skip to main content

Obesity hypoventilation overlap — RCPSC IM MCQ

Instant feedback + full explanation. One question, done properly.

ModerateRespirologyObesity hypoventilation overlapRCPSC IM

A 73-year-old man with COPD reports morning headaches and daytime somnolence. BMI is 41 kg/m2. Oxygen saturation is 91 percent awake, serum bicarbonate is 34 mmol/L, and spirometry shows moderate obstruction. What is the most appropriate investigation?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: A — D-dimer

Obesity, hypersomnolence, elevated bicarbonate, and COPD raise concern for chronic hypercapnia and sleep-disordered breathing. ABG and sleep testing assess obesity hypoventilation and overlap syndrome.

Reference: Canadian Thoracic Society sleep-disordered breathing guidance