antagonism (e.g., prochlorperazine) are useful antiemetics, with no effect on gastric
4. B. Atelectasis likely occurs in all patients who undergo general anesthesia, in
particular those postabdominal surgeries. Changes of microatelectasis develop
routinely and do not significantly delay discharge for most patients despite the
relative state of hypoxia (decreased PaO2
). Deep breathing, use of an incentive
spirometer, early mobilization, and adequate pain control are all measures used to
expand lung volumes and promote improved oxygenation.
5. A. Postsurgical atelectasis is treated by physiotherapy, focusing on deep
breathing while encouraging coughing. An incentive spirometer is often used to
promote full expansion of the lungs. Ambulation is also highly encouraged to
improve lung inflation. These measures are considered first-line options for his
presumed microatelectasis. In the smoker, coughing will also clear the airways of
mucous to improve aeration. Doxapram stimulates chemoreceptors in the carotid
bodies, which in turn stimulates the respiratory center in the brain stem to increase
tidal volume and respiratory rate.
6. A. Initial management involves the recognition of a possible aspiration event
when there are visible gastric contents in the oropharynx. Once diagnosis is
suspected, the patient should be placed in Trendelenburg position to limit pulmonary
contamination, followed by suctioning of the oropharynx. Empirical antibiotic therapy
is strongly discouraged unless it is apparent that the patient has developed a
subsequent pneumonia. Corticosteroids should not be given prophylactically, as there
is no evidence to support this practice.
7. B. Gastrointestinal secretions, including diarrhea and intestinal fistulas, are rich
in bicarbonate and, therefore, losses will cause a metabolic acidosis. However,
respiratory compensation for metabolic processes will occur almost immediately by
increasing ventilation to blow off CO2
to reduce the acidosis, effecting change in as
quick as 15 to 30 minutes. Therefore, one would expect ABG findings of a metabolic
acidosis with full respiratory compensation.
8. A. The ACT enables one to monitor the anticoagulant effect of unfractionated
heparin. ACT prolongation can also indicate coagulation-factor deficiency, severe
thrombocytopenia, or severe platelet dysfunction. The ACT is sensitive to a
deficiency or dysfunction of all the clotting factors (except factor VII)—indicating
problems with the intrinsic or common pathways. Factor level must be less than 5%
9. A. An acute hemolytic transfusion reaction is associated with hemolysis of
transfused blood, usually related to ABO incompatibility with associated
hemoglobinuria. Pulmonary leukoagglutinin reaction is related to the presence of
antileukocyte antibodies in donor plasma leading to transfusion-related acute lung
10. B. Malnourished surgical patients are at greater risk for postoperative morbidity
and mortality compared to a well-nourished patient undergoing similar operations for
similar indications. However, providing TPN to the malnourished patient in the
perioperative period carries its own inherent risks, such as greater risk of infection,
hyperglycemia, and electrolyte abnormalities.
11. D. For those on TPN, the anesthesiologist must monitor blood glucose levels
meticulously to avoid hypo- or hyperglycemia. Hyperosmolar, nonketotic,
hyperglycemic coma has been reported in patients who fail to regain consciousness
12. B. Ensuring the presence of normal serum phosphate levels in the patient receiving
TPN is essential, as hypophosphatemia has been associated with acute respiratory
failure due to profound areflexic muscle weakness.
13. D. The most critical element to safe perioperative care of the pheochromocytoma
patient is adequate preoperative blockade against the effects of the circulating
catecholamines. The main goals of preoperative blockade are to normalize blood
pressure and heart rate, restore volume depletion, and prevent surgery-induced
catecholamine storm. A sign of adequate α-blockade is the development of nasal
congestion due to smooth-muscle relaxation of nasal mucosal arterioles.
14. A. Switching from isoflurane to sevoflurane is not an appropriate method to treat
the catecholamine storm, which can occur during direct surgical manipulation of the
tumor. An α-blocker, vasodilator, and lidocaine are appropriate options to counter
the effects of catecholamine storm.
