title: Association between tidal volume size, duration of ventilation, and sedation needs in patients without acute respiratory distress syndrome: an individual patient data meta-analysis.
abstract: OBJECTIVE
  Mechanical ventilation with lower tidal volumes (≤6 ml/kg of predicted body weight, PBW) could benefit patients without acute respiratory distress syndrome (ARDS). However, tidal volume reduction could be associated with increased patient discomfort and sedation needs, and consequent longer duration of ventilation. The aim of this individual patient data meta-analysis was to assess the associations between tidal volume size, duration of mechanical ventilation, and sedation needs in patients without ARDS.
  
  
  METHODS
  Studies comparing ventilation with different tidal volume sizes in patients without ARDS were screened for inclusion. Corresponding authors were asked to provide individual participant data. Patients were assigned to three groups based on tidal volume size (≤6 ml/kg PBW, 6-10 ml/kg PBW, or ≥10 ml/kg PBW). Ventilator-free days, alive at day 28, and dose and duration of sedation (propofol and midazolam), analgesia (fentanyl and morphine), and neuromuscular blockade (NMB) were compared.
  
  
  RESULTS
  Seven investigations (2,184 patients) were included in the analysis. The number of patients breathing without assistance by day 28 was higher in the group ventilated with tidal volume ≤6 ml/kg PBW compared to those ventilated with tidal volume ≥10 ml/kg PBW (93.1 vs. 88.6%; p = 0.027, respectively). Only two investigations (187 patients) could be included in the meta-analysis of sedation needs. There were neither differences in the percentage of study days that patients received sedatives, opioids, or NMBA nor in the total dose of benzodiazepines, propofol, opioids, and NMBA.
  
  
  CONCLUSIONS
  This meta-analysis suggests that use of lower tidal volumes in patients without ARDS at the onset of mechanical ventilation could be associated with shorter duration of ventilation. Use of lower tidal volumes seems not to affect sedation or analgesia needs, but this must be confirmed in a robust, well-powered randomized controlled trial.
authors.affiliation: Department of Intensive Care, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands, aryserpa@terra.com.br.
authors.forename: Ary
authors.initials: A
authors.lastname: Serpa Neto
authors.forename: Fabienne D
authors.initials: FD
authors.lastname: Simonis
authors.forename: Carmen S V
authors.initials: CS
authors.lastname: Barbas
authors.forename: Michelle
authors.initials: M
authors.lastname: Biehl
authors.forename: Rogier M
authors.initials: RM
authors.lastname: Determann
authors.forename: Jonathan
authors.initials: J
authors.lastname: Elmer
authors.forename: Gilberto
authors.initials: G
authors.lastname: Friedman
authors.forename: Ognjen
authors.initials: O
authors.lastname: Gajic
authors.forename: Joshua N
authors.initials: JN
authors.lastname: Goldstein
authors.forename: Janneke
authors.initials: J
authors.lastname: Horn
authors.forename: Nicole P
authors.initials: NP
authors.lastname: Juffermans
authors.forename: Rita
authors.initials: R
authors.lastname: Linko
authors.forename: Roselaine Pinheiro
authors.initials: RP
authors.lastname: de Oliveira
authors.forename: Sugantha
authors.initials: S
authors.lastname: Sundar
authors.forename: Daniel
authors.initials: D
authors.lastname: Talmor
authors.forename: Esther K
authors.initials: EK
authors.lastname: Wolthuis
authors.forename: Marcelo Gama
authors.initials: MG
authors.lastname: de Abreu
authors.forename: Paolo
authors.initials: P
authors.lastname: Pelosi
authors.forename: Marcus J
authors.initials: MJ
authors.lastname: Schultz
mesh_terms: D000701:Analgesics, Opioid / Q000008:administration & dosage; D005283:Fentanyl / Q000008:administration & dosage; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage*; D007362:Intensive Care Units; D007902:Length of Stay / Q000706:statistics & numerical data; D008874:Midazolam / Q000008:administration & dosage; D009020:Morphine / Q000008:administration & dosage; D019148:Neuromuscular Blockade / Q000706:statistics & numerical data; D015742:Propofol / Q000008:administration & dosage; D012121:Respiration, Artificial / Q000379:methods* / Q000706:statistics & numerical data; D013990:Tidal Volume; D013997:Time Factors
chemical_list: D000701:Analgesics, Opioid; D006993:Hypnotics and Sedatives; D009020:Morphine; D008874:Midazolam; D005283:Fentanyl; D015742:Propofol