Prospective randomized trial compares suction versus water seal for air leaks

Background. Surgeons treat air leaks differently. Our goal was to evaluate whether it is better to place chest tubes on suction or water seal for stop ping air leaks after pulmonary surgery. A second goal was to evaluate a new classification system for air leaks that we developed. Methods. Patients were prospectively randomized before surgery to receive s uction or water seal to their chest tubes on postoperative day (POD) #2. Ai r leaks were described and quantified daily by a classification system and a leak meter. The air-leak meter scored leaks from 1 (least) to 7 (greatest ). The group randomized to water seal stayed on water seal unless a pneumot horax developed. Results. On POD #2, 33 of 140 patients had an air leak. Eighteen patients h ad been preoperatively randomized to water seal and 15 to suction. Air leak s resolved in 12 (67%) of the water seal patients by the morning of POD #3. All 6 patients whose air leak did not stop had a leak that was 4/7 or grea ter (p < 0.0001) on the leak meter. Of the 15 patients randomized to suctio n, only 1 patient's air leak (7%) resolved by the morning of POD #3. The ra ndomization aspect of the trial was ended and statistical analysis showed w ater seal was superior (p = 0.001). The remaining 14 patients were then pla ced to water seal and by the morning of POD #4, 13 patients' leaks had stop ped. Of the 32 total patients placed to seal, 7 (22%) developed a pneumotho rax and 6 of these 7 patients had Leaks that were 4/7 or greater (p = 0.001 ). Conclusions. Placing chest tubes on water seal seems superior to wall sucti on for stopping air leaks after pulmonary resection. However, water seal do es not stop expiratory leaks that are 4/7 or greater. Pneumothorax may occu r when chest tubes are placed on seal with leaks this large. (Ann Thorac Su rg 2001;71:1613-7) (C) 2001 by The Society of Thoracic Surgeons.