Two-minute disconnection technique with a double-lumen tube to speed the collapse of the non-ventilated lung for one-lung ventilation in thoracoscopic surgery

BACKGROUND: Thoracic surgery requires the effective collapse of the non-ventilated lung. In the majority of cases, we accomplished, accelerated lung collapse using a double-lumen tube (DLT). We hypothesized that using the two-minute disconnection technique with a DLT would improve lung collapse during subsequent one-lung ventilation. METHODS: Fifty patients undergoing thoracoscopic surgery with physical classification I or II according to the American Society of Anesthesiologists were randomly divided into two groups for respiratory management of one-lung ventilation (OLV). In group N, OLV was initiated after the DLT was disconnected for 2 min; the initiation time began when the surgeon made the skin incision. In group C, OLV was initiated when the surgeon commenced the skin incision and scored the quality of lung collapse (using a four-point ordinal scale). The surgeon’s satisfaction or comfort with the surgical conditions was assessed using a visual analogue scale. rSO(2) level, mean arterial pressure, pulse oxygen saturation, arterial blood gas analysis, intraoperative hypoxaemia, intraoperative use of CPAP during OLV, and awakening time were determined in patients at the following time points: while inhaling air (T(0)), after anaesthesia induction andinhaling 100% oxygen in the supine position under double lung ventilation for five mins (T(1)), at two mins after skin incision (T(2)), at ten mins after skin incision (T(3)), and after the lung recruitment manoeuvres and inhaling 50% oxygen for five mins (T(4)). RESULTS: The two-minute disconnection technique was associated with a significantly shorter time to total lung collapse compared to that of the conventional OLV ventilation method (15 mins vs 22 mins, respectively; P < 0.001), and the overall surgeon’s satisfaction was higher (9 vs 7, respectively; P < 0.001). At T(2), the PaCO(2), left rSO(2) and right rSO(2) were higher in group N than in group C. There were no statistically significant differences between the incidence of intraoperative hypoxaemia and intraoperative use of CPAP during OLV (10% vs 5%, respectively; P = 1.000), duration of awakening (18 mins vs 19 mins, respectively; P = 0.616). CONCLUSIONS: A two-minute disconnection technique using a double-lumen tube was used to speed the collapse of the non-ventilated lung during one-lung ventilation for thoracoscopic surgery. The surgeon was satisfied with the surgical conditions. TRIAL REGISTRATION: Chinese Clinical Trial Registry number, ChiCTR-IPR-17010352. Registered on Jan, 7, 2017.