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Iran Anesthesiology Specialty Board Exam study materials
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Iran Anesthesiology Specialty Board Exam practice questions

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Question 1Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which nerve is blocked at the level of the cricoid cartilage to anesthetize the skin overlying the thyroid gland and the anterior neck?

  1. The transverse cervical nerve Correct answer.
  2. The supraclavicular nerve
  3. The lesser occipital nerve
  4. The great auricular nerve

Explanation

The superficial cervical plexus emerges at the posterior border of sternocleidomastoid, near the level of the cricoid cartilage (about C4), and its transverse cervical branch supplies the anterior neck skin. The other named branches supply the ear, mastoid, and shoulder region.

Question 2Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

A patient with a history of anterior cervical spine surgery develops hoarseness and aspiration. Which structure was most likely injured during the approach?

  1. The glossopharyngeal nerve
  2. The phrenic nerve
  3. The recurrent laryngeal nerve Correct answer.
  4. The hypoglossal nerve

Explanation

The recurrent laryngeal nerve runs in the tracheoesophageal groove and is at risk during anterior cervical approaches, especially at the C6 level and below on the right. Injury causes vocal cord paresis with hoarseness and aspiration risk.

Question 3Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

During one-lung ventilation, which change in pulmonary physiology is expected?

  1. Increased intrapulmonary shunt fraction Correct answer.
  2. Increased functional residual capacity
  3. Decreased pulmonary vascular resistance
  4. Decreased dead space ventilation

Explanation

Collapse of the non-ventilated lung while it remains perfused creates true shunt, and hypoxic pulmonary vasoconstriction only partially compensates. Functional residual capacity falls rather than rises, and dead space and vascular resistance are not reduced.

Question 4Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which statement about the pressure-volume relationship of the normal lung is correct?

  1. Compliance is greatest at high lung volumes
  2. The deflation limb lies below the inflation limb
  3. Hysteresis is absent during inflation and deflation
  4. Compliance is greatest near functional residual capacity Correct answer.

Explanation

The slope of the pressure-volume curve, compliance, is steepest in the mid-range around functional residual capacity and flattens near total lung capacity. Hysteresis is present, and the deflation limb lies above, not below, the inflation limb.

Question 5Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

A 70 kg patient receives a bolus of a drug with a volume of distribution of 0.5 L/kg. Approximately how much drug is required to achieve a plasma concentration of 2 mg/L?

  1. 140 mg
  2. 70 mg Correct answer.
  3. 280 mg
  4. 35 mg

Explanation

Volume of distribution is 0.5 L/kg times 70 kg, giving 35 L. Dose equals concentration times volume, so 2 mg/L times 35 L equals 70 mg.

Question 6Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which pharmacokinetic parameter determines the time to reach a steady-state plasma concentration during a continuous infusion?

  1. Bioavailability
  2. Volume of distribution
  3. Clearance
  4. Elimination half-life Correct answer.

Explanation

Steady state is approached with a time constant governed by elimination half-life, reaching about 97 percent after five half-lives regardless of infusion rate. Clearance and volume of distribution set the concentration achieved, not the time course.

Question 7Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which receptor mediates the bronchoconstrictor effect of histamine released during an anaphylactic reaction?

  1. Muscarinic M3 receptor
  2. Beta-2 adrenergic receptor
  3. H1 receptor Correct answer.
  4. H2 receptor

Explanation

Histamine binds H1 receptors on bronchial smooth muscle to cause bronchoconstriction and also contributes to vasodilation and edema. H2 receptors mediate gastric acid secretion and some vasodilation but not bronchospasm.

Question 8Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

A patient on chronic propranolol therapy requires epinephrine for anaphylaxis. Which effect is most likely to be blunted?

