The scope of the problem

Despite refinements in cardiac surgical technique, disorders of haemostasis remain a significant problem, reflecting the effects of cardiopulmonary bypass on blood cell activation and coagulation. Increased understanding of the dangers of blood and blood product transfusion have shifted the goals from blood replacement to blood conservation in cardiac surgery. Two approaches to blood conservation are used: autotransfusion and administration of pharmacological agents. These approaches may be complementary, but the latter approach- preventing or at least modifying the haemostatic disorder- may be preferable. This paper reviews some of the pharmacological agents that have been used in an attempt to conserve blood, including e-aminocaproic acid, desmopressin, prostacyclin, tranexamic acid, dipyridamole, and aprotinin. None of these agents has been able to eliminate the need for blood transfusion in all patients; aprotinin has been successful, however, in eliminating the need for transfusion in some patients and dramatically reducing the need in others.