American Board of Internal Medicine (ABIM) Certification Practice Exam

What level of platelet count indicates that transfusion would not benefit patients with chemotherapy-induced thrombocytopenia?

1. Less than 5,000/µL

2. 10,000/µL or greater

3. 15,000/µL or greater

4. Below 20,000/µL

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

In the context of chemotherapy-induced thrombocytopenia, transfusions are typically most beneficial for patients experiencing severe bleeding or for those whose platelet counts are critically low. A platelet count of 10,000/µL or greater signifies a level where the risk of spontaneous bleeding is significantly lower compared to counts below this threshold. At this level, while the patient may still be thrombocytopenic, the body may be able to manage without intervention through transfusion. It is generally established that transfusions are unlikely to be beneficial when the platelet count is in this range, as patients are at less risk for bleeding complications, and the adverse effects of transfusion may outweigh the potential benefits. Counts below 10,000/µL are associated with a higher risk of significant bleeding, making transfusion more likely to be indicated at those lower levels. Therefore, the key understanding is that a platelet count of 10,000/µL illustrates a threshold above which transfusion is often not necessary.