Pulmonary Embolism USMLE Step 1 Practice Question
A 45-year-old woman presents with acute onset dyspnea and pleuritic chest pain 3 days after total knee arthroplasty. Vital signs show tachycardia (110 bpm) and tachypnea (24/min). Arterial blood gas reveals pH 7.48, PaCO2 28 mmHg, PaO2 72 mmHg. Chest X-ray is normal. Which of the following is the most likely diagnosis?
Answer choices
- AAspiration pneumonia
- BSpontaneous pneumothorax
- CAcute asthma exacerbation
- DAcute myocardial infarction
- EPulmonary embolismCorrect answer
- FAcute pericarditis with pericardial effusion
See the full explanation
Get the correct-answer rationale, why each distractor is wrong, the underlying mechanism, and high-yield associations ā plus adaptive practice that targets your weak areas ā with a free MedBoardPRO account.