Blood transfusions in cardiac surgery: indications, risks, and conservation strategies.

Although red blood cell (RBC) transfusions are frequently used in cardiac operations, an increasing amount of data has demonstrated deleterious consequences. Consequently, the appropriate use of this limited resource is unclear. In this review, we discuss the relationship between anemia and the outcomes of cardiac surgical procedures, the risks associated with RBC transfusion, and the impact of blood transfusions on mortality and morbidity after cardiac operations. The review concludes with a discussion of randomized trials comparing restrictive versus liberal transfusion strategies and a consideration of blood conservation techniques.