Bleeding after cardiopulmonary bypass remains a significant problem for the cardiac surgeon. In addition to surgically-induced bleeding, the major cause of loss of blood is an acquired coagulopathy. Impaired function, produced either by the mechanical effect of cardiopulmonary bypass or by the influence of hemostatic activation of platelets during bypass, is the main cause of postoperative bleeding. The tendency towards bleeding in infants and neonates is additionally influenced by the type of operation, those with cyanotic heart disease demonstrating an increased tendency to bleeding. Most of the procedures are more complex than in adults, and many reoperations are necessary, particularly if primary correction is not possible. Furthermore, procedures for perfusion and cooling are mostly different from those used in adults. The operations are regularly performed using deep hypothermia or circulatory arrest, which may further impair the function of platelets. Yet the effect of low temperatures on hemostasis, with or without circulatory arrest, still remains unclear, since the immature system for coagulation in neonates may contribute to impaired hemostasis.
Closed-chest left heart bypass without anticoagulation