15. A. Sympathetic preganglionic fibers originate in the intermediolateral cell column
of the spinal cord from T1 to L2. Cardiac innervation is principally via sympathetic
fibers from T1 to T4. As such, high thoracic blockade up to T2 will block the
cardioaccelerator nerves, leading to bradycardia and hypotension. The respiratory
system is usually unaffected, as diaphragmatic breathing alone can maintain
relatively normal arterial blood gases. However, patients may feel unable to breath
and are often unable to cough effectively.
16. A. The pharmacokinetics of many nondepolarizing muscle relaxants in the presence
of cholestasis and obstructive jaundice may be altered. The prolonged duration of
action likely results from both inhibition of hepatic uptake by the accumulated bile
salts and a general deterioration of liver transport function. Succinylcholine,
atracurium, and cis-atracurium have theoretical advantages because their elimination
occurs via plasma cholinesterases and Hofmann degradation, respectively, mostly
independent of renal or hepatic function.
17. C. Postoperative liver dysfunction is common, but is generally mild and
asymptomatic (Table 14-2). Mild transient increases in serum levels of liver enzymes
(SGOT/SGPT) are often seen within hours of surgery, but rarely persist >2 days.
Subclinical hepatocellular injury can occur in up to 50% of those receiving an
inhaled anesthetic with halothane. Though volatile anesthetics are often implicated as
the cause of postoperative jaundice, there are many other causes to consider. A
surgical cause is likely if the operation involved the liver or biliary tract. Drugs,
including antibiotics, and other metabolic or infectious causes must also be ruled out.
Table 14-2 Postoperative Liver Dysfunction—Causes and Differentiation.
18. B. Chronic liver disease may interfere with the metabolism of drugs due to
decreased number of functional hepatocytes or decreased hepatic blood flow that
typically accompanies cirrhosis of the liver. Prolonged elimination half-life times for
morphine, diazepam, lidocaine, pancuronium, and, to a lesser degree, vecuronium
have been demonstrated in this population. Cirrhotic patients will require a larger
initial dose of pancuronium due to increased volume of distribution for this
hydrophilic agent with smaller maintenance doses for prolonged duration of action.
Pancuronium has slight vagolytic activity resulting in increased heart rate and cardiac
output. Mivacurium and atracurium are associated with histamine release.
19. B. Certain physiologic and pathologic states may alter MAC of inhaled anesthetics.
MAC is higher in infants and lower in the elderly. Also, MAC increases with
hyperthermia, alcoholism, and thyrotoxicosis. Furthermore, hypothermia, hypotension,
and pregnancy seem to decrease MAC, while duration of anesthesia, gender, height,
and weight seem to have little effect on MAC. Those with chronic liver disease are
also at increased risk of arterial–venous shunting.
20. B. Those with chronic liver disease are at increased risk of arterial–venous
shunting. The presence of intrapulmonary shunting will result in hypoxemia.
21. C. Cirrhosis is typically associated with several cardiovascular abnormalities
including a hyperdynamic circulation characterized by increased cardiac output and
decreased peripheral resistance. Other cardiovascular changes include a resting
tachycardia, warm peripheries, a bounding pulse, and a widened pulse pressure.
22. D. Obesity hypoventilation syndrome (aka Pickwickian syndrome) is a state in
which the severely overweight patient fails to breathe rapidly or deeply enough,
resulting in hypoxia and hypercarbia. If Pickwickian syndrome is suspected, the most
important initial test is the demonstration of elevated carbon dioxide in the blood.
This requires either an ABG or a measurement of bicarbonate levels in venous
blood. Expected ABG findings would reveal a chronic, compensated respiratory
23. B. Redistribution of thiopental to inactive tissue sites rather than metabolism is the
most important determinant of early awakening following a single intravenous
24. B. The Child-Turcotte-Pugh score is used to predict mortality during surgery in
surgery in patients who had undergone a transjugular intrahepatic portosystemic shunt
procedure and was subsequently found to be useful in determining prognosis and
prioritizing patients for liver transplant. Alvarado score is used for appendicitis,
while the Ranson criteria assess pancreatitis.
