Pulmonary Embolism USMLE Step 1 Practice Question
A 68-year-old woman is admitted to the hospital following surgical repair of an intertrochanteric hip fracture. On postoperative day 3, she develops acute onset dyspnea and sharp, pleuritic chest pain that worsens with deep inspiration. Her vital signs are: heart rate 118 bpm, blood pressure 132/78 mmHg, respiratory rate 22/min, oxygen saturation 88% on room air, and temperature 37.2°C. Physical examination reveals unilateral lower extremity edema and calf tenderness on the affected side. Chest X-ray is unremarkable without infiltrates or effusions. Electrocardiogram shows sinus tachycardia without acute ischemic changes. A D-dimer level is elevated at 2.5 μg/mL (normal <0.5). Which of the following is the most appropriate next diagnostic step?
Answer choices
- AComputed tomography pulmonary angiography (CTPA) of the chest with IV contrastCorrect answer
- BCompression ultrasonography of both lower extremities
- CVentilation-perfusion (V/Q) scan
- DTransthoracic echocardiography to assess right ventricular function
- ERepeat D-dimer and observe for clinical deterioration
- FInitiate therapeutic anticoagulation with unfractionated heparin pending imaging studies
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