Background Protective ventilation may improve outcomes after major surgery. However, in the context of one-lung ventilation, such a strategy is incompletely defined. The authors hypothesized that a putative one-lung protective ventilation regimen would be independently associated with decreased odds of pulmonary complications after thoracic surgery. Methods The authors merged Society of Thoracic Surgeons Database and Multicenter Perioperative Outcomes Group intraoperative data for lung resection procedures using one-lung ventilation across five institutions from 2012 to 2016. They defined one-lung protective ventilation as the combination of both median tidal volume 5 ml/kg or lower predicted body weight and positive end-expiratory pressure 5 cm H 2 O or greater. The primary outcome was a composite of 30-day major postoperative pulmonary complications. Results A total of 3,232 cases were available for analysis. Tidal volumes decreased modestly during the study period (6.7 to 6.0 ml/kg; P < 0.001), and positive end-expiratory pressure increased from 4 to 5 cm H 2 O ( P < 0.001). Despite increasing adoption of a “protective ventilation” strategy (5.7% in 2012 vs. 17.9% in 2016), the prevalence of pulmonary complications did not change significantly (11.4 to 15.7%; P = 0.147). In a propensity score matched cohort (381 matched pairs), protective ventilation (mean tidal volume 6.4 vs. 4.4 ml/kg) was not associated with a reduction in pulmonary complications (adjusted odds ratio, 0.86; 95% CI, 0.56 to 1.32). In an unmatched cohort, the authors were unable to define a specific alternative combination of positive end-expiratory pressure and tidal volume that was associated with decreased risk of pulmonary complications. Conclusions In this multicenter retrospective observational analysis of patients undergoing one-lung ventilation during thoracic surgery, the authors did not detect an independent association between a low tidal volume lung-protective ventilation regimen and a composite of postoperative pulmonary complications. Editor’s Perspective What We Already Know about This Topic Lower tidal volume ventilation with moderate positive end-expiratory pressure (PEEP) compared with higher tidal volumes with low PEEP is associated with fewer pulmonary complications in adult respiratory distress syndrome and in abdominal surgery with two-lung ventilation. Fewer studies have assessed optimal ventilation strategies for thoracic surgery with one-lung ventilation. Optimal lung protective strategies for one-lung ventilation are undefined. What This Article Tells Us That Is New This five-center retrospective observational study evaluated records from 3,232 thoracic surgical patients who underwent one-lung ventilation for pneumonectomies, bilobectomies, single lobectomies, segmentectomies, or wedge resections. Patients with tidal volumes 5 ml/kg or lower and PEEP greater than 5 cm H 2 O did not have significantly different 30-day adverse pulmonary outcomes compared with patients not ventilated with this strategy. Higher mechanical ventilation driving pressures were not associated with composite 30-day adverse pulmonary outcome. The protective ventilation regimen tested was not associated with decreased pulmonary complications.

Background The use of lung-protective ventilation (LPV) strategies may minimize iatrogenic lung injury in surgical patients. However, the identification of an ideal LPV strategy, particularly during one-lung ventilation (OLV), remains elusive. This study examines the role of ventilator management during OLV and its impact on clinical outcomes. Methods Data were retrospectively collected from the hospital electronic medical record and the Society of Thoracic Surgery database for subjects undergoing thoracic surgery with OLV between 2012 and 2014. Mean tidal volume (V T ) during two-lung ventilation and OLV and ventilator driving pressure (ΔP) (plateau pressure − positive end-expiratory pressure [PEEP]) were analyzed for the 1,019 cases that met the inclusion criteria. Associations between ventilator parameters and clinical outcomes were examined by multivariate linear regression. Results After the initiation of OLV, 73.3, 43.3, 18.8, and 7.2% of patients received V T greater than 5, 6, 7, and 8 ml/kg predicted body weight, respectively. One hundred and eighty-four primary and 288 secondary outcome events were recorded. In multivariate logistic regression modeling, V T was inversely related to the incidence of respiratory complications (odds ratio, 0.837; 95% CI, 0.729 to 0.958), while ΔP predicted the development of major morbidity when modeled with V T (odds ratio, 1.034; 95% CI, 1.001 to 1.068). Conclusions Low V T per se ( i.e. , in the absence of sufficient PEEP) has not been unambiguously demonstrated to be beneficial. The authors found that a large proportion of patients continue to receive high V T during OLV and that V T was inversely related to the incidence of respiratory complications and major postoperative morbidity. While low (physiologically appropriate) V T is an important component of an LPV strategy for surgical patients during OLV, current evidence suggests that, without adequate PEEP, low V T does not prevent postoperative respiratory complications. Thus, use of physiologic V T may represent a necessary, but not independently sufficient, component of LPV. Abstract Analysis from 1,019 patients undergoing one-lung ventilation indicated that low tidal volume in the presence of low positive end-expiratory pressure is associated with increased pulmonary complications. This suggests that low tidal volume during one-lung ventilation is protective only when accompanied by adequate positive end-expiratory pressure.