatment options have minimal toxicity—obtaining
tissue is critical as long as it is in line with the patient's goals
of care. Thus, a single port video-assisted thoracoscopic
surgery is a reasonable option to obtain pleural biopsies. This
is the standard of care for evaluation of nondiagnostic
cytology with a recurrent pleural effusion.
The second issue is palliation of the large effusion and
dyspnea. The patient's symptoms improved with
thoracentesis even though the lung was trapped, which is
common. Placing an indwelling pleural catheter that can be
drained at home every 1 to 7 days effectively palliates
dyspnea and improves quality of life, with less time in the
hospital.
Figure 3.4. Diffuse pneumomediastinum is seen without pleural
effusions
4. An 85-year-old old man presents with dyspnea and a chest
x-ray with white out of the right chest. CT scan shows
collapse of the right lung with large nonloculated right pleural
effusion. Thoracentesis returns 1 L of serous fluid with
improvement in his dyspnea. After thoracentesis, chest x-ray
shows a pneumothorax. A chest tube is placed, which does
not re-expand the lung. There is no air leak. Cytology
indicates atypical cells. Malignant effusion is suspected.
What is the next step in the management of this patient?
5. A patient is involved in a high-speed motor vehicle
collision. He was restrained, and his airbag deployed. His
primary survey is normal, and his secondary survey reveals
no external injuries. He has complete imaging, and his only
positive finding is a pneumomediastinum on CT scan of the
chest. Which of the following statements is true regarding this
finding?
A. Video-assisted thoracoscopic surgery (VATS) pleural
biopsies with talc sclerotherapy
B. A second chest tube and increased suction
C. Right thoracotomy with decortication of the lung
D. Pigtail catheter with doxycycline pleurodesis
E. VATS pleural biopsies with tunneled pleural catheter
ANSWER:
A. Intubation for occult airway injury is necessary.
B. Observation is appropriate treatment.
C. Workup requires bronchoscopy and esophagogastroduodenoscopy.
D. Mediastinal organ injury will be found in 12% of
asymptomatic patients.
E. Broad-spectrum antibiotics are required.
E
The case describe is a relatively common scenario in the
management of malignant pleural effusions. First, pleural
fluid cytology is not very sensitive, and clinical suspicion and
clinical course should prompt further evaluation for
malignancy. Atypical cells on cytology do not rule out
malignancy, and at least 50% of the time, malignant effusions
ANSWER:
59
B
Pneumomediastinum can be spontaneous or related to
trauma, instrumentation, severe coughing or vomiting, forced
straining, or asthma. The most common presenting symptom
is chest pain or discomfort, followed by dyspnea and neck
pain. It is most often identified on CT imaging. In
spontaneous pneumomediastinum, associated injury to the
esophagus, trachea, or mediastinal structures is uncommon,
and extensive workup, including swallow studies,
bronchoscopy, or upper endoscopy, are not required. In
patients who (1) have had recent instrumentation (e.g.,
bronchoscopy or upper endoscopy), (2) have sustained
penetrating trauma, (3) had violent retching, or (4) have
associated pleural effusion, the chance for mediastinal organ
injury is higher and workup should be considered. Broadspectrum antibiotics are not indicated unless specific
mediastinal contamination is present. Asymptomatic blunt
trauma patients can be safely observed because mediastinal
injury occurs in less than 2%.
Figure 6.2.
ANSWER:
Based on the history of retching and the imaging studies
showing mediastinal air and gross soilage of the pleura and
mediastinum, this patient almost certainly has suffered a
spontaneous distal esophageal perforation secondary to
emetic barotrauma, also known as Boerhaave syndrome
(figures 6.3 and 6.4). Furthermore, this patient's condition has
progressed to sepsis, most likely due to mediastinitis. As with
all cases of septic shock, therapeutic intervention is urgent
and usually begins with fluid resuscitation and broadspectrum intravenous antibiotics. In patients with Boerhaave
syndrome presenting with gross mediastinal and pleural
contamination, surgical intervention is the mainstay of
therapy.
6. A 19-year-old college student with food poisoning has
been vomiting and retching for 12 hours. He complains of
chest pain, high fevers, and shortness of breath. A CT scan of
the chest was obtained (figures 6.1 and 6.2). His vitals are as
follows: Temp 38.9°C, heart rate = 120 beats per minute,
blood pressure - 110/70 mm Hg, and white blood cell count 25,000/mm3 (3600-11,200/mm3). After administration of 2
L of normal saline and broad-spectrum antibiotics, what is the
optimal next step in management?
A.
B.
C.
D.
E.
B
Endoscopic placement of a covered esophageal stent
Surgical repair of the esophageal tear
Esophagectomy with cervical esophagostomy
Endoscopic mucosal clipping
Chest tube placement and 48 hours of antibiotics
Thoracotomy with primary esophageal repair is the standard
of care in Boerhaave syndrome. The approach is commonly
via left thoracotomy with possible phreno-laparotomy to
widely expose the site of the tear, usually at the
gastroesophageal junction. Copious irrigation of the
mediastinum and pleural space plus debridement of all
devitalized tissue is important. Once the devitalized tissue is
cleared away, primary full-thickness esophageal repair is
performed if possible. Reinforcement of the repair may be
accomplished with a fundic wrap or pleural flap. The
mediastinum and pleura are widely drained with large bore
chest tubes.
Esophagectomy with cervical esophagostomy would be
recommended only in those patients presenting with
widespread esophageal necrosis, in whom esophageal repair
would be impossible. These patients usually present for
treatment more than 24 hours after the inciting event.
Figure 6.1.
Some patients presenting early in the course of the condition
with contained rupture and stable hemodynamics may benefit
from nonoperative management. Nonoperative management
should be considered only for patients with small ruptures
contained in the mediastinum draining back into the
esophagus, absence of pleural contamination, and no
evidence of sepsis. If nonoperative management is attempted,
60
8. A spontaneous pneumothorax in a 66-year-old man with
metastatic lung cancer and pleural effusion
9. A second episode of spontaneous pneumothorax in a 26year-old
ANSWERS:
A, C, B
Spontaneous pneumothorax should be managed promptly to
avoid the complications of tension pneumothorax. The
specific treatment is based on the patient's underlying
condition. For an otherwise healthy 18-year-old patient, a
small anterior chest tube directed apically is definitive
treatment in more than 70% of patients presenting with a
spontaneous pneumothorax. A low thoracostomy tube placed
to allow drainage of an effusion is not necessary. For patients
with high-risk activities such as flying in airplanes or scuba
diving where another episode could be a fatal event,
moredefinitive procedures such as pleurectomy, bleb
resection, and pleurodesis are recommended. For patients
who experience a second episode of spontaneous
pneumothorax, a definitive procedure is also clearly
indicated.
Figure 6.3. Esophageal rupture with air leakage into the
mediastinum (white arrow) and left-sided pleural effusion.
For a patient with metastatic cancer, the issue becomes how
to manage the pneumothorax and maximize his or her quality
of life. A simple anterior tube will address the pneumothorax
but will not be adequate to drain the effusion. A low tube
thoracostomy may never be removed due to persistent
exudate and may have a negative impact on a patient's quality
of life. Thoracoscopy with lung resection may eliminate the
source of the air leak (if it is technically possible) but is
accompanied by much greater risk in this patient.
Figure 6.4. Complications of the esophageal rupture.
Mediastinitis (induration of the mediastinal fat) and extensive leftsided pleural effusion with air pockets.
nothing by mouth, antibiotics, and chest tube drainage of
pleural/ mediastinal fluid are necessary. Some of these
patients may benefit from placement of covered esophageal
stent, and some centers prefer stent placement as first-line
treatment in these patients. Other centers describe the use of
endoscopic clips to dose the mucosal defect associated with
acute esophageal perforation. Although successful treatment
of Boerhaave syndrome using endoscopic clips is possible,
this method would apply only to patients early in the course
of the condition and only in centers with considerable
experience in advanced therapeutic endoscopy.
Elimination of the potential pleural space to allow a prompt
discharge from the hospital should be the goal of therapy.
Assuming the lung can be re-expanded, drainage of the chest
with pleurodesis to obliterate the space can be performed at
the bedside or in the operating room with sedation and pain
control. Concerns do exist with the use of talc as a potential
carcinogen. Animal studies have documented talc migration
to sites remote from the area of application. This is not an
issue, however, in this patient with metastatic disease. If the
lung cannot be re-expanded, a tunneled catheter maybe
appropriate because the effusion will likely recur.
Items 7-9
Each lettered response may be selected once, more than once,
or not at all.
A.
B.
C.
D.
10. A 32-year-oId woman presents to the emergency
department with left-sided pelvic pain. Pregnancy test is
negative. Transvaginal ultrasound reveals a 3-cm tuboovarian abscess. After 2 days of intravenous antibiotics, she
continues to have severe pain and fever. Repeat imaging
shows the abscess has grown to 7-cm. What is the best next
step in her care?
7. A spontaneous pneumothorax in an 18-year-old healthy
male runner
A. Addition of antifungal therapy
B. Transvaginal drainage
C. Laparoscopic drainage
Anterior placement of a small pleural drainage catheter
Apical pleurectomy and pleurodesis
Pleurodesis with talc installation
Thoracostomy tube placement mid axillary line, 8th
intercostal space
E. Thoracoscopy with lung resection
61
D. Left salpingo-oophorectomy
E. Total abdominal hysterectomy with bilateral salpingooophorectomy
ANSWER:
ANSWER:
D
Endometriosis is a painful condition of the lining of the
uterus. It affects women of reproductive age. The
endometrium starts growing outside the uterus, manifesting
as superficial peritoneal implants or cyst formation
commonly referred to as an endometrioma. These cysts or
endometriomas are formed when ectopic endometrial tissue
within the ovary bleeds and results in a hematoma. They
typically have fibrotic walls and surface adhesions, are filled
with a thick chocolate-colored fluid, and are surrounded by
ovarian tissue.
C
Tubo-ovarian abscesses can form as a result of pelvic
inflammatory disease and are present in up to one-third of
patients hospitalized for pelvic inflammatory disease. These
abscesses form when an ascending infection travels up the
fallopian tube, and they can vary significantly in size and
severity. Most patients present with abdominopelvic pain and
fever, but some patients also experience vaginal drainage.
Physical exam will reveal lower abdominal pain and
occasionally a pelvic mass. Pelvic exam may demonstrate
cervical motion tenderness. Although transvaginal ultrasound
is considered first-line imaging, most patients will undergo
CT scanning to further clarify the size and location of the
abscess.
There is debate regarding surgery for asymptomatic
endometriomas. Ovarian-sparing excision for large
endometriomas is appropriate. This results in improved pain
control and less recurrence compared with ablation, drainage,
or observation. Oral contraceptives may reduce recurrence,
but they are not effective in treating an endometrioma once it
is established.
The initial treatment of smaller (<4-5 cm) tubo-ovarian
abscesses is intravenous antibiotics, which is successful in up
to 70% of patients. Large abscesses (>7-8 cm) or patients with
persistent or progressive symptoms require abscess drainage
to ensure sepsis resolution. Offending pathogens are typically
bacteria such as Chlamydia trachomatis and Neisseria
gonorrhoeae; antifungal agents will rarely assist in abscess
resolution.
12.
A 71-year-old man has a 46-year history of
nephrolithiasis, but no additional significant medical history.
He has undergone 2 ureteral basket extractions of stones and
8 episodes in which the stones spontaneously passed. The
patient recently complained of persistent left costovertebral
angle and flank pain prompting CT scan, which shows large
left renal calculus (figure 12.1). Workup on 2 occasions in the
past demonstrated normal serum calcium and intact
parathyroid hormone levels. After a successful percutaneous
nephrolithotomy, stone analysis demonstrated the stones to
be calcium oxalate-monohydrate and the following additional
findings:
sCa++ = 9.3,9.0, 9.1
(8.4-10.3 mg/dL)
uVolume = 2.67
(>2.0 L/day)
uCaOx = 3.25
(6-10)
uCa++ = 162
(<250 mg/day)
uOx = 31
(20-40 mg/day)
uCitrate = 184
(>450 mg/day)
upH = 5.489
(5.8-6.2)
uUric acid = >0.800
(>0.800 g/day)
s = serum; u = 24-hour urine
The approach to abscess drainage has evolved over time.
Original recommendations included total abdominal
hysterectomy with bilateral salpingo-oophorectomy; later
recommendations focused on unilateral salpingooophorectomy. Such procedures are no longer used due to
associated morbidity and infertility. Instead, simple abscess
drainage can be done with excellent success rates. This is
typically accomplished via laparoscopic drainage, with care
taken to avoid spillage of the purulent material into the
abdomen. Alternatively, percutaneous abscess drainage can
be performed.
Tubo-ovarian abscesses secondary to pelvic inflammatory
disease typically occur in younger patients. The finding of
tubo-ovarian abscesses in postmenopausal women should
raise concern for gynecologic malignancy, which is present
in almost half of older patients.
Management at this point should include
11. A 32-year-old woman with a medical history of a
ruptured appendix undergoes an exploratory laparotomy for
small bowel obstruction. A 6-cm endometrioma of the right
ovary is discovered. What is the best treatment?
A.
B.
C.
D.
E.
A.
B.
C.
D.
E.
Oral contraceptives
Drainage
Oophorectomy
Ovarian-sparing excision
Observation
62
(Tc)-99m sestamibi scintigraphy.
repeat serum parathyroid hormone level.
potassium citrate.
bisphosphonate.
furosemide.
A diagnosis of primary hyperparathyroidism is always a
consideration in patient who are recurrent CaSF. The normal
serum calcium levels and the history of normal intact serum
parathyroid hormone (iPTH) levels excludes the diagnosis of
primary hyperparathyroidism in this case. Further, the normal
iPTH and the normal 24-hour uCa++ excretion make the
diagnosis of normocalcemic hyperparathyroidism unlikely.
As such, repeating a serum iPTH level or localizing an
abnormal parathyroid gland by nuclear scanning is irrelevant.
Thiazide diuretics are used, with or without alpha-blockers
such as tamsulosin (which increases urinary pH and promotes
passage of small stones and crystals from the collecting
system and ureter) in patients with hypercalciuria, but
furosemide is not appropriate. Bisphosphates, along with
exercise, are used to prevent bone loss and renal stone
formation in astronauts and patients subject to prolonged bed
rest, but evidence for effectiveness of this strategy is largely
theoretical and limited to small observational clinical data.
Potassium citrate and potassium-magnesium citrate reduce
the frequency of recurrent calcium-stone formation,
particularly calcium oxalate stones. Citrate is thought to be an
inhibitor of calcium oxalate crystal formation. This treatment
would be appropriate in this patient with calcium oxalate
stones and low levels of urinary citrate. Increasing the
consumption of high citrate-containing fluids such as fruitB
juices and lemonade is proposed as a potential strategy to
reduce stone formation. Whether the beneficial effect is
achieved through reducing calcium-oxalate crystal formation
or by increasing urinary volume is debated.
Figure 12.1. Large left renal calculus.
ANSWER:
C
Despite decades of research and clinical experience, multiple
issues regarding the physiochemical mechanisms of stone
formation and treatment of the calculi in recurrent stone
formers remain contested. Stone disease appears to be
increasing in the United States, from 1:20 individuals to 1:11
over the past 20 years and is being associated with the
increasing prevalence of obesity and metabolic syndrome.
This is true across all ethnic groups and ages.
13. A 75-year-old, 82 kg, man is found on CT scan to have
an enhancing left renal mass that measures 2.5 cm.
Comorbidities include diabetes mellitus and compensated
congestive heart failure. His serum creatinine is 1.6 mg/dL
(0.40-13 mg/dL), and his estimated creatinine clearance is 46
mL/minute (97-137 mL/ minute). What is the most
appropriate management approach?
Historically, men have been the prevalent stone formers, but
recent epidemiologic data indicate that the gap between men
and women is closing (10.6% men vs 7.1% women), as more
women are being identified as calcium-stone-formers
(CaSF).
A.
B.
C.
D.
E.
Most researchers agree that the initial process of stone
formation begins with supersaturation of urine with solutes
capable of crystal formation. Whether crystals that do form
produce stones by crystal growth or crystal aggregation, the
role of modulators (promoters and inhibitors of crystal
formation) and the role of renal tubular epithelial injury
(Randall plaques or plugs, lesions on which crystals may
adhere) remains debated. Efforts to reduce supersaturation of
urine by increasing fluid intake to a goal of 24-hour urine
production of more than 2 L is the first step in efforts to
prevent recurrent stone formation.
Cryoablation
Active surveillance
Radical nephrectomy
Laparoscopic enucleation of the lesion
Partial nephrectomy with hilar lymph node dissection
ANSWER:
B
Current literature reports an increase in the incidence of renal
cell carcinoma (RCC), largely due to the increased
availability and frequency of imaging studies used in patient
management. The identification of incidental renal lesions in
asymptomatic patients has confounded the decisions about
how to proceed with workup and treatment. The greatest
increase in the detection of RCC is in elderly patients, many
of whom have comorbidities that complicate the
decisionmaking process. As such, clinicians must determine
63
the balance between life expectancy related to the associated
comorbidities and the anticipated cancer-related outcomes.
2.0 times normal reconsider their management options. Zerogrowth rate does not imply a benign nature of the lesion, but
studies from Fox Chase Cancer Center and Vanderbilt
University showed that there is no adverse impact on outcome
that results from a delay in intervention of 6 to 12 months.
The appropriate interval for repeat imaging is not clearly
defined.
The goals of treatment include not only cancer-free survival
but also preservation of renal function and quality of life.
Radical nephrectomy, the standard of care for the
management of malignant renal tumors, is associated with a
5-year survival of more than 95%, and approaching 100% in
some reports, yet it comes with the cost of loss of renal
function. This is acceptable in younger patients, but it
increases the risk of cardiovascular events in the older patient
population. Nephron-sparing surgery, including partial
nephrectomy (open or laparoscopic) and ablative techniques
(cryoablation and radiofrequency ablation), has equivalent
short- and intermediate-term oncologic outcomes while
minimizing the loss of renal function. For most early-stage
RCCs, the routine addition of nodal excision, with both
radical nephrectomy and nephron-sparing surgery, offers
little in terms of survival benefit and is currently reserved for
patients who have suspicious lymphadenopathy identified by
preoperative imaging.
14. A 45-year-old man notes one episode of blood in his
urine. He has no pain, urinary incontinence, urgency, or
dysuria. He has no medical or surgical history and takes no
medications. His vital signs are normal, and a physical
examination is normal. His basic metabolic panel is normal.
The only abnormality on urinalysis is 10 red blood cells per
high powered field. The first step in his management should
be
A.
B.
C.
D.
E.
Several methods exist to determine survival based on
comorbidities. The most thoroughly studied and extensively
validated is the Charlson Comorbidity Index (CCI). For each
unit increase in the CCI, the hazard ratio for death increases
by 1.33 and increases by 1.35 for each 5 years of additional
age. In the patient presented, the expected 1-year and 2-year
survival is approximately 64% and 35%, respectively. When
this is considered in the context that 40% of incidentally
identified small renal masses (Tla, <4 cm) are benign and that
another 40% will follow an indolent course, the data suggest
that observation alone may be the prudent course.
urine cytology.
repeated microscopic analysis in 6 months.
cystoscopy.
abdominal CT scan.
antibiotics.
ANSWER:
C
Asymptomatic microhematuria (ASH) is defined as 3 or more
red blood cells per high powered field in the absence of
apparent benign causes such as trauma, infection, vigorous
exercise, and viral illness. The workup focuses on detection
of urologic malignancy in the upper and lower urinary tract,
which occurs in 2.6 to 4% of patients with ASH. American
Urological Association updated guidelines recommend a
workup in patients age 35 years and older. Although intrinsic
renal disease can cause hematuria, abnormal renal function or
other microscopic abnormal findings in the urinalysis will
typically point toward this, and a workup for neoplasm is still
indicated in these patients. Multiphasic CT urogram with and
without intravenous contrast to evaluate the renal
parenchyma and upper urinary tracts is sensitive and specific
(>90%) for neoplasms, with only a small risk of contrastrelated adverse events.
Clinical studies exist to support this approach. A Cleveland
Clinic study of patients with enhancing renal lesions in an
elderly cohort noted a 33% mortality at 2 years, but no
mortality was related to RCC. In another study of more than
537 patients at least 75 years old, cardiovascular mortality
exceeded mortality from renal malignancy and was not
related to the treatment strategy used. Data from the
prospective, multi-institutional Delayed Intervention and
Surveillance for Small Renal Masses (DISSRM) study
indicated that the 2-year survival for patients in an active
surveillance arm versus a treatment arm was 96% and 98%,
respectively, with a 5-year survival of 75% and 92%. Cancerspecific survival was 100% for the treatment cohort and 99%
for the surveillance group. These results led the authors of this
and other studies to conclude that for small renal tumors (1)
active treatment is not associated with increased survival, and
(2) overtreatment of these lesions is possible.
Ninety percent of bladder cancers present with hematuria,
Cystoscopy is also recommended for all patients 35 years and
older to evaluate for bladder neoplasm. Urine cytology is not
sensitive enough, particularly for low-grade urothelial cancer,
to be used in the routine workup of ASH, and negative results
should not preclude a full workup. Repeat evaluation in 6
months is inadequate because substantial prior research is
based on a single test result and has shown that repeated
urinalyses are not necessary to improve the yield on a
workup. A standard abdominal CT scan is not sufficient to
detect renal neoplasms and would not be adequate.
Antibiotics to treat an occult infection that may contribute to
hematuria would overlook the possibility of neoplasm and are
not recommended in the absence of a urinary tract infection.
Active surveillance, defined as interval imaging without
active treatment, is appropriate for patients with advanced age
or significant comorbidities that impose greater risks for
operative mortality and complications. The mean growth rate
for small renal masses is 0.28 cm/year, and as many as onethird of them have a zero-growth rate. Some authors suggest
that patients whose lesions show elevated growth rates 1.5 to
64
B.
C.
D.
E.
15. Which of the following statements is true regarding
iatrogenic ureteral injury during abdominal operations?
A. It occurs in 3% of radical excisions for uterine cancer.
B. It is prevented by preprocedure stent placement.
C. Thermal injury to the distal third of the ureter is best
repaired primarily.
D. Transection of the middle third of the ureter may be
repaired with a Boari flap.
E. Psoas hitch is indicated for ureteropelvic junction
injuries.
ANSWER:
gastrointestinal hemorrhage.
pneumoperitoneum.
peritonitis.
ileus.
ANSWER:
A
Neutropenic enterocolitis— also known as typhlitis, ileocecal
syndrome, cectis, or necrotizing enterocolitis— is a severe
condition that affects immunocompromised patients.
Neutropenic enterocolitis was initially described in leukemic
pediatric patients and is also reported in adults with
hematological malignancies. The exact pathogenesis remains
unknown, but the hallmarks of the disease include intestinal
mucosal injury with neutropenia.
D
Ureteral injuries are a complication of extensive dissections
in cases of advanced cancer, previous pelvic dissections,
radiation, and infection. The incidence varies on the
experience of the operator and the extent of disease. In cases
of low pelvic surgery where the ureter is near the operative
field, the reported incidence of injury
ranges
from
0.18 to 0.29% for gynecologic and 0.18 to 7.8% for colorectal
procedures.
The clinical presentation includes fever, abdominal pain,
neutropenia, and thickening of the bowel wall (most
commonly the cecum and ascending colon). The thickness of
the bowel wall correlates with mortality. Studies show a
higher mortality rate in patients with ultrasound-measured
colonic wall thickness of at least 10 mm compared with those
with a thickness less than 10 mm. Other clinical findings of
neutropenic enterocolitis include hypotension and diarrhea.
The duration of neutropenia, lack of surgical intervention,
and presence of severe sepsis are associated with a poorer
overall
survival.
Gastrointestinal
hemorrhage,
pneumoperitoneum, peritonitis, and ileus, while associated
with neutropenic enterocolitis, are not absolute diagnostic
criteria.
Preprocedural ureteral stent placement should facilitate
identification of the ureter in difficult cases. Risks associated
with stent placement include infection, oliguria,
hydronephrosis, and hematuria. Previously published series
have not found a decreased incidence of injury. Surgeons
hypothesized that the stent actually makes the ureter less
pliable and more prone to injury during dissection. The
undisputed advantage of the stent is the ability to recognize
the injury promptly.
Items 17-19
Each lettered response may be selected once, more than once,
or not at all.
If the injury to the ureter is not from electrocautery and is very
small, primary repair over a stent can be performed. For
thermal injuries or large segment transactions, the edges
should be debrided to viable tissue before contemplating
repair. Injuries in the distal third of the ureter may often be
able to be reimplanted to the bladder, provided there is no
tension. Bladder mobilization and attachment to the psoas
muscle (psoas hitch) can facilitate this. When the bladder
cannot be mobilized, creating a tube from the bladder (Boari
flap) can be used to anastomose the bladder directly to the
ureter. More proximal injuries are managed with temporary
external drainage or renal autotransplantation to a position
lower in the pelvis. Expertise from urologic or transplant
surgeons is often necessary.
•
•
•
•
•
Pain in right lower quadrant caused by palpating the left
lower quadrant
Pain on extension of the thigh
Pain on flexion of the thigh
Pain on flexion and internal rotation of the hip
Pain on flexion and external rotation of the hip
17. Obturator sign
18. Psoas sign
19. Rovsing sign
ANSWER:
16. A 7-year-old girl is receiving active treatment for acute
leukemia and presents with abdominal pain. In addition to
abdominal pain and neutropenia, the diagnostic criteria for
neutropenic enterocolitis includes
D, C, A
For decades, the diagnosis of acute appendicitis was based on
history and findings on physical examination. The typical
history is anorexia, followed by epigastric or periumbilical
pain that migrates to the right lower quadrant, peaking at
approximately 4 hours. Physical examination findings are
considered to be dictated by the physical location of the
A. bowel wall thickening on imaging.
65
appendiceal tip and the degree of inflammation (table 1719.1).
Rovsing sign
Palpation of left lower quadrant resulting in pain
in the right lower quadrant
Psoas sign
Patient positioned on left side and the right thigh
is extended, stretching the iliopsoas muscle,
eliciting pain if the tip of an inflamed retrocecal
appendix is closely approximated
Obturator sign
Patient positioned supine, passively internally
rotate the flexed right thigh, pain is elicited from
an inflamed pelvic appendiceal tip near the
obturator muscle
testis cannot be manipulated into the scrotum without causing
pain due to traction on the spermatic cord.
A small proportion of retractile testes become pathologic.
Indications for surgery include development of pain in the
cord when manipulating the testis into the scrotum, a testis
that will no longer stay in the scrotum and immediately
springs back into the groin, and a decrease in testicular
volume. Whenever these conditions are recognized, an
orchiopexy should be performed. In one longitudinal study,
approximately 16.3% of boys diagnosed with retractile testes
required surgery during long-term follow-up. The mean age
at diagnosis was 3.0±2.7 years and mean age at normal
descent was 4.3±3.3 years. Of 64 retractile testes, 26 cases
(40.6%) remained retractile until the end of adolescence.
Close observation is required until the testis has descended
into the scrotum or until the end of adolescence.
Table 17-19.1. Classic signs of acute appendicitis on physical
examination.
These findings include right lower quadrant tenderness and
frequently point tenderness at the McBurney point.
Associated findings are localized peritonitis with guarding
and rebound tenderness. Other classic signs on physical
examination include Rovsing sign, psoas sign, and obturator
sign. Flexion of the thigh or flexion and external rotation does
not put the appendiceal tip in proximity to a muscle group.
21. What is the ideal way to determine whether the condition
pictured (figure 21.1) is caused by an incarcerated hernia or
infection?
A.
B.
C.
D.
E.
20. Retractile testes
A.
B.
C.
D.
E.
Ultrasound
Aspiration
Rectal examination
Abdominal x-ray, including the scrotum
Operative approach through the groin
are a variant of the undescended testis.
are normal only in infants.
require operation by the age of 5 years.
must be in the scrotum some of the time.
are normal at any age.
ANSWER:
D
A retractile testis is a variant of the normal testis. An active
cremaster reflex is not uncommon in infants and young boys
and may pull the testis out of the scrotum under normal
circumstances, including when the child is cold or scared.
This can be normal until puberty, when increased androgen
secretion results in relaxation of the cremaster reflex, and the
testis should be in the scrotum virtually all of the time. The 3
requirements of a retractile testis are as follows: (1) the testis
can be palpated in the groin and manipulated into the
scrotum; (2) after manipulation into the scrotum, the testis
remains in the scrotum at least transiently, without being held
there, until the cremaster reflex is stimulated again; and (3)
the parent or guardian must notice that the testis is in the
scrotum at least part of the time.
Figure 21.1.
ANSWER:
A
Groin pathology is common in infants and children. The
differential diagnosis includes uncomplicated and
complicated inguinal hernias and complicated and
uncomplicated inguinal adenopathy. Medical and surgical
treatments differ for each condition. The patient in the
photograph may have either an incarcerated and possibly
strangulated hernia or an inguinal abscess. Physical findings
and diagnostic aids can assist in making the correct
preoperative diagnosis. For example, a child who is eating
A retractile testis is clinically distinguishable from an
undescended testis. In congenital undescended testis, the
testis has never been present in the scrotum. An undescended
66
and drinking and stooling normally and looks well is unlikely
to have an incarcerated hernia. A rectal exam with one hand
on the groin may allow palpation of something caught in the
inguinal canal and groin adenopathy or an abscess will be
lateral to this.
22. Which of the following has consensus with respect to
diagnosis and treatments biliary dyskinesia in adolescents?
A.
B.
C.
D.
E.
Aspiration is relatively contraindicated unless there is
diagnostic certainty of an abscess, because there might be a
loop of bowel in the inguinal canal. An abdominal x-ray will
show whether there are bowel loops below the inguinal
ligament, but there could also be omentum stuck in a hernia
sac and the bowel configuration may be normal despite the
presence of a hernia. An ultrasound is the best diagnostic tool
to examine the groin, because an abscess will have certain
characteristics and be lateral to the inguinal canal. An
ultrasound will also show tissue within the inguinal canal
(figure 21.2).
Symptoms
Diagnostic criteria
Gallbladder ejection fraction
Indications for surgery
Lack of durable symptom relief after cholecystectomy
ANSWER:
E
Surgical treatment of children with a diagnosis of biliary
dyskinesia is controversial and generally directed by
symptoms as well as the results of a cholecystokininstimulated hepatobiliary scan. In a systematic review of 31
published articles, diagnostic criteria, indications for surgery,
and gallbladder ejection fraction values varied. An abnormal
gallbladder ejection fraction is defined institutionally and is
generally less than 35%. However, there is no standard,
validated method for assessing gallbladder motility in
children.
Some centers used a gallbladder ejection fraction up to 50%
as abnormal, and 2 centers only looked at patients with
hyperkinesia (gallbladder ejection fraction >70 or 80%).
Diagnostic criteria were variable and included abdominal
pain (e.g., "classic" biliary colic, right upper quadrant,
epigastric), nausea and vomiting, fatty food intolerance,
anorexia, weight loss, and a normal gallbladder ultrasound.
There was no consensus on the indications for
cholecystectomy. Some studies randomized patients to
medical management or surgery, with nonoperative
management generally including add blockers, again with
variable success. Some investigators reported better success
without surgery, and some reported better success with
surgery.
Figure 21.2. Groin ultrasound demonstrating bowel in the hernia
sac and normal testes.
If all else fails and there is still diagnostic uncertainty, the
surgeon can approach this case as if it were a complicated
hernia with a groin incision above the pathology (figure 21.3).
If no hernia is found, this incision can be closed and the
abscess drained through a counterincision directly over the
area of maximal fluctuance in the groin.
Outcomes were reported in several studies after laparoscopic
cholecystectomy. Four studies correlated poorer outcomes
with a longer duration of symptoms. A lower gallbladder
ejection fraction (<11% or <15% in separate studies)
independently predicted success. Immediate relief of
symptoms was more common than durable symptom relief,
with many patients relapsing within several weeks of
operation. Resolution was defined as complete cessation of
symptoms without recurrence and ranged from 34 to 100%.
Thirteen studies reported resolution of symptoms in 54 to
100% of patients for 2 weeks to 6 months after surgery.
Duration of symptom resolution after surgery ranged from 6
days to 11 years, and only 66% of patients remained symptom
free at long-term follow-up.
Figure 21.3. Groin incision used to exclude hernia. Groin abscess
drained after initial incision closed.
67
23. The major difference between a patient-centered
outcomes trial and a randomized controlled trial is
A.
B.
C.
D.
E.
4 pediatric appendectomies annually appear to have similar
outcomes to their pediatric surgical colleagues. Patients of
general surgeons and pediatric surgeons have similar lengths
of stay, readmission rates, and complication rates like wound
infection as well as mortality for both complicated and
uncomplicated acute appendicitis. The only statistical
difference consistently identified is lower rates of negative
appendectomy when the operation is done by pediatric
surgeons compared with general surgeons.
choice of care.
reduced cultural bias.
decreased investigator bias.
reduced enrollment of patients.
no need for informed consent.
ANSWER:
A
In a controlled randomized trial, patient and family receive
oral and written information regarding the trial and consent
to the trial but are randomized to the treatment. In a patientcentered (patient and family choice) trial, patients and family
receive oral and written information regarding the trial and
consent to the trial, but they choose the treatment they prefer.
25. An 11-year-old girl with Crohn terminal ileitis is being
treated with azathioprine and steroids, but she continues to
have episodes of abdominal pain and partial bowel
obstruction. Her mother is concerned that she is losing weight
and becoming socially withdrawn. What is the most
appropriate next step in management?
The patient and family choice design produce potential
selection bias by the investigator. Bias can be minimized by
using a standardized scripted consent process and welldefined inclusion and exclusion criteria. Patient and family
choice design also may lead to unbalanced patient
characteristics that may result in differences in treatment. For
example, in a published patient and family choice trial done
in a single institution comparing nonoperative to operative
management of pediatric uncomplicated acute appendicitis,
parents or guardians whose primary language was not English
were more likely to select nonoperative management.
However, those choosing nonoperative management as a
personal choice were less likely to worry about recurrent
appendicitis than those who were randomized to nonoperative
treatment. The ability to choose the preferred treatment
generally enhances enrollment in a clinical trial.
A.
B.
C.
D.
E.
ANSWER:
For children with moderate to severe Crohn disease, initiation
of biologic therapy with either infliximab or adalimumab has
a significant clinical benefit in 88% of patients; 50 to 60% of
these patients will achieve clinical remission, with a similar
number able to wean off oral steroids. Infliximab has the
greatest success in this arena, with adalimumab typically
reserved for second-line treatment.
shorter lengths of stay.
lower surgical site infection rates.
lower negative appendectomy rates.
higher readmission rates.
lower pelvic abscess rates.
ANSWER:
C
For children with inflammatory bowel disease, an important
indicator of inadequate treatment is failure to thrive, which
can include weight loss, growth delay, social withdrawal, and
inactivity. The patient described is worsening despite an
immunomodulator and ongoing steroids. Escalation of
therapy is warranted.
24. Comparing the outcomes of general and pediatric
surgeons, children with appendicitis managed by pediatric
surgeons have
A.
B.
C.
D.
E.
Addition of aminosalicylates
Switch from azathioprine to 6-mercaptopurine
Infliximab infusion
Ileocolectomy
Diverting loop ileostomy
Aminosalicylates have limited efficacy in Crohn disease for
both children and adults and are not useful for severe disease.
Although the child may need to remain on an
immunomodulator, conversion from one to another (e.g., 6mercaptopurine) is not an adequate escalation of therapy.
Ileocolectomy is warranted for failure of medical therapy and
should be performed if biologies are ineffective. A diverting
loop ileostomy may partially alleviate symptoms, but it does
not remove the diseased bowel segment. This surgery may
worsen the child's body image, so it should be reserved for
the rare situation in which resection is not feasible.
C
Appendectomy is the most common urgent surgical
procedure performed in the pediatric patient population. In
the current era of subspecialization and regionalization,
questions remain as to what surgical procedures general
surgeons should be performing versus sending patients on to
specialty surgeons or centers. The most important factor
appears to be surgeon volume, not presence or absence of
subspecialty training. General surgeons who perform at least
26. An otherwise healthy 2-year-old boy is referred for an
asymptomatic umbilical hernia found on routine exam.
68
Examination reveals a reducible hernia with a 1-cm fascial
defect. What is the most appropriate treatment?
A.
B.
C.
D.
E.
Observation
Abdominal binder
Primary repair
Repair with polypropylene mesh
Repair with bioabsorbable mesh
ANSWER:
A
Small, asymptomatic umbilical hernias are very common in
young children. They are present in 10 to 20% of all infants,
and up to 75% of those bom prematurely with weights less
than 1500 g. Complications of these hernias are rare, and
incarceration or strangulation occurs in less than 1% of
patients.
Figure 27.1.
Many small hernias will close spontaneously, including 80%
of hernias smaller than 1 cm and 96% of hernias smaller than
0.5 cm. For this reason, the most appropriate management of
small asymptomatic hernias in the first 4 years of life is
observation. Abdominal binders have no proven benefit for
symptom control, defect closure, or prevention of
complications.
ANSWER:
C
Management of ingested and aspirated foreign bodies is a
common task for surgeons caring for children, but button
batteries are a special emergency. The severity of the injury
of button batteries has increased for 2 reasons: (1) larger sizes
can become lodged in the airway and esophagus and (2) more
powerful lithium cells are being ingested (1-25% of
ingestions). Button batteries produce hydroxyl radicals in the
mucosa, causing a caustic injury from high pH, not from
electrical, thermal, or pressure effects.
27. A 4-year-old boy presents to the emergency department
with a suspicion of having swallowed a round shiny object 3
hours ago. On examination, the boy appears to be comfortable
with minimal symptoms but does point to his throat when
asked if he has any pain. A plain radiograph is shown (figure
27,1). Which of the following statements is true regarding
management of this patient?
Button batteries have a characteristic double halo appearance
on radiography that allows ready distinction from coins.
Button batteries in the stomach are rarely associated with
perforating gastric injury, although there is a report of an
infant with a gastric perforation. One patient with a gastric
button battery subsequently died from an aortoenteric fistula
from a missed esophageal injury, leading to a
recommendation for endoscopic evaluation of all button
battery ingestions with their removal. A 2010 survey of
button battery injuries included tracheoesophageal fistula
(47.9%), esophageal perforation (23.3%), esophageal
strictures (38.4%), vocal cord paralysis from recurrent
laryngeal nerve injury (9.6%), mediastinitis, cardiac arrest,
pneumothorax, and aortoenteric fistula (7 of 13 fatalities).
The presence of a button battery in the esophagus is a surgical
emergency requiring immediate esophagogastroduodenoscopy (EGD). In the EGD photo (figure 27.2), mucosal
damage is already present.
A. Distinguishing button batteries from coins is difficult via
radiography.
B. Significant esophageal stricture is an unlikely
complication.
C. Immediate removal is indicated.
D. Esophageal mucosal injury is caused by pressure effects.
E. If this object were in the stomach, it could be observed.
69
Figure 28.1. Typical presentation of pediatric intussusception.
Figure 27.2. Endoscopic image of the esophagus after disk
battery removal showing mucosal damage (arrows) along with
metallic staining (arrowheads) from ingestion of button battery.
Confirmatory testing may be considered for an
intussusception with an ultrasound, which will demonstrate a
double donut in the area intussuscepted (figure 28.2).
Follow-up EGDs are indicated. For injuries dose to the aortic
arch, MRI or CT scan should be done to rule out inflammation
tracking from the esophagus. All battery ingestions should be
reported to the National Battery Ingestion Hotline at the
National Poison Control Center, to be included in its database
(202.625.3333).
28. An 18-month-old girl presents with frequent crying spells
after periods of normal activity. Her birth and development
were normal. Immunizations are up to date. She had a lowgrade fever last week with rhinorrhea, which resolved after
72 hours. On exam, she is afebrile. Her abdominal exam is
remarkable for some guarding but no peritoneal signs. Which
of the following is the best next step in her management?
A.
B.
C.
D.
E.
Urgent laparotomy
Air contrast enema
Chest x-ray
Broad-spectrum antibiotics
Upper gastrointestinal series/small bowel followthrough
ANSWER:
B
Figure 28.2. Ultrasound demonstrating a double donut in the area
This clinical presentation is typical of pediatric
intussusception (figure 28.1). Retrospective series show an
average age at presentation of 20 months. This child does not
have peritoneal signs, and laparotomy is clearly not indicated.
Many children receive an initial plain film of the abdomen,
which is often revealing for lack of bowel gas in the right
lower quadrant. A chest x-ray will not examine this area and
is not indicated for the resolved upper respiratory symptoms.
Broadspectrum antibiotics are not indicated for a history of a
viral illness that has resolved.
intussuscepted.
An upper gastrointestinal series/small bowel follow-through
will identify the area of bowel obstruction but carries the risk
of aspiration and does not provide a means to treat the
obstruction. Air contrast enema will show the area of the
intussusception (figure 28.3) and provide a noninvasive
means of reduction. This may be done with ultrasound
guidance or with fluoroscopic imaging to assess
completeness. Recurrent intussusception rates in the first 48
hours are low, ranging from 2.7 to 6.6% in a recent meta-
70
for repair must consider this risk in addition to the risk of
testicular atrophy and incarceration without repair.
Randomized controlled clinical trials documented the greater
success of laparoscopic repair compared with open, with
fewer episodes of recurrent herniation (0.2% vs 1.0%).
Laparoscopy also allows for bilateral repair without
additional incisions. Controversy exists, however, regarding
the contralateral inguinal region in an infant presenting with
unilateral hernia. Although exceedingly low, the risk of
bilateral herniorrhaphy is to both vas deferens during the
dissection, which could result in later impotence. If the left
side is the inguinal region with a hernia, many surgeons
would argue that bilateral repair is indicated because the left
processus vaginalis normally closes first. Recent series have
failed to document a decreased incidence of occult
contralateral patent processus vaginalis or inguinal hernia
based on side of presentation (p = .099). Most authors now
advocate discussing with the parents the risk of developing a
future contralateral inguinal hernia (approximately 2.4% over
2 years) with the risk of another surgery and then deferring to
parental judgement. Sex also further confounds the issue of
whether to do a contralateral exploration in a female child.
