title: Mechanical ventilation strategies for intensive care unit patients without acute lung injury or acute respiratory distress syndrome: a systematic review and network meta-analysis.
abstract: BACKGROUND
  It has been shown that the application of a lung-protective mechanical ventilation strategy can improve the prognosis of patients with acute lung injury (ALI) or acute respiratory distress syndrome (ARDS). However, the optimal mechanical ventilation strategy for intensive care unit (ICU) patients without ALI or ARDS is uncertain. Therefore, we performed a network meta-analysis to identify the optimal mechanical ventilation strategy for these patients.
  
  
  METHODS
  We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, EMBASE, MEDLINE, CINAHL, and Web of Science for studies published up to July 2015 in which pulmonary compliance or the partial pressure of arterial oxygen/fraction of inspired oxygen (PaO2/FIO2) ratio was assessed in ICU patients without ALI or ARDS, who received mechanical ventilation via different strategies. The data for study characteristics, methods, and outcomes were extracted. We assessed the studies for eligibility, extracted the data, pooled the data, and used a Bayesian fixed-effects model to combine direct comparisons with indirect evidence.
  
  
  RESULTS
  Seventeen randomized controlled trials including a total of 575 patients who received one of six ventilation strategies were included for network meta-analysis. Among ICU patients without ALI or ARDS, strategy C (lower tidal volume (VT) + higher positive end-expiratory pressure (PEEP)) resulted in the highest PaO2/FIO2 ratio; strategy B (higher VT + lower PEEP) was associated with the highest pulmonary compliance; strategy A (lower VT + lower PEEP) was associated with a shorter length of ICU stay; and strategy D (lower VT + zero end-expiratory pressure (ZEEP)) was associated with the lowest PaO2/FiO2 ratio and pulmonary compliance.
  
  
  CONCLUSIONS
  For ICU patients without ALI or ARDS, strategy C (lower VT + higher PEEP) was associated with the highest PaO2/FiO2 ratio. Strategy B (higher VT + lower PEEP) was superior to the other strategies in improving pulmonary compliance. Strategy A (lower VT + lower PEEP) was associated with a shorter length of ICU stay, whereas strategy D (lower VT + ZEEP) was associated with the lowest PaO2/FiO2 ratio and pulmonary compliance.
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Harbin Medical University, No 23 Youzheng St., Nangang District, Harbin, Heilongjiang, 150001, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Guo
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Harbin Medical University, No 23 Youzheng St., Nangang District, Harbin, Heilongjiang, 150001, China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Harbin Medical University, No 23 Youzheng St., Nangang District, Harbin, Heilongjiang, 150001, China.
authors.forename: Nana
authors.initials: N
authors.lastname: Zhao
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Harbin Medical University, No 23 Youzheng St., Nangang District, Harbin, Heilongjiang, 150001, China.
authors.forename: Libo
authors.initials: L
authors.lastname: Guo
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Harbin Medical University, No 23 Youzheng St., Nangang District, Harbin, Heilongjiang, 150001, China.
authors.forename: Chunjie
authors.initials: C
authors.lastname: Chi
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Harbin Medical University, No 23 Youzheng St., Nangang District, Harbin, Heilongjiang, 150001, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Hou
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Harbin Medical University, No 23 Youzheng St., Nangang District, Harbin, Heilongjiang, 150001, China.
authors.forename: Anqi
authors.initials: A
authors.lastname: Wu
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Harbin Medical University, No 23 Youzheng St., Nangang District, Harbin, Heilongjiang, 150001, China.
authors.forename: Hongshuang
authors.initials: H
authors.lastname: Tong
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Harbin Medical University, No 23 Youzheng St., Nangang District, Harbin, Heilongjiang, 150001, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Harbin Medical University, No 23 Youzheng St., Nangang District, Harbin, Heilongjiang, 150001, China. changsongwang@aliyun.com.
authors.forename: Changsong
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Harbin Medical University, No 23 Youzheng St., Nangang District, Harbin, Heilongjiang, 150001, China. enyouli@aliyun.com.
authors.forename: Enyou
authors.initials: E
authors.lastname: Li
mesh_terms: D055371:Acute Lung Injury / Q000517:prevention & control*; D001499:Bayes Theorem; D006801:Humans; D007362:Intensive Care Units / Q000458:organization & administration / Q000706:statistics & numerical data; D008170:Lung Compliance / Q000502:physiology; D011175:Positive-Pressure Respiration / Q000379:methods / Q000401:mortality; D012121:Respiration, Artificial / Q000145:classification* / Q000379:methods*; D016019:Survival Analysis; D013990:Tidal Volume / Q000502:physiology
keywords: ICU patients without ALI or ARDS; Network meta-analysis; PaO2/FIO2 ratio; Pulmonary compliance; Ventilation strategies