IMPORTANCE An intraoperative higher level of positive end-expiratory positive pressure (PEEP) with alveolar recruitment maneuvers improves respiratory function in obese patients undergoing surgery, but the effect on clinical outcomes is uncertain. OBJECTIVE To determine whether a higher level of PEEP with alveolar recruitment maneuvers decreases postoperative pulmonary complications in obese patients undergoing surgery compared with a lower level of PEEP. DESIGN, SETTING, AND PARTICIPANTS Randomized clinical trial of 2013 adults with body mass indices of 35 or greater and substantial risk for postoperative pulmonary complications who were undergoing noncardiac, nonneurological surgery under general anesthesia. The trial was conducted at 77 sites in 23 countries from July 2014-February 2018; final follow-up: May 2018. INTERVENTIONS Patients were randomized to the high level of PEEP group (n = 989), consisting of a PEEP level of 12 cm H 2 O with alveolar recruitment maneuvers (a stepwise increase of tidal volume and eventually PEEP) or to the low level of PEEP group (n = 987), consisting of a PEEP level of 4 cm H 2 O. All patients received volume-controlled ventilation with a tidal volume of 7 mL/kg of predicted body weight. MAIN OUTCOMES AND MEASURES The primary outcome was a composite of pulmonary complications within the first 5 postoperative days, including respiratory failure, acute respiratory distress syndrome, bronchospasm, new pulmonary infiltrates, pulmonary infection, aspiration pneumonitis, pleural effusion, atelectasis, cardiopulmonary edema, and pneumothorax. Among the 9 prespecified secondary outcomes, 3 were intraoperative complications, including hypoxemia (oxygen desaturation with SpO 2 Յ92% for >1 minute). RESULTS Among 2013 adults who were randomized, 1976 (98.2%) completed the trial (mean age, 48.8 years; 1381 [69.9%] women; 1778 [90.1%] underwent abdominal operations). In the intention-to-treat analysis, the primary outcome occurred in 211 of 989 patients (21.3%) in the high level of PEEP group compared with 233 of 987 patients (23.6%) in the low level of PEEP group (difference, −2.3% [95% CI, −5.9% to 1.4%]; risk ratio, 0.93 [95% CI, 0.83 to 1.04]; P = .23). Among the 9 prespecified secondary outcomes, 6 were not significantly different between the high and low level of PEEP groups, and 3 were significantly different, including fewer patients with hypoxemia (5.0% in the high level of PEEP group vs 13.6% in the low level of PEEP group; difference, −8.6% [95% CI, −11.1% to 6.1%]; P < .001). CONCLUSIONS AND RELEVANCE Among obese patients undergoing surgery under general anesthesia, an intraoperative mechanical ventilation strategy with a higher level of PEEP and alveolar recruitment maneuvers, compared with a strategy with a lower level of PEEP, did not reduce postoperative pulmonary complications.

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Background: Postoperative cardiovascular and pulmonary complications (PCVCs and PPCs) are frequent and result in prolonged hospital stay. The aim of this study was to update the risk factors associated with major complications and survival after lung cancer surgery. Methods: This is a post-hoc analysis of a randomized controlled trial that was designed to assess the benefits of preoperative physical training. After enrollment, clinical, biological and functional data as well as intraoperative details were collected. In-hospital PCVCs and PPCs were recorded and survival data were adjudicated up to 4 years after surgery. Results: Data from 151 patients were analyzed. Thirty-day mortality rate was 2.6% and the incidence of PCVCs and PPCs was 15% and 33%, respectively. Stepwise logistic regression analysis showed that, PCVCs were mainly related to elevated plasma levels of brain natriuretic peptides [odds ratios (ORs) =6.0; 95% confidence interval (CI), 1.3-27.3] and performance of a pneumonectomy (OR =9.6; 95% CI, 2.9-31.5) whereas PPCs were associated with the presence of COPD (OR =5.9; 95% CI, 2.4-14.8), current smoking (OR =2.6; 95% CI, 1.1-6.5) and the need for blood transfusion (OR =5.2; 95% CI, 1.2-23.3). Preoperative physical training was a protective factor regarding PPCs (OR =0.13; 95% CI, 0.05-0.34). Cox proportional hazards regression analysis showed that ventilatory inefficiency during exercise (expressed by a ratio >40 of ventilation to carbon dioxide elimination), coronary artery disease, elevated plasma levels of brain natriuretic peptides and the occurrence of PPCs were all predictive of poor survival after surgery. Conclusions: Besides smoking and the extent of lung resection, preexisting cardiopulmonary disease as evidence by elevated levels of brain natriuretic peptides and inefficient ventilation are associated with poor clinical outcome after lung cancer surgery.