Peri-operative Assessments,
Pain, Fever, Oliguria and DVT
Prophylaxis
Peter E. Rice, MD
Surgical Fundamentals Session #4
ALGORITHMS
Pre-operative
Assessment
Fever
Oliguria
DVT Prophylaxis
Pain
Question:
What are the specific pre-operative laboratory tests
and/or evaluations that should be performed to confirm
or to rule out medical conditions that are likely to impact
a patient’s perioperative course?
> 3 billion dollars are spent each year on pre-op lab
evaluations- and > 60% of these are unnecessary
From the Anesthesiologists Point of View………….
Class
Physical Status
48 hr mortality
I
No systemic disease
0.07%
II
Mild systemic disease; no functional
limitation (obese, smoker, HTN)
0.24%
III
Severe, not incapacitating systemic
disease (CAD, CHF, COPD)
1.4%
IV
Incapacitating disease that is a
constant threat to life
7.5%
V
Moribund pt. not expected to survive
24 hrs regardless of surgery
8.1%
E
Suffix added to class
(emergency)
Doubles risk
ASA I
18-39 yr
No labs
Females Preg Test
40-59 yr
EKG
Females Preg Test
>60yo
SMA-7
CXR
EKG
Lab Tests <35 days acceptable w/o change in condition
CXR <6 months
EKG <2 months
Urine pregnancy on day of surgery
ASA II
Laboratory tests as required by
ASA I patients and tests as
indicated by the patient’s specific
disease states
CXR in all patients >20 pk-yr
smokers
ASA III
CBC
SMA-12
U/A
CXR
EKG
Upreg
Consult from
an appropriate
physician
Tests as indicated by the patient’s
specific disease state
Tests as Indicated by the Disease State…..
CNS
Seizure/stroke
Pulmonary
GI
Systems
Assessment
Renal
Heme/Onc
Medications
PFT’s, ABG,
Bronchodilators,
Steroids
Liver dz
CBC, Lytes
CBC,INR,PT,PTT
Tests as indicated by the patient’s specific disease state
And the risk of the planned procedure
The History and Physical will uncover the clinical risk of the patient
A Special Case…….
Low risk procedure
Hx/PE
?Cardiac DiseaseCAD,CHF,Arrhythmia,
CVA, PVD
Estimate
Clinical
Risk
High risk procedure
Exercise Stress
Dobutamine w/ Echo
Persantine Thallium
OR
One Additional Note
Perioperative Beta-Blocker Therapy



