Operative procedures on the pleural space are usually managed by chest tube drainage. Timing for removing the tube is empirically established, with wide variation among surgeons. Our objective was to evaluate the effectiveness and safety of establishing a volume of 200 mL/d of uninfected drainage as a threshold for removal of chest tube, as compared with more frequently used volumes of 100 and 150 mL/d.

A prospective randomized study was performed in a single institution. Patients (n = 139) submitting to pleural drainage after surgical procedures were randomized to one of three groups, defined by the planned timing of chest tube removal (depending on the threshold volume per day of pleural fluid drained): G-100 (≤100 mL/d, n = 44); G-150 (≤150 mL/d, n = 58); and G-200 (≤200 mL/d, n = 37). Subsequently, another 91 consecutive patients had chest tubes removed when drainage was less than 200 mL/d (G-val, prospective validation group). All patients had similar discharge and 60-day followup. Drainage time, hospital stay, and reaccumulation rate were registered.

Drainage time (median days: 3.5 for G-100, 3 for G-150, 3 for G-200, 3 for G-val) and hospital stay (median days: 4 for G-100, 3 for G-150, 3 for G-200, 3 for G-val) were not statistically different among groups. Radiologic reaccumulation rates were 9.1% for G-100, 13.1% for G-150, 5.4% for G-200, and 10.9% for G-val, and the thoracenteses rates were 2.3%, 0.8%, 2.7%, and 3.3%, respectively, with no major differences among groups (G-100 versus G-150 versus G-200; G-200 versus G-val).

Increasing the threshold of daily drainage to 200 mL before removing the chest tube did not markedly affect drainage, hospitalization time, or overall costs, nor did it increase the likelihood of major pleural fluid reaccumulation. This volume (200 mL/d) could be recommended for chest tube withdrawal decision for uninfected pleural fluid with no evidence of air leaks.