Blood transfusion: uses, abuses, and hazards.

Homologous blood transfusion without risk is an unobtainable goal. Infection with human immunodeficiency virus continues to occur at an average rate of one infection per 100,000 transfusions, in spite of the most sensitive and specific testing available. In the past 30 years, the number of red cell antigens identified have increased from primarily ABO and Rh to some 400 antigens, which has also contributed to the hazards of blood transfusion. These risks can be minimized by the judicious use of homologous blood in conjunction with technological advances in transfusion medicine therapy and changes in attitudes of transfusionists. In the operating theater, there has been a resurgence in intraoperative autologous transfusion therapy, and patients are individualized rather than held to an arbitrary hemoglobin standard prior to anesthesia. In the preoperative period, elective surgical candidates may predeposit autologous blood or select directed donors. The prospective recipient or the directed donor may be candidate for recombinant erythropoietin therapy as a prelude to blood donation. This article discusses the uses of blood and blood products, the hazards of blood transfusion, and precautions that can be taken to minimize risks to the patient.