Meta-analysis has found no significant difference in the
incidence of a patent processus or contralateral hernia in
female children compared with male children (p = .37).
Figure 28.3. Intussusception of proximal bowel.
analysis. Multiple studies document the successful
management of these patients on an outpatient basis.
29. Which of the following statements is true regarding
pediatric inguinal hernias?
30. A 5-year-old girl who weighs 17 kg presents to the
emergency department with a penetrating injury to abdomen
and evisceration of some small bowel. At exploration, she has
2 enterotomies, violation of the peritoneum in the pelvis, and
what appears to be an expanding serosanguinous fluid
collection in zone III. Her enterotomies are repaired with a
bowel resection and primary anastomosis. She has been
hemodynamically normal throughout the case. An
appropriately sized bladder catheter has been placed with
little return of urine; what has returned is bloody. What is the
next step in management?
A. Laparoscopic repair is not recommended.
B. The incidence of a patent processus vaginalis is greatest
at birth.
C. Inguinal hernias rarely incarcerate.
D. Risk of contralateral hernia is higher for male children.
E. Postoperative apnea is an expected complication in fullterm infants.
ANSWER:
B
A.
B.
C.
D.
E.
The processus vaginalis is the abdominal wall opening that
allows for the descent of the testes in utero. In girls, the
ovaries remain intra-abdominal and the round ligament lies
within the inguinal canal attached to the uterus. In both sexes,
the processus vaginalis involutes between 25 to 35 weeks of
gestational age with the left side obliterating first. Persistent
communication can result in fluid filling the scrotum
(hydrocele) or inguinal hernia because the bowel can pass
through the patent processus vaginalis. The incidence of a
patent processus vaginalis is greatest at birth and gradually
declines with age.
Angioembolization
Suprapubic drainage
Exploration of zone m
No further intervention
Pelvic packing
ANSWER:
C
This patient has an expanding fluid collection in zone HI after
a penetrating traumatic injury. The differential diagnosis
includes a vascular injury and urinary tract injury. Because
there is bloody urine output after placement of a urinary
catheter, a urologic injury must be suspected. She is
hemodynamically normal and responds to fluid resuscitation,
so it is safer to proceed even if a vascular injury is still a
concern.
Inguinal hernias can incarcerate in infants, and timely repair
is indicated. Incarceration rates are reported in 4.6 to 28% of
patients. Special circumstances, such as with the preterm
infant, need to be carefully evaluated because postoperative
apnea or need for mechanical ventilation is much more
common in this group (occurring in up to 9%). The ideal age
71
In an analysis of the national trauma databank, operative
bladder repair was associated with improved survival in 816
pediatric patients. Because angioembolization will treat only
the arterial injuries, it would not be the next step in a patient
with a suspected bladder injury. Suprapubic drainage is an
option to treat isolated bladder injuries but because a
laparotomy is under way, the recommendation is for repair in
hemodynamically normal patients. Pelvic packing might be
an option if this patient were hemodynamically abnormal
with active pelvic bleeding, but this maneuver would not
address the source of the urine leak. It could be addressed at
the time of reoperation, however. In a hemodynamically
normal patient, the next best option would be to explore zone
III.
occurred late in pregnancy, the intestines appear normal.
However, in most cases, the intestine is thickened,
edematous, and covered with exudate. Although patients with
gastroschisis do not typically have associated anomalies, the
protruded intestine is prone to vascular compromise, leading
to a higher incidence of bowel atresia.
Malrotation represents failure of normal return and rotation
of the midgut during fetal development The midgut normally
herniates into the umbilical cord during the sixth week of
development and returns to the abdominal cavity between the
10th and 12th week. As it returns, it undergoes a 270°
counterclockwise rotation along the axis of the superior
mesenteric artery. The duodenal C-loop traces the path of the
rotation, and the duodenum becomes fixed in the
retroperitoneum. If rotation is incomplete, the cecum remains
in the epigastrium, while the Ladd bands that normally fix the
cecum and duodenum to the retroperitoneum continue to
form. These bands cross from the cecum to the lateral
abdominal wall, creating the potential for duodenal
obstruction.
Items 31-33
Each lettered response may be selected once, more than once,
or not at all.
A.
B.
C.
D.
E.
Cardiac anomalies
Defect to the right of the umbilicus
Ladd bands
Cystic fibrosis
Currant jelly stool
Invagination of intestine into itself is known as
intussusception, which is the leading cause of intestinal
obstruction in children aged 6 months to 2 years.
Intussusception typically begins in the terminal ileum and
extends into the ascending or transverse colon, dragging the
associated mesentery. The majority of cases are idiopathic
and associated with a recent viral illness. Hypertrophied
Peyer patches from the terminal ileum are thought to serve as
lead points. Affected infants typically present with the sudden
onset of severe, intermittent, and cramping abdominal pain
that occurs at 15- to 20-minute intervals. Up to 70% pass stool
with a mixture of blood and mucous, giving it the appearance
of currant jelly.
31. Meconium ileus
32. Omphalocele
33. Gastroschisis
ANSWERS:
D, A, B
Cystic fibrosis in infants is associated with the production of
viscous meconium due to pancreatic enzyme deficiencies and
abnormal secretion of intestinal chloride. The thickened
meconium may become impacted in the distal ileum,
resulting in a high-grade intestinal obstruction. Affected
patients present with failure to pass meconium and
progressive abdominal distention in the neonatal period.
Diagnosis is confirmed by contrast enema, demonstrating a
microcolon. In uncomplicated meconium ileus, treatment
with water-soluble contrast agents is often successful at
relieving the obstruction.
34. A 10-year-old boy presents with 3 days of worsening
diffuse abdominal pain. A CT scan shows perforated
appendicitis with moderate diffuse peritoneal fluid. Which of
the following statements is true regarding irrigation and
suction versus suction alone of the peritoneal cavity with
laparoscopic appendectomy for perforated appendicitis?
A. There is no difference in the rate of intra-abdominal
abscess formation.
B. Irrigation reduces the number of nonpelvic intraabdominal abscesses.
C. Irrigation reduces length of stay.
D. Irrigation reduces duration of antibiotics.
E. Irrigation increases the number of abscesses per patient.
Two abdominal wall defects in the newborn—omphalocele
and gastroschisis-have different etiologies and presentations.
Omphalocele is a defect of variable size in the abdominal wall
through which bowel and solid viscera protrude but are
covered by peritoneum and amniotic membrane.
Omphalocele is thought to represent an arrest in development.
Approximately 60 to 70% of affected newborns have
associated anomalies, including cardiac anomalies in up to
40% of cases. By contrast, gastroschisis is characterized by
an anterior wall defect to the right of the umbilicus that is
usually less than 4 cm in size. Intestines freely protrude
through the defect, but there is no covering sac. If the rupture
ANSWER:
A
For decades, surgical trainees have been taught "the solution
to pollution is dilution." High-volume irrigation in patients
such as this was thought to reduce the number of abscesses
72
and improve outcome. Two recent studies addressed this
specific issue in pediatric appendicitis. In one study, children
with perforated appendicitis were randomized to suction
alone or peritoneal irrigation with a minimum of 500 mL of
saline irrigation and suction. The rate of postoperative intraabdominal abscess formation was surprisingly high, at
approximately 19%, but the same for both groups. Each group
averaged approximately 2 abscesses per patient in which they
formed. The location of abscess formation was also similar,
with almost half occurring in the pelvis. In a similar study,
the rate of intra-abdominal abscess was 4.9% and 5.0%,
respectively. The length of stay and duration of antibiotics
were similar for each group in both studies.
35. Which of the following statements is true regarding
malrotation in the pediatric population?
A. The rate of diagnosis drops off significantly after 5 years
of age
B. The incidence of subsequent volvulus is greater with
laparoscopic Ladd procedure than with an open Ladd
procedure.
C. Malrotation found incidentally in a 15-year-old does not
need to be fixed.
D. The majority of cases are diagnosed incidentally.
E. Ladd procedure includes release of Ladd bands,
broadening of the mesentery, appendectomy, and
placement of the small bowel to the left and the colon to
the right.
ANSWER:
B
Malrotation occurs in 1/6000 live births. Approximately 90%
of patients present with acute symptoms in the first year of
life. Even older children may present with lifethreatening
symptoms; therefore, an incidental finding of malrotation in
a teenager should lead to surgical management. Urgent
management of malrotation is generally performed with
laparotomy, although a laparoscopic approach is possible. All
of the components of the Ladd procedure can be performed
laparoscopically, although it appears the incidence of
recurrent volvulus is greater with a laparoscopic approach.
Whether performed open or laparoscopically, the Ladd
procedure includes untwisting of any volvulized bowel,
release of cecal bands, broadening of the small bowel
mesentery on its underside, incidental appendectomy, and
placement of the small bowel to the right and the colon to the
left.
73
Skin and Soft Tissue
Both hyperbaric oxygen therapy and intravenous
immunoglobulins are adjuncts in the treatment of necrotizing
soft tissue infection. Because there are few well-performed
studies of hyperbaric oxygen therapy in necrotizing soft
tissue infection, the value of this therapy is controversial.
There may be a mortality benefit for patients with type 1
infections; however, hyperbaric oxygen therapy should not be
initiated until all necrotic tissue is debrided. Intravenous
immunoglobulins may have a mortality benefit for patients
with type 2 (Group A streptococcal) infections but should not
be used in type 1 or 3 infections. Immunoglobulins should not
be used
ITEMS 1-24
For each question, select the best possible response.
1. A 50-year-old man with poorly controlled diabetes and a
BMI of 45 has redness and pain in his scrotum and right thigh.
His white blood cell count is 25,000/mm3 (360011,100/mm3), and he is febrile at 40.1°C. He undergoes
debridement of his scrotum and right thigh. A necrotizing
infection involving the subcutaneous tissue and fascia is
confirmed; however, the underlying muscle appeared viable.
He is admitted to the intensive care unit on vasopressors and
continued-on broad-spectrum antibiotics. Eight hours after
admission, his lactic acid increases from 5 to 8 mmol/L (2
mmol/L), his white blood cell count is 40,000/ mm3, and his
vasopressor requirement has increased. What is the next step
in his management?
A.
B.
C.
D.
E.
2. A 58-year-old woman presents after a biopsy of a right
anterior thigh Pigmented lesion. The pathology result showed
superficial spreading melanoma 1.0 mm thick; Clark level II;
no ulceration; mitosis rate 1/mm2. Her physical examination
reveals a biopsy site on the right anterior thigh with no
lymphadenopathy noted. The appropriate surgical therapy is
excision of the biopsy site with
Re-exploration in the operating room
Addition of micafungin
CT scan of the abdomen and pelvis
Hyperbaric oxygen therapy
Intravenous immunoglobulin therapy
ANSWER:
A.
B.
C.
D.
E.
A
Several risk factors for the development of a necrotizing soft
tissue infection include age older than 60, diabetes mellitus,
obesity,
intravenous
drug
abuse,
and
an
immunocompromised state. There are 3 distinct types of
necrotizing soft tissue infection. Type 1 infections are the
most common type and are polymicrobial, consisting of
Gram-positive and Gram-negative infections. Type 2
infections are caused by Group A streptococcus, and type 3
are typically caused by Clostridium species.
1-cm margin.
1-cm margin with sentinel lymph node biopsy.
2-cm margin.
2-cm margin with sentinel lymph node biopsy.
1-cm margin with groin lymphadenectomy.
ANSWER:
B
Surgical treatment of melanoma is 2-fold. First, the surgeon
must decide on the adequate margin to provide "local
control." In this patient, the depth of her melanoma is 1.0 mm.
Appropriate margin measurements for this depth would be 1
cm (table 2.1).
The mainstay of management of necrotizing soft tissue
infection is operative debridement of all involved necrotic
tissue. Complete debridement of all necrotic tissue is the most
important part of management, and most patients will require
at least 2 operative debridements to address all of the necrotic
tissue. This patient has ongoing septic shock and a worsening
inflammatory state. He should be taken back to the operating
room immediately for re-exploration and further
debridement, if necessary. Additional imaging is not
indicated unless an extension to or from the abdomen is
suspected based on operative findings
Tumor Thickness (mm)
Excision Margin (cm)
In situ
0.5-1.0
0.1-1.0
1.0
1.01-2.0
1.0 or 2.0
2.01-4.0
2.0
>4.0
2.0
Table 2.1. Recommended Surgical Margins of Excision for
Melanomas
In addition to surgical debridement, broad-spectrum
antibiotic therapy is used until culture results are available.
Coverage of Gram-negatives, Gram-positives, and anaerobes
should be ensured with antibiotic choice. A cell wall inhibitor
and a protein synthesis inhibitor should be initiated based on
local resistance patterns. An antifungal is generally not
indicated unless mucormycosis is suspected or confirmed on
culture. Amphotericin B is the drug of choice because azoles
and echinocandins do not have any efficacy against
mucormycosis.
Next, the surgeon must assess the draining lymph node basin.
This is an intermediate thickness (1-4 mm) depth melanoma.
Lymph node sampling through the use of the sentinel lymph
node biopsy technique is warranted. A 1-cm margin with
sentinel lymph node biopsy is appropriate. Other responses
combine inappropriate margins or ignore an assessment of the
lymph node drainage basin. A formed groin exploration is not
indicated with no clinical lymphadenopathy or biopsy-proven
nodal disease.
75
3. A 37-year-old man presents with a 3-mm pigmented lesion
in the nail bed of the left first toe. Biopsy confirms a
subungual melanoma in situ. What is proper treatment?
A.
B.
C.
D.
E.
for invasive tumor, amputation of the distal phalanx should
be performed.
Shave biopsy
Wide local excision
Amputation at the interphalangeal joint
Amputation at the metacarpal-phalangeal joint
Ray amputation
ANSWER:
4. Two days after starting broad-spectrum antibiotics and
debridement for a necrotizing infection of the buttock, a
patient is doing well with vitals as follows:
Temperature = 37.6°C
Heart rate = 60 beats per minute
Blood pressure = 120/56 mm Hg
Respiratory rate = 10 breaths per minute
White blood cell count = 6000/mm3 (3600-11,100/mm3)
He has a wound that appears as shown in figure 4.1. What is
the appropriate next step of management?
B
Subungual melanoma is a rare variant of malignant
melanoma, making up approximately 0.7 to 3.5% of all
melanomas. Because they are often unnoticed or
misdiagnosed, subungual melanomas tend to present with
more advanced depth. This finding led to the mistaken idea
that subungual melanomas represent a more aggressive
malignancy, which in turn led to the recommendation that
subungual melanomas should be treated with amputation of
the involved digit at the most distal interphalangeal joint.
Recognition that subungual melanomas are not more
aggressive than similar-depth melanomas challenged this
dogma. The movement is toward a more conservative, digitsparing approach that includes nail complex excision and
local flap reconstruction or application of a full-thickness
skin graft. This treatment appears to be particularly suited to
subungual melanoma in situ.
A.
B.
C.
D.
E.
An exhaustive literature review compared wide local excision
and amputation as treatment for subungual melanoma. In the
review, 82 patients from 14 studies who underwent wide local
excision were compared with 801 patients from 26 studies
who underwent amputation. The wide local excision patients
tended to have less advanced disease, with more frequent
melanoma in situ (46% vs 11%), fewer positive regional
lymph nodes, and fewer distant metastases (2.4% vs 11.3%).
In contrast, the amputation group had a lower local recurrence
rate (2.2%) than the wide local excision group (12.2%).
However, many of the wide local excision patients with local
recurrence had deep melanomas that were more appropriate
for amputation. Interestingly, regional and distant recurrences
were similar between the 2 groups (14.6% vs 13.3%).
Place wet-to-dry dressing changes
Place a vacuum-assisted closure device
Place a skin graft overlying the open muscle
Perform further debridement
Start antifungal treatment
Figure 4.1.
ANSWER:
D
Necrotizing infection is a severe nonpurulent infection
commonly caused by mixed organisms, including anaerobes,
that can lead to systemic inflammatory response syndrome
and multiorgan failure. The 3 types of necrotizing infections
are classified on the basis on the microbes found. Type 1
includes Gram-positive cocci, Gram-negative rods, and
anaerobes including Clostridium and Bacteroides. Type 2 is
usually associated with beta hemolytic Streptococcus or
Staphylococcus. Type 3 is associated with Vibrio vulnificus
and is commonly seen in SCUBA divers (associated with
infection after water exposure). After diagnosis, prompt
surgical debridement and intravenous antibiotics are the
appropriate first line of treatment for all of these infections.
After initial debridement, it is important to reassess wounds
periodically and to debride all necrotic tissues to viability
before placing a skin graft or definitive closure using
myocutaneous flaps. Although this patient appears to be
Amputation as the treatment for subungual melanoma does
not appear to provide superior outcomes compared with wide
local excision especially for in situ lesions. Randomized or
prospective studies that elucidate whether one treatment is
superior over the other for deeper lesions are still needed.
The lack of reporting Breslow depths in many of the clinical
reports make dear recommendations for treatment of deeper
lesions difficult to ascertain. An approach using lesion depth
similar to cutaneous melanoma is gaining support. Current
data imply that melanoma in situ is treated appropriately with
a digit-sparing approach. Once the conservative approach is
chosen, it is important to document complete tumor
clearance. If pathologic assessment reveals a positive margin
76
clinically normal, the presence of devitalized tissue should
immediately prompt further debridement to healthy tissues,
because rapid clinical deterioration can occur in this scenario.
follow-up of most DFSP patients but may be done for those
individuals with fibrosarcomatous DFSPs.
Ninety-five percent of DFSPs have a chromosome 17 to 22
translocation that results in a fusion mutation in platelet
derived growth factor (PDGF). Accordingly, inhibitors of
PDGF mutations, such as the tyrosine kinase inhibitor
imatinib mesylate, were studied in DFSP. In a prospective
phase II multicenter trial of imatinib given orally for 2 months
preoperatively for large or recurrent DFSPs, tumors reduced
in size in 36% of cases, which rendered some of the
subsequent operations less morbid. This and other published
evidence has led to studies of imatinib for locally advanced
and metastatic DFSP.
Fungal infections in short-duration necrotizing infections of
the soft tissue are rare, and there is no evidence to support the
use of antifungals in this setting. Although wet-to-dry
dressings can achieve simple debridement, they are not
appropriate for necrotizing infections with large amounts of
devitalized tissue. Negative pressure wound dressings (via
vacuum-assisted closure devices) improve wound healing in
large open wounds but require clean wound be
5. Which of the following statements regarding management
of dermatofibrosarcoma protuberans is true?
6. A 37-year-old woman undergoes a femoral sentinel node
biopsy for a 1.7-mm nonulcerated melanoma of the thigh.
Pathology on the single node reveals a micrometastasis. She
inquires about a completion groin node dissection. She should
be told that this procedure
A. Wide local excision with a 5-cm margin is the standard
of care.
B. Overall survival is poor.
C. The tumor is radioresistant.
D. A sentinel lymph node biopsy should be performed.
E. Imatinib can be used for locally advanced and metastatic
disease.
ANSWER:
A.
B.
C.
D.
E.
is followed by postoperative radiation.
improves disease-free survival.
does not increase her risk of lymphedema.
finds positive nodes in 50% of patients.
is combined with a pelvic node dissection.
E
ANSWER:
Dermatofibrosarcoma protuberans (DFSPs) are rare, usually
low-grade, soft tissue tumors that typically run an indolent
course. DFSPs have a slight predominance in men,
individuals aged 30 to 50 years, and truncal locations,
although they are also found on the extremities and head and
neck. Microscopically, these tumors contain spindle cells that
stain for CD34.
B
The Multicenter Sentinel Lymph Node Trial-II (MSLT-II)
randomized patients with melanoma who had
micrometastases in their sentinel nodes to completion node
dissection or observation. More than 1900 patients entered
the trial and were followed for a median of 43 months.
Although the dissection group had a slightly higher diseasefree survival (attributed mostly to control in the regional
nodes), melanoma-specific survival was the same between
groups. That is, completion dissection can decrease nodal
relapse in patients with tumors in the sentinel nodes but does
not improve overall survival. This finding was not surprising,
given that only 20% of completion dissections yield
additional tumor in the "nonsentinel" nodes (11.5% in the
MSLT-II dissection arm) and that tumor in the nodes is a
predictor but not necessarily a determinant of distant
metastases.
Many pathologists and surgeons consider the word sarcoma
in the name DFSP to be a misnomer, because the tumor has a
generally excellent survival rate and rarely metastasizes.
However, like sarcomas, DFSPs have an infiltrative nature
and thus often recur locally if not adequately excised. A
margin of 2 cm is usually recommended. Also, like sarcomas,
DFSPs are staged by size, depth, and grade. They spread to
the lungs and rarely to nodes if they do metastasize.
Therefore, sentinel lymph node biopsy is not part of routine
care of DFSPs. These tumors are sensitive to radiotherapy,
especially when given in high doses (>60 Gy). Radiotherapy
is usually reserved for tumors that recur, especially if they
become locally unresectable. However, in one study,
radiotherapy was used postoperatively and prevented local
recurrence in 12 of 14 treated patients.
Accordingly, fewer surgeons are offering completion
dissection, although patients mav still request it. Patients
must understand that these operations may improve their
nodal control rates but will not affect overall survival and are
associated with significant rates of lymphedema (24.1% in
the MSLT-II trial). If a completion groin dissection is done
for a positive sentinel node, it is not usually extended into the
pelvis, because this technique adds to the lymphedema risk
without significant benefit. Radiation therapy is not indicated
Ten to 15% of DFSPs contain a high-grade fibrosarcomatous
component. These tumors appear to account for the
approximately 2% of DFSPs that can metastasize, usually to
the lungs. Routine chest x-rays do not have a role in the
77
for positive sentinel nodes and is reserved for large nodal
tumor burden or extranodal extension.
sometimes withheld in the case of sensitive body areas such
as the hands, feet, and around the eye; in the patient presented
there is no such concern.
Conversely, no benefit of adjuvant chemotherapy is seen, and
it is usually reserved for metastatic disease. Checkpoint
inhibition (specifically by the antiprogrammed cell death-1
antibody avelumab) is of value in metastatic MCC and is
approved by the US Food and Drug Administration for the
treatment of advanced disease. This is important, because
MCC relapses in up to 48% of cases after surgery and
radiation therapy.
7. A 61-year-old man presents with the arm lesion shown in
figure 7.1. A biopsy is read as Merkel cell carcinoma.
Physical examination is otherwise unremarkable. A
metastatic workup is negative. What is the recommended
treatment?
A.
B.
C.
D.
E.
Mohs micrographic surgery
Check-point inhibitor therapy
Wide local excision only
Wide local excision and postoperative radiation
Wide local excision and postoperative chemotherapy
8. Keloids
A. do not spontaneously regress.
B. have improved cosmetic appearance after 6 weeks of
topical 5-fluorouracil.
C. more commonly occur in white patients.
D. extend beyond the margin of the original wound.
E. have excessive amounts of type III collagen.
ANSWER:
Keloids and hypertrophic scars are the result of abnormalities
in the wound healing process. Both are associated with pain,
erythema, pruritus, poor cosmesis, and restricted function. On
histologic examination, keloids extend beyond the border of
the wound. Clinically, they are noted to rarely regress and
most often recur. By contrast, hypertrophic scars extend only
to the wound edge, frequently regress, and are unlikely to
recur. Both contain excessive amounts of type I collagen in
the dermis and underlying tissue, and there is an increase in
the ratio of type I to type III
Figure 7.1.
ANSWER:
D
D
Merkel cell carcinoma (MCC) is an aggressive
neuroendocrine cutaneous tumor, arising from the Merkel
cells of the skin. Merkel cells are mechanoreceptors in the
basal layer of the dermis that lay close to nerve endings and
secrete neuropeptides in response to light touch. Thus, MCCs
stain with neuroendocrine stains. Although MCC is often
called "rare," the incidence is the United States is rising
rapidly. Series of thousands of cases have been reported.
MCCs are linked to immunosuppression and carcinogenesis
associated with a polyomavirus.
9. A 60-year-old obese man undergoes excision of an
abnormal skin lesion on his left lower leg. His physical exam
is otherwise unremarkable. He has no palpable adenopathy.
Final pathology shows a 0.85-mm thick ulcerated melanoma
with 6-mm clear margins. The most appropriate next step in
his management is
A.
B.
C.
D.
sentinel lymph node biopsy.
re-excision to a 1-cm margin.
re-excision to a 1-cm margin and sentinel node biopsy.
re-excision to a 2-cm margin and left groin node
dissection.
E. left groin node dissection.
Because they are both skin and neuroendocrine related, MCC
have features in common with both melanomas and small cell
lung cancers (SCLCs). Like melanomas, they are related to
ultra violet radiation damage and should be staged with wide
excision and sentinel node biopsy. Like SCLCs they are
sensitive to radiation therapy. Retrospective studies and a
randomized study showed that radiation therapy reduces the
local relapse rate significantly and may improve overall
survival. Thus, adjuvant radiation therapy to the primary site
after resection is the standard of care. Radiation therapy is
ANSWER:
78
C
The primary treatment for melanoma is surgical excision. The
status of the regional nodes is an important prognostic
indicator for melanoma patients. Patients with positive
sentinel nodes are known to have worse outcomes.
ANSWER:
Soft tissue masses are common, and most that are excised by
nononcologic surgeons are benign. Lesions larger than 3 cm
and those that are deep (i.e., below the subcutaneous fat),
should be considered potentially malignant soft tissue
sarcomas (STS). Ideally, these patients should be referred to
centers that have multidisciplinary teams with substantial
experience in dealing with STS before performing a
diagnostic biopsy. Some circumstances make the "ideal"
impractical, and many practitioners prefer to make a
diagnosis before a referral. If a biopsy is performed, specific
principles must be followed. Three-dimensional imaging,
preferably contrast-enhanced MRI, should be performed on
all lesions larger than 3 cm before the biopsy.
The extent of surgical excision for melanoma is guided by
pathologic depth from biopsy. The goal of melanoma surgery
is to achieve histologic negative margins and therefore
decrease risk of recurrence. The surgical margins for invasive
melanoma should be at least 1 cm for melanomas that are 1mm thick or less. For melanomas that are greater than 1 to 2
mm, adequate margins are 1 to 2 cm. For melanomas that are
thicker than 2.0 mm, margins should be 2 cm. No data support
a margin greater than 2 cm.
Sentinel lymph node biopsy (SLNB) was developed as a
procedure with less morbidity than complete node dissection.
In melanoma, the sentinel lymph nodes are identified by
injection or radioisotope and lymphoscintigraphy or injection
of blue dye in the operating room. SLNB has lower morbidity
than complete node dissection and provides information that
can direct further surgery, adjuvant therapy, and overall
prognosis. Patients with intermediate thickness melanoma
have approximately 20% risk of having a positive sentinel
node. Currently, SLNB is not recommended for patients with
Tla tumors (<1 mm in depth) but should be considered in
patients with thickness of 0.76 to 1.00 mm, especially if other
adverse parameters are present (ulceration, increased mitotic
rate, positive deep margin, young patient age). SLNB is
recommended in all patients with melanoma thickness of 1
mm or greater.
Core needle biopsy, usually multiple passes (6-8 core
specimens), should be obtained. Some centers recommend
image-guided biopsies be performed, particularly for deep
lesions. There is even a recommendation that biopsy be
guided by F-FDG-PET scanning to obtain samples from the
most metabolically active portion of the lesion. Fine needle
aspiration biopsy, while not ideal, is acceptable in the hands
of an experienced surgeon or radiologist with the back-up of
experienced sarcoma pathologists. STS rarely metastasizes
via lymphatics, and sentinel lymph node biopsy is rarely
indicated. If incisional biopsy is performed, the incision
should be placed longitudinally over the axis of the extremity
to allow for en bloc excision of the scar should re-excision of
the primary lesion be required. Meticulous hemostasis is
mandatory. This larger lesion (>3 cm) is suspicious for an
STS, and an excisional biopsy would not be appropriate.
This patient has a melanoma that is 0.85-mm thick. The
margin at time of excisional biopsy is 6 mm wide. The goal
margin for a 0.85-mm melanoma is 1 cm. Therefore, this
patient should undergo further excision of the area to achieve
wider margins. In addition, this patient meets criteria for
SLNB because the tumor is ulcerated even though the
melanoma is less than 1 mm thick. There is no indication for
a left groin dissection until SLNB is performed, and sentinel
lymph nodes are found to be positive for metastatic disease.
Traditionally, inadvertent, nononcologic resection of an STS
was thought to have a negative impact on local recurrence
risk and patient survival. Recent evidence suggests that local
recurrence is more related to the biologic aggressiveness of
the tumor and an extensive delay in performing an
oncologically appropriate re-excision. Further, overall
survival and disease-specific survival is not affected when the
reexcision is timely and meets oncologic standards, even if
residual tumor is identified.
10. A 53-year-old healthy man presents for evaluation of a
lesion located on the lateral aspect of his left thigh. He
identified the lesion approximately 6 months ago after a
minor contusion to the area while playing tennis. He states
that it has not changed in size and that it is not tender. On
physical examination, the lesion appears to be deep within the
vastus lateralis muscle, is approximately 5 cm in size, and is
hard and nonmobile. The most appropriate next step is
A.
B.
C.
D.
E.
A
11. A 52-year-old man with poorly controlled diabetes
presents with right leg pain Physical examination reveals
crepitus and a blue discoloration of the lateral aspect of the
lower extremity. His blood pressure is normal and his heart
rate is 100 beats per minute. He does have multiple blisters of
different sizes. Dorsalis pedis pulse is not palpable, but
triphasic flow is audible on a portable Doppler Plain
radiograph of the lower extremity reveals evidence of gas
tracking along the fascia. Laboratory analysis reveals
hyperglycemia, elevated Hb A1C, and leukocytosis with a
left shift. What is the first step in his treatment?
core needle biopsy.
PET scan.
fine needle aspiration.
excisional biopsy.
sentinel lymph node biopsy.
A. Tissue biopsy
B. Limited debridement
C. Hyperbaric oxygen
79
D. MRI
E. Broad-spectrum antibiotics
Variable
Value
LRINEC
Score Points
C-reactive protein (mg/L)
<150
>150
<15
0
4
0
15-25
>25
1
2
Hemoglobin (g/dL)
>13.5
0
Sodium (mmol/L)
11-13.5
<11
>135
1
2
0
Creatinine (mg/dL)
<135
≤1.6
2
0
Glucose (mg/dL)
>1.6
≤ 180
2
0
>180
1
WBCs (x 10,000 cells/mm3)
ANSWER:
E
Necrotizing
soft
tissue
infections
(NSTI)
are
characteristically severe and progress quickly. These
infections can be accompanied by sepsis, multisystem organ
failure, and death. Clinical presentation of necrotizing soft
tissue infection is accompanied by swelling and erythema.
Nonspecific skin changes include multiple blisters differing
in size, skin bullae, and gray skin coloration. Pain out of
proportion to the exam is the most consistent finding.
Crepitus is described but rarely present on exam. Laboratory
analysis can support this clinical diagnosis. Laboratory
findings are also nonspecific and should be monitored,
including serum C-reactive protein, complete blood count,
and electrolytes. These laboratory parameters are commonly
suggested to assess a patient for the risk of a NSTI. The
LINREC score is calculated to estimate the risk.
Unfortunately, a score of greater than 6 has a sensitivity of
68% and when it is greater than 8, the sensitivity is 41%.
Surgical evaluation and exploration is often required to make
a definitive diagnosis. Once necrotizing soft tissue infections
are identified, debridement should not be limited, because
prompt, wide debridement is key.
LRINEC Score
Points, Sum
≤5
Risk Category
NF Probability
Low
<50%
6-7
Intermediate
50-70%
>8
High
>50%
The LRINEC (Laboratory Risk Indicator for Necrotizing
Fasciitis) score: A tool for distinguishing necrotizing fasciitis
from other soft tissue infections.
Table 11.1. Laboratory Risk Indicator for Necrotizing
Fasciitis (LRINEC) Score System.
Imaging can facilitate diagnosis but should not delay
treatment. Gas in the soft tissues can sometimes be seen on
plain radiograph films. A CT scan with contrast can
demonstrate the lack of enhancement of the fascia and is more
specific for necrotizing soft tissue infection than air or edema.
On MRI, T2-weighted images can show focal areas of
abnormal signal intensity in the fascia. Another diagnostic
intervention that is not helpful and can delay appropriate
treatment is a tissue biopsy.
12. A 65-year-old man is diagnosed with an ulcerated 2-mm
depth melanoma, He undergoes wide local excision and
sentinel lymph node biopsy. What is the most powerful
predictor of survival?
A.
B.
C.
D.
E.
The mainstay of treatment is surgery. Delay in surgical
management increases mortality and morbidity. Rapid
surgical debridement can strongly impact outcome and
survival. All necrotic tissue should be aggressively debrided
until all remaining tissue is viable and healthy. Multiple
debridements are usually required.
Sentinel lymph node status
Breslow depth
Ulceration
Age
Site of melanoma
ANSWER:
A
Sentinel lymph node biopsy (SLNB) is used in the
management of melanoma and other cutaneous neoplasms.
The clinical utility and prognostic significance of SLNB in
melanoma patients is most clearly demonstrated in patients
with intermediate thickness melanoma, defined as 1 to 4 mm
in depth.
Early and aggressive antibiotic therapy is recommended.
Broad-spectrum empiric antibiotics directed at the most likely
organisms are necessary but should not replace surgical
debridement because the antibiotics do not penetrate dead and
dying tissue.
Hyperbaric oxygen is proposed as an adjunctive therapy after
surgical treatment. Intravenous immunoglobulins have also
been evaluated as adjunctive therapy. These are not routinely
recommended.
The Multicenter Selective Lymphadenectomy Trial (MSLTI) randomized patients to wide excision of the primary
melanoma plus SLNB or wide excision plus postoperative
nodal observation. Eligibility criteria included patients with
Clark level HI and Breslow thickness of at least 1 mm or
80
Clark level TV/V with any Breslow thickness. Patients with
intermediate thickness (1-4 mm) melanoma comprised the
primary study group. Ten-year melanoma-specific survival
rates differed by nodal status: 62.1 ± 4.8% among those with
positive sentinel lymph nodes compared with 85.1 ± 1.5%
among those with negative sentinel lymph nodes. On
multivariate analysis, including all known confounding
factors, sentinel node status was the strongest predictor of
disease recurrence or death in patients with intermediate
thickness melanoma.
In addition, among patients found to have sentinel lymph
node metastasis, the performance of further nodal dissection
was associated with improved local control and melanomaspecific survival, albeit small.
In a large retrospective study of patients with thick melanoma
reported to the Surveillance Epidemiology and End Results
program database, SLNB status provided important
prognostic information; however, performance of the SLNB
was not associated with a survival benefit.
Rating
Description
Clear
0 abscesses, 0 draining fistulas, 0 inflammatory
nodules, and 0 noninflammatory nodules
Minimal
0 abscesses, 0 draining fistulas, 0 inflammatory
nodules, and presence of noninflammatory
nodules
Mild
0 abscesses, 0 draining fistulas, and 1-4
inflammatory nodules
OR
1 abscess or draining fistula and 0 inflammatory
nodules
Moderate
0 abscesses, 0 draining
inflammatory nodules
OR
1 abscess or draining
inflammatory nodule
OR
2-5 abscesses or draining
inflammatory nodules
2-5 abscesses or draining
inflammatory nodules
Severe
Very severe
13.
The patient pictured (figure 13.1) has hidradenitis
suppurativa Which of the following statements regarding this
disease process is true?
fistulas, and ≥5
fistula
and
fistulas and <10
fistulas and ≥10
>5 abscesses or draining fistulas
Table 13.2. Hidradenitis suppurativa Physician's Global
Assessment Scale.
Medical management should be exhausted before any
surgical intervention. Medical management includes
A. This lesion represents Hurley stage II disease.
B. Medical management includes tumor necrosis factor
blockers.
C. A colostomy should be performed at the time of excision.
D. Unroofing and curettage of the sinus tracts is adequate
definitive therapy.
E. Topical antibiotics should be avoided.
•
•
•
•
•
•
Psychological screening for issues of depression,
socialization, and body image
Smoking cessation
Zinc gluconate 90 mg/day for 3 weeks
Topical resorcinol-sulfur dressing daily ad infinitum
Methylprednisolone 1-week taper
Intravenous ceftriaxone (1 dose), then oral rifampin,
moxifloxacin, metronidazole for 12 weeks, then rifampin
and moxifloxacin for 12 more weeks
If all these fail, dapsone and or cyclosporine can be
considered. Finally, consider the tissue necrosis factor
blocker adalimumab.
Surgical management includes unroofing and curettage of
sinus tracts that are persistent. This drainage or source control
helps heal the chronically inflamed tissues. Definitive
surgical management includes full-thickness excision of the
involved skin. Split-thickness skin grafting is used to cover
excised areas. Large series of perineal excisions are reported,
with only a rare need for colostomy to prevent excessive
wound soilage.
Figure 13.1.
ANSWER:
Items 14-16
Each lettered response may be selected once, more than once,
or not at all.
B
A.
B.
C.
D.
In this patient with hidradenitis suppurativa, there is a wide
area with chronic skin changes most consistent with Hurley
stage III disease implying diffuse involvement with multiple
intermediate tracts (table 13.2).
81
Antibiotics, warm compresses
Antiviral therapy, warm compresses
Incision and drainage
Nailbed removal
≥1
E. Wide debridement of involved skin and fascia
The thumb and index finger are most commonly affected.
Rapid treatment is necessary, because ischemia and necrosis
can occur. S. aureus is the most common organism.
Antibiotics and drainage are needed. To drain a felon, a
digital block is first performed. A longitudinally oriented
incision is made over the area of maximal fluctuance. Care
must be taken to not cross the distal interphalangeal joint
crease, because this can cause a flexion contracture. Probing
the wound proximally should not be done to prevent spread
of the infection into the flexor tendon sheath. The wound is
then packed loosely with gauze, and a finger splint is applied.
The hand is elevated and splinted.
14. Fluctuance under the nail bed
15. Erythema and pain with clear vesicles of the finger
16. Erythema, pain, and edema of the fingertip pulp
ANSWERS:
D, B, C
The most common cause of hand infections is trauma,
although diabetes, HTV, and malnutrition can also increase
the risk. Ninety percent of hand infections are Gram positive,
and methicillin-resistant Staphylococcus aureus is becoming
more prevalent.
Paronychia is an infection of the nail bed or the periungual
soft tissue (figure 14-16.1).
Herpetic whitlow is a viral infection of the distal finger
caused by the herpes simplex virus (HSV; figure 14-16.3).
Figure 14-16.1. Paronychia
Manicures, artificial nails, nail biting, and hangnails are
common causes. The infection usually begins on the side of
the nail bed and can spread beneath the nail if left untreated.
Initial treatment is with antibiotics and warm compresses.
Local drainage with the bevel of an 18-gauge needle or Freer
elevator may be adequate if the abscess is localized to the side
of the nail. If diagnosis is delayed, the abscess can extend
below the nail, requiring partial or complete removal of the
nail and exposure of the nail bed.
A felon is a painful, closed-space infection of the finger pulp,
most commonly caused by a puncture wound or splinter
(figure 14-16.2).
Figure 14-16.3. Herpetic whitlow.
Infection by genital (HSV-2) or oral (HSV-1) types are
clinically similar. Herpetic whitlow is most commonly found
in women with genital herpes, children with herpetic
gingivostomatitis, and healthcare workers exposed to
orotracheal secretions. Diagnosis is usually made by careful
history and physical. It is important to distinguish whitlow
from a bacterial infection because performing an incision and
drainage on a herpetic whitlow can lead to a secondary
bacterial infection and spread of the virus. Unlike a felon,
herpetic whitlow does not appear on the pulp of the digit. A
single finger is painful, erythematous, and edematous.
Vesicles appear early in the process and coalesce by day 14,
at which point it can be mistaken for a paronychia or felon.
Herpetic whitlows usually resolve in 2 to 3 weeks, and
treatment is supportive. A dry dressing should be applied and
antiviral therapy should be considered.
None of these localized infections requires wide debridement
of skin and fascia.
Figure 14-16.2. Felon of the thumb with abscess formation.
82
17. A 56-year-old hepatitis C positive shrimper presents to
the emergency department complaining of severe pain in hie
left calf. On exam, he is tachycardic, tachypneic, and
hypotensive; his left calf is purpuric with hemorrhagic bullae.
The most likely organism responsible for this presentation is
A.
B.
C.
D.
E.
Treatment of NSTIs rests on empiric broad-spectrum
antibiotic coverage and source control via radical
debridement of all infected tissue. Penicillin G with
clindamycin or metronidazole is recommended first-line
therapy. Clindamycin is preferred in type 2 NSTIs as well as
clostridial infections due to its inhibition of toxin production.
Antimicrobial coverage for type 3 NSTTs involving Vibrio
and Aeromonas species, should consist of a third-generation
cephalosporin/carbapenem and doxycycline.
Streptococcus pyogenes.
Staphylococcus aureus.
Clostridium perfringens.
Vibrio vulnificus.
Pseudomonas aeruginosa.
ANSWER:
18. A 45-year-old woman presents to the emergency
department with a 4-cm fungating necrotic wound on her
breast 10 days after an excisional breast biopsy. You suspect
pyoderma gangrenosum. Which of the following is an
associated condition with similar pathophysiology?
D
In the United States, Joseph Jones, a former Confederate
surgeon during the Civil War, was one of the first individuals
to describe necrotizing soft tissue infection (NSTI) in an 1871
report on 2642 cases of "hospital gangrene" he treated during
the conflict. The 46% mortality rate he reported has dropped
only to 25% with modem antibiotic, surgical, and critical care
therapy. Such high mortality is due, in part, to the rapid,
fulminant, and aggressive nature of these infections. With the
onset of pain, patients can progress to widespread soft tissue
necrosis, overwhelming sepsis, and death within hours. Risk
factors
for
NSTTs
include
diabetes,
obesity,
immunosuppression, malnutrition, alcohol abuse, and
intravenous drug use.
