CPR must be performed within 4-6 minutes after sudden death, because after sudden death, the person’s breathing and heartbeat have stopped, and the body will immediately appear inside the ischemia and hypoxia. If the important organs and tissues of the whole body, especially the brain, lack of blood and oxygen supply within a few minutes, it is likely to lead to irreversible damage, especially the brain cells are the most sensitive, if the lack of blood and oxygen, after 6 minutes, it is easy to lead to brain cell necrosis, even if the function of the organs of the whole body later restored, the brain may also appear long-term coma state. Cardiopulmonary resuscitation, which usually includes chest compressions and artificial respiration. Chest compressions mainly establish artificial circulation and promote blood flow throughout the body; artificial respiration mainly passively gives oxygen to the body.