Control of Coagulation during Extracorporeal Membrane Oxygenation

The use of extracorporeal membrane oxygenation (ECMO) requires maintaining a delicate balance between the prevention of thrombosis and the avoidance of hemorrhage. Anticoagulation is necessary to maintain circuit flow. It counteracts the activation of clotting mechanisms that occurs as a result of the interaction between circulating blood and the foreign surfaces of the ECMO equipment as well as endothelial damage within the vasculature. Heparin remains the anticoagulant of choice; however, the difficulty in adjusting dosages and the risk of developing heparin-induced thrombocytopenia have led to the use of alternative therapies such as argatroban and lepirudin. In addition, thrombolysis with alteplase is now being used in patients who develop clots despite anticoagulation. Aminocaproic acid has been used for more than a decade to manage or prevent hemorrhage in patients on ECMO, but a new report suggests that activated recombinant factor VII may also be useful as a hemostatic agent. Over the next decade, it is likely that the role of these newer agents will grow, making them important tools in the management of patients on ECMO.