Extracorporeal membrane oxygenation (ECMO) support is a logical means of providing time for the acutely damaged lung to heal. To be successful, the lung pathology must be reversible. There are four extracorporeal cannulation methods that can be used. Each method has its advantages and disadvantages depending upon what one wishes to accomplish; each has been successful. But ECMO in unselected patients with severe acute respiratory insufficiency is only 15-20 percent successful. The limiting factor for success is the potential reversibility of the lung pathology. Therefore, much attention is now being focused on identifying those patients who have reversible disease and would benefit from ECMO. Because serious bleeding is the biggest potential risk of ECMO therapy, antithrombogenic surfaces are being developed.