COMSAE Phase 2 – Clinical Science
Practice Exam Questions with Verified
Answers & Detailed Rationales
Question 1 — Cardiology
A 68-year-old man with a history of hypertension and
hyperlipidaemia presents with 90 minutes of crushing
substernal chest pain radiating to the left arm. ECG
demonstrates ST-segment elevations in leads II, III, and aVF.
Blood pressure is 88/54 mmHg, jugular venous pressure is
elevated, and lung examination is clear. Which of the
following is the most likely complication associated with this
patient's infarction?
A. Acute papillary muscle rupture
B. Ventricular septal rupture
C. Right ventricular infarction
D. Left ventricular free-wall rupture
Rationale: Inferior STEMI with hypotension, elevated JVP, and
clear lungs strongly suggests right ventricular infarction,
usually due to proximal right coronary artery occlusion. Right
ventricular failure decreases left ventricular preload,
producing hypotension without pulmonary oedema.
Management includes cautious volume expansion and
avoidance of nitrates or excessive diuresis, which can further
reduce preload.
,Question 2 — Neurology
A 72-year-old woman develops sudden right-sided weakness
and aphasia. She has atrial fibrillation but is not taking
anticoagulation. CT of the head shows no haemorrhage. MRI
demonstrates an acute infarction involving the left middle
cerebral artery territory. Which vascular structure is most
likely occluded?
A. Left anterior cerebral artery
B. Left middle cerebral artery
C. Left posterior cerebral artery
D. Basilar artery
Rationale: The middle cerebral artery supplies the lateral
frontal, parietal, and temporal lobes. Dominant-hemisphere
involvement produces aphasia, while contralateral face and
upper-extremity weakness are typically more prominent than
lower-extremity weakness. Atrial fibrillation strongly suggests
an embolic ischemic stroke.
Question 3 — Endocrinology
A 24-year-old woman presents with vomiting, abdominal
pain, hypotension, and diffuse hyperpigmentation.
Laboratory studies show sodium 124 mmol/L, potassium 6.1
mmol/L, glucose 3.0 mmol/L, and low serum cortisol. Which
of the following is the most appropriate immediate
treatment?
,A. Oral fludrocortisone alone
B. Insulin infusion without fluids
C. Intravenous hydrocortisone and isotonic saline
D. Intravenous levothyroxine alone
Rationale: This presentation is consistent with acute adrenal
crisis due to primary adrenal insufficiency. Treatment should
begin immediately with intravenous hydrocortisone and
aggressive isotonic fluid replacement. Hypoglycaemia should
also be corrected when present. Hyperkalaemia occurs
because aldosterone deficiency reduces renal potassium
excretion.
Question 4 — Infectious Disease
A 35-year-old man presents with fever, headache, neck
stiffness, and photophobia. Lumbar puncture reveals
elevated opening pressure, neutrophilic pleocytosis, high
protein, and low glucose. Gram stain demonstrates gram-
negative diplococci. Which organism is most likely
responsible?
A. Streptococcus pneumoniae
B. Neisseria meningitidis
C. Haemophilus influenzae type b
D. Listeria monocytogenes
Rationale: Neisseria meningitidis is a gram-negative, kidney-
shaped diplococcus that causes acute bacterial meningitis,
particularly in adolescents and young adults. It may also
cause meningococcaemia with petechial or purpuric rash.
, Close contacts require chemoprophylaxis.
Question 5 — Pulmonology
A 64-year-old man with severe COPD presents with
worsening dyspnoea. Arterial blood gas analysis shows pH
7.25, PaCO₂ 72 mmHg, and HCO₃⁻ 31 mmol/L. Which acid-
base disorder best explains these findings?
A. Acute respiratory alkalosis
B. Metabolic acidosis
C. Acute-on-chronic respiratory acidosis
D. Chronic metabolic alkalosis
Rationale: The elevated PaCO₂ indicates respiratory acidosis.
The elevated bicarbonate indicates chronic renal
compensation, while the markedly decreased pH suggests an
acute worsening superimposed on chronic CO₂ retention. This
pattern is typical of acute-on-chronic hypercapnic respiratory
failure in severe COPD.
Difficulty: Hard
Question 6 — Gastroenterology
A 55-year-old man with a history of alcohol use disorder
presents with massive haematemesis. He is hypotensive and
tachycardic. After initial resuscitation, which medication
should be administered to reduce portal venous pressure
while urgent endoscopy is arranged?
