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Smoke inhalation with carbon monoxide and cyanide toxicity — RCPSC EM MCQ

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HardRespiratory emergenciesSmoke inhalation with carbon monoxide and cyanide toxicityRCPSC EM

A family is rescued from a house fire. A 34-year-old woman is confused and vomiting with soot around the mouth; carboxyhaemoglobin is 28%, lactate is 10 mmol/L, and oxygen saturation by pulse oximetry reads 99%. What is the most likely diagnosis?

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Correct answer: D — Smoke inhalation with carbon monoxide and cyanide toxicity

CO poisoning makes pulse oximetry unreliable, and severe lactic acidosis after smoke exposure suggests cyanide toxicity as well as CO exposure.

Reference: Canadian toxicology practice; burn centre guidance