Gas poisoning, also known as carbon monoxide poisoning. In case of gas poisoning, the patient should first be transferred to a safe environment. For example, in case of gas poisoning at home, it is recommended to open doors and windows quickly to promote indoor air circulation. The patient should rest quietly to avoid aggravating the burden on the heart and lungs and increasing oxygen consumption after activity. At the same time, untie the patient’s collar to avoid respiratory difficulties due to the tightness of the collar. Clean the airway in time to avoid asphyxiation. For severely poisoned patients who are unconscious and have cherry-red skin and mucous membranes, call 120 in time, and at the same time suggest the rescuer to carry out artificial cardiopulmonary resuscitation, i.e. extracorporeal cardiac compression and artificial respiration in time. Let the patient lie on his back on the flat ground, the rescuer will put the root of the palm of one hand on the middle and lower 1/3 junction of the patient’s sternum, and place the root of the palm of the other hand on the first hand, with the fingers not touching the chest wall. The elbows should be straightened and pressed vertically downward, the frequency of adult compression is 100-120 times/min, the depth of downward compression is 5-6cm, and the thorax should be fully recovered after each compression. Artificial respiration and chest compressions should be repeated according to the ratio of 2:30 until the patient recovers spontaneous respiration, which can be stopped. For patients with gas poisoning, to correct the lack of oxygen in the body, the first choice of hyperbaric oxygen therapy, generally within 4 hours after poisoning is more effective, and the number of treatments try to be greater than 20 times. If the patient is in a deep coma, there may be cerebral edema or even brain hernia and other complications, it is recommended to give dehydration, lowering the cranial pressure treatment, to prevent cerebral edema caused by cerebral hernia and other complications. Gas poisoning can damage the cerebral cortex and cause neural demyelinating lesions, and severe patients may develop delayed encephalopathy. In addition to hyperbaric oxygen therapy, supplementation of B vitamins, cytarabine, and cerebro-activator under the guidance of a specialized physician is required to promote the recovery of brain cell function.