Which of the following is a risk factor for pulmonary embolism related to stroke history?

• A. Hip or total knee implant
• B. History of stroke
• C. Obesity
• D. Acute respiratory infection

Answer: (B)

The main idea is that a history of stroke increases the risk of pulmonary embolism mainly because stroke often leads to reduced mobility, which promotes venous stasis and deep vein thrombosis. When movement is limited, blood in the leg veins doesn’t flow as well, making clots more likely to form. If a clot from the legs breaks off, it can travel to the lungs and cause a pulmonary embolism. So prior stroke is a direct indicator of higher PE risk due to these immobility- and clotting-related processes. The other options describe risks that aren’t specifically tied to a history of stroke: a hip or knee implant is more about surgery and postoperative immobility, obesity is a general PE risk not unique to stroke history, and an acute respiratory infection isn’t a primary driver of PE through prior stroke. In practice, preventing PE after stroke focuses on early mobilization and measures to reduce DVT risk.