A.
B.
C.
D.
E.
Categorization of NSTIs fall into 3 types. Type 1 NSTTs are
the most common and are polymicrobial in nature. They
include aerobic and anaerobic species such as Streptococcus,
Staphylococcus,
Enterococcus,
Pseudomonas,
Enterobacteriaceae, Acinetobacter, Bacteroides, and
Clostridium. Type 2 NSTIs are monomicrobial infections
caused by Streptococcus pyogenes or Staphylococcus aureus.
They can at times occur together. Finally, type 3 infections
are monomicrobial infections caused by Clostridium
perfringens, Vibrio vulnificus, and Aeromonas species. C.
perfringens accounts for more than 70% of clostridial
infections and is sometimes classified as a type 1 NSTI. Its
alpha and theta toxins contribute to the myonecrosis and its
resultant "gas gangrene." V. vulnificus is a marine bacterium
found in raw seafood and along warm coastal areas.
Aeromonas species are found in fresh or brackish water, soil,
and wood. Hepatic dysfunction is a specific risk factor for V.
vulnificus infection.
Scalded skin syndrome
Hidradenitis suppurative
Bullous pemphigoid
Toxic epidermal necrolysis
Necrotizing soft tissue infection
Figure 18.1.
ANSWER:
B
Pyoderma gangrenosum (figure 18.2) has long been a
Early signs of NSTIs include pain out of proportion to exam,
hyperthermia, erythema, tachycardia, fever, bronzing of the
skin, anesthesia of the skin, edema, and epidermolysis.
Progression to later signs include hemorrhagic bullae, foul
odor, "dishwater" drainage, dermal gangrene, crepitus, shock,
rapid progression of erythema/pain/edema, and multisystem
organ failure. Signs particular to V. vulnificus and
Aeromonas species include fulminant development of
hemorrhagic bullae, subcutaneous bleeding, purpura,
necrosis, and gangrene.
Figure 18.2. Pyoderma gangrenosum.
83
diagnosis of exclusion has long been a diagnosis of exclusion
and is often overlooked other than in patients with known
inflammatory bowel disease, inflammatory arthritis, and
hematological disorders. Pyoderma gangrenosum represents
one of several autoinflammatory neutrophilic dermatitides
that also include aseptic febrile neutrophilic dermatosis and
hidradenitis suppurativa (figure 18.3).
Bullous pemphigoid (figure 18.4) and toxic epidermal
necrolysis (figure 18.5) are exfoliative conditions that present
Figure 18.4. Bullous pemphigoid.
Figure 18.5. Toxic epidermal necrolysis.
Figure 18.3. Hidradenitis suppurativa.
as macular papular rashes or blistering superficial wounds
similar to a second-degree bum rather than with a fungating
ulcerative lesion. Scalded skin syndrome (figure 18.6) results
from staphylococcal exotoxin-induced detachment of the
epidermal layer.
These autoimmune conditions are potentially caused by gene
mutations associated with collagen diseases, vascular
conditions (including Wegener granulomatosis), myeloid
dyscrasias, malignant tumors, and other hereditary disorders.
These noninfectious conditions are associated histologically
with dense accumulation of polymorphonuclear leukocytes
with or without vasculitis, likely due to an unregulated
interleukin-8 inflammatory response.
Postoperative pyoderma gangrenosum is a variant that
develops in surgical sites within 2 weeks postoperatively,
with a mean of 7 days after surgery. Unlike typical pyoderma
gangrenosum, which presents with lower extremity lesions,
postoperative pyoderma gangrenosum occur most commonly
in the breast, thorax, and abdomen. Postoperative pyoderma
gangrenosum remains a diagnosis of exclusion but should be
considered in the differential diagnosis of postoperative
wound dehiscence to avoid unnecessary antibiotics or further
wound debridement, especially in a patient with a personal or
family history of hematologic dyscrasia, inflammatory bowel
disease, or rheumatoid arthritis. Appropriate management
involves reducing inflammation through anti-inflammatory
and immunosuppressive therapy.
Figure 18.6. Scalded skin syndrome.
84
Clinically, it is associated with generalized erythema and
superficial epidermal peeling rather than the maculopapular
rash seen with toxic epidermal necrolysis and it lacks mucous
membrane involvement. Necrotizing soft tissue infection
(figure 18.7) represents a life-threatening, soft-tissue
infection characterized by rapidly spreading inflammation
and skin cellulitis and necrosis of the subcutaneous fat and
fascia.
Medical therapy may be appropriate for less severe disease.
Topical antibiotics such as clindamycin are associated with
significant improvement in patients with minimal or mild
disease. Systemic antibiotics are necessary in cases involving
more severe or widely spread lesions; complete response
rates of 30 to 57% occur in patients with mild disease. Other
agents such as systemic corticosteroids, dapsone, and
cyclosporin A were studied in small clinical studies with
variable results. In patients with moderate to severe
hidradenitis, the TNF alpha inhibitor adalimumab yielded a
significant reduction in PGA scores by the end of the 24th
week; however, relapse rates of up to 70% occurred.
Surgical treatment offers the best chance at lasting cure and
is currently the accepted therapy for hidradenitis, especially
in more advanced cases. Unroofing individual sinus tracts or
exteriorization by electrocauterization or curettage may be
appropriate for minimal or mild cases at fixed locations, but
both techniques are associated with a high recurrence rate in
more advanced disease. The best chance at permanent cure is
extensive removal of all affected skin and underlying tissue.
The optimal type of closure is immediate or delayed
application of a split-thickness skin graft. Primary closure is
often precluded by the extensive defect after skin excision.
Secondary intention closure requires painful dressing
changes and prolonged healing compared with skin grafting.
Figure 18.7. Necrotizing soft tissue infection.
19. A 47-year-old man has had recurrent draining sinuses in
the right axilla for many years. He now presents with 3
draining sinuses and multiple interconnected tracts across the
entire axillary area compatible with severe hidradenitis
suppurativa. The best option for surgical treatment should
consist of
20. The use of negative pressure wound therapy after burn
wound excision
A.
B.
C.
D.
E.
A. unroofing sinus tracts.
B. electrocauterization and curettage of the draining
sinuses.
C. total excision of all hair-bearing skin with primary
closure.
D. total excision of all hair-bearing skin with secondary
intention healing.
E. total excision of all hair-bearing skin with application of
a split-thickness skin graft,
ANSWER:
increases acute kidney injury.
increases use of nursing care.
increases opioid use.
decreases total treatment costs.
increases rate of skin graft take.
ANSWER:
E
Excisional therapy for bum wounds is common and often
requires skin grafting. Negative pressure wound therapy
increases local blood flow to the wound bed and improves
perfusion to wound edges and watershed areas, thus
increasing the rate of skin graft take. In addition, negative
pressure wound therapy helps reduce the exudate, edema, and
hematoma that typify these wounds.
E
Hidradenitis suppurativa is a chronic inflammatory disease
most commonly affecting the apocrine-gland-bearing skin of
the axilla, inguinal, and anogenital regions. The condition
typically presents after puberty and is characterized by
inflammatory nodules, abscesses, sinus tracts, and local
scarring. The lesions have a remitting and relapsing course
with gradual progression. Several severity classifications
schemes are proposed, but the 6-stage Physician Global
Assessment (PGA) tool is currently the most widely used
method to assess improvement in medical treatment trials
(table 13.2).
Negative pressure wound therapy allows for accurate
measurement and management of wound exudate permitting
targeted fluid resuscitation, which can decrease pulmonary
edema and acute kidney injury. An additional benefit is that
negative pressure wound therapy requires less intensive daily
nursing care to manage. Because application of negative
pressure wound therapy results in a stable wound, the need
for opioid analgesia is decreased. However, the overall cost
of using this therapy is increased due to equipment costs.
85
21. Infected pressure ulcers are common among debilitated
patients and can be difficult to treat. Which of the following
statements is true regarding the risk for clinical recurrence of
infected pressure ulcers?
alcohol and smoking status, preoperative albumin levels,
obesity, and immunosuppression status. Additional risk
factors for surgical site infections that are not modifiable
include age, recent radiotherapy, and recent skin or soft tissue
infection.
A. There is no benefit to chronic antibiotic treatment.
B. Recurrence is related to the number of surgical
debridement operations.
C. Risk is decreased by the use of negative-pressure wound
therapy.
D. Admission albumin level strongly correlates with
recurrence.
E. Risk is decreased by the use of a myocutaneous flap.
ANSWER:
Smoking has repeatedly proven to be an important risk factor
for SSIs, although the etiology of this association remains
complex and not fully understood. Nicotine causes
vasoconstriction, which is believed to lead to tissue hypoxia
and impaired nutrient delivery. A randomized trial comparing
patients who stopped smoking 6 to 8 weeks before surgery
with patients who continued to smoke demonstrated a
significant reduction in postoperative complication rates in
the nonsmoking group. The relative risk reduction for wound
complications was 83%, and the number needed to treat to
prevent an SSI was 4.
A
Debilitated patients are at a continuous risk of developing
pressure ulcers. Pressure ulcers can be difficult to treat. When
they are infected, they have a high risk of recurrence, are
associated with significant morbidity, and represent a
substantial healthcare burden. The fundamental goals of
preventing pressure ulcers are offloading pressure,
repositioning the patient, preserving the integrity of soft
tissue, and implementing risk-assessment scales.
The relationship between diabetes status and risk of SSI is
also complex. Although perioperative hyperglycemia and use
of diabetic medications are risk factors for SSIs, studies
examining hemoglobin A1C levels among surgical patients
with diabetes failed to demonstrate a correlation between
tighter glycemic control and a decrease in SSIs.
Shaving before surgery results in microscopic cuts and
abrasions. These disrupt the skin's barrier defense against
organisms and can lead to increased predisposition to
infections. Guidelines recommend against the use of razors
before surgery.
Treatment can involve nutritional supplementation, early and
aggressive local wound care including negative pressure
wound therapy, hyperbaric oxygen, surgery, and antibiotics
to treat acute infection. Despite all these treatments, the rate
of recurrence of infected pressure ulcers remains high.
Studies suggest that recurrence of infected pressure ulcers is
not related to extended duration of antibiotic therapy. In
addition, recurrence rates do not correlate with the number of
surgical debridements, surgical flaps, use of negative pressure
wound therapy, or specific regimen of antibiotics. Markers of
nutrition, such as albumin and prealbumin, are also not
associated with ulcer recurrence. Neither primary closure nor
use of myocutaneous flap correlate with recurrence. Chronic
antibiotic therapy does not reduce recurrence.
Prospective trials failed to show a decrease in SSIs with
various practice changes in the operating room, including
rescrubbing; changing outer gloves; or using new instruments
for fascial closure, redraping, and wound lavage.
Studies evaluating the relationship between postoperative
ground management and the likelihood of SSIs have had
mixed results. However, in a recent review, the timing of
dressing removal—early (defined as <48 hours
postoperatively) versus late—was not found to be associated
with the likelihood of SSI.
22. According to the American College of Surgeons and
Surgical Infection Society Surgical Site Infection Guidelines
2016 updates, which of the following reduces the risk of
surgical site infections?
A.
B.
C.
D.
E.
23. Which of the following is an early sign of a necrotizing
soft tissue infection of the lower leg?
A.
B.
C.
D.
E.
Smoking cessation 4 to 6 weeks before surgery.
Improving hemoglobin A1C
Hair removal using razors
Rescrubbing before closure in colorectal cases
Removing the surgical dressing 24 hours after surgery
Crepitus
Hemorrhagic bullae
Confluent petechiae
Hypotension
Severe pain on passive motion
ANSWER:
ANSWER:
A
E
Distinguishing necrotizing from nonnecrotizing infections is
a diagnostic challenge of general surgery. Generally
speaking, necrotizing infections require prompt tissue
Modifiable risk factors associated with the development of
surgical site infections (SSIs) include glycemic control,
86
debridement and result in wounds and functional loss. By
contrast, nonnecrotizing infections can often be treated with
antimicrobials and without surgery. Unfortunately, the hard
and definitive signs of necrotizing soft tissue infection occur
late in the disease process and after the opportunity to
minimize tissue loss and function. These hard signs include
hypotension from shock, crepitus, hemorrhagic bullae, and
confluent petechia. The latter result from tissue that is already
beyond salvage. An early sign of a necrotizing infection is
severe pain on clinical evaluation, such as passive motion of
the extremity. The pain is disproportionate to other clinical
signs. This finding should prompt further diagnostic steps to
exclude a necrotizing infection.
Surgical excision to clear margins of 4 to 10 mm is the
standard of treatment for the management of nonmelanoma
cutaneous cancers. Standard surgical excision or Mohs
micrographic surgery are both acceptable approaches. Basal
cell carcinoma constitutes approximately 80% of the
estimated 2 million nonmelanoma cutaneous cancers
diagnosed in the United States each year, with squamous cell
carcinomas making up most of the remainder. Squamous cell
carcinomas are classified as "low risk" or "high risk." Highrisk lesion characteristics include lesions greater than 2 cm on
an extremity, ill-defined borders, recurrent lesions, rapid
growth, lesion in a prior radiation field or that develop in a
chronic
wound,
neurologic
symptoms,
and
immunosuppression. Pathologic features include poor
differentiation, invasion depth greater than 2 mm (or Clark
level > IV), perineural invasion, and lymphovascular
invasion. It is unclear if high-risk lesions should have an
increased resection margin, but both patient and pathologic
characteristics should be considered when selecting either
primary or adjuvant treatment options.
24. An 83-year-old woman who is a resident of a chronic
nursing facility is referred for the lesion shown on her right
arm. Punch biopsy demonstrates squamous cell carcinoma.
She is chronically anticoagulated with warfarin for a
prosthetic mitral valve placed more than 10 years ago. Other
than severe dementia, she has no medical problems. The
lesion has become a problem because of persistent bleeding
requiring frequent dressing changes. What is the best
management option?
A surgical approach in this patient poses multiple challenges;
however, the procedure could be done with regional
anesthesia and sedation. Coverage of the surgical defect with
a primary split-thickness skin graft would address the
immediate problem of bleeding as well as the lesion itself.
A.
B.
C.
D.
Radiation therapy
Topical 5-fluorouracil
Photodynamic ablation
Local excision with coverage by a split-thickness skin
graft
E. Discontinuation of warfarin with continued dressing
changes
ANSWER:
Radiation therapy has a role in the adjuvant setting and
occasionally as a primary treatment modality. Possible
application of radiation therapy could include cosmetically
sensitive areas of the face, positive margins after primary
excision where additional tissue resection may be
inappropriate, or patients who refuse primary surgical
excision. For large tumors (>2 cm) treated with first-line
radiation therapy, the recurrence rates are more than 30%;
therefore, radiation therapy is not recommended as a first-line
option in most patients. In addition, radiation therapy for the
patient presented would involve many logistical problems
and does not immediately address the persistent bleeding
problem. Topical therapy with 5-fluorouracil or imiquimod is
appropriate for management of small premalignant lesions or
to address the field effect after a primary excision, but it is
not appropriate for large lesions such as this. The same
argument applies to photodynamic ablation. It is tempting to
discontinue the anticoagulant, but this puts the mechanical
valve at risk and does not obviate the need for continued
dressing changes.
D
Figure 24.1.
87
Surgical Critical Care Part I
possible due to the mechanism of injury, is not supported by
the radiograph and the precipitous onset of symptoms.
ITEMS 1-25
For each question, select the best possible response.
The differential diagnosis is most likely either transfusionrelated acute lung injury (TRALI) or transfusion-associated
circulatory overload (TACO). Although both conditions are
temporally related to the administration of blood products,
clinical findings can usually distinguish between the 2
conditions. The differences are summarized in table 1.2.
1. A 19-year-old, previously healthy woman was injured
after being thrown from a horse. Her only identified injury
was a comminuted right femur fracture. She underwent
internal fixation of her femur fracture 6 hours after admission
and received an intraoperative transfusion of 2 units of
packed red blood cells and 4 L of crystalloid. In the
postanesthesia care unit she developed progressive
respiratory distress manifested by air hunger, tachypnea (32
breaths per minute), tachycardia (142 beats per minute), a
blood pressure of 90/60 mm Hg, and a pulse oximeter reading
of 82% despite supplemental oxygen delivered by nasal
cannula at 12 L/minute. Breath sounds are symmetrical and
clear. There is no evidence of effusion by physical
examination. Her chest radiograph is shown (figure 1.1). The
most likely diagnosis is
A.
B.
C.
D.
E.
TRALI is a type of ALI that occurs within 6-hours of the
administration of a blood product and has the same
oxygenation criteria as ALI due to other causes (i.e.,
PaO2/FiO2 ratio <300 or saturation of <90%), in the absence
of any other identified etiology, hence a diagnosis of
exclusion. Any blood product can produce TRALI, but the
syndrome is more common with products that are plasma-rich
(e.g., fresh frozen plasma, platelet packs). Although the
syndrome is uncommon, it accounts for most transfusionrelated mortality in the United States and the developed
world. The pulmonary injury requires the activation of
neutrophils or monocytes, which are adherent to pulmonary
endothelium. The activation is thought to be caused by
antibodies in donor plasma as the result of exposure to
allogenic, but foreign, tissue during pregnancy, prior
transfusion, or tissue transplantation. When TRALI was first
recognized more than 30 years ago, it was discovered that
most donor products were from women and that most had
been pregnant. Blood banks across North America and most
of Europe instituted mitigation strategies, using only male
donors, nulliparous female donors, or women who tested
negative for human leukocyte antigens I, II, and III (HLA)
and human neutrophil antigen (HNA) for their plasma and
platelet products. That HLA- and HNA-antibodies cannot be
detected in the serum of some patients with TRALI and the
observation that not all patients who receive transfusion of
blood products known to have antibodies against the cognate
antigens develop TRALI has raised the issue of a second
potential mechanism. The hypothesis of this second
mechanism seems to impugn substances found in banked
pulmonary embolism.
aspiration of gastric content.
occult pulmonary contusion,
transfusion-related acute lung injury.
transfusion-associated circulatory overload.
Figure 1.1.
ANSWER:
Parameter
Age
Temperature
Blood pressure
TRALI
Any
Fever, usually low grade
Hypotensive, to normal
TACO
Very young and elderly
Normothermic
Hypertensive or norma1
CVP or PAOP
Response
to
Normal
Minimal to none
Elevated
Brisk
CBC
Transient leukocytosis
and thrombocytopenia
No leukocytosis
Brain
natriuretic
peptide
Normal
Elevated
diuretics
D
Acute respiratory distress in the immediate postoperative
period has multiple potential etiologies. The clinical
observations and the chest radiograph in this case suggest
some type of diffuse acute lung injury (ALI). The timing of
the observed respiratory distress and the diffuse, bilateral
infiltrates on the x-ray make a pulmonary embolism an
unlikely diagnosis. Although aspiration of gastric content is a
possibility, it is unlike to cause the immediate air hunger or
this degree of hypoxia. A pulmonary contusion, although
CVP = Central venous pressure; PAOP = pulmonary artery
occlusion pressure.
Table 1.2. Comparison of transfusion-related acute lung
injury (TRALI) and transfusion-associated circulatory
overload (TACO).
89
blood products, including cellular debris, biologically active
lipids, and soluble CD40 ligand, all associated with the
storage lesion of banked blood and blood components. These
substances can induce a proinflammatory milieu, resulting in
pulmonary dysfunction. In vitro studies and animal models of
TRALI have added support for this concept; however, human
studies have not confirmed this theory. Some researchers
implied an association with the age of the blood products, but
confirmatory clinical evidence is lacking as well.
cm (squared) x craniocaudal length in cm (which equates to
number of slices times the thickness of the CT cuts) = d 2 * L.
Periprocedural antibiotics for placement of tube
thoracostomy do not reduce the incidence of empyema or
pneumonia and are not routinely indicated when a chest tube
is placed for traumatic hemothorax.
3. A 65-year-old woman with atrial fibrillation is admitted to
the surgical intensive care unit with a subdural hematoma
after a fall. She is being treated with rivaroxaban for her atrial
fibrillation. What agent can be used to correct her
anticoagulation?
There is no specific clinical finding or laboratory test that
confirms the diagnosis and there is no specific treatment for
the syndrome. As many as 70 to 90% of patients with TRALI
will not respond to supplemental oxygen and will require
mechanical ventilation, but mortality rates are low, at
approximately 5%. The duration of respiratory dysfunction is
generally less than 72 hours in most cases.
A.
B.
C.
D.
E.
2. Regarding tube thoracostomy for a traumatic hemothorax,
A. the tube should be a 36 French chest tube.
B. the tube should be inserted at the eighth intercostal space,
just above the diaphragm.
C. placement should be preceded by intravenous antibiotics.
D. placement is not indicated for less than 300 mL of blood
in the pleural space.
E. placement is associated with a 10% complication rate.
ANSWER:
Andexanet alfa
Protamine
Vitamin K
Fresh frozen plasma
Idarucizumab
ANSWER:
A
Knowledge of which agents are used to reverse
pharmacologic anticoagulation is paramount in the
management of any patient, but particularly in patients who
sustain intracranial hemorrhage after trauma. Andexanet
alpha is used to reverse the direct oral anticoagulant (DOAC)
rivaroxaban.
D
Tube thoracostomy is one of the most common interventions
performed after trauma. Some simple concepts should be
considered to effectively drain the pleural space while
preventing complications. First, smaller tubes (28 French) are
just as effective in evacuating blood from the pleural space as
larger tubes (36 and 40 French). These smaller tubes may also
be less painful than larger caliber tubes passing through the
often-tight intercostal space. The triangle of safety for tube
placement is located at the fifth intercostal space, between the
pectoralis major and the latissimus dorsi, not at the eighth
intercostal space. Ideally the tube is directed posteriorly and
away from the fissure, but placement anywhere in the chest is
documented to be effective for drainage. Recent studies
suggest that the tube should be introduced at a less than 30°
angle from the chest wall. Finally, the chest tube should be
placed after digitally exploring the pleural space to ensure
there are no adhesions. Despite all of these suggestions, tube
thoracostomy is still associated with a 25% complication rate.
Perhaps it is this high complication rate that reinforces the
concept that chest tube placement should be avoided if less
than 300 mL of blood (small hemothorax) is in the pleural
space.
DOACs have increased in use in recent years. Compared with
Vitamin K antagonists (warfarin) for nonvalvular atrial
fibrillation and thromboembolic disease, DOACs have
predictable dose-response relationships that do not require
routine monitoring. Additionally, they have a short half-life
compared with warfarin. Rivaroxaban has a half-life of 9 to
13 hours, which means its anticoagulant activity dissipates
after 4 to 5 half-lives. Dialysis does not affect rivaroxaban's
activity because it is highly bound to proteins.
For reversal of warfarin anticoagulation, fresh frozen plasma,
prothrombin complex concentrate (containing the 4 clotting
factors that warfarin inhibits—II, VII, IX, and X), or Vitamin
K are administered. For reversal of systemic heparinization,
protamine can be given. For the other common DOAC,
dabigatran, dialysis can be performed or reversal with
idarucizumab is possible.
4. What infection control strategies can help prevent the
spread of Clostridium difficile within intensive care units?
A. Pairing of infected patients in the same room
B. Donning gown and gloves after entering the patient’s
room and discarding them after leaving the patients room
C. C Terminal cleaning of rooms with bleach after patients
are transferred
On CT imaging, a hemothorax is identified as layering fluid
within the pleural space, typically with Hounsfield units
ranging from 35 to 70. Size quantification of the hemothorax
is calculated by the following equation: volume in mL =
greatest depth of the hemothorax from chest wall to lung in
90
D. Using alcohol hand gel products before entering and after
leaving the patients room
E. E Administering of antibiotic prophylaxis with
ertapenem for any operative procedures
ANSWER:
management of this patient is vasopressor support with
norepinephrine. In Patients who have been volume
resuscitated, norepinephrine inceases the systemic and mean
arterial pressure due to vasoconstriction, with little change in
heart rate and fewer arrhythmias than dopamine.
Norepinephrine is more potent than dopamine, is more
effective in reversing hypotension, and improves outcomes in
patients with septic shock. After its initiation, norepinephrine
should be titrated to achieve a mean arterial pressure of 65
mm Hg.
C
The control of the spread of Clostridium difficile in intensive
care units is dependent on an effective infection control
strategy. Patients with C. difficile infection should be placed
on isolation precautions in a private room. Infected patients
should not be paired in the same room. The use of personal
protective equipment is mandatory for medical personnel
caring for patients with C. difficile infection. Single use gown
and gloves must be donned before entering the patient's room
and discarded before leaving the patient's room. After the
transfer of patients with C. difficile out of the intensive care
unit, the hospital room should be terminally cleaned with
bleach. The use of alcohol or gel products on the hands of
caregivers is ineffective against clostridial spores and does
not prevent the spread of C. difficile infections. Handwashing
with soap and water is the appropriate intervention to prevent
the spread of C. difficile. Antibiotic prophylaxis with
ertapenem is associated with an increased incidence of
postoperative C. difficile infection and is contraindicated in
the management and control of C. difficile infection in the
intensive care unit.
Additional crystalloid fluid in this patient is unlikely to be of
benefit because his central venous pressure of 13 cm H2O
indicates that he is not hypovolemic. Multiple clinical trials
have failed to demonstrate a benefit to the placement of a
pulmonary artery catheter in guiding the management of
patients with sepsis and septic shock. A hemoglobin
concentration greater than 7.0 g/dL provides adequate
oxygen-carrying capacity in septic patients; therefore, the
administration of additional units of red packed blood cells
would not be of benefit. The administration of hetastarch can
worsen outcomes and mortality in patients with sepsis and is
contraindicated in the treatment of septic patients.
6. Flexible bronchoscopy in intubated patients on mechanical
ventilation increases
A.
B.
C.
D.
E.
5. A 24-year-old man who weighs 100 kg is admitted to the
intensive care unit after undergoing a laparotomy for multiple
gunshot wounds to the abdomen, during which he underwent
resection of segments of his small and large bowel and repair
of multiple enterotomies. Seventy-two hours later, his
respiratory rate climbs to 40 breaths per minute. His blood
pressure is 80/40 mm Hg, his pulse is 115 beats per minute,
and his temperature is 38.7°C. His central venous pressure is
13 cm H2O. Blood, urine, and sputum specimens are sent for
Gram stain and culture testing. His lab tests are remarkable
for a white blood cell count of 22,000/mm3 (360011,200/mm3), a hemoglobin concentration of 8.0 g/dL (13517.5 g/dL), and a serum creatinine of 1.7 mg/dL (0.4-1.30
mg/dL). What intervention is appropriate in the management
of this patient?
A.
B.
C.
D.
E.
ANSWER:
D
Flexible bronchoscopy is routinely performed in intubated
patients in the intensive care unit for a variety of indications.
These indications include performing bronchoalveolar
lavage, diagnosing the etiology of lung collapse, identifying
potential sites of bleeding, or assessing the status of the
tracheobronchial tree. The performance of flexible
bronchoscopy in this setting, however, can have important
clinical consequences for patients. Prospective studies
demonstrated that flexible bronchoscopy in intubated patients
on mechanical ventilation consistently increases airway
resistance. In two-thirds of patients, flexible bronchoscopy
decreases tidal volumes. The presence of the bronchoscope
does not result in dynamic hyperinflation because of the
corresponding decrease in end-expiratory lung volumes.
Flexible bronchoscopy decreases PaO2 levels and increases
PaCO2 levels in intubated patients. After bronchoalveolar
lavage, the PaO2/FiO2 ratio may be decreased for more than
an hour. Bleeding and pneumothorax are very uncommon
after flexible bronchoscopy. Similarly, other potential
complications, including hypertension, cardiac rhythm
2000 mL of crystalloid fluid
A pulmonary artery catheter
2 units of packed red blood cells
Vasopressor support with norepinephrine
500 mL of hetastarch
ANSWER:
end expiratory lung volumes.
incidence of pneumothorax.
PaO2.
PaCO2.
tidal volume.
D
This patient has developed clinical signs of sepsis. Based on
the International Guidelines for the Management of Sepsis
and Septic shock, the most appropriate intervention in the
91
disturbances, and hemodynamic instability, are uncommon
after flexible bronchoscopy.
mechanical ventilation or a previous failed extubation. The
clinical criteria should include a spontaneous breathing trial
with respiratory pressure augmentation of 5 to 8 cm H2O
rather than a T-piece. Pressure support during a spontaneous
breathing trial of 5 to 8 cm H2O provides adequate expiratory
pressure to overcome the work of breathing imposed by the
artificial airway. The spontaneous breathing trial should be
conducted for a period of at least 30 minutes and may be
extended to 2 hours. A spontaneous breathing trial of 15
minutes is not sufficient time to assess whether a patient will
successfully tolerate extubation.
7. Noninvasive ventilation is indicated as an alternative to
mechanical ventilation in postoperative patients with
A.
B.
C.
D.
E.
upper airway obstruction.
unstable cardiac arrhythmias.
hemodynamic instability.
severe encephalopathy.
hypoxic respiratory failure.
ANSWER:
For patients who are at high risk for extubation failure after
receiving mechanical ventilation for more than 24 hours and
who pass a spontaneous breathing trial, the use of
noninvasive ventilation is recommended to help prevent the
need for reintubation. Prophylactic flexible bronchoscopy is
not recommended to remove retained secretions, because it
does not improve the likelihood the patient will successfully
tolerate extubation. A cuff leak test should be performed on
mechanically ventilated patients who otherwise meet criteria
for extubation but who are deemed to be at high risk for postextubation stridor. This particularly applies to patients who
have required reintubation after self-extubation. Patients who
do not have evidence of audible breathing after deflation of
the cuff of the endotracheal tube should receive systemic
steroids at least 4 hours before an attempt at extubation.
E
In a prospective observational study of patients with
respiratory failure after abdominal surgery, noninvasive
ventilation markedly reduced the incidence of reintubation,
length of hospital stay, and mortality. A trial of noninvasive
ventilation, rather than reintubation, is recommended as the
initial intervention for surgical patients with postoperative
acute respiratory failure.
Noninvasive ventilation requires the presence of an intact
airway. Therefore, the use of noninvasive ventilation is
contraindicated in the setting of upper airway obstruction or
severe encephalopathy in which patients are not able to
protect their airways. Similarly, noninvasive ventilation is
contraindicated in the setting of unstable cardiac arrhythmias
or hemodynamic instability where the airway needs to be
secured with an endotracheal tube should the rapid institution
of advanced cardiac life support be required.
9. Which of the following parameters is required to
characterize acute respiratory distress syndrome based on the
current definition of this condition?
A.
B.
C.
D.
E.
8. A 37-year-old woman develops severe acute respiratory
distress syndrome after undergoing multiple laparotomies for
resection of her small bowel. After 10 days of mechanical
ventilation, she extubates herself and requires emergency reintubation for stridor and acute respiratory distress. She
remains intubated for an additional 8 days, during which time
her pulmonary function and chest x-ray improve
significantly. What is most likely to optimize her chances for
successful extubation?
ANSWER:
E
Acute lung injury and acute respiratory distress syndrome
(ARDS) are notoriously difficult to define and diagnose. First
described in the 1960s, ARDS is a form of nonhydrostatic
pulmonary edema resulting from a primary pulmonary insult
or a pulmonary response to extra pulmonary sources of
inflammation. The result of this pulmonary insult is hypoxia,
bilateral pulmonary opacities on chest radiograph, poor
pulmonary compliance, and increased dead space ventilation.
Initial definitions of ARDS focused on the hypoxia, the
absence of elevated filling pressures, and the radiographic
changes. The exclusion of other causes for hypoxemia was
another aspect. Multiple terms were used in addition to
ARDS to describe the pulmonary insult, including pulmonary
dysfunction and acute lung injury of varying severity.
A. Spontaneous breathing trial using a T-piece
B. Limiting spontaneous breathing trial to 15 minutes
C. Avoiding the use of noninvasive ventilation following
extubation
D. Prophylactic flexible bronchoscopy to remove retained
secretions
E. Systemic steroids if a cuff leak is not present
ANSWER:
Pulmonary artery wedge pressure
Pulmonary vascular resistance
Mean airway pressure
Plateau pressure
Positive end expiratory pressure
E
Clinical criteria can help determine whether a patient can
remain successfully extubated after an extended period of
92
Introduced in 2012, the Berlin Definition of ARDS replaced
the term "acute lung injury" with a spectrum of ARDS
severity based upon PaO2/FiO2 (P/F) ratio. This revision
included a P/F ratio of 200 to 300 as mild with a mortality
rate averaging 27%, 100 to 200 as moderate with a mortality
rate of 32%, and less than 100 as severe with a mortality rate
of 45%. All these calculations are done on a positive endexpiratory pressure (PEEP) of at least 5 cm H2O. This period
of hypoxia also must occur within 7 days of the inciting insult.
E. Start hydrocortisone
ANSWER:
Propofol is a popular medication for maintaining sedation in
the intensive care unit. Its short half-life is particularly
attractive for use in traumatic brain injury. Unfortunately, the
use of propofol for prolonged periods (>48 hours) or at high
doses is associated with the rare but potentially fatal propofol
infusion syndrome. There is no widely accepted definition of
this syndrome, and its pathogenesis has yet to be fully
delineated but may be caused by impaired mitochondrial
function. Propofol infusion syndrome typically involves
various combinations of unexplained metabolic acidosis,
rhabdomyolysis, hyperkalemia, hepatomegaly, renal failure,
hyperlipidemia, arrhythmia, bradycardia, and rapid
progression to cardiac failure.
Only PEEP is a component of the Berlin Definition of ARDS.
Initial definitions used a pulmonary wedge pressure of less
than 18 mm Hg, but this was deleted in the Berlin criteria.
Pulmonary vascular resistance, mean airway pressure, and
plateau pressure were never included in an ARDS definition.
10. The proper duration of antibiotics for a ventilatorassociated pneumonia caused by Klebsiella pneumoniae is
The treatment is discontinuation of the propofol,
hemodialysis, organ support, and sustainment of
cardiopulmonary function. Propofol is also associated with
the development of hypertriglyceridemia. The significance of
this abnormality is controversial but may be an etiology of
pancreatitis. Dexmedetomidine, a sedative agent used in the
intensive care unit, can be used in place of propofol but it will
not correct propofol infusion syndrome if propofol is
continued. Dexmedetomidine may induce bradycardia.
Hydrocortisone would be appropriate if this patient had acute
adrenal insufficiency, typically manifested by hypotension
refractory to fluids and vasoactive agents.
A.
B.
C.
D.
8 days.
15 days.
until the x-ray has cleared.
until fever has resolved and white blood cell count has
normalized.
E. until the patient is liberated from the ventilator.
ANSWER:
A
Few things in medicine are supported by well-controlled
randomized trials. The duration of antibiotic therapy for
ventilator associated pneumonia, however, is supported with
good data and strong recommendations from the Infectious
Disease Society of America and the American Thoracic
Society. A short course of 7 to 8 days is as safe and effective
as a 14- to 15-day course. The chest x-ray in intensive care
unit patients can be nonspecific, and its normalization can lag
behind the resolution of the pneumonia. Fever and
leukocytosis in the intensive care unit patient are also
nonspecific. Patients can be dependent on mechanical
ventilation for many reasons, and continuation of antibiotics
for the duration of ventilation is not necessary.
Fentanyl is another commonly used medication in the
intensive care unit that is known to cause chest wall rigidity
at high doses. Levetiracetam is used to prevent posttraumatic
seizures. Its adverse effects consist of somnolence, decreased
energy, headache, dizziness, coordination difficulties, and, in
rare cases, Stevens-Johnson syndrome and toxic epidermal
necrolysis.
ITEMS 12-13
12. An 18-year-old man with a gunshot wound to the head is
intubated in the intensive care unit. He has no response to
pain, a Glasgow Coma Scale score of 3, no pupillary
response, no gag reflex, and no corneal reflex. He does not
have spontaneous respirations. Which of the following
findings would prevent a brain death examination being
performed?
11. 67-year-old woman sustained a traumatic brain injury
after a motorcycle crash. She is sedated with propofol and
fentanyl, receives levetiracetam as seizure prophylaxis, and
has been continued on her statin and aspirin. On postinjury
day 11, she has decreased urine output, hyperkalemia, and a
metabolic acidosis. Her creatine phosphokinase is greater
than 10,000 IU/L (60-174IU/L). What is the best first step in
her management?
A.
B.
C.
D.
A
A.
B.
C.
D.
E.
Discontinue the propofol
Discontinue the fentanyl
Discontinue the levetiracetam
Start dexmedetomidine
93
Blood pressure = 106/70 mm Hg on norepinephrine drip
Hemoglobin = 8.1 g/dL (13.5-17.5 g/dL)
Sodium - 161 mEq/L (136-14.5 mEq/L)
Temperature = 36.5°C
White blood cell count = 15,200/mm3 (360011,200/mm3)
13. You elect to perform an apnea test to confirm brain death
after correcting all physiologic derangements. His pretesting
vital signs and arterial blood gas on 100% FiO2 are as
follows:
("doll's eyes") and the vestibulo-ocular reflex ("cold
calorics"). The patient should have no corneal, gag, or cough
reflexes and no spontaneous respiratory effort.
Fourth, an apnea test is performed. Although the American
Academy of Neurology guidelines support a single apnea test,
local laws and regulations dictate whether 1 or 2 apnea tests
are required. The theory behind the apnea test is that
respiratory drive is based on PaCO2 levels. An abnormally
high level should trigger a respiratory effort in any patient
capable of doing so. Ongoing apnea in the presence of
hypercarbia indicates brain death. First, the patient is
preoxygenated with 100% O2 for 10 to 15 minutes. Next, the
ventilator is adjusted to obtain a PaCO2 as dose as possible to
40 mm Hg. A baseline arterial blood gas is then drawn. The
endotracheal tube is disconnected from the ventilator and a
smaller nasal cannula tube is connected to 5 to 6 L/minute
oxygen and inserted into the endotracheal tube. If
spontaneous respirations, desaturation less than 85%, or
hemodynamic instability occur, the apnea test is aborted.
After 10 minutes, an arterial blood gas is drawn. A PaCO2
greater than 60 mm Hg (or 20 mm Hg above baseline) is
considered positive, and the patient is declared brain dead.
Blood pressure = 114/70 mm Hg
Heart rate = 110 beats per minute
O2 saturation = 98%
pH = 7.38
PaCO2 = 42mmHg PaO2 = 278 mm Hg
IHCO3 = 24 mEq/L (20-29 mEq/L)
During his apnea test he is administered 100% supplemental
O2, and no spontaneous respirations are noted. Which of the
following findings would confirm brain death after a 10minute apnea test?
A.
B.
C.
D.
E.
Blood pressure = 100/40 mm Hg
PaCO2 = 66mmHg
HCO3 = 18
pH = 7.30
PaO2 = 200mmHg
ANSWER:
C, B
Ancillary tests are not required and should be used only if the
patient is unable to complete the apnea test or any of the other
exam findings are equivocal. The American Academy of
Neurology recognizes 4-vessel angiography, nuclear
perfusion imaging ("cerebral blood flow scan"), transcranial
Doppler, and electroencephalography as acceptable ancillary
tests.
In this patient, hypernatremia can contribute to coma and
should be corrected before performing a brain death exam.
Vasopressor use is not a contraindication if the blood pressure
remains above 90 to 100 mm Hg. A hemoglobin level of 8.1
g/dL and a temperature of 36.5°C are not contraindications to
performing a brain death exam. Simple leukocytosis is
common in critically ill patients, and its presence alone is not
a contraindication.
14. A 64-year-old man is recovering in the intensive care
unit 6 hours after an exploratory laparotomy and Hartmann
procedure for perforated diverticulitis with feculent
peritonitis. He remains intubated since the procedure. He has
no history of cardiac or pulmonary disease or symptoms. He
has made 30 mL/hour of urine since the operation. His vitals
since the operation have been as follows: heart rate 80 to 100
beats per minute and systolic blood pressure 130 to 150 mm
Hg. He now has a heart rate of 160 beats per minute and blood
pressure of 115/60 mm Hg. Electrocardiogram demonstrates
atrial fibrillation without ST elevation or depression. What is
the most appropriate next step in management?
Four steps are required for brain death declaration. First, the
patient must have a cause of irreversible coma identified,
usually by history and physical examination with imaging
confirmation. A period of time from admission to
performance of the brain death examination should be
allowed to confirm that the patient's clinical status is not
improving. This period of time is not specified in most
guidelines but is generally between 6 and 24 hours after
admission.
Second,
confounding
physiologic
and
metabolic
derangements should be identified and corrected. The patient
should be normothermic and normotensive, although
vasopressor support is allowed. Any intoxicants should be
cleared, and medications that could obscure the clinical exam
should be discontinued for at least 5 half-lives. Electrolyte
abnormalities should be corrected. Glucose levels should be
within normal parameters.
A.
B.
C.
D.
E.
Metoprolol
Nicardipine
C. Electrocardioversion
D. Echocardiography
Digoxin
ANSWER:
Third, a physician experienced in assessing for brain death
should perform a physical examination. The Glasgow Coma
Scale should be 3 and cranial nerve reflexes should be absent.
The patient should have no response to painful stimuli, and
the pupils should be fixed and nonreactive to light. The eyes
should remain in midposition with the cervico-ocular reflex
A
Atrial fibrillation is the most common postoperative cardiac
arrhythmia and may occur in up to 26% of patients
undergoing noncardiac nonthoracic surgery. The incidence
varies greatly with patient risk factors, such as age, preexisting cardiac disease, other co-morbidities, and the type of
94
surgery performed. It is thought to occur primarily due to
adrenergic stimulation as well as systemic inflammation,
fluid shifts, or electrolyte abnormalities. Typically, atrial
fibrillation develops between day 1 and 4 after surgery and is
self-limited. Treatment and management is the same as in the
nonsurgical setting and primarily involves rate control and
electrolyte correction unless the patient is hemodynamically
compromised.
sedation spend more time on the ventilator than those
receiving intermittent sedation as needed. Regardless of the
time on the ventilator, the use of spontaneous breathing trials
in conjunction with "daily sedation holidays" has the greatest
effect on decreasing ventilator days.
