Abstract: Objective To evaluate the application ofprotective ventilation(PV) versus conventional ventilation(CV)for surgery in the prone position. Methods We searchedPubMed, Embase, the Cochrane Library, WanFang Dataand other Chinese databases to collect the randomized controlled trails (RCTs) on intraoperative PV in comparison with CVfor surgery in the prone position.Two authors independently identified the studies, performed data extraction and assessed the risks of bias in the included studiesaccording tothe Cochrane Handbook for Systematic Reviews of Interventions. The reviewers conducted data analyses with RevMan software. Results A total of 9 RCTs involving 449participants were included.The resultsshowed that the incidence of postoperative pulmonary complications (RR 0.30, 95% CI 0.12~0.73, P<0.01) and peak pressure (MD -3.52, 95% CI -6.93~-0.11, P<0.05) were lower in the PV group. Intraoperative PaO2/FiO2was higher (MD 37.28, 95% CI 22.67~51.89, P<0.001) and alveolar-arterial oxygen difference was lower(MD -45.50, 95% CI -61.35~-29.65, P<0.001) in the PV group. Conclusions Application of low tidal volume ventilationin combination withpositiveend-expiratory pressure(with or without recruitment maneuver)decreases postoperative pulmonary complications, reduces peak pressure and improves oxygenationfor surgery in the prone position.

Key words: protective ventilation, prone position, positive-pressure respiration, recruitment maneuver