Respiratory failure is a syndrome in which the ventilation and ventilation of the respiratory system are severely impaired due to various acute and chronic diseases, so that the body cannot exchange gas effectively with the outside world, resulting in hypoxia or hypercapnia, and causing a series of clinical changes. According to the results of arterial blood gas analysis, it can be divided into type I respiratory failure and type II respiratory failure, and the difference between the two is usually manifested in the following aspects: 1, blood gas analysis indicators are different: type I respiratory failure simply appears hypoxemia, partial pressure of oxygen <60mmHg. type II respiratory failure, that is, hypercapnic respiratory failure, blood gas analysis shows that the partial pressure of oxygen <60mmHg is accompanied by partial pressure of carbon dioxide > 50 mmHg; 2. Different etiology: Type I respiratory failure is the dysfunction of ventilation caused by pulmonary parenchymal and pulmonary vascular lesions, and common diseases include pneumonia, pulmonary fibrosis, pulmonary embolism and pulmonary edema caused by various reasons. Type II respiratory failure is mainly ventilation dysfunction caused by pump failure, and common diseases include chronic obstructive pulmonary disease, severe bronchial asthma, central nervous system diseases, etc.; 3. Different pathogenesis: Type I respiratory failure, mainly includes diffusion dysfunction, increased venous anatomical shunt, increased oxygen consumption, etc. Type II respiratory failure is usually due to obstructive ventilatory dysfunction, resulting in hypoxia and carbon dioxide retention, accompanied by disorders of diffusion function and ventilatory blood flow ratio; 4. Different clinical symptoms: Type I respiratory failure manifests as obvious hypoxia, such as dyspnea, cough, cough, breathlessness and apathy, causing damage to the central nervous system, circulatory system, renal function and digestive system. Type II respiratory failure on the basis of the symptoms of type I respiratory failure, due to carbon dioxide retention, patients can develop headache, irritability, slurred speech, confusion, drowsiness, coma, respiratory depression and other symptoms, also known clinically as pulmonary encephalopathy, also known as carbon dioxide anesthesia; 5. Treatment is different: Type I respiratory failure is mostly high-flow oxygenation, if the effect of oxygenation is not good, tracheal intubation is performed when necessary. Keep the airway unobstructed, improve hypoxia, correct metabolic disorders, prevent and control multi-organ functional damage, and actively treat the original disease. Type II respiratory failure requires continuous low-flow oxygenation because high-flow oxygenation in patients with type II respiratory failure can cause respiratory depression and lead to further increase in carbon dioxide retention, so low-flow oxygenation is clinically required. It is also necessary to unblock the airway, expectorate and stop coughing, and give anti-infection, release bronchospasm or nebulization treatment.