Regardless of the medication used or ventilator mode,
protocols that discontinue sedation and allow for assessment
for extubation lead to improved outcomes. The weaning trial
should include parameters for extubation, including
appropriate vital capacity, tidal volume, respiratory rate,
negative inspiratory force, and rapid shallow breathing index
to help predict successful extubation. Tracheostomy is not
used 24 hours after an exploratory laparotomy.
Cardiac biomarkers and an electrocardiogram should be
obtained to rule out an acute coronary event as the
precipitating factor. Echocardiography is generally not
recommended unless there is concern for underlying cardiac
disease or dysfunction. The hemodynamically compromised
patient should undergo immediate synchronized direct
current cardioversion. Intravenous amiodarone may be
administered if there is a delay in being able to perform
cardioversion. Hemodynamically normal patients should
have their ventricular rate controlled. When considering
which agent to use, it is important to determine whether the
patient has underlying chronic obstructive pulmonary
disease, heart failure, or a reduced ejection fraction. Options
for
intravenous
agents
include
beta-blockers,
nondihydropyridine calcium channel blockers, digoxin, or
amiodarone.
16. Which of the following interventions improves survival
in a patient with moderate to severe acute respiratory distress
syndrome?
A. High-frequency oscillatory ventilation, early physical
therapy, and bronchoscopy
B. High tidal volume mechanical ventilation, early
neuromuscular blockade, and inhaled nitric oxide
C. High tidal volume mechanical ventilation, recruitment
maneuvers, and bronchoscopy
D. Low tidal volume mechanical ventilation, early
neuromuscular blockade, and prone positioning
E. Low tidal volume mechanical ventilation, high-dose
steroids, and inhaled nitric oxide
When not contraindicated due to underlying disease, betablockers are first-line therapy given the underlying adrenergic
stimulation that is the most likely cause of the atrial
fibrillation. Nicardipine is not commonly used to treat cardiac
arrhythmias; it is used to treat cerebral hypertension after
cerebral aneurism rupture. Digoxin could be used, but its
onset of action is too slow.
ANSWER:
The landmark ARDSNet trial demonstrated that low tidal
volume ventilator settings (6 mL/kg vs 12 mL/kg ideal body
weight) significantly improved survival in patients with any
degree of acute respiratory distress syndrome (ARDS; 31%
vs 40%). Thus, How stretch" ventilator management with low
tidal volumes and escalating doses of positive end-expiratory
pressure still stands as the cornerstone of ARDS management
Two other therapies have since been found to improve
mortality in patients with moderate to severe ARDS in single
randomized-controlled trials: a short course of neuromuscular
blockade (*48 hours) early in the course of ARDS and prone
positioning.
15. A 60-year-old man is currently sedated and intubated 24
hours after an exploratory laparotomy for strangulated bowel
due to an internal hernia. He is receiving propofol and
fentanyl for sedation and analgesia. With regard to his
pulmonary management, what intervention is most likely to
lead to earlier liberation from the ventilator?
A.
B.
C.
D.
E.
Daily sedation holiday
Use of propofol
Measurement of rapid shallow breathing index
Early tracheostomy
Assist control ventilation
ANSWER:
D
Two recent trials showed high-frequency oscillatory
ventilation (HFOV) did not improve outcomes in ARDS and
may even increase harm. Although physical therapy should
be considered in all intensive care unit patients, even those on
mechanical ventilation, there is no proven mortality benefit
or improved long-term outcomes in ARDS patients.
Fiberoptic bronchoscopy is clinically useful and is a very
practical tool in routine intensive care unit care; however, no
specific mortality benefit has been identified in patients with
ARDS. High tidal volume mechanical ventilation should be
explicitly avoided in ARDS patients and in routine use of
A
The decision to liberate a patient from the ventilator is
challenging and should be revisited on a frequent basis to
decrease ventilator time. The benefits of shortened ventilator
time include shorter hospital stay and intensive care unit
length of stay, decreased morbidity, and decreased mortality.
A significant factor in managing intubated patients is the
overuse of sedation. Patients on continuous intravenous
95
mechanical ventilation in the operating room and intensive
care unit for patients without respiratory failure. Inhaled nitric
oxide is a potent pulmonary vasodilator that can improve
ventilation/perfusion ratio mismatch and thereby improve
oxygenation. However, its use is associated with increased
acute kidney injury; therefore, it should be used as a very
short-term rescue therapy until more labor-intensive therapies
such as prone positioning can be instituted.
approaching 25%. Necrosectomy is currently recommended
only if radiologic and endoscopic drainage procedures fail.
Less-invasive approaches, like percutaneous drainage done
by interventional radiology and endoscopy with
necrosectomy or transgastric drainage combined with
percutaneous drainage, result in less requirement for open
surgery, shorter hospital stays, and less morbidity. The stepup procedure combines percutaneous drains that are gradually
up-sized to the point where minimally invasive
retroperitoneal necrosectomy can be performed via the drain
tracks if necessary to remove larger pieces of necrotic tissue.
Likewise, recruitment maneuvers can open atelectatic lung
segments and may result in a transient improvement in
oxygenation, but this comes at the cost of potentially inducing
barotrauma or volutrauma that may have longer-term adverse
effects. Finally, although some limited data suggest a
potential benefit to high-dose systemic steroids in early
ARDS, the risks and complications associated with this
therapy are currently thought to outweigh any potential
benefit. The exceptions include ARDS due to eosinophilic
pneumonia and select patients with community-acquired
bacterial pneumonia.
18.
A 64-year-old man undergoes elective
pancreaticoduodenectomy for adenocarcinoma. On the night
of postoperative day 1, he becomes diaphoretic, confused,
and anxious. His heart rate ranges from 130 to 165 beats per
minute, with an irregular rhythm. His blood pressure is 88/60
mm Hg. He has no prior history of arrhythmias, and his
preoperative electrocardiogram showed normal sinus rhythm.
What is the best way to manage this patient' clinical
condition?
17. Which of the following statements regarding the
management of a patient with necrotizing pancreatitis is true?
A.
B.
C.
D.
E.
A. Mortality is greater than 30%.
B. Infected pancreatic necrosis increases mortality to 50%.
C. Open surgical necrosectomy remains the treatment of
choice.
D. Intervention is reserved primarily for those with
symptomatic clinical deterioration.
E. Percutaneous and endoscopic drainage techniques are
not appropriate.
ANSWER:
Direct current cardioversion
Esmolol
Adenosine
Diltiazem
Amiodarone
ANSWER:
A
Postoperative atrial fibrillation in noncardiac surgery patients
generally occurs within the first 4 days. The etiology of
postoperative atrial fibrillation is likely multifactorial;
however, commonly cited causes are increased circulating
catecholamine levels, increased sympathetic tone,
hypervolemia, and electrolyte abnormalities. Atrial
fibrillation is characterized by an irregular rhythm, without
distinct P waves on electrocardiogram, and a ventricular
response between 90 to 170 beats per minute.
D
Acute pancreatitis is a common cause of gastrointestinal
complaints that brings patients to the emergency department.
Although most cases are mild or moderate in severity and are
associated with a low morbidity and mortality, severe acute
pancreatitis, which involves the failure of one or more organs
over 48 hours has a mortality rate upward of 25%.
Necrotizing pancreatitis involves necrosis of more than 30%
of pancreatic parenchyma or peripancreatic tissue and
accounts for only 10 to 15% of acute pancreatitis cases. It is
routinely diagnosed with a CT scan with intravenous contrast.
Patients who have atrial fibrillation with rapid ventricular
response can present with hypotension or shock due to
inadequate cardiac output Signs of shock and hemodynamic
instability in atrial fibrillation are hypotension, acute chest
pain, confusion, and heart failure. Rapid treatment of atrial
fibrillation is required, usually by direct current cardioversion
attempting to achieve normal sinus rhythm. The overall
success rate of direct current cardioversion is 90%, but the
success rate decreases as the duration of atrial fibrillation
increases. Some patients may need concurrent treatment with
an antiarrhythmic drug such as amiodarone or sotalol before
direct current conversion to prevent relapse of atrial
fibrillation; however, direct current conversion should not be
delayed in hemodynamically abnormal patients.
A key distinction in these patients is the presence or absence
of infected necrosis, because noninfected necrotizing
pancreatitis has a mortality rate of 15% versus 30% in
infected necrotizing pancreatitis. Intervention for sterile
necrotizing pancreatitis is optimally delayed, because twothirds will remain sterile and ultimately resolve over time.
Historically, necrosectomy was a common surgical approach
for dealing with infected necrotizing pancreatitis, and it was
fraught with morbidity rates up to 95% and mortality rates
96
Pharmacologic therapy is preferred in patients with atrial
fibrillation with rapid ventricular response who are
hemodynamically normal. There is no difference in long-term
outcomes comparing drugs aimed at rate control versus
rhythm control. The goal of therapy in postoperative atrial
fibrillation is ventricular rate of 80 to 100 beats per minute,
even if the patient remains in atrial fibrillation. The first-line
therapy is generally directed toward atrioventricular node
blockade. Beta-blocker therapy is suggested as a first-line
agent in postoperative atrial fibrillation due to increased
sympathetic tone and circulation catecholamines in the
postoperative period. However, calcium channel blockers
remain a commonly used class of drugs.
outcomes in patients who had tight blood glucose control,
between 80 and 110 mg/dL. Although tight glycemic control
was rapidly adopted in critically ill patients, subsequent trials
had conflicting results across diverse patient groups. A large
multicenter prospective randomized trial reported increased
mortality in a tightly controlled group, mainly from episodes
of hypoglycemia.
Based on these findings, the Society for Critical Care
Medicine recommended monitoring blood glucose levels but
warned against tight glycemic control. A blood glucose level
of 150 mg/dL should prompt intervention with a goal of
keeping the blood glucose level less than 180 mg/dL. The
initial method of glucose control should be an intravenous
insulin infusion. This allows for close monitoring and
adjustments of the insulin infusion until a stable nutritional
regimen can be initiated. Metformin is a long-acting oral
antihyperglycemic agent and is inappropriate for the acute
management of hyperglycemia. Insulin glargine is a longacting agent that does not allow for rapid titration of serum
glucose.
Either beta-blocker or calcium channel blockers can be used
as a first-line agent; however, caution should be taken when
combining the 2 drugs because they both slow the
atrioventricular node and can lead to heart block when given
together. If the patient is still in atrial fibrillation with rapid
ventricular response after an atrioventricular node agent has
been given, amiodarone is another potential agent.
Amiodarone acts through several mechanisms to slow the
ventricular rate and may convert the patient to sinus rhythm.
Given amiodarone's large volume of distribution, a loading
dose followed by intravenous infusion is needed to see a
clinical effect. Adenosine is not used in patients with atrial
fibrillation; it can be used for diagnosis or treatment of other
supraventricular tachycardias.
20. A 40-year-old man presents with choledocholithiasis and
an elevated serum bilirubin. He undergoes an endoscopic
retrograde cholangiopancreatography, which successfully
clears the stone from his common bile duct. The following
day, he develops severe epigastric pain and has a lipase of
2500 U/L (10-140 2500 U/L). A CT scan of his abdomen and
pelvis shows necrotizing pancreatitis (figure 20.1). What is
the best method to decrease his risk of progression to infected
necrotizing pancreatitis?
19. A 40-year-old otherwise healthy man is an unrestrained
driver in a motor vehicle crash. He arrives with a Glasgow
Coma Scale score of 3 and blood pressure of 90/60 mm Hg.
He has a positive focused assessment with sonography for
trauma exam and is taken for an exploratory laparotomy and
splenectomy. During his initial admission labs to the
intensive care unit, his glucose level is 145 mg/dL (70—100
mg/dL). Subsequent point of care blood glucoses for 24 hours
are greater than 200 mg/dL. How should this patient's blood
glucose levels be managed?
A.
B.
C.
D.
E.
Early enteral nutrition
Probiotics
Intravenous antibiotics
Intravenous corticosteroids
Parenteral nutrition
A. Insulin infusion to maintain blood glucose levels
between 150 and 180 mg/dL
B. Subcutaneous insulin sliding scale at blood glucose of
210 mg/dL
C. Insulin infusion to maintain blood glucose levels
between 80 and 110 mg/dL
D. Subcutaneous insulin glargine 0.3 mg/kg
E. Oral metformin
ANSWER:
A
Hyperglycemia is associated with adverse outcome in
critically ill patients. Observational data showed increased
infections and mortality in patients with hyperglycemia,
especially in patients on parenteral nutrition. A single
institution randomized controlled trial showed improved
Figure 20.1.
97
ANSWER:
necrosis. Enteral nutrition is thought to enhance the integrity
of the mucosal barrier and reduce the translocation of bacteria
systemically. A meta-analysis of 5 randomized controlled
trials of enteral versus parental nutrition in patients with
severe acute pancreatitis showed a decreased incidence of
pancreatic infections and mortality with early (defined as
within 3 days) enteral nutrition. The IAP and APA
recommend early tube feeding to reduce the risks of infection
and mortality. Parenteral nutrition is associated with worse
outcomes and should be used only if enteral feeding is not
tolerated.
A
Infected necrotizing pancreatitis is a rare but dreaded
complication of acute pancreatitis. The nomenclature
surrounding acute pancreatitis was clarified in a revision of
the Atlanta Classification in 2012. Severe acute pancreatitis
is defined as single or multiple organ failure for more than 48
hours. Necrotizing pancreatitis is diagnosed via contrastenhanced CT scan; areas of the pancreas that do not enhance
with contrast are presumed to be necrotic (figure 20.2).
21. In patients with traumatic brain injury (head abbreviated
injury score >3), venous thromboembolus (VTE) prophylaxis
with low molecular weight heparin compared with
unfractionated heparin results in
A. increased mortality.
B. decreased bleeding complications.
C. increased unplanned returns to operating room.
D. increased incidence of heparin-induced thrombocytopenia.
E. decreased VTE rate.
ANSWER:
E
Venous thromboembolism (VTE) prophylaxis in traumatic
brain injury patients is particularly challenging. Severe
traumatic brain injury patients are at increased risk for VTE
due to their immobility. They may also have a relative
contraindication to chemical prophylaxis due to the presence
of intracranial hemorrhage. Thus, the risk of VTE must be
balanced against the risk of hemorrhage progression. Most
data now suggest that chemical VTE prophylaxis can be
started within 72 hours of a stable head CT scan. Another
major question is the preferable agent for chemoprophylaxis:
unfractionated heparin or low molecular weight heparin.
Figure 20.2. Necrotizing pancreatitis. Areas of the pancreas that
do not enhance with contrast are presumed to be necrotic.
The distinction between necrotizing pancreatitis and infected
necrotizing pancreatitis can be challenging to make. Patients
with progression to infection will often have a worsening
clinical course and CT scan findings of extraluminal gas in
the collection. A fine needle aspirate can be performed to
confirm the diagnosis but is not required to begin treatment.
The progression to infected pancreatic necrosis is associated
with increased morbidity and mortality. To reduce the rate of
infection, systemic antibiotics were used as prophylaxis.
Prospective randomized trials provided mixed data regarding
the efficacy of routine antibiotic use in necrotizing
pancreatitis. A meta-analysis of 14 trials of patients with
severe acute pancreatitis did not support prophylactic
antibiotic use. The guidelines from the International
Association of Pancreatology and American Pancreatic
Association (IAP/APA) recommend against intravenous
antibiotic prophylaxis. Probiotics have been studied
prospectively; however, no reduction in infection rates have
been noted. There is also no evidence that intravenous
steroids reduce the rate of conversion to infected pancreatic
necrosis.
For patients with traumatic brain injury, use of low molecular
weight heparin for VTE prophylaxis results in lower odds
ratio of VTE and lower mortality compared with
unfractionated heparin. There is no difference between the 2
agents with regard to bleeding risk or unplanned return to the
operating room. Heparin-induced thrombocytopenia occurs
up to 10 times more often with unfractionated heparin
compared with low molecular weight heparin. Low molecular
weight heparin should be used with caution in patients with
renal insufficiency.
22. A 58-year-old woman has been in the intensive care unit
on mechanical ventilation (rate set at 12, breathing at 22) for
8 days after sustaining multiple rib fractures. She is being
treated for pneumonia and develops sepsis. She is oliguric
(urine output 0.3 mL/kg/hour x 2 hours) despite 2 L of fluid.
She is being monitored by echocardiography. Which of the
Both animal and human studies have implicated failure of the
gut mucosal barrier in the development of infected pancreatic
98
following bedside tests is the best predictor of fluid
responsiveness in this patient?
A.
B.
C.
D.
E.
Delirium, a state of acute decline in cognitive function, is a
clinical diagnosis common in elderly hospitalized patients.
However, it remains poorly understood and often
undiagnosed by healthcare providers. Delirium is associated
with high rates of adverse outcome and mortality; it may be
caused by a single factor, but in the older patient, the cause of
delirium is frequently multifactorial due to the presence of
comorbid conditions, polypharmacy, and physiologic
decline. The older patient is vulnerable to potential insults,
wherein a single dose of medication may precipitate delirium.
Similarly, surgery is a risk factor for delirium in the elderly.
Among the leading risk factors for delirium in both medical
and noncardiac surgery patients are age greater than 70 years,
existing cognitive or functional impairment, vision
impairment, and history of alcohol abuse
Physical exam
Central venous pressure
Pulse pressure variation with respiration
Passive leg raising
Respiratory variation in vena cava diameter
ANSWER:
D
Over the last 20 years, there has been a dramatic shift in the
use of intravenous fluid as well as the use of invasive
monitoring systems in the intensive care unit. Both over- and
underuse of intravenous fluids can have detrimental effects.
This situation has led to development of the concept of "fluid
responsiveness." The idea is that before administering more
intravenous fluids to the patient, it would be helpful to know
whether the patient is likely to respond or benefit.
Delirium is associated with increased postoperative
morbidity and mortality. It leads to an increased length of
hospital stay, higher medical costs, and an increased
likelihood of post-discharge institutionalization. In the short
term, patients with delirium after major noncardiac surgery
demonstrate a risk for cognitive decline that is usually
recovered by 2 months. However, in the longer term, patients
who suffer delirium are at a greater risk of cognitive decline
after 3 years than patients without postoperative delirium.
Postoperative delirium is not associated with increased risk
for intensive care unit admission, return to the operating
room, or wound dehiscence.
This patient is developing sepsis and oliguria and has
received 2 L of intravenous fluid. If she is still hypovolemic,
then additional intravenous fluids could be beneficial.
However, if she is hypervolemic and oliguric due to sepsis
and the onset of organ dysfunction, further fluid resuscitation
could adversely affect outcomes. Thus, assessing her volume
status and likelihood of responding to additional fluid
resuscitation is important.
Nonpharmacologic approaches to prevention and treatment
of delirium are increasingly adopted due to their recognized
clinical benefit and cost-effectiveness. They consist of
nursing-based protocols that are implemented daily. These
interventions include reorientation, reduction of psychoactive
medications, early mobilization, promotion of sleep with
sleep protocols, and proper hydration and nutrition. A metaanalysis involving more than 3000 patients showed that
nonpharmacologic interventions tend to reduce overall length
of hospital stay. Pharmacologic approaches to prevent and
treat delirium, meanwhile, have failed to show benefit.
With the decreased use of pulmonary artery catheters,
noninvasive methods of assessing volume status and fluid
responsiveness have become more prevalent. A large metaanalysis of 23 trials involving more than 2200 patients found
that passive leg raising with monitoring of cardiac response
(as done by echocardiography in this case) was the best
method for assessing fluid responsiveness. Both physical
exam and central venous pressure measurement are poor
predictors of fluid responsiveness. Respiratory variations in
both pulse pressure and inferior vena cava diameter were
widely studied. However, the majority of studies for both of
these techniques excluded patients with spontaneous
respiratory efforts, as in this patient (set rate 12, breathing at
22). Additionally, any cardiac arrhythmias can decrease the
accuracy of pulse pressure and cava diameter variation.
24. A 78-year-old nursing home resident with diabetes and
congestive heart failure presented to the hospital 1 week ago
with near-obstructing colon cancer and a 20-pound (10%)
weight loss in the last 2 months. He is now intubated and
ventilated in the intensive care unit after urgent sigmoid
colectomy. Attempted enteral feeding through a nasojejunal
feeding tube resulted in severe abdominal distention. The best
next step to provide nutritional support is
23. A 72-year-old woman is recovering from a partial
gastrectomy. On postoperative day 3, she is agitated and
confused. Postoperative delirium after major abdominal
surgery in older patients is associated with
A.
B.
C.
D.
E.
A.
B.
C.
D.
E.
increased length of hospital stay.
increased intensive care unit admission rates.
a return to operating room.
no change in long-term cognitive performance.
wound dehiscence.
ANSWER:
A
99
trophic gastric feeds (10-20 mL/hour).
parenteral nutrition.
percutaneous endoscopic gastrostomy placement.
peripheral parenteral nutrition.
jejunostomy feeding tube placement.
ANSWER:
E. Cooling to 32°C for 48 hours
B
Timely and adequate nutritional support is an integral part of
the care of the intensive care unit and postoperative patient
Malnutrition is associated with morbidity and mortality in
this patient population, and a catabolic, proinflammatory state
can lead to oxidative stress and multiorgan failure. Thus,
early feeding improves outcomes and likely plays a beneficial
role in immunity. Estimates of caloric needs in the critically
ill patient are weight based and are in the range of 25 to 30
Kcal/kg/day. Protein requirements in the critically ill are
approximately 1.2 g/kg/day.
ANSWER:
Patients admitted to the intensive care unit after out-ofhospital cardiac arrest have a high risk of death and
neurologic deficit. Targeted temperature management (TTM)
is an intervention that has both short- and long-term survival
and neurologic recovery advantages. Guidelines suggest
TTM with urgent coronary angiography as initial steps.
Percutaneous coronary intervention follows if appropriate
lesions are found.
Enteral nutrition is often preferred to parenteral nutrition in
the patient who cannot tolerate per os feeding, because it
maintains gut integrity and modulates the stress and immune
responses. Early initiation of feeds is recommended, even
after gastrointestinal surgery. It is usually started as trophic
feeds (at 10-20 mL/hour) and advanced incrementally to goal
caloric and protein requirements within 24 to 72 hours.
The TTM trial showed that the benefits of 36°C were similar
to a TTM of 33°C. Current recommendations have a target of
33 to 36°C for at least 24 hours.
Common approaches for delivering enteral nutrition to
patients who are unable to maintain sufficient volitional
intake are via nasogastric or nasojejunal feeding tubes,
gastrostomy tubes, and jejunostomy feeding tubes. Enteral
feeding, however, is limited by potential gastrointestinal
intolerance or aspiration. Changing the position of the feeding
tube (gastric vs postpyloric), changing the formula, or
changing the rate of delivery are maneuvers that can improve
gastrointestinal intolerance characterized by abdominal
distention, discomfort, diarrhea, or high residual volume.
The Time-differentiated Therapeutic Hypothermia trial
studied the difference in duration of hypothermia (24 vs 48
hours). This study confirmed no difference in 6-month
neurologic outcomes or mortality in 355 patients randomized
to TTM (33 ± 1OC) for 48 hours or 24 hours. Based on these
results, current recommendations are TTM to 33°C to 36°C
for 24 hours. No recommendation exists to cool to 32°C.
This patient meets Society of Critical Care Medicine and
American Society for Parenteral and Enteral Nutrition
diagnostic criteria for malnutrition (involuntary loss of 10%
or more of usual body weight within 6 months or involuntary
loss of greater than or 5% or more of usual body weight in 1
month). In intensive care unit patients at high nutrition risk,
parenteral nutrition should be started as soon as possible, if
adequate enteral nutrition is not tolerated. Neither peripheral
parenteral nutrition nor trophic feeds will supply this patient
with sufficient calories and protein.
25. A 58-year-old woman underwent an elective laparotomy
for resection of pancreatic cancer with curative
pancreaticoduodenectomy. She was discharged in excellent
condition, but 24 hours later sustained an out-of-hospital
cardiac arrest due to ventricular fibrillation. She was
successfully resuscitated and admitted to the intensive care
unit intubated and ventilated after successful percutaneous
coronary intervention. To improve her chance of survival and
neurologic recovery, what is the recommended use of
targeted temperature management in this patient?
A.
B.
C.
D.
C
Cooling to 32°C for 24 hours
Targeted temperature of 37°C for 24 hours
Cooling to 33° to 36°C for 24 hours
Targeted temperature of 37°C for 48 hours
100
Surgical Critical Care Part II
delirium. Which of the following intravenous infusions for
endotracheal tube tolerance has the lowest risk of delirium?
ITEMS 1-25
For each question, select the best possible response.
A.
B.
C.
D.
E.
1. A 52-year-old patient is critically ill in the intensive care
unit 5 days after urgent hepatic resection for bleeding
hepatocellular cancer. He suddenly develops bright red blood
in one of the surgical drains. Intravascular contrast for CT
angiography is planned as a diagnostic study to consider
angioembolization of the source of bleeding. What strategy is
effective in reducing the risk of contrast associated acute
kidney injury?
A.
B.
C.
D.
E.
ANSWER:
C
Delirium is very common in the intensive care unit and is
frequently related to the sedatives and pain medications used
for endotracheal tube tolerance in intubated and mechanically
ventilated patients. Delirium is associated with adverse
outcomes in intensive care unit patients.
Isotonic saline before and after
Sodium bicarbonate after
Sodium bicarbonate during contrast infusion
Hypertonic saline before and after
Albumin after
ANSWER:
Midazolam
Lorazepam
Dexmedetomidine
Propofol
Ketamine
In 3 meta-analyses including only randomized controlled
trials related to intensive care unit patients, dexmedetomidine
was associated with a reduced incidence of delirium,
intensive care unit length of stay, and mechanical ventilation
duration, despite a significant heterogeneity among studies.
Benzodiazepines, propofol, and ketamine have a higher risk
of intensive care unit delirium. Unfortunately,
dexmedetomidine is associated with an increase in
bradycardia and hypotension.
A
Contrast-induced acute kidney injury (AKI) is reported to be
the third leading cause of AKI in hospitalized patients, with
associated high morbidity and mortality. Current guidelines
recommend intravenous volume expansion with isotonic
crystalloid solution before and after intravascular contrast use
as the cornerstone treatment for the prevention of contrastinduced AKI.
3. A 65-year-old patient underwent elective resection of a
large retroperitoneal] sarcoma. Postoperatively, he developed
severe hypoxemia, and chest radiograph confirmed severe
bibasilar atelectasis. He now requires supplemental oxygen
for treatment of his severe hypoxemia but cannot tolerate
noninvasive positive pressure ventilation via face mask. What
is the best method to provide supplemental oxygen to reduce
the risk of endotracheal intubation?
The HYDRAREA trial tested whether sodium bicarbonate
was superior to isotonic saline in preventing contrastassociated AKI in critically ill patients. Two groups of
critically ill patients with normal renal function (n = 307)
were randomized to intravenous hydration with 0.9% saline
or 1.4% sodium bicarbonate. The same administration
protocol was used with each drug. During the hour before the
contrast the drugs were given at 3 mL/kg and for 6 hours after
the contrast the drugs were given at 1 mL/kg/hour.
Approximately one-third of patients developed contrastassociated AKI in both groups (p = .81). Other similar
outcomes between the 2 groups included need for renal
replacement therapy (5 and 6 patients; p = .77), intensive care
unit length of stay (24.7 ± 22.9 and 23 ± 23.8 days; p =.52),
and mortality (25 and 24 patients; p > .99).
A.
B.
C.
D.
E.
Nonrebreather face mask
Face tent
High-flow nasal cannula
Transtracheal oxygen
Venturi face mask
ANSWER:
Infusions of sodium bicarbonate, hypertonic saline, or
albumin are not recommended for prevention of contrastinduced AKI.
C
High-flow nasal cannula (HFNC) oxygen therapy is
commonly used in intensive care units to provide
supplemental oxygen therapy to patients with hypoxemia and
respiratory insufficiency. HFNC delivers heated humidified
oxygen at a flow rate of 10 to 60 L/minute and more
predictable FiO2 (up to FiO21.0) through nasal prongs. The
delivery of oxygen at high flow rates creates a positive
pressure effect, increases end-expiratory lung volume,
reduces anatomic dead space, and reduces the patients work
of breathing.
2. A 92-year-old patient was admitted to the surgical
intensive care unit after urgent laparotomy for perforated
right colon cancer with fecal peritonitis She is intubated and
mechanically ventilated. Her family reports that the last time
she was in the intensive care unit, she developed severe
102
HFNC was compared with noninvasive positive pressure
ventilation (NIPPV) and conventional oxygen therapy in
adult patients with acute respiratory failure. Eighteen trials
with a total of 3881 patients were pooled in the final analysis.
Compared with conventional oxygen therapy, HFNC was
associated with a lower rate of endotracheal intubation (z 2.55, p - .01) while no significant difference was found in the
comparison with NIPPV (z = 1.40, p = .16). As for intensive
care unit mortality and length of intensive care unit stay,
HFNC did not exhibit an advantage over either conventional
oxygen therapy or NIPPV. NIPPV is more difficult for
patients to tolerate than HFNC or conventional oxygen
therapy, related to the tight-fitting mask required for NIPPV.
The 2016 Surviving Sepsis Guidelines recommend the
following:
... that stress ulcer prophylaxis be given to patients with sepsis
or septic shock who have risk factors for gastrointestinal
bleeding (strong recommendation, low quality of evidence).
Based on the available evidence, the desirable consequences
of stress ulcer prophylaxis outweigh the undesirable
consequences; therefore, we made a strong recommendation
in favor of using stress ulcer prophylaxis in patients with risk
factors.
The American Society of Health-System Pharmacists
(ASHP) Guidelines made similar recommendations.
For patients with acute respiratory failure, HFNC is better
tolerated as a more reliable alternative than NIPPV and
conventional oxygen therapy to reduce the rate of
endotracheal intubation
5.
A 70-year old man underwent an Ivor Lewis
esophagectomy with gastric pull-up 10 days ago His
postoperative course was complicated by an anastomotic leak
•that was managed with a covered stent. He is now
hemodynamically normal but remains deconditioned on the
ventilator. He is afebrile with a normal white btood cell count.
When jejunostomy tube feeds began 4 days ago, he developed
a high output of milky fluid from the right chest tube, which
drained 1200 to 1500 mL per day. Triglycerides in the pleural
fluid measured 400 mg/dl. (<150 mg/dL). Tube feeds were
stopped, and parenteral nutrition was started. After tube feeds
"halted, the chest tube output became serous rather than
milky, but continued to drain more than 1 L per day. His chest
x-ray shows good expansion of the right lung without
effusion. The surgical team is hoping to avoid return to
operating room due to patient's fragile condition. What option
gives the patient best chance to avoid reoperation?
4. Which of the following factors has the highest risk for
clinically important gastrointestinal bleeding from stress
ulcers in critically ill patients?
A.
B.
C.
D.
E.
Mechanical ventilation
Renal failure
Hepatic failure
Shock
Coagulopathy
ANSWER:
A
Stress-related mucosal disease (SRMD) and stress ulcer are
common in intensive care unit patients. The underlying cause
of SRMD is hypoperfusion of the mucosa in the upper
gastrointestinal tract. Hypoperfusion of the mucosa
predisposes an intensive care unit patient to upper
gastrointestinal bleeding. Severed risk factors are associated
with the development of SRMD, and national guidelines
recommend stress ulcer prophylaxis for intensive care unit
patients with these risk factors.
A.
B.
C.
D.
E.
Octreotide
High-dose corticosteroids
Thoracic duct embolization
Talc pleurodesis through chest tube
External beam radiation to thoracic duct
ANSWER:
Two strong independent risk factors (mechanical ventilation
and coagulopathy) for clinically important gastrointestinal
bleeding were identified in a landmark prospective
multicenter study. Clinically important gastrointestinal
bleeding is defined as overt bleeding in association with
hemodynamic compromise or the need for blood transfusion.
Clinically important bleeding occurred in 33 (1.5%) of 2252
patients. Respiratory failure requiring mechanical ventilation
was a stronger risk factor than coagulopathy. Of 847 patients
who had one or both risk factors, 3.7% of patients had
clinically important bleeding (mortality rate 48.5%),
compared with 0.1% in 1405 patients without these risk
factors (mortality rate 9.1%).
C
Thoracic duct leak resulting in chylothorax is a well-known
complication after esophagectomy. It is caused by iatrogenic
injury of the thoracic duct during esophageal dissection.
Chyle appears as milky white drainage from pleural space,
and a triglyceride level greater than 110 mg/dL is diagnostic.
Chyle is also rich in nutrients, lymphocytes, and
immunoglobulins. Consequently, high-volume chyle leaks
result in malnutrition and immunocompromise, with
mortality rates as high as 50%.
If chyle drainage is low (< 0.5 L/day), noninterventional
management with a fat-free diet and somatostatin analogue
usually suffices. Talc pleurodesis via a chest tube is a further
option to treat patients with low-output chylothorax.
103
High-output leaks (>1000 mL/day) generally require ligation
or interruption of the thoracic duct. Thoracic duct ligation
after esophagectomy requires return to the operating room
with either a thoracotomy or thoracoscopy and direct ligation
of the thoracic duct. In deconditioned patients, like the patient
in this question, re-operation is fraught with complications.
failure and severe hypoxemia. ARDS has clinical features
that overlap with other causes of respiratory failure, including
cardiogenic pulmonary edema, viral or diffuse bacterial
pneumonia, and inhalation injury. Four criteria need to be
present to make a diagnosis of ARDS: (1) acute onset of
respiratory symptoms beginning within 1 week of a clinical
insult, (2) bilateral patchy infiltrates on a chest x-ray or chest
CT scan, (3) cardiogenic pulmonary edema or fluid overload
is not the primary cause of the respiratory failure confirmed
with echocardiography, and (4) a PaO2/FiO2 consistent with a
severe impairment of oxygenation. The PaO2/ FiO2 is
calculated by dividing the PaO2 from an arterial blood gas
reading by the FiO2 delivered by the ventilator expressed as
a decimal ranging from 0.21 to 1.0. Reducing positive end
expiratory pressure (PEEP) would worsen his oxygenation.
Thoracic duct embolization (TDE) is a nonsurgical
alternative for treatment of chylothorax. Evidence suggests
that thoracic duct embolization is successful in 60 to 80% of
patients and obviates the need for surgical thoracic duct
ligation. After catheterization, the thoracic duct is occluded
below the point of chyle leakage with embolization coils,
cyanoacrylate glue, or both. The ability to visualize the
lymphatic system and thoracic duct abnormality potentially
increases the treatment success rate, and the minimally
invasive approach eliminates the postoperative morbidity and
mortality
associated
with
reoperation.
Pedal
lymphangiography has been the major technical obstacle for
wider adoption of TDE, and recent development of intranodal
lymphangiography approached via the inguinal lymph nodes
has opened the door for broader application of TDE.
The mainstay of management of ARDS is a lung protective
strategy using low tidal volume ventilation (6-8 mL/kg of
ideal body weight) with high levels of PEEP. Most patients
with mild or moderate ARDS will recover with supportive
care and lung protective ventilation. However, patients with
severe ARDS may have refractory hypoxemia and elevated
plateau pressures despite low tidal volume ventilation.
Several adjunctive therapies have been studied for patients
with severe ARDS, but none are very promising.
For patients with chylothoraces related to malignancy—
usually lymphoma— the pathophysiology of the condition is
decidedly different than thoracic duct injury. The mechanism
by which chyle accumulates in the setting of malignancy
involves infiltration of the thoracic duct and its tributaries
with tumor cells causing obstruction, excess pressure, and
microperforation. Thoracic duct ligation and embolization
are generally ineffective in this setting. Malignant
chylothoraces usually respond favorably to chemotherapy,
and sometimes radiation to posterior mediastinal lymph
nodes; surgical intervention is rarely necessary.
Prone positioning was initially described in case reports and
retrospective series; however, a single large prospective trial
demonstrated a potential benefit. Patients with severe ARDS
ventilated in the prone position had an improvement in
oxygenation allowing a decreased FiO2. There was also a
survived advantage in patients with severe ARDS undergoing
prone ventilation. Because prone ventilation is extremely
labor intensive for staff and requires specialized units, these
results may not be widely applicable. Also, prone ventilation
would not be possible in this patient because both of his
femurs are in traction.
6. A25-year-old man was an unhelmeted rider in a
motorcycle versus tractor trailer crash. He was admitted to the
intensive care unit with a severe traumatic brain injury with
subdural hematoma, a grade III liver injury, and bilateral
femur fractures in traction. On post injury day 1, his oxygen
requirement increases, and he has diffuse, patchy infiltrates
on chest radiograph. He is placed on 6 mL/kg tidal volume
with positive end expiratory pressure (PEEP) of 15 cm H2O
but still |has high plateau pressures. What intervention should
be initiated next?
A.
B.
C.
D.
E.
Corticosteroids may be beneficial for patients with prolonged
courses of ARDS. Patients with refractory ARDS can be
treated with a 30-day course of steroids starting between days
7 and 14. Corticosteroids show an improvement in
oxygenation and ventilator-free days, but mortality data are
mixed. There is a clear detriment to starting steroids after day
14.
Inhaled nitric oxide and inhaled prostaglandins can improve
oxygenation in the first 48 to 72 hours, but there is no survival
benefit.
Neuromuscular blockade
B. Prone position ventilation
C. Reduced level of PEEP to 5 cm H2O
D. Airway pressure release ventilation
Inhaled nitric oxide
ANSWER:
The use of neuromuscular blockade can improve oxygenation
and decrease mortality in severe ARDS. A multicenter trial
of 340 patients randomized patients to neuromuscular
blockade with cisatracurium or placebo within 48 hours of
diagnosis of ARDS. All patients saw an improvement in
oxygenation, and the patients with severe ARDS had a
decrease in 90-day mortality.
A
Acute respiratory distress syndrome (ARDS) is an acute,
diffuse, inflammatory lung injury resulting in respiratory
104
7. Percutaneous tracheostomy
8. An intensive care unit patient undergoes a transthoracic
echocardiogram that shows a pericardial effusion. What
associated feature suggests the strongest need for urgent
pericardial drainage procedure?
A. has a higher complication rate than surgical
tracheostomy.
B. is safe without bronchoscopic guidance.
C. is contraindicated in morbidly obese patients.
D. is safest when performed by surgeons.
E. is contraindicated in patients with recent anterior cervical
spinal surgery.
ANSWER:
A. Echocardiographic evidence of inferior vena cava
collapse
B. 10 mm Hg decrease in systolic blood pressure during
inspiration
C. Effusion loculated behind the left atrium
D. Patient with metastatic effusion
E. Hypotension
B
Percutaneous tracheostomy is a safe and effective alternative
to open tracheostomy. The percutaneous approach tends to
have lower overall costs and can be carried out in an intensive
care unit setting, rather than the operating room, without an
increase in complication rates. The original technique for
percutaneous tracheostomy included the use of a
bronchoscope. Bronchoscopic guidance can visualize
tracheal instrumentation and provide an additional measure
of safety when performing this procedure.
ANSWER:
E
Cardiac tamponade occurs when intrapericardial fluid creates
a situation where the cardiac chambers cannot fill leading to
cardiogenic shock. This situation requires urgent therapeutic
intervention, consisting of either percutaneous pericardial
drainage or surgical pericardial window.
Because the pericardium has limited compliance, even a
moderate volume of pericardial fluid may impair right
ventricular filling, often manifesting with a dramatic drop in
cardiac output, hypotension, and shock. Therefore,
hypotension in the presence of a significant pericardial
effusion demands urgent pericardial drainage procedure to
avoid likely hemodynamic collapse.
There are several techniques for performing bedside
percutaneous tracheostomy without the aid of a
bronchoscope. A modified approach, first described in 1999,
included a small incision with dissection to the pretracheal
space, thus allowing direct visualization of the trachea before
tracheal puncture, serial dilation using the Seidinger
technique, and insertion of the tracheostomy tube. Multiple
large studies showed no difference in complication rates
between procedures performed with and without a
bronchoscope.
Other signs and symptoms of cardiac tamponade are more
subtle, and, although they may help guide the decision to
perform a pericardial drainage procedure, they are not as
specific or urgent as frank hypotension.
Another safe and efficacious technique for tracheostomy
without a bronchoscope is ultrasound-guided tracheostomy.
Ultrasound can be used to visualize the trachea as well as
nearby vascular structures, thus providing additional safety in
lieu of bronchoscopy.
Pulsus paradoxus, defined as a 10 to 20 mm Hg decrease in
systolic blood pressure during inspiration, is often cited as a
sign of cardiac tamponade. Pulsus paradoxus is an
exaggeration of normal diminution in blood pressure during
inspiration rather than a paradoxical situation. Negative
intrapleural pressure causes increased right ventricle filling,
displacement of intraventricular septum to left and thus
decreased left ventricle output. Consequently, stroke volume
and blood pressure are diminished during inspiration.
However, in normal physiologic states, this difference is quite
small. When this difference exceeds 10 mm Hg in the
presence of a pericardial effusion, cardiac tamponade is
considered likely. Nevertheless, many conditions besides
pericardial effusion can cause pulsus paradoxus, including
severe chronic obstructive pulmonary disease, mitral
stenosis, restrictive cardiomyopathy, obesity, and ascites.
Morbid obesity was thought to constitute a relative
contraindication to percutaneous tracheostomy. One recent
study evaluated percutaneous tracheostomy in patients with a
BMI greater than 35 and found no increase in rates of
complication compared with similar patients undergoing
open tracheostomy
Percutaneous tracheostomies are performed by medical
intensivists, rather than surgeons, at many institutions. As
long as the medical intensivists have appropriate training and
credentialing, their results are equivalent to surgeons
performing percutaneous tracheostomy.
Certain findings on echocardiography may indicate the
presence of cardiac tamponade when a pericardial effusion is
present. This list includes early diastolic collapse of the right
ventricle (sensitivity -60%, specificity ~90%) and inferior
vena cava plethora, defined as a diameter greater than 2.1 cm
with less than 50% decrease with inspiration. However, none
of these findings, by themselves, is as important as clinical
A recent study evaluated percutaneous tracheostomy in
patients after anterior cervical spinal surgery and found no
increase in surgical site infection. Percutaneous tracheostomy
is considered safe in this group of patients.