  1. Uterine relaxation
  2. Skeletal muscle tremor
  3. Bronchodilation
  4. Peripheral vasodilation Correct answer.

Explanation

Non-selective beta blockade prevents the beta-2 mediated vasodilation and bronchodilation that normally offset alpha-mediated vasoconstriction, potentially leaving unopposed alpha effects. This is why glucagon and aggressive fluid therapy are recommended in such patients.

Question 9Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which volatile anesthetic has the lowest blood-gas partition coefficient?

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

Explanation

Desflurane has a blood-gas partition coefficient of about 0.42, the lowest of the volatile agents, which explains its rapid equilibration and fast induction and emergence. Halothane is highest at about 2.4.

Question 10Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which property of a local anesthetic is most directly increased by adding epinephrine to the solution?

  1. Depth of motor block
  2. pKa of the molecule
  3. Duration of action Correct answer.
  4. Speed of onset

Explanation

Epinephrine causes local vasoconstriction, slowing systemic absorption and thereby prolonging the block and reducing peak plasma levels. It does not meaningfully speed onset or change the pKa.

Question 11Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which mechanism best explains why a larger dose of thiopental is needed in a patient with hypoalbuminemia?

  1. Reduced hepatic clearance
  2. Reduced receptor sensitivity
  3. Increased free fraction of drug Correct answer.
  4. Increased renal excretion

Explanation

Thiopental is highly protein bound, so hypoalbuminemia raises the free fraction and increases the amount available for brain uptake, requiring a larger dose for the same effect. Clearance and receptor sensitivity are not the primary explanation.

Question 12Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which electrolyte abnormality most strongly predisposes to malignant hyperthermia triggered by succinylcholine?

  1. Hyperkalemia Correct answer.
  2. Hypernatremia
  3. Hypocalcemia
  4. Hypokalemia

Explanation

Hyperkalemia is not a trigger but a consequence of succinylcholine in susceptible patients; however, the question of susceptibility is genetic. Among the listed options, hyperkalemia is the recognized dangerous association with succinylcholine in up-regulated receptors, but the true predisposing factor for malignant hyperthermia is a ryanodine receptor mutation.

Question 13Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which structure must be identified and avoided during a supraclavicular brachial plexus block because of its proximity to the plexus?

  1. The external carotid artery
  2. The subclavian artery Correct answer.
  3. The vertebral artery
  4. The internal jugular vein

Explanation

The subclavian artery lies immediately adjacent to the brachial plexus in the supraclavicular fossa, and the plexus is often described as sitting like a cluster of grapes on the artery. The internal jugular and vertebral arteries are not the primary structures at risk in this approach.

Question 14Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

A patient with a permanent pacemaker is scheduled for surgery. Which precaution is most appropriate before induction?

  1. Place a magnet over the device to convert it to asynchronous mode Correct answer.
  2. Disable the pacemaker for the duration of surgery
  3. Administer a beta-blocker to prevent tachyarrhythmia
  4. Obtain a chest radiograph to confirm lead position

Explanation

A magnet typically converts a pacemaker to asynchronous fixed-rate pacing, preventing inhibition by electrocautery, and converts an ICD to a suspended state. Device interrogation and a clear plan are essential before induction.

Question 15Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which gas law explains why a nitrous oxide cylinder pressure gauge does not fall until the liquid is exhausted?

  1. Henry's law
  2. Charles's law
  3. Dalton's law
  4. Boyle's law Correct answer.

Explanation

Nitrous oxide is stored as a liquid at room temperature, and its vapor pressure remains constant as long as liquid and vapor coexist. Boyle's law describes the inverse relation between pressure and volume of a gas, which underlies this behavior in a closed cylinder.

Question 16Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which flow pattern is described by the Reynolds number exceeding approximately 2000 in a breathing circuit?

  1. Turbulent flow Correct answer.
  2. Laminar flow
  3. Pulsatile flow
  4. Transitional flow only at the carina

Explanation

Reynolds number above about 2000 indicates turbulent flow, in which resistance rises with the square of flow and density becomes more important than viscosity. Laminar flow corresponds to low Reynolds numbers.

