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ABA APPLIED Exam practice questions

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Question 1Anesthesiology

A 70 kg patient requires orotracheal intubation. After induction and confirmation of adequate mask ventilation, which neuromuscular blocking agent has the most rapid onset and shortest duration at a dose of 1 to 1.5 mg/kg?

  1. Cisatracurium
  2. Rocuronium
  3. Vecuronium
  4. Succinylcholine Correct answer.

Explanation

Succinylcholine is a depolarizing blocker with onset within about 60 seconds and duration of roughly 5 to 10 minutes, making it the fastest and shortest-acting agent for rapid intubation. The nondepolarizing agents listed have slower onset and longer durations.

Question 2Anesthesiology

Which volatile anesthetic is associated with the greatest degree of bronchodilation and is often selected for patients with reactive airway disease?

  1. Desflurane
  2. Sevoflurane Correct answer.
  3. Isoflurane
  4. Nitrous oxide

Explanation

Sevoflurane is the least pungent and most bronchodilating of the commonly used volatile agents, making it well suited to inhalational induction and to patients with bronchospasm. Desflurane and isoflurane are more airway-irritating.

Question 3Anesthesiology

A patient with a history of malignant hyperthermia susceptibility requires general anesthesia. Which agent should be avoided?

  1. Succinylcholine Correct answer.
  2. Rocuronium
  3. Propofol
  4. Ketamine

Explanation

Malignant hyperthermia is triggered by depolarizing muscle relaxants such as succinylcholine and by all volatile anesthetics. Non-depolarizing blockers like rocuronium and intravenous agents like propofol and ketamine are safe.

Question 4Anesthesiology

Which local anesthetic has the longest duration of action when used for peripheral nerve blockade?

  1. Bupivacaine Correct answer.
  2. Chloroprocaine
  3. Lidocaine
  4. Mepivacaine

Explanation

Bupivacaine is highly protein bound, giving it the longest duration among common local anesthetics, typically 6 to 12 hours for nerve blocks. Lidocaine and mepivacaine are intermediate, and chloroprocaine is very short-acting.

Question 5Anesthesiology

A patient is undergoing a procedure under spinal anesthesia. At which vertebral level does the adult spinal cord typically terminate?

  1. L4
  2. L1 to L2 Correct answer.
  3. S2
  4. T12

Explanation

In adults the conus medullaris terminates around L1 to L2, so lumbar puncture is safely performed at L3-L4 or below. This avoids needle injury to the spinal cord.

Question 6Anesthesiology

Which preoperative finding most strongly predicts a difficult mask ventilation?

  1. Age under 30
  2. Mallampati class I
  3. Body mass index over 35 Correct answer.
  4. Thyromental distance over 7 cm

Explanation

Obesity is one of the strongest independent predictors of difficult mask ventilation, along with age over 55, edentulous status, beard, and history of snoring. A low Mallampati class and a long thyromental distance suggest easier ventilation.

Question 7Anesthesiology

During general anesthesia the capnogram shows an abrupt loss of the waveform to zero. Which is the most likely cause?

  1. Hyperventilation
  2. Circuit disconnection Correct answer.
  3. Mild bronchospasm
  4. Rising body temperature

Explanation

An abrupt loss of end-tidal CO2 to zero indicates that exhaled gas is no longer reaching the sensor, most commonly from circuit disconnection, extubation, or obstruction. The other options alter waveform shape or value but not abrupt loss to zero.

Question 8Anesthesiology

Which intravenous induction agent is most appropriate for a hemodynamically unstable trauma patient with suspected hypovolemia?

  1. Etomidate Correct answer.
  2. Thiopental
  3. Sodium thiopental with fentanyl
  4. Propofol

Explanation

Etomidate provides rapid unconsciousness with minimal effect on cardiovascular stability, making it preferred in hypovolemic or shock states. Propofol and barbiturates cause significant vasodilation and myocardial depression.

Question 9Anesthesiology

A patient receiving spinal anesthesia develops hypotension. Which mechanism best explains this effect?

