I85PREP
⌘ K
ABPS Anesthesiology (BCA) study materials
ABPS Anesthesiology (BCA) study resources

ABPS Anesthesiology (BCA) practice questions

One question at a time. Build your ABPS Anesthesiology (BCA) understanding.

First 50 of 200 questions. Each one lists the choices, the correct answer, and an explanation. The checker at the top of this page saves progress in this browser when it is available.

Continue in the practice tool above to load more questions, 50 at a time.

Question 1Basic Sciences: Physics, Physiology, Pharmacology, and Anatomy

Which unit is used to express electrical resistance?

  1. Henry
  2. Farad
  3. Siemens
  4. Ohm Correct answer.

Explanation

Resistance is the opposition to current flow and is measured in ohms, with the relationship V = IR. Capacitance is measured in farads, inductance in henries, and conductance in siemens.

Question 2Basic Sciences: Physics, Physiology, Pharmacology, and Anatomy

What is the approximate anatomical dead space of a healthy adult?

  1. 5 mL/kg
  2. 0.5 mL/kg
  3. 2 mL/kg Correct answer.
  4. 10 mL/kg

Explanation

Anatomical dead space is the volume of the conducting airways that does not participate in gas exchange. In a healthy adult it is approximately 2 mL/kg, or about 150 mL, as measured by the single-breath nitrogen washout technique.

Question 3Basic Sciences: Physics, Physiology, Pharmacology, and Anatomy

What does the minimum alveolar concentration (MAC) of an inhaled anesthetic represent?

  1. Concentration preventing movement in half of patients Correct answer.
  2. Concentration abolishing the cough reflex in half of patients
  3. Concentration producing amnesia in half of patients
  4. Concentration causing apnea in half of patients

Explanation

MAC is the alveolar concentration of an inhaled anesthetic at which 50% of patients do not move in response to a standard surgical stimulus. It is a measure of potency, so a lower MAC indicates a more potent agent.

Question 4Basic Sciences: Physics, Physiology, Pharmacology, and Anatomy

Local anesthetics interrupt nerve conduction primarily through which action?

  1. Potentiation of GABA-A receptor currents
  2. Inhibition of presynaptic calcium channels
  3. Activation of voltage-gated potassium channels
  4. Blockade of voltage-gated sodium channels Correct answer.

Explanation

Local anesthetics bind the intracellular side of voltage-gated sodium channels in the inactivated state, preventing the sodium influx required for depolarization. Small unmyelinated fibers are blocked first because they have shorter inter-node distances.

Question 5Basic Sciences: Physics, Physiology, Pharmacology, and Anatomy

The cricothyroid membrane is located between which two structures?

  1. The thyroid cartilage and the cricoid cartilage Correct answer.
  2. The hyoid bone and the thyroid cartilage
  3. The cricoid cartilage and the first tracheal ring
  4. The arytenoid and the thyroid cartilages

Explanation

The cricothyroid membrane stretches between the inferior border of the thyroid cartilage and the superior border of the cricoid cartilage. It is the landmark used for emergency cricothyrotomy.

Question 6Basic Sciences: Physics, Physiology, Pharmacology, and Anatomy

The resting membrane potential of a typical neuron lies closest to the equilibrium potential of which ion?

  1. Potassium Correct answer.
  2. Sodium
  3. Calcium
  4. Chloride

Explanation

At rest the membrane is far more permeable to potassium than to sodium because of open potassium leak channels. The resting potential therefore sits near the potassium equilibrium potential, around −90 mV.

Question 7Basic Sciences: Physics, Physiology, Pharmacology, and Anatomy

Two alveoli of different radii share a common airway. In the absence of surfactant, why does the smaller alveolus tend to collapse into the larger one?

  1. Compliance is higher in the smaller alveolus
  2. Laplacian pressure is higher in the smaller alveolus Correct answer.
  3. Airflow resistance is lower in the smaller alveolus
  4. Surface tension is lower in the smaller alveolus

Explanation

By Laplace's law, the distending pressure for a sphere equals 2T/r, so a smaller radius generates a higher collapsing pressure at the same surface tension. Surfactant lowers surface tension more in small alveoli, which stabilizes them and prevents collapse.

