Anticoagulation during extracorporeal life support

Extracorporeal life support is a modified form of cardiopulmonary bypass used in patients with respiratory and/or cardiac failure in whom conventional therapy has failed and it is believed that the underlying organ dysfunction is reversible. During the provision of extracorporeal life support there is continuous contact between circulating blood and the foreign surfaces of the extracorporeal circuit. This exposure of blood to non-biologic surfaces initiates a complex inflammatory response which includes activation of procoagulant mechanisms. Anticoagulation is used in an effort to prevent thrombosis in the extracorporeal circuit. Despite attempts to balance procoagulant and anticoagulant activity, both bleeding complications and thrombosis do occur. Heparin is the most common anticoagulant used in extracorporeal support. Unfortunately, there are a number of shortcomings of heparin anticoagulation and the available methods to monitor heparin activity, particularly so in infants and children. There are a number of novel anticoagulants and anticoagulant strategies on the horizon including surface modification of the extracorporeal circuit which will hopefully lead to limitation of both bleeding and thrombotic complications in patients receiving extracorporeal life support.