Pleural fluid drains are usually removed on day 2-3 after closed chest drainage. The indications for removal of a chest drain are that the daily drainage from the chest drain is less than 100 ml, that the drainage is relatively light, and that there is no gas escaping when coughing. If the drain is placed after thoracic surgery, it is usually removed on the third postoperative day because the pleural fluid is darker in color and larger in volume on the first day, and the amount of drainage is usually less than 100 ml on the third day, so it is usually removed on the third day. In addition, there is a part of the drainage fluid is more, in about 200ml, the color is lighter, there is no bubble overflow when coughing, can also be removed. After 2 days of removal, the chest X-ray will be rechecked to see if there is any pleural effusion, if not, you can be discharged from the hospital, if there is, you can have a thoracentesis to extract the fluid.