Indications for platelet transfusion
a. bone marrow failure (hematological malignancy, post-chemotherapy, aplastic anemia);
b. disseminated intravascular coagulation (DIC);
c. massive transfusion;
d. immune thrombocytopenia (only in severe bleeding).
2. Platelet dysfunction:
a. congenital (rare);
b. acquired (cardiopulmonary bypass surgery, drug induced (aspirin), uremia).
Platelet transfusions are contraindicated in thrombotic thrombocytopenic purpura, hemolytic uremic syndrome, and heparin-induced thrombocytopenia because the underlying tendency is for thrombosis rather than bleeding.