The number of days a drain is placed in the lungs depends largely on the specific reason why the drain needs to be placed and the severity of the condition. Lungs due to inflammatory reactions, such as lung abscess, bronchopleural fistula, etc., need to be selected based on the amount of specific secretions being drained. The usual time frame is 3-5 days, and extubation can be considered when the amount of drainage is less than about 50 ml per day. Especially for postoperative patients with bronchopulmonary cancer, the time of drainage may be increased to observe the specific condition of the patient and try to make the lung tissues reexpand and recover to restore the normal respiratory function. When gas enters the pleural cavity and a pneumothorax develops, the drain is left in place for about 24 hours before it is removed.