the swabs with saline, he found that he could re-infuse the result of the washings. this unsophisticated method resulted in a 75% mortality rate, but it marked the start of autologous blood transfusion. during the american civil war union army physicians are said to have administered four transfusions. in 1886, j. duncan used autotransfusion during the amputation of limbs by removing blood from the amputated limb and returning it to the patient by femoral injection. this method was apparently fairly successful. a german, m. j. theis, reported the first successful use of intraoperative autotransfusion in 1914, with a ruptured ectopic pregnancy. the earliest report in the american literature on the use of autotransfusion was by lockwood in 1917 who used the technique during a splenectomy for banti syndrome. interest in the unrefined technique of autotransfusion continued through to the early 1940s, and was applied to various procedures including treatment of ectopic pregnancy, hemothorax, ruptured spleen, perforating abdominal injuries, and neurosurgical procedures. the interest in autotransfusion dwindled during world war ii, when there was a large pool of donors. after the war, blood testing, typing, and crossmatching techniques were improved making blood banks the answer to the increased demand for blood. in the 1960s, interest in autotransfusion revived. with the advances in all fields of surgery, new companies developed autotransfusion devices. problems still arose, however, with air embolism, coagulopathy, and hemolysis. the devices used during the korean and vietnam war collected and provided gross filtration of blood before it was reinfused. with the introduction of cardiopulmonary bypass in 1952, autotransfusion became an area of study. klebanoff began a new era of autotransfusion by developing the first commercially available autotransfusion unit in 1968. his system, the bentley autotransfusion system aspirated, collected, filtered and reinfused autologous whole blood shed from the operative field. the problems with the bentley system included the requirement of systemic anticoagulation of the patient, introduction of air embolism, and renal failure resulting from unfiltered particulate in the reinfused blood. as the bentley system lost favor wilson and associates proposed the use of a discontinuous flow centrifuge process for autotransfusion which would wash the red cells with normal saline solution. in 1976, this system was introduced by haemonetics corp. and is known commonly as "cell saver". more recently in 1995 fresenius introduced a continuous autotransfusion system. there are three types of systems: un-washed filtered blood; discontinuous flow centrifugal; and continuous flow centrifugal. the unwashed systems are popular because of their perceived inexpense and simplicity. however unwashed systems can cause increase potential for clinical complications. the washed system requires a properly trained and clinically skilled operator. it returns only red blood cells suspended in saline and is rarely associated with any clinical complications. discontinuous autotransfusion can practically eliminate the need for exposure to homologous blood in elective surgical patients and can greatly reduce the risk of exposure to emergency surgical patients. society and culture individuals of the jehovah's witness religion in particular refuse to accept homologous and autologous pre-donated blood. however some individual members may accept the use of autotransfusion by means of the cell saver. the process of autotransfusion using the cell saver is modified to maintain a continuous circuit of blood that maintains continuous contact with the body. this process when carefully explained to the patient may be acceptable when a patient otherwise refuses based on religious beliefs. platelet sequestration and autologous platelet gel many of the newest autotransfusion machines are programmable to provide separation of blood into three groups; red cells, platelet poor plasma, and platelet rich plasma. blood can be drawn from the patient just prior to surgery and then separated. the separated blood components which have been sequestered can be stored during the surgical procedure. the red cells and platelet poor plasma can be given back to the patient through intravenous transfusion during or after surgery. the platelet rich plasma can be mixed with calcium and thrombin to create a product known as autologous platelet gel. this is an autologous product that can be used for a variety of techniques including use as a hemostatic aid, a dural sealant, and an aid to fusion of bone.