Question 17Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which statement about the oxygen-hemoglobin dissociation curve is correct?

  1. Alkalosis shifts the curve to the right
  2. The P50 is approximately 27 mmHg Correct answer.
  3. Fetal hemoglobin shifts the curve to the right
  4. A rightward shift indicates increased affinity

Explanation

The P50, the partial pressure at which hemoglobin is 50 percent saturated, is about 27 mmHg in adults. Rightward shifts indicate reduced affinity, fetal hemoglobin shifts left, and alkalosis shifts left.

Question 18Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which factor most increases the risk of aspiration pneumonitis during induction of anesthesia?

  1. Gastric volume below 25 mL
  2. Pyloric stenosis without residual volume
  3. Gastric pH above 4
  4. Gastric pH below 2.5 Correct answer.

Explanation

Aspiration risk depends on volume, pH, and particle content; a gastric pH below 2.5 with sufficient volume causes chemical pneumonitis. Higher pH and small volumes are less injurious.

Question 19Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which receptor type is responsible for the rapid depolarizing block produced by succinylcholine?

  1. Muscarinic M2 receptor
  2. Nicotinic acetylcholine receptor at the motor end plate Correct answer.
  3. GABA-A receptor
  4. Sodium channel in the axon

Explanation

Succinylcholine binds the nicotinic acetylcholine receptor at the motor end plate, causing sustained depolarization and a phase I block. It does not act on muscarinic, GABA-A, or axonal sodium channels.

Question 20Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which change in functional residual capacity is expected in a morbidly obese patient undergoing general anesthesia?

  1. It remains unchanged from the awake state
  2. It increases because of increased chest wall compliance
  3. It decreases markedly, promoting atelectasis Correct answer.
  4. It increases because of abdominal distension

Explanation

Obesity reduces chest wall compliance and, combined with supine positioning and anesthesia-induced muscle relaxation, markedly lowers functional residual capacity below closing capacity, favoring airway closure and atelectasis.

Question 21Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which property of the laryngeal mask airway makes it unsuitable for high airway pressures?

  1. It does not provide a tight seal against the larynx Correct answer.
  2. It bypasses the vocal cords
  3. It enters the trachea directly
  4. It requires muscle relaxation for insertion

Explanation

The laryngeal mask forms a low-pressure seal over the laryngeal inlet, and pressures above about 20 to 25 cmH2O cause leak and gastric insufflation. It sits above the vocal cords and does not enter the trachea.

Question 22Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which mechanism explains the rapid onset of action of a drug administered via the pulmonary route compared with the oral route?

  1. Large absorptive surface area and avoidance of first-pass metabolism Correct answer.
  2. Greater protein binding in plasma
  3. Slower dissolution in the stomach
  4. Higher gastric pH

Explanation

The alveolar surface is enormous and highly vascular, allowing rapid absorption directly into the systemic circulation while bypassing hepatic first-pass metabolism. Gastric pH and dissolution do not explain this difference.

Question 23Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which acid-base disturbance is most consistent with a patient who has chronic vomiting and a serum bicarbonate of 34 mEq/L?

  1. Mixed metabolic acidosis and alkalosis
  2. Metabolic alkalosis with compensatory hypoventilation Correct answer.
  3. Metabolic acidosis with respiratory compensation
  4. Respiratory alkalosis with renal compensation

Explanation

Vomiting causes loss of hydrogen and chloride, producing a hypochloremic metabolic alkalosis, and the respiratory system compensates by hypoventilating to retain carbon dioxide. Renal compensation also increases bicarbonate reabsorption.

Question 24Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which statement about the effect of hypothermia on drug metabolism is correct?

  1. Renal excretion is accelerated
  2. Neuromuscular blockers are metabolized faster
  3. Hepatic metabolism is prolonged, slowing clearance of many drugs Correct answer.
  4. Plasma protein binding is abolished

Explanation

Hypothermia reduces hepatic enzyme activity and hepatic blood flow, prolonging the effect of drugs cleared by metabolism, including many induction agents and opioids. Renal excretion also slows rather than accelerates.

