1. Descrihe the murmurs heard. and specify
the stethoscope location where they are best
heard, if the patient has aortic stenosis. If the
patient has aortic regurgitation.
Aortic stenosis is recognized by its characte rist ic systolic murmur. best
heard in the second right intercostal space (over the aortic arch) with
transmission into the neck. Aortic regurgitation is recognized by its diastolic
murmur. best heard along the left sternal border. [Hines. Stoelting's
Co-existing. 5e. 2008 pp37, 39]
2. 'Name the organs in the vessel rich group
(VRG). What percent of cardiac output goes
to each of these organs?
The brain, kidney. liver, lungs , heart. diges tive tract. and endocrine tissues
are organs of the vessel rich group (VRG). These are the wel/perfl/
sed organs. 25% of the ca rdiac output goes to the liver; 4-5% (225
mLim in) to the heart; 15% to the brain; 20% to the kidneys; and 100% to
the lungs. IGuyton. TMP. li e. 2006 pp l96t; Stoelt ing, PPAP. 4e. 2006
pp3 1; Morgan, et al.. C/ill. Allesth .. 4e. 2006 pp l581
3. In words. descr ibe where isovolumelric
relaxation occurs on the left ventr icular
pressure-volume loop
Isovolumctric relaxa tion occurs from closure of the aortic valve to opening
of the mitral valve on the left vent ricular pressure-volume loop. [Nagel·
hout & Zaglan iczny. NA. 3e. 2005 pp4361
4. ln words. describe where isovolurnetric
contraction occurs on the left ven tricular
pressure-volume loop.
Isovolumetric co ntraction occurs from closure of the mitral va lve to openiug
of the (lortic valve on the left ventricular pressure-volume loop. [Na·
gelhout & Zaglaniczny. NA . 3e. 2005 pp4361
5. -What nerves carry the afferent and efferent
signals of the Bainbridge reflex? What
does the Bainbridge reflex help prevent?
When the great veins and right atrium are stretched by increased vascular
volume. stretch receptors send afferent signals to the medulla via the
vagus nerve. The medulla then transmits efferent signals via the sympathetic
nerves to increase heart rate (by as much as 75%) and myocardial co ntractility. The
Bainbridge reflex helps prevent damming up of blood in
veins, the atria, and the pulmonary circulat ion.IGuyton. TMP. lI e. 2006
pp2121
6. @)What percentage of cardiac output is
delivered to the highly-perfused organs
(heart, lungs, brain, kidneys, and liver)?
Approximately 75% of resting cardiac output is delivered to the vesselrich
organs. although they constitute only 10% of total body mass. [Stoelting
7. @)Describe myocardial preconditioning.
Myocardial preconditioning is a short-term rapid adaptation to brief
ischemia such that during a subsequent, more severe ischemic insult.
myocardial necrosis is delayed. The infarct-delaying properties of ischemic
preconditioning have been observed in all species studied. Five minutes
of ischemia is sufficient to initiate preconditioning, and the protective
period lasts for I to 2 hours. [Stoelting. PPAP. 4e. 2006 ppl71; Cote,
8. @)Describe the cellular mechanisms mediating
myocardial preconditioning
Pharmacological activation of adenosine receptors (particularly al and a2
subtypes) initiates preconditioning via intracellular signal transduction
mechanisms involving protein kinase C and adenosine triphosphate (ATP)-dependent
potassium channels (KATP). Other factors involved
include including the sodium: hydrogen exchanger, inhibitory G proteins,
and tyrosine kinase. [Stoelting. PPAP. 4e. 2006 pp171; Cote. PAle. 4'h
2009 pp343; Barash. Clin. Alles .. 6'h 2009 pp430]
9. @)Whatanestheticagentscan trigger or
modulate the myocardial preconditioning
response? What anesthetic agent can antagonize the effect?
The vo lat ile anesthetics mimic ischemic preconditioning and trigger a
similar cascade of intracellular events resulting in myocardial protection
LIlat las ts beyond the elimination of the anesthetic. Adenosine or opioid
agonists delivered into the coronary circulation may also mimic preconditioning.
Ketamine antagonizes the protective effect of preconditioning
and thus should be used with caution in the patient at risk for myocardial
infarction in the perioperative period. [Stoelting. PPAP. 4e. 2006 pp171;
Cote. PAle. 4,h 2009 pp343; Barash. Clin. Anes .. 6'h 2009 pp430]
10. What monitoring is indicated for managing
the patient with a history of congestive
heart failure secondary to diastolic dysfunction?
The use of invasive monitoring such as central venous pressure (CVP) or
pulmonary artery catheter (PAC) may be indicated in managing the patient
with a history of congestive heart failure secondary to diastolic dysfunction.
[Miller & Stoelting. Basics. Se. 2007 ppS26
11. List 4 compensatory responses in the
patient with cardiac failure.?
Four major compensatory mechanisms participating in the response to
cardiac failure are (1) increased left ventricular preload, (2) increased
sympathetic tone, (3) activation o/the renin-angiotensin-aldosterone
system, (4) release of AVP (arginine vasopressin, antidiuretic hormone),
and (5) ventricular hypertrophy. These mechanisms initially compensate
for cardiac failure, but with increasing severity of the disease, they may
actually contribute to the cardiac impairment. [Morgan, et al., Clin.
Anesth .. 4e. 2006 pp433-434; Hines, Stoelting's Co-existing. Se. 2008
12. What is the principal hemodynamic
alteration with cardiac tamponade? What is
Becks triad?
The principal hemodynamic feature of cardiac tamponade is a decrease in
cardiac output due to a reduced stroke volume, secondary to an increased
central venous pressure and thus reduced venous return to the heart. The
diagnosis of postoperative cardiac tamponade should be considered
whenever hemodynamic deterioration is encountered, particularly when
reductions in CO or BP or both are not readily resolved by conventional
management. Becks triad is the constellation of hypotension. jugular
venous distension, and distant, muffled heart sounds. [Morgan, Mikhail,
and Murray, Clin. AnesthesioL, 41h ed., 2006, pS26; Yao & Artusio, Yao &
Artusio's Anesthesiology: Problem-Oriented Patient Management, Sih ed.,
13. What class of drugs may be given preoperatively
to the untreated. asymptomatic.
mildly hypertensive patient to attenuate
tachycardia with tracheal intubation and tachycardia and emergence?
A small oral dose of a beta-adrenergic antagonist, such as labetalol (Normodyne,
Trandate), atenolol (Tenormin), or oxprenolol (Trasicor) given
preoperatively to the asymptomatic, mildly hypertensive patient may
effectively attenuate tachycardia with tracheal intubation or upon emergence.
[Yao & Arlusio, Yao & Artllsio's Allesthesiology: Problem-Oriented
14. What muscle ac ts as a barrier to reg urgitation
in the conscious subject?
In the awake subject, the cricopharyngeus muscle is the primary muscular
barrier to regurgit at ion.INagelhout & Zaglaniczny, NA, 3rd ed., 2004
15. Laryngospasm is caused by stimulation of which nerve?
Stimulation of the superior laryngeal nerves may cause laryngospasm
16. Wesl's zones of the lung describe alveolar
perfusion based on the relationship of three
pressures: alveolar press ure (P,o\.). arterial
press ure (PP .... ) and venous pressure (Ppv).
Which region shows the greatest increase in
blood flow over the distance of the zone?
West zone 2 shows the greatest increase in blood now over the distance of
the lone; blood now is zero at the nondependent start of zone 2 and increases
with dependency over the distance of zone 2. Reminder: zone 2 is
the "waterfall zone" of intermitte1lt blood flow. where PPA> P A> PPV. IWest,
P"/",. Physiol .. 8e. 2008 pp43-44; Barash, Clinical Anes .. 5e. 2006 pp82 If;
17. , IIWest's zones of the lung describe alveolar
perfusion based on the relationship of three pressures: alveolar pressure (PA), arterial
blood now,
and venous pressure (Ppv). Which region has the maximal blood flow of any zone?
West zone 3 possesses the maximal pulmonary blood now of any zone
(region). Reminder: zone 3 is the "distension zone" with continuous
pressures: alveolar pressure (PA), arterial blood now, where PPA> Pllv> P A.
18. @)How does marked right-to-Ieft intrapulmonary
shunting manifest on radiographs?
Marked right-to-left intrapulmonary shunting (shunt flow> 15%) is associated
with radiographically discernable findings such as pulmonary
atelectasis, parenchymal inftltrates, or a large pneumothorax. [Morgan
19. lWhat happens to pulmonary blood flow in zone 4 of the lung?
Lung regions where PI'A>P1SF> Ppv> PA are termed zone 4 regions. Blood
flow in zone 4 is reduced by gravitational compression of the lung parenchyma
or by illterstitial edema formatioll. [Stoelting, PPAP. 4e. 2006
pp746; Hagberg, Bellllmofs Airway Mallagemellt. 2e. 2007 pp 116-117[
20. What is the carbon dioxide content (in
vol %) in room air? What is the partial pressure
of CO2 in room air (assume standard pressure)?
The carbon dioxide content of room air is 0.03%. According to Daltons
law, the part ial pressure 0(C02 in room air is 0.23 mm Hg. [AuthorsJ
21. What are pulmonary J-receptors?
Juxtapulmonary-capillary receptors U receptors) are located in the walls of
the pulmonary capillaries or in the interstitium, hence the name. J receptors
appear to be stimulated by pulmonary vascular congestion or an increase in pulmonary
interstitial fluid volume. leading to tachypnea. The
J receptors may also be responsible for the dyspnea encountered during
pulmonary vascular congestion and edema secondary to left ventricular
failure. [Levitzky. Pulm. Physiol .. 7e. 2007 ppI99-200; Lomb & Nun
22. lWhich nerve fiber type innervates pulmonary J receptors?
C·fibers lie in close relationship to the pulmonary microcirculation and
appear to in nervate the pulmonary J receptors. The afferent pathway from
.vagalll"ves, [Levilzky. Pulm. Pilysio/.. 7e. 2007 ppI99-200; Lomb &
23. KLung auscultation reveals basilar crackles
and chest radiographs exhibit "whited-out"
areas; what is your diagnosis?
The detection of basilar crackles on auscultation is the traditional hallmark
of early pulmonary edema. A "butterfly" appearance or "whitedoue'
areas on chest radiographs support the diagnosis of pulmonary edema
24. What airway event may lead to the development
of negative pressure pulmonary
edema (NPPE)? Describe the mechanism of NPPE formation
Acute airway obstruction such as laryngospasm can lead to negativepressure
pulmonary edema. As the patient breathes against a closed glottis
during laryngospasm, a more negative (greater magnitude) intrathoracic
pressure is created. The increased intrathoracic pressure is transmitted
to interstitial tissue, creating a greater hydrostatic pressure gradient
between the interstitial space and the pulmonary circulation. The increased
hydrostatic pressure gradient from blood to tissue will promote
movement of fluid from the blood to the tissue and into the alveoli. [Stoelting
& Miller, Basics, 5th ed., 2007, p470; Nagelhout & Zaglaniczny, NA,
25. ~How is negative-pressure pulmonary
edema (NPPE) treated?
Negative-pressure pulm~nary edema (NPPE) is treated by positive endexpiratory
pressure (PEEP) ventilation. Diuretics and fluid restrictions are
not required as the condition is self-correcting. [Yao & Artusio, Yao &
Artusio's Anesthesiology: Problem-Oriented Patient Management, 5th e
26. What is the primary mechanism ofhypoxemia
in the patient with chronic obstructive
pulmonary disease (COPD
The primary mechanism of hypoxemia in obstructive pulmonary disease
is regional mismatch o/ventilation and perfusion (V/Q mismatch). [Dunn,
et al., Clin. Anes. Procedures of the Massachusetts General Hospital, 71h
27. @What membrane ion channels playa role
in cell repoiarization
The necessary actor in causing both depolarization and repolarization of
the nerve membrane during the action potential is the voltage-gated
sodium channel. A voltage-ga ted potassium channel also plays an important
role itl increasing the rapidity of repoiarization of the membrane.
Repolarization begins with the clos ing of the voltage-ga ted sodium channels,
followed by opening of the voltage-gated potassium channels. During
early repolarization. the sodium channels are in the closed. inactive
co nformation causing the (eillO be absolutely refractory to stimulus.
During the latter stages of repoiarization, the voltage-gated sodium channels
have returned to the closed. res ting conformation. and the cell is
relatively refractory to stimulus. [Guyton, TMP. li e. 2006 pp62; Nagelhout
28. v'Which neurotransmitter is the most
common exci tatory neurotransmitter in the
ce ntral nervous system (eNS)?
Glutamate is the most common exci tatory neurotransmitter in the central
nervous sys tem (CNS). Glutamate is an excitatory amino ac id neurotransmiller.
[Stoelting, PPAP. 4e. 2006 pp674; Miller, Allestilesia. 6e.
29. List three (3) common ionotrop ic glutamate
receptors in the central nervous sys tem
(eNS). Which electrolytes (ions) pass
through these receptors upon activation?
The three ligand-gated ionotropic glutamate receptors of the eNS are: (I)
N-mcthyl-D-aspartate = NMDA, (2) AMPA, and (3) kaina te. When the
ligand glutamate binds to these iono tropic recepto rs, a transmembrane,
cation-selective channel opens. pe rmitting influx of Nat and Cah and
effiux of K+. Sodium is the main ion permeating the channel, leading to
membrane depolarization. [Stoelting, PPAP. 4e. 2006 pp674; Guyton
30. What enzyme catalyzes the synthesis of
acetylcholine (ACh)? Where does ACh synthesis occur?
Synthesis of acetylcholine (ACh) occurs in the cytoplasm of nerve terminals.
Choline acetyltransferase (ChAT) catalyzes the formation of ACh
from the precursors (substrates) choline and Acetyl-CoA (from mitochondria).
[Stoelting, PPAP. 4e. 2006 pp701; Guyton, TMP. lie. 2006
31. K'The gamma amino butyric ac id type A
(GABA,) recep tor has at least 7 ligand binding
sites. Identify the 7 ligand binding sites
the GABA ... receptor posses
The 7 ligand binding si tes on the GABA, receptor are for: (1) GABA, (2)
barbiturates, (3) benzodiazepines, (4) propofoJ, (5) steroids, (6) anesthetie/
alcohol. and (7) picrotoxin. Notice that 5 of th e 7 sites involve anesthetic
agents!
32. vWhat is the conus med ullaris? What is the filum terminale?
The conus medullaris is the blunt, tapering tip of the spinal co rd. The pia
alone continues from the conus medullaris and after piercing the dural
sac, continues wi th a covering of dura to the coccyx, forming the filum
terminalis. The fi lum terminalis is comprised of the pia and dura malere.
[Ellis & Feldman, Allatomy for Allaestlretists. Be. 2004 pp 120; Authorsl
33. N'Desc ribe the anatomy of the hypogastric
plexus.
The pelvic viscera in men and women-the urogenital organs. the colon.
and the rectum-are supplied by afferent fibers from the lumbar sympathetic
chain. The superior hypogastric plexus is a retroperitoneal structure
that is fo rmed by confluence of the bilateral lumbar sympathetic chaitls; it
is siluated between the bodies of the Ls and S I vertebrae. The pelvic pain
caused by either inflammatory diseases or cancer can be relieved by inter·
ruption of bilateral sympathetic pathways. which can be achieved with a
superior hypogastric plexus block.
34. Where do preganglionic parasympathetic
nerves originate?
Preganglionic parasympathetic nerves arise from nuclei of cranial nerves
III, VII, IX and X in the brainstem and also from sacral segments 2-4 (S2S4) of the spinal cord. Owing to these origins, the parasympathetic system
is also known as the craniosacral division.
35. @List the six (6) orbital muscles, their runction,
and their motor innervation
Superior rectus: Supraduction or orbit ("look up"); innervation by eN III
(oculomotor)
Inrerior rectus: Inrrad uction or orbit ("Iook down"); innervation by eN III
- oculomotor
Medial rectus: Adduction or orbit ('look inward'); innervation by eN 111 oculomotor
Lateral rectus: Abduction or orbit ('look outward"); innervation by eN VI
- abducens
Superior oblique: Intorsion, depression or orbit ("look in and down");
innervation by eN IV - trochlear
Inferior oblique: Extorsion, elevation or orbit ("look out and up"); inner·
vat ion by eN III . oculomotor
[Nagelhout, NA . 4''- 2009 pp943; AuthorsJ
36. IWhich cranial nerve provides sensory
innervation to the face? List the three
branches of this nerve,
The trigeminal nerve (eN V) provides sensory innervation to the face. The trige minal
nerve has three branches: the ophthalmic. the maxillary. and the mandibular.
The ophthalmic and maxillary are pu rely sensory. whereas the mandibular
nerve is a mixed (motor & sensory) nerve.IBarash.
37. Describe the motor and sensory functions
of the mandibular branch of the trigeminal
nerve (eN V).
The anterior branch of the mandibular nerve provides motor innervation to the
muscles of masticat ion (chewing, "moves the mandible"). The posterior branch of
the mandibular nerve provides sensory innervation to the lower teeth and gums
("feels the mandible, in side and out"). lila rash, Clin. Anes., Sib ed., 2006. pp72l 722; Morgan, Mikhail, and Murray, Clill. Anesthesia/., 41h ed., 2006, pp37S-376;
38. Describe the sensory inn ervation of the
racial nerve (eN VII).
The racial nerve (eN VII) provides special sensory innervation to the
anterior two-thirds of the tongue (taste) and general sensory innervation
to the tympanic membrane. external auditory meatus, soft palate, and
part of the pharyn x. IMorgan. Mikhail
39. N'ln addition to hyperplastic lymphoid
tissue and a large tongue (~ difficult airway),
what other finding may be coexistent
with sarcoidosis?
Polyneuropathy is a frequent finding in the patient with sarcoidosis.
Unilateral or bilateral facial nerve paralysis may occur due to sarcoid
involvement of the facial nerve as it courses over the parotid gland. Diabetes
inSipidus (DI, both neurogenic and nephrogenic forms) may also
occur with sarcoidosis. [Stoelting & Dierdorf
40. vIdentify the anesthetic agents that are
absolutely contraindicated in the patient
with a family history of malignant hyperthermia
All volatile (potent) inhalational agents and succinylcholine are absolutely
contraindicated in patients with malignant hyperthermia
41. What are the clinical mani festations of
myotoniC dystrophy (Ste inert's disease)?
Myotonia dys trophy (Steinert's disease. myotonic atrophica) is a multisystem
disease that usually manifests as facial weakness (expressionless
facies). wasting and weakn ess of the sternocleidomastoid muscles. ptosis,
dysarthria, dys phagia, and inability to relax the hand grip (myotonia).
Frontal balding, catarac ts. and testicular atrophy in males form a frequently
recog nized triad of characteristics. INage1hout, N
42. ®Identify tl~ e genetic pattern of inheritance
for myotonic dystrophy and describe the
pathophysiology of this group of degenerative diseases
MyotoniC dystrophy (MD) is inherited as an au tosomal dominant trait
and usually manifests in the second or third decade oflife. Myotonic
dystrophies are charac terized by persistent contracture (myoton ia) after
voluntary contracture of skeletal muscle or following electrical stimulation.
Electromyographic fir/dings are diagnostic and are characterized by
prolonged discharges or repetitive ac tion potentials. Skeletal muscle
resting membrane potentials arc also lowered (less polarized) in patients
with MD. The inability of the skeletal muscle to relax after voluntary
contraction or stimulation res ults from abnormal calcium metabolismATPdriven pumps fail to return calcium to the sarcoplasmic reticulum
(SR) thus the unsequestcred ca lcium remains available to produced sustained
skeletal muscle contraction. INagelhout, NA. 4''- 2009 pp795-796
43. @lWhat four anesthet ic concerns should you
have for the patient with myotoniC dys tro phy?
Preoperative evaluation and management of anes thesia in patients with
myotonic dystrophy must consider the likelihood of (I) cardiomyopa thy.
(2) respiratory muscle weakness and sensitivity to res pirato ry depressa
nts, (3) vulnerability to asp irat ion of gas tric contents, and (4) potential
for abnormal responses to anesthetic drugs. INagelhout, NA . 4th. 2009
pp796; Hines, Stoelting' Co-existing. 5e. 2008 pp4491
44. Should succinylcholine be used in the
anesthetic management of the patient with
myotonic dystrophy?
Succinylcholine should not be used in the patient with myotonic dystrophy
because succinylcholine can produce intense generalized myotonic
contracture that makes ventilation or intubation difficult or impossible.
[Nagelhout, NA. 4th. 2009 pp796; Hines, Stoelting's Co-existing. Se. 2008
45. @)What is the medical management of the
patient with myotonic dystrophy?
Treatment of myotonic dystrophy is symptomatic and may include the
use of phenytoin, quinine, and procainamide. These agents delay the
return of membrane excitation by blocking rapid sodium (Na+) influx into
muscles. Quinine and procainamide should be used with caution as they
may worsen cardiac conduction abnormalities (prolonged P-R interval).
[Nagelhout, NA. 4th. 2009 pp796; Hines, Stoelting's Co-existing
46. ft'Myasthenia gravis is characterized by
what symptoms? What is the cause of these
symptoms?
Myasthenia gravis is characterized by weakness and easy fatigability of
skeletal muscles. The weakness can be asymmetric, confined to one group
of muscles, or generalized. Easy fatigability of skeletal muscle in myasthenia
gravis is caused by autoimmune destruction of nicotinic acetylcholine
receptors at the neuromuscular junction
47. ft'Onset of myasthenia gravis (MG) is slow
and insidious and any skeletal muscle group
may be involved. Onset is most common in
which muscles?
The most common onset of myasthenia gravis is ocular. Ptosis and diplopia
result. If the disease remains localized to the eyes for 2 years, the
likelihood of progression to generalized
48. Identify the anesthetic concerns for the
patient with scoliosis due to muscular dystrophy?
The patient with scoliosis due to neuromuscular disorders, such as muscular
dystrophy, is predisposed to malignant hyperthermia, cardiac dysrhythmias,
and untoward effects of succ inylcholine (hyperkalemia, myoglobinuria,
sustained muscular contraction). [Morgan, et al., Clifl. Anesth..
49 K'What organ produces proopiomelanocortin
(POMC)? What substances
are derived from proopiomelanocortin
(POMC)?
Pro-opiomelanocortin (POMC) is a large preprohormone synthesized
primarily in the anterior pituitary and hypothalamus. Processing of the
preprohormone POMC leads to the formation of a number of smaller,
active peptide hormones, namely adrenocorticotropiC hormone (ACTH),
melanocyte-stimulating hormone (MSH), beta-endorphin, metenkephalin,
and beta-lipotropin. [Guyton & Hall, TMP, Illh ed., 2005,
pp955-957; Nagelhout & Zaglaniczny, NA, 3rd
50. What is the best initial test of thyroid
function in ambulatory individuals?
What is the best initial test of thyroid
function in ambulatory individuals?
51. Calcitonin is released from what organ? Is
calcitonin a weak or a strong regulator of calcium?
Calcitonin is a polypeptide hormone secreted from the parafollicular cells
(C cells) of the thyroid gland. Calcitonin has a quantitatively weak role in
calcium homeostasis in the adult. [Stoelting, PPAP. 4e. 2006 pp808;
52. What is the major physiologic action of
calcitonin?
Calcitonin tends to decrease plasma concentration of calcium ions, due to
a decreased activity of os teoclas ts (bone breakdown) and an increased
activity of osleoblas ts (bone deposition). In general, calcitonin has opposite
effecls 10 those of para~lyroid hormone (PTli). [Stoelting, PPAP. 4e.
2006 pp808; Guyton, TMP. lIe. 2006 pp988-989
53. ....In what vessels would you find the highest
concentration of insulin?
Insulin is produced in the beta cells of the pancreatic islets (of Lan ger~
hans), as you know. Venous blood from the pancreatic islets drains into
the hepatic portal veil!, via the pancreatic vein, and then into the general
circulation. ]Nagelhout & Zaglaniczny
54. @Whichzonaoftheadrenalcortexis the
only one capable of synthesizing aldos terone?
Why is this true?
Aldosterone is synthes ized in the zona glomerulosa alone because this
zona is the only one to contain aldosterone synthase. IBoron, Med Physioi.
2e. 2009 pp1066
55. @)Which two zonae of the adrenal cortex
can synthesize cortisol and corticosterone?
Why?
The zona fasciculata and zona reticularis can synthesize the corticosteroids,
cortisol and corticosterone, because they contain the necessary enzyme,
17-a-hydroxylase for synthesis
56. @)How much daily cortisol is normally
secreted from the adrenal glands? How
much during stress?
The normal adrenal gland can secrete 20 mglday of cortisol and may
secrete up to 200-500 mglday during stress. NB: Both the Barash 2009
Handbook and textbook incorrectly state daily cortisol = 200 mg. [Guyton,
TMP. 11 e. 2006 pp974t; Morgan, et aI., CUn. Anesth
57. @)Perioperativesupplemental steroid coverage
regimens are either low-dose (physiologic)
or high-dose (supraphysiologic). Describe each regimen
Low-dose (physiologic) supplemental steroid coverage: cortisol 25 mg IV
before induction of anesthesia followed by continuous infusion, 100 mg
IV over 24 hr. Supraphysiologic coverage: cortisol 200-300 mg IV in
divided doses on the day of surgery [Barash, Handbook. 6th• 2009 pp790
58. K'What disease is caused by the destruction
of the adrenal gland, resulting in a combined
mineralocorticoid and glucocorticoid deficiency?
