Haemostatic dysfunction and cardiopulmonary bypass: mechanisms and therapeutic choices

Cardiopulmonary bypass is characterized by multiple haemostatic defects. These are due to haemodilution, platelet damage, the effects of hypothermia, heparin administration, and, in many patients, preoperative use of aspirin. The result is often excessive blood loss. Pharmacological agents such as desmopressin, prostacyclin, and aprotinin have been introduced to improve haemostasis during cardiopulmonary bypass. The protease inhibitor aprotinin appears to be particularly promising in reduction of bleeding associated with bypass. Study of aprotinin may provide new insights into the mechanisms of haemostatic dysfunction, particularly platelet dysfunction.