Bronchial suction does not facilitate lung collapse when using a double-lumen tube during video-assisted thoracoscopic surgery: a randomized controlled trial.

Background: Bronchial suction through the lumen of a bronchial blocker has been reported to accelerate lung collapse. The aim of the current study was to examine whether bronchial suction could also facilitate lung collapse when using a double-lumen tube (DLT). Methods: Eighty patients scheduled for elective video-assisted thoracoscopic surgery for lung cancer using a DLT for one-lung ventilation (OLV) were randomised into an arm that received bronchial suction and an arm that underwent spontaneous collapse (n=40 per arm). For bronchial suction, a pressure of -30 cmH(2)O was applied to the lumen of the non-ventilated lung during the first minute of OLV. The primary endpoint was the degree of lung collapse at 10 min after the start of OLV, assessed on a 10-point visual analogue scale (0: fully inflated; 10: complete collapse). Secondary outcomes included lung collapse at 1 and 5 min after the start of OLV, as well as occurrence of intraoperative hypoxemia. Results: Median (interquartile range) lung collapse scores at 10 min were statistically greater in the bronchial suction arm than in the spontaneous collapse arm [9.0 (9.0-9.0) vs. 8.5 (8.0-9.0); P=0.004]. Lung collapse was also statistically greater in the bronchial suction arm at 5 min [8.0 (7.0-8.0) vs. 7.0 (6.25-7.0) min; P=0.002] and 1 min [4.0 (4.0-5.0) vs. 2.0 (2.0-2.0) min; P<0.001]. None of the patients experienced intraoperative hypoxemia and operative complications. Conclusions: Bronchial suction resulted in statistically greater but not clinically meaningful lung collapse when using a DLT. However, greater degree of lung collapse at 1-min could be helpful in reducing accidental injuries.