Addison's disease (primary adrenal insufficiency) is caused byautoimmune
destruction of the adrenal cortex, causing both glucocorticoid and
mineralocorticoid deficiency. [Morgan, Mikhail, and Murray, Clin. AnesthesioL
59. vDroperidol is to be avoided in the patient
with pheochromocytoma, as you know,
because of the possibility of hypertensive
crisis from catecholamine release. Describe
how droperidol may promote catecholamine
release from the adrenal medulla.
Droperidol (Inapsine) is a potent antidopaminergic (D2 antagonist), with
some histamine and serotonin receptor antagonist activity. The catecholamine
release promoted by droperidol may be due to antagonism of
presynpatic dopaminergic receptors that normally inhibit release of catecholamines
(a normal negative feedback mechanism). [Stoelting & Dierdorf,
Anesthesia and Coexisting
60. Can the liver act as a reservoir for blood?
What controls the rese rvoir functions of the
liver?
Yes, Ihe liver is a majo r reservoir for blood, Sloring up 10 500 mL of blood
at any time. The reservoir function of the liver is dependent upon vascular
tone and vascular pressures. especially on the venous side. Therefore. the
autonomic i'lnervation to the liver will playa crucial role in the reservoir
function of the liver. Intense sympathetic nervous sys tem stimulation
may result in expulsion of up 10 400-500 mL of blood from Ihe liver in a
mallcr of seconds. [Barash, Clillical Alles.. 5e. 2006
61. What percenlage of ca rdiac outpul goes 10
Ihe liver? Whal percenlage of hepalic blood
flow is provided by Ihe porlal vein? By the hepatic artery?
Tolal hepatic blood flow is aboul 25% of ca rdiac OUlpUt. The hepatic
portal vein supplies 70-75% of lola 1 hepalic blood flow; Ihe hepalic artery
provided Ihe remaining 25-30% of lola 1 hepatic blood flolV.
62. ,,",Whal percenlage ofhepalic oxygell mpply
is provided by Ihe portal vein? By Ihe portal
artery?
The hepatic portal vein provides about 50% of total oxygen to the liver
(s ince il is venous blood) and the hepatic artery provides the remaining
50% of lola 1 oxygen 10 Ihe liver. Summary: blood flolV is 75:25 (portal vein
10 hepalic arlery) bUI oxygen supply is 50:50. [Morgan, el ai., Ciill.
63. ,,¥'What two vessels converge to form the
hepatic portal vein?
The hepa tic portal vein is fo rmed by the conHuence of the splenic and
superior mesenteric veins. The portal vein therefore rece ives blood from
Lhe enLi re digestive tract, spleen, pancreas, and gallbladder. [Barash, Clill.
Alles., 5" ed., 2006, p1 073; Stoelting, Hall dbook, 2006, p9840
64. List 4 roles of the liver in protein meta·bolism
The liver has the following 4 roles in protein metabolism: (1) the liver
produces most proteins. wi th the exception of immunoglobins. (2) the
liver synthesizes lipoprotein. (3) the li ver carries out the conversiotl of
amino acids by oxidative deamina tioll into carbohydrates and fatty acids
for the producLion of A TP, and (4) the liver produces urea in order Lo
remove ammonia (from the hepatic deamination process and from bacLe
rial productio n in the gUL). INagelhout & Zaglaniczny, NA, 3rd
65. It'What is the most common major complication of cirrhosis?
Ascites is the most common major complication of cirrhosis
66. It'There are at least three theories describing
the mechanism of ascites formation. All
three theories have a basic event in common;
what is the basic event in the formation of ascites?
67. Consider the patient with cirrhotic liver
disease: would you give the same dose, a
greater dose, or a lesser dose of nondepolarizing
muscle relaxant to this patient?
Cirrhotic liver disease (and renal failure) often results in an increased
volume of distribution and lower plasma concentrations for a given watersoluble drug, such as muscle relaxants. Furthermore, drugs that depend
upon hepatic or renal excretion may have a prolonged clearance.
Thus, depending on the drug of choice, a greater initial loading dose. but
smaller maintenance doses might be required in cirrhotic liver disease.
Vecuronium, pancuronium, and rocuronium blockade are prolonged by
liver disease. [Morgan, Mikhail, and Murray, Clin. Anesthesiol., 4th ed
68. Identify the hallmarks of an acute porphyria attack?
Hallmarks of acute porphyria attacks are abdominal pain, nausea & vomiting,
autonomic disturbances with sweating, tachycardia, sustained
hypertension, and neurological manifestations including seizures and
neuromuscular weakness. Attacks can be life-threatening and neurological
manifestations may be permanent. [
69. Describe renal autoregulation. Which
renal structure appea rs to mediate autoregulation?
Rellal autoregulation is the mechanism by which the kidney maintains
renal blood flow (RBF) and glomerular filtration rate (GFR) thus preserving
solute and water regulation independently of wide fluctuations in
blood pressure. Renal autoregulation typically operates over mean arterial
pressures ranging from 60 mm-Hg to 180 mm-Hg (some texts state 80180 mm-Hg, and others 60- 160 mm-Hg). Renal vascular resistance appears
to be mediated by the va riable resistance of the preglomerular affe- JC
relit arteriole. [Guyton, TMP. lie. 2006 pp323-325; Stoelting, PPAP.
70. State and briefly describe two proposed
mechanism for renal autoregulation?
The most plausible explanations for renal auto regulations are (I) a myogen
ic response in which the arterioles constrict in response to increased
arterial pressure and vice versa. and (2) tubuloglomerular feedback by
way of the juxtaglomerular apparatus. The myogenic response theory
sLates that increased wall tension in the afferent arterioles. due to an
increase in perfusion pressure, causes automatic contrac tion of the
smooth muscle fibers in the vessel wall, thereby increas ing res istance to
flow, and keeping flow constant despite the increase in perfusion pressure.
The tubuloglomerular feedback mechanism proposes that increased
perfusion pressure will increase filtration, increasing the tubular fluid
delivery to the macula densa. which then releases a factor or fac tors that
cause vasoconstriction of the afferent arteriole. [Guyton, TMP. li e. 2006
71.'Identify the 3 major renal processes.
Which of these functions require(s) energy (ATP)?
The three major renal tubular functions are filtration, reabsorption, and
secretion. Of these, reabsorption and secretion are active transport
processes that require energy from ATP hydrolysis. The major energy
source for reabsorption of sodium, the key link to most renal transport
processes, is activity of the Na+ -K+ ATPase (pump). Remember that
"pump" implies an active process, costing A TP-derived energy to move a
substance against its concentration gradient. [Guyton, TMP
72. Which nephron tubular segment is responsible
for approximately two-thirds of all
reabsorption and secretory processes?
Approximately two-thirds of all reabsorption and secretory processes in
renal tubules takes place in proximal tubules
73. What is a countercurrent system? Identify
two countercurrent systems in the human body.
A countercurrent system is an arrangement where inflow runs parallel to,
counter to, and in close proximity to the outflow for some distance. Think
of a U-shaped tube to aid the visualization of this arrangement. In the
human, there are three major countercurrent systems: the loop of Henle
in the nephrons of the kidneys, the vasa recta of the kidneys (capillaries of
the nephrons), and blood flow to the testes through the spermatic arteries and veins
74. ft'Compare and contrast a countercurrent
multiplier system with a countercurrent
exchange system. Which system(s) is used in the kidneys? The testes?
A countercurrent multiplier system, such as the loop of Henle, creates a
gradient along the flow pathway. Specifically, the loop of Henle creates an
increasing osmotic gradient in the interstitium surrounding the loops,
with the maximum osmolality occurring at the tip of the loop of Henle. A
countercurrent exchange system involves a transfer (exchange) of matter
or energy between the inflow and outflow limbs. In the kidney, the vasa
recta exchange solutes and water with the loop of Henle, maintaining the
osmotic gradient in the interstitium. Summary: the kidneys contain both
countercurrent multipliers (loop of Henle) and countercurrent exchangers
(vasa recta). [Ganong, Review of Medical Physiology, 22nd ed., 2005,
75. What is the function of the countercurrent
systems in the kidney?
The countercurrent multipliers (loop of Henle) and exchangers (vasa
recta) allow the kidneys to adjust the osmolality of the urine, that is, to
dilute or concentrate the urine. [Ganong, Review of Medical Physiology
76. What class of drugs causes urinary retention
and thus may interfere with urinary bladder studies?
Opioids cause urinary retention, mediated primarily by mu-1 recepto rs.
Opioids cause a dyssynergia between the bladder detrusor muscle and
urethral sphincter because of failure of sphincter relaxation
77. @)State the specificity and sensitivity of the
fraction excretion of sodium in distinguishing
between peerenal azotemia and acute
tubular necrosis (renal azotemia
The sensitivity and specificity of fractional excretion of sodium of <1 % in
differentiating prerenal azotemia from acute tubular necrosis are 96% and 85%
78. is the most important determinant
of blood viscosity?
The most important determinant of blood viscosity is the hematocrit. A
decrease in hematocrit decreases viscos ity and can improve blood flow.
However. there is a concomitant decrease in oxygen-carrying capacity
with decreased hematocrit and eventually impaired oxygen delivery
79. Fresh frozen plasma (FFP) co ntains all
procoagulant factors except platelets. as you
know. Which factors are most abundant in FFP?
Fac tors V and VIII are most labile and are the most abundant factors in
fresh frozen plasma (FFP).IBarash, Handbook, 5'h ed., 2006, p103: Yao &
Artllsio, Yaa & Artusio's Anesthesiology: Problem-Orieflt ed Pa tient Managelllellt,
5'h ed., 2003, pp381
80. Must fresh frozen plasma (FFP) be ABO
compatible for administration?
Yes, fresh frozen plasma (FFP) must be ABO compatible. I Barash, Handbook
81. Identify 4 general indications to administer
fresh frozen plasma (FFP).
Transfusions offresh frozen plasma (FFP) are indicated for: (I) isolated
coagulation factor deficiencies; (2) reversal of warfarin therapy; (3) correction
of coagulopathies associated with liver disease; and, (4) after
massive transfusions with continued bleeding even after platelet transfusions
82. 'During the preoperative workup, the
patient states they take the herbal supplement
garlic. How long should garlic be
discontinued before elective surgery?
The herbal "Gs" (garlic, ginseng, ginkgo, ginger, guarana, and goldenseal)
should be discontinued 2 weeks before elective surgery in order to restore
no~al anticoagulation status. Note: Miller states discontinue garlic for 7
days prior to elective surgery. [Nagelhout &
83. @>What type of muscle is the pyloric sphinc- The pyloric sphinc ter is a short,
relative poor barrier of smooth muscle
ter? between the stomach and the duodenum. IBoron, Med Physiol. 2e. 2009
pp890
84. lWhat type of muscle is found in the gaostrointestinal tract? Identify the
arrangement of this muscle in the GI tracl
The tunica muscularis of the gastrointestinal tract is comprised of two layers of
smooth muscle: the inner layer is circular, the outer layer is
longitudinal. Specialized circular muscles are called sphincters. [Boron,
Med Pltysiol. 2e. 2009 pp890-891; Guyton, TMP. li e. 2006 pp77l. 7731
85. What is the gastric pH (range) in the fasted patient?
Gast ric pH in the fasted patient ranges from 1.6-2.2. I Kirby. Clill. Alles.
Practice, 2"d ed .• 2002, pl91
86. ®List the electrolyte distu rbances asso cia
ted with anorexia nervosa.
Anorex ia nervosa is characterized by hypokalemia, hyponatremia,
hypochloremia,
and metabolic alkalosis as a res ult of vomiting and laxative
& diuret ic abuse. IHines.
87. Identify the two types of acquired im munity
Acquired immunity is the result of lymphocyte activity and is class ified
into humoral and ce/l-mediated immunities
88. ",What specific lymphocyte class mediates
humoral immunity? Cell -mediated immunityHumoral immunity is mediated by B
lymphocytes whereas T lymphocytes
are responsible for cell -mediated immunity. B lymphocytes get their
name from the origin al discovery of these cells in the bursa of birds. T
lymphocytes are so-named due to their pre-processing and maturation in
the thymus gland. IGuyton. TMP. li e. 2006 pp440-443; Stoelting. PPAP.
89. List two types of mature B lymphocytes
and 4 types of mature T lymphocytes
Differentiated (mature) B lymphocytes may be either memory ceUs or
plasma ce/ls. Mature T lymphocytes are either T-helper (CD4). Tsuppressor
(CD8). T-cytotoxic/killer (CD8). or T-memory cells. [Guyton.
TMP. li e. 2006 pp440-443; Stoelting. PPAP. 4e. 2006 pp856- 8581
90. Which lymphocytes are the so urce of
immunoglobulins (lg)?
Mature B lymphocyte plasma cells are the source of the gamma globulins
known as immunoglobulins. [Guyton. TMP. li e. 2006 pp440- 443; Stoelting.
PPAP. 4e. 2006 pp856-8581
91. Usllhe 5 types of immunoglobulins in
the serum. Approximately what perce ntage
of total serum proteins are immunoglobulins
The 5 classes of immunoglobulins are IgG. IgA. IgM. IgD. and IgE. coll ectively
accounting for approximately 20% of total serum proteins
92. During an aorta-femoral bypass, the
patient becomes hypothermic; what cardiac arrhythmia is likely?
Hypothermia prolongs the refractory period of excitable tissues. In the heart, a
prolonged refractory period leads to sinus bradycardia and conduction defici ts,
which may progress to at rioventricular block and eventually ventricular fibril
lalion.
INagclhout & Zaglaniczny, NA, 3rd cd., 2004, p 11 471
93. Identify 6 physiologic disturbances
caused by hypothermia.
Hypothermia causes the follOwing 6 physiologic disturbances: (1) the
oxyhemoglobin curve is left-shifted-affinity for oxygen is increased and
oxygen will not be as readily released to the tissues; (2) shivering increases
oxygen demand by 400-500%; (3) metabolically-dependent processes,
such as drug biotransformation, are slowed; (4) glomerular filtration rate
decreases; (5) central nervous system depression may be profound; and.
(6) cardiac rate and rhythm disturbances, specifically bradycardia and
premature ventricular contractions occur more frequently. [Nagelhout &
94. What endocrine disorder is associated
with small cell lung carcinoma (SCLC; Oat
cell carcinoma)?
Small cell lung carcinoma (SCLS; Oat cell carcinoma) accou nts for 1525% oflung cancers and is associated with (1) syndrome of inappropriate
ADH seeretioll (SIAOH). (2) ectopic corticotropin secretion. and (3) EatonLambert syndrome. [Stoelting & Oierdorf. Handbook of Anesthesia
95. Describe tl,e pulmonary mec hanics alterations
lhat occur in the patient with endstage scoliosis.
The main alterations in lung mechanics of the patient with end-stage scoliosis are
reduced lung volumes (Ve. TLC. FRC. and RV-aU restrictive process featu res)
and reduced chest wall com·pliance. In the late stages of scoliosis. V/Q mismatching
with hypoxia (due to alveolar hypovell tilation). increased PAP. hypercapnia.
abnormal ventilatory COl response curve. increased work of breathing, and cor
pulmonale occur. c\'entually leading to card iorespiratory failure.INagelhout
96. What is a dose-response curve?
A dose-response curve depicts the relationship between the dose of a drug
administered (x-axis) and the resulting pharmacologic effect (y-axis
97. List four (4) descriptive characteristics of a dose-response curve.
Dose-response curves are characterized by differences in (1) potency, (2)
slope. (3) efficacy. and (4) individual variability. (The graph in Stoelting is
invaluable). IStoelting. PPAP. 4e. 2006 pp 17; Miller
98. Descrihe how potency of a drug is depicted
by the dose-response curve
The potency of a drug is depicted by its location along the dose axis
(usually the x-axis) of the dose-response curve. Increased affinity of a
drug for its receptor shifts the curve to the left, whereas decreased affinity
shifts the curve to the right. Drug potency and receptor affinity are directly
related-a more potent drug has a greater affinity for its receptor.
Mnemonic: Left-shift = Less drug required = More potent. [Sto
99. What does the slope of a dose-response
curve reveal about the drug?
The slope of the dose-response curve indicates the number of receptors
that must be occupied (bound) before a drug effect occurs. A steep doseresponse
curve slope means that a majority of the receptors must be
bound before a relevant effect occurs. Neuromuscular blocking drugs and
inhaled anesthetics dose-resportse cu rves have steep slopes
100. Deftne drug efficacy. Which feature of a
dose -response curve indicates the efficacy of a drug?
Efficacy is a measure of the intrinsic ability of a drug to produce a given
physiologic or clinical effecl. In other words, the maximal effect of a drug
reflects its intrinsic activity, or efficacy. A drug's efficacy is depicted by the
plateau of the dose-response curve. A higher plateau correlates with a greater efficacy
101. Describe how the presence of a competi·
tive antagonist would alter a dose-response
curve of a drug.
The presence of a competitive antagonist (inhibitor) would shift the doesresponse
curve to the right, with no change in the efficacy (plateau) or
slope. The rightward shift is caused by competition for the same number
of receptors. IMiller. Anesthesia. 6e. 2005 pp96; Barash. Clinical Alles ..
102. t"Describe how the presence of a noncompetitive
antagonist would alter the doseresponse
curve of a drug.
The presence of a noncompetitive antagonist (inhibitor) would shift the
curve rightward and downward, with a decrease in the slope of the curve.
The changes occur because a maximal effect cannot be achieved in the
presence of a noncompetitive block. In other words, a noncompetitive
block cannot be reversed by excess agonist. [Miller, Anesthesia. 6e. 2005
pp96; Barash. Clillical Alles .. se. 2006 pp96s0
103. Which volatile agent is completely halogenated
with fluorine?
Desflurane, a methyl ethyl ether, is completely halogenated with fluorin e.
Even though sevoflurane has only fluorine as the halogen substitutions.
sevoflurane is not considered completely halogenated. [Barash, Clin.
104. IIWhich volatile agents most depress the
baroreceptor reflex, and which least depress it?
HaiotJratlc and sevojlurane most depress the baroreceptor reflex (there are
no increases in heart rate despite decreases in blood pressure wi th these
agents). Depression of the baroreceptor response by sevoflurane is comparable
to halothane. In co ntras l, isoJ1urane and des flurane least depress
the baroreceptor reflex (heart rate tends to increase reflex.1y with lhe
decreases in blood pressure produced by these age nts). IStoelting
105. You know that ketamine binds to NMDAtype
glutamate receptors ... which class of
anesthetic drugs also binds to ionotropic
glutamate receptors and then inhibits glutamatergic neurotransmission?
Barbiturates bind to ionotropic glutamate receptors and inhibit neurotransmission
of the excitatory neurotransmitter glutamate. [Miller
106. Rank opioids from most La least lipid soluble.
The order of opioid lipid -solubility ranked from most to least: sufentanil
(1778) >> fentanyl (955) >>> alfen tan il (145) »> meperidine (39) >
remifentanil (17.9) > morphine (1.9). NB: The numbers in parentheses
are the octanol/H20 coefficients, a measure of lipid solubility
107. Which opioid should not be given with a
neuraxialtech nique? Why?
Remifentanil should not be administered inlrathecally or epidurally, as
the safety of the buffering vehicle has not been determined. The buffering
vehicle is glycine. which is an inhibitory neurotransmitter. [Stoelt ing.
108. "What additive is found in etomidate
(Amidate)? What problem may this additive
cause?
Etomidate (Amidate) is provided as an aqueous solution of 0.2% etomidate
and 35% propylene glycol. Propylene glycol may cause pain on injection.
(See MemoryMaster IB3e:Q25 for other drugs formulated with propylene glycol
109. Is there a new formulation of etomidate
that is propylene glycol-free? What is the
new formulation of etomidate?
Etomidate-Lipuro is a new lipid emulsion formulation of etomidate. The
lipid emulsion formulation minimizes pain on injection. [Stoelting,
Handbook,2006,p164}
110. Which intravenous anesthetic agent is
administered as a single isomer?
Etomidate (Amidate) is administered as a single isomer (the D-isomer,
specifically). [Barash, Clin. Anes., 5th ed.,
111. In addition to metabolism in the liver,
propofol undergoes an ex trahepatic foute of
elimination. Identify the ext rahepatic route of elimination of preparo!.
The lungs seem to play an important role in the ext rahepatic metabolism
of propofol. The lungs are responsible for approximately 30% of the uptake
and first-pass elimination after a bolus dose of propofol. Note: for a
drug that is eliminated by hepatic metabolism, if the clea rance rale exceeds
hepatic blood flow, an extrahepatic route of elimination also contri butes
to the drugs clearance. IMiller, Anestiresia
112. Is propofoI a weak acid or a weak base?
Propofol is a weak acid
113. lWhat is the maximal safe dose of cocaine
when applied nasally or topically?
The maximum dose of cocaine is 200 mg for a 70 kg individual, or 3
mglkg (Barash). Stoelting states 150 mg is the single maximum does of
cocaine. NO: be aware of the conflict with Omoigui's Anesthesia Drug
Hatldbook. which states 1.5 mg/kg is the "maximal safe dose of cocain e".
{Barash, Clill. Alles .. 6". 2009 pp1 32B; Stoelt ing, PPAP. 4e. 2006 pp 195;
Omoigui, Omoigui's Anestltesia Drugs. 3e. 1999 pp59J
114. Which local anesthetics are chiral drugs
(possess ing an asymmetric carbon center)?
The pipecoloxylid ide local anesthetics (mepivacaine, bupivacaine. ropivacaine.
levobupivacaine) are chiral drugs because their molecules possess
an asymmetric carbon atom. As such. these drugs may have a left (S) or
right (R) handed configuration. Molecules that are stereospecific superim
posable mirror images of each other and called enQlItiomers. Enantiomers
are optically act ive-they rotate plane polarized light.IStoelti
115. Which two local anes thelics are ad ministered
as racemic mixtures (50:50 mixture of enantiomers)?
Mepivacaille and bllpivacaine are available for clinical use as racemic
mixtu res (50:50 mixture) of the enantiomers. The enantiomers of a chiral
drug may vary in their pharmacokinetics, pharmacodynamics. and toxicity.
Administering a racemic drug mixture is. in reality, the administration of two difTerent drugs
116.ldentify tl,e two local anesthetics that are
pure S ellantiomers. What is the advantage of these local anesthetics?
Ropivacaine and levobupivacaine have been developed as pure S enanHomers
(they are not racemic mixtu res). These S enantiomers produce
less neurotoxicity and cardiotoxicity than racemic mixt ures or the R
enantiomers of local anesthetics. perhaps reflec ting decreased potency at sodium ion channels
117. K'Narne the two active metabolites produced
by lidocaine metabolism
Monoethylglycinexylidide (MEGX) and glycine xylidide (GX) are the
active products ofl idocaine metabolism by liver microsomal P450 sys tem.
118. Is there an active metabolite of succinylcholine?
Yes. Succinylmonocholine is a much weaker metabolite of succinylcholine,
but succinylmonocholine is metabolized much more slowly to succinic
acid and choline. (Revises MemoryMaster IBSa:Q9.) [Miller, Anesthesia
119. All nondepolarizing muscle relaxants are
classified as either benzylisoquinoliniwns or
steroid derivatives. Which nondepolarizing
muscle relaxants are benzylisoquinoliniums
and which are steroid derivatives?
All nondepolarizing muscle relaxants with "curium" in their name are
benzylisoquinoliniums. Thus, mivacurium, atracurium, cisatracuriwn,
doxacuriwn, as well as d-tubocurarine and metocurine are benzylisoquinoliniums.
The nondepolarizing muscle relaxants with "curonium" in
their name are all steroid derivatives. Vecuronium, rocuronium, pancuronium,
and pipecuroniwn are steroid derivatives
120. vWhich two nondepolarizing neuromuscular
relaxants have active metabolites? Compare
the activity of the metabolites to the parent compound.
Vecuronium and pancuronium have active metabolites. specifically the 3hydroxy (3-0H) metabolites (3-desacetylvecuronium and 3desacetylpancuronium). The 3-desacetlyvecuronium metabolite is about
50-70% as potent as vecuronium. whereas 3-desacetylpancuronium has
about 50% potency of pancuronium at the neuromuscular junction. [Barash.
Clill. Alles .. 5,h ed .. 2006. p436; Miller. Anesthesia. 6" ed .• 2005.
121. Carbamazepine (Tegretol) is an antiseizure
medication that works by stabilizing
sodium channels in the inactive conformation
(closed and inactive = no action potentials).
What effects may carbamazepine have
on nondepolarizing muscle relaxants
Nondepolarizing muscle relaxants may have a shorter duration than
expected in the patient receiving chronic carbamazepine therapy. Specifically,
vecuronium clearance is increased 2-fold in the patient receiving
chronic carbamazepine therapy. Anticipate increased dosing and shorter
duration for nondepolarizing muscle relaxants. [Miller, Anesthesia, 6th
ed., 2005, p517; Waugaman, Principles and Pra
122. ,Postoperative muscle pain due to skeletal
muscle fasciculations is a common problem
after succinylcholine administration. How
may you minimize the postoperative skeletal
muscle pain following succinylcholine administration?