Question 8Basic Sciences: Physics, Physiology, Pharmacology, and Anatomy

A respiratory unit has a compliance of 0.05 L/cmH2O and a resistance of 2 cmH2O/L/s. What is its time constant?

  1. 0.40 s
  2. 0.025 s
  3. 0.10 s Correct answer.
  4. 2.50 s

Explanation

The time constant of a respiratory unit is the product of compliance and resistance: 0.05 L/cmH2O × 2 cmH2O/L/s = 0.1 s. After one time constant, about 63% of a step change in volume or pressure has occurred.

Question 9Basic Sciences: Physics, Physiology, Pharmacology, and Anatomy

Why is the context-sensitive half-time of remifentanil short and essentially constant regardless of infusion duration?

  1. Renal excretion of unchanged drug
  2. Rapid redistribution into adipose tissue
  3. Hydrolysis by nonspecific plasma and tissue esterases Correct answer.
  4. Hepatic metabolism by CYP3A4

Explanation

Remifentanil is cleared by nonspecific esterases in plasma and tissues, so its offset is independent of hepatic and renal function and of infusion duration. This produces a context-insensitive half-time of about 3 to 5 minutes.

Question 10Basic Sciences: Physics, Physiology, Pharmacology, and Anatomy

Approximately what fraction of a drug remains in the body after four elimination half-lives?

  1. 12.5%
  2. 3.125%
  3. 25%
  4. 6.25% Correct answer.

Explanation

Each half-life halves the remaining amount, so after four half-lives the fraction remaining is (1/2)^4 = 1/16, or 6.25%. Roughly 94% of the drug has been eliminated by that point.

Question 11Basic Sciences: Physics, Physiology, Pharmacology, and Anatomy

Pulse oximetry estimates arterial oxygen saturation using which principle?

  1. Differential absorption of red and infrared light Correct answer.
  2. Absorption of ultraviolet light by carboxyhemoglobin
  3. Measurement of arterial partial pressure of oxygen
  4. Doppler shift of reflected ultrasound waves

Explanation

Pulse oximetry applies the Beer-Lambert law and compares light absorption at red and infrared wavelengths. The pulsatile component isolates arterial blood, and the ratio of absorption is converted into a saturation value.

Question 12Basic Sciences: Physics, Physiology, Pharmacology, and Anatomy

What pattern does train-of-four monitoring show during a phase I succinylcholine block?

  1. A train-of-four ratio below 0.7
  2. Progressive fade of all four responses
  3. Post-tetanic potentiation after tetanus
  4. Equal depression of all four twitches Correct answer.

Explanation

Phase I depolarizing block produces equal depression of all four train-of-four responses without fade, because the endplate remains depolarized and additional acetylcholine cannot generate further endplate potentials. Fade appears with phase II block or nondepolarizing blockade.

Question 13Basic Sciences: Physics, Physiology, Pharmacology, and Anatomy

Hypotension after a high spinal anesthetic is mainly caused by which mechanism?

  1. Direct myocardial depression from the local anesthetic
  2. Sympathetic blockade with venodilation and reduced venous return Correct answer.
  3. Isolated vagal stimulation causing bradycardia
  4. Adrenal blockade reducing circulating catecholamines

Explanation

High neuraxial block interrupts sympathetic fibers from T1 to L2, producing arterial and venous dilation with falls in systemic vascular resistance and venous return. Treatment consists of fluid loading plus a vasopressor such as phenylephrine.

Question 14Basic Sciences: Physics, Physiology, Pharmacology, and Anatomy

Cerebral blood flow is most strongly and directly influenced by which variable within the normal physiologic range?

  1. Arterial oxygen tension
  2. Arterial carbon dioxide tension Correct answer.
  3. Jugular venous oxygen saturation
  4. Mean arterial pressure within the autoregulatory range

Explanation

Cerebral blood flow changes steeply with arterial CO2 tension, by roughly 2 to 4% per mmHg in the normal range. This CO2 reactivity is exploited clinically when hyperventilation is used to lower intracranial pressure.