105
hypotension in terms of indicating urgent need for pericardial
drainage.
associated physical exam and lab findings. The fact that the
heart is hyperdynamic with a normal ejection fractions rules
out heart failure and is consistent with diminished afterload,
which is the hemodynamic result of adrenal insufficiency.
Malignant pericardial effusions often develop in patients with
widely metastatic carcinoma. Although malignant pericardial
effusions often require pericardial drainage procedures, the
presence of malignancy is not considered an indication for
urgent drainage.
10. A 78-year-old man is in the surgical intensive care unit 5
days after colectomy for T2 colon adenocarcinoma. He is not
intubated but is on high-flow oxygen. He has a persistent ileus
with nausea and vomiting treated with a nasogastric tube and
parenteral nutrition. He has increased respiratory secretions
requiring frequent suctioning during which he desaturates to
an oxygen saturation of 85%. His respiratory rate is 32
breaths per minute, and he is using accessory muscles to
breath. The next step to manage his respiratory status is
9. A 50-year-old man presents with a traumatic brain injury
and is intubated for airway protection using etomidate and
succinylcholine. Twelve hours later, he is noted to have a
blood pressure of 80/50 mm Hg, heart rate of 122 beats per
minute, temperature of 37°C, and SpO2 of 95%. He remains
hypotensive despite -fluid resuscitation. Laboratory values
include the following: sodium -130 mEq/L (135-145 mEq/L),
potassium - 6.1 mEq/L (3.5-5.0 mEq/L), creatinine - 2.0
mg/dL (0.4-1.30 mg/dL), and glucose = 60 mg/dL (70-100
mg/dL). His initial abdominal CT scan was normal.
Echocardiogram shows a hyperdynamic heart with a normal
ejection fraction. The most likely explanation for his
persistent shock state is
A.
B.
C.
D.
E.
A.
B.
C.
D.
E.
ANSWER:
his head injury.
hyperdynamic heart failure.
missed visceral perforation.
acute kidney failure.
adrenal insufficiency.
ANSWER:
bilevel positive airway pressure.
tracheostomy.
incentive spirometry.
endotracheal intubation.
continuous positive airway pressure.
D
This patient has impending respiratory failure and needs
intubation based on his respiratory parameters and clinical
situation. Avoiding intubation is always a goal of respiratory
therapy, but given this clinical scenario, intubation is
necessary. His respiratory rate, use of accessory muscles,
secretions, and oxygen requirements all indicate the need for
intubation. His clinical condition also supports intubation.
E
Primary adrenal insufficiency or Addison disease results in
symptoms that occur because of title lack of
mineralocorticoid and glucocorticoid made in the adrenal
cortex. The most common cause is autoimmune but there are
a variety of other causes, including drug suppression of
glandular function. The most obvious of these is a patient
whose adrenal function is suppressed by exogenous steroids
taken for any number of diseases. Commonly used drugs
known to suppress adrenal function include ketoconazole and
etomidate.
Continuous positive airway pressure (CPAP) or bilevel
noninvasive positive pressure ventilation (NPPV) can be an
effective and safe intervention for the treatment of adults with
acute respiratory failure after upper abdominal surgery.
However, relative contraindications for these noninvasive
methods of respiratory support include recurrent vomiting,
large amounts of pulmonary secretions, and an inability to
tolerate the devices. The patient's ileus places him at risk for
vomiting and aspiration. His secretions requiring frequent
suctioning would also complicate the use of a noninvasive
form of ventilatory support. A mechanical impediment to the
use of mask ventilation is his nasogastric tube, which will
make secure mask fit difficult.
Common findings include hyponatremia and hyperkalemia.
Hyponatremia is caused by both the loss of sodium in the
urine and the decreased free water clearance associated with
increased vasopressin and angiotensin II. Sodium is lost but
free water remains in the vascular space. Other findings
include unexplained hypotension, abdominal pain, vomiting,
and diarrhea.
Postoperative respiratory failure is best prevented with a
comprehensive program of respiratory support. This program
must include preoperative and postoperative interventions
aimed at improving respiratory function. Components of one
program include preoperative education, incentive
spirometry, mobilization, and proper pain control.
Application of these interventions in isolation has limited
benefit to avoid intubation. Low-quality evidence shows that
CPAP in the postoperative period might reduce postoperative
atelectasis, pneumonia, and reintubation. There is also
insufficient evidence to show high flow nasal cannula
Although a severe head injury could damage the pituitary and
cause secondary adrenal insufficiency due to disruption of the
hypothalamic-pituitary-adrenal axis, this situation is rare and
symptoms are unlikely to occur within 12 hours. A missed
visceral injury, though possible, is minimized by the normal
CT scan and unlikely to cause fluid unresponsive shock so
soon. Acute kidney failure does not explain the vital signs and
106
provides a safe and efficacious respiratory support for adult
intensive care unit patients and can be used to prevent
reintubation routinely.
C. Chlordiazepoxide
D. Clonidine
E. Disulfiram
A tracheostomy is not indicated in this urgent scenario
although might be needed in the future if extubation cannot
be achieved.
ANSWER:
Acute alcohol withdrawal may present in patients with an
alcoholic history undergoing acute surgery and trauma or in
postoperative elective surgery patients where an alcoholic
history is missed. Uncontrolled severe alcohol withdrawal
may include seizures, alcoholic hallucinosis, delirium
tremens, severe hypertension, fluid and electrolyte disorders,
tachyarrhythmias, and death. Protocols for moderate to severe
alcohol withdrawal largely focus on the management of
psychomotor agitation with benzodiazepines. High
intravenous doses of lorazepam are dangerous because the
diluent includes propylene glycol, which can produce lactic
acidosis, myocardial depression, and shock. When high doses
of benzodiazepines are no controlling symptoms and when
excess sympathetic response (hypertension, tachycardia)
occurs, additional agents may be required.
11. Telemedicine in US surgical intensive care units
A.
B.
C.
D.
E.
improves adherence to best-practice guidelines.
is consistently associated with decreases in mortality.
affects 30% of intensive care unit patients nationwide.
decreases resident duty hours.
is prohibited from use across state lines by federal law.
ANSWER:
D
A
Telemedicine in intensive care units is increasing in
frequency but currently affects only 11% of intensive care
unit patients nationally. Telemedicine appears to improve
adherence to best-practice guidelines, but no consistently
demonstrated decrease in intensive care unit mortality is
evident. In a meta-analysis including 35 intensive care units
and 41,734 patients, intensive care unit mortality and length
of stay decreased, but no decrease was seen for in-hospital
mortality or length of stay. A second meta-analysis (11 trials)
showed lower intensive care unit and hospital mortality.
Studies of telemedicine in different hospital settings are
difficult to interpret due to a variety of environments and a
lack of consistency in the elements of telemedicine studied.
This patient is receiving lorazepam at 10 mg/hour, which is a
large dose. Barbiturates and propofol are used in cases of
refractory delirium tremens to induce coma and prevent
seizures. Flumazenil produces rapid benzodiazepine reversal
and may induce seizures. Disulfiram is used in the outpatient
management of alcohol abuse to prevent recidivism, but it is
not used in acute withdrawal. Chlordiazepoxide is used as a
long-acting oral agent in alcohol withdrawal but is not a
preferred agent in the intensive care unit. Alpha-2 agonists,
such as clonidine and dexmedetomidine are not used as
primary agents and may not reduce seizure risk but may be
used adjunctively to reduce benzodiazepine dose,
hypertension, and tachycardia.
Telemedicine in teaching intensive care units has not
decreased resident work hours, but residents have
subjectively reported a positive experience with telemedicine
and its perceived positive impact on patient safety. No federal
laws bar the use of telemedicine across state lines.
Items 13-17
Each lettered response may be selected once, more than once,
or not at all.
12. A 65-year-old man with a history of smoking and
alcoholism is admitted to the intensive care unit after being
found down in the street. A subdural hematoma is diagnosed
and treated nonoperatively by neurosurgery. On hospital day
2, the patient has a Glasgow Coma Scale score of 14 and is
hemodynamically normal. Later that day, the patient develops
acute alcohol withdrawal and is started on lorazepam.
Persistent symptoms require increasingly high doses of
lorazepam, and the patient is intubated for airway protection.
On hospital day 3, the patient is on the ventilator and is
somnolent but opens his eyes with stimulation. He has no
tremors but has a regular heart rate of 130 beats per minute
and a blood pressure of 160/100 mm Hg on a lorazepam drip
of 10 mg per hour. Which medication should be given?
A.
B.
C.
D.
E.
Phenylephrine
Dopamine
Norepinephrine
Epinephrine
Vasopressin
13. Preferred initial pressor for septic shock
14. Available in a premixed bag
15. Can cause reflex bradycardia, especially in spinal cord
injury
16. Primarily used as a second-line agent
17. Acts at 5 different adrenergic receptor subtypes
A. Hydralazine
B. Flumazenil
107
ANSWERS:
dysfunction. The revised adult sepsis guidelines were
published in 2016. The cornerstone of sepsis therapy includes
aggressive fluid resuscitation, prompt initiation of broadspectrum antibiotics, a mean arterial pressure of at least 65
mm Hg, and source control. The new recommendations
specify an initial crystalloid infusion of at least 30 mL/kg
within the first 3 hours. The emphasis on early and aggressive
volume resuscitation is designed to improve patient perfusion
until additional hemodynamic monitoring is put in place.
Albumin can be used as a second-line agent, in addition to
crystalloids, when patients require large volume
resuscitation. The guideline document recommends against
the use of hydroxyethyl starch in sepsis resuscitation, because
it is associated with a higher risk of acute kidney injury and
death.
C, B, A, E, D
The initial choice of vasopressor in critical care patients has
evolved over the past 30 years. Selections are usually
evidence based, but availability, dogma, and habit may play
a role. Before 2000, dopamine was a preferred pressor in
many US intensive care units. However, European trials
showed the relative superiority of norepinephrine over
dopamine in septic shock and discredited "renal dose"
dopamine for acute kidney injury. Because of these findings,
the use of norepinephrine has eclipsed dopamine.
Dopamine's long history may explain its continued
immediate availability in premixed bags in the United States.
Norepinephrine has more alpha-adrenergic mediated
vasoconstriction than dopamine and produces a greater rise in
blood pressure. Dopamine is a stronger inotrope via its larger
beta-adrenergic effects. It produces greater increases in
cardiac output than norepinephrine.
19. Which of the following is an effective rescue strategy in
a patient with severe acute respiratory distress syndrome?
Phenylephrine is a pure alpha-adrenergic vasoconstrictor. It
does not produce the tachyarrhythmias and cardiac irritability
of agents with beta effects but can produce bradycardia when
sympathetic tone is lacking. Phenylephrine is often given via
intravenous push and is the pressor most often used in
peripheral intravenous lines.
A.
B.
C.
D.
E.
Vasopressin has multiple effects, including constriction of
arterioles via the V1A receptor. It is typically used as a secondline agent in septic shock after catecholamine agents, when
response to epinephrine is insufficient in anaphylaxis and
septic shock. It is not superior to norepinephrine in septic
shock.
ANSWER:
18. A 100-kg woman is admitted with cholangitis. After
endoscopic retrograde cholangiopancreatography clears her
common bile duct of obstructing bile duct stones, she is
admitted to the intensive care unit for persistent hypotension
(blood pressure 80/60 mm Hg). The recommended fluid
infusion for the first 3 hours of resuscitation is
Ventilator-induced lung injury is thought to be due to the
shear injury imposed by positive pressure ventilation
resulting from the opening then collapse of alveolar units.
Greater attention is being paid to airway pressures, with
current recommendation of maintaining plateau pressures
less than 30 cm H2O to avoid barotrauma and using normal
(physiologic) tidal volumes, generally 6 mL/kg of predicted
body weight. High-frequency oscillatory ventilation (HFOV)
generated some initial enthusiasm due to the improvements
seen in oxygenation and the relative constant airway
pressures associated with this mode of ventilation.
1000 mL of crystalloid.
2000 mL of crystalloid.
3000 mL of crystalloid.
500 mL 5% albumin.
500 mL of 6% hydroxyethyl starch.
ANSWER:
B
Acute respiratory distress syndrome (ARDS) continues to be
a management challenge in the intensive care unit. No
definitive intervention has been discovered to date to reverse
or prevent the development of ARDS, and treatment is
generally supportive. This supports the observation that
ARDS is a heterogenous process with multiple etiologies that
include intrinsic respiratory injury and exogenous pulmonary
factors such as injury from cytokine release due to the
systemic inflammatory response syndrome. Only modest
improvements in survival have occurred in the past several
decades, largely due to strategies designed to protect the lung
from ventilator-induced lung injury. Controversy remains
over the most effective ventilation strategies: high-versus low
positive end-expiratory pressure (PEEP), permissive
hypercapnia, open-lung ventilation strategies, FiO2-PEEP
tables, a resurgence of the "best-PEEP" concept, recruitment
maneuvers, and the like.
Epinephrine acts at all 5 adrenergic receptors. It is the only
listed agent that combines vasoconstriction, vasodilation,
inotropy, chronotropy, bronchodilation, glycogenolysis, and
lipolysis.
A.
B.
C.
D.
E.
Plat, greater than 35 cm H2O
Prone positioning
Positive end-expiratory pressure of 5 cm H2O or less
High-frequency oscillatory ventilation
Tidal volume of 8 to 10 mL/kg
C
Sepsis is a life-threatening condition that must be treated
immediately to reverse hypotension and mitigate organ
108
Subsequent studies have not demonstrated any mortality
benefit for HFOV, and adequate oxygenation can be achieved
with current airway-protective ventilation strategies that do
not require expensive ventilators and expertise.
Traditional tidal volumes of 10 to 15 mL/kg exceed normal
tidal volumes in a resting adult and run the risk of
overdistending open alveolar segments and exacerbating
abnormal ventilation perfusion relationships (i.e., increasing
physiologic shunt and producing shear stress/injury). A
clinical trial comparing traditional tidal volume settings with
low tidal volumes of approximately 6 mL/kg of ideal body
weight demonstrated decreased mortality and increased the
number of ventilator-free days in patients with acute lung
injury and acute respiratory distress syndrome. An
appropriate initial ventilator setting is 6 mL/kg x 70 kg = 420
mL tidal volume, with the addition of positive end-expiratory
pressure (PEEP) obtained from a PEEP/FiO2 table or titrated
to keep the peak plateau airway pressure less than 30 cm
H2O. Minute ventilation, and consequently arterial pH, is
maintained by adjusting the rate of ventilation. The goal for
oxygen saturation is 85 to 95%.
It has been known for some time that placing mechanically
ventilated patients in the prone position improves
oxygenation. The effect is thought to be due to improvements
in functional residual volume because of improvements in
dorsal lung ventilation, a reduction in ventilation/perfusion
mismatching (physiologic shunt), an improvement in lung
recruitment, a reduction in ventilator-induced lung injury by
a more homogeneous distribution airway pressure among
alveolar units, and a decrease in circulating inflammatory
cytokines. Prone positioning redistributes airway pressure
over a larger alveolar surface area, which minimizes shear
injury, particularly when PEEP is concomitantly used.
Additionally, prone positioning generally allows higher
levels of PEEP, which may help prevent derecruitment of
alveoli. Recent clinical studies and several large metaanalyses demonstrated not only improvement in oxygenation
but also better survival. Prone positioning is well tolerated but
somewhat resource intensive because it requires trained staff
familiar with the techniques. To be effective, patients should
be kept prone for more than 12 hours per day. Prone
positioning is now included in the practice guidelines for
moderate to severe ARDS by the American Thoracic Society,
the European Society of Intensive Care Medicine, and the
Society of Critical Care Medicine.
Items 21-23
Each lettered response may be selected once, more than once,
or not at all.
A.
B.
C.
D.
E.
Amiodarone
Calcium-channel blocker
Cardioversion
Intravenous magnesium
Atropine
21. Monomorphic ventricular tachycardia with hypotension
22. Monomorphic ventricular ectopy
20. A 42-year-old man fell from a height of 40 feet at a
construction site. His injuries include multiple left-sided rib
fractures with a flail segment of his chest wall, a left-sided
pulmonary contusion, and a pelvic fracture. He is
appropriately resuscitated but requires intubation for
respiratory distress with severe hypoxemia. His weight is 78
kg (ideal body weight - 70 kg). The most appropriate initial
tidal volume setting is
A.
B.
C.
D.
E.
23. Bradycardia with hypotension
ANSWERS:
In monomorphic ventricular tachycardia, the electrical
conduction is prolonged when moving across the ventricles.
This results in a widened QRS complex. When all of the
complexes appear the same, the phenomena is called
monomorphic. The pathophysiology behind this electrical
activity is a result of the same ventricular focus initiating the
conduction, and, hence, the contraction, within the ventricle.
Immediate cardioversion is the appropriate treatment when
monomorphic ventricular tachycardia occurs with
hypotension.
200mL.
420mL.
600mL.
780mL.
1170mL.
ANSWER:
C, E, A
B
Monomorphic ventricular ectopy is characterized by the
appearance of premature ventricular contractions (PVCs) that
have the same morphology and are, therefore, called
monomorphic. Single PVCs are not concerning. Couplets (2
sequential PVCs) are more concerning. Monomorphic
ventricular ectopy often does not need to be treated. When
required, the treatment of choice is amiodarone.
The goals of mechanical ventilation in the case presented are
(1) to assist the patient in obtaining the necessary oxygenation
and oxygen delivery, (2) to maintain the maximum alveolar
surface area and possibly recruit atelectatic alveoli, (3) to
minimize the risk of ventilator-induced lung injury, and (4) to
allow the patient to provide the work of breathing appropriate
under the clinical circumstances to maintain respiratory
muscle tone and conditioning.
Narrow complex tachycardia is caused by an electrical
impulse being initiated above the atrioventricular node and
109
the impulse traveling down the Purkinje fibers. The treatment
of this arrhythmia is to block the AV node with a calcium
channel blocker medication.
C. Complicated sepsis
D. Severe sepsis
E. Septic shock
Torsade de pointe is most commonly precipitated with a drug
that prolongs the Q-T interval, such as methadone,
haloperidol, and levofloxacin. Treatment is targeted at
removing the offending agent and administering magnesium.
ANSWER:
Sepsis is a complex infection syndrome marked by aberrant
host response and organ dysfunction. Sepsis is highly
prevalent and accounts for approximately 5% of total US
hospital costs. The European Society of Intensive Care
Medicine and the Society
Bradycardia is treated with atropine, an acetylcholine
receptor antagonist that blocks the parasympathetic activity.
24. Regarding the use of a 1:1:1 massive transfusion protocol
(MTP), which of the following statements is true?
of Critical Care Medicine recently revised their consensus
definitions and criteria to identify patients with sepsis. The
new operational definitions emphasize organ dysfunction as
a part of sepsis. The systemic inflammatory response
syndrome is not specific to infection and may be adaptive in
hospitalized patients. Sepsis is now defined as a sequential
organ failure assessment (SOFA) score of at least 2 in the
setting of suspected of infection. The quick SOFA (qSOFA)
score is simpler to use and can be used at the bedside instead.
qSOFA assigns 1 point each for altered mentation, respiratory
rate of at least 22/min, and systolic blood pressure of 100 mm
Hg or less (table 25.1). Septic shock is identified in patients
with persistent hypotension requiring a pressor to maintain
mean arterial pressure of at least 65 mm Hg and having a
serum lactate level of at least 2 mmol/L (0.5-1 mmol/L),
despite adequate volume resuscitation. With the new
definitions, the terms severe and complicated sepsis are no
longer needed.
A. MTP increases the overall use of blood products.
B. MTP decreases 30-day mortality.
C. A transfusion plan of 1:1:1 means 6 units of packed red
blood cells: a 6 pack of platelets:6 units fresh frozen
plasma.
D. Since the implementation of MTP triggers, MTPs are
used more frequently.
E. A hemoglobin of 10 g/dL is one of the transfusion goals.
ANSWER:
B
C
Using early balanced resuscitation for trauma patients
provides documented benefits.
Early balanced resuscitation means giving equal amounts of
platelets, packed red blood cells, and fresh frozen plasma to
trauma patients who require transfusion. This means a ratio
of 1:1:1, which means one 6 pack of platelets for every 6 units
of packed red blood cells and 6 units of fresh frozen plasma.
In prospective trials, multicenter trials, and meta-analyses,
the ratio shows improved 24-hour survival and decreased
death from exsanguination and truncal hemorrhage. Critics
have countered that 30-day survival is not improved. The use
of early balanced resuscitation does not increase the overall
use of blood products or the implementation of a massive
transfusion protocol. In other words, it does not
waste more blood products. Massive
qSOFA (Quick SOFA) Criteria
Points
Respiratory rate ≥ 22 breaths/minute
1
Change in mental status
1
Systolic blood pressure ≤ 100 mm Hg
1
Table 25.1. Quick sequential organ failure assessment
(SOFA) score.
transfusion protocol protocols do not aim for a
specific hemoglobin goal.
25.
A 50-year-old man presents with complicated
diverticulitis. He undergoes percutaneous drainage of a pelvic
abscess. His vital signs include a temperature of 38°C, blood
pressure of 90/55 mm Hg, mean arterial pressure of 65 mm
Hg, and respiratory rate of 24 breaths per minute. On exam,
he is diaphoretic, confused, and does not follow commands.
What is the most appropriate intensive care unit diagnosis?
A. Systemic inflammatory response syndrome
B. Sepsis
110
Trauma Part I
A grade V injury involves massive disruption of the
duodenopancreatic complex or duodenal devascularization.
In a retrospective review at one institution, children with
grade II, III, and IV injuries were successfully managed with
primary repair, and children with grade II, III and IV injuries
repaired primarily did as well as or better than children with
similar injuries managed by pyloric exclusion or
gastrojejunostomy.
ITEMS 1-28
For each question, select the best possible response.
1. A 7-year old girl is admitted after she was a restrained
passenger in a T-bone motor vehicle crash with impact on her
side of the car. She is tachycardic and has an acute abdomen.
At surgery, she has an isolated duodenal perforation in the
second portion opposite the ampulla of Vater involving 25%
of the circumference. What is the best operative plan?
Duodenal diverticulization refers to suture closure of the
duodenal
injury,
antrectomy
with
end-to-side
gastrojejunostomy, and tube duodenostomy. It is a complex,
time-consuming procedure that is generally unnecessary. The
triple tube technique of drainage is unnecessary in a grade II
injury.
A. Primary repair of the duodenum
B. Pyloric exclusion
C. Repair the duodenum, gastrostomy, jejunostomy, and
duodenostomy
D. Duodenal diverticularization
E. Gastrojejunostomy, nasogastric decompression, nasojejunal feeding tube
ANSWER:
2. A 22-year-old man is involved in a motorcycle crash. His
injuries include a left pulmonary contusion, a comminuted
open left femur fracture, and a mild closed head injury
(Glasgow Coma Scale score = 12). He was placed in skeletal
traction, started on antibiotics, and provided supplemental
oxygen by nasal cannula while awaiting open reduction and
internal fixation of his femur fracture. At 36-hours postinjury,
his confusion has increased, his pulse oximeter indicates 88%
saturation, and he has developed the skin lesions shown
(figure 2.1). The most likely cause for these findings is
A
Blunt injuries to the duodenum are uncommon in all ages.
They account for approximately 3 to 5% of all intraabdominal injuries. Blowout injuries after blunt trauma can
occur due to the retroperitoneal fixed nature of the duodenum
and compression against the vertebral column. Five grades of
duodenal injury were described in 1990 using a standardized
organ injury scale (table 1).
Grade*
Type of
Injury
Description
I
Hematoma
Involving single portion of the duodenum
Laceration
Partial thickness—no perforation
Hematoma
Involving more than one portion of the
duodenum
Disruption by <50% of circumference
II
Laceration
III
Laceration
IV
Laceration
V
Laceration
Vascular
A.
B.
C.
D.
E.
a drug reaction.
fat embolism syndrome.
drug-induced thrombocytopenia.
sequela from pulmonary contusion.
progression of his traumatic brain injury.
Disruption by 50-75% of circumference of
D2
Disruption by 75-100% of circumference of
D1/D3/D4
Disruption by >75% of circumference
Involving ampulla or distal common bile
duct
Massive destruction of duodenopancreatic
complex
Devascularization of duodenum
*Advance one grade for multiple injuries up to grade III. D1,
first portion of duodenum; D2, second portion of duodenum;
D3, third portion of duodenum; D4, fourth portion of
duodenum.
Table 1.1 Duodenal Injury Scale (AAST-OIS).
Figure 2.1.
A grade I injury is a hematoma or laceration without
perforation; a grade II laceration equates to a disruption of
less than 50% of the duodenal circumference; grade III 50 to
75% circumference of D2 or 50 to 100% of D1, D3, or D4;
and grade IV disruption more than 75% circumference of D2
involving the ampulla or distal common duct.
ANSWER:
B
Fat embolism syndrome (FES) was described more than 150
years ago by Zenker, but the precise etiology remains elusive.
Classic features of FES include young adults (10-40 years of
age), associated long-bone or pelvic fractures, male sex,
112
concomitant pulmonary injury, and delayed fracture
stabilization. FES is also reported after spinal surgery,
vertebroplasty, and intramedullary fixation. The reported
incidence varies between 0.2% and 35%, depending on the
series. The clinical features are nonspecific and generally
indistinguishable from acute respiratory distress syndrome
(ARDS). These include hypoxia, respiratory distress (varying
from mild to severe enough to warrant mechanical ventilatory
support), mental status changes, fever, tachycardia,
tachypnea, retinal splinter hemorrhages, oliguria/anuria, and
occasionally jaundice. One of the classic, but inconsistent,
findings in FES is a petechial rash over the anterior thorax
and axilla. The rash may be transient, lasting only 24-hours
or less (figure 2.1). This rash differentiates FES from adverse
drug reactions, which tend to be more generalized. Druginduced thrombocytopenia does not characteristically
produce a skin rash (although thrombocytopenia is reported
in association with FES), nor does progression of a
pulmonary or traumatic brain injury
30-second loss of consciousness. He has a patent airway
without difficulty breathing, and his vital signs are normal.
He opens his eyes to speech and obeys commands, but he is
confused and perseverating. No other injuries are noted on
secondary survey. What is the most appropriate next step in
his management?
A.
B.
C.
D.
E.
Discharge home with instructions
Observation with re-evaluation in 4 hours
CT scan of the head
Admission overnight
Neurosurgical consultation
ANSWER:
B
Approximately 1.7 million Americans present to the
emergency department annually after sustaining a traumatic
brain injury (TBI). Of this number, approximately 80% are
treated and released without the need for hospitalization.
Among adults, falls and motor vehicle crashes are the most
common causes for TBI. In the 15- to 24-year-old age group,
however, sports-related injuries are second only to motor
vehicle crashes as the causative etiology.
Two theories are proposed to explain the pathophysiology.
The mechanical theory proposes that fat globules forced into
the systemic circulation from bone marrow obstruct
pulmonary capillaries, resulting in an increased shunt and
hypoxia. The same mechanism is also operative in the brain
and kidney, explaining the changes in mental status and renal
dysfunction. Evidence to support this hypothesis comes from
the identification of fat globules observed in serum, sputum,
and urine and seen on duplex scans and transesophageal
echocardiography. Cutaneous capillary obstruction produces
the skin rash. The biochemical hypothesis suggests that fat
globules are broken down to free fatty acids by lipases, which
trigger activation of the inflammatory cascade. This results in
pulmonary alveoli and endothelial injury, identical to that
seen in ARDS. Inflammatory activation also affects other
organs, explaining the central nervous system, renal, and
hepatic dysfunction. Evidence to support this hypothesis is
based on serum elevations of inflammatory mediators. It is
likely that both hypotheses may be operative.
Closed head injuries are the most common form of TBI, and
the resultant neurologic damage arises from primary and
secondary processes. Primary injury occurs from the direct
transmission of force to the neurons and their long axons,
creating shear forces from differences in acceleration along
their paths. Secondary injury results from the subsequent
sequelae of the force transmission: hypoxia; hypotension;
hydrocephalus; and intracranial hypertension, thrombosis, or
hemorrhage. Concussions, contusions, and diffuse axonal
injury are all examples of closed head injuries.
For TBIs, the Glasgow Coma Scale (GCS) provides a method
of stratifying severity. Determining GCS score is an integral
part of the primary survey for Advanced Trauma Life Support
(ATLS), assessed during the disability (i.e., D) phase. It
assigns points to 3 neurologic responses: motor, verbal, and
eye-opening (table 3.1). The cumulative score determines
TBI severity: mild (13-15 points), moderate (9-12 points),
and severe (3-8 points).
Treatment is supportive, and FES is usually self-limited.
Severe cases may require ventilator support. Mortality from
FES by itself is quite low due to advances in critical care and
ventilatory support (<5% compared with the >30% reported
several decades ago), and death is usually attributable to other
associated injuries. Patients with central nervous system
manifestations of FES do not appear to have a worse
prognosis.
Mild severity closed head injuries are concussions that are
defined by the American Academy of Neurology as a
"trauma-induced alteration in mental status that may or may
not result in loss of consciousness." They can be graded based
on the degree of mental status change: grade 1 = confusion
only; grade 2 = associated amnesia; grade 3 = associated loss
of consciousness.
Early fracture stabilization is generally accepted as the most
effective means of prevention. Pharmacotherapy to prevent
and treat FES is disappointing, but some limited data show
that prophylactic steroids may reduce FES and hypoxia, but
not mortality.
Approximately 3.8 million sports-related concussions occur
annually in the United States. For patients presenting to the
emergency department, the workup and treatment algorithm
consider the degree of initial injury as well as neurological
status over time. Patients presenting with grade 1
concussions, grade 2 concussions with perievent amnesia,
3. A 17-year-old high school football player is brought to the
emergency department after a head-to-head collision with a
113
and grade 3 concussions with less than 1-minute loss of
consciousness may be observed in the emergency department
for several hours. If patients' neurologic exam remains
normal without worrisome symptoms after this period, they
may be discharged home with comprehensive instructions
and a reliable individual to observe them for the first day after
the injury. All other patients sustaining grade 2 or 3
concussions, as well as those patients with progressive
headache, vomiting, skull/facial fractures, seizure, abnormal
neurologic exam, deteriorating neurologic status,
alcohol/drug
intoxication,
coagulopathy
(including
anticoagulant therapy), and age older than 60 should have CT
imaging to rule out intracranial injury. If the CT scan is
normal and the neurologic status returns to baseline (save
amnesia of the event) after observation, the patient may be
discharged home under the care of a responsible individual.
Otherwise, 24-hour observation in the hospital is indicated.
MOTOR RESPONSE
VERBAL RESPONSE
EYE-OPENING RESPONSE
Obeys commands
6
Oriented
5
Opens spontaneously
4
Localizes to pain
5
Confused
4
Opens to speech
3
Withdraws from pain
4
Inappropriate words
3
Opens to pain
2
Flexor posturing
3
Unintelligible sounds
2
No eye opening
1
Extensor posturing
2
No sounds
1
No movement
1
"Add the 3 scores to obtain the Glasgow Coma Scale (GCS) score, which can range from 3 to 15. Add “T” after the
GCS if intubated and no verbal score is possible. For these patients, the GCS can range from 3T to 10T.
Table 3.1 The Glasgow Coma Scale score.
4. A 26-year-old man presents to the trauma bay after his left
thigh was crushed between a wall and car. At the scene, he
was bleeding copiously from a puncture wound in his thigh.
He has a patent airway, is breathing normally, and is
normotensive but tachycardic. His left thigh is visibly
deformed with a nonbleeding puncture wound with visible
bone. A pulsatile hematoma is medial to the puncture wound.
He cannot dorsiflex his foot, and he has a diminished dorsalis
pedis pulse. Of the findings in the trauma bay, which
mandates exploration to evaluate and potentially treat a
vascular injury?
A.
B.
C.
D.
E.
A key component of the management of extremity trauma is
determining whether a coexistent vascular injury requiring
operative repair is present. In certain situations, signs on
examination indicate the definite presence of a vascular
injury, mandating immediate exploration of the area of injury
in the operating room. Such hard signs indude active
hemorrhage from the injury, absent pulse distal to the injury,
the presence of a bruit or thrill near the site of injury, and an
expanding or pulsatile hematoma associated with the injury.
In other situations, the signs on examination are more subtle
("soft signs"), warranting further diagnostic workup and
imaging, but do not mandate operative exploration. These
soft signs include a large amount of reported blood loss at the
scene of the injury, severe orthopedic injuries, concomitant
nerve injury, subjective decrease in pulse distal to the injury,
and presence of a large nonpulsatile hematoma associated
with the injury. This patient has a hard sign of a vascular
injury (a pulsatile hematoma) that mandates operative
exploration.
Copious blood loss at scene
Compound femur fracture
Pulsatile hematoma
Neurologic deficit
Diminished pulse
ANSWER:
C
114
5. A 17-year-old is involved in a high-mechanism motor
vehicle collision, sustaining a grade IV liver injury. Trace
pneumomediastinum located anterior to the esophagus is
noted on CT scan (figure 5.1). The presence of
pneumomediastinum after blunt trauma
C. resuscitative endovascular balloon placement.
D. placement of a left tube thoracostomy.
E. 1 mg of epinephrine.
A.
B.
C.
D.
E.
ANSWER:
requires further evaluation with triple endoscopy.
signifies an esophageal injury in 10% of cases.
is identified in 20% of blunt trauma patients.
is often a benign finding.
correlates with the extent of an associated pneumothorax.
Witnessed traumatic arrest should prompt the surgeon to
perform a resuscitative left anterolateral thoracotomy.
Thoracotomy permits evaluation and treatment of
intrathoracic injuries, which in this case is likely to be cardiac
tamponade from a penetrating cardiac injury. The
pericardium is incised from the apex toward the great vessels,
anterior to the left phrenic nerve. The heart is then delivered
through this anterior opening in the pericardium and the
cardiac injury delineated. If the patient has intrinsic cardiac
activity, digital occlusion of the injury followed by repair in
the operating room is performed. If the heart is asystolic, the
cardiac injury is repaired and then injection of epinephrine
and defibrillation is performed. During pericardotomy, the
right hemithorax may be decompressed by making an
aperture through the pericardium. This action will relieve a
right-sided tension pneumothorax if present in this patient
with right-sided penetrating trauma.
Figure 5.1.
ANSWER:
B
Although focused assessment with sonography for trauma
(FAST) exam of the pericardium may reveal
hemopericardium, this is evident only if the patient's heart is
beating. Without intrinsic cardiac activity, it may be difficult
to identify the fluid stripe around the heart distinct from the
cardiac chambers. Delaying intervention to perform a FAST
exam is not warranted.
D
Pneumomediastinum is identified in only 2 to 10% of blunt
trauma patients and is often a benign finding. In a recent
study,
only
1%
of
patients
with
identified
pneumomediastinum had an esophageal injury. In most cases,
patients have associated chest trauma, most commonly a
pneumothorax; pneumomediastinum in these cases is caused
by air dissecting along the pulmonary vasculature from
injured alveoli, termed the Macklin effect. There does not
appear to be a correlation between the extent on an associated
pneumothorax and the volume of a pneumomediastinum. CT
scan can be used as a screening tool. The identification of air
located in the posterior mediastinum or throughout all
mediastinal compartments (anterior, superior, and posterior)
is the most concerning finding and should prompt additional
contrasted imaging/endoscopy to rule out an esophageal
injury.
Resuscitative endovascular balloon occlusion of the aorta
(REBOA) placement is being used in some centers for
patients with blunt traumatic arrest; however, REBOA will
neither diagnose nor treat cardiac tamponade. In addition to
performing the left thoracotomy, a concurrently placed right
tube thoracostomy will decompress any associated tension
pneumothorax or hemothorax. A left tube thoracostomy is not
needed in a patient better suited to a thoracotomy.
7. A 26-year-old man sustains a stab wound to the abdomen.
On abdominal exploration, an injury to the second portion of
the duodenum with 25% loss of the lateral wall is discovered.
What is the most appropriate next step?
A.
B.
C.
D.
E.
6. A patient presents with a 4-cm stab wound to the chest
located 2 cm to the right of the sternum. During transport, his
blood pressure is 100/55 mm Hg, his heart rate is 100
beats/minute, and his respiratory rate is 28 breaths/minute.
On arrival to the emergency department, he loses pulses. The
most appropriate next step in this patient's management is
A. focused assessment with sonography for trauma of the
pericardium.
B. left anterolateral thoracotomy.
115
Lateral tube duodenostomy
Primary repair of the duodenum
Duodenal resection and primary anastomosis
Duodenojejunostomy
Pyloric exclusion and gastrojejunostomy
ANSWER:
if the injury can be fully evaluated and closed. Historically,
presacral drain placement and distal rectal washout was
performed for all patients with extraperitoneal rectal injuries.
These measures, which involve dissection of normal tissue
planes and liquefication of the stool burden, increase
morbidity and hence are not routinely advocated.
B
Most duodenal injuries can be primarily repaired. This is a
grade II injury, with disruption of less than 50% of the
circumference of the wall (table 1.1). Primary repair after
debriding any devitalized tissue (commonly needed for
gunshot injuries but less common for stab wounds) should be
performed. Removing the uninjured wall with resection and
primary anastomosis is not needed. More complex
reconstructions, such as a duodenojejunostomy or resection
with duodenoduodenostomy, are necessary only for grade HI
injuries (disruption of 50-75% of D2 and 50-100% of D1, D3,
or D4) or higher injuries. Destructive injuries to the
duodenopancreatic
complex
often
require
pancreaticoduodenectomy.
9. A 26-year-old man is involved in a motorcycle collision.
On imaging, a pelvic fracture and bladder injury are identified
(figure 9.1). What is the most appropriate next step to manage
his bladder injury?
A.
B.
C.
D.
E.
Lateral tube duodenostomy may be helpful in patients who
leak after a duodenal repair breaks down but should not be
used at the initial surgery. Pyloric exclusion with associated
gastrojejunostomy is typically used in patients requiring
duodenal repairs who also have an associated pancreatic
injury. In these situations, the associated pancreatic injury
may cause breakdown of the duodenal repair (the sutures may
dissolve from the pancreatic fluid). The diversion of the
gastric contents permits adequate drainage of the area without
development of a lateral duodenal fistula that is unlikely to
heal.
8. A 31-year-old man presents after a gunshot wound to the
right buttock. Exam under anesthesia identifies blood in the
rectum at 8 to 10 cm from the dentate line concerning for an
extraperitoneal rectal injury. In addition to confirming, an
extraperitoneal rectal injury, what is the most appropriate
next step in this patient's management?
A.
B.
C.
D.
E.
Figure 9.1.
ANSWER:
D
This patient has an intraperitoneal bladder injury (figure 9.2)
that should be managed with operative repair, performed via
either an open or laparoscopic approach.
Direct repair
Direct repair with proximal diversion
Proximal diversion
Proximal diversion and presacral drain placement
Proximal diversion, presacral drain placement, and distal
rectal washout
ANSWER:
Suprapubic tube placement
Cystoscopy
Foley catheter treatment for 2 weeks
Operative repair
Retrograde urethrogram
C
This extraperitoneal rectal injury is located quite high, hence
making primary repair challenging, if not impossible. In such
cases, proximal diversion with a loop colostomy is the safest
management option. After proctoscopy, diversion can be
accomplished with either a laparoscopic or open approach
based on the patients prior surgical history and current
physiology. A loop colostomy effectively diverts the fecal
stream, allowing the injury to heal, while optimizing
operative reversal for this temporary stoma (compared with
using an end-colostomy/Hartmann, which is more difficult to
reverse). If an extraperitoneal rectal injury is located much
closer to the anal opening, primary repair may be considered
Figure 9.2. Extravasation of contrast in an intraperitoneal
location
Laparoscopic repairs, particularly in patients without other
intra-abdominal injuries, are advocated. Suprapubic tubes are
typically placed for patients with urethral injuries in whom a
Foley catheter cannot be passed. Cystoscopy is not indicated
because the diagnosis is already confirmed on CT imaging.
Extraperitoneal bladder injuries are managed with catheter
drainage alone (typically Foley, rarely suprapubic tube), and
116
more than 85% will heal within 14 days. A retrograde
urethrogram is used to diagnose a urethral injury; it is not
indicated at this time because a Foley catheter has already
been successfully placed for the CT cystogram.
A.
B.
C.
D.
E.
10. A 25-year-old man sustains a left zone II neck stab
wound. He is hemodynamically normal without hard signs of
an aerodigestive or vascular injury. He has dysphagia. What
is the most appropriate next step in management?
A.
B.
C.
D.
E.
ANSWER:
A
Patients with a traumatic brain injury and intracranial
hemorrhage are at high risk of developing a venous
thromboembolism (VTE; up to 25%). A traumatic brain
injury is an independent risk factor for VTE. This risk is
amplified by mechanical ventilation and other associated
injuries. Chemical prophylaxis decreases the incidence of
VTE in multiply injured patients, and guidelines recommend
the use of low molecular weight heparin (LMWH) over
unfractionated heparin (UFH). Concern was raised about
worsening of intracranial hemorrhage with the use of
chemical prophylaxis, but several retrospective studies and
systematic reviews have demonstrated its safety. Early
chemical prophylaxis, within 24 to 48 hours after injury, did
not increase the rate of hemorrhage progression.
CT scan of the neck
Esophagram
Flexible esophagoscopy
Angiography
Neck exploration
ANSWER:
Low molecular weight heparin
Aspirin 81 mg
Unfractionated heparin
Screening duplex imaging
Retrievable inferior vena cava filter
A
The management of zone II penetrating neck injuries has
evolved from mandatory neck exploration for all injuries to
selective management of most injuries. CT angiogram (CTA)
of the neck has emerged as the diagnostic study of choice in
patients who have sustained penetrating trauma to the neck
who require further workup to evaluate potential injuries.
