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Carbon monoxide poisoning with cardiac ischaemia — SCE Acute Medicine MCQ

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HardClinical pharmacology and poisoningCarbon monoxide poisoning with cardiac ischaemiaSCE Acute Medicine

A family of four presents with headache, nausea and dizziness after using a faulty boiler. One adult is confused; pulse oximetry reads 99% on air and ABG co-oximetry shows carboxyhaemoglobin 28%. ECG shows lateral ST depression. What is the most appropriate next step in management?

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Correct answer: C — Give high-flow oxygen and discuss hyperbaric oxygen because of neurological and cardiac features

Carbon monoxide poisoning can show falsely normal pulse oximetry because standard oximeters cannot distinguish oxyhaemoglobin from carboxyhaemoglobin. Neurological impairment, high carboxyhaemoglobin and ECG ischaemia support high-flow oxygen and discussion about hyperbaric therapy. Methylene blue treats methaemoglobinaemia, not carbon monoxide poisoning.

Reference: TOXBASE carbon monoxide poisoning; UKHSA carbon monoxide guidance