title: Mechanical ventilation strategies for the surgical patient.
abstract: OBJECTIVE
  To summarize clinical evidence for intraoperative ventilation settings, which could protect against postoperative pulmonary complications (PPCs) in surgical patients with uninjured lungs.
  
  
  RESULTS
  There is convincing evidence for protection against PPCs by low tidal volumes: benefit was found in several randomized controlled trials, and was recently confirmed in meta-analyses. Evidence for protection against PPCs by high levels of positive end-expiratory pressure (PEEP) is less definite. Although benefit was found in several randomized controlled trials, most of them compared a bundle of low tidal volume and high level of PEEP with conventional ventilation; one recent large randomized controlled trial that compared high with low levels of PEEP showed that ventilation with high level of PEEP did not protect against PPCs but caused intraoperative complications instead. A recent individual patient data meta-analysis of trials comparing bundles of low tidal volume and high levels of PEEP to conventional intraoperative ventilation suggested that protection against PPCs comes from tidal volume reductions, and not from increasing levels of PEEP.
  
  
  CONCLUSIONS
  The understanding on the protective roles of tidal volume and PEEP settings against PPCs has rapidly expanded. During intraoperative ventilation, low tidal volumes are protective, the protective role of high levels of PEEP is uncertain.
authors.affiliation: aDepartment of Intensive Care bLaboratory of Experimental Intensive Care and Anesthesiology (L·E·I·C·A), Academic Medical Center at the University of Amsterdam, Amsterdam, The Netherlands cPulmonary Engineering Group, Department of Anesthesiology and Intensive Care Medicine, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany dDepartment of Surgical Sciences and Integrated Diagnostics, IRCCS AOU San Martino IST, University of Genoa, Genoa, Italy.
authors.forename: Marcus J
authors.initials: MJ
authors.lastname: Schultz
authors.forename: Marcelo Gama de
authors.initials: MG
authors.lastname: Abreu
authors.forename: Paolo
authors.initials: P
authors.lastname: Pelosi
mesh_terms: D003422:Critical Care; D006801:Humans; D007430:Intraoperative Care; D055370:Lung Injury / Q000517:prevention & control; D011175:Positive-Pressure Respiration / Q000009:adverse effects; D011183:Postoperative Complications / Q000517:prevention & control; D016032:Randomized Controlled Trials as Topic; D012121:Respiration, Artificial; D013990:Tidal Volume / Q000502:physiology*