Question 15Basic Sciences: Physics, Physiology, Pharmacology, and Anatomy

Which formula correctly expresses arterial oxygen content?

  1. 1.34 × Hb × SaO2 + 0.03 × PaCO2
  2. 0.003 × Hb × SaO2 + 1.34 × PaO2
  3. 1.34 × Hb × SaO2 + 0.003 × PaO2 Correct answer.
  4. 1.34 × Hb × PaO2 + 0.003 × SaO2

Explanation

Oxygen content combines the bound and dissolved fractions: 1.34 mL O2 per gram of hemoglobin times hemoglobin concentration times saturation, plus 0.003 mL O2 per mmHg times PaO2. At sea level the dissolved fraction contributes only a small amount.

Question 16Basic Sciences: Physics, Physiology, Pharmacology, and Anatomy

The left recurrent laryngeal nerve loops around which structure?

  1. The cricoid cartilage
  2. The thyrohyoid membrane
  3. The right subclavian artery
  4. The aortic arch near the ligamentum arteriosum Correct answer.

Explanation

The left recurrent laryngeal nerve branches from the vagus and loops beneath the aortic arch adjacent to the ligamentum arteriosum. The right recurrent laryngeal nerve instead loops beneath the right subclavian artery.

Question 17Basic Sciences: Physics, Physiology, Pharmacology, and Anatomy

Potency of a drug is best described by which parameter?

  1. The ratio of toxic to therapeutic dose
  2. The slope of the dose-response relationship
  3. The maximal effect achievable at any dose
  4. The dose producing 50% of maximal effect Correct answer.

Explanation

Potency refers to the concentration or dose that produces a given effect, conventionally 50% of maximal effect (ED50 or EC50). Efficacy is the maximal response, while the slope describes the steepness of the curve.

Question 18Basic Sciences: Physics, Physiology, Pharmacology, and Anatomy

Which route most completely avoids hepatic first-pass metabolism?

  1. Rectal administration
  2. Small-bowel administration
  3. Sublingual administration Correct answer.
  4. Oral ingestion

Explanation

Drug absorbed sublingually enters the venous drainage of the oral mucosa, which reaches the superior vena cava and bypasses the portal circulation. Oral, gastric, and small-bowel absorption all enter the portal vein and undergo hepatic first-pass metabolism.

Question 19Basic Sciences: Physics, Physiology, Pharmacology, and Anatomy

An arterial blood gas shows sodium 140 mmol/L, chloride 95 mmol/L, and bicarbonate 15 mmol/L. What are the anion gap and the delta ratio?

  1. Anion gap 30, delta ratio 2.0 Correct answer.
  2. Anion gap 30, delta ratio 1.0
  3. Anion gap 35, delta ratio 1.5
  4. Anion gap 20, delta ratio 1.0

Explanation

Anion gap = Na − Cl − HCO3 = 140 − 95 − 15 = 30. Delta ratio = (30 − 12)/(24 − 15) = 18/9 = 2.0, which suggests a concurrent metabolic alkalosis or chronic respiratory acidosis alongside the high-anion-gap acidosis.

Question 20Basic Sciences: Physics, Physiology, Pharmacology, and Anatomy

After an intravenous bolus of a lipophilic drug, what does the initial rapid fall in plasma concentration chiefly represent?

  1. Distribution into highly perfused tissues Correct answer.
  2. Saturation of plasma protein binding sites
  3. Hepatic first-pass metabolism
  4. Renal elimination of unchanged drug

Explanation

The early rapid decline after an intravenous bolus is the distribution phase as drug moves from plasma into well-perfused organs such as brain, heart, and liver. The slower terminal phase reflects elimination from the central compartment.

Question 21Anesthesia Equipment, Monitoring, and Instrumentation

Which physical principle is the basis of pulse oximetry?

