Modifying perioperative blood loss.

Fears about the risks of disease transmission through the transfusion of homologous blood, as well as problems with blood supply and cost have increased the interest in reducing perioperative bleeding. This article discusses the causes of non-surgical perioperative bleeding and attempts to reduce perioperative bleeding with pharmacological agents. There is particular emphasis on the effects of cardiopulmonary bypass on haemostasis as the majority of studies have been conducted in this area. The agents discussed include the use of fibrin sealants, antiplatelet agents such as dipyridamole and prostacyclin analogues, antifibrinolytics and the effects of desmopressin and aprotinin. Currently high dose aprotinin would appear to be the most efficacious method of reducing perioperative bleeding in cardiac surgery, although a full risk benefit analysis is not yet possible. The effectiveness of aprotinin and tranexamic acid in reducing the 'oozing' seen in any surgical patient suggests the contribution of fibrinolysis in causing perioperative bleeding has not been fully evaluated. More research is required in this actively growing area.