Pulmonary Embolism USMLE Step 1 Practice Question
A 56-year-old man with acute PE (CT pulmonary angiography positive for right lower lobe segmental thrombus) is started on therapeutic enoxaparin. Vitals: BP 128/82, HR 102, RR 18, SpO2 98% on room air. Three days later, platelet count drops from 210,000 to 85,000/mm³ with no clinical bleeding or petechiae. He takes no antiplatelet agents. Which of the following is the most appropriate next step?
Answer choices
- ATransfuse platelets to maintain count above 100,000
- BSwitch to warfarin immediately
- CStop all anticoagulation and observe
- DOrder a serotonin release assay and switch to argatrobanCorrect answer
- EContinue enoxaparin because the platelet count is above 50,000
- FAdminister intravenous immunoglobulin and continue enoxaparin with close monitoring
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.