3 The procedure
3.1 Extracorporeal membrane oxygenation (ECMO) for acute heart failure in adults can be used after heart surgery to assist in the transition from cardiopulmonary bypass to ventilation. It can also be used as a bridge to myocardial recovery, cardiac transplantation or implantation of a left ventricular assist device.
3.2 There are 2 main types of ECMO – venovenous and venoarterial. For acute heart failure in adults, the venoarterial method is used. Blood is withdrawn via the venous system (usually the femoral vein or right atrium) and pumped through an oxygenator, where gas exchange of oxygen and carbon dioxide takes place. It is then returned to the arterial system (usually the femoral artery or ascending aorta). Patients are given a continuous infusion of an anticoagulant, usually heparin, to prevent blood clotting in the external system. For patients with renal insufficiency, a haemofiltration unit may be integrated into the circuit.