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Carbon monoxide poisoning — ACEM Fellowship MCQ

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HardToxicologyCarbon monoxide poisoningACEM Fellowship

A family develops headache, nausea and confusion after using a petrol generator indoors; one adult briefly collapsed. Pulse oximetry reads 99% on room air. What should be done immediately?

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

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Correct answer: DGive high-concentration oxygen and obtain blood co-oximetry

The best answer is “Give high-concentration oxygen and obtain blood co-oximetry”. Conventional pulse oximetry cannot distinguish carboxyhaemoglobin from oxyhaemoglobin and may appear normal in severe poisoning. High-concentration oxygen is started immediately and co-oximetry measures carboxyhaemoglobin; collapse, neurological features, pregnancy and other severity factors prompt specialist discussion about hyperbaric treatment. Skin colour and PaO2 cannot safely exclude the diagnosis.

Reference: NSW Agency for Clinical Innovation: Burn patient management clinical practice guide: https://aci.health.nsw.gov.au/__data/assets/pdf_file/0009/250020/ACI-Burn-Patient-Management-Clinical-Practice-Guide.pdf