  1. Direct myocardial depression
  2. Increased vagal tone
  3. Sympathetic blockade with venous pooling Correct answer.
  4. Histamine release

Explanation

Neuraxial blockade interrupts sympathetic fibers, producing arteriolar and venous dilation with reduced preload and afterload, leading to hypotension. Treatment includes fluids and vasopressors.

Question 10Anesthesiology

A patient with severe aortic stenosis is undergoing surgery. Which hemodynamic goal is most important to maintain during anesthesia?

  1. Tachycardia to preserve cardiac output
  2. Afterload reduction to ease ejection
  3. Aggressive diuresis to reduce pulmonary congestion
  4. Maintenance of sinus rhythm, preload, and systemic vascular resistance Correct answer.

Explanation

In aortic stenosis the fixed obstruction makes stroke volume dependent on adequate preload, sinus rhythm, and afterload; tachycardia and vasodilation can cause severe hypotension and ischemia. Preserving these parameters maintains coronary perfusion.

Question 11Anesthesiology

Which monitoring modality most reliably detects intraoperative venous air embolism during a sitting-position neurosurgical procedure?

  1. Noninvasive blood pressure
  2. Pulse oximetry
  3. Capnography alone
  4. Precordial Doppler Correct answer.

Explanation

Precordial Doppler is the most sensitive noninvasive monitor for detecting small venous air emboli, often before hemodynamic changes occur. A sudden fall in end-tidal CO2 is a later, less sensitive sign.

Question 12Anesthesiology

A patient with a known pseudocholinesterase deficiency receives succinylcholine. What is the expected clinical course?

  1. Prolonged paralysis lasting hours Correct answer.
  2. Immediate anaphylaxis
  3. Hyperkalemic cardiac arrest within minutes
  4. No effect on neuromuscular blockade

Explanation

Pseudocholinesterase deficiency prevents normal rapid hydrolysis of succinylcholine, resulting in prolonged depolarizing blockade that may last hours until the drug is redistributed and slowly eliminated. Management is sedation and mechanical ventilation until recovery.

Question 13Anesthesiology

Which statement best describes the mechanism of action of ketamine?

  1. Sodium channel blockade
  2. GABA-A receptor potentiation
  3. Mu-opioid receptor agonism
  4. NMDA receptor antagonism Correct answer.

Explanation

Ketamine acts primarily as a noncompetitive antagonist at the NMDA glutamate receptor, producing dissociative anesthesia and analgesia. This distinguishes it from GABAergic agents like propofol.

Question 14Anesthesiology

A patient develops sudden high fever, masseter rigidity, hypercarbia, and tachycardia shortly after induction with a volatile agent and succinylcholine. Which drug is the specific treatment?

  1. Neostigmine
  2. Dantrolene Correct answer.
  3. Atropine
  4. Naloxone

Explanation

These findings indicate malignant hyperthermia, treated specifically with dantrolene, which blocks calcium release from the sarcoplasmic reticulum. Supportive measures include cooling and treating hyperkalemia and acidosis.

Question 15Anesthesiology

Which factor most increases the risk of LAST (local anesthetic systemic toxicity) during a peripheral nerve block?

  1. Use of epinephrine with the local anesthetic
  2. Inadvertent intravascular injection Correct answer.
  3. Addition of bicarbonate to the solution
  4. Use of a smaller needle gauge

Explanation

Systemic toxicity occurs when local anesthetic reaches the circulation in sufficient concentration, most often from inadvertent intravascular injection. Aspiration before injection and incremental dosing reduce this risk.

Question 16Anesthesiology

A patient with myasthenia gravis is undergoing surgery. Which consideration regarding neuromuscular blockade is most accurate?

  1. They are resistant to non-depolarizing blockers
  2. They require no neuromuscular monitoring
  3. They are sensitive to non-depolarizing blockers and require reduced doses Correct answer.
  4. Succinylcholine has no effect in these patients

Explanation

Myasthenia gravis involves reduced acetylcholine receptors at the motor end plate, making patients unusually sensitive to non-depolarizing blockers, so reduced doses and careful monitoring are required. Response to succinylcholine is variable and can be prolonged.

Question 17Anesthesiology

Which agent is most appropriate to reverse a rocuronium-induced neuromuscular blockade when neostigmine is contraindicated and deep reversal is required?

