Non-ventilated lung deflation during one-lung ventilation with a double-lumen endotracheal tube: a randomized-controlled trial of occluding the non-ventilated endobronchial lumen before pleural opening

Purpose Lung deflation during one-lung ventilation (OLV) is thought to be faster using a double-lumen endotracheal tube (DL-ETT) than with a bronchial blocker, especially when the non-ventilated lumen is opened to allow egress of air from the operative lung. Nevertheless, ambient air can also be entrained into the non-ventilated lumen before pleural opening and subsequently delay deflation. We therefore hypothesized that occluding the non-ventilated DL-ETT lumen during OLV before pleural opening would prevent air entrainment and consequently enhance operative lung deflation during video-assisted thoracoscopic surgery (VATS). Methods Thirty patients undergoing VATS using DL-ETT to allow OLV were randomized to having the lumen of the operative lung either open (control group) or occluded (intervention group) to ambient air. The primary outcome was the time to lung collapse evaluated intraoperatively by the surgeons. The T 50 , an index of rate of deflation, was also determined from a probabilistic model derived from intraoperative video clips presented in random order to three observers. Results The median [interquartile range] time to lung deflation occurred faster in the intervention group than in the control group (24 [20–37] min vs 54 [48–68] min, respectively; median difference, 30 min; 95% confidence interval [CI], 14 to 46; P < 0.001). The estimated T 50 was 32.6 min in the intervention group compared with 62.3 min in the control group (difference, − 29.7 min; 95% CI, − 51.1 to − 8.4; P = 0.008). Conclusion Operative lung deflation during OLV with a DL-ETT is faster when the operative lumen remains closed before pleural opening thus preventing it from entraining ambient air during the closed chest phase of OLV. Trial registration www.clinicaltrials.gov (NCT03508050); registered 27 September 2017.