Transfusion Medicine.

Transfusion of various blood components can provide relief from symptomatic anemia and reduce the bleeding risks associated with low platelet counts or presence of coagulopathy. Blood components are collected from volunteer donors and processed into separate components to maximize efficient utilization of a scarce resource while also providing maximum clinical benefit. Tests including blood type and screening for clinically significant alloantibodies increase the likelihood of successful transfusion. Risks of transfusion include hypersensitivity and hemolytic transfusion reactions, transfusion-related acute lung injury, transfusion-associated circulatory overload, and transmission of infection. Indications for transfusion are reviewed along with various products available for transfusion.