<unk>  <unk>  is a technique in which a machine temporarily takes over the function of the heart and lungs during surgery, maintaining the circulation of blood and the oxygen content of the patient's body. The<unk>  pump itself is often referred to as a heart–lung machine or "the pump".<unk>  pumps are operated by perfusionists.<unk>  is a form of extracorporeal circulation. Extracorporeal membrane oxygenation is generally used for longer-term treatment.<unk>  mechanically circulates and oxygenates blood for the body while<unk> ing the heart and lungs. It uses a heart–lung machine to maintain perfusion to other body organs and tissues while the surgeon works in a bloodless surgical field. The surgeon places a cannula in the right atrium, vena cava, or femoral vein to withdraw blood from the body. Venous blood is removed from the body by the cannula and then filtered, cooled or warmed, and oxygenated before it is returned to the body by a mechanical pump. The cannula used to return oxygenated blood is usually inserted in the ascending aorta, but it may be inserted in the femoral artery, axillary artery, or brachiocephalic artery (among others). The patient is administered heparin to prevent clotting, and protamine sulfate is given after to reverse effects of heparin. During the procedure, hypothermia may be maintained; body temperature is usually kept at 28 °C to 32 °C (82.4–89.6 °F). The blood is cooled during<unk>  and returned to the body. The cooled blood slows the body's basal metabolic rate, decreasing its demand for oxygen. Cooled blood usually has a higher viscosity, but the crystalloid solution used to prime the<unk>  tubing dilutes the blood.
Cardiopulmonary bypass
Extracorporeal membrane oxygenation
Extracorporeal cardiopulmonary resuscitation
Minimized extracorporeal circulation
Cardiopulmonary resuscitation
Intra-aortic balloon pump
Ventricular assist device
Resuscitative thoracotomy