CTA is rapid to obtain, noninvasive, and an excellent
screening tool for penetrating neck wounds.
Current recommendations are for sequential compression
devices for the initial 24 to 48 hours after presentation,
followed by chemical prophylaxis. LMWH and UFH have
not been directly compared in this patient group, but both
drugs have been studied. Either drug is acceptable for
chemical prophylaxis.
CTA of the neck is not sensitive enough to completely rule
out esophageal injury; however, it is preferred as the initial
diagnostic study because it has the ability to further evaluate
the potential for tracheal, esophageal, and vascular injury.
When the CTA of the neck is suggestive of esophageal injury,
the patient requires additional testing, especially in the setting
of dysphagia or odynophagia. Further workup should include
contrast esophagram or flexible esophagoscopy. The
combination of both procedures yields a nearly 100%
sensitivity for diagnosing esophageal injuries. Water-soluble
contrast (Gastrografin) is used first with contrast
esophagraphy. If this is not diagnostic, Gastrografin is
followed by thin barium.
Mechanical prophylaxis with sequential compression devices
(intermittent pneumatic compression) can be used in patients
with contraindications for chemical prophylaxis. Compared
with no prophylaxis, mechanical devices decrease the rate of
VTE. However, chemical prophylaxis provides superior VTE
prevention over sequential compression devices or
intermittent pneumatic compression. Aspirin is used in
orthopedic patients as a single agent but is currently not
recommended for nonorthopedic surgery patients.
Retrievable inferior vena cava filters are an attractive
nonpharmacologic method to decrease VTE risk. In several
nonrandomized trials, the short-term pulmonary embolus rate
was decreased but the deep vein thrombosis rate was
increased. Insertion complications, inferior vena cava
occlusions, and filter migrations were also reported. Given
these complications, inferior vena cava filter placement is not
recommended over chemical prophylaxis.
Neck exploration may be indicated if an injury requires
surgery; however, it is not the initial step in management of
this patient. This is because the patient does not have signs of
injury mandating operative intervention.
11. A 30-year-old unhelmeted man was involved in a
motorcycle crash. His initial Glasgow Coma Scale (GCS)
score was 13. A CT scan of his head showed a parietal skull
fracture and 3-mm subdural hematoma. He was admitted to
the intensive care unit for observation. Repeat head CT scan
the next day shows no change in the subdural hematoma, and
his GCS is now 15. In addition to sequential compression
devices, what is the best way to decrease his risk of venous
thromboembolism?
A surveillance protocol with venous compression
ultrasonography was used in trauma patients with
contraindications for chemical or mechanical prophylaxis.
However, the rate of pulmonary embolism was unchanged,
and false positives were reported. Routine surveillance
venous compression ultrasonography is not recommended as
a method of primary prophylaxis.
117
12. A 45-year-old man is the restrained driver involved in a
2-vehicle, high-impact motor vehicle collision. He presents to
the trauma bay hemodynamically normal with an abdominal
wall seatbelt sign. CT scan of the abdomen shows a contained
retrohepatic vena cava injury as the only abnormality. The
patient remains hemodynamically normal. Labs obtained
return a hemoglobin of 13 g/dL (13.5-17 5 g/dL) and show
the patient is not acidotic. What is the most appropriate next
step in management?
A.
B.
C.
D.
E.
A.
B.
C.
D.
E.
observation.
angioembolization.
splenorrhaphy.
splenectomy.
distal pancreatectomy and splenectomy.
Admission with observation
Damage-control laparotomy with perihepatic packing
Primary repair of the injury
Endovascular stent
Atriocaval shunt
ANSWER:
A
Retrohepatic vena caval injuries are some of the most feared
injuries treated by even the most seasoned trauma surgeons.
Because the retrohepatic vena cava is surrounded by
suspensory ligaments of the liver and the diaphragm,
operative mobilization of these structures can result in
torrential hemorrhage and death. A surgeon may also feel
compelled to surgically repair such injuries even when
contained, only to realize after mobilizing the liver that
bleeding will more than likely result in the death of the
patient.
Figure 13.1.
ANSWER:
D
Causes of traumatic injuries in pregnancy are similar to those
in the general population. Blunt trauma is the most common
cause: 49% motor vehicle crashes, 25% falls, 18% assaults,
4% penetrating wounds, and 1% bums. The principle of
managing a pregnant patient after injury is to focus on the
patient, which yields the best outcomes for both mother and
baby.
In this hemodynamically normal patient, without evidence of
free rupture and ongoing bleeding, the normal anatomy may
contain the bleeding such that tamponade results, and surgical
intervention is not necessary. Admission with close
observation in the trauma intensive care unit is the correct
choice in this patient. Damage-control laparotomy with
perihepatic packing, primary repair of the injury,
endovascular stenting, and atriocaval shunt placement are
techniques that may be used if this patient requires operative
intervention for uncontrolled bleeding and hemodynamic
abnormality.
Splenic injury management includes observation,
angioembolization, splenorrhaphy, and splenectomy. A
hemodynamically normal patient with a splenic injury is
usually managed nonoperatively with a high success rate. At
the other end of the spectrum is a patient who presents in
hypovolemic shock that is not responsive to resuscitation.
Admission hypotension is a strong predictor of the need for
splenectomy, and most of these patients will require
splenectomy. A distal pancreatectomy is rarely required
unless a pancreatic injury is also present.
13. A 21-year-old unrestrained woman was involved in a
high-speed motor vehicle collision. She is 16 weeks pregnant.
She is awake and alert, complaining of left-sided chest pain
and left upper quadrant abdominal pain. Her only external
injuries are right lower extremity abrasions from the knee to
the foot and a left knee abrasion. Her blood pressure is
reported as 70 mm Hg systolic by prehospital providers, and
she was given 1000 mL of lactated Ringer solution in transit.
Her first emergency department vital signs include a blood
pressure of 98/60 mm Hg and a pulse of 88 beats per minute.
She is taken to the CT scanner, where her blood drops
pressure transiently to 70 mm Hg systolic. She responds to
fluid, and a unit of blood is hung, but her heart rate remains
at 110 beats per minute. Her CT scan is shown (figures 13.1).
The next step in her management is
Management controversy surrounds the patient who is
hemodynamically abnormal and responds at least transiently
to resuscitation with a known splenic injury.
Angioembolization is suggested as a management option in
this scenario, especially if a contrast blush is present on CT
scan (figure 13.2).
118
A splenectomy is recommended because these patients are
not candidates for nonoperative management with or without
angioembolization. The importance of observation is stressed
in reports trying to establish a role for angioembolization for
splenic injuries.
In this patient, who has just completed her first trimester, the
goal of treatment should focus on establishing normal
hemodynamics as soon as possible. She has a grade V injury
but is not responding to resuscitation. Early splenectomy
would quickly and reliably restore normal hemodynamics.
Angioembolization exposes the patient to the risks of
radiation to the fetus, complications of the intervention, and
recurrent bleeding. Given the appearance of the spleen on CT
scan, splenorrhaphy is not likely to be possible and would
increase her rate of recurrent bleeding to a higher incidence
than a splenectomy (1% vs 3%).
Figure 13.2. Grade V splenic injury with multiple contrast
14. A 20-year-old man is admitted to the trauma bay in class
IV hemorrhagic shock. A tibial intraosseous (IO) device is
placed for venous access. Which of the following crystalloid
infusion methods is preferred?
blushes.
Angioembolization improves spleen salvage rates for grade
IV and V injuries compared with nonoperative management
(table 13.3). Whether these spleens function normally after
embolization remains unclear. However, in an outcome
study, the rate of splenectomy among patients with a splenic
blush on CT scan was not statistically different among those
patients who had angioembolization versus those patients
who did not. It is clear that proper patient selection remains
the key element for appropriate use of angioembolization in
patients with blunt splenic injury.
Grade
*
I
II
III
A.
B.
C.
D.
E.
35°C fluid by gravity
42°C fluid by pressure infusion pump
42°C fluid by gravity
24°C fluid by pressure bag
45°C fluid by manual syringe
Type-of
Injury
Hematoma
Description
ANSWER:
Subcapsular, <10% surface area
Laceration
Capsular tear, <1 cm parenchymal depth
Hematoma
Subcapsular, 10-50% surface area,
intraparenchymal, <5 cm in diameter
Laceration
1-3 cm parenchymal depth, which does not
involve a trabecular vessel
Hematoma
Subcapsular, >50% surface area or
expanding, ruptured subcapsular or
parenchymal hematoma
>3 cm parenchymal depth involving
trabecular vessels
Numerous sites can be used for intraosseous (IO) access:
anterior tibia, proximal humerus, distal femur, and sternum.
The anterior tibial location is preferred in children. The
proximal humerus should be used only in mature adolescents
and adults. Humeral access is often harder to secure, and
dislodgement may be a problem if the patient is moved. Care
should be taken when placing an IO device to make sure that
it is the correct device for the location.
Laceration
IV
Laceration
V
Laceration
Involving segmental or hilar vessels
producing major devascularization (>25%
of spleen)
Completely shattered spleen
Vascular
Hilar vascular injury, which devascularizes
spleen
* Advance one grade for multiple injuries up to grade III.
Table 13.3. Splenic injury scale.
The alternative is splenectomy, which can be performed in
most institutions without delay with a predictable outcome.
The morbidity is higher with splenectomy than successful
nonoperative
management,
with
or
without
angioembolization. The ideal candidate is a patient with a
splenic injury who remains hypotensive despite resuscitation.
B
Crystalloid fluids (e.g., normal saline) for rapid volume
expansion and viscous drugs and solutions should be
administered under pressure. The pressure is needed to
overcome the resistance in the emissary veins, which lead
from the medullary cavity to the general circulation. The
pressure device used can be an infusion pump, pressure bag,
or manual injection through a syringe and stopcock. The latter
obviously requires a specific individual. While using pressure
infusion devices, constant evaluation for extravasation is
necessary. Extravasation can be detected by swelling around
the infusion site or by higher pressures being needed for
continued infusion.
The use of warmed crystalloid infusions is imperative for
patients in shock. Hypothermia impairs coagulation, causes
vasoconstriction, and promotes acidosis. The lethal triad—
hypothermia, acidosis, and coagulopathy—is associated with
119
hypovolemic shock and commonly leads to aborting
operative therapy in favor of a damage control approach.
Warming all fluid used for resuscitation is imperative.
Pressure infusers not only help when an IO is being used for
access but also can warm the fluid, even at high flow rates.
Most fluid warmers use a set point of 42°C, which is the same
temperature for blood warming. Although the fluid can be
warmed to 42°C, it will lose some heat in the tubing and
usually enters the body just above normal body temperature.
Thus, at very high flow rates with open body cavities, heat
loss may exceed the heat transfer achieved by the fluid.
Temperatures higher than 42°C carry risks of thermal injury.
Esophagoduodenoscopy is not required, although it might be
used to help pass a nasoenteric feeding tube in a patient who
is not totally obstructed but cannot tolerate feedings by
mouth. Radiologic placement of a nasoenteric tube is another
possibility. Enteral feeding is preferred over parenteral, but a
feeding jejunostomy is not preferred early in management
because most patients will not require any operative
procedure.
Exploratory laparotomy is not indicated without a trial of
nonoperative management. Most duodenal hematomas will
resolve in 1 to 3 weeks without surgical intervention. If
duodenal obstruction persists, then surgical intervention is
appropriate. Evacuation of the hematoma is usually not
possible, and neither a duodenoduodenostomy nor a
jejunoduodenostomy effectively treats the obstruction.
In this patient with an IO access and class IV shock, a
pressure infuser should be used for all fluid administration.
16. A 24-year-old man is involved in a motor vehicle crash.
He is intubated at the scene for a Glasgow Coma Scale score
of 7, and 2 large bore intravenous lines are placed. On arrival
to the emergency department, his pupils are equal and
reactive, he has a temperature of 37.8°C, heart rate of 105
beats per minute, blood pressure of 100/60 mm Hg, and SaO2
of 86%, with an FiO2 of 0.6. On arterial blood gas, his pH is
7.45, PaCO2 is 35 mm Hg, pO2 is 57 mm Hg. Point of care
glucose is 185 mg/dL (70-100 mg/dL). What is the next
intervention for this patient?
15. A 23-year-old helmeted motorcyclist is injured after
colliding with a stationary car. He is hemodynamically
normal with a normal focused assessment with sonography
for trauma examination. His chest radiograph shows a small
pulmonary contusion and fractures of right ribs 9,10, and 11.
He is admitted for pulmonary care. On the second day of
hospitalization, the patient develops epigastric fullness and
pain, which is relieved after he vomits bilious material several
times. His white blood cell count and hematocrit are normal.
A CT scan demonstrates a distended stomach with thickening
of the second portion of the wall of the duodenum. What is
the most appropriate next Step in this patient's management?
A.
B.
C.
D.
E.
A.
B.
C.
D.
E.
Exploratory laparotomy
Gastric decompression
Feeding jejunostomy
Esophagogastroduodenoscopy
Parenteral nutrition
ANSWER:
Insulin infusion
Hyperventilation to PaCO2 of 25 mm Hg
Hypertonic saline
Mannitol
Increase FiO2
ANSWER:
E
Trauma is the leading cause of death in patients younger than
45 years. Traumatic brain injury (TBI) is a leading cause of
death. Although many interventions can be undertaken to
prevent TBI, once a TBI occurs, it is up to the surgeon caring
for the patient to prevent secondary injury.
B
Blunt duodenal injury is uncommon. When it does occur,
duodenal hematomas can obstruct the bowel lumen. Often
seen in children, they can also occur in adults after a blow to
the abdomen. Management is usually nonoperative because
the hematoma typically resolves. Most patients will have
signs and symptoms of a bowel obstruction that may present
immediately after injury or may be delayed. CT scanning of
the abdomen in patients after blunt abdominal injury will
often identify duodenal abnormalities consistent with a
duodenal hematoma, including duodenal wall thickening and
paraduodenal edema. Perforation can be excluded when there
is no extraluminal air in the pararenal spaces around the
duodenum.
In 2007, the IMPACT study evaluated the risk of secondary
TBI. In this study, there was a clear link between patient
outcome and the absence of hypoxemia (defined as PaO2 <60
mm Hg) and hypotension (systolic blood pressure of <90 mm
Hg), the presence of hypoxemia alone, the presence of
hypotension alone, and the presence of both. In the scenario
presented, the patient has a severe TBI with a Glasgow Coma
Scale score of 7. He is normothermic and has asystolic
pressure of 90 mm Hg. He is hypoxemic with a PaO2 of 57.
Thus, to prevent secondary brain injury, the next step would
be to increase his FiO2.
Treatment should begin with gastric decompression. After
gastric decompression, a contrast study is done to identify the
degree of duodenal obstruction. Parenteral nutrition is
required if complete obstruction is present. Enteral nutrition
can be attempted if duodenal obstruction is not complete.
Another cause for poor outcome in TBI is elevated
intracranial pressure. Elevated intracranial pressure can be
manifested by signs on physical exam (dilated pupils) or on
direct measurement of intracranial pressure. In the absence of
120
these findings, hyperventilation, hypertonic saline infusion,
or mannitol would not be indicated. There is no role for the
acute infusion of insulin because his elevated glucose is a
response to injury.
2.
3.
A Cochrane Database Systematic Review of antifibrinolytic
drugs for acute traumatic injury included all randomized
controlled trials of aprotinin and TXA. The authors concluded
that the aprotinin trials did not provide sufficient data
regarding mortality. TXA reduced mortality by 10%. Another
Cochrane Database Systematic Review of antifibrinolytic use
for minimizing perioperative blood transfusion included trials
assessing TXA, aprotinin, and epsilon aminocaproic acid.
The use of these agents was supported for minimizing
perioperative allogenic blood transfusion in adult surgical
patients. Mortality in trauma patients was not assessed in this
review.
17. A 20-year-old otherwise healthy man sustains a gunshot
wound to the abdomen. He is transported to the emergency
department immediately after the shooting. On arrival, he is
lethargic with a systolic blood pressure of 70 mm Hg, a heart
rate of 140 beats per minute, and a distended abdomen.
Massive transfusion protocol is initiated, and the patient is
transported to the operating room for exploratory laparotomy.
In addition to transfusion of blood products and surgical
control of bleeding, what intervention provides a mortality
benefit for this patient?
A.
B.
C.
D.
E.
Recombinant Factor VIIa
Desmopressin acetate
Epsilon aminocaproic acid
Aprotinin
Tranexamic acid
ANSWER:
Although recombinant Factor Vila reduces blood product use,
mortality is not affected. Desmopressin acetate does not
improve mortality in acute trauma.
18. Which of the following injury patterns is the best
indication for resuscitative endovascular balloon occlusion of
the aorta in a patient who presents to the emergency
department in extremis?
E
Primary fibrinolysis is a key component in the
pathophysiology of the acute coagulopathy of trauma, and, as
such, is associated with risk of mortality. In severe trauma,
hyperfibrinolysis is associated with a mortality rate of 70 to
100%. Therefore, using antifibrinolytic agents to manage
acute coagulopathy of trauma is plausible.
A.
B.
C.
D.
E.
Two landmark studies—the Clinical Randomization of an
Antifibrinolytic in Significant Hemorrhage (CRASH)-2 and
Military Application of Tranexamic Add in Trauma
Emergency Resuscitation (MATTERS)—demonstrated
improved mortality with the administration of the
antifibrinolytic agent tranexamic add (TXA) in civilian and
military trauma. Bleeding adult trauma patients who present
with systolic blood pressure less than 90 mm Hg, heart rate
of at least 110 beats per minute, or both, may benefit from
TXA administration, with a reduction in 28-day all-cause
mortality. TXA has the greatest impact reducing death in
cases of severe shock (systolic blood pressure <75 mm Hg).
Early TXA (<1 hour after injury) results in the greatest
bleeding-related death reduction. TXA administered from 1
to 3 hours after injury also reduces bleeding-related death but
to a more modest degree. TXA administered more than 3
hours after injury appears to increase risk of death due to
bleeding. TXA is not associated with increased vascular
occlusive events.
Gunshot wound to the neck
Blunt cardiac injury
Blunt thoracic aortic injury
Stab wound to the chest
Unstable pelvic fracture
ANSWER:
E
Hemorrhage is the leading cause of death in trauma patients.
Noncompressible truncal hemorrhage is a particularly vexing
problem, because progression to profound shock and death
can be rapid, and the offending injuries are not amenable to
direct tamponade. Proximal aortic cross-clamping via
resuscitative thoracotomy allows establishment of temporary
hemodynamic stability as a bridge to definitive injury repair
for patients in extremis from profound hemorrhagic shock.
An emerging alternative to resuscitative thoracotomy in the
trauma patient is resuscitative endovascular balloon
occlusion of the aorta (REBOA). This technique has been
used in vascular surgery for the past 20 years, and its
application is now expanding to trauma. REBOA is a
minimally invasive procedure that uses a transfemoral
balloon catheter, which is rapidly inserted retrograde and
inflated for aortic occlusion. For control of pelvic
hemorrhage, the balloon is inflated between the lowest renal
artery and the aortic bifurcation (aortic zone III). For pelvic
hemorrhage, balloon inflation occurs between the left
subdavian artery and the celiac trunk (aortic zone I). Balloon
Current recommendations for the use of TXA in trauma based
on the CRASH-2 trial are as follows:
1.
established fibrinolysis via thromboelastography (LY30
>3%).
Administer only if less than 3 hours after injury.
Use a dose of 1 g intravenously over 10 minutes followed
by 1 g intravenously over 8 hours.
Administer to adult trauma patients with severe
hemorrhagic shock (systolic blood pressure <75 mm
Hg), with known predictors of fibrinolysis, or with
121
occlusion should not occur between the celiac trunk and the
lowest renal artery (aortic zone II). Balloon deployment in
REBOA controls inflow and stems hemorrhage, provided that
the balloon is inflated proximal to the injury, allowing time
to proceed to definitive injury repair in the operating room,
interventional radiology, or hybrid suite. The use of REBOA
in these situations is attractive, yet further assessment of
outcomes is needed based on recent literature.
20. The pictured injury (figure 20.1 and figure 20.2) occurred
with a circular saw. The patient is hemodynamically normal.
You are in a small community hospital, 250 miles from a
hospital with a replantation program. Which of the following
is the most appropriate management?
A. Wrap the hand in gauze moistened with saline or Ringer
lactate solution, place in a sealed plastic bag, and pack
on dry ice for transport.
B. Wrap the hand in gauze moistened with a dextrose 5% in
water solution, place in a sealed plastic bag, and pack on
dry ice for transport.
C. Wrap the hand in gauze moistened with saline or Ringer
lactate solution, place in a sealed plastic bag, and
immerse in ice water for transport.
D. Place the hand in iced saline for transport.
E. Place the hand in dry ice for transport.
REBOA should be confined to patients in extremis due to
exsanguinating hemorrhage arising below the diaphragm.
The 2 primary indications for use of REBOA in trauma are
extremis due to profound hemorrhagic shock secondary to
pelvic trauma or abdominal hemorrhage. REBOA should not
be used in patients with blunt cardiac or aortic injury and
penetrating neck or chest trauma. Patients with
cardiovascular collapse due to a major intrathoracic injury
should undergo resuscitative thoracotomy, because the heart
and thoracic vasculature can be directly accessed for
clamping, release of cardiac tamponade, and temporization of
cardiac and hilar injuries.
19. A 30-year-old man is involved in a head-on motor vehicle
crash. He is placed in a cervical collar. On arrival to the
emergency department, he is awake and alert with normal
vital signs. His secondary survey identifies no injuries. Which
of the following findings indicates imaging of his cervical
spine is needed?
A.
B.
C.
D.
E.
Glasgow Coma Scale score of 15
Normal neurologic examination
Absence of midline c-spine tenderness
Inability to cooperate with the exam
No evidence of intoxication
ANSWER:
Figure 20.1.
D
Although injury to the cervical spine is quite rare (occurring
in 1-3% of multisystem blunt trauma patients), missing a
clinically significant injury can have disastrous
consequences. To address the question of which patients
require screening, the National Emergency X-Radiography
Utilization Study (NEXUS) decisionmaking rules were
developed, applied, and studied prospectively. A patient who
is awake, alert, and evaluable with no distracting injuries and
neurologically normal with no midline cervical spine
tenderness meets the NEXUS guidelines for removing the
collar and clearing the neck clinically. Patients who cannot
co-operate with the examination, whether by intoxication or
other conditions, cannot be cleared clinically. Current
recommendations for those who do not meet the criteria for
clinical clearance is to proceed with imaging. CT scan is more
sensitive than plain films.
Figure 20.2.
ANSWER:
C
Hand replantation is a viable option for many patients who
have not had severe mangling or crush injuries. Replantation
of a midpalmar amputation has a reported success rate of
122
86%. The surgeon or emergency medicine physician called
on to manage the patient before transfer to a replantation
center must be familiar with management of the amputated
tissue. Cooling the tissue is essential to reduce metabolic
demand before revascularization. Dry ice is too cold and runs
the risk of freezing the specimen, whether in a bag or not.
Placing the hand directly into the saline will lead to
maceration of the tissues. The preferred method of transport
is wrapped in physiologic solution moistened gauze, sealed
in a plastic bag, and immersed in ice water.
monitoring and immediate access to surgery, selective
management may have a role.
21. An 18-year-old man presents with a stab wound to the
left chest. He is hemodynamically normal. His chest x-ray is
normal. Focused assessment with sonography for trauma
shows pericardial fluid. The next step in management should
be
A.
B.
C.
D.
E.
A.
B.
C.
D.
E.
22. A 25-year-old man is involved in a motor vehicle crash
and has the pelvic fracture seen on the x-ray (figure 22.1). His
blood pressure is 80/50 mm Hg and his heart rate 120 beats
per minute; he is diaphoretic. His abdomen is nontender and
nondistended, and he has a negative focused assessment with
sonography for trauma exam. What intervention is the best
next step in management of his pelvic fracture?
Exploratory laparotomy
-Pelvic angioembolization
Preperitoneal packing
Application of an external pelvic binder
Resuscitative endovascular balloon occlusion of the
aorta
median sternotomy.
subxiphoid pericardiotomy.
cardiopulmonary bypass.
transesophageal echocardiogram.
left anterolateral thoracotomy.
ANSWER:
B
A subxiphoid pericardiotomy is indicated for this patient to
confirm the cause of the abnormal focused assessment with
sonography for trauma (FAST) exam.
In recent years, support has emerged for the selective
management of hemopericardium. The patient in this
scenario is hemodynamically normal with a positive
pericardial view on FAST exam. Neither transesophageal
echocardiogram nor cardiopulmonary bypass are indicated as
the next step. Mandatory exposure of the heart by either
median sternotomy or left anterolateral thoracotomy leads to
a high nontherapeutic operation rate. One report revealed that
38% of sternotomies for positive subxiphoid windows had no
cardiac or great vessel injury requiring repair.
Figure 22.1.
ANSWER:
D
The patient described has a pelvic fracture associated with
likely hemorrhagic shock (figure 22.2) and no findings that
would make intraperitoneal injury the leading differential
diagnosis. The first step in management for this patient is
application of an external pelvic binder (figure 22.3). An
external pelvic binder can be applied in the emergency
department with no preparation and with a minimum of
training. It immediately decreases the volume of the pelvis
and tamponades pelvic fracture bleeding.
As early as 1995, in a report on echocardiography for
penetrating heart trauma, 4 cases of pericardial irrigation
without sternotomy were reported. In a 2014 randomized
trial, hemodynamically normal patients with penetrating
chest trauma had a 24-hour period of observation, then went
on to subxiphoid pericardial window. Only 6 of 191 patients
observed became hemodyamically abnormal and went to
surgery before the end of the observation period. If blood, but
not active bleeding, was found at pericardiotomy, patients
were randomized to sternotomy or irrigation and drainage
without sternotomy. The nonstemotomy group had a shorter
intensive care unit stay and hospital stay, no life-threatening
complications, and no mortality. The only death was in the
sternotomy group, from a missed iatrogenic internal
mammary injury. In centers with the capability for intensive
123
23. A 7-year old boy presents several hours after blunt trauma
to the abdomen caused by falling onto his bicycle handlebars.
He initially went home, but his mother brought him to the
hospital for repetitive emesis of clear fluid. He has a bicycle
handlebar imprint in his epigastrium and peritonitis on exam.
CT scan reveals a transected pancreas to the left of the
mesenteric vessels (figure 23.1). What is the best next step?
A. Splenic-preserving distal pancreatectomy
B. Diagnostic endoscopic retrograde cholangiopancreatography with placement of a pancreatic stent
C. Laparoscopy and drain placement
D. Bedrest, nasogastric tube decompression, and central
catheter placement for parenteral nutrition
E. Bed rest, nasogastric tube decompression, and
nasojejunal tube placement for enteral feeds
Figure 22.2. Pelvic radiograph showing multiple fractures
(arrows).
Figure 23.1.
Figure 22.3. Radiograph after placement of an external pelvic
ANSWER:
binder. Note the compression of the urinary bladder, most likely
caused by a pelvic hematoma.
A
The management of blunt pancreatic trauma in children is
controversial, with some surgeons advocating operation and
others nonoperative management for high-grade injuries.
Pancreatic trauma has 5 grades: grade I is a minor contusion
or superficial laceration without duct injury, grade II is a
major contusion without duct injury or tissue loss, grade HI
is distal transection or parenchymal injury with duct injury,
grade IV is a proximal transection involving the ampulla, and
grade V is massive disruption of the pancreatic head (table
23.2).
Exploratory laparotomy in this situation would be
nontherapeutic and would delay treatment of the bleeding
pelvic fracture. Pelvic angioembolization and preperitoneal
packing are both good options for controlling pelvic fracture
bleeding, but both require at least a short time for preparation
and execution. Resuscitative endovascular balloon occlusion
of the aorta is a promising technique that can stop arterial
inflow to the pelvis. It too has a short, but real, time to prepare
and execute.
124
Grade
*
I
II
Type-of
Injury
Hematoma
Description
Laceration
Superficial laceration without duct injury
Hematoma
Major contusion without duct injury or
tissue loss
Major laceration without duct injury or
tissue loss
Distal transection or parenchymal injury
with duct injury
Laceration
24. A 24-year-old man presents to the emergency department
with a single gunshot injury to the right frontotemporal region
of the head. He has no other signs of injury. His heart rate is
40 beats per minute, and his blood pressure is 180/110 mm
Hg. What is the most appropriate next step in management of
his head injury?
Minor contusion without duct injury
III
Laceration
IV
Laceration
Proximal transection or parenchymal
injury involving ampulla
V
Laceration
Massive disruption of pancreatic head
A.
B.
C.
D.
E.
Intravenous mannitol 1 g/kg
Supine position
Intravenous esmolol
Hyperventilation to PaCO2 less than 25 mm Hg
Intracranial pressure monitoring
ANSWER:
A
Management of severe brain trauma continues to evolve as
new data regarding outcomes are published. Current Brain
Trauma Foundation recommendations for the use of mannitol
or hypertonic saline as hyperosmolar therapies are limited
due to the lack of sufficient evidence from comparative
studies demonstrating improved clinical outcomes. However,
the group continues to recommend the use of mannitol before
intracranial pressure (ICP) monitoring in patients with signs
of transtentorial herniation or progressive neurologic
deterioration not attributable to extracranial injury. Thus,
waiting to place an ICP monitor is not recommended.
Furthermore, randomized controlled trials have not
demonstrated an improved outcome with ICP monitoring.
The utility of mannitol over hypertonic saline has not been
demonstrated, thus either may be used. Patients should have
the head of bed elevated to decrease ICP when possible.
Blood pressure should not be lowered, as an elevated blood
pressure is a natural response to increasing ICP.
Hyperventilation to low normal levels (30-35 mm Hg) is a
short-term adjunctive therapy for patients with evidence of
severe brain injury. However, level I data are lacking, and
recent studies demonstrated cerebral ischemia, thus altering
current expert opinion. Hyperventilation to PaCO2 of less
than 25 mm Hg for prolonged periods is certainly not
recommended.
* Advance one grade for multiple injuries up to grade III.
Proximal pancreas is to the patients’ right of the superior
mesenteric vein.
Table 23.2. Pancreatic injury scale.
A review article summarizing pediatric blunt pancreatic
trauma management noted controversy in the management of
higher-grade injuries but reported that patients with ductal
disruption may benefit from operative intervention. If the
ductal injury is proximal, a subset of patients may benefit
from endoscopic retrograde cholangiopancreatography and
stent placement in centers where this procedure can be
offered
to
children.
If
endoscopic
retrograde
cholangiopancreatography is not available, nonoperative
management with expected pseudocyst formation and later
drainage is favored over operation on the pancreatic head.
Although the spleen might be removed in adults with this
injury, distal pancreatectomy with preservation of the spleen
is favored in children with duct disruption.
In a study comparing 39 children with grade HI to IV
pancreatic injuries from 2 institutions that had different
philosophies regarding management, those managed
operatively had either distal pancreatectomy (12 patients) or
only a drain placement (3 patients). Patients managed
nonoperatively (24 patients) were
started on parenteral nutrition and nasogastric suction.
Compared with early operation, nonoperative management
was associated with an 8-times greater risk of complications
and 13 more days on parenteral nutrition, with a trend toward
considerably longer hospitalization. Two-thirds of patients
who had drain placement only also had complications, which
accounted for half of the complications in the entire operative
group. Pseudocyst development was the second most
common complication after central venous catheter infection.
None of the operative patients developed a pseudocyst, and
central catheter infections were more frequent in
nonoperative patients, likely related to a longer catheter
duration for prolonged parenteral nutrition.
25. A 10-year-old boy presents after a firework exploded
near his hands and chest. He has first- and second-degree
bums to the right chest (5% total body surface area). He had
no loss of consciousness, was not thrown, and has no other
external, signs of trauma. This occurred outdoors, and there
are no carbon deposits in his mouth or nose There are no
fractures on radiographic studies. On postinjury day 1, he
develops a cough and requires supplemental oxygen via nasal
cannula. His chest x-ray (figure 25.1) demonstrates
A.
B.
C.
D.
E.
125
pneumonia.
atelectasis
pulmonary contusion.
inhalation injury.
thermal injury to the lung parenchyma.
The primary blast injury is a blast-induced pressure wave,
which extends outward from the explosion. As this intense
overpressurization wave passes through the body, it results in
injuries involving the lungs, gastrointestinal tract, and
tympanic membranes due to disruption at air-water
interfaces. The resulting lung injury is a pulmonary contusion
that is not associated with rib fractures. The secondary injury
is due to shrapnel resulting in penetrating wounds. The
tertiary blast injury is blunt force trauma due to the body
being thrown against a stationary environmental object.
Quaternary blast injuries include bums, crush, and toxic
inhalation.
In this case, the explosion was adjacent to the chest wall, and
the primary blast injury resulted in a pulmonary contusion
(figure 25.3). Pulmonary contusions take time to develop and
may not be evident on initial radiographic imaging.
Figure 25.1.
ANSWER:
Although a large explosion, particularly in a closed space,
may force heated gas indirectly into the distal airways
resulting in a thermal burn, this is not the situation in the case
presented.
D
Explosions can occur in the civilian setting. The resulting
physical trauma is due to any combination of 4 distinct
mechanisms, which occur nearly simultaneously (table 25.2).
Category
Characteristics
Body Part Affected
Types of Injuries
Primary
Unique to high- order explosives,
results from the impact of the
overpressurization wave with
body surfaces.
Gas-filled structures are
most susceptible: lungs,
gastrointestinal tract, and
middle ear
•
•
Results from flying debris and
bomb fragments
Any body part may be
affected
•
Secondary
•
•
•
Blast lung (pulmonary barotrauma)
Tympanic membrane rupture and middle
ear damage
Abdominal hemorrhage and perforation
Globe (eye) rupture
Concussion (traumatic brain injury without
physical signs of head injury)
•
Penetrating ballistic (fragmentation) or
blunt injuries
Eye penetration (can be occult)
Tertiary
Results from being thrown by the
blast wind
Any body part may be
affected
•
•
Fracture and traumatic amputation
Closed and open brain Injury
Quaternary
* Ail explosion- related injuries,
illnesses, or diseases not due to
primary, secondary, or tertiary
mechanisms
* Includes exacerbation or
complications of existing
conditions
Any body part may be
affected
•
•
•
•
Burns (flash, partial, and full thickness)
Crush injuries
Closed and open brain Injury
Asthma, chronic obstructive pulmonary
disorder, or other breathing problems from
dust, smoke, or toxic fumes
Angina
Hyperglycemia
Hypertension
•
•
•
Table 25.2. Mechanisms of blast injury.
126
centrally located within the spinal cord, involvement of the
upper extremities is typical. The patient presents with
bilateral upper extremity loss of sensation and weakness.
Lower extremity function is typically preserved, and the
patient usually is able to walk.
Brown-Sequard syndrome results from hemitransection of
the spinal cord with unilateral damage to the corticospinal
tract, spinothalamic tract, and dorsal columns. Presenting
symptoms include ipsilateral loss of proprioception, motor
function, and light touch sensation with contralateral loss of
pain and temperature sensation.
Posterior cord syndrome is rare and is the result of injury to
the dorsal columns. This causes loss of proprioception and
vibration, although motor function is preserved. Many
patients have difficulty ambulating due to the loss of
proprioception.
Figure 25.3. Pulmonary contusion.
Being outdoors when an explosion takes place makes
inhalation injury less likely. The time course would be
unusual for pneumonia to develop, and it is not consistent
with the chest x-ray findings. Atelectasis can occur,
particularly if there are associated fractures. However, in this
case, the pulmonary contusion is isolated to where the
explosion occurred adjacent to the chest wall and lacks the
plate-like appearance more suggestive of atelectasis.
Conus medullaris syndrome usually results from injury to the
T12 and Ll-L2 regions of the spine. Typical symptoms
include loss of sensation in the saddle region with bowel and
bladder dysfunction. The patient does not typically have
lower extremity weakness.
Items 26-28
Each lettered response may be selected once, more than once,
or not at all.
A.
B.
C.
D.
E.
Anterior cord syndrome
Brown-Sequard syndrome
Central cord syndrome
Conus medullaris syndrome
Posterior cord syndrome
26. Bilateral loss of motor and sensation in the upper
extremities
27. Ipsilateral paralysis and loss of proprioception with
contralateral loss of pain and temperature sensation
28. Loss of sensation in the perineum, bladder dysfunction
ANSWERS:
C, B, D
Anterior cord syndrome classically occurs from a vascular
injury that results in anterior spinal artery insufficiency. This
leads to ischemia involving the anterior two-thirds of the
cord. It can also occur after blunt trauma to the anterior spinal
cord. The patient presents with loss of motor function as well
as a loss of pain and temperature sensation below the level of
the injury. Proprioception and the ability to sense vibration
are preserved.
Central cord syndrome is usually caused by hyperextension
of the cervical spine in a patient with pre-existing cervical
spondylosis. Because the upper extremity axons are more
127
Trauma Part II
2. A 22-year-old man presents with an isolated 2-cm stab
wound to the mid left neck just anterior to the
sternocleidomastoid muscle. His vital signs are normal. His
voice is normal. On physical exam, there is a small hematoma
(3 cm) that is stable in size with no signs of bleeding. The
remainder of his exam is normal. The best next step in his
management is
ITEMS 1-28
For each question, select the best possible response.
1. A 22-year-old pregnant woman presents after being
ejected from a truck at highway speed. She is intubated with
a Glasgow Coma Scale score of 3T, pulse of 120 beats per
minute, and blood pressure 105/45 mm Hg. Her fundal height
is 6 cm superior to the umbilicus. A fetal heart-rate monitor
was placed. Which of the following statements is true?
A.
B.
C.
D.
E.
A. Normal heart rate of her fetus should be 85 to 100 beats
per minute
B. She should be placed in the right lateral decubitus
position.
C. Anemia of pregnancy is anticipated due to decreased red
cell mass.
D. CT scan of the abdomen and pelvis are contraindicated.
E. The fetus has likely reached the stage of viability.
ANSWER:
esophagogastroduodenoscopy.
local wound exploration.
CT angiogram.
catheter-based angiography.
formal neck exploration.
ANSWER:
C
Historically the initial evaluation and management of
penetrating wounds to the neck was driven by 3 factors:
presence or absence of hard signs, location of injury, and
mechanism of injury (stab or gunshot wound).
E
Hard signs of vascular or aerodigestive tract injury (e.g.,
active bleeding, expanding or pulsatile hematoma, air
bubbling in the neck) require urgent operative management
by formal neck exploration. Patients with "soft" signs (e.g.,
small, nonexpanding hematoma, hoarseness, odynophagia)
can be selectively evaluated and managed. In this group of
patients (hemodynamically normal with only soft signs),
multidetector CT angiogram is an excellent screening tool
with sensitivity, specificity, positive predictive value, and
negative predictive value all greater than 90%, especially
related to vascular injuries. It is important to remember that
this is a screening exam and any concerns for aerodigestive
tract injury after the CT scan should be specifically evaluated.
Thus, esophagogastroduodenoscopy could be indicated based
on the CT scan finding but would not be the next step in this
situation.
Trauma is the leading cause of nonobstetric mortality for
pregnant women. Injury affects 1 in 12 pregnant women and
has a major impact on maternal morbidity and fetal outcome.
With a few exceptions, the diagnosis and management of the
traumatically injured pregnant patient is the same as for
nonpregnant patients. Due to uterine compression of the
inferior vena cava, those in more advanced stages of
pregnancy should be placed in the left lateral decubitus
position to relieve this compression and allow for better
venous return. Placement in the right lateral decubitus
position has the opposite effect.
Although there is concern about the teratogenic effects of
ionizing radiation, this risk is highest during the period of
organogenesis that occurs between 5 and 10 weeks gestation.
At 20 weeks gestation, the fundal height is palpable at the
umbilicus. Thereafter, it increases by 1 cm per week. In this
patient with a fundal height 6 cm superior to the umbilicus,
the predicted gestational age would be 26 weeks. Therefore,
CT scan of the abdomen and pelvis would be safe, with a fetal
exposure of only 3.5 rads.
Local wound exploration without imaging is contraindicated
and risks bleeding and loss of airway if an occult major
arterial injury is present. Catheter-based angiography would
be used if a specific vascular injury amenable to endovascular
treatment was identified. However, use as a screening tool
would not identify other injuries and would risk the
complications of catheter-based angiography. Formal neck
exploration in patients with only soft signs would be
nontherapeutic in up to 80%. Thus, for this patient with
normal vital signs and a small, stable hematoma, CT
angiogram is the best next step in management.
With advances in neonatal care, the age of viability continues
to decline but is usually considered to be more than 23 weeks
gestation or a fundal height 3 cm above the umbilicus.
Red blood cell mass increases approximately 30%, but blood
volume increases 40 to 50%. As a result there is a relative
anemia of pregnancy. The normal fetal heart rate is 120 to
160 beats per minute. Monitoring fetal heart rate is needed to
detect decelerations, tachycardia, bradycardia, or loss of
variability, which are associated with adverse fetal outcomes.
Traditionally, the initial evaluation and management of
penetrating neck injuries was based on the zone of injury:
•
•
•
129
Zone I: manubrium to cricoid
Zone II: cricoid to angle of the mandible
Zone III: above the angle of the mandible
However, this zone-based approach had several challenges.
Although it worked reasonably well with stab wounds,
gunshot wounds presented problems. Specifically, gunshot
wounds may traverse several zones, especially if the
trajectory is transcervical. Another approach suggests initial
evaluation and management should be guided by symptoms
and clinical findings and not the zone of injury. Patients with
hard signs of injury should undergo operative management.
The only caveat is zone HI injuries, which can be very
difficult to reach operatively and may be best approached by
endovascular techniques. Patients with soft signs should have
screening CT angiogram as their first investigation.
Asymptomatic patients with normal exams can be managed
expectantly.
4. For a patient requiring operative care for a traumatic
pancreas injury, the strongest predictor of mortality is
A.
B.
C.
D.
E.
