Complications of blood transfusion. How to recognize and respond to noninfectious reactions.

Severe transfusion reactions occur much less often than minor reactions, but it is difficult to discriminate clinically between impending severe reactions and minor reactions. Therefore, whenever a reaction occurs, the transfusion should be discontinued and a laboratory workup initiated to rule out an acute hemolytic transfusion reaction. At a minimum, a direct antiglobulin (Coombs') test should be performed, and specimens obtained before and after transfusion should be assayed for hemoglobinemia and hemoglobinuria. If the product transfused included red blood cells, then typing and crossmatching should be repeated on a posttransfusion blood specimen. Routine premedication with antipyretics is not recommended, since they may mask early signs and symptoms of more severe reactions and their efficacy is questionable. Recent insights into the mechanisms of transfusion reactions have suggested interventions that may help minimize or prevent potentially serious sequelae.