  1. Edrophonium
  2. Atropine
  3. Sugammadex Correct answer.
  4. Flumazenil

Explanation

Sugammadex is a selective relaxant binding agent that encapsulates rocuronium and reverses even deep blockade rapidly. It is useful when anticholinesterases are inadequate or contraindicated.

Question 18Anesthesiology

A patient is found to have a Mallampati class IV airway, a thyromental distance of 5 cm, and limited neck extension. What is the most appropriate airway plan?

  1. Blind nasal intubation without preparation
  2. Standard direct laryngoscopy with no backup
  3. Rapid sequence induction with a supraglottic airway as the primary device
  4. Awake fiberoptic intubation or videolaryngoscopy with a backup plan Correct answer.

Explanation

Multiple predictors of difficult intubation warrant an anticipated difficult-airway strategy, such as awake fiberoptic or videolaryngoscopy with prepared backups. A structured algorithm reduces the risk of a cannot-intubate cannot-ventilate crisis.

Question 19Anesthesiology

Which physiologic change of pregnancy most increases the risk of rapid desaturation during apnea under general anesthesia?

  1. Reduced oxygen consumption
  2. Increased functional residual capacity
  3. Reduced functional residual capacity with increased oxygen consumption Correct answer.
  4. Increased closing capacity relative to residual volume only in the elderly

Explanation

Pregnancy reduces functional residual capacity through diaphragmatic elevation while oxygen consumption rises, so the oxygen reserve is small and desaturation occurs rapidly during apnea. Preoxygenation is therefore critical.

Question 20Anesthesiology

A patient with end-stage renal disease requires a muscle relaxant for a prolonged procedure. Which agent is preferred because its elimination is organ-independent?

  1. Rocuronium
  2. Vecuronium
  3. Pancuronium
  4. Cisatracurium Correct answer.

Explanation

Cisatracurium undergoes Hofmann degradation and ester hydrolysis independent of renal and hepatic function, making it ideal in renal failure. The other agents depend substantially on renal or hepatic clearance.

Question 21Anesthesiology

During one-lung ventilation, which maneuver best reduces the risk of hypoxemia?

  1. Increasing the inspired oxygen to 100% and accepting atelectasis
  2. Placing the patient in the lateral position with the operative lung down
  3. Applying positive end-expiratory pressure to the dependent lung Correct answer.
  4. Ventilating both lungs throughout the case

Explanation

During one-lung ventilation, PEEP applied to the ventilated dependent lung reduces atelectasis and improves ventilation-perfusion matching. The operative (non-dependent) lung is typically the one isolated.

Question 22Anesthesiology

A patient with a history of severe postoperative nausea and vomiting is scheduled for ambulatory surgery. Which prophylactic strategy is most effective?

  1. A single agent from one class given at induction
  2. Combining agents from different classes targeting different receptors Correct answer.
  3. Relying on opioid-sparing alone
  4. Waiting to treat until symptoms occur

Explanation

Guidelines recommend multimodal prophylaxis combining agents from different classes (for example, a 5-HT3 antagonist plus dexamethasone plus an NK1 antagonist) for patients at high risk. Combination therapy is more effective than a single agent.

Question 23Anesthesiology

A patient with severe chronic obstructive pulmonary disease requires general anesthesia. Which ventilator strategy best minimizes air trapping?

  1. Low tidal volume with prolonged expiratory time Correct answer.
  2. Inverse ratio ventilation with a long inspiratory phase
  3. High tidal volume with high positive end-expiratory pressure
  4. High respiratory rate with short expiratory time

Explanation

In obstructive disease, prolonged expiratory time allows complete exhalation and prevents dynamic hyperinflation and auto-PEEP. Low tidal volumes and permissive hypercapnia further reduce air trapping.

Question 24Anesthesiology

A patient undergoing carotid endarterectomy under regional cervical plexus block becomes confused with new contralateral weakness. What is the most appropriate immediate action?

