A technique (available at only 5 hospitals in the UK) used when a patient has a critical condition which prevents the lungs or heart from working normally. The ECMO machine is very similar to heart/lung machines used during open-heart surgery. It is a supportive measure that uses an artificial lung (the membrane) to oxygenate the blood outside the body (extracorporeal) until the patient recovers sufficiently to be maintained by more conventional methods of ventilation.