Ventilator therapy includes non-invasive ventilator and invasive ventilator, which are generally used to treat severe complications caused by respiratory failure, including bronchial asthma, chronic obstructive pulmonary disease, bronchiectasis, and pulmonary fibrosis. If ventilator therapy is given and the patient’s clinical symptoms are not relieved significantly or even accompanied by impaired consciousness and coma, invasive ventilator, tracheal intubation, tracheotomy and other treatments need to be given. If these treatments fail to bring about remission, it means that the patient’s condition is very serious and may be accompanied by severe respiratory failure, heart failure, and multi-system dysfunction, etc. The patient’s treatment effect is very unsatisfactory. If accompanied by sepsis, sepsis and other multi-organ dysfunction, the patient’s survival is very limited, and it is impossible to save the patient’s life despite giving active resuscitation treatment. Therefore, the failure to improve the clinical manifestations of the patient on the ventilator indicates that the patient’s condition is very critical, and he or she should be psychologically prepared.