American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the platelet transfusion threshold during active bleeding?

1. 20K

2. 10K

3. 50K

4. 100K

The correct answer is: 50K

In the context of active bleeding, the platelet transfusion threshold is set at a level to ensure adequate hemostasis, thereby preventing significant bleeding complications. A threshold of 50,000 platelets per microliter is typically recommended for patients who are actively bleeding, particularly if they are undergoing invasive procedures or have a clinical condition that predisposes them to extensive hemorrhage. This approach is based on clinical guidelines and evidence suggesting that maintaining platelet counts above this threshold reduces the risk of bleeding. Only when the platelet count rises above this level can the physiological needs of the body during active bleeding be reasonably met, enhancing the efficacy of the transfusion in managing acute bleeding events. Lower thresholds, such as 10,000 or 20,000, may be applied under different clinical conditions, such as prophylactic settings in patients without active bleeding or for certain patients with specific risk factors. A higher threshold like 100,000 may be more conservative, often not necessary in cases of active bleeding unless there are additional complications or comorbidities. Thus, for active bleeding scenarios, maintaining a threshold of 50,000 platelets for transfusion is appropriate and considered best practice.