In order to minimize fasciculations associated with succinylcholine and
subsequent postoperative skeletal muscle pain, a defasciculating dose
(10% to 15% of intubating dose) of nondepolarizing muscle blocker may
be administered 5 minutes prior to the succinylcholine administration.
Tubocurarine and rocuronium appear to be particularly effective at minimizing
SUCcinylcholine-induced fasciculations, but tubocurarine is no
longer available for use in the U.S. Therefore, rocuronium 0.03-0.04
mglkg (10% ED95) administered 5 minutes prior to succinylcholine administration
is particularly effective at preventing fasciculations. Atracurium
0.02 mglkg is also effective for this application. NB: "Self-taming,"
the administration of a small dose (10 mg) of succinylcholine 1 minute
before intubation does not appear to be effective in preventing fasciculations
123. What is the appropriate premedication
dose of atropine for the adult with severe bradycardia?
As a premedication, atropine is administered intravenously or intramuscularly
in a range of 0.01-0.02 mg/kg up to the usual adult dose of 0.4-0.6
mglkg. Larger intravenous doses up to 2 mg may be required to completely
block the cardiac vagal nerves in treating severe bradycardia Omoigui
states: "0.5-1.0 mg IV/IM/SC, repeat every 3 to 5 minutes as indicated."
[Morgan, Mikhail, and Murray, Clin. Anesthesiol., 4th ed., 2006, p239
124. Identify the incidence of heterozygous
atypical plasma cholinesterase (EuEa) in the
general population. Identify the incidence of
homozygous atypical plasma cholinesterase
(EaEa) in the general population
The incidence of heterozygous atypical plasma cholinesterase (EuEa) in
the general population is about 1 :25, or 4%. The incidence of homozygous
atypical plasma cholinesterase (EaEa) in the general population is about
1:2800, or 0.04%. Two comments: (1) the incidence varies by text reference496 and 0.04% represent reasonable averages; (2) review of table
20-9, page 324 in Barash Handbook is highly recommended
125. l'Which of the 4 common anticholinesterase
agents is not a quaternary ammonium?
Physostigmine is a tertiary amine. Edrophoniurn, neostigmine, and pyridostigrnine
are all quaternary amines. Remember: physostigmine is not
used to reverse neuromuscular blockade because the dose required to
achieve this effect is excessive. Nonetheless. physostigmine is an anticholinesterase
126. 'Rank order the anticholinesterase and
anticholinergic agents based on onset (in
minutes), from fastest to slowest
The order of onset (in minutes) for anticholinergic and anticholinesterase
agents, from fastest to slowest is: atropine (1-2 min), glycopyrrolate (2
min), edrophonium (5-10 min), neostigmine (5-15), and pyridostigmine
(10-20).
127. Rank order anticholinesterase and anticholinergic
agents based on duration (in
minutes), from shortest to longest.
The order of duration (in minutes) for anticholinergic and anticholinesterase
agents. from shortest to longest, is: edrophonium (30-60 min) <
neostigmine (45-90 min) < atropine (60-120 min) = pyridostigmine (60120) < glycopyrrolate (120-240
128. Give 6 contraindications/cautions to
esmolol administration.
Esmolol is contraindicated-or should be used with caution (textbook
variations)-in the follOwing 6 patients: (1) with sinus bradycardia; (2)
with AV heart blocks, especially greater than first degree; (3) with chronic
obstructive pulmonary disease; (4) hypotensive; (5) with cardiogenic
shock; and, (6) with cardiac failure. [Morgan, et al., Clin. Anesth .. 4e. 2006
129. The alpha-2 adrenergic receptor agonist.
c1onidine, acts where centrally to produce
what therapeutic effect?
Stimulation of alpha-2A reccptors of inhibitory neurons in the vasomotor
center of the medulla in the brain stem inhibits sympathetic nervous
system outflow. This action dec reases blood pressu re.
130. Alpha-2 adrenergic receptor agonists
antagonize the sympathetic nervous sys tem
pe ripherally. How?
Alpha-2 receptors are found peripherally in the surface membrane of the
norepinephrine-containing presynap tic nerve terminals of sympathetic
postganglionic neurons. Stimulation of t~ese receptors decreases the
release of norepinephrinc from the presynaptic nerve terminal. This
decreased release of norepinephrine contributes modestly Lo the clonidineinduced decrease in blood pressu re.
131. Sodium nitroprusside contains 5 cyanide
ions (CN-) and may cause cyanide toxicity,
as you know. What three reactions may
cyanide ions (CN-) undergo?
Cyanide ions (CN-) may react in three ways: (1) binding to methemoglobin
to form cyanomethemoglobin, (2) reaction with thiosulfate in the
liver to produce thiocyanide, catalyzed by rhodanese, and (3) binding to
tissue cytochrome oxidase, which interferes with normal oxygen utilization
by the tissues. [Morgan, Mikhail, and Murray
132. How do cyanide ions interfere with oxygen
utilization at tissue cytochrome oxidase?
Binding of cyanide ions to tissue cytochrome oxidase uncouples oxidative
phosphorylation, preventing the formation of ATP
133. List the four hallmark signs and symptoms
of cyanide toxicity
Acute cyanide toxicity is characterized by (1) metabolic acidosis (base
deficit), (2) cardiac arrhythmias, (3) increased venous oxygen content due
to inhibition of cytochrome oxidase and consequent inability of cells to
utilize oxygen, and (4) tachyphylaxis.
134. The patient administered sodium nitroprusside
continuously (by drip) presents
with the following arterial blood gases
(ABGs): pH = 7.21, P.C02 = 32 mm Hg, P.02
= 104 mm Hg, base excess = -10 mEqIL.
What is your next action? Explain the arterial blood gases.
Turn off the nitroprusside drip. These ABGs suggest cyanide toxicity. The
base excess of -10 mEq/L (base deficit of 10 mEq/L) demonstrates that
the acidosis is metabolic. The low PaC02 of32 mm Hg demonstrates
partial respiratory compensation of the metabolic acidosis
135. What is your concern with giving phenytoin
(Dilantin) to the hyperglycemic patient?
Phenytoin (Dilantin) partially inhibits (blunts) insulin release and may
lead to increased blood glucose levels in patients who are hyperglycemic
136. Describe the metabolism and elimination
of adenosine (Adenocard).
Adenosine is rapidly eliminated by enzymatic clearance (less than one
minute). Specifically, adenosine is deaminated in the plasma forming
inosine, or is taken up in erythrocytes (RBCs) and vascular endothelial
cells where it is metabolized to inosine (by deamination) or adenosine
monophosphate (by phosphorylation).
137. D escribe the mechanism of action of
inamrinone (Inocor) and milrinone
Inamrinone (Inocor) and milrinone (Primacor) are phosphodiesterase
(PDE) inhibitors. specifically, selective POEm inhibitors. POEm is cAMPspecific,
thus inamrinone and milrinone will result in increased cAMP in
cells. As you know, the golden rule of signal transduclion is "secondmessengers
are tissue specific." The two major effects of inamrinone and
milrinone occur in the hea rt and in the vasculature. In the heart. in creased
cAMP produced increased inotropy (cAMP is a chemical; chemicals
alter contractility) whereas in the smooth muscle of the vasculature
in creased cAMP promotes smooth muscle relaxalion, vasodilation and
thus decreased systemiC vascular resistance (SVR). Both inamrinone and
milrinone may be called "inodilators" and are not dependent upon adrenergic
receptors ror th eir actions. [Stoelting, PPAP, 4'h ed., 2006, pp236
138. What potential side effect occurs with
inamrinone, but not with milrinone
Inamrinone (Inoco r) can produce thrombocytopenia with long-term
therapy. Milrinone (Primacor) does not produce any apparent effec ts on
plate1ets.[Nagelhout & Zaglaniczn
139. During, what time frame should warfarin be discontinued prior to surgery?
Warfarin should be discontinued 3-5 days prior to surgery
140. In preparation for surgery, when should
the last dose of low molecular weight heparin (LMWH) be given?
The last does oflow-molecular-weight heparin (LMWH) should be given
12 hours before the procedure. [Stoelting & Miller, Basics, Slh ed., 2007,
p343]
141. After the surgical procedure, when should
heparin be restarted?
Heparin should be res tarted 12 hours after the surgical procedure, even in
high-risk patients, because the risk for severe hemorrhage is substantial
142. Following a dose oflow-molecular-weight
heparin, when can a neuraxial intervention be performed?
Neuraxial interventions should be delayed 10-12 hours after a dose of
low-molecular-weight heparin. [Stoelting
143. Iff a neuraxial catheter is in place and a
dose of heparin is given, how long should
you wait before removing the catheter? How
long should you wait before administering the next dose of heparin?
Ncuraxial catheter removal is acceptable 2 to 4 hours after heparin dosing
AND with normal PTf' or ACT. Wait 1 hour after catheter removal to
administer a repeat dose of heparin. [Stoelting
144. Jf a neuraxial catheter is in place and a
dose of low-molecular-weight heparin
(LMWH) is given, how long should you wait
before removing the catheter? How long
should you wait before administering the next dose of LMWH?
Neuraxial catheter removal is acceptable 10 to 12 hours after the last dose
oflow-molecular-weight heparin. Wait 2 hours after catheter removal to
administer the next dose ofLMWH
145. @List eight (8) deleterious effects of methylene
blue administration.
Methylene blue may cause (I) destruction of RBCs with prolonged use,
(2) hypertension, (3) urinary bladder irritation, (4) nausea, and (5) diaphoresis.
Methylene blue (6) may inhibit nitrate-induced coronary artery
relaxation, (7) interferes with pulse oximetry for 1-2 minutes, and (8) can
cause hemolysis in patients with glucose-6-phosphate dehydrogenase
deficiency. [Dunn, et aI., Mass. Gell .. 7e. 2007 pp740
146. List one advantage and one disadvantage
that antacids have over H2-receptor antagonists
for premedication of patients with a potential full stomach
Antacids have an immediate effect, compared to the delayed onset of
effects of Hrreceptor antagonists. Unfortunately, antacids increase gastric
volume, unlike H2-receptor antagonists. [Morgan
147. Give two advantages and one disadvantage
that nonparticulate antacids posses,
compared to particulate antacids
Nonparticulate antacids (sodium citrate or sodium bicarbonate) are much
less damaging to lung alveoli if aspirated, compared to particulate antacids.
Nonparticulate antacids also mix with gastric contents better than
particulate antacids. Nonparticulate antacids, however, lose their effectiveness
30-60 minutes after ingestion, so timing of administration is
critical. Nonparticulate antacids should be given immediately prior to induction.
148. What diuretic can cause ototoxicity (deafness),
especially in patient with renal insufficiency
Loop diuretics, especially furosemide, may cause ototoxicity particularly
in patients with renal insufficiency. This transient or permanent side
effect is most likely to occur with prolonged increases in the plasma concentration
of these drugs in the presence of other ototoxic drugs. [Barash,
Clin. Anes .. 61h• 2009 pp1359; Stoelting, PPAP. 4e.
149. Bleomycin is Loxic to what body organ?
Why does bleomycin accumulate in this organ?
Bleomyci n, an antibiotic/chemotherapeutic, is toxic to the pulmonary
sys tem. Bleomycin is concentrated preferentially in the lung because the
enzyme that inactivates bleomycin (hydrolase) is relatively deficienl in
lung tissue. [Barash, Ciin. Alles., 1997, ppI219- 1223; Stoelting, PPAP,
150. ® Describe phospholipase A, (PLA,).
Phospholipase A2 (PLA2) is the rate-limiting enzyme that catalyzes the
libera tion of arachidonic acid from membrane phospholipids. The liberation
of arachido nic acid is the first step in the production of prostaglandins.
leukotrienes. and thromboxanes (and other substances. too}.
151. @)Howdocorticosteroidsalterphospholipase
A2 (PLA2), ultimately leading to reduced inflammation?
Steroids decrease inflammation by inducing the biosynthesis of a
PLA2inhibitor and preventing subsequent prostaglandin generation.
[Cousins, Neural Blockade
152. Statins {atorvastatin (Lipitor), fluvastatin
(Lescol), lovastatin (Mevacor), pravastatin
(Pravachol), and simvastatin (Zocor)} are
some of the most commonly-prescribed
drugs in the general population. How do statins work?
Statins are drugs that act as inhibitors ofHMG-CoA reductase, the ratelimiting
enzyme in cholesterol biosynthesis. HMG-CoA reductase catalyzes
the conversion of the substrate HMG-CoA to mevalonate. The resulting
inhibition of cholesterol synthesis is accompanied by decreases (up to
60%) in LDL ("bad") cholesterol. (HMG-CoA is hydroxymethylglutaryl
coenzyme A). [Stoelting, PPAP. 4e. 2006 pp587
153. What are the two most-feared side effects
of statin administration? What laboratory
tests should be requested for the patient taking statins?
The two most-feared side effects of statin therapy are (1) liver dysfunction
with elevated haptic enzymes, and (2) severe myopathy with the possibility
of rhabdomyolysis, myoglobinuria, and acute renal failure. Liver function
tests should be performed, up through the morning of the surgery
154. Propofol, a weak acid, has a pKa of 11.0. Is
propofol mostly ionized or mostly unionized
at normal physiologic pH 7.4? Will the dominant
form readily cross membranes or or not
Since the normal physiologic pH 7.4 is less than the pKa 11.0 of propofol,
the body environment is an acidic environmentfor the weak acid propofol.
Remember, the pKa of a given substance is "dividing mark" for acidic
and basic environments. The mnemonic is "acids + acids ~ more
unionized", therefore propofol will be mostly nonionized at physiologic
pH 7.4. The unionized form of a substance is lipid-soluble and thus readily crosses the
membrane
155. Where is glycogen stored in the human
body? How long will glycogen stores supply glucose during starvation?
Glycogen is stored in skeletal muscles (400 g) and in the liver (100 g). The
glycogen sto res will supply about 24 hours of glucose during starvation
co nditions (G uyton says 12 hours). After glycogen stores are depleted,
gluconeogenesis in the liver becomes an increaSingly important source of
glucose. IGanong. Review of Medical Physiology. 22" ed .. 2005. p291. 298
156. N'Which cell membrane receptor involved
in carbohydrate metabolism is a receptor
tyrosine kinase? Describe the function of a receptor tyrosine kinase.
The insulin receptor is a receptor tyrosine kinase (RTK), a specific type of
enzyme-linked receptor. Insulin-mediated stimulation of the tyrosine
kinase activity, which is necessary for normal function of insulin receptors,
is impaired in non-insulin-dependent diabetes mellitus (NIDDM).
The insulin receptor is a tetramer of 2 alpha and 2 beta subunits (a2~2);
the cytoplasmic tails of the membrane-spanning beta subunits possess the tyrosine kinase
activity. Insulin binding stimulates autophosphorylation
of the bela subunits (kinases add phosphates to substra tes). which then
promotes phosphorylation of downst ream targets. See Guyton figure 7S-3
for a good visual aid. IGuyton & Hall. TMP. II 'h cd .• 2005. pp962-963;
Ganong. Review of Medical
157. What effect does hypothermia have on gas solubility'?
As a liquid is cooled. more gas dissolves in the liquid; therefore hypothe
rmia will cause an increase in gas solubility. IParb rook, p8 I; Miller,
Anesthesia. 1994. pp1370
158. What is Dalton's law?
Dalton's law of partial pressures states that the total pressure (TP) of a
group of gases is equal to the sum of their individual partial pressures.
Mathematically, Pleta! = PI + Pz + Pl. [
159. @)What is heat of vaporization? What is the
latent heat of vaporization?
The phase change from the liquid state to the gaseous state is called vaporization.
It takes energy for the molecules in a liquid phase to break away
and enter the gaseous phase. A liquid's heat of vaporization is the number
of calories (a measure of energy) necessary to convert 1 mL liquid into a
vapor. The latent heat of vaporization is more precisely defined as the
number of calories required to change 1 g of liquid into vapor without a temperature
change
160. If atmospheric pressure is 710 mmHg,
and the Oz:NzO delivery is 2L:4L (6L total
flow), what partial pressure of Oz and what
partial pressure ofNzO are delivered to the
patient? Whose law permits these calculations ?
One-third (2/6 = 33.3%) of the delivered gas is Oz, and two-thirds (4/6 =
66.7%) is N10. POz = 0.333 x 710 mmHg = 236 mmHg; PN20 = 0.667 x
710 mmHg = 474 mmHg. Dalton's law of partial pressures permits these
calculations to be made. [West, Respiratory PhYSiology, 1990, p164]
161. @What happens to the temperature of a
liquid as vaporization occurs?
Since vaporization requires energy, the temperature of a liquid decreases
as vaporization proceeds. As the liquid temperature falls, a gradient is
established between the liquid and the surrounding environment. Energy
flows from the warmer area (surroundings) to the cooler area (liquid)this
flow of thermal energy is called heat. At some point, an equilibrium is
reached at which the energy lost (heat) to vaporization is matched by the
energy supplied from the surroundings (heat). [Dorsch, UAE.
162. @Describe what may happen to vapor pressure
if a carrier gas flows through the vaporizer container
As a flow of gas (carrier gas) passes through the vaporizer container,
molecules of vapor are carried away. This causes the equilibrium to shift
so that more molecules enter the vapor phase. Unless some means of supplying
heat is available. the liqUid will cool. As the temperature drops, so
does the vapor pressure of the liquid, and the carrier gas will pick up
fewer molecules so that there is a decrease in concentration in the gas flowing out of the
container
163. A full E-cylinder at 800 psi is connected to
a delivery system set to provide 2 L/min.
How long will the E-cylinder supply provide this flow rate?
A full E-cylinder contains 625 liters at 2200 psi. As a first approximation,
there is about 113 the Original volume remaining, since 800 psi is about
113 of 2200 psi. Since the volume-pressure relationship is essentially
linear, there should be about 1/3 the original volume as well, or approximately
208 liters of gas remains in the cylinder. A volume of208 L running
at 2 L/min will provide approximately 104 minutes of gas at this flow
rate. Specifically, there are 225 L of gas in the cylinder at a gauge pressure
of800 psi: . At a flow rate of2 Umin, the cylinder with 225 L of gas will provide flow for
112.5 minutes
164. @ldentify thefour(4)componentsofthe
anes thesia gas machine that are exposed to
high pressures (cylinder pressure).
The four components of the anesthesia gas machine that are exposed to
high-pressure (cylinder pressure) are: ( I) hanger yoke, (2) yoke block
with check valves, (3) cylinder pressure gauge, and (4) cylinder pressure
regulators. INagelhout, NA. 4'h 2009 pp268; Dorsch, UAE. 5e. 2008 pp86
165. @ldentifytheeight(8)componentsofthe
anesthesia gas machine that are exposed to
jtltermediate pressures (pipeline pressure, 50 psi)
The eight components of the anesthesia gas machine that are exposed to
intermediate pressures (pipeline press ure, SO psi) are; (I) pipeline inlets,
(2) check valves, (3) pressure gauges, (4) ve ntilator power inlet, (5) oxygen
pressu re-failure device, (6) flowmeter valve, (7) oxygen second-stage
regul ato r, and (8) flush valve.INagelhout, NA. 4,h 2009 pp268; Dorsch,
166. @ldentifythefour (4) components of the
anesthesia gas machine that are exposed to
low pressures (d istal to flowmeter needle valve)
The four components of the anes thesia gas machine that are exposed to
low pressures are all distal to the flowmeter needle valve. The components
are: (I ) flowmeter tubes, (2) vapo rizers, (3) check valves, and (4) common
gas outlet. INagelhout, NA. 4,h 2009 pp208
167. Why do some modern gas machines have
2 flowmeter tubes whereas other machines have one flowmeter tube?
The flowmeter arrangement on modern gas machines must account for
both low and high flow rates. A machine with 2 flowmeter tubes in seriesone for low flow rates and one for high flow rates-allows a single
flowmeter to indicate both high and low flow rates. A machine with a
single flowmeter tube actually has dual tapers in the tube-one to accurately
reflect low flow rates and the other for high flow rates. (Recall that
the Thorpe tube flowmeter is a tapered tube.) Memory phrase: Single
taper7dual tubes or dual taper7single tube. [Morgan, Mikhail, and
Murray, CUn. Anesthesiol .• 41h ed., 2006. pS8; Dorsch & Dorsch. UAE
168. @)What is the function of an auxiliary flowmeter
on the gas machine? What is the
advantage of an auxiliary nowmeter?
Auxiliary flowmeters are useful for attaching supplemental oxygen delivery
devices, such as a nasal can nula, to the gas machine. The auxiliary
flowmeter is adva ntageous because the breathing circuit and gas delivery
hose remain intact while supplemental oxygen is delivered to a spontaneously
breathing patient. Another advantage is that an oxygen source is
readily available for the Ambu bag if the patient needs to be ventilated
manually for any reason during the case. [Nagelhout. NA. 4,h 2009
169. ®What is the primary disadvantage of an
auxiliary nowmeter?
If pipeline supply has lost pressure or has been contaminated, the auxiliary
flowmeter becomes unavailable. Another disadvantage is that the
fraction of inspired inspiration cannot be varied with the auxiliary flow·meter
170. Calibration of flowmeters is based upon
what physical property of gases: density or viscosity?
Flowmeters are calibrated for specific gases based upon the gas viscosity
('/) at 10 IV flolVs and the gas density (p) at high flolVs. Recall that with low
flow rates, laminar flow is typically favored and the fluid viscos ity is a key
determinan t oflaminar flow. At high flow rates turbulent flow is more
likely and the fluid density effects the flow. [Morgan. et aI .• Clill. Allesth ..
4e. 2006 ppS8; Barash. Clillical Alles .. se. 2006 ppS66-S67)
171. 'What is the transport ("T") dial setting on
a Drager Vapor 20.n gas machine? What is
the equivalent of this on other gas machines?
The Drager Vapor 20.11 gas machine has a transport ("T") dial setting the
helps prevent tippillg·related problems. This [unction is provided by the
vaporizer cassette systems of other modern gas machines
172. 'What sys tem preven ts filling a vaporizer with the incorrect agent?
The keyed filling port sys tem on modern vaporizers prevents filling with
the incor rect agent. [Morgan
173. @)Which vaporizer is a "dual-circuit" gasvapor
blender? To what feature does the
"dual-circuit" apply?
The Tec 6 vaporizer is an electrically heated, thermostatically controlled,
constant-temperature, pressurized, electromechanically coupled dual
circuit, gas-vapor blender. The pressure in the vapor circuit is electronically
regulated to equal the pressure in the fresh gas circuit. At a constant
fresh gas flow rate, the operator regulates vapor flow using a conventional
concentration control dial. When the fresh gas flow rate increases, the
working pressure increases proportionally. For a given concentration
setting even when varying the fresh gas flow rate, the vaporizer output is
constant because the amount of flow through each circuit remains proportional.
174. 'The Tec 6 desflurane vaporizer is a dualgas
blender, as you know. What are the
implications of this type of vaporizer when a change in altitude is encountered?
Because the Tec 6 vaporizer is a dual-gas blender, the Tee 6 will maintain
a constant concentration of vapor output (% v/v), not a constant partial
pressure, regardless of ambient pressure. This means that at high altitudes,
the partial pressure of desflurane (P des) will be decreased in proportion
to the atmospheric pressure. The Tec 6 vaporizer requires manual
adjustment of the concentration control dial at altitudes other than sea
level to maintain a constant Petes. [Barash, Clin. Anes .. (jib. 2009 pp667175. What is ti,e main function of the check
valve(s) in a gas machine?
Check valves, also called unidirectional or one-way valves. prevent retrograde
flow (back flow) during pOSi tive pressure ventilation, therefore
minimizing the effects of downstream intermittent pressure fluctuations
on inhaled anesthetic concentration. [Dorsch, UA£. 5e. 2008 ppllO
176. Describe the purpose of the fail-safe valve
on the anesthes ia machine
The fail -safe valve prevents the delivery of hypoxic gas mixtures from the
machine in the event offailure of the oxygen supply. The fail -safe valve
goes by Illany other names- the oxygen failure safety valve, oxygen failure
safety device, low-pressure guard ian sys tem, oxygen failure protection device. pressure
sensor shutoff system or valve, pressure sensor system,
and nitrous oxide shutoff valve. [Miller &
177. What are your actions when the oxygen
low-pressure alarm sounds?
When the oxygen low-pressure alarm sounds-indicating profound loss
of O2 pipeline pressure-fully open the E cylinder, disconnect the pipeline,
and consider use oflow fresh gas flows. [Nagelhout
178. What is the proportioning system on the anesthesia workstation?
A proportioning system on the anesthesia workstation is a hypoxia prevention
safety device. Manufacturers equip anesthesia workstations with
proportioning systems in an attempt to prevent creation and delivery of a
hypoxic mixture. Nitrous oxide and oxygen are mechanically and/or
pneumatically linked so that the minimum oxygen concentration at the
common gas outlet is between 23 to 25% depending on manufacturer
179. @Howdoes the Link-25 proportioning system work?
