<unk>  is used on people in cardiac arrest in order to oxygenate the blood and maintain a cardiac output to keep vital organs alive. Blood circulation and oxygenation are required to transport oxygen to the tissues. The physiology of<unk>  involves generating a pressure gradient between the arterial and venous vascular beds;<unk>  achieves this via multiple mechanisms The brain may sustain damage after blood flow has been stopped for about four minutes and irreversible damage after about seven minutes. Typically if blood flow ceases for one to two hours, then body cells die. Therefore, in general<unk>  is effective only if performed within seven minutes of the stoppage of blood flow. The heart also rapidly loses the ability to maintain a normal rhythm. Low body temperatures, as sometimes seen in near-drownings, prolong the time the brain survives. Following cardiac arrest, effective<unk>  enables enough oxygen to reach the brain to delay brain stem death, and allows the heart to remain responsive to defibrillation attempts.
Cardiopulmonary resuscitation
Extracorporeal cardiopulmonary resuscitation
Cardiopulmonary bypass
Extracorporeal membrane oxygenation
Rapid sequence induction
Mouth-to-mouth resuscitation
Resuscitation
Resuscitative thoracotomy