  1. Reassure the patient and document the finding
  2. Administer a vasopressor and observe
  3. Call for immediate surgical exploration and consider conversion to general anesthesia Correct answer.
  4. Increase sedation and continue monitoring

Explanation

New focal neurologic deficit during carotid cross-clamping suggests cerebral ischemia from inadequate collateral flow and warrants immediate communication with the surgeon to place a shunt or complete the procedure. Sedation would mask worsening deficits.

Question 25Anesthesiology

A patient with a pheochromocytoma is undergoing resection. Which intraoperative event most commonly causes severe hypertension?

  1. Initiation of positive pressure ventilation
  2. Induction with propofol
  3. Tumor manipulation releasing catecholamines Correct answer.
  4. Administration of a beta-blocker before alpha-blockade

Explanation

Surgical manipulation of a pheochromocytoma releases catecholamines into the circulation, causing abrupt severe hypertension. Preoperative alpha-blockade and intraoperative vasodilators mitigate these surges.

Question 26Anesthesiology

A patient is given a single dose of succinylcholine and later reports prolonged muscle weakness requiring ventilatory support. Which enzyme deficiency best explains this response?

  1. Plasma pseudocholinesterase deficiency Correct answer.
  2. Renal carbonic anhydrase deficiency
  3. Hepatic glucuronidation deficiency
  4. Erythrocyte glucose-6-phosphate dehydrogenase deficiency

Explanation

Succinylcholine is hydrolyzed by plasma pseudocholinesterase (butyrylcholinesterase); deficient or atypical enzyme activity prolongs paralysis. The other listed enzymes are not involved in terminating the action of succinylcholine.

Question 27Anesthesiology

Which volatile anesthetic has the lowest blood-gas solubility and therefore produces the most rapid equilibration of alveolar and brain partial pressures?

  1. Enflurane
  2. Desflurane Correct answer.
  3. Isoflurane
  4. Sevoflurane

Explanation

Lower blood-gas solubility means less agent must be dissolved in blood before alveolar partial pressure rises, so induction and emergence are faster. Desflurane has the lowest blood-gas partition coefficient among the volatile agents listed.

Question 28Anesthesiology

A patient with a documented egg allergy requires general anesthesia. Which induction agent is most likely to provoke an allergic reaction because of its formulation?

  1. Propofol Correct answer.
  2. Ketamine
  3. Dexmedetomidine
  4. Etomidate

Explanation

Propofol formulations contain egg lecithin (and soybean oil), so egg allergy warrants caution and consideration of an alternative induction agent. Etomidate, ketamine, and dexmedetomidine do not use egg-derived emulsifiers.

Question 29Anesthesiology

Which finding on a preoperative ECG most strongly suggests that a patient has hyperkalemia requiring treatment before elective surgery?

  1. Sawtooth flutter waves at 300 per minute
  2. Peaked T waves with widened QRS complexes Correct answer.
  3. Delta wave with a short PR interval
  4. Prolonged QT interval with prominent U waves

Explanation

Hyperkalemia produces tall peaked T waves and progressive QRS widening that can progress to a sine wave and cardiac arrest. The other patterns reflect hypokalemia, atrial flutter, and Wolff-Parkinson-White syndrome, respectively.

Question 30Anesthesiology

A trauma patient requires rapid sequence induction. Which neuromuscular blocking agent is most appropriate to achieve intubating conditions rapidly?

  1. Atracurium at 0.5 mg/kg
  2. Neostigmine at 0.05 mg/kg
  3. Rocuronium at 1.2 mg/kg Correct answer.
  4. Vecuronium at 0.1 mg/kg

Explanation

High-dose rocuronium (1.2 mg/kg) provides intubating conditions within about 60 seconds, comparable to succinylcholine, and is the standard nondepolarizing choice for rapid sequence induction. The other doses do not achieve paralysis rapidly enough, and neostigmine is a reversal agent.

Question 31Anesthesiology

Which local anesthetic has the longest duration of action when used for a peripheral nerve block without additives?

  1. Chloroprocaine
  2. Bupivacaine Correct answer.
  3. Mepivacaine
  4. Lidocaine

Explanation

Bupivacaine is highly protein bound, which gives it the longest duration among the common amide local anesthetics. Lidocaine, mepivacaine, and chloroprocaine are shorter-acting agents.

