American Board of Internal Medicine (ABIM) Certification Practice Exam

In clinically stable patients with chemotherapy-induced thrombocytopenia, platelet transfusion is unnecessary when the platelet count is:

1. Below 5,000/µL

2. 10,000/µL or greater

3. Below 15,000/µL

4. Below 20,000/µL

The correct answer is: 10,000/µL or greater

In clinically stable patients experiencing chemotherapy-induced thrombocytopenia, platelet transfusion is typically deemed unnecessary when the platelet count is 10,000/µL or greater. This threshold is grounded in the understanding that patients with platelet counts at or above this level generally have a low risk of bleeding. Research indicates that while the risk of bleeding increases as platelet counts drop, many patients with counts above 10,000/µL can maintain hemostasis without the need for transfusions, especially if they are not exhibiting other bleeding risks and are clinically stable. The focus on minimizing unnecessary transfusions is important, as platelet transfusions can carry risks such as allergic reactions, febrile non-hemolytic reactions, and transfusion-related acute lung injury, as well as increased healthcare costs and utilization of blood products. In contrast, lower platelet thresholds, such as 5,000/µL or 15,000/µL, suggest situations where transfusion may be more readily considered due to the heightened risk of bleeding associated with such counts. Similarly, using a threshold of 20,000/µL would include a broader range of patients where transfusions might not be required, but again, clinical stability and individual patient factors are critical