COPD USMLE Step 1 Practice Question
A 65-year-old man with a 40-pack-year smoking history and known emphysematous changes on prior imaging presents to the emergency department with acute-onset pleuritic chest pain and dyspnea that developed while watching television. He reports no recent illness or leg swelling. Vital signs: BP 138/85 mmHg, HR 112 bpm, RR 28/min, O2 saturation 88% on room air. Physical examination reveals decreased breath sounds and hyperresonance to percussion on the right hemithorax, with normal vocal fremitus. Trachea is midline. Chest X-ray demonstrates a right-sided visceral pleural line separated from the chest wall with absent lung markings peripherally. Which of the following best explains the mechanism of this patient's acute decompensation?
Answer choices
- ARupture of a subpleural emphysematous bleb with air leak into the pleural spaceCorrect answer
- BAcute bacterial infection with formation of a loculated parapneumonic effusion
- CPulmonary embolism with acute right ventricular strain and cor pulmonale
- DSpontaneous hemothorax from erosion of an intercostal artery by emphysematous changes
- EAcute exacerbation of COPD with right mainstem bronchus mucus impaction and atelectasis
- FTension pneumomediastinum from barotrauma during forced expiration
See the full explanation
Get the correct-answer rationale, why each distractor is wrong, the underlying mechanism, and high-yield associations — plus adaptive practice that targets your weak areas — with a free MedBoardPRO account.