Coma is a complete loss of consciousness, usually with voluntary respiration, and is related to the degree of coma. 1, shallow coma when the respiratory rhythm is relatively stable, moderate coma and deep coma, there are respiratory rhythm disorders, irregular respiration, serious condition with voluntary respiratory arrest. If the patient’s heart is not failing and the blood pressure and voluntary heartbeat are stable, the comatose patient can still prolong the survival time even if the respiration is unstable or there is no voluntary respiration. 3. However, if the comatose patient’s voluntary breathing stops, it is too late for tracheal intubation and ventilator-assisted ventilation, and the patient dies quickly.