Patients in coma often have an obstructed, unobstructed airway, and the main cause is respiratory failure, including central respiratory failure as well as peripheral respiratory failure. There are several methods to keep the airway open: 1. tracheal intubation or tracheotomy, which is a physical method to keep the airway open, can be used after intubation or tracheotomy, using a ventilator to assist breathing, while paying attention to the chymotrypsin drops in the airway to prevent the formation of sputum crusts in the airway, blocking the airway. 2. use of drugs to dilate the bronchi, release the tracheal spasm, and phlegm to promote the discharge of sputum The use of anti-infective drugs to control lung infection and reduce sputum production reduces the possibility of respiratory obstruction. 4. respiratory stimulants can be used when necessary, but generally this is only used in central respiratory failure or for resuscitation. .