Effect of Intensive vs Moderate Alveolar Recruitment Strategies Added to Lung-Protective Ventilation on Postoperative Pulmonary Complications: A Randomized Clinical Trial

Importance Perioperative lung-protective ventilation has been recommended to reduce pulmonary complications after cardiac surgery. The protective role of a small tidal volume (V T ) has been established, whereas the added protection afforded by alveolar recruiting strategies remains controversial. Objective To determine whether an intensive alveolar recruitment strategy could reduce postoperative pulmonary complications, when added to a protective ventilation with small V T . Design, Setting, and Participants Randomized clinical trial of patients with hypoxemia after cardiac surgery at a single ICU in Brazil (December 2011-2014). Interventions Intensive recruitment strategy (n=157) or moderate recruitment strategy (n=163) plus protective ventilation with small V T . Main Outcomes and Measures Severity of postoperative pulmonary complications computed until hospital discharge, analyzed with a common odds ratio (OR) to detect ordinal shift in distribution of pulmonary complication severity score (0-to-5 scale, 0, no complications; 5, death). Prespecified secondary outcomes were length of stay in the ICU and hospital, incidence of barotrauma, and hospital mortality. Results All 320 patients (median age, 62 years; IQR, 56-69 years; 125 women [39%]) completed the trial. The intensive recruitment strategy group had a mean 1.8 (95% CI, 1.7 to 2.0) and a median 1.7 (IQR, 1.0-2.0) pulmonary complications score vs 2.1 (95% CI, 2.0-2.3) and 2.0 (IQR, 1.5-3.0) for the moderate strategy group. Overall, the distribution of primary outcome scores shifted consistently in favor of the intensive strategy, with a common OR for lower scores of 1.86 (95% CI, 1.22 to 2.83; P  = .003). The mean hospital stay for the moderate group was 12.4 days vs 10.9 days in the intensive group (absolute difference, −1.5 days; 95% CI, −3.1 to −0.3; P  = .04). The mean ICU stay for the moderate group was 4.8 days vs 3.8 days for the intensive group (absolute difference, −1.0 days; 95% CI, −1.6 to −0.2; P  = .01). Hospital mortality (2.5% in the intensive group vs 4.9% in the moderate group; absolute difference, −2.4%, 95% CI, −7.1% to 2.2%) and barotrauma incidence (0% in the intensive group vs 0.6% in the moderate group; absolute difference, −0.6%; 95% CI, −1.8% to 0.6%; P  = .51) did not differ significantly between groups. Conclusions and Relevance Among patients with hypoxemia after cardiac surgery, the use of an intensive vs a moderate alveolar recruitment strategy resulted in less severe pulmonary complications while in the hospital. Trial Registration clinicaltrials.gov Identifier:NCT01502332