Due to excessive secretions in the respiratory tract, it is necessary at this time to keep the airway open by suctioning the sputum out of the airway by suction technique. Generally, the pressure of suction device is 300-400mmHg for adults and less than 300mmHg for children, and the pressure of suction is adjusted according to different conditions. During the process of aspiration, the patient’s vital signs should be observed at any time, and if there is a drop in blood pressure or abnormal heartbeat or breathing, the aspiration should be stopped at any time to keep the vital signs stable. In the process of aspiration, you can choose to insert the aspiration tube 22-25cm by nasal suction, or 14-16cm by oral suction, and if necessary, aspirate by tracheal intubation or tracheotomy, and each aspiration should not exceed 15s with 3-5min interval.