The Link-25 system is found on conventional Datex-Ohmeda machines.
The heart of the system is the mechanical integration of the nitrous oxide
and oxygen flow control valves. It allows independent adjustment of either
valve. yet automatically intercedes to maintain a minimum 25% oxygen
concentration with a maximum nitrous oxide-oxygen flow ratio of 3:1.
The Link-25 automatically increases oxygen flow to prevent delivery of a
hypoxic mixture. A 14-tooth sprocket is attached to the nitrous oxide flow
control valve and a 28-tooth sprocket is attached to the oxygen flow control
valve. A chain physically links the sprockets. When the nitrous oxide
flow control valve is turned through two revolutions. or 28 teeth, the
oxygen flow control valve will revolve once because of the 2: 1 gear ratio.
The final 3:1 flow ratio results because the nitrous oxide flow control
valve is supplied by approximately 26 psig, whereas the oxygen flow control
valve is supplied by 14 psig. Thus, the combination of the mechanical
and pneumatic aspects of the system yields the final oxygen concentration.
The Link-25 proportioning system can be thought of as a system that
increases oxygen flow when necessary to prevent delivery of a fresh gas
mixture with oxygen concentration ofless than 25%. [Barash, CUn. Anes ..
180. @List five (5) conditions that can "fool" the proportion -limiting systems
The following five situations can lead to delivery of hypoxic gas mixtures
on workstations equipped with proportioning systems: (I) wrong supply
gas, (2) defective pneumatics or mechanics. (3) leaks downstream, (4)
inert gas administration, and (5) dilution of inspired oxygen concentration
by volatile inhaled anesthetics. [Barash, CUn. Anes .. 6th• 2009 pp659
181. @What type of gas can lead to delivery of a
hypoxic mixture on a workstation equipped
with a proportioning system? What is mandatory
when such a gas is present?
An inert. third gas, such as He. N2 or C02, can cause delivery of a hypoxic mixture
because contemporary proportioning systems link only nitrous oxide and oxygen.
Use of an oxygen analyzer is mandatory (or preferentially a multigas analyzer) if
the operator uses a third gas. [Barash. Clin. Anes .. 6th• 2009 pp659
182. ©What oxygen sources and delivery pressures
are acceptable for transtracheaJ jet
ventilation? What sources and pressures are
lIot adequate [or transtracheal jet ventilation?
There are several options for the oxygen source and delivery pressures
used with transtracheal ventilation. If a high·pressure system is availa·
ble-for example. a metered and adjustable oxygen source with a hand·
controlled valve and a Luer-Iock connector-1S to 30 psi of oxygen (central
hospital supply or regulated cylinder) can be delivered directly
through the catheter. with insumations of 1 to 1.S seconds at a rate of 12
insufflations per minute. If a 16-gauge catheter has been placed, this
system will deliver a tidal volume of 400 to 700 mL. At a delivered pressure
of 50 psi. a 16·guage delivers 500 mL of oxygen per second. III most
instances, 25 psi is a sufficietlt inspiratory pressure (Nagelhout). Low·
pressure systems cannot provide enough flow to expand the chest adequate·
ly for oxygenation and ventilation (e.g., Ambu bag, 6 psi; common gas
otlt/et, 20 psi). {Barash, Clin. Anes .. 6'h 2009 pp788; Nagelhout, NA. 4,
183. ®Consider a ventilator in pressure co ntrol
mode: what parameter fluctuates with each
cycle? What patient parameters determine this flucation?
In pressure control mode, the ventilator is set so that the inspiratory
pressure is greater than the positive end· expiratory pressure. In this
mode, tidal volume fluctuates (varies) with alterations in patient pulmonary
compliance, pulmonary res istance, and with patient-ventilator asynchrony
184. @>Identifyfour(4) reasons why positive
pressure ventilation of 25 cm H20 would not
be sufficient to ventilate an individual.
Positive pressure ventilation at 25 cm H20 would not be enough pressure
to ventilate if: (1) the upper airway is obstructed, (2) the patient has sufficient
muscle tone to prevent chest expansion, (3) the individual has decreased
pulmonary compliance, or (4) the individual has increased pulmonary
resistance. [Hagberg, Benumofs Airway Management. 2e. 2007
185. ,..'What is the suggested protocol to wean a
patient from synchronized intermittent
mandatory ventilation (SIMV)?
To wean a patient from synchronized intermittent mandatory ventilation
(SIMV), progressively decrease the number of breaths (by 1-2
breaths/minute) as long as the arterial CO2 tension and respiratory rate
remain acceptable (generally < 45-50 mm Hg and less than 30 breaths per
minute). {Morgan, Mikhail, and Murray. CUn. Anesthesiol.. 4th ed., 2006
186. What is the most common site for breathing
circuit disconnection?
Although disconnections can occur anywhere in the breathing system, the
most common site is between the breathing system and tracheal tube
connector or heat-moisture exchanger (HME). [Dorsch
187. Rank the relative efficiency of Mapleson
systems with respect to prevention of rebreathing
during spontaneous ventilation
With respect to prevention of rebreathing during spontaneous ventilation,
the relative efficiency of Mapleson systems is A > DPE > CB. [Miller,
Anesthesia. 6e. 2005 pp293; Barash, Clinical Anes .. Se. 2006 pp578-579;
188. Rank the relative efficiency of Mapleson
systems with respect to prevention of rebreathing
during controlled ventilation.
With respect to prevention of rebreathing during controlled ventilation,
the relative efficiency of Mapleson systems is DPE > BC> A. [Miller,
Anesthesia. 6e. 2005 pp293; Barash, Clinical
189. KYou arc scheduled to provide anesthesia
to a patient with a known susceptibility to
malignant hyperlhermia. How wili you
prepare the gas machine in anlicipation of this case?
The concern in this situation is the presence of trace amounts of volatile
agents in Ihe rubber and plastic components of the gas machine and in
the ventilator and CO2 absorber. The following 3 actions should be taken
to prepare the gas machine for the patient with a known susceptibility to
malignant hyperthermia. (1) The gas machine should be thoroughly
flushed with 100% oxygen for at least IO minutes (0 reIllove residual
traces of volalile agents from rubber and plastic components in the ma chine. (2) The
breathing circuits and CO, canister should be replaced. (3)
Vaporizers should be drained, inactivated, or removed
190. ®When is a nasopharyngeal airway preferable
to an oropharyngeal airway?
A nasopharyngeal airway (nasal airway, nasal trumpet) is better tolerated
than an oral airway if the patient has intact airway reflexes. A nasal airway
is preferable if the patient's teeth are loose or in poor condition, if there is
trauma or pathology of the oral cavity and can be used when the mouth cannot be opened.
[
191. @)List four (4) contraindications to using a
nasopharyngeal airway.
Contraindications to a nasopharyngeal airway include (1) anticoagulation,
(2) basilar skull fracture, (3) pathology, sepsis, or deformity of the
nasal cavity or nasopharynx, and (4) a history of nosebleeds requiring
medical treatment. [Dorsch, UAE. Se. 2008 pp4S4]
192. @)Howdoyouestimatethecorrectlength
for a nasopharyngeal airway?
The length of a nasal airway can be estimated as the distance from the
nares to the meatus (opening) o/the ear. The length should ne 2-4 cm
longer than a corresponding oral airway
193. ®What is the purpose of an oral airway?
List five (S) uses for an oral airway.
Any airway creates an artificial, patent passage to the hypopharynx. Oral
airways are used to (1) prevent the patient from biting an oral tracheal
tube, (2) protect the patient from biting the tongue, (3) facilitate oropharyngeal
suctioning, (4) obtain a better mask fit, and (S) provide a pathway
for inserting devices into the esophagus or pharynx
194. @When is an oral airway indicated? Contraindicated?
An oral airway is indicated for an obstructed upper airway in an unconscious
patient and when there is need for a bite block in an unconscious
patient. An oral airway is contraindicated in the awake or lightly anesthetized
patient-the patient may cough or develop laryngospasm during
airway insertion iflaryngeal reflexes are intact.
195. @)What is the purpose of the laryngoscope
flange?
The flange projects off the left side of the laryngoscope and serves to
sweep the tongue out of the way and to guide instrumentations along the
laryngoscope blade. [Dorsch, UAE. Se. 2008 ppS24J
196. @)What is a lighted intubation stylet and
when is it useful?
A lighted intubation stylet (lightwand, [flexible] lighted stylet, Trachlight",
illuminating or lighted intubating or intubation stylet) uses transillumination
of the soft tissues in the anterior neck to guide the tip of the
tracheal tube into the trachea or to determine the position of the tracheal
tube or other airway device. During direct laryngoscopy, the lighted stylet
can be used to improve the view in the hypopharynx. The lighted stylet is
especially useful in situations where a fiberscope is unavailable or endoscopy
is difficult to perform (e.g .• when an airway is obscured by blood or
secretions or when a patient's head cannot be flexed or extended
197. @Into what shape should a lighted intubation
stylet ("lightwand") be molded? What
approximate angle is the bend of this shape?
For oral intubation. a "r or "hockey stick" bend of approximately 75- to 120degrees just proximal to the cuff is recommended. Care should be taken not to
bend the stylet at the point at which the bulb meets the shaft. [Dorsch. UAE. Se.
2008 pp609; Barash. Clin. Anes .. 61h• 2009 pp1187; Miller & Stoelting. Basics
198. List potential uses for an airway exchange catheter.
An airway exchange catheter (guiding catheter, director, stylet catheter.
catheter guide. elastic stylet. tracheal tube replacement obturator, tube
changer or exchanger, ventilation or exchange bougie, jet-style catheter.
jet stylet, intubation catheter. intubating introducer) can be used for a
number of purposes including: tracheal tube or supraglottic device exchange,
replacing and existing tube, changing a tracheal tube from oral to
nasal, intubation. extubation. to provide ventilation during microlaryngeal
surgery. to provide a useful guide to the trachea during flexible endoscopy.
and facilitating passage of a tracheal tube over a fiberscope.
199. @Whatfeaturesareadvantageous for an
airway exchange catheter? What do these
features afford during extubation?
Airway exchange catheters have a central lumen. and rounded. atraumatic
ends. The catheters are graduated from the distal end. The proximal
end is fitted with either a IS-mm or a Luer-Iock Rapi-Fit adapter, which
can be quickly removed and replaced for ETT removal or exchange. With
these adapters an oxygen source can be used to provide insumated or jetventilated
oxygen if the patient fails extubation and/or if reintubation
over the catheter fails. [Barash. Clin. Anes .. 6th• 2009 pp771]
200. What is an Eschmann introducer?
The Eschmann introducer is a 60-cm. stylet-like device that has a S-mm
external diameter and a 3S-degree bend 2.5 cm from the end that is inserted
into the trachea. Its structure is designed to provide a combination
of stiffness and flexibility. It is more commonly known as the gum elastic
bougie. (although it is not gum. elastic. or a bougie. according to Miller!).
It is an extremely useful instrument when laryngoscopic view is poor or
the tube cannot be otherwise guided into the glottis. It is also useful in
limiting the degree of necessary neck movement during intubation with
potential cervical spine injuries and to lesse~ the risk of dental damage.
The introducer can be manipulated under the epiglottiS. its angled segment
directed anteriorly toward the larynx. Once it has entered the larynx
and trachea. a distinctive" clicking" feel is elicited as the tip passes over
the cartilaginous structures. [Miller. Anesthesia. 6e. 2005 pp1632; B
201. @Inspiratory pressure should be limited to
what value when providing positivepressure
ventilation by a manual resuscitator
(bag-valve mask, for example)?
When providing positive-pressure ventilation with a manual resuscitator.
such as a bag-valve mask. it is imperative to limit the pos~tive pressure to
25 cm H20 to avoid inflating the stomach. which increases the risk of
regurgitation. [Hagberg. Benumofs Airway Management. 2e. 2007 pp36S
202. What is the most common complication
to a patient being jet ventilated?
Tracheal mucosal damage and thickened secretions blocking the airways,
which result from inadequate humidification of the delivered gas, remains
a major problem during high frequency jet ventilation
203. @Ust four (4) indications for electroencephalographic
monitoring during anesthesia.
Four ind ications for EEG monitoring during anesthes ia are: (1) ca rotid
endarterectomy (perfusion jeopardized during cross-clamping of the
caro tid artery), (2) cardiopulmonary bypass procedures, (3) cerebrovasclilar
surgery, for example, temporary clipping during aneurysm surgery
or vascular bypass procedures, and (4) when burst suppression is des ir irable
for ce rebral protec tion
204. @)List two (2) ind ications for electroencephalographic
monitoring in the intensive care unit.
In the intensive care unit, EEG monitoring is indicated (I) for barbiturate
coma for patients with traumatic brain injury, and (2) when subclinical
se izu res are suspected. IBarash, Ciill. Alles .. 6'" 2009 pp I 0091
205. ®Electroencephalogram (EEG) waves are
categorized as alpha, beta, delta, and theta,
based upon frequency and amplitude. Give
the frequency range (in Hz) of each of these
EEG waveforms and the brain region{s)
from which each is recorded.
Delta waves are the lowest frequency (0-4 Hz), greatest amplitude waves
in the electroencephalogram (EEG). Theta waves range from 4 to 7 Hz
and exhibit a slightly lower amplitude than delta waves. Alpha waves are
typically recorded over the posterior aspect of the head during awake,
alert, but relaxed activities. Alpha waves have an intermediate amplitudeless than delta and theta, but greater than beta waves-and a frequency
range of8-12 Hz. Finally, beta waves are the highest frequency (>
12 Hz), lowest amplitude waveforms and are recorded predominantly
over the frontal areas of the head, but can be seen from all brain regions
206. ®Briefly describe the typical brain activities
associated with each electroencephalogram
(EEG) waveform. Reminder: the waveforms
are delta, theta, alpha, and beta.
Delta waves (0-4 Hz) are seen in the sleeping adult, but are considered
abnormal in the awake adult. Delta waves are also seen in encephalopathy,
deep coma, and deep anesthesia. Theta waves (4-7 Hz) are seen in
sleep and in deep anesthesia. Prominent alpha wave activity is characteristic
of awake, alert, but relaxed activities. An "eyes closed" resting alpha
pattern is the baseline awake pattern used when anesthetic effects on the
EEG are described. Beta waves (> 12 Hz) are characteristic of aroused,
attentive, active thinking. [Nagelhout, NA. 41h. 2009 pp350; Barash
207. ®What happens to the electroencephalography
(EEG) waveforms as anesthetic depth increases?
Increasing depth of anesthesia from the awake state is characterized by
increased amplitude and synchrony in the EEG waveforms
208. ® As anesthetic depth increases, periods of
electrical silence occupy greater proportions
of the electroencephalogram (EEG). Give a
synonym for "electric silence" in the EEG.
A period of electrical silence in an EEG is called an isoelectric EEG pattern.
208. ®What MAC correlates with an isoelectric EEG pattern?
An isoelectric pattern dominates the EEG in the range of 1.5 to 2.0 MAC
209. ®During certain surgical procedures, maximal
suppression of cerebral metabolic rate
is desirable to protect the brain during an
ischemic insult. Under such circumstances,
the anesthetic agent can be titrated against
the EEG until the desired effect is achieved.
Typically, instead of an isoelectric EEG, the
goal is a state called burst suppression. Characterize
"burst suppression" on the electroencephalogram (EEG)
Electroencephalogram (EEG) burst suppression is characterized by periods
of isoelectric EEG punctuated by "bursts" of EEG activity. The
"burst" is high-frequency activity and the "suppression" is 0.5- to severalsecond
periods ofisoelectric activity
210. @>The electroencephalogram (EEG) is occasionally
used during cerebrovascular surgery
to confirm adequate cerebral oxygenation.
Identify four conditions or agents that can
produce EEG changes mimicking cerebral ischemia
The electroencephalogram (EEG) changes that accompany cerebral
ischemia can be mimicked by (I) hypothermia, (2) electrolyte disturbances,
(3) marked hypocapnia, and (4) anesthetic agents
211. @)Which intravenous anesthetic agents have
minimal effect on evoked potentials and are
thus compatible with effective monitoring of evoked potentials?
Barbiturates. propofol. and fentanyl/or remifentanil have less of an effect
on cortical evoked potentials and are thus compatible with effective monitoring
of somatosensory evoked potentials (SSEP) and brainstem auditory
evoked potentials (BAEP). [Dunn.
212. What agents will not alter bispectral index
(BIS) monitoring?
Since the bispectral index (B1S) is based upon the hypnotic action of
agents. the BIS is flot affected by opioicls or analgesics. Nitrous oxide
alone will have no effect on SIS. Ketaminc has minimal effect on BIS, and
may slightly increase BIS transiently.IDunn, ct al., Clin. Anes. Procedures
of the Massachusetts General Hospital
213 You are considering in sertion of a central
venous line via the left internal jugular vei n;
what are three risks of using the left jugular vein for cent ral line insertion?
Left-sided ca theterization via the left jugular vein increases the risk of (I)
vascular erosion, (2) pleural effusions, and (3) pUlleture of the thoracic
dllct.leading to chylothorax. [Morgan. Mi
214. Think about a central venous pressure
(CVP) waveform: you know what the a, c
and v waves represent. What do the x descent
and y-descent indicate?
On the central venous pressure (CVP) waveform. the x-descent occurs
during ventricular systole and represents atrial relaxation with downward
displacement of the tricuspid valve. The y-descent occurs during diastole
and represent early ventricular filling through the open tricuspid valve.
215. ®Give three (3) contraindications to use of
a pulmonary artery catheter
Relative contraindications to pulmonary artery catheterization are (1)
complete left bundle branch block, (2) Wolff-Parkinson-White syndrome,
and (3) Ebstein's malformation.
216. ®Where could a central venous or pulmonary
artery catheter be inserted in the patient
with superior vena cava syndrome?
The edema due to superior vena cava syndrome often times necess itates
venous access through the lower extremity. A central venous or pulmonary
artery catheter can be inserted through the femoral vein in such
cases. [Hines. Stoeltillg's Co-existillg. 5e. 2008 pp 184}
217. What three (3) valuable ca rdiovascular
parameters are obtained from an arterial
line?
Invasive arterial blood pressure monitoring provides information regarding
(I) left ventricu lar volume. (2) left ventricular function. and (3) systemic
vascular resistan ce. [Nagelhout & Zaglaniczny, NA. 3rd ed., 2004,
p321
218. What condition or situations result in an
abnormal arterial waveform with a false
elevation of systolic pressure?
A decreased arterial compliance or a decreased transducer system frequency
(ringing or overshoot) produce distortion of the arterial waveform.
This particular distortion produces extra waveforms and results in
overestimation of systolic blood pressure
219. What factors may cause damping of the
arterial pressure transducer system? What
effect does system damping have on arterial blood pressure readings?
Damping refers to how quickly a system comes to rest after being set in
motion. The presence of air bubbles in the tubing, thrombus formation in
the catheter, or inadvertent kinking of the catheter may overly damp the
system. Losses of the dicrotic notch and fine details in the waveform
indicate an overly damped system. Overdamping results in an underestimation
of systolic blood pressure and an overestimation of diastolic pressure;
MAP remains fairly accurate. [Nagelhout
220. Your patient requires arterial cannulation:
list 6 arterial cannulation sites, in order of preference.
Multiple arteries can be used for direct measurement of blood pressure;
the top 6 sites for arterial cannulation are: (1) radial artery, (2) ulnar
artery, (3) brachial artery, (4) axillary artery, (5) femoral artery, and (6)
dorsalis pedis artery. (Note: Morgan, et al. place
221. For each of the 6 arteries listed in the
previous question, list a clinical point of
relevance or interest.
(1) Radial artery: the most commonly selected site for arterial cannulation;
non-tapered catheters are preferred for cannulation of the radial
artery. (2) Ulnar artery: more difficult to cannulate owing to its deeper
and more tortuous course; the ulnar artery is the primary arterial supply
of hand blood flow. (3) Brachial artery: large'and easily identifiable in the
antecubital fossa; insertion site is medial to biceps tendon; can accommodate
an IS gauge needle; median nerve damage is possible. (4) Axillary
artery: the insertion site is at the junction of the pectoral and deltoid
muscles-special kits are now available; nerve damage can result from
hematoma or traumatic cannulation. (5) Femoral artery: provides easy
access in low flow state; the femoral artery is prone to pseudoaneurysm
and formation of atheroma, and there is potential for retroperitoneal
hemorrhage. (6) Dorsalis pedis artery: being the farthest distance from
the aorta, arterial waveforms are most distorted, leading to higher systolic
pressure estimates. [Barash, Clin. Anes., 5th ed., 2006, p675t; Morgan,
Mikhail, and Murray, Clin. Anesthesiol., 4th ed., 2006, ppI23-125; Stoelting
& Miller, Basics, 5th ed., 2007, p30St]
222. What two hemoglobin alterations will
yield falsely high pulse oximeter readings?
Carboxyhemoglobin (carbon monoxide poisoning) will cause falsely high
pulse oximeter readings. Carboxyhemoglobin and oxyhemoglobin absorb
light at 660 nm identically, thus the falsely high reading. Methemoglobin
has the same absorption coefficient at both red and infrared wavelengths;
the resulting 1:1 ratio corresponds to a saturation reading of85% -the
pulse oximeter is essentially "locked" at 85% by the presence of methemoglobin.
Thus, ijS.02 is actually less than 85%, the reading will be falsely
high. [Morgan, Mikhail, and Murray
223. What is the best monitor to detect a disconnection?
According to Stoelting and Miller, capnography and spirometry have the
highest value in detecting disconnection. The next best monitors for
detecting disconnection are pulse oximetry and the stethoscope
224. ®Ust seven characteristics of nondepolarizing
neuromuscular blockade
Seven characterist ics of nondepolarizing NM blockade are: (I) Decreased
lwilch heighl, (2) fade during letany, (3) fade during lrain-of-four (Tl:T4
ral io >0.7), (4) posl-lelanic pOlenlialion, (5) absence of fasciculalions, (6)
antago nism of block by acetylcholineste rase inhibitors, and (7) augmentalion
of block by olher non depolarizing agents. IBarash
225. Describe the basic operation of a forced air warmer
A forced-air warmer (such as the Bair Hugger-, Arizant Healthcare) entrains
ambient air through a microbial filter. The air is warmed using an
thermostat-controlled electric heater, and then blown through a hose that
is connected to an inflatable patient cover. Forced-air warmers are also
known as convec tion warming devices and warm air blowers. IDorsch
226. List 2 standard for forced-air warming
devices.
The u.s. standards ror forced -air warming devices (2002) are (I) the
maximum contact surface temperature shall not exceed 48°C, and (2) the
average contact surface temperature shall not exceed 46°C during normal
conditions
227. State advantages afforded by forced-air
Forced-air warming is safe, simple effec tive. and inexpensive. There are a
variety of ava ilable covers, both disposable and reusable, as well as pediatric
styles. Forced·air warm ing provides more calories-to-cost than other
warming modalities. Fibcropt ic laryngoscopes can be warmed before use
wi th a forced-air device. The forced-a ir warmer can be used to warm the
operating table before the patient is transferred to the table. It can also be
used for cooling. Finally, fo rced-air wa rmers have been used to relieve
claustrophia
228. List some disadvantages of forced-air warmers.
Electric power requirements of forced-air warmers make them unsuitable for field
use. They arc cumbersome 10 transfer or set up in a CT scanner. The forced-air
warmer must occaSionally be removed from the pat ient to expose covered areas.
Finally. many systems do not permit the concurrent use of multiple blankets (Le.,
upper and lower body) without using two separate fo rced-air units_ [Dorsch, UAE
229. Define perioperative blood salvage.
Perioperative blood salvage refers to the recovery of shed blood from the
surgical field or wound drains and readministration to the patient. In
most instances, the process involves "washing" of the salvaged material
with return of only the RBC component of blood. [Barash
230. List seven situations in which intraoperative
blood salvage (IBS) may be employed.
Seven situations in which intraoperative blood salvage (IBS) is commonly
employed are: (l) cardiovascular surgical procedures, (2) aortic reconstruction,
(3) spinal instrumentation, (4) joint arthroplasty, (S) liver
transplantation, (6) resection of arteriovenous malformations, and (7)
occasionally in the management of trauma patient
231. Briefly describe the operation of contemporary
"cell saver" (blood salvage) devices.
What is the hematocrit range of the salvaged
blood aliquots returned to the patient? How
efficient is the modern cell saver?
Contemporary "cell saver" devices anticoagulate the salvaged blood as it
leaves the surgical field, separate the RBCs from other liquid and cellular
elements by centrifugation, and then wash the salvaged RBCs extensively
with saline. The RBCs are typically returned to the patient suspended in
saline in aliquots of 12S or 22S mL with a hematocrit of 4S to 6S%. Approximately
SO% of RBCs are salvaged, therefore anticipate administration of allogenic blood
232. What are the contraindications to intraoperative
blood salvage?
Contraindications to intraoperative blood salvage are the presence of
infection, malignant cells, urine, bowel contents, or amniotic fluid in the
operative field. [Barash, Clinical Anes .. Se. 2006 pp21S
233. ~[dentify expected complications of intraoperative
blood salvage.
