36. C. As per ASA guidelines, it is recommended to wait at least 6 hours after
ingestion of nonhuman milk before performing an elective operation in a child.
37. C. Volatile inhalation agents and succinylcholine are considered triggers for
malignant hyperthermia (MH) reaction. MH has a genetic component, and runs in
families. Since her aunt had a severe reaction to anesthesia, further details should be
obtained from the history. If any doubt about the history, the patient should be
assumed to be prone to developing MH. Volatile agents and succinylcholine should
38. B. Elective surgery should be postponed for at least 6 weeks after a myocardial
infarction. Risk of reinfarction is approximately 5.5% for surgeries between 0 and 3
months, 2.5% between 3 and 6 months, and 2% after 6 months of a myocardial
39. A. The most significant risk factor for developing pulmonary complications is the
upper abdominal or thoracic site of surgery. As such, all patients undergoing such
surgeries should be optimally prepared for the surgery. This includes pulmonary
toilet: chest physiotherapy/exercises, and postural drainage of mucus and secretions.
40. C. There is no specific value of INR before a patient is taken to the OR for
elective surgery. However, it is recommended that an INR value of 1.4 or less should
be aimed for before taking the patient to the OR for elective surgery. In case of
emergency, the INR can be normalized by infusing fresh-frozen plasma.
41. C. The paralyzed muscles due to central denervation eventually develop atrophy.
Extrajunctional receptors are then synthesized at the muscle sites, which remain
resistant to the effects of neuromuscular blockade for varying degrees. Thus, these
paralyzed muscles give an exaggerated response on direct stimulation with a nerve
stimulator. Therefore, muscle twitch monitoring should be done on the nonaffected
sites to correctly monitor the degree of neuromuscular blockade.
42. B. MAC typically is found to be lower for patients on sedatives, anxiolytics,
alcohol intoxication, hypothermia, extremes of age, moribund/sick patients, and
patients with obtunded consciousness. Chronic alcohol abuse, however, increases
43. A. All β2 agonists are known to cause internalization of potassium (from plasma to
cell), thus causing hypokalemia. This principle is sometimes used in the treatment of
44. D. Smoking cessation for 24 hours before surgery reduces carboxyhemoglobin
(COHb) levels. Reduced levels of COHb increases levels of oxygenated Hb, which
decreases the risk of myocardial ischemia and perioperative cardiac morbidity.
Delayed benefits (cessation more than 8 weeks) are known to improve airway
immunologic and ciliary function.
45. D. Among all these tests, TEG has the highest positive predictive value for
diagnosing a bleeding tendency. Deranged values from other tests listed have not
shown to always correlate well with bleeding tendency. For example, the other tests
will be deranged in a patient with sepsis but may not show a clinically relevant
46. D. All the other choices need evaluation/optimization prior to elective noncardiac
surgery. Uncontrolled systolic hypertension without target end-organ damage is a
minor predictor/risk factor. It can be usually controlled with intraoperative
antihypertensive medications without evidence of significant adverse outcomes.
47. C. Glycopyrrolate is a synthetic quaternary amine with antimuscarinic properties
and no central side effects like sedation. All the other choices are as a result of
direct consequence of cholinergic blockade.
48. C. Metoclopramide is a prokinetic agent that enhances gastric clearance and
increases lower esophageal sphincter tone, preventing vomiting, but may not actually
work for nausea (vomiting rather than nausea is prevented). It blocks the
dopaminergic receptors to cause parkinsonism-like extrapyramidal side effects.
49. B. Preoxygenation of lungs primarily acts to increase safe apnea time by
denitrogenating functional residual capacity (FRC) and increasing dissolved oxygen
content in the blood. It does not alter any physical measurements of lungs; that is, it
has no effect on FRC or on closing volume/capacity.
50. A. Halothane, especially on repeated administration, can cause two subtypes of
hepatitis (type 1 is immunogenic—mild—and type 2 is due to direct effect of
halothane on liver cells). The incidence of halothane hepatitis is around 1 in 10,000
to 1 in 35,000 halothane anesthetics.
51. C. Both halothane and sevoflurane have been used for inhalation induction in the
pediatric population. Sevoflurane has largely replaced halothane due to a better
safety profile, and has emerged as the induction agent of choice in pediatric
52. D. Nitrous oxide is known to inhibit the enzyme “methionine synthase,” inhibiting
DNA synthesis and precipitating B12 deficiency, causing pernicious megaloblastic
anemia. Nitrous oxide is also known to act on NMDA receptors and also increase
pulmonary vascular resistance.
53. D. All the mechanisms have been proposed for propofol in preventing nausea and
vomiting in the postoperative period (PONV). Propofol, when used, is used in
refractory cases of PONV and in low doses.
