Which laboratory finding is expected after treatment with aspirin?

Which laboratory finding is expected after treatment with aspirin?

• A. Prothrombin time prolonged
• B. Partial thromboplastin time prolonged
• C. Bleeding time prolonged
• D. Platelet count decreased

Answer: (C)

Aspirin blocks platelet function by irreversibly inhibiting cyclooxygenase-1, which reduces thromboxane A2 production and impairs platelet aggregation. Because primary hemostasis relies on platelets forming a plug, this impairment lengthens the time it takes to stop a small bleed, so bleeding time is prolonged. Coagulation tests like prothrombin time and partial thromboplastin time assess the clotting cascade in plasma, not platelet function, so they stay normal. Platelet count also remains unchanged since aspirin affects how platelets work, not how many there are. So the expected lab finding after aspirin treatment is a prolonged bleeding time.

Aspirin blocks platelet function by irreversibly inhibiting cyclooxygenase-1, which reduces thromboxane A2 production and impairs platelet aggregation. Because primary hemostasis relies on platelets forming a plug, this impairment lengthens the time it takes to stop a small bleed, so bleeding time is prolonged. Coagulation tests like prothrombin time and partial thromboplastin time assess the clotting cascade in plasma, not platelet function, so they stay normal. Platelet count also remains unchanged since aspirin affects how platelets work, not how many there are. So the expected lab finding after aspirin treatment is a prolonged bleeding time.