Cardiopulmonary bypass during cardiac surgery can impair haemostasis and contribute to bleeding. There is no evidence that prophylactic use of FFP, cryoprecipitate and platelets reduces bleeding, but blood components may be used to correct dilutional coagulopathy consequent on blood loss. Platelets are frequently used but with modern bypass methods there is no evidence to show any benefit in the absence of significant thrombocytopenia or a specific platelet defect. Antifibrinolytic agents (aprotinin and tranexamic acid) have been consistently shown to reduce blood loss in cardiac surgery in both high-risk and routine patients. Aprotinin is usually reserved for those in whom bleeding is likely to be severe. DDAVP may reduce blood loss in heavy bleeders but has been associated with increased risk of arterial thrombosis. Thromboelastography and other near-patient tests of haemostasis may be helpful in guiding treatment, although their value has not been rigorously established. For patients who need to continue taking aspirin until their operation, aprotinin may partially offset the anti-platelet effect.
Note: Recent reports suggest aprotinin may have previously unrecognised risks (see Aprotinin).