Patients who are receiving beta-blockers to
treat angina, arrhythmias, or hypertension
Patients undergoing vascular surgery who
are at high cardiac risk
Patients who are at increased
cardiovascular risk
advanced age
diabetes mellitus
renal insufficiency
Fever is a common event but
cannot be ignored
Two temperature elevations
>38.5 in a 24-hour period
Postoperative
Fever T>38.5
Early <48 hours
Late >48 hours
Both evaluations begin with History and Physical Exam
•The cause of most postoperative fevers will be elucidated
by the history and physical
•Check the comorbidities- transfusion, meds, malignancy,
FB, diabetes
•Always check the operative site
Early <48 hours
Physical exam
Wind
Wound
Water
Walk
Wonder Drugs
cellulitis
Wound
drainage
Respiratory
CXR
IV sites
Late >48 hours
Physical
Examination
GU
?AIE
?infected
UA /CX
Intra-abdominal
Extremity swelling
CT Scan
Duplex
Oliguria
Acute oliguria is the excretion of <400cc of urine per day, and is often the earliest
sign of impaired renal function
Oliguria
Classification of
Acute Renal
Failure
Prerenal(50%-90% of total cases)
Volume depletion
Dehydration
Hemorrhage
Fluid redistribution
Cardfiac Failure
Systemic vasodilatation
Renovascular obstructive disease
Renal Parenchymal(10-30%)
ATN
Ischemia
Nephrotoxins
Glomerulonephritis
Vasculitides
Interstitial nephritis
Postrenal(1%-15% of total cases)
Obstructive uropathy
Renal pelvis and ureters
Bladder and urethra
Extravasation
Patient presents
with signs of oliguria
urine output<.5cc/
kg/hr
68yo male s/p LAR with loop ileostomy T
37 P 110 BP 110/75 R12 UO 14cc in the
last hour
Clinical assessment:
Vitals
Check the Chart
Physical Exam
Urinary tract
obstruction
Urine output does not resolve
Re-evaluate
Administer second IV fluid challenge
?CVP
Calculate FENa
Urine and Plasma electrolytes
Administer I.V. fluid
challenge (~10%
circulating volume)
isotonic crystalloid
? blood
Prerenal dysfunction
(UNa<20mEq/L orFENa<1)
Urine output
improves- continue
to monitor
Expand intravascular volume
Monitor CVP,PAWP,
?acute renal arterial problems
?abdominal compartment
syndrome
?CHF
?sepsis
Renal parenchymal
dysfunction (UNa>40
mEq/L or FENa>3
Stop nephrotoxic drugs
if possible
Avoid contrast agents
Consider loop diuretics
Renal dysfunction
continues or
progresses
Renal Function
returns to normal
Continue
monitoring. Avoid
hypovolemia and
use of nephrotoxic
agents
Adjust medications
and fluids
?Renal replacement
therapy CVVH
Renal deterioration
stops or slows
Chronic renal failure
ensues
Fe NA = Urine [Na] / Plasma [Na]
x100
Urine [Cr] / Plasma [Na]
FeNa < 1% prerenal
FeNa > 2% renal (ATN)
Urinary sodium (meqL)
<20 prerenal
>40 renal
DVT
Venous Thromboembolism
Pulmonary
Embolus
National Body Position Statements
o Leapfrog1:
• PE is “the most common preventable cause of hospital
death in the United States”
• Agency for Healthcare Research and Quality (AHRQ)2:
Thromboprophylaxis is the number 1 patient safety practice
• American Public Health Association (APHA)3:
“The disconnect between evidence and execution as it
relates to DVT prevention amounts to a public health crisis.”
1.
2.
3.
The Leapfrog Group Hospital Quality and Safety Survey. Available at:
www.leapfrog.medstat.com/pdf/Final/doc
Shojania KG, et al. Making Healthcare Safer: A Critical Analysis of Patient Safety Practices. AHRQ,
2001. Available at: www.ahrq.gov/clinic/ptsafety/
White Paper. Deep-vein thrombosis: Advancing awareness to protect patient lives. 2003. Available at:
www.alpha.org/ppp/DVT_White_Paper.pdf
Rationale for DVT Prophylaxis



High Prevalence of DVT
Adverse Consequences of DVT
Efficacy and effectiveness of
thromboprophylaxis




Highly efficacious in prevention of DVT
Highly efficacious in prevention of symptomatic DVT
and fatal PE
DVT prevention prevents PE
Cost effectiveness has been demonstrated
Absolute Risk of DVT in
Hospitalized Patients
Patient Group
DVT Prevalence, %
Medical patients
10-20
General surgery
15-40
Major GYN surgery
15-40
Major GU surgery
15-40
Neurosurgery
15-40
Stroke
20-50
Hip or Knee surgery
40-60
Major Trauma
40-80
Spinal Cord Injury
60-80
Critical Care patients
10-80
Thromboprophylaxis Reduces
DVT Events

Pulmonary Embolus is the most common
preventable cause of hospital death
Risk Factors for DVT


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

Surgery
Trauma
Immobility, paresis
Malignancy
Cancer therapy
Previous VTE
Increasing age
Pregnancy and postpartum
Estrogen-containing oral
contraception or HRT
Selective estrogen receptor
modulators
Acute medical illness