ANSWER:
A
Pancreatic and pancreaticoduodenal injuries are challenging
and require an organized and systematic approach. Mortality
rates are 12 to 18% and are higher for blunt trauma compared
with penetrating trauma. Shock on admission is the strongest
predictor of mortality for patients with operative pancreas
injuries. Injuries to the body are easier to address and have
lower mortality than injuries to the head of the pancreas. The
number of intra- and extra-abdominal injuries does not
influence mortality, although associated vascular injuries and
increasing age does increase risk of mortality.
3. A 25-year-old man sustained a gunshot wound to the left
lower quadrant of the abdomen. He arrives with a normal
primary survey, including normal vital. signs, but he has
diffuse abdominal tenderness on secondary survey. During
operative exploration, you find a through-and-through injury
to the sigmoid colon with loss of more than 50% of the wall.
There is local spillage of solid stool, minimal blood loss, and
no other major injury. The next operative step is
5. Which of the following is most predictive of failure of
nonoperative management for blunt splenic trauma?
A. primary repair of injury.
B. resection of the injury, end colostomy with blind distal
colon.
C. resection of the injury, end colostomy and mucus fistula.
D. resection of the injury with anastomosis.
E. resection of the injury, planned second look.
ANSWER:
shock on admission.
injury to the body of the pancreas.
associated liver injury.
blunt mechanism of injury.
number of extra-abdominal injuries.
A.
B.
C.
D.
E.
D
Hemodynamic normality on admission
Grade IV splenic injury
Hemoperitoneum
Age younger than 40 years
Arterial contrast blush on CT scan
ANSWER:
Traumatic colon injuries can be classified as nondestructive
(amenable to primary repair) or destructive (require
resection). This patient has a destructive injury with loss of
more than 50% of the circumference of the colon. Primary
repair would likely result in narrowing or stricture. Thus,
resection is required.
B
major injuries, the next step after resection should be
anastomosis. In this situation, the leak rate is less than 10%.
An end colostomy, with or without a mucus fistula, would
require another laparotomy for this patient and is
unnecessary. Likewise, damage control surgery and a second
look are not required in a patient with an uncomplicated preand intraoperative course.
Splenic injury can range from small to moderate lacerations
or subcapsular hematomas, typically grades I to III. In
hemodynamically normal patients, these injuries can often be
successfully treated nonoperatively (bed rest, hemodynamic
and laboratory monitoring).
More significant lacerations involving segmental or hilar
vessels producing devascularization of more than 25% of the
spleen (grade IV) or a completely shattered spleen (grade V)
are more often treated with splenectomy, but grade IV and V
injuries in hemodynamically normal patients can be managed
with nonoperative management with or without arterial
embolization. Routine selective arterial embolization is
associated with lower failure rates of nonoperative management
in grade IV and V injuries (table 5.1).
After segmental resection, the question becomes how and
when to reconstruct the colon. The 3 main options are (1)
diversion (Hartmann procedure), (2) anastomosis, and (3)
anastomosis with diversion. The main determinants of these
choices are hemodynamic status and overall burden of injury.
In this patient with a normal primary survey, including
normal vital signs, minimal blood loss, and no other major
injuries, the next step after resection should be anastomosis.
In this situation, the leak rate is less than 10%. An end
colostomy, with or without a mucus fistula, would require
another laparotomy for this patient and is unnecessary.
Likewise, damage control surgery and a second look are not
required in a patient with an uncomplicated pre- and
intraoperative course.
130
Grade
*
I
II
III
Type
of
Injury
Hematoma
Description
Laceration
Capsular tear, <1 cm parenchymal depth
Hematoma
Subcapsular,
10-50%
surface
intraparenchymal, <5 cm in diameter
Laceration
1-3 cm parenchymal depth, which does not
involve a trabecular vessel
Hematoma
Subcapsular, >50% surface area or
expanding,
ruptured
subcapsular
or
parenchymal hematoma
>3 cm parenchymal depth involving
trabecular vessels
Laceration
IV
Laceration
V
Laceration
Subcapsular, <10% surface area
area,
Involving segmental or hilar vessels
producing major devascularization (>25% of
spleen)
Completely shattered spleen
Vascular
Hilar vascular injury, which devascularizes
spleen
* Advance one grade for multiple injuries up to grade III.
Table 5.1. Splenic injury scale.
Risk factors with strong evidence for failure of nonoperative
management include age older than 40, grade III or higher
injury, or injury severity scores of at least 25. Moderate
evidence exists for intraparenchymal contrast blush or
transfusion of more than 1 unit of blood being risk factors. No
evidence for failure of nonoperative management exits for
hemodynamic status on admission, emergency department
mean blood pressure, hemoglobin, hematocrit level, or heart
rate.
6. In patients with hemorrhagic shock due to severe trauma,
what is the recommended approach to plasma, platelets, and
packed red blood cell (PRBC) product resuscitation during
the initial phase of management?
introduced complexity into the process of resuscitation.
Crystalloid, albumin, and artificial starch solutions also
became popular as volume expanders during this time.
Experience over the previous 30 years and several recent
publications have resulted in some significant changes in the
practice of resuscitation, which in many ways now resembles
the historic use of whole blood. These studies demonstrated
that for the acutely bleeding patient in hemorrhagic shock,
empiric resuscitation with packed red blood cells (PRBCs)
together with both plasma and platelets is the optimal initial
management.
PRBCs do not contain clotting factors or platelets; therefore,
they should not be used in isolation in the resuscitation of
acutely bleeding patients. Waiting for laboratory tests before
initiating blood product resuscitation, even if they are point
of care, is both unnecessary and potentially harmful in these
circumstances. Furthermore, plasma and platelets should be
given concurrently with PRBCs to avoid significant
"imbalances" in the ratio of blood products at any given time.
7. A 28-year-old man presents with a single stab wound to
the left chest just medial to the nipple. On examination, he is
pale, diaphoretic, and lethargic. His heart rate is 120 beats per
minute, his blood pressure 98/65 mm Hg, and his respiratory
rate is 24 breaths per minute. A chest x-ray is taken with a
paperclip on the site of the chest wound (figure 7.1). Focused
assessment with sonography for trauma examination is
performed and is positive for pericardial fluid. What is the
best next step in the management of this patient?
A. Chest CT scan
B. Left tube thoracostomy
C. Median sternotomy
D. Subxiphoid pericardial window
E. Pericardiocentesis
A. PRBCs alone until surgical hemostasis is achieved
B. PRBCs for hemoglobin less than 7 g/dL, platelets when
count is less than 150,000/mm3
C. Plasma, platelets, and PRBCs all given empirically
D. Plasma after 10 units of PRBCs, platelets after 20 units
of PRBCs
E. Plasma and platelets, only if coagulation studies are
abnormal
ANSWER:
C
Hemorrhage results in nearly 50,000 deaths and 2 million
years of life lost annually in the United States. Up to 64% of
these deaths are potentially preventable. Blood product
resuscitation is essential to the survival of patients in
hemorrhagic shock, and recent advances in the practice of
resuscitation will hopefully reduce the number of preventable
deaths.
Historically, whole blood was used for resuscitation;
however, the advent of component therapy in the 1960s and
its increased use through the 1970s and 1980s suddenly
Figure 7.1.
ANSWER:
C
This patient has signs and symptoms consistent with
obstructive shock from pericardial tamponade (diaphoresis,
131
lethargy, tachycardia, narrowed pulse pressure, tachypnea).
No pneumothorax is seen on the chest x-ray; therefore, a left
chest tube is not specifically required. The cardiac silhouette
bears mention in this case. There is a relatively normal
contour suggesting that (1) the patient does not have purely
hemorrhagic shock and (2) if there is a pericardial effusion, it
is likely acute because the pericardium has not had time to
expand. His focused assessment with sonography for trauma
(FAST) exam is grossly positive in the pericardial window,
which is 97% specific for a cardiac laceration. Thus, no
further diagnostic measures (e.g., pericardial window, chest
CT scan) or temporizing therapeutic interventions (i.e.,
pericardiocentesis) are needed in this patient if surgical
capability for pericardial decompression and cardiac repair is
immediately available.
this situation, securing the airway as a first step in
management is most important Given level HI trauma center
resources, transport of this patient is necessary. Maintaining
adequate oxygenation during transport will help prevent
secondary brain injury.
Securing the airway with endotracheal intubation is the most
reliable method to maintain oxygenation and ventilation,
given the GCS score, and it should be the first step in
management. Further management may include a trauma CT
scan if there will be a delay in transfer. A CT scan of the head
can be performed, with the results being communicated to the
receiving hospital. CT scan gives the most information in a
short period of time about the status of the brain, and this
information should be communicated expeditiously to the
consulting neurosurgeon for decision making and treatment
planning for interventions before transfer.
The diagnostic accuracy of pericardial FAST is degraded in
patients with a hemothorax or if adequate subxiphoid or
parasternal views cannot be obtained due to subcutaneous
emphysema or body habitus. If adequate windows can be
obtained and fluid is visualized in a patient with a clinical
picture consistent with tamponade, further evaluation is not
needed. In equivocal cases, gated cardiac CT scan of the
chest, pericardiocentesis, or pericardial window can be used
to guide further therapy. If a pericardial effusion is identified
and surgical resources are not available, temporizing
pericardiocentesis can buy time until the patient can be
transported to a center with surgical resources.
9. A 30-year-old woman is a restrained driver in a motor
vehicle crash. On initial evaluation, she has a Glasgow Coma
Scale score of 15, and she is hemodynamically normal. She
has mild tenderness on abdominal palpation and no seat belt
sign. An intravenous contrast-enhanced CT scan of her
abdomen. and pelvis reveals no injury to liver, spleen, or
kidneys. The radiologist reports moderate amounts of free
fluid in the pelvis with mesenteric stranding in the small
bowel. The next appropriate step in her management is
A.
B.
C.
D.
E.
8. A 46-year-old man is involved in a high-speed motorcycle
crash; he was not helmeted. He is brought to a level III trauma
center 1 hour after the event. The patient has a patent airway,
bilateral breath sounds, and a systolic blood pressure of 100
mm Hg on initial survey. He is resuscitated with a good
response. He is noted to have a comminuted open left femur
fracture and withdraws to pain when the limb is placed in
traction. His eyes are closed and open only to painful stimuli;
he verbalizes that he is in pain but cannot converse normally.
This man's degree of head injury can be assessed by his
calculated Glasgow Coma Scale score of 10. The next step in
management is
A.
B.
C.
D.
E.
ANSWER:
D
Blunt hollow viscus injury (BHVI) is reported in 1 to 5% of
blunt trauma patients. These injuries may be easily missed,
but specific findings on CT scan can suggest the presence of
BHVI. Free air or extravasation of enteric contrast are
obvious signs, but many patients have more subtle findings.
Often the only irregularity is bowel wall thickening, irregular
contrast enhancement of the bowel wall, mesenteric
abnormality, or unexplained free fluid in the abdomen. No
combination of findings is pathognomonic for BHVI. The
surgeon must have a high index of suspicion for these injuries
and consider the mechanism of injury and physical
examination findings in decisionmaking (figure 9.1). This
patient has tenderness on abdominal exam and concerning
findings on CT scan, both of which are predictors of BHVI.
Patients in whom there is a concern for BHVI should undergo
operative exploration. In selected patients, diagnostic
laparoscopy may be appropriate; however, an exploratory
laparotomy will allow careful inspection of the stomach,
small bowel, and colon.
measure intracranial pressure.
observe the patient.
perform a brain CT scan.
contact a level-I trauma center for transfer.
intubate the patient.
ANSWER:
admission with observation.
CT scan with oral and rectal contrast.
focused abdominal sonogram for trauma.
exploratory laparotomy.
discharge.
E
This patient is a head-injured, multisystem blunt force trauma
victim who is initially stable after resuscitation. His initial
Glasgow Coma Scale (GCS) score, which is an easily
reproducible method to evaluate degree of neurologic
disability is scored as (Eyes or E = 2) + (Verbal or V = 4) +
(Motor or M = 4) is 10. He has a depressed sensorium, and in
132
Rib fixation is especially useful in patients who are not able
to progress to spontaneous ventilation after initially being
intubated and mechanically ventilated. Maximal benefits
occur when the procedure is done early after injury, usually
within 3 to 5 days.
11. A 39-year-old man sustained a single stab wound to the
left chest. On arrival to the emergency department, he was
pulseless. Emergency department thoracotomy is indicated in
this patient only if he
A. did not require prehospital cardiopulmonary
resuscitation.
B. has signs of life in the emergency department.
C. has a tension hemothorax.
D. has a primary cardiac injury.
E. is neurologically intact.
Figure 9.1. Blunt bowel and mesenteric injury.
Further diagnostic imaging with focused abdominal
sonogram for trauma or CT scan with enteric contrast is
unlikely to provide clarification of a BHVI and may delay
time to diagnosis. Any delay in diagnosis of a BHVI increases
the morbidity and mortality associated with the injury. In
patients with a high suspicion of injury, a period of
observation or discharge may increase the overall
complication rate.
ANSWER:
The 2015 guidelines for resuscitative thoracotomy by the
Eastern Association for the Surgery of Trauma (EAST)
reviewed 72 studies and 10,238 patients who underwent
resuscitative thoracotomy. Based on the evidence, EAST
strongly recommended that patients who present pulseless
with signs of life after penetrating thoracic injury undergo
resuscitative thoracotomy.
Signs of life, often used interchangeably with vital signs,
were defined by the American College of Surgeons
Committee on Trauma in 2001: pupillary response,
spontaneous ventilation, presence of carotid pulse,
measurable or palpable blood pressure, extremity movement,
or cardiac electrical activity.
10. A 60-year-old man is admitted with a flail right chest
after a fall from a roof. He has been intubated and
mechanically ventilated for 3 days with no improvement in
spontaneous breathing trials. He is being considered for rib
stabilization Compared with nonoperative management, the
operative fixation of rib fractures in patients with a flail chest
after blunt trauma reduces
A.
B.
C.
D.
E.
Prehospital
cardiopulmonary
resuscitation,
tension
hemothorax, primary cardiac injury, and neurologic status are
not valid indicators for the use of resuscitative thoracotomy
because they do not predict survival in patients with traumatic
arrest.
mortality.
narcotic requirements
spirometry volumes.
pneumonia.
costs.
ANSWER:
B
Focused assessment with sonography for trauma (FAST)
exam to evaluate the presence or absence of cardiac motion
may be useful in determining whether traumatic arrest
patients should undergo resuscitative thoracotomy. A singleinstitution study of 187 blunt and penetrating traumatic arrest
patients (77% required resuscitative thoracotomy) confirmed
that overall survival was only 3.2%. Cardiac motion on FAST
exam was 100% sensitive and 73.7% specific for the
identification of survivors and organ donors. If both cardiac
motion and pericardial fluid were absent on FAST exam,
survival was zero. FAST therefore represents an effective
method to identify trauma patients with higher likelihood of
survival who may benefit from resuscitative thoracotomy.
D
Several randomized clinical trials compared the operative
fixation of rib fractures with nonoperative management after
blunt trauma. These trials have consistently demonstrated that
surgical rib fracture fixation after blunt chest trauma reduces
pulmonary morbidity, in particular the incidence of
pneumonia and the duration of mechanical ventilation.
Compared with nonoperative management, surgical rib
fracture fixation increases spirometry volumes, but it does not
decrease mortality rates or narcotic requirements. Hospital
costs are higher with surgical rib fixation than with
nonoperative treatment.
133
Items 12-15
Each lettered response may be selected once, mare than once,
or not at all.
A.
B.
C.
D.
E.
and distal thoracic esophagus. The lateral position has the
disadvantages of not being tolerated well by
hemodynamically unstable patients, providing very limited
access to the abdomen, and providing practically no access to
the opposite thorax. A right anterior thoracotomy is relatively
rarely used in trauma. It does achieve access to the right lung
parenchyma and provides limited access to the lung hilum.
Left anterior thoracotomy
Left posterolateral thoracotomy
Median sternotomy
Right anterior thoracotomy
Right posterolateral thoracotomy
The access to the heart is limited. It does have the advantage
of being performed in the supine position. Right anterior
thoracotomy is used in a hemodynamically compromised
patient with injuries limited to the right chest.
12. Gunshot to left chest with arrest in trauma bay
13. Stab wound 1 cm left of sternum, blood pressure 96/80
mm Hg, heart rate 125 beats per minute, positive pericardial
effusion on ultrasound
16.
A 54-year-old man is involved in a motor vehicle
collision. Portable anteroposterior chest radiograph reveals a
widened mediastinum. He has no other injuries. The next step
in his evaluation should be
14. Gunshot to back with injury to midesophagus by contrast
study
15. Blunt injury to aorta with contained rupture 1 cm distal
to the left subclavian artery
ANSWERS:
A.
B.
C.
D.
E.
A, C, E, B
The choice of incision in the treatment of thoracic trauma is
vitally important in achieving adequate exposure to allow for
optimal results.
chest CT scan with intravenous contrast.
transthoracic echocardiography.
transesophageal echocardiography.
arch aortography.
upright posterior-anterior and lateral chest radiograph.
ANSWER:
The left anterior thoracotomy is the incision of choice in an
emergency department resuscitative thoracotomy and is
performed in a supine position with the patient7 s arm
abducted. Typically, it is begun at the sternal edge in the
fourth or fifth intercostal space in a sharp arc to the axilla.
This allows adequate access to the heart, lower thoracic aorta,
and left lung. It can be performed quickly without specialized
instruments. Left anterior thoracotomy does not provide good
exposure to the upper chest cavity or mediastinum. It can be
easily converted to a bilateral thoracotomy (clamshell) with
extension across the lower sternum. The supine position also
allows easy access to the abdomen, if necessary.
A
Although most patients with blunt thoracic trauma do not
incur aortic injuries, a high index of suspicion must be
maintained. The presence of a widened mediastinum on chest
radiograph is a sensitive but nonspecific marker of traumatic
aortic injury and mandates further investigation to rule out
injury.
Trauma patients are frequently unable to tolerate repetition of
the chest radiograph in the upright posterior-anterior and
lateral position, so repeat x-ray is not recommended. Also,
given concern for blunt aortic injury, x-ray will not provide
any new or additional information. Transthoracic
echocardiography is not able to visualize the aorta at the most
common site of injury (just distal to left subclavian artery).
Initial enthusiasm for transesophageal echocardiography is
tempered by concerns about widespread availability and
accuracy. Both types of echocardiography are highly
dependent on the skills of the sonographer.
A median sternotomy allows the best exposure to the heart
and great vessels. It can be extended to a midline laparotomy,
if required. Exposure of the lung parenchyma is limited.
Median sternotomy is a poor choice for esophageal access.
The need for instrumentation to divide the sternum may limit
the ability to perform this incision quickly. Morbid wound
complications are a risk in emergency situations.
CT scan of the chest with intravenous contrast has supplanted
traditional arch aortography for 3 reasons: (1) additional
information on associated injuries is available; (2) staff are
readily available to perform and interpret the studies; and (3)
contrast exposure is lower.
The right posterolateral thoracotomy is performed in a lateral
position. It provides access to the right lung, including the
hilum, diaphragm, trachea, and mid-esophagus. The lateral
position may not be tolerated by hemodynamically
compromised patients, due to a reduction in venous return.
The access to the opposite thorax and abdomen is very
limited.
The left posterolateral thoracotomy is performed in a lateral
position. It provides exposure to the left lung, including the
hilum, the aortic arch, descending thoracic aorta, diaphragm,
134
Items 17-18
A helmeted 14-year-old sustains a hard tackle during football
practice and is unconscious for approximately 1 minute. He
admits to feeling dizzy after he was helped to the sidelines,
but he wants to finish the practice. His Glasgow Coma Scale
score is 15.
cervical spine is warranted. Although MRI is more sensitive
at detecting complicated traumatic brain injury compared
with CT scan, most patients presenting with concussive
symptoms do not require neurological imaging studies. If
level of consciousness is of concern, the athlete with the
concussion should be imaged and observed in a hospital
setting; frequent awakening is no longer recommended
17. Which of the following statements is true regarding his
care?
Anyone who has sustained a concussive traumatic brain
injury has a 2 to 5.8 times higher risk of sustaining another
concussion. Recovery is not always quick. Protracted
recovery is associated with numerous factors, including
previous concussion, the severity of posttraumatic symptoms,
female sex, a pre-existing learning disorder, and certain
positions of football teams (quarterback, receivers, running
backs). Although wearing a helmet decreases severe impact
injuries such as skull fracture, most helmets currently in use
do not reduce the incidence or severity of concussion.
Catastrophic traumatic brain injury is more likely in younger
athletes. One hypothesis is that the immature brain has less
cognitive reserve compared with a more mature brain.
A. Returning to finish the practice is allowable.
B. Immediate head CT scan should be performed.
C. Sideline evaluation should include new learning and
concentration assessments.
D. Glasgow Coma Scale is a sensitive indicator of
concussion.
E. His parents should awaken him every 2 hours for the next
24 hours.
18. Regarding his prognosis, which of the following
statements is true?
A. Wearing a helmet eliminates the risk of chronic
headache.
B. His risk of sustaining another concussion is increased.
C. His recovery would be more rapid than if he were
younger.
D. His mood will be altered for the next week.
E. He can return to normal practice and play in 7 days.
ANSWERS:
Limitations on returning to school are not defined. Students
with traumatic brain injury may require academic
accommodations for an extended period of time. Alterations
in sleep pattern, mood, and headache are common after a
concussion and may last weeks or months. Return to play
should be individualized, with gradual monitored
reinstatement of activity. If symptoms recur or increase with
activity level, activity progression should cease until
symptoms resolve.
C, B
Sports-related concussions affect nearly 4 million athletes per
year. Because most symptoms of neurologic dysfunction
resolve within 7 to 10 days, pressure to allow young athletes
to return to play early is substantial. However, symptom
resolution alone is not indicative of complete recovery from
a traumatic brain event. Current standards of care are based
on a paradigm of rest and gradual return to play. The final
decision regarding returning to play depends on findings
related to cognitive and physical assessments. The
recommendations make it clear that when a potential
concussion is diagnosed, the athlete should not return to play
on the same day.
19. A 35-year-old woman was in a head-on motor vehicle
collision. She is hemodynamically normal but requires
intubation due to a decrease in mental status. Before
intubation, she was moving all 4 extremities. She had a
cervical collar placed by prehospital personnel. The earliest
her cervical collar may be removed is
A. when she is able to participate in a thorough neurologic
exam.
B. after obtaining normal plain films (3 views) of her
cervical spine.
C. after obtaining a normal CT scan of her cervical spine.
D. after obtaining a normal MRI of her cervical spine.
E. immediately because no cervical collar is required.
Ideally, sideline evaluation after a sports-related loss of
consciousness should include an assessment of vision
changes with oculomotor testing, balance and postural
stability, and mental status questions specific to situation,
including new learning (e.g., word recall, listing months of
the year backward), and concentration assessments.
Standardized concussion and balance scoring systems, when
combined, increase the sensitivity and specificity of a
concussion diagnosis. A Glasgow Coma Scale of 15 is
reassuring with respect to general verbal, motor, and pain
responses but is insufficient to rule out a concussive event.
Skull fractures, epidural or subdural hematomas, and cerebral
edema are rare in this setting, although palpation of the
ANSWER:
C
In the awake and alert blunt trauma victim, the cervical spine
can be evaluated with a thorough physical exam followed by
a CT scan, if necessary. Both the National Emergency XRadiography Utilization Study (NEXUS) and Canadian
Cervical Spine Rules (CCR) are acceptable methods of
clearing a cervical spine clinically. Both rules require the
patient to have no neurologic defects, midline cervical
135
tenderness or pain with active motion, distracting injuries, or
altered mental status. If any of these are present, dedicated
axial imaging is recommended. The CCR also recommends a
CT scan for certain high-risk mechanisms or populations.
Axial imaging has completely replaced plain x-rays because
of its substantially higher sensitivity and specificity for
injuries.
on parenchymal injury and ductal injury (table 20.1).
Essentially, grade I and II injuries spare the duct, grade HI
and IV involve the main pancreatic duct, and grade V injuries
represent a massive disruption of the head of the pancreas.
Type-of
Grade* Injury
I
Hematoma
Laceration
II
Hematoma
The obtunded population presents a different diagnostic
dilemma. The risk of a missed cervical spine injury must be
weighed against the potential complications of cervical spine
immobilization, including increases in intracranial pressure
related to decreased internal jugular venous return and
occipital and submental decubiti. Until recently, axial
imaging was considered insufficient to clear the cervical
spine in the obtunded patient. This was due to the risk, albeit
very low, of a clinically significant missed injury. Several
studies quoted missed injury rates (with normal CT imaging)
of approximately 3 in 1000. It was unclear what percentage
of these injuries were clinically significant. A recent review
by the Eastern Association for the Surgery of Trauma
reversed this recommendation based on the nearly 100%
negative predictive value of CT imaging and the increased
risks and cost added by adding MRI to the diagnostic workup
of patients with a normal CT scan. The authors noted that this
recommendation may result in a "non-zero" rate of clinically
significant injury.
Laceration
Laceration
IV
Laceration
V
Laceration
*Advance one grade for multiple injuries up to grade III.
Proximal pancreas is to the patients right of the superior
mesenteric vein.
Table 20.1. Pancreatic injury scale.
In hemodynamically normal patients, CT imaging is the
diagnostic modality of choice. Modem axial imaging can
detect pancreatic injuries with a sensitivity and specificity of
nearly 50% and 80%, respectively. Current, 64-slice
multidetector CT scanners can detect injuries to the
pancreatic duct with very high rates of sensitivity and
specificity.
To be considered a diagnostically appropriate CT of the
cervical spine, the study must have slices from the skull-base
to the first thoracic vertebrae with sagittal and coronal
reconstructions.
Grade I and II injuries diagnosed on CT scan can be safely
managed nonoperatively. Several studies note very low
pancreas-related morbidity from observed, low-grade
injuries. In studies where grade I and II injuries were explored
after axial imaging, CT scan was 91% sensitive and specific
for identification of duct injury. If the pancreatic duct is not
well visualized on initial imaging, additional imaging such as
dedicated pancreas CT scan, magnetic resonance
cholangiopancreatography, or endoscopic retrograde
cholangiopancreatography (ERCP) is recommended before
exploration based on initial findings alone. For grade I or II
injuries found at the time of exploration, nonresectional
management with or without a closed suction drain is
recommended.
20. A 25-year-old man presents to the trauma bay after
crashing his dirt bike. He is hemodynamically normal, and his
only complaint is moderate abdominal pain. Axial imaging
reveals an injury to the mid body of the pancreas. Which of
the following statements is true regarding the management of
blunt pancreatic injuries?
A. Grade III and IV injuries encountered during exploration
should undergo resection.
B. Grade I and II injuries should be routinely explored.
C. A draining Roux-en-Y limb should be sewn to the
pancreatic margin after resection.
D. Grade III and IV injuries encountered on imaging are
managed with observation.
E. Octreotide should be routinely administered after distal
pancreatectomy.
ANSWER:
III
Description
Minor contusion without duct injury
Superficial laceration without duct injury
Major contusion without duct injury or tissue
loss
Major laceration without duct injury or tissue
loss
Distal transection or parenchymal injury with
duct injury
Proximal transection or parenchymal injury
involving ampulla
Massive disruption of pancreatic head
Based on recommendations from the Eastern Association for
the Surgery of Trauma (EAST) group, grade HI and IV
injuries diagnosed on axial imaging warrant surgical
exploration. The alternative to surgical exploration in the
setting of a presumed duct injury is ERCP with placement of
a pancreatic stent. The results from nonoperative
management were not statistically worse on any single
outcome studied in the EAST guidelines; however, based on
a cumulative trend toward worse outcomes, the conditional
recommendation of surgical resection was made. Part of the
basis for this recommendation was the high rate of treatment
failures in the nonoperative group leading to delays in
definitive management and increased patient morbidity.
A
Pancreatic injuries as a result of abdominal trauma, while
rare, can lead to significant morbidity and mortality if not
managed appropriately. The American Association for the
Surgery of Trauma grading scale classifies the injuries both
136
•
For grade III and IV injuries found at the time of surgical
exploration, resection is recommended. Injuries to title left of
the superior mesenteric vein should undergo a distal
pancreatectomy. Stump closure with a draining roux limb
does not improve leak rates. Closure techniques such as
simple duct ligation with mattress suture of the pancreatic
body have equivalent results. The routine use of octreotide
postoperatively does not reduce fistula rates and is not
recommended. Injuries to the right of the mesenteric vein are
more complex, and surgical resection will be based on
injuries to the surrounding structures.
A 24- to 48-hour period of monitoring is suggested.
The American Burn Association formula for fluid
resuscitation for a patient with more than 20% total body
surface area (TBSA) recommends starting with 2 to 4
mL/kg/TBSA. This fluid resuscitation should not include
albumin. Patients with a high-voltage injury may present with
myoglobinuria and will require additional fluid resuscitation,
but a routine increase in fluids is not indicated. Immediate
systemic antibiotic therapy is not indicated. Electrical injury
patients with persistent myoglobinuria or extremity
compartment syndrome should be evaluated for fasciotomy
and muscle debridement.
21. A 100 kg 23-year-old man was working on an outlet
inside his house when a flash fire caught his shirt on fire. The
patient developed 7% total body surface area second-degree
burns to his hands, arms, and chest. Which of the following
statements about treatment for his bums is true?
22. A 13-year-old boy was involved in a head-on collision.
He was restrained in the back seat with a lap belt. He was
evaluated in the emergency department, and his workup was
unremarkable other than mild tenderness and a small bruise
from the seat belt across his upper abdomen. The next day, he
has nausea, vomiting, and mild abdominal pain. CT scan
revealed complete bowel obstruction at the second and third
portion of the duodenum. In addition to a nasogastric tube,
what is the most appropriate next treatment for this patient?
A. A prophylactic bilateral escharotomy of the hands and
arms should be performed.
B. An electrocardiogram is not necessary.
C. His fluid resuscitation amount should be increased by
25%.
D. Immediate fluid resuscitation should start with albumin.
E. Systemic antibiotics are not recommended.
ANSWER:
A.
B.
C.
D.
E.
E
It is important to classify electrical injuries based on the
voltage. Low-voltage injuries are less than 1000 V; highvoltage injuries are 1000 V and higher. Low-voltage bums are
generally localized. In the United States, domestic wiring
operates on an alternating current at 120 V. Therefore, this
bum is classified as a low-voltage burn. Low-voltage burns
are usually localized to the point of contact. If contact with
the low-voltage source is prolonged, deep tissue damage
occurs with little lateral extension.
Urgent laparotomy
Trickle gastric feeds
Laparoscopy
Parenteral nutrition
Surgical jejunostomy
ANSWER:
D
Duodenal injuries are uncommon, partly because of the
duodenum's protected location in the retroperitoneum. A
hemodynamically normal patient with a CT scan showing a
duodenal injury should be further evaluated. Laparoscopy is
not recommended because a full Kocher maneuver must be
performed, or a small laceration may be missed.
High-voltage bums are associated with deep extension and
underlying tissue damage similar to a crush injury. Because
of this, these patients are at risk for the development of
compartment syndrome during the first 48 hours after an
injury. High-voltage bums are more common in industrial
settings and not in homes. With high-voltage injuries,
escharotomy is not sufficient. A fasciotomy is required for
compartment syndrome treatment.
Grade I and grade II hematomas are diagnosed by CT scan,
and initial management should be expectant with nasogastric
decompression and oral intake withheld. A hematoma may
progress to obstruction. The period for development of this
obstruction varies from hours to days. Nonoperative
management is appropriate for up to 14 days; therefore,
urgent laparotomy is not indicated in this hemodynamically
normal patient. After 14 days, operative management should
be performed, which includes drainage of the hematoma and
simple repair.
Cardiac abnormalities occur after both low- and high-voltage
injuries Electrocardiogram should be part of the initial
evaluation in all patients. Prolonged cardiac monitoring is not
usually necessary but suggested when the following are
present:
•
•
•
Cardiopulmonary resuscitation in the field
Early enteral feeding has benefits, and a jejunostomy is
preferred. Trickle gastric feeds are not appropriate due to the
obstruction. In the absence of a jejunostomy, parenteral
nutrition should be started. Parenteral nutrition should be
continued until the obstruction resolves, thus allowing for
Loss of consciousness
Electrocardiogram abnormality or evidence of ischemia
Documented dysrhythmia before or after admission to
the emergency department
137
enteral feeding by mouth. If the obstruction persists beyond
14 days, a surgical jejunostomy is appropriate.
Lateral compression (LC): anterior injury-rami fractures
(a) LC I: sacral fracture on side of impact
(b) LC II: crescent fracture on side of Impact
(c) LC III: type I or II injury on side of impact with contralateral
open-book injury
23. A 74-year-old man is involved in a high-speed motor
vehicle collision. After initial resuscitation, he is
hemodynamically normal and the only abnormality identified
on evaluation is a pelvic fracture (figure 23.1). What is the
next step?
A.
B.
C.
D.
E.
Anterior-posterior compression (APC): anterior injury =
symphysis diastasis/rami fractures
(a) APC I: minor opening of symphysis and sacroiliac (SI) joint
anteriorly
(b) APC II: opening of anterior SI, intact posterior SI ligaments
(c) APC III: complete disruption of SI joint
External pelvic fixation
CT scan with intravenous contrast
Angiographic embolization
Exploratory laparotomy
Placement of pneumatic antishock garments
Vertical shear (VS type)
Vertical displacement of hemipelvis with symphysis diastasis or
rami fractures anteriorly, iliac wing, sacral facture or SI
dislocation posteriorly
Combination (CM type): any combination of above injuries
Table 23.1. Young-Burgess classification of pelvic fractures.
After initial evaluation, in hemodynamically normal patients,
a CT scan with intravenous contrast of the abdomen and
pelvis should be obtained. If there is no evidence of active
bleeding, patients who continue to be hemodynamically
normal should be treated with pelvic stabilization. As long as
they remain hemodynamically normal, these patients do not
require angiographic embolization, exploratory laparotomy,
external pelvic fixation, or pneumatic antishock garments.
Figure 23.1.
ANSWER:
24. A 19-year-old man was intubated in the field. He arrives
at the emergency department with a single gunshot wound to
the chest just medial to the left nipple. He is unresponsive and
has bilateral breath sounds, a heart rate of 140 beats per
minute, and no detectable blod pressure. A focused
assessment with sonography for trauma exam demonstrates a
large hemopericardium. What is the best next step in the
management of this patient?
B
Pelvis injuries from high-energy trauma are frequently
associated with concomitant internal injuries, including
hemorrhage, intra-abdominal injuries, bladder/urethral
injuries, and nerve deficits secondary to disruption of the
pubic ring.
A.
B.
C.
D.
E.
After consideration to airway, breathing, and circulation,
initial inspection for concern of a pelvic injury should include
a search for external bleeding, blood at the penile
meatus/vagina, and the position of the lower extremities and
iliac crests. A common classification system for pelvic
fractures is the Young-Burgees classification (table 23.1).
Pericardiocentesis
Resuscitative left anterolateral thoracotomy
Subxiphoid pericardial window
Median sternotomy
Resuscitative endovascular balloon occlusion of the
aorta
ANSWER:
A
This patient presents in extremis after a gunshot wound in the
"cardiac box." A focused assessment with sonography for
trauma exam demonstrates a hemopericardium leading to a
diagnosis of pericardial tamponade, which is consistent with
the clinical picture. This patient has a penetrating cardiac
injury that needs to be addressed immediately to prevent
complete cardiac arrest. A left anterolateral thoracotomy will
allow for rapid and adequate exposure of the heart and
138
pericardium to allow decompression and repair of any injury.
A median sternotomy provides excellent exposure for this
kind of injury but requires equipment that may not be
immediately available in an emergency department and takes
longer to perform than a thoracotomy.
The ankle-brachial index (ABI) is an important part of the
physical examination in patients with knee dislocations.
Abnormal ABI values (<0.9) help identify patients with
vascular injury and can obviate routine angiography in all
patients with a history of knee dislocations and ligamentous
injury. An angiogram is the gold-standard to help identify
peripheral vascular injury, but it is invasive and involves the
use of nephrotoxic contrast agents. In patients with palpable
pulses and no hard or softs signs of vascular compromise,
obtaining an ABI before committing to angiographic imaging
is prudent.
A pericardiocentesis in this scenario will result in an
excessive amount of time lost. Moreover, it is diagnostic only
and still requires an urgent operation to fix the cardiac injury.
Similarly, a pericardial window is a reasonable diagnostic
procedure if the patient already had a laparotomy ongoing and
there is suspicion for pericardial tamponade. In this scenario,
the diagnosis is clear and diagnostic procedures will delay
definitive management and potentially lead to patient
mortality.
Routine surgical exploration of patients with knee
dislocations is not indicated when there is no evidence of
impending vascular compromise.
Resuscitative endovascular balloon occlusion of the aorta
(REBOA) involves access through a patient's femoral artery
and placement of an occlusive balloon in the aorta to stem
bleeding distal to the occlusion. Chest trauma that could
result in aortic or cardiac injury is a contraindication for the
use of REBOA because it may exacerbate the injury.
26. A 25-year-old woman with a gunshot wound to her
abdomen and a 4-hour transport time arrives with a
temperature of 35°C. She has a blood pressure of 80/40 mm
Hg and a heart rate of 140 beats per minute. As you prepare
for surgery, which of the following statements is true
regarding treatment of her hypothermia?
25. A 23-year-old man arrives awake and alert after a singlevehicle motorcycle crash. He complains of severe right knee
pain associated with edema around the knee joint. X-rays
demonstrate no evidence of a fracture. Pedal pulses are
palpable and symmetric. The next step in management is
A.
B.
C.
D.
E.
A. Warm insulating blankets and a warming gown device
prevent further heat loss.
B. Blood products should not be heated to more than 30°C.
C. Peritoneal lavage with warm saline will normalize her
core temperature
D. Correcting the blood loss does little to treat the
hypothermia.
E. Airway rewarming effectively raises core temperature.
continuous leg compartment pressure measurement.
arterial vascular duplex the next day.
ankle-brachial index.
right lower extremity angiography.
surgical exploration of the popliteal artery.
ANSWER:
ANSWER:
C
A
Hypothermia (<35°C) is an independent predictor of
mortality. Hypothermia after traumatic injury results from
blood loss and is compounded by a cold external environment
at the time of injury and during the phases of treatment.
Warming the local environment—the trauma bay or the
operating room—may help to prevent further heat loss but
will not correct the hypothermia. Similarly, warm insulating
blankets and wanning gown devices will help prevent further
heat loss. Correcting the blood loss with transfusion and
stopping the bleeding will correct the hypothermia. Peritoneal
lavage with warm saline and airway rewarming will not
increase the core temperature of a patient sufficiently to treat
hypothermia.
Severe knee pain, edema, and the lack of a fracture raise the
possibility of significant ligamentous instability and a history
of knee dislocation. Knee dislocations are notorious for
causing popliteal artery injuries, which need to be ruled out
early in the evaluation to prevent the potential for irreversible
vascular compromise. Palpable pulses indicate that distal
perfusion is maintained and no acute ischemia is present;
however, they do exclude the presence of a clinically
significant popliteal injury.
The measurement of compartment pressures is relevant when
there is high suspicion for the development of leg
compartment syndrome, such as with high-grade tibial
fractures. When elevated compartment pressures are found,
early fasciotomies are prudent. Continuous measurement of
compartment pressures will not help in the diagnosis of a
popliteal vascular injury.
Transfused blood products should be warmed to a normal
body temperature before transfusion, because transfusing
cold products will decrease the core temperature. Packed red
blood cells are usually refrigerated at 20 to 25°C and fresh
frozen plasma is stored at 0 to 5°C. Rapid transfusers can heat
to 37°C and transfuse a whole unit within a few minutes.
Rewarming is imperative in traumatically injured patients.
A vascular duplex study can identify flow-limiting lesions.
Obtaining the study 24 hours after admission is too late and
may result in significant ischemia if an injury is missed.
139
27. A 24-year-old man presents to the emergency department
after a motor vehicle. collision. There is a spider-web pattern
on his side of the windshield, but he denies loss of
consciousness. He follows commands, his eyes
spontaneously open, and he speaks in clear but nonsense
phrases. His primary and secondary surveys are otherwise
negative. A CT scan of his head is normal. After a few hours,
his Glasgow Coma Scale score (GCS) is 15. With regard to
management this patient, which of the following statements
is true?
A.
B.
C.
D.
E.
He is at no risk for future neurologic symptoms.
He is still at significant risk for sudden death.
Seizure prophylaxis is indicated for 3 months.
Long-term effects can include cognitive changes.
Symptoms rarely occur if GCS is 15.
ANSWER:
Figure 28.1.
D
This patient has a mild traumatic brain injury or a concussion.
A concussion does not require the patient to have lost
consciousness. The fact that his Glasgow Coma Scale score
returned to normal quickly and his head CT scan was normal
should not reassure the clinician that no traumatic brain injury
exists.
Although he is not at risk for sudden death due an intracranial
hemorrhage, he is still at significant risk for morbidity and
future symptoms. This does not include seizures, however, so
seizure prophylaxis is not indicated. His symptoms are more
likely to present as headaches, photophobia, difficulty
concentrating, amnesia, tinnitus, and gait instability. These
symptoms are not always self-limited. All patients who
experienced a traumatic brain injury should be referred to
someone who treats these injuries to ensure there are no
further symptoms. Symptomatic patients should undergo
cognitive evaluation and probable neuropsychological
rehabilitation. Left untreated, these subtle symptoms may
later manifest as cognitive impairments and mood disorders
that may result in job loss, divorce, and social isolation.
Additionally, these patients should refrain from contact
activities until cleared by healthcare providers.
Figure 28.2.
28. A 21 -year-old woman presents after a motor vehicle
crash at high rate of speed. She was found unresponsive at the
scene with agonal breathing and was intubated. She has
significant facial and head trauma and abdominal road rash.
Her chest x-ray was normal. She is hemodynamically normal.
Focused assessment with sonography for trauma (FAST)
exam reveals no hemoperitoneum. Diagnostic CT scan is
obtained (figures.28.1and28.2). The next step in management
is
A. repeat FAST.
B. diagnostic peritoneal lavage.
C. angiographic embolization.
D. diagnostic laparoscopy.
E. laparotomy.
140
ANSWER:
related to the suspected bowel injury. Urgent laparotomy is
indicated from these findings.