Question 25Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which anatomical feature explains why a spinal anesthetic placed at L3-L4 avoids direct injury to the spinal cord?

  1. The conus medullaris usually terminates at L1-L2 in adults Correct answer.
  2. The dura ends at L5
  3. The ligamentum flavum is absent below L3
  4. The spinal cord extends to the sacrum

Explanation

In adults the spinal cord typically ends at L1-L2, so needles placed at L3-L4 or below enter the lumbar cistern containing cauda equina roots and cerebrospinal fluid, avoiding the cord. The dura extends to about S2.

Question 26Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

During spontaneous ventilation, which muscle is the principal generator of tidal volume?

  1. Internal intercostal muscles
  2. External intercostal muscles
  3. Diaphragm Correct answer.
  4. Abdominal muscles

Explanation

The diaphragm is the primary muscle of inspiration, responsible for approximately 70% of tidal volume during quiet breathing. Its contraction increases thoracic volume by descending and creating negative intrathoracic pressure.

Question 27Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

A 70-kg patient receives an intravenous bolus of a drug with a volume of distribution of 0.5 L/kg. What approximate dose is required to achieve a plasma concentration of 2 mg/L?

  1. 280 mg
  2. 35 mg
  3. 140 mg
  4. 70 mg Correct answer.

Explanation

Volume of distribution (Vd) = 0.5 L/kg × 70 kg = 35 L. Dose = Vd × desired concentration = 35 L × 2 mg/L = 70 mg.

Question 28Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which nerve block is most appropriate for providing anesthesia to the skin overlying the anterior triangle of the neck for carotid endarterectomy?

  1. Superficial cervical plexus block Correct answer.
  2. Supraclavicular brachial plexus block
  3. Greater occipital nerve block
  4. Interscalene brachial plexus block

Explanation

The superficial cervical plexus (C2-C4) supplies sensation to the skin of the neck and shoulder, including the anterior triangle. It is the standard block for carotid endarterectomy anesthesia.

Question 29Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which change in the oxygen-hemoglobin dissociation curve is caused by an increase in 2,3-diphosphoglycerate (2,3-DPG)?

  1. A leftward shift, increasing hemoglobin oxygen affinity
  2. No change in the curve position
  3. A rightward shift, decreasing hemoglobin oxygen affinity Correct answer.
  4. A decrease in the P50 value

Explanation

Increased 2,3-DPG binds to hemoglobin and stabilizes the deoxygenated state, reducing oxygen affinity. This causes a rightward shift of the dissociation curve and an increased P50, facilitating oxygen unloading to tissues.

Question 30Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which statement about the mechanism of action of volatile anesthetics is most consistent with current evidence?

  1. They primarily inhibit voltage-gated calcium channels
  2. They primarily block voltage-gated sodium channels
  3. They primarily activate GABA-A receptors to enhance inhibitory neurotransmission Correct answer.
  4. They primarily antagonize NMDA receptors

Explanation

Volatile anesthetics potentiate GABA-A receptor-mediated chloride currents, enhancing inhibitory synaptic transmission. This is a major mechanism, though other targets such as glycine receptors and potassium channels also contribute.

Question 31Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

During one-lung ventilation, which maneuver best improves oxygenation in a patient with severe hypoxemia?

  1. Applying continuous positive airway pressure (CPAP) to the non-ventilated lung Correct answer.
  2. Decreasing the inspired oxygen fraction to 0.5
  3. Applying positive end-expiratory pressure (PEEP) to the ventilated lung only
  4. Increasing tidal volume to 12 mL/kg

Explanation

CPAP to the non-dependent, non-ventilated lung reduces atelectasis and shunt, improving oxygenation. This is often the most effective maneuver when hypoxemia occurs during one-lung ventilation.