  1. Measurement of dissolved oxygen partial pressure
  2. Doppler analysis of arterial blood flow velocity
  3. Differential light absorption by hemoglobin species Correct answer.
  4. Infrared detection of exhaled carbon dioxide

Explanation

Pulse oximetry compares the absorption of red and infrared light by oxygenated and deoxygenated hemoglobin. The pulsatile component isolates the arterial signal from venous and tissue absorption.

Question 22Anesthesia Equipment, Monitoring, and Instrumentation

A patient has just been intubated, and the capnograph shows no waveform after several breaths. What is the most likely explanation?

  1. Right mainstem bronchial intubation
  2. Exhausted carbon dioxide absorbent
  3. Esophageal placement of the tube Correct answer.
  4. Severe hyperventilation

Explanation

An esophageal tube has no contact with alveolar gas, so exhaled carbon dioxide is absent and the capnogram remains flat. Bronchial intubation and hyperventilation still produce a waveform, though with altered shape or amplitude.

Question 23Anesthesia Equipment, Monitoring, and Instrumentation

What is the approximate pressure inside a nitrous oxide cylinder at room temperature when it is partly full?

  1. 2200 psi
  2. 745 psi Correct answer.
  3. 1900 psi
  4. 625 psi

Explanation

Nitrous oxide is stored as a liquid-vapor mixture, and its cylinder pressure equals its vapor pressure at ambient temperature, about 745 psi. The pressure remains constant until all liquid has vaporized, so the gauge does not indicate how full the cylinder is.

Question 24Anesthesia Equipment, Monitoring, and Instrumentation

An adult blood pressure cuff that is too small for the patient's arm will typically:

  1. Underestimate systolic pressure
  2. Overestimate both pressures Correct answer.
  3. Have no effect on the reading
  4. Overestimate diastolic pressure only

Explanation

A cuff that is too narrow requires a higher inflation pressure to occlude the brachial artery, so both systolic and diastolic readings are falsely elevated. Cuff width should be about 40 percent of the arm circumference.

Question 25Anesthesia Equipment, Monitoring, and Instrumentation

What is the recommended intracuff pressure for a laryngeal mask airway?

  1. At least 200 cm H2O
  2. 120 to 150 cm H2O
  3. Less than 60 cm H2O Correct answer.
  4. 80 to 100 cm H2O

Explanation

The laryngeal mask cuff should be inflated to less than 60 cm H2O to reduce the risk of pharyngeal mucosal ischemia and nerve injury. A cuff pressure manometer is used rather than judging inflation by feel.

Question 26Anesthesia Equipment, Monitoring, and Instrumentation

During general anesthesia, which site most accurately reflects core body temperature?

  1. Rectum
  2. Distal esophagus Correct answer.
  3. Axilla
  4. Forehead skin

Explanation

The distal esophagus lies close to the heart and large vessels and tracks core temperature rapidly. Rectal temperature lags behind rapid changes, and skin and axillary readings are influenced by peripheral temperature.

Question 27Anesthesia Equipment, Monitoring, and Instrumentation

In a variable-bypass vaporizer, turning the concentration dial directly changes the:

  1. Total fresh gas flow entering the breathing circuit
  2. Pressure inside the breathing circuit
  3. Fraction of gas diverted through the vaporizer Correct answer.
  4. Temperature of the vaporizing chamber

Explanation

The dial controls a splitting valve that determines how much fresh gas flows through the vaporizing chamber and how much bypasses it. The resulting mixture establishes the delivered anesthetic concentration.

Question 28Anesthesia Equipment, Monitoring, and Instrumentation

During low-flow anesthesia, the inspired carbon dioxide concentration gradually rises. Which is the most likely cause?

  1. A depleted oxygen supply from the wall source
  2. Exhaustion of the carbon dioxide absorbent Correct answer.
  3. A leak in the inspiratory limb of the circuit
  4. A malfunctioning expiratory valve in the circuit

Explanation

When the absorbent can no longer remove carbon dioxide, exhaled gas is rebreathed and inspired carbon dioxide rises. This is an early and clinically important sign of absorbent exhaustion, especially at low fresh gas flows.