54. C. Ketamine preserves spontaneous respiration and airway tone without causing
apnea at induction doses. Propofol and benzodiazepines are associated with
respiratory depression at induction doses and cause apnea.
55. B. Succinylcholine should not be used in patients with a history of muscular
dystrophy or patients with a history of malignant hyperthermia. Myasthenia gravis
patients may show resistance to Phase I block of succinylcholine. In patients with full
stomach, succinylcholine is used in “rapid sequence intubation” to prevent
56. B. Multiple studies have shown propensity of ACE inhibitors to precipitate
profound hypotension at induction of general anesthesia, especially in the geriatric
age group. Hence, ACE inhibitors should be with held on the day of the surgery,
especially in the elderly and for major surgeries.
57. D. Morbidly obese patients with OSA are often subject to persistent hypoxia,
which leads to increased pulmonary vascular resistance, eventually leading to
pulmonary artery hypertension. Obese patients are also known to have a higher
incidence of cardiac problems, including a dilated heart and heart failure.
Compression neuropathies are also common in this subpopulation. Dementia is a
central-nervous-system–related complication not associated directly with obesity.
58. D. Remifentanil preparations available in the market have glycine as the
preservative, which can cause direct neurotoxicity. Thus, it is recommended that
remifentanil preparations be not used for central neuraxial blockade.
59. D. Ondansetron exerts its antiemetic effect by acting as an antagonist on the 5-HT3
receptors. Drugs in the same category include palonosetron and granisetron. Rarely
reported side effects of these agents include QT prolongation, hypotension, and
60. C. Scopolamine is an antimuscarinic drug that can cross the blood–brain barrier
and cause sedation and confusion, especially in the elderly. It does not produce
61. D. Dexmedetomidine is an α2
receptor agonist, with about eight times greater
affinity for the receptor than clonidine. Continuous infusion is more likely to result in
62. C. Addisonian crisis or acute adrenal insufficiency during the perioperative period
occurs in patients with known adrenal insufficiency or in those receiving chronic
steroid therapy. The latter causes hypothalamic–pituitary axis suppression. Patients
with adrenal insufficiency may present with refractory shock with electrolyte and
glucose abnormalities. Treatment consists of administration of hydrocortisone and
correction of associated derangements.
63. B. Promethazine is commonly used as an antiemetic. It has antidopaminergic
activity, and in addition also has antihistaminic and anti–α-adrenergic activity.
64. A. Factors that are associated with an increased risk of postoperative nausea and
vomiting include previous history of postoperative nausea and vomiting, female
gender, obesity, nonsmoking, pain, eye or ear surgery, laparoscopic surgery,
anesthetic drugs, and gastric distention.
65. A. Abrupt withdrawal of TPN will most commonly result in hypoglycemia due to
the high circulating insulin levels.
66. A. Glycopyrrolate is an anticholinergic drug with a quaternary ammonium
structure, which prevents it from crossing the blood–brain barrier. Therefore, it has
no central nervous system effects (sedation). Glycopyrrolate increases the heart rate,
causes dryness of secretions, and lowers the lower esophageal sphincter tone. The
latter may predispose a patient to pulmonary aspiration of gastric contents.
67. B. Patients taking herbal medications for their alleged benefits are often unaware of
their potential side effects (bleeding tendency, platelet dysfunction, etc.). Most
medications must be stopped for at least 7 days prior to surgery.
68. A. Gentamicin is an aminoglycoside antibiotic that blocks acetylcholine release
from the presynaptic terminals and reduces postsynaptic responsiveness. This may
prolong neuromuscular blockade associated with nondepolarizing muscle relaxants.
69. B. Estrogen intake can lead to a hypercoagulable state, predisposing women to
thromboembolic events. Other risk factors for thromboembolism include major
surgery, multiple trauma (hip fracture), lower extremity paralysis, increasing age,
cardiac or respiratory failure, prolonged immobility, presence of central venous lines,
and a wide variety of hematologic conditions (inherited or acquired).
70. C. Because of its narrow therapeutic index, lithium dosing requires constant
surveillance with monitoring of levels and dosage adjustment. Three types of lithium
intoxication can occur—acute, acute or chronic, and chronic. Chronic lithium
intoxication occurs in those patients on long-term lithium therapy.
• Mild toxicity: manifests as lethargy, drowsiness, coarse hand tremor, muscle
weakness, nausea, vomiting, and diarrhea
• Moderate toxicity: manifests as confusion, dysarthria, nystagmus, ataxia,
myoclonic twitches, and flat or inverted T-waves on ECG
• Severe toxicity: may be life-threatening. It may present with grossly impaired
consciousness, increased deep tendon reflexes, seizures, syncope, renal
insufficiency, coma, and death.
