Pulmonary Embolism USMLE Step 1 Practice Question
A 70-year-old man with a history of hypertension and stage 3b chronic kidney disease (eGFR 28 mL/min/1.73m²) presents to the emergency department with acute dyspnea and pleuritic chest pain that began 6 hours ago. He denies recent surgery, immobilization, or lower extremity swelling. Vital signs are: blood pressure 138/82 mmHg, heart rate 102 bpm, respiratory rate 22/min, SpO2 92% on room air, and temperature 37.2°C. Physical examination reveals clear lung fields and no signs of deep vein thrombosis. Laboratory studies show troponin I 0.02 ng/mL (normal <0.04), D-dimer 3.5 mcg/mL (elevated), and BNP 250 pg/mL (normal <100). Computed tomography pulmonary angiography (CTPA) demonstrates no pulmonary embolism but incidentally reveals a small 5-mm pericardial effusion without echocardiographic evidence of tamponade physiology, pulsus paradoxus, or hemodynamic instability. Which of the following is the most appropriate next step in management?
Answer choices
- AInitiate therapeutic anticoagulation with low-molecular-weight heparin and transition to warfarin based on the elevated D-dimer and pleuritic chest pain
- BObtain transthoracic echocardiography to characterize the pericardial effusion, assess cardiac function, and exclude alternative diagnosesCorrect answer
- CDischarge the patient home with outpatient cardiology follow-up and reassurance that the pericardial effusion is clinically insignificant
- DPerform urgent pericardiocentesis with fluid analysis given the presence of pleuritic symptoms and elevated D-dimer
- EPlace an inferior vena cava (IVC) filter to prevent paradoxical embolism through a potential patent foramen ovale
- FRepeat CTPA with higher resolution imaging within 24 hours to exclude submassive pulmonary embolism
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