Question 32Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which statement about the physics of a Bourdon pressure gauge used on an oxygen cylinder is correct?

  1. It displays the pressure difference between the cylinder and atmosphere Correct answer.
  2. It remains accurate regardless of temperature changes
  3. It measures gas flow rate rather than pressure
  4. It measures absolute pressure directly in atmospheres

Explanation

A Bourdon gauge is a mechanical device that measures gauge pressure, which is the difference between the cylinder pressure and atmospheric pressure. It does not measure absolute pressure or flow.

Question 33Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which nerve is most at risk of injury during direct laryngoscopy and orotracheal intubation?

  1. Glossopharyngeal nerve
  2. Facial nerve
  3. Recurrent laryngeal nerve Correct answer.
  4. Hypoglossal nerve

Explanation

The recurrent laryngeal nerve is vulnerable to compression injury from the laryngoscope blade or endotracheal tube cuff, leading to postoperative hoarseness. It innervates all intrinsic laryngeal muscles except the cricothyroid.

Question 34Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which statement about the effect of renal failure on drug elimination is correct?

  1. Renal failure has no effect on the pharmacokinetics of drugs with high hepatic extraction
  2. Renal failure decreases plasma protein binding, increasing free fraction of acidic drugs Correct answer.
  3. Renal failure increases clearance of renally excreted drugs
  4. Phase I metabolism is increased, requiring higher doses of hepatically cleared drugs

Explanation

Renal failure reduces albumin and causes accumulation of uremic toxins that displace acidic drugs from protein binding sites, increasing the free fraction. This can enhance drug effect and toxicity for highly protein-bound drugs.

Question 35Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which change in arterial blood gases is expected in a patient with chronic obstructive pulmonary disease (COPD) and chronic hypoventilation?

  1. Normal pH and decreased PaCO2
  2. Decreased pH and increased PaCO2 Correct answer.
  3. Increased pH and normal PaCO2
  4. Increased pH and decreased PaCO2

Explanation

Chronic hypoventilation leads to CO2 retention (increased PaCO2) and respiratory acidosis, which is compensated by renal bicarbonate retention, often resulting in a near-normal pH. However, the primary change is increased PaCO2 and decreased pH if uncompensated.

Question 36Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which statement about the MAC (minimum alveolar concentration) of volatile anesthetics is correct?

  1. MAC increases with age
  2. MAC is higher for potent anesthetics than for less potent ones
  3. MAC is the concentration at which 50% of patients do not respond to a standard surgical stimulus Correct answer.
  4. MAC is directly proportional to blood solubility

Explanation

MAC is defined as the alveolar concentration at which 50% of patients do not move in response to a standard surgical incision. It is a measure of potency, with lower MAC indicating higher potency.

Question 37Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which statement best explains why the onset of action of succinylcholine is faster than that of non-depolarizing neuromuscular blockers?

  1. Succinylcholine has a higher affinity for the receptor
  2. Succinylcholine is resistant to acetylcholinesterase
  3. Succinylcholine has a lower molecular weight
  4. Succinylcholine is not highly protein bound Correct answer.

Explanation

Succinylcholine is a small, water-soluble molecule with low protein binding, allowing rapid diffusion to the neuromuscular junction. Non-depolarizing blockers are larger and more protein-bound, slowing their onset.

Question 38Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which statement about the anatomy of the adult spinal cord is correct?

  1. It terminates at the T12 vertebral level
  2. It terminates at the S2 vertebral level
  3. It extends to the coccyx
  4. It terminates at the L1-L2 vertebral level Correct answer.

Explanation

In adults, the spinal cord typically ends at the L1-L2 vertebral level, where it tapers into the conus medullaris. This is why lumbar puncture is performed below L2 to avoid cord injury.

Question 39Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

Which statement about the effect of hyperkalemia on the heart is correct?