E
Gastrointestinal hollow viscus injury after blunt chest and
abdominal trauma is not common (0.6-1.2% of all trauma
cases). Early recognition of these injuries significantly
reduces morbidity and mortality.
Repeat focused assessment with sonography for trauma
examination will not be helpful, because it is effective in
identifying hemoperitoneum only. Diagnostic peritoneal
lavage is not indicated, because the CT scan findings confirm
hollow viscous injury. Angiographic embolization is
indicated only for hemorrhage related to solid organ injury.
Diagnostic laparoscopy would be helpful if the CT scan
findings were equivocal, but in this case, the CT scan findings
have confirmed bowel injury.
Physical exam is not accurate in detecting these injuries, and
contrast-enhanced CT scan is the mainstay for diagnosis. CT
scan findings in this patient include (1) several foci of
extraluminal gas within the right hemiabdomen and pelvis,
which is relatively confluent anterior to the liver (figure
28.3); (2) small to moderate volume free abdominal fluid,
some of which is high attenuation (figure 28.4); and (3) no
evidence of solid organ injury.
Figure 28.3. Pneumoperitoneum (arrows).
Figure 28.4. Free fluid.
These findings are concerning for bowel injury, with
suspicion directed toward the right colon. Small-volume
high-attenuation free fluid surrounds the liver dome. No
discrete liver laceration is seen, and the free fluid may be
141
Vascular
ITEMS 1-24
For each question, select the best possible response.
ANSWER:
1. When placing a port for outpatient chemotherapy, what
decreases the risk of inadvertent arterial placement?
This patient is presenting with chronic mesenteric ischemia.
Chronic mesenteric ischemia is a disorder in which blood
flow to the intestines is inadequate. The main etiology of
chronic mesenteric ischemia is atherosclerosis of the celiac,
superior mesenteric, or inferior mesenteric arteries. Other rare
causes of chronic mesenteric ischemia include median
arcuate ligament syndrome, vasculitis, or fibromuscular
dysplasia. Nonocclusive mesenteric ischemia is a form of
chronic mesenteric ischemia that occurs in patients with a low
flow state. There is a female preponderance for chronic
mesenteric ischemia.
A.
B.
C.
D.
E.
Internal jugular access
Ultrasound guidance
Fine-gauge needle for initial access
Steep Trendelenburg positioning
Neutral neck position
ANSWER:
B
The most important finding in chronic mesenteric ischemia is
that of postprandial pain, usually occurring after a meal and
lasting anywhere from 90 minutes to 2 hours. Fear of eating
is a result of this pain and leads to patients' eating smaller
meals or missing meals. This leads to weight loss. Patients
may also present with diarrhea. Once a patient reaches endstage chronic mesenteric ischemia, pain patterns may change,
with abdominal pain being more constant. This is due to
blood flow not being able to meet even the most minimal
metabolic demand. Lastly, chronic mesenteric ischemia can
present with ulcers in the stomach. Elderly patients with
ulcers where Helicobacter pylori is negative and there is no
history of NSAID use should undergo screening for chronic
mesenteric ischemia.
Arterial puncture is more likely to occur with an internal
jugular rather than a subclavian approach (3% vs 0.5%).
Subclavian access is more likely to be complicated by
pneumothorax or hemothorax.
Real-time ultrasound prevents arterial injury in the internal
jugular position.It reduces, but does not completely eliminate,
the risk of complications (from 8.4% to 1.4%)
Experience also reduces the risk of complications. Catheter
insertion by a physician with more than 50 prior insertions
compared with a surgeon who has performed fewer than 50
is half as likely to result in a mechanical complication. More
than 3 insertion attempts during one procedure is 6 times
more likely to lead to a complication than when venous
cannulation is achieved on the first attempt. After 3 attempts,
the surgeon should either abort the procedure or ask for
assistance.
The diagnosis of chronic mesenteric ischemia is first and
foremost clinical. Surgeons need to be attuned to the
diagnosis. Duplex ultrasound is a good screening test,
because it does not involve radiation. Unfortunately, it is
operator dependent and thus its use is limited in regions
where experience with ultrasound is not high. CT
angiography is the diagnostic test of choice for chronic
mesenteric ischemia. It not only provides 3-dimensional
imaging of the vasculature of the abdomen but also can rule
out other causes of abdominal pain.
Pressure monitoring, with either column manometry or
pressure transducer before placement of dilator, potentially
prevents arterial injury.
Neck positioning is dependent on the chosen access site.
Generally, it is best to place a roll behind the shoulders. Fine
gauge needle use and steep Trendelenburg positioning are
also good practices and facilitate the procedure, but neither of
these practices definitively reduces the risk of inadvertent
arterial catheterization.
Hepatobiliary scanning is typically used for biliary disease.
The patient in the scenario does not present with typical
biliary symptoms. Upper endoscopy and colonoscopy could
be considered. However, in this patient with postprandial
pain, diarrhea, and weight loss, findings on these tests would
only lead to confusion as to the diagnosis and would delay
treatment of the primary etiology. There is no indication for
diagnostic laparoscopy in this patient.
2. A 77-year-old woman presents with 6 months of
progressive abdominal pain and weight loss, despite a normal
appetite. She reports epigastric and periumbilical pain
approximately 1 hour after eating, with frequent associated
diarrhea. Her physical exam and abdominal ultrasound were
unremarkable. Which of the following would be the next step
in her evaluation?
A.
B.
C.
D.
E.
C
3. A 25-year-old man is shot in the right flank. At the time of
laparotomy, a right medial visceral rotation is performed. A
nonpulsatile, but large and expanding, retroperitoneal
hematoma is visualized. The hematoma is opened, and the
site of bleeding is identified as a laceration of the infrarenal
inferior vena cava involving 75% of its circumference. The
patient's blood pressure is 80/40 mm Hg, his pulse is 115
Hepatobiliary scan
Upper endoscopy
CT angiogram of the abdomen
Colonoscopy
Diagnostic laparoscopy
143
beats per minute, and his hematocrit is 21% (45-52%). The
best next step in the management of this patient is
A.
B.
C.
D.
E.
when simple ligation of the IVC would save the patient's life.
Similarly, although a spiraled saphenous vein graft is a
potential surgical option for repair of the IVC, it is
appropriate only in the elective setting, owing to the time
required to create and place a spiraled saphenous vein
interposition graft.
packing of the retroperitoneal hematoma.
ligation of the inferior vena cava.
suture repair of the inferior vena cava.
a spiraled saphenous vein interposition graft
an endovascular stent graft.
ANSWER:
4. A 70-year-old man has a 4.0-cm abdominal aortic
aneurysm on a surveillance ultrasound. He is asymptomatic.
He is advised to undergo yearly surveillance ultrasound
imaging. Referral for repair of his abdominal aortic aneurysm
should occur when the diameter of his abdominaI aortic
aneurysm is
B
The acute management of penetrating injuries to the inferior
vena cava (IVC) should be guided by both the clinical status
of the patient and the extent of the injury to the IVC. In the
clinical scenario presented, the patient is hypotensive,
tachycardic, and anemic, indicating significant volume
depletion as the result of acute blood loss. Once a patient is
in shock from a penetrating injury to the IVC, progressive
acidosis, hypothermia, and coagulopathy will occur unless
the hemorrhage can be rapidly controlled. Undertaking
complex surgical repairs when a patient is in shock due to
ongoing hemorrhage is not advisable. Given the finding of a
laceration involving 75% of its circumference, the best
surgical intervention for this patient is ligation of the IVC.
A.
B.
C.
D.
E.
4.5 cm.
4.8 cm.
5.1 cm.
5.4 cm.
5.7 cm.
ANSWER:
E
The size at which an abdominal aortic aneurysm should be
repaired was studied in multiple randomized clinical trials.
These trials all used surveillance imaging with abdominal
ultrasound to detect the presence of an abdominal aortic
aneurysm in patients and then followed these patients with
regular scheduled ultrasound scanning over time. These trials,
known as the UK Small Aneurysm Trial (UKSAT), the
Aneurysm Detection and Management trial (ADAM), the
Comparison of Surveillance versus Aortic Endografting for
Small Aneurysm Repair trial (CAESAR), and the Positive
Impact of Endovascular Options for Treating Aneurysms
early trial (PIVOTAL), all concluded that close observation
with periodic ultrasound screening is as safe as either open
repair or endovascular aortic reconstruction, as long as the
abdominal aortic aneurysm is less than 5.5 cm in diameter.
Ligation of the significantly injured infrarenal IVC is an
accepted practice in the setting of damage control
laparotomy, with a reported survival rate of 40%. The most
common morbidity of ligation of the infrarenal IVC is
swelling of the lower extremities. In some patients, this
swelling can be severe enough to cause an acute compartment
syndrome. In most patients, however, ligation of the IVC is
tolerated well. On long-term follow-up, lower extremity
edema or dysfunction is uncommon in patients who have
undergone emergency ligation of the IVC. Concerns
regarding the potential long-term consequences of ligation of
the IVC should not override the need to perform the
procedure when it is necessary to save a patients life.
In this setting, with the finding of a laceration of the infrarenal
IVC involving 75% of its circumference, packing of the
retroperitoneal hematoma will not reliably control the
patients hemorrhage.
The results of these 4 trials demonstrated no advantage to
early repair either via open surgery or endovascular surgery
for smaller abdominal aortic aneurysms, defined as those
between 4.0 and 5.5 cm in size. All of the available evidence
suggests that the optimal care for these patients is routine
monitoring with ultrasound surveillance. More recent clinical
trials focused on the efficacy of endovascular aneurysm
repair for smaller aortic aneurysms have not shown a benefit.
Neither open nor endovascular repair of an abdominal aortic
aneurysm should be undertaken until the aneurysm is more
than 5.5 cm in diameter.
Although an endovascular stent graft may be an attractive
option in some patients, in the acute setting where the
hematoma has been opened and the patient is in shock, there
is not sufficient time to place an endovascular stent graft. An
endovascular repair is more appropriate when an injury to the
IVC is identified preoperatively and the patient has been
adequately resuscitated.
Direct suture repair of the IVC should be reserved for patients
with lacerations that are less than 50% of the circumference
of the IVC, who are not actively in shock, and in whom an
expeditious suture repair of the IVC can be undertaken.
5. A 64-year-old man has a medical history of hypertension,
diabetes, coronary artery disease, and aortic stenosis. He has
undergone coronary artery bypass grafting and aortic valve
replacement. He presents with swelling that involves just his
Complex repairs of the IVC, including the placement of
venous patches or interposition grafts, should be avoided
144
third toe with associated plantar ulcer (figure 5.1). In addition
to antibiotics, what is the next step in his management?
A.
B.
C.
D.
E.
presents with exposed metatarsal and thus carries a diagnosis
of osteomyelitis. For this reason, incision and drainage,
debridement, and hyperbaric therapy would not be indicated.
This patient requires amputation for source control of his
infection. Because only one toe is infected, a transmetatarsal
amputation would be too extensive, whereas a ray amputation
would allow source control and preserve tissue.
Incision and drainage with alginate dressing changes
Debridement with negative pressure wound therapy
Hyperbaric therapy
Transmetatarsal amputation
Ray amputation
Items 6-7
A 65-year-old man undergoes laparoscopic right
adrenalectomy for an enlarging mass. He is managed with
appropriate venous thromboembolism prophylaxis. On
postoperative day 2, he develops new-onset right calf
swelling. Pathology of the adrenal mass is an adenoma.
Duplex studies demonstrate acute obstruction in the right
soleal vein. He is otherwise asymptomatic.
6. How should this patient's clinical condition be managed?
A.
B.
C.
D.
E.
Vitamin K antagonist therapy for 30 days
Observation with repeat duplex study in 2 weeks
Catheter-directed thrombolysis of the lower extremity
Placement of an inferior vena cava filter
Low molecular weight heparin for 30 days
7. On the patient's fourth postoperative day, he develops
hypoxia while remaining normotensive. A CT scan (figure
7.1) is obtained. Which of the following should the patient's
management include?
A.
B.
C.
D.
E.
Figure 5.1.
ANSWER:
E
Placement of an inferior vena cava filter
Anticoagulation therapy for 3 months
Systemic thrombolytic therapy
Pulmonary thromboendarterectomy
Aspirin therapy initiation
This picture is consistent with a diabetic foot infection (figure
5.1). Key point in the evaluation of the patient include extent
of the infection, underlying factors that may have led to the
infection, and microbes that are causing the current infection.
Management of diabetic foot infections involves wound care,
antibiotics, and surgery. Wound care consists of debridement
of necrotic tissue, dressing changes, and elimination of
pressure.
Most diabetic foot infections seen by surgeons are
polymicrobial. Thus, when deciding on antibiotics, broadspectrum coverage should be initiated. On examination, the
surgeon needs to assess the extent of infection and whether
osteomyelitis is present. Evidence of the diagnosis of
osteomyelitis includes grossly visible bone, the ability to
probe bone, ulcer duration longer than 1 to 2 weeks, and ulcer
size greater than 2 cm2. If osteomyelitis is suspected, the
diagnosis can be confirmed with imaging, either plain film or
MRI.
Figure 7.1.
In the scenario presented, the patient is higher risk for
endocarditis due to his aortic valve replacement. Thus, source
control needs to occur quickly. In addition, the patient
ANSWERS:
145
B, B
The diagnosis of venous thromboembolic events and their
management are re-evaluated on a recurring basis, and the
American College of Chest Physicians provides clinical
practice guideline updates based on these reviews. One of the
challenges involves the role of whole-leg ultrasound
examinations (including distal veins) in patients with
suspected deep vein thrombosis (DVT). The current
guidelines discourage routine whole-leg ultrasound
examinations in patients with suspected DVT, which has
reduced the frequency of diagnosing isolated distal DVT.
8. Which of the following statements regarding the use of
temporary arterial shunts in trauma is true?
The rationale is that other assessments may already indicate
that isolated distal DVT are either unlikely to be present or
unlikely to cause complications. Approximately 15% of
untreated isolated distal DVT are expected to subsequently
extend into the popliteal vein and may cause pulmonary
embolism. Therefore, it is unacceptable to neither
anticoagulate nor perform surveillance to detect thrombus
extension. Efficacy of anticoagulant therapy exists for the
treatment of proximal DVT and pulmonary embolism.
Whether the benefits of anticoagulation outweigh its risks in
patients with isolated distal DVT is uncertain because of their
lower risk of progressive or recurrent venous
thromboembolism. In patients with acute proximal DVT of
the leg, the recommendation is for anticoagulant therapy
alone over catheter-directed thrombolysis and the
recommendation is against the use of an inferior vena cava
filter. These recommendations extend to patients presenting
with distal DVTs.
In patients requiring anticoagulation for treatment of DVT of
the leg or pulmonary embolism and no history of cancer, 3
months anticoagulant therapy is recommended with
dabigatran, rivaroxaban, apixaban, or edoxaban over Vitamin
K antagonist therapy (figure 7.2).
ANSWER:
A.
B.
C.
D.
E.
Systemic anticoagulation is required.
The most common site is in the thorax.
Optimal shunt time is less than 6 hours.
Blunt traumatic injuries are the most common indication.
Shunt-related complications occur more frequently in
torso injuries than extremity injuries.
C
Vascular injury during trauma can be treated by ligation,
embolization, stenting, direct repair, or vascular
reconstruction using autologous or prosthetic materials.
Occasionally, temporary intravascular shunts will be required
in the damage control setting or during staged orthopedic
procedures to temporarily re-establish blood flow (figure
8.1).
Figure 8.1. Vascular shunt.
Temporary arterial shunts allow for rapid control of
hemorrhage and re-establishment of distal circulation much
more quickly than a complex arterial reconstruction. This can
allow the surgeon to address other associated injuries and get
the patient to the intensive care unit quickly to correct
hypothermia, coagulopathy, and acidosis. Later, when the
patient has been resuscitated, definitive arterial
reconstruction can be performed. In the setting of
concomitant vascular injury and complex orthopedic injuries,
temporary intravascular shunts can allow for rapid reestablishment of distal perfusion, then orthopedic injuries can
be definitively addressed without concern for disrupting a
newly fashioned arterial repair (figure 8.2). Afterward, the
vascular injuries can be definitively repaired.
Figure 7.2. Deep vein thrombosis of the leg.
There is no role for aspirin as an alternative to anticoagulant
therapy in the acute treatment of venous thromboembolism or
pulmonary embolism. With respect to the role of catheterdirected
thrombolytic
therapy
or
pulmonary
thromboendarterectomy, the recent recommendation is that
few patients with acute pulmonary embolism without
hypotension should be treated with thrombolytic therapy.
146
Aortoenteric fistulas are missed on more than 85% of
endoscopic evaluations, presumably due to their distal nature,
but CT scan has a 93% sensitivity of identifying them. Once
identified, swift action should be taken to avoid
exsanguination. Historically, outcomes for surgery were
poor, but a newer study demonstrated 21% overall mortality
at 30 days, with 0% mortality for those with normal blood
pressure at the time of surgery compared with 60% of those
in hemodynamic shock at presentation.
Figure 8.2. Vascular shunt (plastic tubing) that temporarily
connects 2 severed ends of artery. This allows for rapid reperfusion
of the distal segment and deferring of complicated repair in an
austere forward surgical facility.
Optimal shunt dwell times are not clearly established. No
shunt-related complications are reported with dwell times less
than 6 hours. However, after 6 hours, shunt thrombosis or
dislodgement and distal ischemia are seen more frequently.
These shunt-related complications appear to be related to size
of the vessel being shunted, with smaller vessels having more
complications. Therefore, shunts used in the torso in large
vessels tend to have fewer complications than extremity
injuries. Systemic anticoagulation does not decrease shunt
thrombosis and is not recommended, especially given the
high percentage of associated injuries in these patients. The
role of local and systemic heparin administration during
temporary intravascular shunts placement is controversial.
Placement of temporary intravascular shunts is most common
in the setting of peripheral arterial injuries with a penetrating
mechanism.
Antibiotics and bowel rest are not adequate to prevent
hemorrhage and death because they have not removed the
fistula or the septic focus. Endoscopic clipping is inadequate
to address the infected graft. Although patch angioplasty is a
tempting alternative, most experts agree that the entire graft
must be explanted to eliminate the infection and prevent
farther pseudoaneurysms. After fistula repair and graft
excision, the aorta is oversewn, and the distal perfusion is
restored with an extra-anatomic bypass to avoid graft
contamination.
Endoscopic injection of a fibrin sealant, in combination with
an endovascular stent, is described for thoracic aortoenteric
fistulas. Although such a maneuver is certainly promising,
given its less invasive nature, there is not sufficient evidence
at this point to support its utility in abdominal aortoenteric
fistula.
9. A 78-year-old man presents with a single episode of
hematemesis. He has a history of an open abdominal aortic
aneurysm repair 4 years ago. Esophagogastroduodenoscopy
reveals a dot in the third portion of the duodenum. CT
angiography reveals a fistula between the aorta and
duodenum. What is the most appropriate treatment?
Endovascular stenting of aortoenteric fistulas has emerged as
a reasonable alternative to graft excision and extra-anatomic
bypass. Stenting is associated with lower in-hospital
mortality, but it does carry a nearly 50% risk of reinfection.
Currently, stenting is seen as a bridge to definitive open
surgery and is typically used for patients who are
hemodynamically abnormal or otherwise unfit for the larger
operation.
A. Intravenous antibiotics and bowel rest
B. Esophagogastroduodenoscopy with endoscopic dipping
of the fistula
C. Endoscopic injection of fibrin glue
D. Fistula takedown with patch angioplasty
E. Fistula takedown with graft removal and extra-anatomic
bypass
ANSWER:
10. Among high-risk patients on chemoprophylaxis for
venous thromboembolism prevention, the greatest risk factor
for failure is
E
Upper gastrointestinal hemorrhage is common in elderly
patients. Although these patients often have other potential
causes, including peptic ulcer disease and nonsteroidal antiinflammatory drug use, a history of an abdominal aortic
aneurysm repair should always raise suspicion for an
aortoenteric fistula.
A.
B.
C.
D.
E.
Aortoenteric fistulas are more common in patients with an
open abdominal aortic aneurysm repair compared with those
with an endovascular repair, but they have been described in
both groups. They typically occur 1 to 5 years after abdominal
aortic aneurysm repair, with the most common etiology being
graft infection with an anastomotic pseudoaneurysm that
erodes into the adjacent bowel. Fistulas usually involve the
proximal aortic anastomosis and the distal duodenum.
cumulative missed doses.
trauma.
epidural catheter use.
male sex.
BMI greater than 30.
ANSWER:
A
Venous thromboembolism (VTE) events remain a major
cause of potentially preventable morbidity and mortality in
high-risk trauma and general surgery patients. However,
these patients also pose significant challenges in providing
appropriate chemoprophylaxis. Patient characteristics put
them at high risk, and they may have relative
contraindications to chemoprophylaxis. Interruptions in
prophylaxis due to procedures or operations are common.
More than 70% initially present with a "herald bleed" that is
followed shortly by high-volume hemorrhage and death.
147
A review of more than 200 high-risk trauma and general
surgery patients found that only age older than 50 and
cumulative missed doses correlated with an increased risk of
VTE. Trauma (compared with general surgery), male sex, and
obesity were not independent risk factors in this study. Also,
epidural catheter use was not associated with increased risk
of VTE.
weeks) either while awaiting return of renal function or until
permanent access is obtained.
Items 12-13
11. A 63-year-old man presents with severe abdominal pain
and bloody diarrhea 2 months after a myocardial infarction
treated with coronary stent placement. His blood pressure is
98/60 mm Hg, and his heart rate is 115 beats per minute. An
abdominal CT scan with contrast is obtained (figure 12.1).
In an analysis of traumatic brain injury patients, interrupted
chemoprophylaxis had the highest odds ratio of predicting
VTE compared with other risk factors. Conversely, male sex
and BMI were not significant predictors.
11. A 42-year-old woman with stage HI chronic kidney
disease (glomerular filtration rate of 32 mL/min/1.73 m2; 90120 mL/min/1.73 m2) and a BMI of 32 was admitted to the
intensive care unit with acute oliguric renal failure 3 days
after a hysterectomy. She needs vascular access for
continuous renal replacement therapy. The most appropriate
option is
A.
B.
C.
D.
E.
temporary dialysis catheter, right internal jugular vein.
temporary dialysis catheter, left subclavian vein.
temporary dialysis catheter, right femoral vein.
tunneled right subclavian catheter.
tunneled left internal jugular catheter.
ANSWER:
A
Most postoperative or post-trauma patients who develop
acute kidney injury requiring renal replacement therapy will
recover kidney function and not need long-term dialysis.
However, this patient has pre-existing stage III chronic
kidney disease (glomerular filtration rate of 32 mL/min/1.73
m2; 90-120 mL/min/1.73 m2) and thus would be at very high
risk for eventually needing chronic long-term dialysis. Thus,
when planning her temporary, acute venous access, it is
important to be aware of her long-term needs and the
potential complications of short-term venous access.
Figure 12.1.
12. After fluid resuscitaion, the most Appropriate next step
in management is
A.
B.
C.
D.
E.
In general, the preferred vein for short-term dialysis access is
the right jugular vein because it gives a straight trajectory.
The left internal jugular can also be used, but due to its
circuitous route can have more issues with flow. The
subclavian veins should be avoided if possible due to
concerns of stenosis, especially in patients who are likely to
need permanent dialysis access in the arm (either fistula or
graft). Femoral access is a reasonable second choice if the
jugular is difficult or not available, but this access is
associated with higher infection rates (bacteremia, especially
in patients with high BMI) and the theoretical risk of iliac
vein stenosis complicating renal transplant if that should
happen. Tunneled catheters are usually not placed in the
acute, intensive care unit setting but are reserved for the
subacute phase when a patient needs long-term access (>3
diagnostic laparoscopy.
systemic anticoagulation.
flexible saigmoidoecopy.
upper endoscopy.
catheter-based papaverine infusion.
13. After initial management is commenced, the most
appropriate next step m management is
A.
B.
C.
D.
E.
observation.
repeat CT scan in 12 hours.
flexible sigmoidoscopy.
operative embolectomy.
mesenteric bypass.
ANSWERS:
148
B, D
This patient has a superior mesenteric artery (SMA) embolus,
most likely from a cardiac source (figure 12.2).
Items 14-17
Each lettered response may be selected once, more than once,
or not at all.
A.
B.
C.
D.
E.
Lifelong warfarin therapy
3 months apixaban therapy
4 to 6 weeks prophylactic dose fondaparinux
4 to 6 weeks rivaroxaban therapy
Observation
14. Popliteal vein thrombosis in a 52-year-old woman after
uncomplicated laparoscopic cholecystectomy
15. Isolated calf vein thrombosis in a healthy 36-year-old
man after ankle sprain.
16. A second episode of superficial femoral vein thrombosis
in a 62-year-old female breast cancer patient on tamoxifen
17. Superficial thrombophlebitis at the knee in a 56-year-old
perimenopausal woman
ANSWER:
B, E, A, C
Historical recommendations for the treatment of venous
thromboembolism (VTE) include treatment with parenteral
anticoagulation for at least 5 days and transition to
maintenance anticoagulation with warfarin. Current
guidelines recommend a minimum of 3 months of therapy. A
longer duration of treatment (e.g., 6 months) may be
associated with a decreased incidence of postthrombotic
syndrome. Although Factor Xa direct oral anticoagulants
(DOACs) eliminate the need for transitioning with parenteral
anticoagulation, the recommendations for duration of therapy
remain unchanged. Randomized controlled trials demonstrate
equivalent efficacy, and meta-analysis of phase III trials
shows DO AC use to be associated with a decreased
incidence of recurrent VTE and VTE mortality. For a patient
with a postoperative cholecystectomy, 3 months of apixaban
is adequate therapy.
Figure 12.2. Superior mesenteric artery embolus.
The CT scan demonstrates a large filling defect in the SMA
distal to the proximal branches. The initial treatment includes
fluid resuscitation and systemic anticoagulation to minimize
any future clot propagation. After these treatments have been
initiated, expeditious operative embolectomy with restoration
of the blood flow to the bowel is indicated.
An operative embolectomy is the most appropriate approach
to remove the embolus. Bypass of the SMA obstruction is
required in SMA thrombosis, but it is not indicated with
embolic disease. Catheter-based vasodilation with papaverine
may be appropriate in low-flow intestinal ischemia but has no
role in occlusive disease.
Isolated calf thrombosis associated with an injury in an
ambulatory patient should not receive anticoagulants. In a
randomized controlled study of 107 patients, the rate of
progression to proximal VTE was low at 3.7% and not
significantly different between patients treated with
anticoagulation and compression versus compression alone.
There were no VTE-associated deaths and no increased
incidence of venous recanalization with heparin use. For a 36year-old man with an ankle sprain, NSAID therapy for pain
control is sufficient treatment.
The time to restoration of perfusion is paramount. Although
assessment of the bowel viability is necessary after reestablishment of blood flow, neither endoscopy or
laparoscopy is indicated when there is ongoing ischemia.
Determination of the need for resection of bowel is typically
done at the completion of the embolectomy and may involve
a "second look" laparotomy at 12 to 24 hours after the initial
operation.
Recurrent VTE in patients with cancer can be difficult to
manage. For the patient with a history of breast cancer on
tamoxifen, there is an additional risk of VTE due to tamoxifen
in addition to the thrombotic risk accompanying her cancer
diagnosis. Current recommendations for treatment are for
149
lifelong anticoagulation unless there are contraindications to
pharmacotherapy such as active bleeding. Inferior vena cava
filter placement may be considered for these patients.
venous hypertension with development of venous collaterals
and eventual endothelial damage that predisposes patients to
acute or chronic venous thrombosis. Anatomic compression
may occur at numerous sites, and the attendant symptoms are
often expressed as venous hypertension distal to the
obstructed area. If untreated, venous compression can lead to
chronic, symptoms that limit the ability to work and quality
of life.
Approximately 60% of cases of superior vena cava syndrome
are caused by malignancy, whereas intravascular catheters
and implanted cardiac devices account for the majority of
benign cases. Face and neck swelling, headache, conjunctival
edema, dyspnea, and cough are the most common symptoms
(figure 18-22.1).
Recurrent VTE in patients with cancer can be difficult to
manage. For the patient with a history of breast cancer on
tamoxifen, there is an additional risk of VTE due to tamoxifen
in addition to the thrombotic risk accompanying her cancer
diagnosis. Current recommendations for treatment are for
lifelong anticoagulation unless there are contraindications to
pharmacotherapy such as active bleeding. Inferior vena cava
filter placement may be considered for these patients.
A patient with a superficial venous thrombosis does not have
a deep venous thrombosis. There are, however, increasing
amounts of data documenting that many of these patients will
have a concomitant VTE and an increased risk of future VTE.
American College of Chest Physicians guidelines from 2012
recommended treatment with fondaparinux for 45 days based
on the results of randomized clinical trials comparing
anticoagulation with nonsteroidal anti-inflammatory drugs
and observation. Reduction in the rate of recurrent superficial
venous thrombosis was observed in addition to a reduction in
future VTE.
Another venous problem is catheter-associated thrombus
which is not an uncommon finding in patients with lower
extremity central venous access (up to 30%). Current
recommendations are for prompt removal of the catheter and
treatment similar to other proximal VTE events with 3
months of anticoagulation. Other options for therapy include
the use of local thrombolytic therapy for more proximal
thrombosis when central venous access will continue to be
required.
Items 18-22
Each lettered response may be selected once, more than once,
or not at all.
A. Varicocele
B. Varicose veins below the knee
C. Unilateral arm pain and swelling
D. Iliofemoral deep vein thrombosis
E. Headache and conjunctival edema
Figure 18-22.1. Superior vena cava syndrome. Photographs of
patient showing reduction in swelling of the face, neck, and upper
extremities. (A) At initial presentation and (B) after treatment
(hospital day 8).
Treatment options depend on the etiology. Patients with
malignant lesions receive radiation with or without
chemotherapy. In benign cases, the indwelling device is
removed, and the patient is anticoagulated. A recent series of
patients with superior vena cava syndrome due to either
malignant or benign causes who underwent venoplasty and
stenting showed promising outcomes.
Chronic compression of the axillary-subclavian vein at the
level of the thoracic outlet is referred to as Paget-Schroetter
syndrome, also known as effort thrombosis or venous
thoracic outlet syndrome (figure 18-22.2).
18. Superior vena cava syndrome
19. Paget-Schroetter syndrome
20. Nutcracker syndrome
21. May-Thurner syndrome
22. Popliteal vein entrapment
ANSWERS:
E, C, A, D, B
Extrinsic compression of veins by adjacent arteries,
ligaments, muscles, or bones is most commonly seen in
young, healthy individuals. Extrinsic compression also can be
caused by adjacent neoplasms and metastatic lesions.
Regardless of etiology, venous compression can lead to -
Figure 18-22.2. Paget-Schroetter syndrome, also known as
effort thrombosis or venous thoracic outlet syndrome. Opened
subclavian vein demonstrating a first rib compression.
150
Compression is most commonly seen in the dominant arm of
active patients, and acute thrombosis is often provoked by
excessive overhead exercise. The site of compression is at the
costoclavicular triangle bordered by the first rib inferiorly, the
medial aspect of the clavicle superiorly, the subclavius
muscle and costoclavicular ligament medially, and the
insertion of the anterior scalene muscle laterally. Muscular or
ligamentous hypertrophy, bony abnormalities, or callus
formation from prior fractures may lead to narrowing of the
costoclavicular space. The most common symptoms are
unilateral arm pain and swelling, often accompanied by the
development of chest wall venous collaterals (figures 18-22.3
and 18-22.4).
The acute onset of symptoms usually heralds development of
axillosubclavian vein thrombus. Treatment involves lysis of
the thrombus, followed by surgical decompression of the
vein.
Compression of the left renal vein between the superior
mesenteric artery and the aorta is known as nutcracker
syndrome (figure 18-22.5).
Figure 18-22.5. Nutcracker syndrome
The syndrome is associated with left flank and abdominal
pain, often accompanied by gross or microscopic hematuria.
Because the left gonadal vein drains into the left renal vein,
men may develop left testicular pain and varicocele
formation. Women may present with pelvic pain,
dysmenorrhea, dysuria, and dyspareunia. Many treatment
options are available, including left renal vein transposition
and venous stenting. Patients with minimal symptoms may be
treated conservatively, as spontaneous regression has been
reported in some cases.
Compression of the left common iliac vein between the right
common iliac artery and sacral promontory or fifth lumbar
vertebra is known as May-Thumer syndrome (figures 18-22.6
and 18-22.7).
Figure 18-22.3. Patient with Paget-Schroetter syndrome
showing swelling and discoloration of the right arm and hand at rest.
Figure 18-22.4. Prominent superficial veins over the right upper
Figure.18-22.6. Illustration demonstrating the anatomic
arm and shoulder reflective of Urschel's sign.
compression seen in May-Thurner syndrome.
151
Left iliac vein compression is a common variant, and 50%
compression is reported in up to 25% of asymptomatic adults.
The syndrome
becomes clinically significant when compression results in
hemodynamic changes, such as flow reversal or development
of varicosities. Chronic compression leads to endothelial
damage that predisposes patients to thrombosis. The most
common presentation is acute ileofemoral deep vein
thrombosis manifest as sudden onset left leg swelling (figure
18-22.8).
Figure 18-22.7. A
Figure 18-22.8. May-Thurner syndrome and iliac arteriovenous
fistula in an elderly woman.
In the presence of thrombus, standard therapy is
anticoagulation and compression stockings. Currently, many
experts advocate catheter-directed thrombolysis of the
thrombus followed by placement of a self-expanding stent to
relieve the venous compression.
Figure 18-22.7. B. Diagnosis and treatment of May-Thurner
syndrome. (A) Infused CT scan shows compression of the left
common iliac vein by the right common iliac artery. The right
common iliac vain appear enlarged. (B) Left pelvic venogram shows
nearly complete obstruction of the left common iliac vein with
venous drainage of the left leg occurring through pelvic and
paraspinal collateral
Popliteal vein compression may occur in up to 25% of normal
adults and is considered to have no pathologic consequence
in asymptomatic individuals. The cause of compression is
usually an aberrant course of the medial head of the
gastrocnemius muscle; other causes include an adjacent
popliteal artery aneurysm, popliteal cyst, or popliteus muscle
sling (figures 18-22.9a and 18-22.9b).
152
Many patients have associated popliteal artery compression.
When the venous compression is hemodynamically
significant, affected patients may develop venous thrombosis
or varices below the knee (figure 18-22.10). Chronic
compression can lead to symptoms of chronic venous
insufficiency. Treatment depends on the degree of symptoms:
compression stockings for control of edema, anticoagulation
for deep vein thrombosis, and surgical decompression if both
artery and vein are involved.
23. A43-year-old woman underwent endovenous laser
therapy for treatment of symptomatic varicose veins in the
right leg. On routine postoperative ultrasound examination 1
week later, she has extension of a saphenous vein thrombus
to the saphenofemoral junction (SFJ). Treatment should
consist of
A.
B.
C.
D.
E.
Figure 18-22.9a. Classification of gastrocnemius medial head
anomaly. Type 1: an aberrant medial arterial course around normal
medial head of gastrocnemius muscle. Type 2: abnormal head of the
gastrocnemius muscle which is laterally inserted on the distal femur
with medial displacement of popliteal artery. Type 3: an aberrant
accessory slip from the medial head of the gastrocnemius muscle
wraps around the normally positioned popliteal artery and entraps it.
aspirin.
dopidogrel.
enoxaparin.
warfarin.
high ligation of the SFJ.
ANSWER:
A
Minimally invasive techniques using endovenous
radiofrequency or endovenous laser ablation have supplanted
high ligation and stripping as the preferred method of treating
symptomatic varicose veins due to superficial venous reflux.
Both techniques involve percutaneous introduction of a
radiofrequency or laser catheter into the great or small
saphenous vein. Radiofrequency or thermal energy is then
delivered throughout the vein treatment length, resulting in
endothelial destruction and thrombus formation. The ensuing
inflammatory reaction ultimately leads to fibrosis with vein
ablation. Venous ultrasound examination of the ipsilateral leg
is indicated in the early postoperative period to ensure that the
vein is ablated and that the thrombus has not extended into
the deep venous system.
As experience with these techniques increases, extension of
the thrombus from the great saphenous vein into the femoral
vein or from the small saphenous vein into the popliteal vein
is recognized more frequently. This so-called endothermal
heat-induced thrombosis (EHIT) occurs in 1.4 to 5% of
patients. Several EHIT classification schemes guide therapy.
The 4-level classification system first proposed by Kabnick
and colleagues provides a useful framework, as shown in
table 23.1
Figure 18-22.9b. Classification of gastrocnemius medial head
anomaly. Type 4: the popliteal artery located deep in the popliteus
muscle or beneath fibrous bands in the popliteal fossa. Type 5: any
form of entrapment that involves the popliteal artery and vein. Type
6: functional type normally positioned popliteal artery which is
entrapped by normally positioned gastrocnemius with hypertrophy.
153
Class
Thrombus Location
Treatment
1
Saphenofemoral or saphenopopliteal
junction
Aspirin
2
Extension into common femoral or
popliteal vein with cross-sectional
area <50%
Aspirin
3
Extension into common femoral or
popliteal vein with cross-sectional
area >50%
Systemic
anticoagulation
4
Total occlusion of the common
femoral or popliteal vein
Systemic
anticoagulation
C. argatroban.
D. bivalirudin.
E. a retrievable vena cava filter.
ANSWER:
C
Heparin-induced thrombocytopenia (HIT) should be
suspected in this patient with a history of heparin exposure
and a decreased platelet count This immune-mediated process
is a dangerous and potentially lethal complication of
unfractionated heparin (UH) and, less frequently, low
molecular weight heparin (LMWH). Heparin-induced
thrombocytopenia is caused by the formation of antibodies
against the heparin-platelet factor 4 (PF4) complex. The
antibody binds simultaneously to the heparin PF4 complex
and to the Fc platelet receptor, activating platelets and
promoting thrombin formation. Thrombosis is the most
severe consequence of heparin-induced thrombocytopenia;
venous thrombosis is more common than arterial thrombosis.
Table 23.1. Kabnick classification.
. Current treatment recommendations are based on EHIT
class. Close monitoring with serial ultrasound examinations
should be used in all patients diagnosed with EHIT. EHIT
classes 2,3, and 4 are deep vein thrombosis (DVT).
Two published studies used the following treatment protocol:
oral aspirin 81 mg or 325 mg daily for EHIT class 1 or 2 and
systemic anticoagulation for EHIT class 3 or 4. Systemic
anticoagulation was achieved until the thrombus retracted
caudal to the saphenofemoral or saphenopopliteal junction.
Using this protocol, 70 patients with EHIT were studied at a
single center. No participant with EHIT class 3 or 4
progressed, and 2 of 34 patients (6%) with grade 2 had
progression to grade 3 and required anticoagulation. In a
study of 201 limbs with EHIT in 194 patients, EHIT
resolution occurred in 78% of limbs within 4 weeks and
remained as class 1 in 13.5%. Although 4.5% showed
progression on serial ultrasound examinations, all
subsequently resolved within 4 weeks.
The essential sign of heparin-induced thrombocytopenia can
be an absolute drop in platelet count to less than
150,000/mm3 (150,000-400,000/m3) or a relative drop of
30% to 50% from baseline count. The thrombocytopenia
typically occurs 5 to 14 days after institution of heparin but
can occur sooner if the patient has had a previous heparin
exposure. Although thrombocytopenia due to other causes
may be associated with bleeding, patients with HIT are at
high risk for thrombotic complications.
The diagnosis of HIT requires laboratory confirmation, either
with functional platelet activation assays or immunoassays
such as the enzyme-linked immunosorbent assay. However,
if HIT is clinically suspected, the clinician should not wait for
positive test results to immediately stop heparin from any
source (UH, LMWH, heparin-bonded catheters, and heparin
flushes). Because the 30-day risk of subsequent thrombosis is
20 to 50%, alternative anticoagulation should be instituted.
Vena cava filters are not indicated because there are several
anticoagulants available. Published clinical guidelines from
the American College of Chest Physicians recommend
treating HIT with lepirudin, argatroban, or danaparoid. Of
these, argatroban is currently the only FDA-approved agent.
Lepirudin is no longer manufactured. Although bivalirudin is
not yet approved for use in HIT, it is effective in preventing
thrombotic complications. However, because bivalirudin is
renally excreted, it is relatively contraindicated in patients
with renal insufficiency. Warfarin should not be used in the
acute setting, because it causes a decrease in proteins C and
S, which can worsen the thrombotic risk. Warfarin can be
started at low doses (5 mg/day) when platelet counts increase
greater than 150,000/mm3, overlapping with a nonheparin
anticoagulant for at least 5 days. The use of direct oral
anticoagulants such as rivaroxaban, dabigatran, and apixaban
is under investigation, but these agents are not currently
recommended to treat HIT.
The patient presented here has class 1 EHIT. Treatment
should consist of daily aspirin and monitoring with serial
ultrasound examinations every 1 to 2 weeks. Clopidogrel is
not necessary unless the patient is allergic to aspirin. The
aspirin can be stopped when the thrombus retracts caudally.
In the rare case that the thrombus progresses to class 3,
anticoagulation should be instituted and continued until the
thrombus retracts caudally or for the full duration of DVT
treatment. Anticoagulation is not indicated now, nor is high
ligation of the saphenofemoral junction.
24. Two weeks after an aortofemoral bypass, a 67-year-old
man with chronic renal insufficiency presents with acute
swelling in his right leg. Duplex ultrasonography confirms
acute occlusive thrombus in the right femoral and popliteal
veins. He is started on unfractionated heparin. Twenty-four
hours later, his laboratory values are remarkable for a platelet
count of 57,000/mm3, which has dropped from a preoperative
value of 175,000/mm3 (150,000-400,000/mm3). The next
best step in treatment should be
A. continued unfractionated heparin.
B. change to low molecular weight heparin.
154