Devices and to methods for thoracic drainage for a patient having an air fistula. A vacuum is produced in the pleural cavity of the patient by means of a suction device. In order to adjust the vacuum on the basis of objective criteria, a suitable size measure for the air fistula is determined and the vacuum produced by the suction device is controlled according to said size measure. An adaptive algorithm includes: (a) determining a first value of a size measure for the air fistula (b) changing the vacuum by a first difference value (c) determining a second value of the size measure after a first waiting period (d) changing the vacuum by a second difference value having the opposite sign if the second measure is greater than the first measure (e) repeating steps (a) to (d) after a second waiting period.