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MH Susceptible Anaesthetic Technique — FRCA Final MCQ

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ModerateGeneral AnaesthesiaMH Susceptible Anaesthetic TechniqueFRCA Final

A 30-year-old woman (60 kg) with known susceptibility to malignant hyperthermia (positive in vitro contracture test) requires anaesthesia for appendicectomy. What is the safe anaesthetic technique?

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

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Correct answer: B — Any technique using a new CO2 absorber

MH-susceptible patients must receive a 'trigger-free' anaesthetic: no volatile agents (sevoflurane, desflurane, isoflurane) and no suxamethonium. TIVA with propofol and remifentanil (or other opioids) is the standard approach. The anaesthetic machine must be prepared: remove or disable vaporisers, flush the circuit with high-flow O2 (10 L/min) for ≥20 minutes (or use a new circuit), replace CO2 absorber, and use a new breathing circuit. N2O is NOT a trigger and is safe. All non-depolarising muscle relaxants are safe. Dantrolene must be immediately available.

Reference: EMHG – 2021 – Perioperative management of MH susceptible patients; AAGBI – 2020 – MH guidelines