The characteristics of a critically ill patient with a new type of pneumonia are clearly defined in the fifth edition of the treatment guidelines as the following three: 1. the presence of respiratory failure requiring mechanical ventilation, i.e., the patient is no longer able to breathe on his own, the blood oxygen concentration is very low, and mechanical ventilation with a ventilator is required. In such cases, patients need to be actively cared for and managed; 2. Patients with symptoms of shock are also critical patients; 3. Patients with combined failure of other organs need to be monitored and treated in ICU, i.e. intensive care unit at all times. In addition, although the patient is not critically ill, it is still necessary to pay attention to prevent other complications and the progress of the underlying disease. Content source: Dr. You Lai