Question 29Anesthesia Equipment, Monitoring, and Instrumentation

How should the pressure leak test of an anesthesia machine be performed?

  1. Scavenging system disconnected from machine
  2. Y-piece occluded and APL valve closed Correct answer.
  3. Y-piece open and ventilator cycling
  4. Vaporizers turned to maximum output

Explanation

The breathing system is pressurized with the Y-piece occluded and the adjustable pressure-limiting valve closed. A stable pressure reading confirms that the circuit and machine have no significant leak.

Question 30Anesthesia Equipment, Monitoring, and Instrumentation

A train-of-four ratio of 0.9 after neuromuscular blockade indicates:

  1. Significant tetanic fade
  2. A phase II depolarizing block
  3. Adequate neuromuscular recovery Correct answer.
  4. Deep residual blockade

Explanation

A train-of-four ratio of at least 0.9 is the accepted threshold for adequate recovery of neuromuscular function. Ratios below this value are associated with residual paralysis and impaired airway reflexes.

Question 31Anesthesia Equipment, Monitoring, and Instrumentation

The oxygen flush valve on an anesthesia machine typically delivers:

  1. 100% oxygen only during inspiration
  2. 10 to 15 L/min of oxygen
  3. 2 to 4 L/min of oxygen
  4. 35 to 75 L/min at 50 psi Correct answer.

Explanation

The oxygen flush valve provides a high flow of oxygen, usually 35 to 75 L/min at a pipeline pressure near 50 psi. This flow bypasses the flowmeters and vaporizers and can rapidly fill the breathing circuit.

Question 32Anesthesia Equipment, Monitoring, and Instrumentation

What is the main function of the reservoir bag in an anesthesia scavenging system?

  1. To buffer transient increases in exhaled volume Correct answer.
  2. To filter waste anesthetic agent from the circuit
  3. To measure the exhaled tidal volume continuously
  4. To humidify the inspired gases before delivery

Explanation

The scavenging reservoir bag absorbs brief surges in exhaled gas flow and prevents excessive positive or negative pressure in the breathing circuit. It does not measure, humidify, or filter gas.

Question 33Anesthesia Equipment, Monitoring, and Instrumentation

A capnogram shows a slowly rising expiratory upstroke and a prolonged plateau. What does this suggest?

  1. Obstructive airway disease Correct answer.
  2. Circuit disconnection
  3. Esophageal intubation
  4. Hyperventilation

Explanation

Obstructive airway disease slows alveolar emptying and produces a sloping expiratory upstroke with an increased alpha angle. The plateau may also be prolonged as gas mixing is impaired.

Question 34Anesthesia Equipment, Monitoring, and Instrumentation

A bispectral index (BIS) value between 40 and 60 during general anesthesia generally indicates:

  1. An awake patient
  2. An inadequate depth of anesthesia
  3. Appropriate maintenance depth Correct answer.
  4. Burst suppression

Explanation

A BIS value of 40 to 60 is the usual target range for maintenance of general anesthesia. Higher values suggest lighter anesthesia, while very low values may indicate deep anesthesia or burst suppression.

Question 35Anesthesia Equipment, Monitoring, and Instrumentation

A sudden sustained increase in end-tidal carbon dioxide during controlled ventilation is most likely caused by:

  1. CO2 absorption during laparoscopy Correct answer.
  2. Hyperventilation
  3. Esophageal intubation
  4. A large circuit leak

Explanation

Insufflated carbon dioxide is absorbed into the circulation during laparoscopy and is excreted by the lungs, raising end-tidal carbon dioxide. Ventilation is usually increased to eliminate the additional carbon dioxide load.

Question 36Anesthesia Equipment, Monitoring, and Instrumentation

A small leak in the breathing circuit during positive-pressure ventilation would most likely cause:

  1. Failure to deliver the set tidal volume Correct answer.
  2. A sustained decrease in peak airway pressure
  3. A gradual rise in inspired carbon dioxide
  4. No measurable change in ventilation

Explanation

Gas escaping through a circuit leak reduces the volume delivered to the patient, so the set tidal volume cannot be maintained. Peak airway pressure and end-tidal carbon dioxide often fall as well.