The potential complications of intraoperative blood salvage (IBS) are a
function of the reinfusion of materials that might remain after the washing
process. Such materials that escape from the washing process include
fat, microaggregates such as platelets and leukocytes, air, red cell stroma,
free hemoglobin, heparin, bacteria, and debris from the surgical field.
Most of these are in fact removed quite efficiently by contemporary cell
salvage equipment. Bacteria are the exception and contamination of cell
saver return with skin organisms is relatively common
234. What coagulopathy is expected after
intraoperative blood salvage? How would
you manage this coagulopathy?
DHutional coagulopatby is to be expected after intraoperative blood
salvage because the washing process removes essentially all clotting factors
and most platelets. Management is the same as for a dilutional coagulopathy
occurring with administration of homologous or preoperative
autologous donation (PAD) blood. [Barash, Clin
235. Briefly describe the basic operation of a
heat and moisture exchanger (HME).
A heat and moisture exchanger (HME) conserves some exhaled water and
heat and returns them to the patient in the inspired gas. Many HMEs also
perform bacterial/viral fIltration to prevent inhalation of small particles.
The HME is also known as a condenser humidifier, Swedish nose (I),
artificial nose, nose humidifier, passive humidifier, regenerative humidifier,
moisture exchanger, and vapor condenser. [
236. What are the indications for heat and
moisture exchanger (HME) use?
An heat and moisture exchanger (HME) can be used to increase inspired
heat and humidity during both shorL- and long-term ventilation. HMEs
are indicated if the patient is hypothermic and for use in the neonatal
circuit. HMEs may be especially useful in transporting the intubated
patients. IDorsch, UAE. 5e. 2008 pp299
237. List two contraindications to heat and
moisture exchanger (HME) usc.
Heat and moisture exchangers are contraindicated in (1) patients with
thick and copious, or bloody secretions, and (2) patients with a leak thal
prevents exhaled gas from pass ing through the HME (e.g., bronchopleural
fistula, or leaking tracheal tube cuff).
238. fList 5 adull patients who are inappropriate
candidates for ambulatory (ou tpatient)
surgery.
The following 5 adult patients are inappropriate candidates for ambulatory
(ou tpa tient) surgery: (I ) patients expected to have major blood loss or
undergoing major surgery; (2) ASA III and IV patie nts who require complex
or ex tended monitoring or pos topera tive treatment; (3) morbidly
obese pa tients with significant respiratory disease. including sleep apnea;
(4) patien ts with a need for complex pain management; and, (5) patients
with significant fever, wheezing, nasal congestion, cough, or other symptoms
of a recent upper resp ira tory inrection. IDunn, et aI., Clin. Atles.
Procedures of the Massachusetts General Hospital, 7" ed., 2007, p5631
239. List 6 other adull patients who are inappropriate
candidates for ambulatory (ou lpa· tient) surgery.
The following 6 addi tional patients are not appropriate candidates for
ambulatory (ou tpatient) surgery: (I) patients susceptible to malignant
hyperthermia; (2) patients with uncontrolled se izure activity; (3) patients
with acute subs tance abuse; (4) patients wi th active in fection; (5) uncooperative
or unreliable patients; and, (6) pat ients who have no responsible
adult at home duri ng convalescence
240. Which two crystalloid solutions contain potass ium (K')?
The two crys talloid solutions that con tain potassium (K') are isotonic
lactated Ringers (LR) and hype rtonic D5LR
241. Banked blood may go through many
changes before it is infused into the patient.
What factors are absent in banked blood?
Blanked blood is devoid of platelets, factors V and VIII, and 2,3-DPG.
[Nagelhout & Zaglaniczny, NA, 3rd ed., 2004
242. @Wh.t blood product "should" be ABO
compatible, but is not strictly mandatory?
Platelets bear both ABO and HLA (human leukocyte antigen) and therefore
ABO compatibility is ideal because incompatibil ity shortens the
li fespan of the plateiet. However, plateiet ABO compatibil ity is not re quired.
243. Describe the current treatment of dilutiona!
coagulopathy.
Dilution.1 coagulopathy usually becomes a problem during massive
transfusions. Both platelets and coagulation factors are markedly decreased
and must be replaced. They should be administered after laborato
ry documentation of tire deficiency. It is no longer accepted practice to
give fresh rrozen plasma (FFP) routinely after 5 units of packed red blood
cell (PRBC), and it is not proper to give platelets after 10 units ofPRBC.
At present, dilutional coagulopathies appear to be rare, even with the
transfusion or one blood volume. [Yao
244. @Ifan acute hemolytic reaction is suspected,
the blood bank should be notified.
Blood and urine samples should be sent to
the laboratory for examination. What two
immediate tests will be performed on the
specimens?
Immediate tests on the posttransfusion specimen will include (1) a visual
check for hemoglobinemia and (2) a direct antiglobulin (Coombs) test.
The direct antiglobulin test examines recipient RBCs for the presence of
surface immunoglobulins and complemenllf positive, an acute hemolytic
reaction may have occurred and additional testing is indicated to ascertain
the cause, including repeat ABO/Rh type, antibody screen, crossmatching,
and other tests as indicated. The blood bank will determine
whether the unit of blood had been correctly released to the patient. [Barash,
Clin. Anes .. 6th• 2009 pp373; Miller, Miller's Anesthesia, 7th•
245. @)Consider the patient in the lateral decubitus
position with no axillary roll and a pulse
oximeter on the dependent hand. What is
the most likely cause for an apparently low S&02 from the pulse oximeter?
The axillary neurovascular bundle is compressed, compromising blood
flow to the extremity. A small support placed just caudad of the downside
axilla can be used to lift the thorax enough to relieve pressure on the
axillary neurovascular bundle and prevent disturbed blood flow to the
arm and hand. This chest support (inappropriately called an axillary roll
by some) should support only the chest wall and it should be periodically
observed to ensure that it does not impinge on the neurovascular structures
of the axilla. [Barash, Clin. Anes .. 6th• 2009 pp802]
246. KWhat nerves may be damaged during face mask ventilation?
The buccal branch of the facial neTve (CN VII) and the supraorbital branch of the
ITigemillalll erve (CN V)
247. In the lateral position, injuries to what
nerves are most likely? Why?
The common peroneal (fibular) nerve is the most commonly injured
nerve of the lower extremity when the patient is in the lateral position.
The injury results from compression of the common peroneal (fibular)
nerve between the OR table and the head of the fibula. To prevent com·
mon peroneal nerve injury in the lateral position, padding extending from
the knee to the heel should be placed along the lateral aspect of the de·
pendent leg. Injury to brachial plexus because of improper padding of the
chest and head is possible. [Nagelhout & Zaglaniczny, NA. 3e. 2005
pp401; Barash, Clinical Anes .. Se. 2006 pp6S4
248. "'-Describe the use and operation of the fracture table
The orthopedic fracture table consists of a body section to support the
head and thorax, a sacral plate for the pelvis with a perineal post, and
adjustable footplates. The most important features of the table are the
ability to maintain traction on a lower extremity and to obtain surgical
and fluoroscopic access. Because the patients requiring this table are often
in pain, anesthesia is usually induced before the patient is moved to the
table. The supine patient who is placed on a fracture table for repair of a
fractured femur usually has the pelvis retained in place by a vertical pole
at the perineum, with the foot of the injured extremity fIXed to a mobile
rest. A worm gear on the rest lengthens the distance between the foot and
the pelvis so that the bone fragments can be distracted and realigned.
[Miller, Anesthesia. 6e. 2005 pp1163; Barash, Clinical Anes .. Se. 2006
249. ,..-The patient is positioned on a fracture
table; what nerve injuries are possible?
Unless the pole is well padded, severe pressure can be exerted on the
pelvis, and damage can occur to the genitalia and the pudendal nerves.
Complete loss of penile sensation has been reported after use of the fracture
table. The correct position for the pole is against the pelvis between
the genitalia and the uninjured limb. Other possible nerve injuries on the
fracture table include brachial plexus damage (due to extended arm or
arm placed directly across the chest) or lower extremity compartment
syndrome. [Barash, Clinical Anes .. Se. 2006 pp6S2, 1119-1120; Miller
250. @)What is compartment syndrome? What
features characterize compartment syndrome?
Compartment syndrome is a potentially life-threatening position-related
complication that causes damage to neural and vascular structures from
swelling of tissues within a muscular compartment, especially those of the
leg. If perfusion to an extremity is inadequate, a compartment syndrome
may develop. Compartment syndrome is characterized by ischemia,
hypoxic edema, elevated tissue pressure within fascial compartments, and
extensive rhabdomyolysis. [Nagelhout, NA. 4th. 2009 pp427
251. @)How can compartment syndrome in the
leg be precipitated?
Compartment syndrome can be precipitated by intraoperative hypotension
in conjunction with leg elevation that causes low-flow states. Pneumatic
compression boots and fluid extravasation into tissues have been
linked to compartment syndromes. Vascular obstruction of major leg
vessels by intrapelvic retractors, by excessive flexion of knees or hips, or
by undue popliteal pressure from a knee crutch may cause compartment
syndrome. External compression of the elevated extremity by straps or leg
wrappings that are too tight, by the inadvertent pressure of the arm of a
surgical assistant, or by the weight of the extremity against a poorly supportive
leg holder may also precipitate compartment syndrome
252. ®What is the definitive treatment for compartment
syndrome? What sequelae will
ensue if compartment syndrome is not treated
The definitive treatment for compartment syndrome is fasciotomy. If
untreated, compartment syndrome will progress to tissue necrosis with
myoglobinuria and acute renal failure (crush syndrome). Amputation and even death may
occur
253. @State five (5) risk factor for difficult mask
ventilation, from greatest risk to leas l.
Five risk factors for difficult mask ventilation, from greatest to least risk
are: (I) presence of a beard. (2) body mass index >26 kg/m'. (3) lack of
teetll (edentulous). (4) age > 55 years. and (5) history of snoring
254. What is the pressure limit for positivepressure
face mask ventilation?
Positive-pressure ventilat ion via a face mask should nomlally be limited
to 20 em !-hO to avoid stomach inflation
255. List the guidelines to be followed in order
to use a laryngeal mask airway (LMA) during
a laparoscopic procedure.
The follOWing guidelines are recommended for use of the laryngeal mask
airway (LMA) during laparoscopy: (1) the clinician should be an experienced
LMA user; (2) careful patient selection is required (e.g., fasted,
not obese); (3) use correct size LMA; (4) tell the surgeon you are using an
LMA; (5) use a total IV anesthetic technique or volatile agent; (6) adhere
to the "IS" rule: <15 degrees tilt, <15 em H20 intra-abdominal pressure, < 15 minutes
duration; (7) avoid inadequate anesthesia during su rgery;
and, (8) avoid disturbing the patien t during emergence.INagelhout &
Zaglaniczny, NA. 3e. 2005
256. @Youdecidealaryngeal mask ai rway
(LMA) is app ropriate for the ainvay management
of the 9-kg patient, but a 1.5 LMA
is not available; will you use a size I or a size 2 LMA
LMA size selection is critical to its successful use, and to the avoidance of
minor as well as more significant complications. The manufacturer recommends
thal the clinician choose the lurgest size that will fit com/ortably
in the oral cavity, and then inflate to the minimum pressure that allows
ventilation to 20 em H20 without an air leak. Accordingly. a size 2
LMA classic is appropriate for the 9-kg patient (Morgan, et al. 6.5-20
kg .. size 2 LMA).IBarash, c/in. Alles .. 6,h 200
257. @What is the Murphy eye on a tracheal
tube? What is the purpose of the Murphy
eye?
A Murphy eye is a hole through tl,e tracheal tube wall opposite to the
bevel. The purpose of the Murphy eye is to provide an alternate pathway
for gas flow if the bevel becomes occluded. IDorsch
258. @What is the name for tracheal tubes that lack a murphy eye?
Tracheal tubes that lack a Murphy eye are called Magill-type tubes. An
advantage of the Magill-type tube is that the cuff can be placed closer to the tip of the tube
259. ®What does the ASTM require of tracheal
tubes?
The ASTM requires that a radio-opaque marker is placed at the patient
end of the tube or along the entire length of the tube to determine the
position of the tube after intubation. [Dorsch, UAE. Se. 2008 ppS64
260. How will the PaC02 change during the
first minute of low-flow apneic ventilation
(apneic insufflation)? During each minute after the first minute?
During low-flow apneic ventilation (apneic insuffiation), the PaC02 rises
approximately 6 mm·Hg during the first minute, and approximately 3-4
mm-Hg each minute thereafter. By extension, during apnea-from any
cause-PaC02 wi ll rise by 6 mm-Hg during the first minute, and 3-4
mOl-rig each minute thereafter.IMiller, Allesthesia. 6e. 2005 pp1901
261. @>What is Klippel-Fell syndrome? What
other problems are associated with KlippelFell syndrome?
Klippel-Feil syndrome is a musculoskeletal disorder characterized by a
short neck owing to a reduced number of cervical vertebrae, or fusion of
several vertebrae. Movement of the neck is severely limited. Spinal stenosis
and kyphoscoliosis are associated with Klippel-Fell and mandibular
malformations andlor micrognathia may be present. Taken together, the
patient with Klippel-Fell presents as a difficult airway. [Hines, Stoeltin
262. vWhat is Ludwig's angina? What are the
signs and symptoms of Ludwig's angina?
Ludwig's angina is an overwhelming generalized septic cellulitis of the
submandibular region. Ludwig's angina generally occurs after dental
extraction; early signs and symptoms include chills, fever, drooling of
saliva, inability to open the mouth, and difficulty in speaking, as well as
edema of the tongue, neck, and submandibular region. The cause is often
hemolytic streptococci, but may be a mixture of aerobic and anaerobic
organisms. [Barash, Clin. Anes., Slh ed., 2006, P 1009; Stoelting & Dierdorf,
Anesthesia and Coexisting Diseases
263. vDescribe airway management for the
patient with Ludwig's angina.
Airway management in the patient with Ludwig's angina may be extremely
difficult. Preliminary tracheostomy using local anesthesia in the awake
patient is the safest course. Other options-depending upon the patient's
condition and ability to cooperate-include an awake fiberoptic intubation
with an armored tube, or an inhalation induction, preserving spontaneous
respiration, followed by intubation with direct laryngoscopy or
fiberoptic assistance. [Barash, Clin. Anes., Slh ed., 2006
264. ®What two amide local anesthetics and one anestheester
local anesthetic are most often used for infiltration anesthesia?
The two amide local anesthetics most often used for infiltration anesthe sia are lidocaine (0.5% to 1.0%)
and bupivacaine (0.125% and 0.25%)., ester is procaine 0.5%-1%
265. ,¥'The mechanism(s) of differential block of
sensory and motor nerve fibers by local
anesthetics is a controversial topic, at best.
State the clinical progression of fiber block
and list 6 mechanisms that contribute to the
differential block produced by local anesthetics
The clinical progression of differential nerve block by local anesthetics,
from first blocked to last blocked, is autonomic fibers, sensory fibers and
motor fibers. At least 6 factors contribute to differential nerve block by
local anesthetics: (I) the anatomic and geometric arrangement of the
individual fibers in a nerve bundle; (2) the size (diameter) of the individual
nerve fibers; (3) the inherent impulse activity (firing rate, frequency) of
the individual nerve fibers; (4) the variability in longitudinal spread of
agent along the nerve fibers; (5) the effects on ion channels other than the
sodium channel, and (6) the choice oflocal anesthetic. Sensory nerve
fibers fire more often than motor fiber and this may explain to a large
extent why sensory fibers are blocked before motor nerve fibers (Nagelhout).
[Stoelting & Miller, Basics, 5th ed., 2007
266. vWhat two nerves are derived from the
posterior cord of the brachial plexus?
The posterior cord of the brachial plexus gives rise La the axillary and
radial nerves. [Cousins & Bridenbaugh
267. vWhat two nerves are derived from the
lateral cord of the brachial plexus?
The lateral cord of the brachial plexus gives rise to the musculocutaneous
and med ian nerves.
267. N'What two nerves are de rived from the
medial cord of the brachial plexus?
The medial cord of the brachial plexus gives rise to the median and ulnar
nerves. [Cousins & Bridenbaugh, Nellral
268. v'Describe the landmarks and relative
needle location in order to perform a median
nerve block at the wrist.
In order to perform a median nerve block at the wrist, a 22-gauge needle
is directed just medial to the ulnar artery pulse, or, if the ulnar pulse is not
palpable, just medial to the flexor carpi radialis. A total volume of 3 to 5
mL of anesthetic is injected to block the median nerve
269. N'Which segment of the brachial plexus is
targeted in the interscalene approach to a
brachial plexus block? (Hint: branches,
roots, cords, trunks, divisions ... )
The interscalene approach to a brachial plexus block targets the trunks of
the brachial plexus. After the roots emerge from cervical and thoracic
vertebrae (C5-TI), the trunks are sandwiched between the anterior and
middle scalene muscles. Two sheathes of fibrous tissue enclose the trunks
between the scalene muscles, forming the space into which local anesthetics
can be injected to produce brachial plexus block. Mnemonic: Robert
Taylor Drinks Cold Beer (Roots, Trunks, Division, Cords, Branches, in
order from vertebral origins to upper extremity terminations). [Ellis &
Feldman, Anatomy for Anaesthetists. 8e. 2004
270. 'Your patient requires hand surgery:
which upper extremity block would not be appropriate?
The interscalene block is suitable for shoulder and arm surgery, but not
for hand surgery. A supraclavicular, infraclavicular, axillary, or Bier block
may be used for hand surgery. [Morgan, Mikhail, and Murray, Clin. Anesthesiol
271. @>What nerve can be blocked in a popliteal fossa block?
The sciatic nerve can be localized in the upper area of the popliteal fossa.
The goal is to block the sciatic nerve can be blocked before it branches
into the tibial and peroneal nerves. [Cousins, Neural
272. @>List the indications for a popliteal fossa
block.
A popliteal fossa block is used for foot and ankle surgery, short saphenous
vein stripping, and in the pediatric population. The popliteal block provides
improved calf tourniquet tolerance and an immobile foot, compared
to an ankle block. [Cousins, Neural Blockade. 4th. 2009 pp361; Barash,
273. Of the 5 sensory nerves to the ankle and
foot, which 3 lie most superficial?
The most superficial sensory nerves that supply sensation to the foot are
the superficial peroneal, saphenous, and sural nerves. Mnemonic: all
superficial sensory nerves to the foot start with "S." [Morgan
274. With one exception, all sensory nerves to
the foot arise from the sciatic system-name
the sensory nerve to the foot that does not
arise from the sciatic nerve.
The saphenous nerve is a terminal branch of the femoral nerve and the
only innervation of the foot not a part of the sciatic system
275. 'List two indications for a facial nerve (CN
VII) block.
Two indications for a facial nerve (CN VII) block are to relieve spastic
contraction of facial muscles, and to treat herpes zoster involvement of
the facial nerve. [Morgan. Mikhail. and Murray. Clin. Anesthesiol., 4th
276. N'What is the occurrence rate of headaches
following unintentional dural puncture with
an IS-gauge epidural needle while attempting
an epidural anesthetic in the pregnant patient?
When a 17- or IS-gauge epidural needle results in unintentional dural
puncture in the obstetric patient, the subsequent incidence of postdural
puncture headache is as great as 70% to SO%. [
277. You perform a successful epidural blood
patch according to standard policy. How
long should the patient rest and in which position before ambulating?
Following a successful epidural blood patch, the patient should rest in the
supine position for 30-60 minutes (up to 2 hours, according to Yao).
[Nagelhout & Zaglaniczny, NA, 3rd ed., 2004, pl000; Yao & Artusio, Yao
& Artusio's Anesthesiology: Problem-Oriented Patient Management, 5th
278. Describe the onset and patient's description
of tourniquet pain. Which nerve fiber(s) mediate(s) tourniquet pain?
Approximately 45 minutes after the pneumatic tourniquet is inflated, the
patient may complain of dull, aching pain or become restless, even though
adequate analgesia exists for the operation itself. Tourniquet pain usually
becomes more intense with time. The current explanation for tourniquet
pain genesis involves pain transmission through both A delta and C fibers,
and its modulation in the dorsal horn synapses. The C fibers recover
faster as the block wanes, therefore the C fibers may be dominate. The
definitive treatment for tourniquet pain is release of the tourniquet. [Barash
279. ®What agent is the most reliable to elicit
deliberate hypotension?
According to Nagelhout, sodium nitroprusside is the most reliable, potent
agent producing rapid onset of hypotension. [
280. List 3 general types of problems that may
delay awakening during post anesthes ia recovery
The most common causes of delayed awakening in postanesthesia recovery
are: (I) prolonged action of anesthetic drugs (most common). (2)
metabolic causes. and (3) neurologic injury (ra re). INagelhout & Zaglaniczny.
NA. 3rd ed .. 2004. p1149; Stoelting & Miller
281.List 3 metabolic disturbances that may
delay awakening during pos tanesthesia
recovery.
Metabolic causes of delayed awakening include hypoglycemia. hyperglycernia,
and electrolyte disturbances. spec ifically disturbances of sodium.
potassium. and calcium. homeos tasis.
282. @l Identifythe two most common causes of
hypoxem ia in the PACU. Which is the most
common cause of hypoxem ia in the PACU?
Hypoxemia in the PACU is usually caused by hypoventilation. increased
right -to-left in trapulmonary shunting, or both. Increased intrapu lmonary
shunting from a decreased functional res idual capaci ty (FRC) relat ive to
closing capacity is the most commOll cause of hypoxemia following general
anesthesia. The loss of lung volume is often attributed to microatelectasis.
A semiupright pos ition helps mainta in FRC
283. @What are the two most common reasons
for delayed discharge from the ambulatory or office-based surgery facility?
Excessive postoperative pain and emetic symptoms are the most common
causes of delayed discharge from ambulatory surgical facilities and can
lead to unexpected hospital admissions
284. @>List eleven complications of mediastinoscopy.
(1) Hemorrhage. (2) pneumothorax, (3) recurrent laryngeal nerve injury.
(4) airway obstruction, (5) compression of the innominate artery. (6)
chylothorax. (7) air embolism. (8) tension pneumomediastinum, (9)
hemithorax. (IO) phrenic nerve injury. and (II) esophageal injury. [Miller.
Miller's Anesthesia. 7th• 2009 pp1855; Barash
285. @>List the three most frequently encountered
complications of mediastinoscopy, on
order of greatest to least incidence
The most common complication of mediastinoscopy is hemorrhage because
of the proximity of the vessels and the vascularity of certain tumors.
The second most common complication of mediastinoscopy is pneumothorax.
usually right-sided. The third most common complication is
recurrent laryngeal nerve injury. and is permanent in up to 50% of cases
286. @)Identifythesignsofsuperiorvenacava syndrome
Superior vena cava syndrome is due to increased venous pressure, leading
to (1) dilation of collateral veins in the thorax and neck, (2) edema and
cyanosis of the face, neck, and upper chest, (3) edema of the conjunctiva,
and (4) evidence ofincreased intracranial pressure including headache
and altered mental status. [Hines, Stoelting's Co-existing. 5e. 2008 pp183
287. Identify the 2 greatest risk factors predictive
of morbidity in the patient undergoing a
carotid endarterectomy.
The two greatest risk factors for morbidity in the patient undergoing
carotid endarterectomy are cigarette smoking and hypertension-both
risk. factors occur at a 62% incidence rate. [Nagelhout & Zaglaniczny. NA
288. In preparation for aortic or carotid crossdamping,
how much heparin should be
given? When should the heparin be given?
A few minutes prior to aortic or carotid cross-clamping. give 5000 U IV of
heparin. [Dunn, et al., Clin.
289. The patient's abdominal aorta has just
been cross-clamped: what cardiovascular
changes may you see above the clamp?
Following abdominal aortic cross-clamp. the following cardiovascular
parameters are increased above the cross-damp: end-diastolic volume.
end-systolic volume. end-systolic wall stress (tension), systemic vascular
resistance (SVR) and mean arterial pressure (MAP). Taken together, these
increases cause an overall reduction in left-ventricular ejection fraction
and cardiac output. [Nagelhout & Zaglaniczny, NA
290. 'The patient's abdominal aorta has just
been cross-clamped: what cardiovascular
and metabolic changes may you see below the clamp?
Following abdominal aortic cross-clamp. the following cardiovascular and metabolic
changes are seen below the cross-clamp: decreased systemic vascular resistance
(SVR) and mean arterial pressure (MAP). decreased tissue perfusion. hypoxia
leading to anaerobic metabolism. and lactate accumulation from the
anaerobic metabolism. [Nagelhout & Zaglaniczny. NA. 3e. 2005 pp488-490;
Miller. Anesthesia. 6e. 2005 pp2073;
291. Describe the cardiovascular effects and
issues upon release of an abdominal aortic cross-clamp
Following unclamping of the abdominal aortic cross-clamp, there is a
"washout" oflocal tissue mediators (e.g., prostaglandins) and metabolic
products (especially lactate), a decrease in systemic vascular resistance
(SVR), and volume shifts leading to a central hypovolemia and ultimately
decreased venous return to the heart. Decreased venous return leads to
decreased cardiac output and potentially significant hypotension. [Nagelhout
& Zaglaniczny, NA. 3e. 2005 pp488-490; Miller, Anesthesia
292. Describe your plan to manage the potentially
significant hypotension following
release of an abdominal aortic cross-clamp.
