Outcomes of chest drain management using only air leak (without fluid) criteria for removal after general thoracic surgery—a drainology study

BACKGROUND: Chest drain management is a variable aspect of postoperative care in thoracic surgery, with different opinion for air and drain volume output. We aim to study if acceptable safety was maintained using air leak criteria alone. METHODS: A 9-year retrospective analysis of protocolised chest drain management using digital drain air leak cut off less than 20 mL/min for more than 6 h for drain removal in patients undergoing general thoracic surgery. We excluded patients if a chest drain was not required nor removed during admission or if patients underwent volume reduction or pneumonectomy. Withdrawal criteria were suspected bleeding or chylothorax. Postoperative films were reviewed to document post-drain removal pneumothorax, pleural effusion, and reintervention (drain re-insertion). RESULTS: Between 2012 and 2021, 1,187 patients had thoracic surgery under a single surgeon. Following exclusion and withdrawal criteria, 797 patients were left for analysis. The mean age [standard deviation (SD)] was 61 [16] years and 383 (48%) were male. Median [interquartile range (IQR)] duration of drain insertion was 1 [1–2] day with a median length of hospital stay of 4 [2–6] days. Post-drain removal pneumothorax was observed in 141 (17.7%), post-drain removal pleural effusion was observed in 75 (9.4%) and re-intervention (reinsertion of chest drain) required in 17 (2.1%). CONCLUSIONS: Our results demonstrate acceptable levels of safety using digital assessment of air leak as the sole criteria for drain removal in selected patients after general thoracic surgery.