Risks of blood transfusion and their prevention.

As a result of significant progress in reducing the risks of transfusion-transmitted viral infections, bacterial contamination of platelet components (1:2,000) and sepsis (1:50,000) are now the most frequent infectious complications of blood transfusions. Sepsis from bacterial contamination of red cell components is less frequent (1:500,000), because red blood cells, unlike platelet components, can be stored at refrigerated temperatures (1 degrees C-4 degrees C). Current risks for transfusion-transmitted viral diseases (per blood component transfused) are: human immunodeficiency virus, 1:2,135,000; hepatitis C virus, 1:1,935,000; hepatitis B virus, 1:205,000; and human T-lymphotropic viruses, 1:2,993,000. Transfusion-transmitted babesiosis has increased morbidity and mortality for splenectomized patients. Immunocompromised recipients are at increased risk of developing Chagas disease from blood contaminated by Trypanosoma cruzi. Reports of transfusion-related acute lunge injury and transfusion-associated graft-versus-host disease increase each year as physicians become increasingly aware of their varied clinical presentations. While strategies for preventing infections complications focus primarily on blood donor services, individual physicians can reduce risks to their patients by maintaining conservative "triggers" for transfusions, prescribing pharmacologic agents to reduce bleeding (antifibrinolytic drugs, serine protease inhibitors, fibrin sealants), and using epoetin alpha to reduce transfusion of red cells in selected patients.