The avoidance of significant hypotension with unclamping of an abdominal
aortic cross-clamp requires communication with the surgical team,
awareness of the technical aspect of the surgical procedure, and appropriate
administration of fluids and vasoactive agents. It is essential that
preoperative fluid deficits, intraoperative maintenance requirements, and
replacement of blood loss be accomplished before unclamping. Vasodilators,
if used, should be gradually reduced or discontinued before unclamping.
Potent inhalational agents should be decreased. Moderate
intravascular volume loading (approximately 500 mL) during the immediate
prerelease period is indicated for infrarenal unclamping. Volume
loading in an attempt to maintain an elevated central venous or pulmonary
capillary wedge pressure during the cross-clamp period is not indicated
and may result in significant overtransfusion of fluids and blood
products. Gradual release of the aortic clamp and reapplication or digital
compression if significant hypotension results are important measures in
maintaining hemodynamic stability during unclamping. [Miller, Anesthesia
293. A patient is undergoing surgery that
involves clamping of the thoracic aorta.
What is a major complication of clamping the thoracic aorta?
A major complication of clamping the thoracic aorta is spinal cord ischemia
and paraplegia. The incidence of transient postoperative deficits and
postoperative paraplegia are 11% and 6%, respectively. Higher rates are
associated with cross-clamping periods longer than 30 minutes, extensive
surgical dissections, and emergency procedures. The classic deficit is an
anterior spinal artery syndrome with loss of motor function and pinprick
sensation but preservation of proprioception and vibration. [Morgan,
294. What are the anesthetic goals for intracranial
aneurysm surgery?
The anesthetic goals for intracranial aneurysm surgery are to avoid aneurysm
rupture, maintain cerebral perfusion pressure, and to provide a slack brain
295. State 4 steps to take (hint: 3 drugs, 1
action) for anesthetic induction and intubation
for the patient undergoing cerebral
aneurysm repair.
Anesthetic induction for the patient undergoing cerebral aneurysm repair
should be slow and deliberate. (1) Anesthesia may be induced with either
thiopental (3-5 mg/kg), propofol (1.5-2.5 mglkg) or etomidate (0.5-1.0
mglkg). (2) After loss of consciousness and apnea, care must be taken to
maintain a normal PIC02 and to avoid extreme hyperventilation. Vigorous
hyperventilation will lower P IC02 decreasing CBF. This may lower
ICP to such a degree that if mean arterial pressure (MAP) is maintained
or increased, transmural pressure may be increased, leading to rupture of
the aneurysm. (3) Fentanyl (3 to 5 mcglkg), sufentanil (0.5 to 1.0 mcglkg),
or remifentanil (0.25 to 1.0 mcg/kg) can be added 3-5 minutes before
laryngoscopy to blunt the hemodynamiC response. Isoflurane/
desflurane/sevoflurane is added to deepen the anesthetic. (4) Approximately
90 seconds before laryngoscopy, lidocaine (1.5 to 2.0 mg/kg)
or esmolol (0.5 mglkg) can be added to further blunt the hemodynamic
response to intubation. [Yao, Yao 6- Artusio's POPM. 6e. 2008 pp626
296. @>Describe the Whipple procedure for pancreatectomy
indicated by pancreatic carcinoma
A Whipple resection consists of a pancreaticoduodenectomy, followed by
a pancreaticojejunostomy, a hepaticojejunostomy, and a gastrojejunostomy
297. @>Whatelectrolytedisturbancesareexpected
during a Whipple procedure?
Potential electrolyte disorders in the perioperative period of a Whipple
procedure include: hypocalcemia, hypomagnesemia, hypokalemia, and
possible hypochloremic metabolic alkalosis.
298. K'The patient is schedule for a laparoscopic
cholecystectomy. During which phase of the
procedure is the patient at the highest risk for serious complications?
The patient undergoing Iaparoscopic surgery is at highest risk for serious
complications during the initial establishment of pneumoperitoneum.
During this period of "access and insufflation" the likelihood ofe0 2 embolism
and hemorrhage, the 2 most dreaded complications oflaparoscopy,
is highest. [Nagelhout & Zaglaniczny,
299. K'During a laparoscopic procedure the
patient develops a gas embolus. In what
position should the patient be placed?
If a gas embolus develops during a laparoscopic procedure, place the
patient in the left lateral decubitus position. [Nagelhout
300. JV'Explain how a carbon dioxide embolus
during laparoscopic surgery may produce a decreased ETCO2
In the case of a carbon dioxide embolism. cardiac output decreases and the physiologic
dead space increases. Taken together. these changes cause ETC02 to decrease.
Carbon dioxide embolization may cause a biphasic change in ETC02.
Initially. ETC02 may increase from pulmonary excretion of absorbed carbon
dioxide. as expected during a C02 embolus. The initial increase in ETC02 is then
followed by a decrease in ETC02 as described above.
301. A patient is undergoing laparoscopic
surgery and develops a gas embolism. What is your course of action?
The treatment of gas embolism is to discontinue gas insufflation, discontinue
nitrous oxide, administer 100% oxygen, release the pneumoperitoneum,
position the patient in the left lateral decubitus position, and attempt
to aspirate gas via a central venous catheter.
302. IlList 5 pulmonary function changes associated
with a pneumoperitoneum
Insufflation of the peritoneal cavity causes (I) increased peak inspiratory
pressure (PIP), (2) decreased vital capacity (VC), (3) decreased functional
residual capacity (FRC), (4) increased intrapleural pressure (Ppl), and (5)
decreased respiratory system compliance. [Barash, Clin. Anes
303. ldentify 7 cardiopulmonary signs and
symptoms ofTURP syndrome.
Seven cardiopulmonary signs and symptoms ofTURP syndrome are: (1)
respiratory distress (2) cyanosis. (3) hypertension. (4) hypotension. (5)
widened QRS or increased ST segment. (6) dysrhythmias. and (7) bradycardia
304. ldentify 7 hematologic and renal signs
and symptoms o£TURP syndrome
Seven hematologic and renal signs and symptoms or TURP syndrome are:
(I) Itemolysis. (2) acute renal failure. (3) hyponatremia. (4) hypoosmolarity.
(5) hyperglycinemia. (6) hyperammonemia. and (7) coma.
IKirby. Clin. Anes. Practice. 2"'
305. 'Identify 7 central nervous system signs
and symptoms ofTURI' syndrome
Seven CNS signs and symptoms ofTURP syndrome are: (I) nausea &
vomiting. (2) confusion. (3) twitches. (4) visual disturbances (5) seizures.
(6) paralys is. and (7) shock. IKirby
306. Coagu1opathies are a possible complication
during transurethral resection of the
prostate (TURP). What are the causes of
coagulopathies during TURP?
Dilutional thrombocytopenia from the large volume ofirrigating solutions
used during TURP is not uncommon. Primary fibrinolysis due to
plasmin activation or secondary fibrinolysis due to disseminated intravascular
coagulation may be present Disseminated intravascular coagulation
(DIC)-occurring in less than 1% of TURP, especially in patients
with prostate cancer-is caused by release of tissue thromboplastin and
urokinase type plasminogen activator (uPA) from the prostate. [Morgan,
Mikhail, and Murray, Clin. AnesthesioL, 4th ed., 2006,
307. The 65-year-old male patient is undergoing
awake surgical resection of the prostate
gland. The patient suddenly develops
nausea and vomiting and abdominal pain.
What is the likely cause of these signs and syptoms?
Sudden nausea and vomiting and abdominal pain in the awake patient
undergoing surgical resection of the prostate gland is most likely due to
urinary bladder perforation. The incidence of bladder perforation during
prostate surgery is 1%. Signs and symptoms of bladder perforation are
either extra- or intraperitoneal. Extraperitoneal signs and symptoms of
bladder perforation include: periumbilical, inguinal, or suprapubic pain;
lower abdominal distension, and pain in general. Intraperitoneal signs of
bladder perforation are: abdominal rigidity, distension, and pain; referred
shoulder pain; hiccups, shortness of breath; tachycardia; hypotension or
hypertension; diaphoresis; and, vomiting. Most signs are extraperitoneal and the awake patient
complains of nausea, diaphores is. and retropubic
or lower abdominal pain. [Morgan
308. Idenlify th ree situations thai may prec ip itate
central pontine myelinolysis. What do
these situat ions have in common?
Central pontine myelin olys is is potential complication from TURP syndrome.
orthoptic liver transplantation, and head injury. In each of these
situations, hyponatremia may occur and it is the rapid treatment a/hyponatremia
with hypertonic saline that may lead to central pontine myelinolys
is. Correction of'JypotJatremill mllst begradJlal
309. What is central pontine myelinolysis
(CPM)? Whal are the signs and symploms or
ce ntral pontine myelinolysis?
Central pontine myelinolys is (CPM, aka osmotic demyelination syn·
drome) is a neurologic condition characteri zed by symmetric non in·
flammatory demyelinating lesions in the basis pontis (anterior portion of
the pons). Clin ical signs in clude altered level of consciousness progress ing
to inability lo speak or swallow (pseudobulbar palsy) and then the class ic
"locked· in" syndrome with quad riplegia. CPM is a very serious co ndition
that causes permanent structu ral changes in the brain and often is asso·
cialed with dea lh.]Yao. Yao & Artusio 's
310. lWhat is strabismus?
Strab ismus is misal ignment of the visual axes and is the most frequent
ophthalmic condition requiring surgical repair. Esophoric strabismus
occurs when one eye is turned inward (nasall y). Exophoric strabismus
occurs when one eye is turned outward (temporally). Ifboth eyes are
turned nasally (inward), the proper term is esotropic strabismus
311. lldentify 4 anes thet ic concerns for the
patien t undergoing surgical repair of stra·
bismus.
The four main anes thetic concerns for the pat ient undergo ing surgical
repair of strabismus are: (I) ca rdiovascular effects of ocular medications;
(2) the oculoca rdiac renex; (3) malignallt hyperthermia; and (4) postoperative
nausea and vomiting (PONV, occurs in 50-80% of patients pastope·
ra liveiy). Strabismus is thought 10 refl eci an underlying myopathy, thus
malignant hyperthermia may be more li kely to develop. Avoid succinyl·
choline during strabismus repair surgery. A void opiaids during the pro·
ced ure lo dec rease the incidence or PONV
312. 'State the desired effects of a retrobulbar
block?
The desired effects of a retrobulbar block are 3 <CAs": (1) Akinesia of the
eye; (2) Anesthesia of the eye (specifically, the conjunctiva, cornea, and
uvea), and (3) Abolishment of the oculocardiac reflex.
313. What is the first action to take if the
patient with a double-lumen tube for onelung
ventilation starts to desaturate?
, Ifhypoxia occurs during one-lung ventilation, the position of the doublelumen
tube should be rechecked using a fiberoptic bronchoscope. After tube
pOSition is confirmed, CPAPIO should be administered to the nondependent
lung following a tidal volume that expands the lung. According to
Barash: "the Single-most effective means to increase PIOZ during one-lung
ventilation is the application ofCPAP (5-10 em H20) to the nondependent
lung." [Barash, Clin. Anes., 5th ed., 2006, pp825-828, 833-834]
314. What are the monitoring concerns for the
hyperthyroid patient?
In the hyperthyroid patient cardiovascular function and body temperature
must be closely monitored. The goal is early detection of increased
activity of the thyroid gland, suggestive of thyroid storm onset. Consequently,
monitor the ECG for tachycardia and/or dysrhythmias and closely
follow body temperature.
315. List 6 concerns for the patient undergoing
radical neck dissection.
(1) Weight loss, malnutrition, anemia, dehydration and electrolyte imbalance
can be significant. (2) These patients are often heavy users of alcohol
and tobacco and have bronchitis, pulmonary emphysema, and cardiovascular
disease. (3) These patients may present difficult tracheal intubation
and airway management problems. (4) Manipulation of the carotid sinus
may elicit vagal reflex that causes bradycardia, hypotension, or even
cardiac arrest. (5) Trauma to the right stellate ganglion and cervical autonomic
nervous system during right radical neck dissection can (6) Open neck veins create the possibility of
air emboli during head and
neck surgery. [Miller, Anesthesia. 6th ed., 2005, p2539; Nagelhout
316 @During neck dissection, traction or pressure
on the carotid sinus can cause arrhythmias
like bradycardia or asystole, as you
know. What is the definitive treatment for
the arrhythmia? What agents may be given if the arrhythmia persists?
The treatment for arrhythmias due to traction or pressure on the carotid
sinus during neck dissection is immediate cessation of the stimulus. If the
arrhythmia persists, atropine (0.01-0.02 mglkg) or glycopyrrolate (0.01
mglkg) can be given. [Dunn, et al., Mass. Gen
317. A female patient diagnosed with invasive
breast cancer is having a sentinel node biopsy.
What is a sentinel node? Why do you
expect decreased arterial oxygen saturation
readings from the pulse oximeter?
A sentinel node is the first lymphatic node to drain a specified region. A sentinel
node biopsy is often done in the patient with small, invasive breast cancer who
does not have clinically pathologic lymph nodes. The sentinel node is visualized
by injection of either isosulfan blue vital dye (Lymphazurin) or 99m-technitiumlabeled
sulfur colloid (TSC). The surgeon should inform anesthesia when injecting
the isosulfan blue dye because a transient drop in pulse oximeter readings of 25% is seen frequently. (Jaffe & Samuels, Anesthesiologist's
318. @Describethetransverse rectus abdominus
muscle (TRAM) flap procedure for autologous
breast reconstruction
The transverse rectus abdominus muscle (TRAM) procedure replaces the
breast with an ellipse of abdominal skin and subcutaneous tissue based on
the rectus abdominus muscle. The procedure creates a natural appearing
breast from the patient's own tissue. The abdominal donor site is closed as
though the patient had undergone abdominoplasty ("tummy tuck").
319. @What drugs should be avoided in the
transverse rectus abdominus mUscle
(TRAM) breast reconstruction procedure?
In flap reconstructions, the harvested tissue receives its blood supply
through a single artery and vein. Vasopressors are to be avoided. Many
surgeons prefer that N20 be avoided during the abdominal closure. (Jaffe
& Samuels, Surgical Procedures
320. Identify the major postoperative concern
for the patient who just underwent an anterior
cervical discectomy.
Significant postoperative edema of the larynx and upper trachea should be
expected following an anterior cervical discectomy. The combination of
tracheal retraction with the administration of large amounts of fluids may
cause severe edema of the larynx and upper trachea
321. lThe patient with advanced renal carcinoma
is scheduled for a radical nephrectomy.
List 4 anesthetic concerns for this case
Four anesthetic concerns for the patient undergoing a radical nephrectomy
are: (1) acute blood loss, (2) maintain adequate hydration, (3) watch
for signs and symptoms of pneumothorax if the chest is inadvertently
entered, and (4) venous air embolism is possible. Because the kidney lies
in the posterior upper abdomen adjacent to the posterior diaphragmatic
attachment, the possibility of an intraoperative pneumothorax exists. If
there is unexplained hypotension on closure of the abdomen, suspect a
pneumothorax. [Barash, CUn
322. lWhat is the optimal position for the tip of
a single orifice catheter for aspirating entrained
air from the right atrium?
To aspirate entrained air from the right atrium, it is suggested that the
optimal position for the tip of a single orifice catheter is 3.0 cm above the
junction of the superior vena cava and the right atrium
323. lWhat is the optimal position for the tip of
a multi-orifice catheter for aspirating entrained
air from the right atrium?
To aspirate entrained air from the right atrium, the tip of a multi-orifice
catheter should be placed high in the right atrium, at the junction of the
superior vena cava and the right atrium. [Morgan, Mikhail, and Murray,
324. Identify 3 actions for intraoperative rupture
of a cerebral aneurysm.
Intraoperative aneurysmal rupture necessitates (1) maintenance of MAP
between 40 and 50 mmHg or lower to facilitate surgical control of the
neck of the aneurysm or of the parent vessel. Alternatively, (2) one or
both carotid arteries may be compressed for up to 3 minutes to produce a
bloodless field. (3) Blood that is lost should be continuously replaced with
whole blood, blood products, or colloid solution so that intravascular
volume is maintained. [Nagelhout
325. What population of patients has the
highest risk for perioperalive recurrence of venous thrombos is?
The highest risk for perioperative recurrence of venous thrombosis exis ts
for patients who have experienced thromboemboli during the previous
month. Elective surgery in these patients should be deferred until a 3month co urse of warfarin is completed
326. In addition to the superior laryngeal and
recurrent laryngeal nerves, what nerve may
be injured during endotracheal intubation?
In addi tion to the recurrent and superior laryngeal branches of the vagus
nerve (CN X), the hypoglossal nerve (CN XIl) may be injured during
endotracheal intubation. [Nagelhout & Zaglaniczny
327. What neuroendocrine changes may occur during laparoscopy?
During laparoscopy, excessive intraabdominal pressure and hypercarbia
may activate the sympathoadrenal axis, resulting in increased plasma
levels of epinephrine and norepinephrine. Renin, cortisol, aldosterone,
antidiuretic hormone (ADH), and atrial natriuretic peptide levels are also
increased. [Yao, fao 6- Artusio's POPM. 6e. 2008
328. 'What is rhabdomyolysis?
Rhabdomyolysis (literal: "skeletal muscle breakdown") is skeletal muscle
necrosis due to muscle tissue injury
329. 'List 8 common causes of rhabdomyolysis
The most common causes of rhabdomyolysis are (1) major crush injury,
(2) thermal or electrical injury, (3) acute muscle ischemia due to arterial
occlusion, (4) acute muscle injury induced by prolonged immobilization,
and (5) compartment syndromes, such as occur in hemorrhage or when
vascular insufficiency coexists with edema, (6) malignant hyperthermia,
(7) extreme lithotomy position, and (8) hyperlordotic position. [Miller,
Anesthesia. 6e. 2005 pp804-S05; Barash,
330. v'Which oxygen transport protein released
during rhabdomyolysis may precipitate ARF?
Myoglobin, the oxygen-carrying pigment of skeletal muscle, and hemoglobin
are both capable of causing acute renal failure (ARP). Myoglobin
seems to be a more potent nephrotoxin because it is more readily filtered
at the glomerulus and can be reabsorbed by the renal tubules, where it
inhibits nitric oxide (NO) and induces medullary vasoconstriction and
ischemia. [Barash, Clinical Anes .. 5e
331. Your patient is in hypovolemic shock
secondary to trauma. What anesthetic drugs
should be avoided andlor used cautiously?
The following drugs should be avoided in the trauma patient with shock:
histamine-releasing muscle relaxants (atracurium and mivacurium) and
narcot ics (morphine and codeine). Induction agents should be used cautiously
and in small. incremenlal doses
332. IIYour patient has a traumatic head injury:
which anesthetic drugs are contraindicated and why?
Any agent that causes an increase in intracranial pressure (ICP) is contraindicated
in traumatic head injury. Ketamine, succinylcholine, and
N20 cause increases in ICP and are contraindicated. All inhalation agents
tend to increase ICP-this effect may be attenuated by hyperventilation to
PaC02levels of 28-35 mm Hg. [Nagelhout
333. During the initial assessment of a trauma
patient, you suspect a cervical spine injury.
What five criteria increase the risk for potential
instability of the cervical spine?
Five criteria that increase the risk for potential instability of the cervical
spine are: (1) neck pain, (2) severe distracting pain, (3) any neurological
signs or symptoms, (4) intoxication, and (5) loss of consciousness at the
scene. [Morgan, Mikhail, and Murray
334. liThe patient with a cervical spine injury
must be intubated. How is the cervical spine
best stabilized during laryngoscopy and intubation?
Manual immobilization of the head and neck by an assistant (manual inline
stabilization, MILS) should be used to stabilize the cervical spine
during laryngoscopy and intubation. [Morgan
335. A trauma patient has a partially severed
right arm and is at risk for amputation of the
limb. The patient is taken to surgery for
replantation of the limb. What are the specific
anesthetic concerns for limb replantation?
Microvascular surgery is a key component of limb replantation. The 3
anesthetic concerns during replantation and revascularization of a limb
are: (l) maintenance of blood flow (increase perfusion pressure, avoid
hypothermia, vasodilation, antithrombotics and fibrinolytics), (2) positioning,
and (3) replacement of blood and fluid losses. [Barash
336. N'Which anesthetic drugs are contraindicated
in burns, traumatic cord injuries, and crush injuries?
Succinylcholine may produce dangerous rises in serum potassium levels if
administered 24 hours after thermal (bum), spinal cord, or crush injuries.
[Nageihout & Zaglaniczny, NA
337. What inhalational agent causes a variety
of problems in the trauma patient with a
pneumothorax, pneumocephalus, or pneumoperitoneum?
Nitrous oxide (N20) tends to accumulate in closed spaces and thus should
be avoided in the trauma patient with a pneumothorax, pneumocephalus,
or pneumoperitoneum. [Nageihout
338. @lAdministration of fluids during the initial
phase of fluid resuscitation after thermal
injury (burn) should be titrated to goals
specified by Parke, modified Brooke, or
clinical end-points. What noninvasive monitoring
(hint: laboratory value) may guide fluid mgt?
Careful monitoring of the hematocrit may guide fluid management following
thermal injury. An increase in hematocrit during the first day
suggests inadequate fluid resuscitation because hemolysis and sequestration
are actually expected to cause a decrease in this parameter
339. vDescribe the pharmacokinetic and pharmacodynamic
changes seen in the burn patient
In general, two things can change the volume of distribution in the burn
patient: changes in extracellular volume, and changes in protein binding.
Fluid loss to the burn wound and edema can decrease plasma concentration
of many drugs. About 48 hours after the burn injury, plasma albumin
levels decrease and thus the unbound (free) fraction of albumin-bound
drugs (benzodiazepines, phenytoin, salicylic acid) increases; that is, these
drugs have an apparently larger volume of distribution. Because the
pharmacodynamic effect of a drug is often related to the unbound fraction,
alterations in protein binding affect the efficacy and tolerability of
drug treatment in the burn patient. In contrast, alphal-acid glycoprotein
(AAG) levels are increased following burn injury. Drugs that are bound to
AAG (lidocaine, meperidine, and propranolol) exhibit a decreased free
fraction of drug leading to an apparently reduced volume of distribution.
[Nagelhout & Zaglaniczny, NA, 3rd ed., 2004, p804; Duke, Anesthesia
340. ®Administration of fluids during the initial
phase of fluid resuscitation after thermal
injury (burn) should be titrated to goals
specified by Parke, modified Brooke, or
clinical end·points. If a pulmonary artery
catheter is placed, what three parameters
indicate fluid resuscitation is adequate?
If a pulmonary artery catheter is placed in the patient with thermal injury,
adequate fluid resusc itation is consistent with acceptable cardiac output.
filling pressures, and mixed venous oxygen tension (35 to 40 mm-Hg).
IBarash, eli,1. Alles.. 6''- 2009 pp911J
341. ®What are the guidelines for blood replacement
following thermal injury?
Following thermal injury, blood replacement is usually not initiated until
the hematocrit is below IS to 20% in healthy patients requiring limited
operations, approximately 25% in those who are healthy but need extensive
procedures, and 30% or more when there is a history of pre-existing
cardiovascular disease IBarash, e/ill. Alles.. 6''- 2009 pp9 11
342. How do you assess the function of the
permanent intravenous pacemaker leads
once the leads are placed in the patient?
The integrity of placed permanent intravenous pacemaker leads is evaluated
by an external testing device that measures voltage, threshold,
impedance, and the amplitude of sensed potentials. At an initial voltage
output of 5m V and pulse duration of 0.5 ms, the pacing rate is increased
until 100% capture occurs. At this point, the voltage output is slowly
decreased to determine the minimum voltage that results in a 100% capture
rate (this is the voltage threshold check). The ventricular voltage
should be S 0.8 mV and the atrial voltage should be S 1.5 mY. Lead impedance
should be 250-1000 Ohm at a nominal output of 5 V. The amplitude
of the sensed potentials is usually> 6 m V and> 2 m V for ventricular
and atrial electrodes, respectively. [Morgan, Mikhail
343. .#' Evaluation of cardiac pacemaker function
is difficult when the patient's heart rate is
faster than the pacing rate. What maneuver
can the patient do to slow heart rate and
reveal the pacing impulses?
When a patient's heart rate is faster that the pacing rate of the pacemaker.
ask the patient to perform a Val salva maneuver. The Valsalva maneuver
slows the patient's heart rate so that pacing impulses appear on the ECG.
[Nagelhout & Zaglaniczny, NA. 3e. 2005
344.D uring laser surgery. the choice of endotracheal
tube (ETT) can affect the safety of
the technique. Which ETIs are flammable?
What modifica tions to the ETr reduce flammability?