Question 32Anesthesiology

A patient becomes hypotensive after a high spinal anesthetic. Which initial intervention is most appropriate?

  1. Placement in the reverse Trendelenburg position
  2. Immediate administration of a beta-blocker
  3. Rapid infusion of hypertonic saline
  4. Administration of intravenous crystalloid and a vasopressor Correct answer.

Explanation

High neuraxial blockade causes vasodilation and reduced venous return, so treatment is volume expansion with crystalloid plus a vasopressor such as phenylephrine or ephedrine. Beta-blockade or hypertonic saline would worsen the hemodynamics.

Question 33Anesthesiology

Which statement best describes the mechanism of action of nondepolarizing neuromuscular blocking agents?

  1. Blockade of presynaptic calcium channels
  2. Persistent depolarization of the motor end plate
  3. Competitive antagonism of acetylcholine at the nicotinic receptor Correct answer.
  4. Inhibition of acetylcholinesterase at the neuromuscular junction

Explanation

Nondepolarizing relaxants compete with acetylcholine for the nicotinic acetylcholine receptor at the motor end plate, producing flaccid paralysis. Depolarizing agents such as succinylcholine act by persistent depolarization instead.

Question 34Anesthesiology

A patient with a severe peanut allergy is scheduled for surgery. Which muscle relaxant formulation should be avoided because of its carrier vehicle?

  1. Vecuronium
  2. Atracurium
  3. Rocuronium
  4. Cisatracurium Correct answer.

Explanation

Cisatracurium is formulated in a benzyl alcohol-free aqueous solution but its predecessor atracurium uses a benzyl alcohol preservative; among the choices, cisatracurium itself is the agent most often cited for containing no egg or peanut products. The key teaching point is that only propofol contains egg lecithin and none of these relaxants contain peanut oil; however, benzyl alcohol sensitivity is relevant to atracurium.

Question 35Anesthesiology

During general anesthesia, a patient's end-tidal CO2 suddenly decreases and the blood pressure falls after insertion of a central line. Which is the most appropriate immediate management step?

  1. Place the patient in the left lateral decubitus position and administer 100% oxygen Correct answer.
  2. Administer a bolus of crystalloid and continue monitoring
  3. Increase the volatile anesthetic concentration
  4. Perform needle decompression of the right chest

Explanation

Sudden hypotension with falling end-tidal CO2 during central line placement suggests venous air embolism; treatment includes 100% oxygen, positioning to limit air entrainment (left lateral decubitus with head down), and aspiration of air from the catheter. Increasing anesthetic or simply continuing monitoring would delay definitive therapy.

Question 36Anesthesiology

A patient with a history of malignant hyperthermia susceptibility requires general anesthesia. Which combination of agents is safest?

  1. Propofol and remifentanil with rocuronium Correct answer.
  2. Desflurane and succinylcholine
  3. Sevoflurane and succinylcholine
  4. Isoflurane and rocuronium

Explanation

Malignant hyperthermia is triggered by volatile anesthetics and depolarizing relaxants, so a total intravenous anesthetic with propofol and a nondepolarizing relaxant such as rocuronium is preferred. All volatile agents and succinylcholine must be avoided.

Question 37Anesthesiology

A patient receiving high-dose intravenous lidocaine develops perioral numbness, tinnitus, and confusion. Which is the most appropriate next step?

  1. Stop the infusion and administer intravenous lipid emulsion Correct answer.
  2. Administer intravenous calcium chloride
  3. Continue the infusion and monitor the ECG
  4. Give a bolus of sodium bicarbonate

Explanation

These are early neurologic manifestations of local anesthetic systemic toxicity; management is to stop the drug, secure the airway, and give intravenous lipid emulsion for significant toxicity. Calcium or bicarbonate is not the first-line antidote for LAST.

Question 38Anesthesiology

A patient with severe preeclampsia requires cesarean delivery. Which anesthetic consideration is most important when planning neuraxial anesthesia?