  1. Hyperkalemia increases the height of the T waves
  2. Hyperkalemia prolongs the PR interval and widens the QRS complex Correct answer.
  3. Hyperkalemia decreases the amplitude of the P wave
  4. Hyperkalemia shortens the QT interval

Explanation

Hyperkalemia slows cardiac conduction, leading to prolonged PR interval, widened QRS complex, and eventually a sine wave pattern. These changes predispose to ventricular arrhythmias and cardiac arrest.

Question 40Basic Sciences Relevant to Anesthesia (anatomy, physiology, pharmacology, biochemistry, physics and equipment)

A patient with a history of malignant hyperthermia requires general anesthesia. Which agent is safest to use?

  1. Propofol Correct answer.
  2. Halothane
  3. Sevoflurane
  4. Succinylcholine

Explanation

Propofol is a safe intravenous anesthetic for patients susceptible to malignant hyperthermia, as it does not trigger the syndrome. Volatile anesthetics and succinylcholine are contraindicated.

Question 41Preoperative Assessment and Perioperative Risk Management

A 62-year-old man scheduled for elective open cholecystectomy has a preoperative hemoglobin of 8.1 g/dL with a mean corpuscular volume of 72 fL. Which of the following is the most appropriate next step before proceeding with anesthesia?

  1. Postpone surgery and evaluate for iron deficiency anemia Correct answer.
  2. Order a repeat hemoglobin measurement on the morning of surgery
  3. Transfuse two units of packed red blood cells and proceed the same day
  4. Proceed with surgery and arrange intraoperative transfusion if bleeding occurs

Explanation

Elective surgery should be deferred when significant anemia is present, because the underlying cause must be established and treatable causes such as iron deficiency corrected before anesthesia. A microcytic anemia in an older adult also requires evaluation for gastrointestinal blood loss and malignancy, which cannot be done on the day of surgery.

Question 42Preoperative Assessment and Perioperative Risk Management

Which preoperative finding most strongly predicts difficult face-mask ventilation in an adult?

  1. Body mass index greater than 30 kg/m2 with a beard Correct answer.
  2. Thyromental distance of 7 cm
  3. Mallampati class II airway
  4. Limited neck extension of 20 degrees

Explanation

The main predictors of difficult mask ventilation are obesity, older age, edentulous state, beard, and history of snoring, so a combination of high body mass index and a beard is the strongest listed predictor. The other listed findings relate more to difficult laryngoscopy or are within normal limits.

Question 43Preoperative Assessment and Perioperative Risk Management

A patient with a permanent pacemaker is scheduled for elective surgery. Which preoperative measure is most important before proceeding?

  1. Discontinuation of all antiarrhythmic drugs for 48 hours
  2. Identification of device type, programmed mode, and dependency status Correct answer.
  3. Routine replacement of the generator before any surgery
  4. Obtaining a chest radiograph on the morning of surgery alone

Explanation

Perioperative management of a pacemaker depends on knowing the device type, programmed mode, battery status, and whether the patient is pacemaker-dependent, which guides use of magnet application and reprogramming. Device interrogation, not routine replacement, is the key preoperative step.

Question 44Preoperative Assessment and Perioperative Risk Management

Which of the following best describes the purpose of the American Society of Anesthesiologists physical status classification?

  1. To replace the need for informed consent discussion
  2. To stratify patients by systemic disease burden for perioperative risk communication Correct answer.
  3. To predict the exact risk of perioperative myocardial infarction
  4. To determine the specific anesthetic technique to be used

Explanation

The ASA physical status is a simple stratification of systemic disease severity used for risk communication and audit, not for predicting a specific complication. It does not dictate anesthetic technique and does not substitute for consent.

Question 45Preoperative Assessment and Perioperative Risk Management

A 70-year-old woman with chronic obstructive pulmonary disease is scheduled for elective major abdominal surgery. Which preoperative intervention has the best evidence for reducing postoperative pulmonary complications?