All standard polyv inyl chloride (PVC) endotracheal tubes are nammable,
and can ignite and vaporize when in contact with the laser beam. Once
ignited and penetrated. a PVC tube can sustain a torch like name. Red
rubber endotracheal tubes wrapped with renective metallic tape do not
vaporize. but instead deflect the laser beam. The unwrapped cuff below
the vocal co rds is still vulnerable to laser inju ry. A silicone tube is more
res istan t to penetration by a C02 laser than other tubes. Ifign ited, a sili -cone tube rapidly becomes a
brittle ash that crumbles easily and may be
aspirated, raising the possibility of future problems with silicosis. However,
the acute injuries are less severe than with red rubber and PVC tubes.
Cuffed endotracheal tubes should be inflated with sterile saline to which
methylene blue has been added so a cuff rupture from a misdirected laser
spark is readily detected by the blue dye and extinguished by the saline.
[Barash, Clinical Anes .. Se. 2006 ppl006
345. Describe the various types oflaserresistant
endotracheal tubes.
The Laser-Shield II is made from silicone with an inner aluminum wrap
and an outer Teflon coating. It is designed for use with C02 and potassiumtitanyl-phosphate (KTP) lasers. The cuff is not laser-resistant and
contains methylene-blue crystals. It should be inflated with water or a
saline solution. The Laser-Flex tube is a stainless steel tube with a smooth
plastic surface and a matte finish to reflect a laser beam. It is designed for
use with C02 and KTP lasers. The wall of the tube is thicker than that of
most other tubes. The adult version has two PVC cuffs and a PVC tip with
a Murphy eye. The two cuffs are inflated by using separate inflation tubes
that run along the inside of the tube. The Sheridan laser tube is a red
rubber tube wrapped with copper foil tape. This is overwrapped with
water-absorbent fabric that should be saturated with water prior to use.
The Norton tube is a reusable, flexible, spiral-wound metal tube with a
stainless steel connector and thick walls. The exterior of the tube has a
matte finish to decrease reflection of the laser beam. It has no cuff. A
separate cuff may be attached, or packing around the tube can be used to
achieve a seal. Studies show this tube is acceptable for use with KTP, NdYAG,
and C02 lasers. It is important to remember that laser-resistant does
not mean laser-proof. Laser-resistant tubes can ignite, especially if manufacturer's
warnings, precautions, or directions for use are not followed.
346. An important concern for both the anesthetist
and patient during laser surgery is
eye protect ion. Describe the ocular damage
that may occur by the laser, based upon the laser wavelength
Ultraviolet (UV) lasers (200-3 IS nm wavelength) may cause co rneal
photokeratitis and cataract formation. Near·UV. visible. and nearinfrared
(IR) (400- 1400 nm) lasers-such as Argon, KTP-YAG, Nd:YAG,
and ruby lasers-cause retillal damage. Mid-IR (1400-3000 nm) lasers
may cause cataracts and far-lR lasers (3000- 10000 nm), such as the CQ,
laser, cause corneal bums. INagelhout & Zaglaniczny
347. Can you relyon the color of protective
lenses to indicate their use for specific lasers?
If not, what protective eyewear cri teria
should be adhered to for proper ocular
protection during laser surgery?
No. you should not rely on the color of protec tive lenses to indicate use for
specific lasers. Protect ive lenses must have the appropriate optical dens ity
(aD) and reflective properties based upon the wavelengths of the beams
encountered. For example. protective eyewear for Nd:YAG laser use
should be marked "ODS or greater for 1.064 nm". INagelhout & Zaglaniczny,
NA, 3rd ed., 2004, pp9S4-9SSJ
Left.
348. What factors contribute to the decreased
functional residual capacity (PRC) in the
neonate and infant during general anesthesia?
The chest wall in infants is less rigid (more compliant) because ribs are
cartilaginous and not bony. In addition, the boxlike configuration of an
infant's thorax permits less elastic recoil than the dorsoventrally flattened
thoracic cage of the adult does. Additionally, an infant is more wlnerable
to muscle fatigue, which may further decrease the stability of the chest
wall. As a result of all these factors, an infant's chest wall is extremely
compliant. The net effect of the compliant chest wall and the poorly compliant
lungs is a reduced functional residual capacity (PRe). [Miller,
Anesthesia. 6e. 2005 pp2842; Davis & Motoyama, Smith's Anes
349. 'Is the infant larynx located higher, at the
same, or at a lower level in the neck compared
to the adult larynx? Identify the level
of the infant larynx
The infant larynx is located higher in the neck, at the level of C3-4 than in
the adults, where the larynx is located at the level ofC4-5. Author's comment:
I find these text statements somewhat misleading-as you know,
the cricoid cartilage-certainly part of the larynx-lies at C6, and many
texts (Miller, for example) state that the adult larynx ranges from C3-C6.
Perhaps the more accurate statement is: the thyroid cartilage is located at
C3-4 in infants compared to C4-5 in adults. [Miller & Stoelting. Basics.
5e:2007 pp233; Cote, PAlCo 3e. 2001
350. During the preoperative evaluation of a 6month-old surgical candidate, you note
physiologic anemia. What is a likely cause
for the physiologic anemia?
The infant with physiologic anemia at 6 months of age is most likely a
formerly premature infant (expremie). "Even at several months of age,
expremies remain anemic because of poor nutrition and delayed hematopoiesis
that is induced by earlier transfusions." Reminder: the nadir (low
point) of physiologic anemia typically occurs at 2-3 months for full-term
infants. [Gregory, Ped. Anes., 41h ed., 2002, p373; Cote, PAIC, 3rd ed.,
2001, p20; Yemen, Ped. Anes. Handbook
351. Non-shivering (cellular) thermogenesis is
a crucial heat-generating mechanism in the
neonate and infant, as you know. At approximately
what age does non-shivering thermogenesis
cease to be clinically significant?
Clinically and physiologically significant non-shivering thermogeneSis
persists up to the age of2 years. Non-shivering thermogenesis may continue
into adulthood, but generally is not a relevant and significant source
of heat generation in the adult. [Davis & Motoyama, Smith's Anes. for
Infants and Children. 7e. 2006 pp162
352. What hemodynamic alteration may worsen
(increase flow through) a left-to-right intracardiac shunt?
An increase in systemic vascular resistance (SVR) may increase left-toright
intracardiac shunt flow, such as occurs in atrial septal defect. Avoid
interventions that may increase SVR in the patient with an ASD.
353. A right-to-left intracardiac shunt is
present in the patient with a ventricular
septal defect (VSD). What hemodynamic
alterations may worsen (increase shunt
flow) the right-to-left shunt ofVSD?
An abrupt increase in pulmonary vascular resistance (PVR) or a decrease
in systemic vascular resistance (SVR) is poorly tolerated in the patient with
ventricular septal defect (VSD). Avoid interventions that may increase
PVR or decrease SVR in the patient with a right-to-Ieft intracardiac shunt
354. A right-to-left intracardiac shunt is
present in the patient with a ventricular
septal defect (VSD). What hemodynamic
alterations may worsen (increase shunt
flow) the right-to-left shunt ofVSD?
An abrupt increase in pulmonary vascular resistance (PVR) or a decrease
in systemic vascular resistance (SVR) is poorly tolerated in the patient with
ventricular septal defect (VSD). Avoid interventions that may increase
PVR or decrease SVR in the patient with a right-to-Ieft intracardiac shunt.
355. Will a right -to-left intracardiac shunt
theoretically slow or accelerate inhalation
induction? Is the effect be clinically significant
A right-to-Ieft intracardiac shunt will theoretically slow inhalation induction,
because less anesthetic is absorbed from the lung, and mixing will
further dilute blood passing to the left, decreasing the arterial concentration
of the blood going to the brain, especially the less soluble agents. This
effect is rarely problematic. [Fleisher, Anesthesia
356. WilI a right-to-Ieft intracardiac shunt
theoretically slow or accelerate intravenous induction?
An intravenous induction will be theoretically accelerated with a right-toleft
intracardiac shunt. [Fleisher
357. 'Will a left-to-right intracardiac shunt
theoretically slow or accelerate inhalation
induction? Why is this phenomenon rarely evident clinically?
A left-to-right intracardiac shunt should accelerate the speed of inhalation
induction because the rate of transfer of anesthetic agent from the lungs
to the blood is increased. However, this effect is rarely clinically evident
because decreased delivery of anesthetic to the target tissues negates the
increased uptake of agent with a left-to-right intracardiac shunt. [Fleisher,
Anesthesia and Uncommon Disease, 5th ed., 2006 p91; Barash
358. Will a left-to-right intracardiac shunt
theoretically slow or accelerate intravenous
induction? Why is this phenomenon rarely evident clinically?
Intravenous induction should be slowed by a left-to-right shunt; however,
unless cardiac output is very poor, the effect is clinically irrelevant
[Fleisher, Anesthesia
359. Describe the suggested tracheal intubation
technique for a patient with Treacher Collins syndrome
Treacher-Collins syndrome is the most common of the mandibulofacial
dystoses, a group of syndromes that feature mandibular hypoplasia. In
addition, up to 30% ofTreacher-Collins patients have an associated cleft
palate. An awake tracheal intubation (oral or nasal) with aid of a fiberoptic
laryngoscope after adequate topical anesthesia is recommended. Miller
advocates: (1) topicalization with 1% lidocaine, (2) LMA insertion, followed
by (3) fiberoptic intubation through the LMA. Also consider fiberoptic
tracheal intubation after induction with a volatile agent. [Stoelting
& Dierdorf, Handbook of Anesthesia and Co-Existing
360. ®Treacher-Collins syndrome is associated
with cleft palate, as you know, indicating a
difficult airway. What congenital heart
disease is associated with Treacher-Collins syndrome?
Treacher-Collins syndrome is frequently accompanied by congenital heart
disease, most prominently ventricular septal defect. Concept: ventricular
septal defect is the most commonly occurring congenital heart disease,
therefore VSD is frequently associated with many other congenital anomalies.
[Hines, Stoelting's Co-existing. 5e. 2008 pp613; Yao, Yao 6- Artusio's
361. @)In addition to cleft palate and ventriculo septal
defects. what other conditions are
associated with Treacher-Collins syndrome?
Is a macroglossia (large tongue) associated with Treacher-Collins syndrome?
Treacher-Collins syndrome is associated with cleft palate (30%). venlriculoseptal
defect (VSD), malar hypoplas ia, colobomas (notching of the
lower eyelid s), macrostomia (large mouth), malocclusion, and a small
oral cavity. Treacher-Collins syndrome is not associated with macroglossia
(large tongue) or mental retardation.
362. @) List three (3) treatments for postintubation
laryngeal edema (postintubation “croup”
Treatment of postintubalion laryngeal edema ("croup") is aimed at reducing
airway edema. Mild cases of len improve with cool, humidified mist
and oxygen therapy. ideally administered by a face tenl. More severe cases require hourly administration of
aerosolized racemic epinephrine, 0.05
mLlkg of 2.25% epinephrine in 3.0 mL of saline. Intravenous dexamethasone
(0.25-0.5 mglkg) may prevent the edema, but the effect takes up to
4-6 hours to manifest
363. @Identify ten (10) factors associated with
postintubation laryngeal edema ("croup").
The following ten factors are associated with postintubation laryngeal
edema ("croup"):
(1) age younger than 4 years, (2) tight-fitting endotracheal tube, no audible
leak at 15-25 em H20, (3) traumatic or repeated intubation, (4) prolonged
intubation, (5) high-pressure, low-volume cuff, (5) patient "bucking"
or coughing during intubation, (6) head repositioning while
intubated, (7) history of infectious or postintubation croup, (8)
neck/airway surgery,
(9) upper respiratory infection, and (10) Trisomy 21.
364. @What is the most common cause for liver
transplantation in children?
In children, the most common cause for liver transplantation is cholestatic
liver disease secondary to biliary atresia, particularly in infants (50%).
365. Positive pressure ventilation by bag and
mask has been instituted on the neonate
during resuscitation. When is endotracheal intubation indicated?
During neo natal resuscitation, prompt endotracheal intubation is indicated
if there is no immediate «30 seconds) improvement in the clinical
co ndition of the neonate with positive-pressure ve ntilation with a face
mask. (There are many steps in the algorithm for resuscitat ion of the
newly born in fant at which endotracheal in tubation may be considered:
see Chestnut, page 133 for the complete algorithm.)
366. When should immediate endotracheal
intubation be considered during neonatal recussisation?
Immediate endotracheal intubation of the neonate should be considered
for situations in which bag and mask ve ntilation is likely to be ineffective,
for example. extreme prematurity with low pulmonary compliance secondary
to surfactant deficiency. Other situat ions in which bag and mask
ven tilation may be ineffective are large bilateral pleural effusions and
congenital diaphragmatic hernia
367. What size (French) suction catheter
should be used to clear the endotracheal
tube of the intubated neonate? The intubated
2-year-old? The intubated 6-year-old?
The appropriate size (French) of suction catheter for clearing the endotracheal
tube of the intubated child is: neonate-8 Fr, 6 months to 2 years
old-IO Fr, and 2 to 12 years 01d-14 Fr
368. Surgery in neonates poses a major concerndevelopment of apnea in the postoperative
period. Which neonates are at the
highest risk for postoperative apnea?
Neonates at highest risk for postoperative apnea are those born prematurely,
those who have multiple congenital anomalies, those with a history
of apnea and bradycardia, and those with chronic lung disease
369. Would a formerly premature infant be a
candidate for outpatient surgery? What are
the anesthetic concerns for the formerly premature infant?
No, the formerly premature infant is not an appropriate candidate for
outpatient surgery. Formerly premature infants (less than 46 weeks postconceptual
age), even ifhealthy, have an increased rate of post-anesthetic
apnea and bradycardia. These formerly premature infants should have
cardiorespiratory monitoring for a minimum of24 hours postoperatively
and thus are not good candidates for ambulatory day surgery
370. The infant patient is high-risk for postoperative
apnea what agent may be given
prophylactically to decrease the risk of apnea?
The infant at risk for postoperative apnea may be given caffeine prophylactically
to ensure adequate serum levels exist prior to surgery and during the postoperative
period. Caffeine is a respiratory and CNS stimulant and is generally preferred
to theophylline because caffeine has a wider therapeutiC margin and a decreased
propensity for toxicity. The recommended loading dose is 10 mglkg of caffeine
base, which is often obtained from 20 mg of caffeine citrate. The clinical effects of
caffeine may last several days after a single dose, but do not administer caffeine
and then discharge the patient, assuming that the caffeine will prevent apnea
371. ®What is retinopathy of prematurity?
Retinopathy of prematurity (ROP), formerly known as retrolental fibroplasia,
is a fibrovascular proliferation overlying the retina that leads to
progressive visual loss. ROP occurs almost exclusively in preterm infants.
The risk ofROP is inversely proportional to birth weight, and is associated
with neonatal oxygen exposure, apnea, blood transfusion, sepsis,
and fluctuating levels of carbon dioxide. [Cote, PAlCo 4th. 2009 pp64;
372. @) At what gestational age does the risk of
retinopathy of prematurity become negligible? Why?
The risk of retinopathy of prematurity becomes negligible after 44 weeks
postconception because retinal vasculogenesis is complete between 42-44
weeks postconception.
373. What is the appropriate volume for a
pediatric epidural blood patch?
In the child who is awake, the practitioner should stop the blood infusion
once the child feels discomfort of pressure in the back. In the anesthetized
patient, no more than 0.3 mLlkg of blood should be injected into the
epidural space.
374. ,..-State 3 reasons why the uptake of anesthetic
drugs is typically faster in children than in adults.
Uptake of anesthetic drugs is faster in children than adults for the following
3 reasons. (1) The Childs higher alveolar ventilation per weight accounts
largely for this effect. (2) Increased cardiac output with greater
distribution to the vessel-rich groups combined with lower muscle mass
allows more of the agent to concentrate in vital organs, especially the
brain. (3) Anesthetic agents appear to be less blood soluble in children
than in adults, that is, the agents work faster in children than adults.
375. What is the most commonly used analgesic
for pediatric outpatients?
Acetaminophen is the most commonly used mUd analgesic for pediatric
outpatients. The initial dose is often administered rectally (up to 45
mglkg) prior to awakening from anesthesia. Supplemental doses are then
given orally (10 mglkg every 4 hours or 20 mglkg every 6 hours) to maintain
adequate blood levels and effective analgesia.
376. What is the drug of choice and dosing for
prophylaxis for pediatric endocarditis?
Standard general prophylaxis for pediatric endocarditis is amoxicillin, 50
mglkg orally 1 hour prior to procedure.
377. The pediatric patient is scheduled for a
radiofrequency ablation of an aberrant
conduction pathway (e.g., Wolff-ParkinsonWhite
syndrome). Why is a general anesthetic
typically required for this scenario?
Radiofrequency ablation is a nonsurgical approach designed to eliminate
atrial or ventricular re-entrant tachyarrhythmias. The technique requires
mapping and precision ablation of the aberrant pathway, using a radiofrequency
ablation catheter. During the ablation, unexpected movement
may result in catheter dislodgment and damage to normal conducting
tissue; therefore, general anesthesia is usually required in younger children.
Anesthetic agents and techniques should be chosen to maintain
circulating catecholamines and avoid suppression of arrhythmogenesis,
for identification of the aberrant pathway. [Miller,
378. @Describe the 4 steps to treating hyperkalemia
in the neonate
Emergent treatment of hyperkalemia in the neonate centers around antagonizing
the cardiac effects of excess potassium-administer calcium as
calcium chloride (0.1-0.3 mL/kg of 10% solution) or calcium gluconate
(0.3-1.0 mLlkg 10% solution) over 3-5 minutes. Return potassium to the
intracellular space by correcting acidosis through sodium bicarbonate, mild hyperventilation. and a ~-agonist.
Maintain potassium
in the intracellular space by glucose + insulin infusion, 0.5-1.0
g/kg glucose with 0.1 U/kg insulin over 30-60 minutes). Remove wholebody
potassium burden by Kayexalate or dialysis and correct the underlying
etiology. [Cote. PAle. 4''- 2009 ppl72-173J
379. ®An infant has a life-threatening succinylcholineinduced hyperkalemia: what is Lhe definitive treatment?
The definitive treatment of succinylcholine-induced hyperkalemia is IV
calcium (10 mg/kg calcium chloride or 30 mg/kg calcium gluconate or
morc), This restores the gap between the resting membrane potential of
the cardiac cells and the threshold potential for depolarization. Repeated
doses of calcium must be administered together with cardiopulmonary
resuscitation, epinephrine, sodium bicarbonate, glucose and insulin. and
hyperventilation until the arrhythmias abate. [Cote. PAle. 4,h 2009
380. "Which maternal hemodynamic parameter
shows the greatest decrease during normal gestation?
During normal gestation, the greatest decrease in a hemodynamic parameter
occurs in the systemic vascular resistance (-20% SVR). [Chestnut,
Obstetric Anesthesia, 3rd ed., 2004, p18t
381. Which maternal hemodynamic parameter
shows the greatest increase during normal gestation?
During normal gestation, the greatest increase in a hemodynamic parameter
occurs in the cardiac output (+50% CO).
382. Identify 3 maternal physiological disturbances
that pose the greatest risk to the fetus
The greatest risk to the fetus occurs following maternal catastrophes
involving (1) severe hypoxia, (2) hypotension, and (3) acidosis. [Chestnut
383. What is the most serious fetal risk associated
with maternal surgery during pregnancy?
The most serious fetal risk associated with maternal surgery during pregnancy
is that of uterine asphyxia
384. Describe plasma cholinesterase (pseudocholinesterase)
changes in the pregnant patient
Plasma cholinesterase (pseudocholinesterase) levels will decrease by 24%
before delivery and decrease further (to 33% less) by 3 days postpartum.
[Hughes, Anes.for OB, 41h ed., 2002, p13]
385. After parturition, how long does it take
for plasma cholinesterase (pseudocholinesterase)
levels to return to normal?
Plasma cholinesterase (pseudocholinesterase) levels will return to normal
levels in 2-6 weeks postpartum
386. @)How does minute ventilation change
during pregnancy?
Minute ventilation increases by up to 45% during pregnancy. [Barash, DB
Anes .. 4th. 2009
387. @)What respiratory parameter changes most
to increase minute ventilation during pregnancy?
What physiological factors prompt
the increase in minute ventilation during pregnancy?
During pregnancy, resting minute ventilation increases (up to 45%) owing
primarily to an increase in tidal volume, with minimal, if any, change
in inspiratory rate and pattern. The rise in minute ventilation results from
hormonal changes (increased progesterone) and increased C02 production.
Progesterone acts as a direct respiratory stimulant and the progesteroneinduced increase in chemoreceptor sensitivity results in a steeper
and leftward shifted C02 ventilatory response curve
388. @)What is the earliest sign of magnesium
toxicity?
Clinically, the therapeutic effects of magnesium therapy are estimated by
the response to deep tendon reflexes. Marked depression of deep tendon
reflexes is an indication of impending magnesium toxicity. At therapeutic
magnesium levels (4-6 mEq/L), lethargy, nausea & vomiting, and facial
flushing may occur. At magnesium levels greater than 6 mEq/L, loss of
deep tendon reflexes and hypotension ensue. [Miller
389. @)State the loading and maintenance doses
of magnesium sulfate administered for
seizure prophylaxis in pregnancy-induced hypertension?
For seizure prophylaxiS in pregnancy-induced hypertension (preeclampsia),
magnesium sulfate is administered at a loading dose of 4-6 g over
20-30 minutes, followed by a maintenance dose of 1-2 glhr, continued
for up to 24 hours postpartum. [Barash
390. @l What specific changes are often seen in
the ECG when magnesium levels reach 10 meq/L? At magnesium levels of 10 mEq/L.
prolonged P-Q intervals and widened
QRS complexes may be observed. Asys tole occurs at 20 mEq/L. [Yao. Yao
&Artllsios POPM. 6e. 2008 pp9171
391. v'Does magnesium sulfate cross the placen ta?
What effects can magnesium sulfate have on the fetus?
Magnesium sulfate may cross the placenta and potentially cause hypermagnesem
ia in the fetus. Hypermagnesemia in the felus results in loss of
beat-to-beat variability in fetal heart rate, hypo reflexia, muscle weakness.
and respiratory depreSSion (apnea ).
392. ,.,Identify the drugs that are compalible
with the mother who is breast-feeding her infant
Most drugs are safe during lactation. Typically only 1% to 2% of lhe maternal
dose appears in breast milk. Lithium and ergotamine are best
avoided during lactation. [Chestnut
393. The parturient has received a neuraxial
opioid and is experiencing nausea and vomiting.
Which drug is particularly effective
for opioid-induced nausea and vomiting in laboring women?
Ondansetron (Zofran) is effective for the treatment of opioid-induced
nausea and vomiting in laboring women, and it also has few side effects.
[Chestnut, DB Anes .. 3rd. 2004
394. The parturient has received a neuraxial
opioid and is experiencing nausea and vomiting.
Which drug is effective for opioidinduced
nausea in laboring women, but has but has the most significant SE?
Droperidol is effective for the treatment of nausea in laboring women, but
it has significant side-effects, namely dysphoria, akathisia (an unpleasant
t
sensation of "inner restlessness" accompanied by the inability to sit still),
and oculogyric crisis. Furthermore, the FDA has issued a "black box"
warning because of the concern that the administration of droperidol may
result in an increased risk of cardiac arrhythmias
395. Identify the most common cause of anesthesiarelated maternal mortality on the obese parturient
The most common anesthesia-related cause of maternal mortality in the
obese parturient is airway complications
396. ,*,What is the appropriate positioning for
the parturient with amniotic fluid embolism
if the fetus has not yet been delivered?
For the parturient with amniotic fluid embolism (AFE) from whom the
fetus has not been delivered, left uterine displacement is appropriate,
along with slight head-up position, with left lateral tilt of at least 15 degrees.
397. ,*,Identify 5 signs and symptoms of venous
air embolism in the pregnant patient.
Signs and symptoms of venous air embolism in the pregnant patient are
(1) mill-wheel murmur detected over the pericardium, (2) chest pain, (3)
dyspnea, (4) decreased end-tidal CO2, and (5) elevated central venous
pressure. Late signs of venous air embolism are hypotension, tachycardia.
and cardiac dysrhythmias.
398. ,*,The obstetric patient develops a venous
air embolism-in what position will you
place the parturient?
The parturient who develops a venous air embolism (incidence as high as
9596) should be placed in a slight anti-Trendelenburg position with leftlateral
tilt of IS. This position increases the likelihood of trapping air in
the right atrium, from which it can be aspirated via a central venous
catheter.
399. Your patient has mitral stenosis and is
being prepared for an emergent cesarean
section. The patient has not been adequately
hydrated and hypotension is a concernwhich
anesthetic technique will you use
A general anesthetic would be the technique of choice for emergent cesarean
section when hypotension is a major concern. Although regional and
neuraxial techniques are viable options, hypotension is more common
with these techniques, compared to general anesthesia. Hypotension is
most common with a spinal anesthetic, less common with epidural anesthetics,
and modestly less common with a regional technique; a general
anesthetic is associated with the least likelihood of hypotension
400. A parturient has ges tational diabe tes
mellitus and is hyperglycemic on admission
for labor and delivery. Will her infant be
normoglycemic, hypoglycemic, or hyperglycemic? Why?
