antagonism (e.g., prochlorperazine) are useful antiemetics, with no effect on gastric

pH or volume.

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%

of normal to prolong the ACT.

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

injury.

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

after anesthesia.

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

acidosis.

23. B. Redistribution of thiopental to inactive tissue sites rather than metabolism is the

most important determinant of early awakening following a single intravenous

injection.

24. B. The Child-Turcotte-Pugh score is used to predict mortality during surgery in

patients with chronic liver disease, namely, cirrhosis. The Mayo or model for endstage liver disease was initially developed to predict death within 3 months of

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)

+ 1.12 × log e (INR)] + 6.43

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

renal dysfunction.

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–

arterial oxygen gradient.

31. C. μ-Receptor agonism may contribute to sphincter of Oddi spasm, preventing

passage of contrast with full μ-agonist more likely to contribute versus partial μagonists (e.g., buprenorphine) and agonist–antagonist (e.g., nalbuphine). Naloxone, as

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

commonly using CO2

, 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

chambers.

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

PaCO2

rises.

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

foot is unaffected.

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

mydriasis.

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

PONV in this patient.

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.