71. A. Patients under treatment with MAOIs have an increased availability of
endogenous norepinephrine. Therefore, treatment with an indirect-acting drug such as
ephedrine can lead to an exaggerated response. Hypotension in these patients is
better managed with a direct-acting drug such as phenylephrine.
72. B. Patients taking oral hypoglycemic agents may experience delayed hypoglycemia
in the absence of caloric intake in the intraoperative and postoperative periods.
Hence, patients should be advised not to take oral hypoglycemic agents the morning
of the surgery. In addition, metformin should be stopped at least 48 hours before
surgery as it may precipitate the development of lactic acidosis during surgery.
Patients on an insulin pump should continue the insulin at the basal rate.
73. B. Digoxin is an inotrope that blocks the Na
+ ATPase pump on the myocardial
cell. It causes calcium ions to enter the cells, but causes a net K
Thus, hypokalemia, more so than hypercalcemia, will exacerbate digitalis toxicity.
Signs and symptoms of digoxin toxicity include drowsiness or confusion,
nausea/vomiting, loss of appetite, diarrhea, disturbed color vision (yellow or green
halos around objects), agitation, and cardiac dysrhythmias. Characteristic EKG
changes include bradycardia, a prolonged PR interval, or an accelerated junctional
74. C. During central line insertion, the guide wire or the tip of the catheter enters the
right atrium and may result in an arrhythmia, which returns to sinus rhythm when the
guide wire/catheter tip is withdrawn out of the heart.
75. C. Antibiotic allergies may result in an anaphylactic or anaphylactoid reaction.
Based on the patient’s presentation, anaphylactic shock is the most consistent
diagnosis and needs to be treated with epinephrine first, which reverses most of the
manifestations of anaphylaxis.
76. D. The ulnar nerve is frequently spared with an interscalene block. Complications
of an interscalene block include stellate ganglion block, phrenic nerve block,
recurrent laryngeal nerve block, Horner syndrome, vertebral artery injection,
epidural/subarachnoid/subdural injection, and pneumothorax.
77. A. An axillary nerve block produces blockade of the median, ulnar, and the radial
nerves. Sensation to the lateral aspect of the forearm is provided by the
musculocutaneous nerve, which must be blocked separately (deep injection into the
78. D. The femoral nerve lies lateral to the femoral artery, which is lateral to the
femoral vein (VAN—vein, artery, nerve; medial to lateral).
79. D. The ankle block blocks the deep peroneal nerve, the saphenous nerve, the
posterior tibial nerve, the sural nerve, and the superficial peroneal nerve.
80. A. Laryngopharyngitis is more common after an endotracheal intubation than when
using a laryngeal mask airway. The incidence of sore throat can vary from 15% to
40%, and depends on operator experience (less trauma). Use of smaller endotracheal
tubes, smaller cuff sizes (less area of contact with tracheal mucosa), and low
pressure in the tracheal cuff decrease the incidence of postoperative sore throat.
Using lidocaine jelly to lubricate the endotracheal tube (rather than lubricating jelly)
increases the incidence of sore throat. Most cases of sore throat resolve
81. B. In HOCM, obstruction of the ventricular outflow tract can occur from systolic
anterior motion of the mitral valve against the hypertrophied septum. In patients with
a severe HOCM, myocardial depression is beneficial, which can be obtained by
using β-blockers (metoprolol) or calcium channel blockers.
82. D. St. John wort is a commonly used herbal medication that is a CYP2C19- and
CYP3A4 inducer. As clopidogrel is activated by the cytochrome P450 system, St.
John wort may be used to increase the effect of clopidogrel in hyporesponders. It
reduces the effect of warfarin and heparin, with little effect on aspirin.
83. C. Advanced age is the most important predictor of atrial fibrillation not only in
patients following cardiac surgery but also in the general population.
84. C. Parkinson disease is characterized by a loss of dopamine in the nigrostriatum,
resulting in bradykinesia, rigidity, postural instability, and pill-rolling resting tremor.
Metoclopramide (and droperidol) has significant antidopaminergic properties and
should be avoided in these patients in the treatment of nausea and vomiting.
85. B. The New York Heart Association classification for heart failure is based on
both a functional and objective assessment of the patient’s capabilities and
symptoms. This patient is asymptomatic at rest and can go about his activities of
daily living without issues. However, with more strenuous activity, he becomes
dyspneic. His classification would, therefore, be 2 (Tables 1-1 and 1-2).
Table 1-1 Functional capacity: How a patient with cardiac disease feels during physical activity
Class I: Patients with cardiac disease but resulting in no limitation of
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