Neonatal hypoglycemia occurs in 5% to 12% of cases of pregestational and
gestational diabetes mellitus (OM). The neonatal hypoglycemia is pre·
sumed to result from sustained fetal hyperinsulinemia that develops in
response to chronic intrauterine hyperglycemia. Decreased fetal oxygen
secondary La uncontrolled maternal OM may also promote hypoglycemia
in the fetus and newborn. [Chestnut, OB
401. 'Elderly patients have changes in autonomic
function referred to as physiologic
beta blockade. Identify two cellular changes
that explain the blunted ~-receptor response
in the geriatric patient. What two cardiovascular
responses are altered due to the
blunted ~-receptor response?
Decreased ~-receptor responsiveness is secondary to both decreased
receptor affinity and alterations in signal transduction (specifically,
decreased intracellular cyclic AMP). Decreased ~-receptor responsiveness
assumes functional importance when increased flow demands are placed
on the heart. Normally, ~-receptor-mediated mechanisms act to increase
the heart rate, venous return, and systolic arterial pressure while preserving
preload reserve. [n contrast, the attenuated ~-receptor response in the
elderly during exercise/stress is associated with (1) decreased maximal
heart rate and (2) decreased peak ejection fraction. Such decreases cause
the increased peripheral flow demand to be met primarily by preload
reserve, thereby making the heart more susceptible to cardiac failure.
402. What two important changes in the autonomic
nervous system (ANS) take place with aging?
The two most important changes in the autonomic nervous system with
aging are a decrease in response to ~-receptor stimulation and an increase
in sympathetic nervous system activity.
403. What is tumescent liposuction?
"Tumescent" means distended, especially by fluids or gas. and comes
from the same Latin root as "tumor." During tumescent liposuction. a
combination of IV fluid, dilute lidocaine 0.05% to O. I %, and dilute epinephrine
I: 1 ,000,000 (collectively called the wetting solution) is used to
emulsify fa t, provide anesthesia, and create hemostasis during liposuction
404. Identify the ratio of wetting solution to
volume of fat 10 be removed for tumescent
liposuction. What is the anesthetic concern with this ratio?
For tumescent liposuction, a ratio of 1 mL of wetting solution to each mL
of fat to be removed is commonly employed. With liposuction volumes
approaching the 4000- to 5000-mL range (or greater), a chief concern is
fluid volume overload. Fluid volume overload may promote hypoxemia,
hypertensi011, andlor postoperative pulmonary edema. !Jaffe & Samuels.
Anesthesiologist's Manual of Surgical Procedures
405. What accounts for up to 25% of deaths
during liposuction?
PE accounts for 25%
406. @)Clinical improvement follOwing an epidural
steroid injection correlates with three
(3) pathophysiologic findings at the nerve
root. What are these 3 findings?
Epidural steroid injection provides relief from acute radicular pain when
the nerve root(s} exhibits: (1) edema, (2) inflammation, and (3) increased
levels of phospholipase A2 (PLA2) expression.
407. @)Which nerve fibers appear to be affected
by epidural steroids?
Local applicatio~_ of methylprednisolone was found to reversibly block
transmission in the unmyelinated C-fibers. but not in AfJfibers.{Cousins
& Bridenbough. Neural Blockade. 4th. 2009 pp 1074
408. @What procedure is generally effective for
symptomatic relief of acute radieulopathy( nerve root compression)?
Epidural steroid inj ections are effective for relief of pain associated with
acute radiculopathy (nerve root compression). [Morgan, et aI., Clin.
409. @With respect to the onset of acute radiculopathy.
what appears to be the optimal time
frame for epidural steroid injection? For
how long can an epidural steroid inj ection
be expected to provide pain relief from acute radiculopathy?
Epidural steroid injections are most effective when given within 2 weeks
of onset ofpaitl and do not appear to provide long-term pain relief beyond
3 months
410. @Identify the two most commonly used
steroidal agents and their dosing for epidural
steroid injections. In what kind of mixture is the steroid often injected?
The two most commonly used agents for epidural steroid injection are
methylprednisone acetate (Depo-Medrol) 40-120 mg. and triamcinolone
diacetate (Aristocort), 40-80 mg. The steroid is injected either alone, with
a saline diluent, or in mixture with a local anesthetic. [Morgan, et aL, ClilL
Alles/h .. 4e. 2006 pp404; Cousins. Neural Blockade
411. @What advantagesdoa local anesthetic and
steroid mixture provide (or an epidural
steroid injection? What are the disadvantages
of administering the local anesthetic in combination with a steroid?
A mixture of local anesthetic and steroid for the epidural injection may be
helpful if the patient has muscle spasm and the local anesthetic provides
immediate pain relief until the steroid's anti-inflammatory effects take
place (12-48 h). Injection of a local anesthetic carries the risks of intra thecal,
subdural, and intravascular complications, such as hypotension,
arrhythmia. and seizure
412. Neurolytic blocks arc not permanent
because of the agents used to temporarily
destroy nerve fibers or neural ganglia. Identify
the 2 agents most commonly used to
perform neurolytic block and the appropriate concentration for each agent
Temporary destruction of nerve fibers or ganglia is typically accomplished
by injection of alcohol (50-100%) or phenol (6- 12%). Ethyl alcohol
causes temporary destruction of nerve fibers or ganglia by causing
extraction of membrane phospholipids and precipitation of membrane
proteins. Phenol appears to cause temporary des truction of neural tissue
by coagulation of proteins. [Morgan
413. @Ust three (3) approaches to the epidural
space ror an epidural steroid inj ec tion. What
is the recommended volume for injection
with each route?
The epidural space can be approached through the interlaminar space
(med ian or paramedian), the int ervertebral foramen (lransforaminai,
"selective nerve block"), or the sacral hiatus (caudal). When using a caudal
approach, 20 to 25 mL or a solution has been recommended to assure
epidural spread cephalad to the desired level. When using a lumbar inlerlaminar
approach, a volume of 5 to 10m L has been recommended to
reach those areas most commonly involved in the lumbar reg ion. A volume
of2-3 mL is lIsed for the transforaminal approach
414. ®Which of the three approaches to an
epidural steroid injection requires the use of
radiographic imaging for needle placement?
The transforaminal ("selective nerve block", intervertebral) approach
requires the use of radiographic imaging ifit is to proceed with safety.
415. What is the primary indication for a
neurolytic block?
Neurolytic blocks are indicated for patients with severe, intractable cancer
pain. [Morgan
416. Are neurolytic blocks permanent or temporary?
Neurolytic blocks are not permanent. Neurolytic blocks may last from 2-6
months.
417. vWhat procedure should be done prior to a neurolytic block?
At least one diagnostic block with local anesthetic should be done before
considering any neurolytic technique. This serves to confIrm the pain
pathway(s) involved and to determine the potential efficacy of the neurolytic block
418. @)What is the most effective measure for
pain associated with pancreatic cancer?
Celiac plexus block with alcohol or phenol is the most effective intervention
for treating pain associated with pancreatic cancer
419. Identify the 4 most common neurolytic
blocks performed in cancer patients with intractable pain
The 4 most commonly employed neurolytic blocks in cancer patients with
intractable pain are: (1) celiac plexus; (2) lumbar sympathetic chain; (3)
hypogastric plexus; and, (4) ganglion impar (retroperitoneal plexus).
Neurolytic techniques are sometimes used for somatic or cranial nerves or
even neuraxial blocks.
420. @)What nerves when blocked may provide
relief from cluster headaches? Block or
ablation of which nerve ganglion may provide
relief from cluster headaches?
The greater occipital nerve block is commonly used for primary headache
syndromes; for chronic syndromes, the anterior region involving the
trigeminal nerve is also blocked. It has been reported for use with cervicogenic
headache, OCcipital neuralgia, migraine, and cluster headache.
Sphenopalatine ganglion neurolytic block can be used to treat headache
and facial pain.
421. List two exceptions to the statute oflimitations
for ftling a lawsuit claiming negligence
Two exceptions to the statute of limitations for ftling a lawsuit are: (1) the
plaintiff is under a disability which keeps the plaintiff from bringing the
suit (e.g., children, persons under legal guardianship), and (2) the plaintiff
may not have been able to discover that there was an injury caused by
negligence before the statute oflimitations expired. Note: the statue of
limitations varies by state, by nature of the case and by the circumstances
of the case.
422. @)What is the most common cause of malpractice
claims against anesthesiologists?
Tooth damage is the most common cause of malpractice claims against
Anesthesiologists
423. Which amendment to the United States
Constitution gives the states the right to
enact laws to protect the health and safety of their citizens?
The Tenth Amendment to the United States Constitution reads: "The
powers not delegated to the Unites States by the Constitution, nor prohibited
by it to the States, are reserved to the states, respectively, or to the
people." The Tenth Amendment is the source of the states "police power"
or right to regulate the public health, welfare, and safety (Dent v West
Virginia, 1889
424. List the 6 elements of informed consent
The six elements of information that are required for consent are: (1) the
patients diagnosis, (2) the general nature and purpose of the anticipated
procedure, (3) the risks and consequences involved, (4) the prospects of
success, (5) the prognosis if the procedure is not performed, and (6) the
alternative methods of treatment available, if any. [Waugaman, Principles
and Practice
425. What principle mitigates the information
provided to obtain patient consent?
The duty to disclose is measured by the amount of knowledge the patient
needs. [Waugaman
426. What four elements must be proved when
applying the doctrine of res ipsa loquitur
In order to apply the doctrine of res ipsa loquitur ("the thing speaks for
itself), the following four elements must be proved: (I) the injury is of a
kind that typically would not occur in the absence of negligence, (2) the
injury must be caused by something under the exclusive control of the
anesthesiologist, (3) the injury must not be attributable to any contribution
on the part of the patient. and (4) the evidence for the explanation of
events must be more accessible to the anesthesiologist than to the patient
427. What is amicus curiae?
Amicus curiae literally is "friend of the court." During the appeal process,
an appellate court permits persons who are not parties to the case to
provide relevant information to the appellate court on the law to be applied.
The procedure used to provide this relevant information is a brief
amicus curiae. a brief filed as a "friend of the court."
428. @List four characteristics of research
Research can assume many different forms. Research should be valid.
both internally and externally. Research must be reliable, which refers to
th e extent to which data coll ection. analysis, and interpretation are
consistent
and to which the research can be replicated. And finally. research
must be systematic. [
429. @ldentifytheeight(8) stages of the research
process.
The research process is defined as consisting of the following eight distinct
stages: (I ) identification of the problem; (2) review of the relevant
knowledge and literature; (3) formulation of the hypothesis or research
question; (4) development of an approach for tes ting the hypothes is; (5)
execution of the research plan; (6) analysis and interpretation of the data;
(7) dissemination of the findings to interested colleagues; and (8) evaluation
of the resea rch report. [Nagelhout
430. @Oefine"hypothesis." What does a hypothes
is establish?
In its most elemental form. a hypothes is is either a proposition of the
solution to a problem or a stated relationship among variables. A hypothesis
establishes and defines the independent variable (the variable to be
manipulated or is presumed to influence the outcome) and the dependent
variable (the outcome that is dependent upon the independent variable).
The hypothes is is declara tive in structure
431. @State three (3) forms a hypothesis may
take.
A hypothes is may be a directional hypothesis. A direc tional hypothesis will
include the words less or more. A notldirectional hypothesis states there is
a difference wi thout specifying the direction of the difference. The third
type of hypothes is is the null hypothesis. which states there is tlO difference
in the relat ionship or proposed solutions to the problem
432. @lThere are many ways to class ify research
methods. One of the more popular ca tegori zations
is to separate the methods into ob servaliorlal
and experimental (interve1Itio1/ al)
sludies. Briefly describe each method
Observational studies are those in which data is gathered without performing
and specific intervention affec ting the ass ignment of groups or
effects on group members. In an experimental study, subjects are assigned
to groups, an intervention(s) is performed. and attempts are made
to eliminate bias and confounding va riables before the data are collected
433. @Observational studies rna)' be classified as
case-se ries, case-control. cross-sectional, or
cohort studies. Describe a case-series.
In a simple case-series, the author describes some interes ting or intriguing
observations that occurred for a small number of patients. There
are no co ntrol subjects. thu s the case-study does not have the nature of
"proving" something. but often leads to a hypoth es is and subsequent
invest iga tion
434. @)Howdocase-control and cohort stud ies differ?
Cohort and case-control studies are called longitudinal studies because
they are involve an ex tended period of time defin ed by point when the
study begins and the paint when it ends. A case-cont rol sludy begin "at the end"
with the presence or absence of an outcome and then looks
backward in time to try to detect possible causes or risk factors that may
explain the outcome. Therefore, a case-control study is a retrospective
study that asks, "What happened?" In a cohort study, the researchers
select group of people who have something in common, say a risk factor,
and then monitor the cohort forward in time. A cohort study asks, "What
will happen?" and thus is a prospective study
435. @What is "bias" in a research method?
Bias is a systematic effect in the study that produces an error on our interpretation
of the results. Several types of bias exist; some of the more
common biases are: selection bias, confounding bias, and measurement
bias.
436. ® Describe selection bias.
Selection bias occurs when two groups are compared with respect to some
variable without acknowledging or realizing that the groups are different
in other important ways
437. @Define confounding bias.
Confounding bias occurs when multiple variables are intertwined so that
although we may assume the variable under study is important, the truth
is that the confounding variable may be more imp
438. ®Describe measurement bias
Measurement bias occurs if the methods used for making measurements
when comparing different groups have different scales or sensitivities.
Measurement bias may be avoided in a blinded study
439. @What does the term blinding refer to?
What may be avoided by doing a blinded study?
The term blinding (or masking) refers to the process of controlling for
obvious and occult biases arising from the subjects' or researchers' reaction
to what is taking place. In a blinded (or masked) study, measurement
bias may be avoided if the person performing the measurement does not
know which group is being measured. This is called a single-blind study.
In a double-blind study, neither the researcher nor the subject is aware of
which treatment or manipulation the subject is receiving. In either
blinded study, measurement bias is avoided
440. ®What type of research design method is
the "gold standard" and why is this so? What
are the disadvantages to this "gold standard design”?
The idealized "gold standard" research design in medical research is the
randomized clinical trial (RCT). The ReT is ideal because: (I) the subjects
are randomly assigned to the research groups, minimizing selection bias;
(2) the study is prospective (looking forward in time); (3) the dependent
variable is measured; (4) it provides the greatest justification for concluding
causality; and (5) it is subject to the least number of biases. The greatest
obstacles to RCTs are the great expense, efforts needed, and duration
of the study. To minimize and overcome these disadvantages, RCTs are
often carried out as multi-center trials. [Nagelhout, NA. 4th. 2009 pp55;
B
441. @>As with research study design methods,
there are many ways to categorize types of
data and measurements. Nagelhout categorizes
data in 4 categories. List the four categories
of measurement/data types
The four levels or degrees of measurement or data types are: nominal,
ordinal, interval, and ratio. For reference, one of the other popular categorization
of measurements is: nominal, ordinal, and numerical. Nominal
and ordinal measurements are often called qualitative observations, whereas
interval and ratio measurements are called quantitative observations.
Both interval and ratio measurements are continuous in nature
442. @>Give the characteristics of nominal measurements
and some examples of nominal data
Nominal scales are used for the simplest types of data that fit into categories.
Nominal measurements simply identify the data. If there are only two
categories of data, for example male and female, the observations are
binary or dichotomous. An example of observations with more than two
categories would be blood types (A, B, AB, 0) and eye color
443. @>Give the characteristics of nominal measurements
and some examples of nominal data
Nominal scales are used for the simplest types of data that fit into categories.
Nominal measurements simply identify the data. If there are only two
categories of data, for example male and female, the observations are
binary or dichotomous. An example of observations with more than two
categories would be blood types (A, B, AB, 0) and eye color. [Nagelhout,
NA. 4th. 2009 pp55; Dawson & Trapp, Basic Bi
444. <i>Give the characteristics of ordinal measurements
and some examples of ordinal data
With ordinal measurements, observations are still classified by categories,
but some observations may have more or are greater than other observations,
and thus are ordered or ranked. Examples of ordinal data include
order of race finish (l st, 2nd, 3fd, etc), pain scores, and the ASA classification
scheme (ASA Class I, ASA Class II, etc.).
445. Give the characteristics ofinterval measurements
and some examples of interval data
Interval observations measure the quantity of something for which the
differences between the numbers have meaning on a numerical scale built
upon equally spaced intervals. Technically, interval data does not have an
absolute zero point on the scale. Examples are temperature on the Fahrenheit
or Celsius scales, calendar years, or the IQ scale. The distance
(interval) between adjacent measurements is meaningful and quantifiable,
not simply "more" or "less."
446. @>Give the characteristics of ratio measurements
and some examples of ratio data.
Ratio measurements are quantitative, numerical observations that can be
ordered and equally spaced, but which are based upon a numerical scale
that has an absolute zero point. Examples of ratio data are the temperature
on the Kelvin scale (absolute temperature), blood pressure, distance,
and height. [Nagelhout
447. @What is operationalization?
Operationalization is the process of making the characteristics inherent in
a given variable, condition. or process clear and familiar to others. For
example, if a study examined critically ill patients it would be essential to
operationalize the term "critically ill patients" in order to clearly delineate
the term so that the research might be replicated without change
448. @)List three different classes of statistical
techniques used to analyze and interpret research data
Once the observations have been collected, they are often categorized and
described by descriptive statistical techniques. If a relationship between
data has been hypothesized, correlational statistical techniques may be
used to describe the extent to which two (or more) variables are related to
each other or for quantifying the degree of that relationship. Finally,
inferential statistical techniques provide a set of procedures that allow the
researcher to infer that the events observed in the sample will also occur
in the larger unobserved population from which the sample was obtained.
449. @)What are the population and the sample in statistical terms?
The population refers to any target group of things (animate or inanimate)
in which there is interest. The population is the entire collection of
observations or subjects that have something in common and to which
conclusions are inferred. A sample is a subset of the target population.
Samples are taken because of the impossibility of observing the entire
population; it is generally not affordable, convenient, or practical to examine
more than a relatively small fraction of the population
450. @)What is a "distribution"? Describe the
Normal distribution.
The group or set of all the observations of a variable along with the frequency
of their occurrence and placement of the values is called the distribution
of the variable. A distribution may be based on empirical observations
or may be a theoretical probability distribution that is defined by
an algebraic equation. The most important distribution is the Normal
distribution, also called the Gaussian or bell-curve distribution
451. @)Why is the normal distribution so important
the biological and medical research methods?
The Normal distribution is important because it has been empirically
noted that when a biologic variable is sampled repeatedly, the pattern of
the numbers plotted as a histogram resembles the normal curve; thus,
most biologic data are said to follow or to obey a normal distribution.
Equally important, a mathematical theorem (the central limit theorem)
allows the use of the assumption of Normality for certain purposes, even if
the population is not Normally distributed
452. @)List the three descriptive statistics that
specify the central tendency, or middle, of numerical data
The median is the center or middle data point if the data can be ordered
(ranked) from smallest to largest. The median is the point at which half
the observations are smaller, half are larger. The mode is the most frequently
occurring value. The mean is the arithmetic average of the numericalobservations
in a sample. The mean is symbolized by x-, called Xbar.
453. ~On addition to describing the central
tendency of the data distribution, we also
need to characterize the spread or variability
of a data sample. What two measures describe
the spread or variability of data (hint: variability = deviation)?
The spread, dispersion, or variability of data is described by the range and
the variance eo standard deviation. The range is simplest the difference
between the largest and smallest observation. The standard deviation is a
measure of the spread of the data about their mean. The standard deviation
measures the "average" spread of the observations about the mean.
The variance is the square of the standard deviation and its mathematical
derivation and rationale is beyond the scope of this resource
454. Inferential statistical techniques are either
parametric or nonparametric. Define these terms
When data follow a normal distribution, the methods of parametric statistics
can be used. The term parametric refers the ability to describe the
distribution with a specific set of values, or parameters. For the Normal
distribution, only two parameters are required to define and describe the
distribution: the mean and the standard deviation. If it is not possible to
describe the data with a set of parameters, nonparametric statistical methods
are required.
455. @)What is the first question to ask in choosing
a statistical test?
The first question to ask in considering the choice of a statistical test is to
decide whether statistical methods that assume a Normal distribution
(parametric) are appropriate, or whether nonparametric methods are
needed (data is not Normally distributed
456. ®What is the second question to ask in
choosing the appropriate statistical test?
The second question to ask when choosing between statistical tests is
"how many groups are being compared?" There may be one group, two
groups, or multiple groups to characterize
457. ®What is the third question to ask in choosing
the appropriate statistical test, based
upon two or more groups?
The third question to ask in choosing a statistical test is "are the data in
the groups paired or unpaired?" A key to answering this question is to ask
"were the same individuals studied before and after some intervention or
condition?" If the answer is "yes, the same individuals were studied before
and after an intervention" then these are paired data groups not independent groups
458. ®Which statistical test compares the difference
between the means of Normally distributed
interval or ratio data from two independent groupd
The unpaired (two-sample) Student's t test is used to compare the difference
between the means of two independent groups, provided the observations
are Normally distributed interval measurements. [Nagelhout, NA.
41h. 2009 pp58-59;
459. @)Describe the appropriate application of
the paired Student's t test.
Given Normally distributed interval or ratio data, the paired t test (also
called a t test, dependent samples) evaluates the difference between dependent,
paired sample (for example pretreatment and posttreatment)
outcomes.
460. @>Given nonparametric nominal data from
two or more independent samples (groups),
which statistical test evaluates the difference
between observed and expected frequencies?
The Chi-squared analysis of contingency tables evaluates the difference
between observed and expected frequencies from nominal or ordinal data
that are not necessarily Normally distributed. [Nagelhout, NA. 41h. 2009
pp58-59; Miller, Miller's Anesthesia, 71h
461. @>Which nonparametric test is the equivalent
of the unpaired t test for nonparametric ordinal data?
The Mann-Whitney rank sum test tells whether medians between two
independent nonparametric groups of ordinal data are different. After
individual observations are ranked, the ranks are analyzed just as though .
they were the original data. The various incarnations of the general rank
sum test are often used by researches in the health field for nonparametric
data. [Nagelhout, NA. 41h.
462. @>Which parametric test evaluates the difference
among the means of interval or ratio
data from more than two independent
groups or more than one independent variable?
An analysis of variance (ANOV A) tests the difference among the means of
more than two independent groups or more than one independent variable
given Normally distributed interval or ratio data
463. >What is the appropriate statistical test to
determine whether one variable x (the independent
variable) predicts the outcome of
another variable y (the dependent variable).
Simple linear regression evaluates the association between two parametric,
numeric variables. Linear regression produces an equation in the form of
y = mx + b that allows predication of the outcome variable y (the dependent
variable) given the predictor variable x (the independent variable).
464. ®Define "standard of ca re."
The standard of care is the conduct and skill of a prudent practitioner that
can be expected by a reasonable patient. Standard of ca re is also defined
as reasonable ca re by a professional. (Nagelhout). Standa rd of ca re is a
very important medicolegal concept because a bad medical result due to
failu re to meet the standard of ca re is malpractice
465. ,..-The National Practitioner Data Bank
(NPDB) requires input (information) from what 5 sources?
The National Practitioner Data Bank (NPDB) requires input from five
sources: (1) medical malpractice payments, (2) license actions by medical
boards, (3) professional review or clinical privilege actions taken by hospitals
and other health care entities (including professional societies), (4)
actions taken by the Drug Enforcement Agency (DEA), and (5) Medicare/
Medicaid exclusions.
466. @)How is the standard of care established?
What two sources are typically consulted to
establish the standard of care?
Ultimately, the standard of care is what a jury says it is (Barash). There
are two main sources of information as to exactly what is the expected
standard of care. Traditionally, the beliefs offered by expert witnesses in
medical liability lawsuits regarding what is actually being done in real life
(de facto standards of care) were the main input juries had in deciding
what was reasonable to expect from the defendant. The second, much
more objective, source for defining certain component parts of the standard
of care is the published standards of care, guidelines, practice parameters,
and protocols now becoming more common. These serve as hard
evidence of what can be reasonably expected of practitioners and can
make it easier for a jury evaluating whether a malpractice defendant failed
to meet the applicable standard of care
467. @)What agency sets and enforces quality
standards for ambulatory surgical facilities?
Quality standards are set and enforced either by government regulation,
through a licensing process, or by accreditation by private organizations
such as the Accreditation Association for Ambulatory Health Care
(AAAHC). The AAAHC is an independent accreditation organization
whose principle activities are to develop standards. conduct surveys, and
confer accreditation on ambulatory health care providers. In the United
States and Canada, hospital-based ambulatory surgical facilities receive
accreditation through The Joint Commission (formerly JCAHO). [Miller,
Miller's Anesthesia, 7th. 2009 pp2421)
468. @)What are the first two actions to take in
an ainvay fire? What are the next actions?
The first action in an airway fire is to simultaneously stop ventilation and
remove the endotracheal lube, followed immediately by turning
off/disconnecti'lg the oxygen. The sequence of subsequent actions varies
(different references give slightly different orders) but includes: pour
saline into airway; remove burning materials; mask ventilation and reintubation;
diagnose the injury, treat by bronchoscopy and laryngoscopy;
administer short-term steroids; monitor the patient for at least 24 hours;
and. administer an tibiotics and provide ventilatory support as necessary