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Severe lithium toxicity — RCPSC EM MCQ

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HardToxicologySevere lithium toxicityRCPSC EM

A 29-year-old presents after a large aspirin ingestion with tinnitus, tachypnoea, confusion, pH 7.47, PaCO2 18 mmHg and bicarbonate 13 mmol/L. What is the appropriate immediate toxicology plan?

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Correct answer: E — Start bicarbonate alkalinisation and arrange dialysis assessment

The best answer is “Start bicarbonate alkalinisation and arrange dialysis assessment”. This mixed respiratory alkalosis and metabolic acidosis is significant salicylate toxicity. Bicarbonate alkalinisation promotes renal elimination and should be started with serial levels and early dialysis assessment. Intubation can rapidly worsen acidaemia if minute ventilation is not maintained, so it is avoided unless unavoidable and then managed with expert planning.

Reference: Ontario Poison Centre: Salicylates protocol: https://www.ontariopoisoncentre.ca/siteassets/pdfs/english/protocols/salicylates_4-pages.pdf