25. D. The MELD score is a formulaic calculation utilizing three variables: creatinine,
INR, and bilirubin. For dialysis-dependent patients, the creatinine score is
automatically set to 4 mg/dL despite true serum levels.
MELD score = 10 × [0.957 × log e (creatinine) + log e (bilirubin)
26. D. Standard technique of OLT causes changes in hemodynamics during the
anhepatic phase because of cross-clamping of the suprahepatic IVC. Interruption of
the IVC and portal vein flow causes a decrease in preload, cardiac output, and
arterial blood pressure. VVB has been used to achieve hemodynamic stability by
avoiding venous congestion, promoting venous return with decrease incidence of
27. B. Postreperfusion syndrome is the most common hemodynamic derangement in
liver transplantation, manifesting mainly as decreased heart rate, mean arterial
pressure, and systemic vascular resistances. Ventricular function, both right and left,
has been shown to be normal during reperfusion, in which case the visceral and liver
vasodilation that occurs would be the main cause of arterial hypotension. Prophylaxis
with atropine prevents bradycardia but not hypotension. Administration of calcium
chloride and sodium bicarbonate together with hyperventilation mitigates the
symptoms related to the reduced cardiac output.
28. A. Coagulopathy following massive transfusion is a consequence of posttraumatic
and surgical hemorrhage. Bleeding following massive transfusion can occur due to
hypothermia, dilutional coagulopathy, platelet dysfunction, fibrinolysis, or
hypofibrinogenemia. Transfusion of 15 to 20 U of blood products causes dilutional
thrombocytopenia contributing to the bleeding. Excessive fibrinolysis and low
fibrinogen are further causes of bleeding in these patients. The hemostatic signatures
of DIC are low platelets, low fibrinogen, prolonged prothrombin, prolonged PTT,
elevated D-dimers, and low antithrombin.
29. A. Long-standing insufficient liver function is believed to cause changes in the
circulation that changes vessel tone and blood flow in the kidneys. The likely
presence of renal insufficiency is a consequence of these changes in blood flow,
rather than direct damage to the kidney itself.
30. C. Dyspnea is a common complaint in individuals with class II or III obesity,
especially following a general anesthetic. As such, individuals present with a
pronounced reduction in expiratory reserve volume and an increase in the alveolar–
31. C. μ-Receptor agonism may contribute to sphincter of Oddi spasm, preventing
a μ-antagonist would alleviate any opioid-induced spasm.
32. C. A variety of agents that can produce smooth-muscle relaxation have been used.
Nitrates and calcium channel blockers have been the most extensively studied.
Anticholinergics, including atropine and glucagon, are additional agents that can
provide sphincter of Oddi relaxation. Metoclopramide is a promotility agent that
enhances sphincter smooth-muscle contraction.
33. B. Sympathetic celiac plexus blockade leaves parasympathetic fibers unopposed
with associated increased gastrointestinal motility and possible diarrhea.
34. C. Abdominal laparoscopy requires insufflation of the abdominal cavity, most
, to create a pneumoperitoneum. Increase in intra-abdominal
pressures will place the patient at a greater risk of reflux and aspiration; thus, general
anesthesia with an endotracheal tube is required. High pressures in the abdominal
cavity can also compress both small and large blood vessels, hampering venous
return to the heart. Intrathoracic pressures are also increased, associated with
diaphragm elevation, compromising cardiac output further. Increase in SVR occurs
during pneumoperitoneum, reflected as an increase in afterload for left-sided heart
35. C. Abdominal laparoscopy, though relatively safe, is associated with a few
inherent dangers including gaseous embolism, potential inability to control bleeding,
an increase in CO2 partial pressures and changes in arterial blood pressure and heart
rate. CO2 absorption from the peritoneal cavity can result in a state of acidosis as
36. A. The supine position under general anesthesia results in a decrease in functional
residual capacity (FRC). Pneumoperitoneum and the Trendelenburg position shifts
the diaphragm cephalad, further decreasing FRC. If FRC becomes less than closing
capacity, airway collapse, atelectasis, and ventilation/perfusion mismatch can further
compromise respiratory function. The judicious use of PEEP can be helpful to
mitigate end-expiratory alveolar collapse; however, too much PEEP can contribute to
deterioration in right-sided cardiac performance.
