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Carbon monoxide poisoning — RCPSC EM MCQ

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HardToxicologyCarbon monoxide poisoningRCPSC EM

CTAS 2. A 31-year-old is rescued from a garage with headache, vomiting, and confusion. SpO2 reads 100% on pulse oximetry, lactate is 4.8 mmol/L, and ECG shows sinus tachycardia. His partner has similar symptoms. What is the most appropriate investigation?

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Correct answer: B — Co-oximetry carboxyhaemoglobin level

Pulse oximetry is misleading in carbon monoxide poisoning; diagnosis is supported by co-oximetry carboxyhaemoglobin level and exposure history.

Reference: Health Canada carbon monoxide guidance; Ontario Poison Centre