Question 37Anesthesia Equipment, Monitoring, and Instrumentation

An arterial line waveform shows a narrow, overshooting systolic peak, and the systolic reading is higher than the cuff pressure. What does this indicate?

  1. An air bubble in the tubing
  2. A normally functioning system
  3. Underdamped measurement system Correct answer.
  4. Overdamped measurement system

Explanation

An underdamped system exaggerates the systolic peak and produces a narrow, ringing waveform with systolic overshoot. Stiff tubing and high natural frequency contribute to this artifact.

Question 38Anesthesia Equipment, Monitoring, and Instrumentation

The greatest risk of microshock occurs in a patient with:

  1. An intracardiac catheter in place Correct answer.
  2. Dry, intact skin
  3. Properly grounded external equipment
  4. Double-insulated monitoring devices

Explanation

An intracardiac catheter provides a low-resistance conductive pathway directly to the myocardium. Small currents that would be harmless at the skin surface can then trigger ventricular fibrillation.

Question 39Anesthesia Equipment, Monitoring, and Instrumentation

Which vaporizer uses a heated, pressurized reservoir because of the agent's low boiling point?

  1. Halothane variable-bypass vaporizer
  2. Sevoflurane variable-bypass vaporizer
  3. Enflurane variable-bypass vaporizer
  4. Desflurane vaporizer Correct answer.

Explanation

Desflurane has a boiling point near room temperature, so its vaporizer heats and pressurizes the agent to deliver a stable concentration. A conventional variable-bypass vaporizer would not control output reliably.

Question 40Anesthesia Equipment, Monitoring, and Instrumentation

Where should the oxygen analyzer be placed to best detect a hypoxic gas mixture delivered to the patient?

  1. On the ventilator exhaust port
  2. In the inspiratory limb of the circuit Correct answer.
  3. At the wall oxygen supply source
  4. In the expiratory limb of the circuit

Explanation

The oxygen analyzer should sample the inspiratory limb so that it measures the gas actually delivered to the patient. A low inspired oxygen alarm then warns of a hypoxic mixture before it reaches the airway.

Question 41Preoperative Evaluation and Coexisting Disease

Which finding is a component of the Revised Cardiac Risk Index (RCRI) for perioperative cardiac risk?

  1. Uncontrolled systemic hypertension
  2. Current tobacco smoking
  3. Age greater than 80 years
  4. History of cerebrovascular accident Correct answer.

Explanation

The RCRI includes high-risk surgery, ischemic heart disease, heart failure, cerebrovascular disease, insulin-dependent diabetes, and creatinine greater than 2.0 mg/dL. Age, hypertension, and smoking are general risk factors but are not RCRI components.

Question 42Preoperative Evaluation and Coexisting Disease

In a patient who smokes, how long before elective surgery should smoking cessation ideally begin to reduce pulmonary complications?

  1. At least 3 days before elective surgery
  2. At least 4 to 8 weeks before surgery Correct answer.
  3. At least 12 months before elective surgery
  4. At least 24 hours before elective surgery

Explanation

Abstinence for 4 to 8 weeks improves mucociliary clearance and reduces sputum production. Shorter periods may transiently increase secretions, while waiting a year is unnecessary for most elective operations.

Question 43Preoperative Evaluation and Coexisting Disease

A patient with type 2 diabetes takes glyburide daily. What is the most appropriate management on the morning of elective surgery?

  1. Double the dose to counter stress hyperglycemia
  2. Replace it with subcutaneous regular insulin at the same dose
  3. Give the usual dose with a light breakfast
  4. Withhold the dose and monitor glucose Correct answer.

Explanation

Sulfonylureas can cause hypoglycemia during the fasting period, so they are typically withheld on the day of surgery. Glucose should be monitored and hyperglycemia treated with insulin as needed.