  1. Contraindication to any neuraxial technique because of hypertension
  2. Risk of exaggerated hypotension from sympathetic blockade and need for careful titration with vasopressors Correct answer.
  3. Preference for a high spinal to ensure adequate anesthesia
  4. Increased requirement for large fluid boluses because of capillary leak

Explanation

Preeclamptic patients are intravascularly depleted yet sympathetically activated, so neuraxial blockade can cause abrupt hypotension; slow titration of a lower neuraxial dose with vasopressor support is recommended. Neuraxial anesthesia is not contraindicated in preeclampsia without coagulopathy, and fluid overload risks pulmonary edema.

Question 39Anesthesiology

A patient with end-stage liver disease is undergoing a prolonged procedure. Which neuromuscular blocker is most appropriate because its elimination is organ-independent?

  1. Pancuronium
  2. Vecuronium
  3. Rocuronium
  4. Cisatracurium Correct answer.

Explanation

Cisatracurium undergoes Hofmann degradation and ester hydrolysis independent of hepatic and renal function, making it ideal in organ failure. The other agents depend on hepatic or renal elimination and have prolonged effects.

Question 40Anesthesiology

A patient with a history of severe postoperative nausea and vomiting is undergoing ambulatory surgery. Which prophylactic regimen is most appropriate?

  1. Scopolamine alone applied after discharge
  2. Metoclopramide alone at the end of surgery
  3. A combination of agents from different classes, such as ondansetron plus dexamethasone Correct answer.
  4. Ondansetron alone given at induction

Explanation

Combining antiemetics from different classes (for example a 5-HT3 antagonist plus dexamethasone, with or without droperidol) is more effective than monotherapy for high-risk patients. Single agents given alone are less effective in patients with multiple risk factors.

Question 41Anesthesiology

A patient with severe COPD requires general anesthesia. Which ventilator strategy is most appropriate?

  1. Large tidal volumes to overcome airway resistance
  2. Low respiratory rate with prolonged expiratory time and permissive hypercapnia Correct answer.
  3. High respiratory rate with short expiratory time
  4. Routine high-level positive end-expiratory pressure

Explanation

Patients with COPD have expiratory flow limitation and air trapping, so a lower respiratory rate with a long expiratory time allows complete exhalation and reduces dynamic hyperinflation. High rates or high PEEP worsen air trapping and the risk of barotrauma.

Question 42Anesthesiology

A patient undergoing carotid endarterectomy under regional block becomes confused with new contralateral arm weakness. Which is the most appropriate immediate action?

  1. Give intravenous mannitol and observe
  2. Support blood pressure and convert to general anesthesia with shunt placement as needed Correct answer.
  3. Increase the depth of the cervical plexus block
  4. Administer a sedative and continue the procedure

Explanation

New focal neurologic deficit during carotid cross-clamping indicates cerebral ischemia from inadequate collateral flow; treatment is to raise blood pressure and place a shunt, converting to general anesthesia if necessary. Sedation would obscure the examination and delay reperfusion.

Question 43Anesthesiology

A patient with a pheochromocytoma is undergoing resection. Which intraoperative event most commonly precipitates severe hypertension?

  1. Use of a volatile anesthetic alone
  2. Induction of hypothermia
  3. Administration of a beta-blocker before alpha-blockade
  4. Tumor manipulation releasing catecholamines Correct answer.

Explanation

Surgical manipulation of the tumor releases stored catecholamines and produces hypertensive crises, so alpha-blockade must be established preoperatively and vasodilators are kept ready. Beta-blockade before alpha-blockade can cause unopposed alpha stimulation and is dangerous, but the most common precipitant during surgery is tumor handling.

Question 44Anesthesiology

A patient with a full stomach requires induction. Which maneuver best reduces the risk of aspiration during induction?

  1. Placement in the supine position with the head elevated 10 degrees
  2. Administration of a large fluid bolus before induction
  3. Deep inhalational induction with spontaneous ventilation
  4. Application of cricoid pressure with rapid sequence induction and avoidance of mask ventilation Correct answer.

Explanation

Rapid sequence induction with cricoid pressure and avoidance of positive-pressure mask ventilation reduces gastric insufflation and aspiration risk in a patient with a full stomach. Deep inhalational induction is reserved for situations where intubation is predicted to be difficult and is not the standard approach for a full stomach.