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

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Heart or respiratory failure
Inflammatory bowel disease
Nephrotic syndrome
Myeloproliferative disorders
Paroxysmal nocturnal
hemoglobinuria
Obesity
Smoking
Varicose veins
Central venous
catheterization
Inherited or acquired
thrombophilia
Methods of Prophylaxis

Mechanical Methods




Studies




Graduated Compression Stockings
Intermittent Pneumatic Compression device
Venous foot pump
Not blinded
High rate of false negative scans
Compliance in true practice – poor
Acceptable option


High risk for bleeding
Adjunct to anticoagulant prophylaxis

Improves efficacy when used in combination with anticoagulant
prophylaxis
Anticoagulants



Most widely used and studied prophylaxis
Before 1987, only heparin and warfarin were available
Now,
4 low molecular weight heparins
1 Factor Xa inhibitor
3 direct thrombin inhibitors
1 coumarin derivative
Unfractionated Heparin
Potentiates inactivation of
activated enzymes of
clotting cascade, via
binding to antithrombin III
Effective in preventing DVT
in low and moderate risk
patients
Does not increase risk of
hemorrhage
Low Molecular Weight Heparin
Higher bioavailability; stable and
predictable antithrombotic
activity
Can be administered once-daily
Lower risk of thrombocytopenia
More effective for high risk
prophylaxis than heparin
General Surgery

46 RCT Low Dose Unfractionated Heparin
v. placebo or no proph.

Reduced
DVT 22 to 9%
 Symptomatic PE 2 to 1.3%
 Fatal PE 3 to .8%


Meta-analysis

No increase in wound hematoma or bleeding
General Surgery

LMWH (Lovenox)
 Meta-analysis
(Douketis Arch Intern Med
2002)


70 % reduction DVT v. no prophylaxis
Nine meta-analysis and systematic reviews
No difference in DVT LMWH and UFH
 Some trials fewer hematomas and bleeding
complications with LMWH
 No difference in total mortality, fatal PE between
LDUH 5000 units TID and LMWH

General Surgery

Low Risk
Minor Surgery (hernia repair, outpatient
surgery)
 < 40 years of age
 No additional risk factors


Risk
DVT
 PE


Calf – 2%
Clinical – 0.2%
Proximal – 0.4%
Fatal - <0.01%
Prevention Strategies

No specific prophylaxis; early mobilization
General Surgery

Moderate Risk

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Risk

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
Minor Surgery with additional risk factors
Age 40-60 with no risk factors
Major surgery, < 40 with no risk factors
DVT
PE
Calf - 10-20%
Clinical - 1-2%
Proximal - 2-4%
Fatal - 0.1-0.4 %
Prevention Strategies




LDUH (5,000 units q 12 hours, start 1-2 hrs pre-op)
LMWH ( 30mg daily)
Graduated Compression Stockings
Intermittent Pneumatic Compression Devices
General Surgery

High Risk

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
Risks



Non-major surgery in age > 60 yr. or have additional
risk factors
Major Surgery > 40 or have additional risk factors
DVT
PE
Calf – 20-40%
Clinical – 2-4 %
Prevention Strategies


LDUH (5,000 U q 8 hours)
LMWH ( 30mg q 12h)
Proximal – 4-8%
Fatal – 0.4-1.0%
General Surgery

Highest Risk

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Risk

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Surgery in patients with multiple risk factors
DVT Calf – 40-80% Proximal – 10-20%
PE Clinical – 4-10%
Fatal - 0.2 - 5%
Prevention Strategies



LDUH ( 5,000 q 8 hours)
or
LMWH ( 30mg q12h)
with
GCS and/or IPC
General Surgery

Special Considerations
High Risk of Bleeding
Properly fitted GCS and/or IPC
Major Cancer Surgery
Post hospital discharge prophylaxis with LMWH for
2-3 weeks
Prolonged prophylaxis in abdominal and pelvic cancer
reduced DVT 12 to 5%
Bergqvist NEJM 2002
Vascular Surgery

