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MH Earliest Sign ETCO2 Rise — FRCA Primary MCQ

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ModeratePharmacology - General PrinciplesMH Earliest Sign ETCO2 RiseFRCA Primary

Regarding malignant hyperthermia (MH) the earliest clinical sign is often:

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Correct answer: B — Unexplained rise in end-tidal CO2 and tachycardia

The earliest signs of MH are typically: unexplained rise in ETCO2 (despite adequate ventilation) and tachycardia. Temperature rise is often a LATER sign. Other signs: muscle rigidity (especially masseter after suxamethonium) / tachyarrhythmias / metabolic acidosis / hyperkalaemia / myoglobinuria / and elevated CK. Treatment: stop trigger / dantrolene 2.5 mg/kg / active cooling / treat hyperkalaemia.

Reference: Peck Hill Williams 2014 Pharmacology for Anaesthesia and Intensive Care