title: Effect of lung-protective ventilation with lower tidal volumes on clinical outcomes among patients undergoing surgery: a meta-analysis of randomized controlled trials.
abstract: BACKGROUND
  In anesthetized patients undergoing surgery, the role of lung-protective ventilation with lower tidal volumes is unclear. We performed a meta-analysis of randomized controlled trials (RCTs) to evaluate the effect of this ventilation strategy on postoperative outcomes.
  
  
  METHODS
  We searched electronic databases from inception through September 2014. We included RCTs that compared protective ventilation with lower tidal volumes and conventional ventilation with higher tidal volumes in anesthetized adults undergoing surgery. We pooled outcomes using a random-effects model. The primary outcome measures were lung injury and pulmonary infection.
  
  
  RESULTS
  We included 19 trials (n=1348). Compared with patients in the control group, those who received lung-protective ventilation had a decreased risk of lung injury (risk ratio [RR] 0.36, 95% confidence interval [CI] 0.17 to 0.78; I2=0%) and pulmonary infection (RR 0.46, 95% CI 0.26 to 0.83; I2=8%), and higher levels of arterial partial pressure of carbon dioxide (standardized mean difference 0.47, 95% CI 0.18 to 0.75; I2=65%). No significant differences were observed between the patient groups in atelectasis, mortality, length of hospital stay, length of stay in the intensive care unit or the ratio of arterial partial pressure of oxygen to fraction of inspired oxygen.
  
  
  CONCLUSIONS
  Anesthetized patients who received ventilation with lower tidal volumes during surgery had a lower risk of lung injury and pulmonary infection than those given conventional ventilation with higher tidal volumes. Implementation of a lung-protective ventilation strategy with lower tidal volumes may lower the incidence of these outcomes.
authors.affiliation: Department of Anesthesiology (Gu, Liu), First Affiliated Hospital of Guangxi Medical University, Nanning, China; Department of Anesthesiology (Wang), General Hospital of Jinan Military Command, Jinan, China.
authors.forename: Wan-Jie
authors.initials: WJ
authors.lastname: Gu
authors.affiliation: Department of Anesthesiology (Gu, Liu), First Affiliated Hospital of Guangxi Medical University, Nanning, China; Department of Anesthesiology (Wang), General Hospital of Jinan Military Command, Jinan, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.affiliation: Department of Anesthesiology (Gu, Liu), First Affiliated Hospital of Guangxi Medical University, Nanning, China; Department of Anesthesiology (Wang), General Hospital of Jinan Military Command, Jinan, China. jingchenliu1964@sina.cn.
authors.forename: Jing-Chen
authors.initials: JC
authors.lastname: Liu
mesh_terms: D055371:Acute Lung Injury / Q000453:epidemiology / Q000517:prevention & control*; D007902:Length of Stay; D011183:Postoperative Complications / Q000453:epidemiology / Q000517:prevention & control*; D001261:Pulmonary Atelectasis / Q000453:epidemiology / Q000517:prevention & control; D016032:Randomized Controlled Trials as Topic; D012121:Respiration, Artificial / Q000009:adverse effects / Q000379:methods*; D013514:Surgical Procedures, Operative / Q000706:statistics & numerical data*; D013990:Tidal Volume; D016896:Treatment Outcome