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 H2O 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 H2O (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 H2O 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.