Normally a lack of oxygen to the brain for more than 5 minutes causes irreversible damage. The brain is an important organ of the human body, and brain tissue is less tolerant to oxygen deprivation; once the oxygen supply is interrupted, brain cells in the brain tissue will die. If brain cells are in a state of long-term hypoxia, the damage caused to the brain is irreversible and may even cause brain death. Brain tissue has glucose to provide nutrient support, within 2~4 minutes of hypoxia, the glucose in brain tissue will be exhausted, more than 5 minutes, the oxygen content in the brain will be drastically reduced, and the brain will not be supplied with oxygen, thus causing irreversible brain damage. Normally, it is recommended that the treatment time for cerebral anoxia should be limited to 5 minutes, because the shorter the interval between cerebral anoxia, the better the effect of the treatment, and therefore the probability of the patient’s awakening will also increase.