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Myasthenic crisis — RCPSC EM MCQ

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HardNeurological emergenciesMyasthenic crisisRCPSC EM

CTAS 1. A 61-year-old with known myasthenia gravis has dyspnoea after pneumonia. She has ptosis, weak cough, and cannot count past 8 on one breath. FVC is 12 mL/kg and NIF is -18 cmH2O. ABG shows rising PaCO2. What is the most likely diagnosis?

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Correct answer: E — Myasthenic crisis

Bulbar weakness, poor respiratory mechanics, infection trigger, and hypercapnia in known myasthenia indicate myasthenic crisis.

Reference: Canadian Neurological Sciences Federation resources; Tintinalli's Emergency Medicine