This ELSO training manual is directed at intensivists, surgeons, pediatricians, residents, perfusionists, nurses and ECMO (extracorporeal membrane oxygenation) technologists involved in the care of patients with respiratory or cardiac failure which may require extracorporeal support. It provides specific information on the mechanics of ECMO, the equipment required, the physiology of extracorporeal support, and the management of patients supported on ECMO. Current results of ECMO and alternative support options are also reviewed in some chapters of this book. The authors' goal is to present clinically useful information in a manner that enables the reader to rapidly assess clinical situations, troubleshoot problems, and understand the expected results of therapy. Today, ECMO support has an important role in most major medical centers caring for critically-ill patients, whether for neonatal respiratory failure, cardiac failure, or for cardiopulmonary support after cardiac surgery or thoracic organ transplantation. No doubt new applications and refinements of this technology will appear in the future.