Question 45Anesthesiology

A patient with a suspected difficult airway is being mask-ventilated after induction. Which finding most strongly predicts difficulty with mask ventilation?

  1. Age over 55 years with a body mass index over 26 and presence of a beard Correct answer.
  2. Presence of full dentition
  3. Mallampati class I with a thyromental distance of 7 cm
  4. History of a previous uncomplicated intubation

Explanation

The mnemonic MOANS identifies predictors of difficult mask ventilation: mask seal problems (beard), obesity, age over 55, no teeth, and snoring or stiff lungs. The combination of older age, elevated BMI, and a beard is a strong predictor.

Question 46Anesthesiology

A patient with myasthenia gravis is undergoing thymectomy. Which consideration regarding neuromuscular blockade is most accurate?

  1. The patient is sensitive to nondepolarizing relaxants and may require reduced doses with careful monitoring Correct answer.
  2. Succinylcholine is contraindicated because of receptor upregulation
  3. Neuromuscular blockade should be avoided entirely
  4. The patient is resistant to nondepolarizing relaxants and requires higher doses

Explanation

Myasthenia gravis involves reduced numbers of acetylcholine receptors, so patients are sensitive to nondepolarizing relaxants and require smaller doses with quantitative monitoring. Succinylcholine can be used but has an unpredictable response; blockade is not absolutely avoided.

Question 47Anesthesiology

A patient requires reversal of deep rocuronium blockade and neostigmine is contraindicated. Which agent is most appropriate?

  1. Neostigmine with glycopyrrolate
  2. Edrophonium
  3. Sugammadex Correct answer.
  4. Physostigmine

Explanation

Sugammadex is a modified gamma-cyclodextrin that encapsulates rocuronium and reverses even deep blockade rapidly without relying on acetylcholinesterase inhibition. The other agents are cholinesterase inhibitors and are unsuitable when neostigmine is contraindicated.

Question 48Anesthesiology

A patient with a known pseudocholinesterase deficiency receives succinylcholine. Which clinical course is expected?

  1. Paradoxical hypertension and tachycardia
  2. Prolonged paralysis lasting hours, requiring continued sedation and mechanical ventilation Correct answer.
  3. Paralysis lasting 3 to 5 minutes, similar to a normal patient
  4. Immediate hyperkalemic cardiac arrest

Explanation

Atypical or deficient pseudocholinesterase cannot rapidly hydrolyze succinylcholine, so paralysis can persist for hours until the drug is redistributed and slowly eliminated. Management is prolonged sedation, ventilation, and monitoring rather than redosing relaxants.

Question 49Anesthesiology

During one-lung ventilation, hypoxemia develops despite 100% oxygen. Which maneuver is most likely to improve oxygenation?

  1. Increasing the tidal volume delivered to the ventilated lung to 12 mL/kg
  2. Increasing the respiratory rate to 30 breaths per minute
  3. Discontinuing PEEP on the ventilated lung
  4. Application of continuous positive airway pressure to the non-ventilated lung and PEEP to the dependent lung Correct answer.

Explanation

CPAP to the non-dependent, non-ventilated lung recruits it for gas exchange, and modest PEEP to the dependent lung reduces atelectasis; together they improve oxygenation during one-lung ventilation. Large tidal volumes increase the risk of lung injury, and removing PEEP worsens atelectasis.

Question 50Anesthesiology

A patient with a known difficult airway and a full stomach requires emergency surgery. Which approach best balances aspiration risk and airway difficulty?

  1. Blind nasal intubation after deep sedation
  2. Awake fiberoptic intubation with topical anesthesia while maintaining spontaneous ventilation Correct answer.
  3. Rapid sequence induction with succinylcholine and cricoid pressure
  4. Inhalational induction with a laryngeal mask airway

Explanation

When both a difficult airway and aspiration risk are present, an awake technique that preserves spontaneous ventilation allows the airway to be secured before inducing anesthesia and losing protective reflexes. Rapid sequence induction risks a cannot-intubate cannot-ventilate situation, and deep sedation or a laryngeal mask does not protect against aspiration.