Risk

Aortic Surgery - DVT – 0.9 - 12 %
prophylaxis – 41%

Femorodistal – DVT – 0.7 – 9%
prophylaxis – 18%

No routine prophylaxis in patients without risk
factors

LDUH or LMWH in patients with risk factors
No
No
Recommendations in Laparoscopy

European Association for Endoscopic Surgery


SAGES

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Intraoperative IPC for all prolonged laparoscopic
procedures
Same thromboprophylaxis options with
laparoscopic procedures as for the equivalent
open surgical procedures
ACCP

No risk factors – aggressive early mobilization
With risk factors – LDUH, LMWH, IPC or GCS
Major Trauma


Highest Risk of all Hospitalized Patients
Risk – without Rx exceeds 50%

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
Calf – 40-80%
Clinical – 4-10%
Proximal – 10-20%
Fatal - 0.2 - 5%
Risk with routine thromboprophylaxis


DVT
PE
DVT
Calf – 27%
Proximal – 7%
Increased Risk Factors

Spinal Cord injury, lower extremity or pelvic Fx, need for
surgery, increasing age, femoral venous line insertion or
major venous repair, prolonged immobility, prolonged
ventilatory support and longer duration of hospital stay, +/ISS
Trauma Recommendations

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All patients with at least one risk factor
receive thromboprophylaxis
LMWH as soon as considered ‘safe’
If LMWH delayed – Boots
Continued thromboprophylaxis until mobility
adequate
Duplex ultrasound screening – high risk and
suboptimal prophylaxis or no prophylaxis
Pain
An unpleasant sensory and emotional
experience associated with actual or
potential tissue damage, or described
in terms of such damage.
“Pain is whatever the
experiencing person says it
is and exists whenever
he/she says it does.”
Classes of drugs

Opioid analgesics

Nonsteroidal anti-inflammatory drugs
(NSAIDS) (Aspirin, Motrin, Toradol)
Opioid Analgesics
Schedules of Controlled
Narcotics

Schedule I: Unacceptable potential for
abuse: Heroin, Cocaine, LSD

Schedule II: High potential for abuse and
dependence: opioids, amphetamines

Schedule III: Intermediate potential for
abuse: codeine+ acetaminophen,
hydrocodone + acetaminophen
Schedules of Controlled
Narcotics

Schedule IV: Less abuse potential than
schedule III, minimal dependence:
lorazepam alprazolam, diazepam

Schedule V: minimal abuse potential:
codiene cough syrup, lomotil
Action
Binds to opiate receptors in the central
nervous system.
Alters the perception of and response to
painful stimuli
Produces generalized CNS depression
CNS side effects of opioids
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Respiratory depression
Hypotension, orthostatic hypotension
Constipation, nausea,vomiting
Urinary retention
Confusion
Rash
Contraindications &
Precautions

Contraindications:


Hypersensitivity
Precautions:
Elderly
 Respiratory diseases
 Head trauma
 Liver or kidney disease
 Opioid addiction

Morphine



Prototype opioid analgesic
Equianalgesic doses of opioids
Indications:
Severe pain
 Pulmonary edema
 Pain associated with myocardial infarction.

Morphine administration routes

Many preparations & routes:
Oral: tablets, extended release (MS Contin)
 elixir (Roxanol)
 Sublingual tablets: 10 mg, rapidly absorbed
 IM
 IV, PCA
 Epidural

Postoperative pain

Regular & frequent dosing intervals in
early postop period, then PRN
PCA, Epidural, IV
 Opioid + NSAID
 Switch to oral dosing when taking po


Medicate prior to anticipated pain
Ambulation & physical therapy
 Dressing changes

PCA: patient controlled
analgesia

Self-administration of IV analgesic
 Very effective
 Prevents delays
 Reduces patient anxiety
PCA dosing

Example



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Morphine PCA
30mg/30ml
Basal rate 1 mg/hr
Demand dose 1-2 mg
Lockout 6-8 minutes
4 Hour Max
QUESTIONS ?