The National Blood Service for England collects, tests, processes, stores, and issues 2.1 million blood donations each year, and the optimal use of this scarce resource is of paramount importance. Allogeneic red blood cell (RBC) transfusion is associated with wellknown adverse effects. These include febrile, anaphylactic, and haemolytic transfusion reactions, transfusion-related acute lung injury, and transfusion-associated circulatory overload. In addition, although rare, there are infection risks of viral, bacterial, parasitic, or prion transmission. In the laboratory setting, allogeneic blood has been shown to depress the immune function. Historically, there was also concern over the potential for increased risk of cancer recurrence related to allogeneic blood. In critically ill patients, blood transfusions have been associated with increased risk of sepsis, prolonged requirement for mechanical respiratory support, and multiple-organ dysfunction. 1 Autologous blood use is theoretically attractive as being less harmful than donated, allogeneic blood. Methods for collecting and using autologous blood include predeposition, perioperative normovolaemic haemodilution, and intraoperative or postoperative cell salvage. Cell salvage is the most effective mechanism, and its use was endorsed by the Chief Medical Officer in England as a key component of the Department of Health 'Better Blood Transfusion Initiative'. Basic principles Cell salvage is the process by which blood from the surgical field is collected, filtered, and washed to produce autologous blood for transfusion back to the patient. This technique can be used during the intra-or postoperative periods. The technology of cell salvage has evolved since its inception in the 1960s. Initially, cell salvage was limited to simply filtering blood loss during surgery by gravity. More modern devices collect blood to which is added heparinized normal saline or citrate anticoagulant. Processing the collected blood
