Neuromuscular Disorders USMLE Step 1 Practice Question
A 57-year-old man with progressive neuromuscular weakness presents with morning headaches and orthopnea. Vital signs show BP 145/92, HR 88, RR 22, temperature 37.2°C, SpO2 98% on room air. Pulmonary examination is clear to auscultation bilaterally. Arterial blood gas reveals pH 7.32, PCO2 58 mmHg, HCO3 28 mEq/L. He denies recent infections. Which of the following muscles is most important to evaluate for impending ventilatory failure?
Answer choices
- ABiceps brachii
- BDeltoid
- CDiaphragmCorrect answer
- DMasseter
- ETemporalis
- FExternal intercostal muscles
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