Pulmonary Embolism USMLE Step 1 Practice Question
A 58-year-old man with a 2-week history of pancreatic cancer presents to the emergency department with acute onset dyspnea. He reports that 3 days ago he underwent a percutaneous biliary stent placement and has been immobilized since discharge. Vital signs: BP 132/78 mmHg, HR 94 bpm, RR 22/min, SpO2 96% on room air, temperature 36.9°C. Physical examination reveals unilateral left leg swelling and calf tenderness. Comprehensive metabolic panel is unremarkable. Troponin I is 0.02 ng/mL (normal <0.04). BNP is mildly elevated at 180 pg/mL. D-dimer is 3.2 mcg/mL. CT pulmonary angiography shows bilateral subsegmental pulmonary emboli with normal right ventricular diameter and no pericardial effusion. Hemodynamics are stable with no evidence of shock. The patient has never received anticoagulation. Which of the following is the most appropriate initial management?
Answer choices
- ATherapeutic anticoagulation with low-molecular-weight heparin or unfractionated heparinCorrect answer
- BObservation with serial D-dimer measurements and repeat imaging in 24 hours
- CPlacement of a retrievable inferior vena cava filter without anticoagulation
- DSystemic thrombolytic therapy followed by anticoagulation
- EAnticoagulation only if symptoms progress or right ventricular dilatation develops
- FSupportive care with supplemental oxygen and early mobilization without anticoagulation
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.