Pulmonary Embolism USMLE Step 1 Practice Question
A 72-year-old woman with advanced emphysema is found unresponsive at home. Vital signs: BP 88/54, HR 118, RR 28, SpO2 75% on room air. Arterial blood gas reveals pH 7.20, pCO2 78, pO2 45. Chest X-ray shows hyperinflation without acute infiltrate or pneumothorax. She denies recent leg swelling or chest pain. Current medications include albuterol inhaler only. Which of the following is the most appropriate immediate intervention?
Answer choices
- AComputed tomography pulmonary angiography
- BImmediate intubation and mechanical ventilation
- CHigh-flow oxygen to target SaO2 >94%
- DNoninvasive positive pressure ventilationCorrect answer
- EBronchodilators and corticosteroids only
- FAdminister controlled low-flow oxygen via Venturi mask titrated to SpO2 88-92%
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