Question 44Preoperative Evaluation and Coexisting Disease

Which variable is part of the STOP-BANG questionnaire for obstructive sleep apnea?

  1. Epworth Sleepiness Scale score above 10
  2. History of well-controlled asthma
  3. Serum bicarbonate level below 22 mEq/L
  4. BMI greater than 35 kg/m2 Correct answer.

Explanation

STOP-BANG stands for snoring, tiredness, observed apnea, pressure, BMI greater than 35, age greater than 50, neck circumference greater than 40 cm, and male gender. Asthma, Epworth score, and bicarbonate are not components.

Question 45Preoperative Evaluation and Coexisting Disease

How long before elective surgery should warfarin typically be discontinued to allow normalization of the INR in a patient with a mechanical heart valve?

  1. About 12 hours
  2. About 5 days Correct answer.
  3. About 24 hours
  4. About 14 days

Explanation

Warfarin has a half-life of roughly 40 hours, and stopping it about 5 days before surgery normalizes the INR in most patients. Shorter intervals leave residual anticoagulation, while longer intervals increase thromboembolic risk without benefit.

Question 46Preoperative Evaluation and Coexisting Disease

Which perioperative strategy best reduces bronchospasm in a patient with persistent asthma?

  1. Avoid regional anesthesia because it worsens bronchospasm
  2. Administer a single dose of oral prednisone only after extubation
  3. Stop inhaled corticosteroids 1 week before surgery
  4. Continue inhaled corticosteroids through the perioperative period Correct answer.

Explanation

Inhaled corticosteroids reduce airway inflammation and should be continued to prevent perioperative bronchospasm. Routine bronchodilators are also continued, and regional anesthesia is not contraindicated.

Question 47Preoperative Evaluation and Coexisting Disease

A patient had a non-ST-elevation myocardial infarction 10 weeks ago and is asymptomatic. He needs elective hernia repair. What is the most appropriate recommendation?

  1. Proceed now because he is asymptomatic
  2. Delay surgery for at least 6 months Correct answer.
  3. Proceed after a normal exercise stress test
  4. Proceed with spinal anesthesia instead of general anesthesia

Explanation

Elective surgery within 6 months of myocardial infarction is associated with a substantially increased risk of perioperative cardiac events, so surgery should generally be delayed. Asymptomatic status or a normal stress test does not eliminate that early risk.

Question 48Preoperative Evaluation and Coexisting Disease

A patient with a mechanical mitral valve takes warfarin and needs elective cholecystectomy. The INR is therapeutic. What is the best perioperative anticoagulation plan?

  1. Stop warfarin and give vitamin K to reverse immediately
  2. Stop warfarin and bridge with low-molecular-weight heparin Correct answer.
  3. Stop warfarin and start aspirin alone
  4. Continue warfarin and check INR on the day of surgery

Explanation

For a mechanical mitral valve, warfarin is stopped several days before surgery and bridged with low-molecular-weight heparin to reduce thromboembolic risk while limiting surgical bleeding. Aspirin alone is inadequate, and routine vitamin K reversal is unnecessary.

Question 49Preoperative Evaluation and Coexisting Disease

Which preoperative HbA1c value most reasonably warrants delaying elective surgery for further glycemic optimization?

  1. Greater than 5.7%
  2. Greater than 8% Correct answer.
  3. Any HbA1c above 5%
  4. Greater than 6.5%

Explanation

An HbA1c greater than 8% is commonly used as a threshold for preoperative optimization because poor glycemic control increases infection and wound complications. Prediabetic or mildly diabetic values do not usually justify delaying elective surgery.

Question 50Preoperative Evaluation and Coexisting Disease

Which finding is a component of the Child-Pugh classification for liver disease?

  1. Hepatic encephalopathy Correct answer.
  2. Platelet count
  3. Serum ammonia level
  4. Serum alkaline phosphatase

Explanation

The Child-Pugh score includes bilirubin, albumin, prothrombin time or INR, ascites, and hepatic encephalopathy. Alkaline phosphatase, platelet count, and ammonia are not scored variables.