37. D. Systemic absorption of gas from pneumoperitoneum is determined by factors
including solubility of the gas, IAP, and duration of surgery. Therefore, CO2
laparoscopy may produce hypercarbia, particularly during long surgeries under high
IAP unless minute ventilation is increased. In those with severely compromised
cardiopulmonary function and restricted CO2 clearance, severe hypercarbia can
occur despite aggressive hyperventilation.
38. B. Hypercarbia causes hemodynamic changes by its direct action on the
cardiovascular system and indirect actions through the sympathetic nervous system.
Manifestations while under general anesthesia include tachycardia, arrhythmias, high
cardiac output, increased arterial blood pressure, and low SVR with flushed skin.
39. C. The effects of pneumoperitoneum include compression of the inferior vena cava
resulting in poor venous return and low preload. Systemic vascular resistance
increases proportionately when the intra-abdominal pressure is elevated, providing a
larger afterload against which the left ventricle must function. During insufflation, a
gas embolus can occur, entering the venous system to create an “air lock” with
mechanical obstruction of the right-side chambers. A blood pressure cuff that is too
small for the arm will result in erroneously high blood pressure readings.
40. D. The saphenous nerve is the largest and longest branch of the femoral nerve that
supplies sensory innervation to the medial aspect of the lower leg. Movement of the
41. D. High thoracic epidural blockade up to T2 blocks the cardiac accelerators,
providing adequate sympathectomy to prevent hypertension and tachycardia.
Sympathetic outflow to the pupil travels via the intermediolateral cell column at the
C8 to T2 cord level and remains intact; thus, the sympathetic surge can still result in
42. A. Transplant recipients are always under various regimens of immunosuppression
to prevent organ rejection. Clinically significant reductions in serum levels of these
medications can be caused by dilution with massive fluid resuscitation
perioperatively, as well as with cardiopulmonary bypass. Many immunosuppressants
are metabolized in the liver via the cytochrome P450 system such that drugs
administered during anesthesia (or perioperatively) may affect blood levels including
increased concentrations with cimetidine and metoclopramide and decreased levels
with octreotide. Regional anesthesia and/or TIVA are reasonable options to minimize
43. C. Normally, about 20 mL/min of irrigation fluid is absorbed (1–1.5 L for a normal
case with resection time about 45–60 minutes), which increases as the duration of the
surgery increases. In clinical practice, it is almost impossible to accurately assess the
volume absorbed. The amount of fluid absorbed depends on several other factors as
well, including the hydrostatic pressure of the irrigation infusion (determined by the
height of the bag), venous pressure (more fluid absorbed if patient is hypotensive),
the size of the prostate to be resected (associated with longer time required), blood
loss (implies a large number of open veins), and surgical skills of the surgeon
(efficiency with time management and hemostasis).
44. C. Another relatively common complication of TURP is perforation of the bladder.
Perforations usually occur during difficult resections and are often made by the
cutting loop or knife electrode. The tip of the resectoscope can also cause injury, as
well as overdistention of the bladder with irrigation fluid. Most perforations are
extraperitoneal, and in the awake patient, they result in pain in the periumbilical,
inguinal, or suprapubic regions; additionally, the urologist may note the irregular
return of irrigating fluid. Less often, the perforation is through the wall of the bladder
and thus intraperitoneal. In such cases, pain may be generalized, in the upper
abdomen, or referred from the diaphragm to the shoulder. Bacteremia is usually
asymptomatic and easily treated with commonly used antibiotic combinations that
are effective against gram-positive and gram-negative bacteria.
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