Other disciplines treat patients by organ, such as cardiology and respiratory medicine, but the ICU treats patients according to the severity of the patient, and only serious patients are admitted to the ICU. The effect is also very good; 2, high-risk patients, he may usually live in a very good condition, the ability to work is also okay, but he has some basic chronic diseases. In a major blow or major surgery may be a sharp turn down, such patients in the preoperative or in some special treatment before or after the effective monitoring and observation in the ICU; 3, chronic disease suddenly aggravated patients, such as chronic bronchitis, he usually only some wheezing, can ordinary life, but once in winter suddenly because of cold or cold aggravation. This kind of patients with acute exacerbation can be effectively treated in the ICU to restore them to their original state, but their original chronic diseases may not be treated; 4, patients with advanced chronic diseases, such as patients with advanced tumors, although they are very serious, they are not admitted to the ICU because they cannot fundamentally improve the prognosis of the patients, so they cannot be benefited and are It is not effective.