Practice Exam Questions with Verified
Answers & Detailed Rationales
Question 1 — Cardiology
A 68-year-old man with a history of hypertension and
hyperlipidaemia presents with 90 minutes of crushing
substernal chest pain radiating to the left arm. ECG
demonstrates ST-segment elevations in leads II, III, and aVF.
Blood pressure is 88/54 mmHg, jugular venous pressure is
elevated, and lung examination is clear. Which of the
following is the most likely complication associated with this
patient's infarction?
A. Acute papillary muscle rupture
B. Ventricular septal rupture
C. Right ventricular infarction
D. Left ventricular free-wall rupture
Rationale: Inferior STEMI with hypotension, elevated JVP, and
clear lungs strongly suggests right ventricular infarction,
usually due to proximal right coronary artery occlusion. Right
ventricular failure decreases left ventricular preload,
producing hypotension without pulmonary oedema.
Management includes cautious volume expansion and
avoidance of nitrates or excessive diuresis, which can further
reduce preload.
,Question 2 — Neurology
A 72-year-old woman develops sudden right-sided weakness
and aphasia. She has atrial fibrillation but is not taking
anticoagulation. CT of the head shows no haemorrhage. MRI
demonstrates an acute infarction involving the left middle
cerebral artery territory. Which vascular structure is most
likely occluded?
A. Left anterior cerebral artery
B. Left middle cerebral artery
C. Left posterior cerebral artery
D. Basilar artery
Rationale: The middle cerebral artery supplies the lateral
frontal, parietal, and temporal lobes. Dominant-hemisphere
involvement produces aphasia, while contralateral face and
upper-extremity weakness are typically more prominent than
lower-extremity weakness. Atrial fibrillation strongly suggests
an embolic ischemic stroke.
Question 3 — Endocrinology
A 24-year-old woman presents with vomiting, abdominal
pain, hypotension, and diffuse hyperpigmentation.
Laboratory studies show sodium 124 mmol/L, potassium 6.1
mmol/L, glucose 3.0 mmol/L, and low serum cortisol. Which
of the following is the most appropriate immediate
treatment?
,A. Oral fludrocortisone alone
B. Insulin infusion without fluids
C. Intravenous hydrocortisone and isotonic saline
D. Intravenous levothyroxine alone
Rationale: This presentation is consistent with acute adrenal
crisis due to primary adrenal insufficiency. Treatment should
begin immediately with intravenous hydrocortisone and
aggressive isotonic fluid replacement. Hypoglycaemia should
also be corrected when present. Hyperkalaemia occurs
because aldosterone deficiency reduces renal potassium
excretion.
Question 4 — Infectious Disease
A 35-year-old man presents with fever, headache, neck
stiffness, and photophobia. Lumbar puncture reveals
elevated opening pressure, neutrophilic pleocytosis, high
protein, and low glucose. Gram stain demonstrates gram-
negative diplococci. Which organism is most likely
responsible?
A. Streptococcus pneumoniae
B. Neisseria meningitidis
C. Haemophilus influenzae type b
D. Listeria monocytogenes
Rationale: Neisseria meningitidis is a gram-negative, kidney-
shaped diplococcus that causes acute bacterial meningitis,
particularly in adolescents and young adults. It may also
cause meningococcaemia with petechial or purpuric rash.
, Close contacts require chemoprophylaxis.
Question 5 — Pulmonology
A 64-year-old man with severe COPD presents with
worsening dyspnoea. Arterial blood gas analysis shows pH
7.25, PaCO₂ 72 mmHg, and HCO₃⁻ 31 mmol/L. Which acid-
base disorder best explains these findings?
A. Acute respiratory alkalosis
B. Metabolic acidosis
C. Acute-on-chronic respiratory acidosis
D. Chronic metabolic alkalosis
Rationale: The elevated PaCO₂ indicates respiratory acidosis.
The elevated bicarbonate indicates chronic renal
compensation, while the markedly decreased pH suggests an
acute worsening superimposed on chronic CO₂ retention. This
pattern is typical of acute-on-chronic hypercapnic respiratory
failure in severe COPD.
Difficulty: Hard
Question 6 — Gastroenterology
A 55-year-old man with a history of alcohol use disorder
presents with massive haematemesis. He is hypotensive and
tachycardic. After initial resuscitation, which medication
should be administered to reduce portal venous pressure
while urgent endoscopy is arranged?