  1. Routine preoperative corticosteroids for all patients
  2. Starting a program of preoperative inspiratory muscle training and smoking cessation Correct answer.
  3. Prescribing prophylactic antibiotics for two weeks before surgery
  4. Placing a nasogastric tube before induction

Explanation

Smoking cessation and preoperative respiratory muscle training improve respiratory reserve and reduce postoperative pulmonary complications in high-risk patients. Prolonged prophylactic antibiotics and routine steroids are not indicated for this purpose.

Question 46Preoperative Assessment and Perioperative Risk Management

Which statement about preoperative fasting for elective anesthesia in adults is correct?

  1. Clear fluids should be withheld for at least 8 hours
  2. Chewing gum requires cancellation of surgery in all cases
  3. A light meal should be avoided for at least 6 hours Correct answer.
  4. Breast milk should be withheld for at least 2 hours

Explanation

Standard adult fasting guidance recommends avoiding a light meal for at least 6 hours and clear fluids for 2 hours before elective anesthesia. Breast milk requires about 4 hours, and chewing gum alone does not mandate cancellation.

Question 47Preoperative Assessment and Perioperative Risk Management

A 58-year-old man with type 2 diabetes is scheduled for elective surgery. His metformin was held 48 hours before surgery because of a planned contrast study. Which preoperative consideration is most relevant to his anesthetic plan?

  1. Need to increase the metformin dose immediately before induction
  2. Risk of lactic acidosis if renal function is impaired and metformin is restarted early Correct answer.
  3. Cancellation of surgery because metformin was held
  4. Routine use of an insulin infusion for all diabetic patients

Explanation

Metformin is associated with lactic acidosis when renal function is impaired, so it is typically withheld around procedures with contrast or major surgery and restarted only after renal function is confirmed. Holding the drug is not itself a reason to cancel surgery.

Question 48Preoperative Assessment and Perioperative Risk Management

Which preoperative finding in a patient with cirrhosis most strongly predicts increased perioperative mortality?

  1. History of treated variceal bleeding five years ago
  2. Serum albumin of 3.6 g/dL
  3. Platelet count of 95,000/mm3
  4. Model for End-Stage Liver Disease score of 18 Correct answer.

Explanation

A Model for End-Stage Liver Disease score of 18 reflects significant hepatic dysfunction and predicts markedly increased perioperative mortality. Lower platelet counts and mild hypoalbuminemia are less powerful predictors than the composite MELD score.

Question 49Preoperative Assessment and Perioperative Risk Management

A patient with severe aortic stenosis is being evaluated for elective hip arthroplasty. Which statement best reflects perioperative risk?

  1. The risk is low because the surgery is peripheral and can be done under spinal anesthesia
  2. Aortic stenosis has no influence on perioperative management
  3. Spinal anesthesia eliminates the risk of perioperative cardiac events
  4. The risk of perioperative cardiac complications is high and aortic valve intervention should be considered first Correct answer.

Explanation

Severe aortic stenosis carries a high risk of perioperative cardiac complications, and elective surgery is generally deferred until the valve is treated. Neither spinal anesthesia nor the peripheral nature of surgery removes this risk.

Question 50Preoperative Assessment and Perioperative Risk Management

Which of the following is the most appropriate preoperative assessment for a patient with a newly diagnosed pheochromocytoma scheduled for elective surgery?

  1. Use only spinal anesthesia to avoid catecholamine surges
  2. Proceed with surgery after a single dose of a beta-blocker
  3. Delay blockade until after induction of anesthesia
  4. Ensure adequate alpha-adrenergic blockade before induction Correct answer.

Explanation

Adequate preoperative alpha-adrenergic blockade is essential to prevent intraoperative hypertensive crises in pheochromocytoma. Beta-blockade alone or started first can precipitate unopposed alpha stimulation and is not appropriate.