title: Intraoperative protective mechanical ventilation and risk of postoperative respiratory complications: hospital based registry study.
abstract: OBJECTIVE
  To evaluate the effects of intraoperative protective ventilation on major postoperative respiratory complications and to define safe intraoperative mechanical ventilator settings that do not translate into an increased risk of postoperative respiratory complications.
  
  
  METHODS
  Hospital based registry study.
  
  
  METHODS
  Academic tertiary care hospital and two affiliated community hospitals in Massachusetts, United States.
  
  
  METHODS
  69,265 consecutively enrolled patients over the age of 18 who underwent a non-cardiac surgical procedure between January 2007 and August 2014 and required general anesthesia with endotracheal intubation.
  
  
  METHODS
  Protective ventilation, defined as a median positive end expiratory pressure (PEEP) of 5 cmH2O or more, a median tidal volume of less than 10 mL/kg of predicted body weight, and a median plateau pressure of less than 30 cmH2O.
  
  
  METHODS
  Composite outcome of major respiratory complications, including pulmonary edema, respiratory failure, pneumonia, and re-intubation.
  
  
  RESULTS
  Of the 69,265 enrolled patients 34,800 (50.2%) received protective ventilation and 34,465 (49.8%) received non-protective ventilation intraoperatively. Protective ventilation was associated with a decreased risk of postoperative respiratory complications in multivariable regression (adjusted odds ratio 0.90, 95% confidence interval 0.82 to 0.98, P=0.013). The results were similar in the propensity score matched cohort (odds ratio 0.89, 95% confidence interval 0.83 to 0.97, P=0.004). A PEEP of 5 cmH2O and median plateau pressures of 16 cmH2O or less were associated with the lowest risk of postoperative respiratory complications.
  
  
  CONCLUSIONS
  Intraoperative protective ventilation was associated with a decreased risk of postoperative respiratory complications. A PEEP of 5 cmH2O and a plateau pressure of 16 cmH2O or less were identified as protective mechanical ventilator settings. These findings suggest that protective thresholds differ for intraoperative ventilation in patients with normal lungs compared with those used for patients with acute lung injury.
authors.affiliation: Department of Anesthesia, Critical Care, Pain Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.
authors.forename: Karim
authors.initials: K
authors.lastname: Ladha
authors.affiliation: Department of Anesthesia, Critical Care, Pain Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.
authors.forename: Marcos F
authors.initials: MF
authors.lastname: Vidal Melo
authors.affiliation: Department of Anesthesia, Critical Care, Pain Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.
authors.forename: Duncan J
authors.initials: DJ
authors.lastname: McLean
authors.affiliation: Department of Anesthesiology, Vanderbilt University, Nashville, TN, USA.
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Wanderer
authors.affiliation: Department of Anesthesia, Critical Care, Pain Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.
authors.forename: Stephanie D
authors.initials: SD
authors.lastname: Grabitz
authors.affiliation: INSERM Research Center for Epidemiology and Biostatistics (U897)-Team Neuroepidemiology, Bordeaux, France College of Health Sciences, University of Bordeaux, Bordeaux, France Division of Preventive Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Tobias
authors.initials: T
authors.lastname: Kurth
authors.affiliation: Department of Anesthesia, Critical Care, Pain Medicine, Massachusetts General Hospital, Boston, MA 02114, USA Essen-Duisburg University, Essen, Germany meikermann@partners.org.
authors.forename: Matthias
authors.initials: M
authors.lastname: Eikermann
mesh_terms: D000768:Anesthesia, General; D002985:Clinical Protocols; D045422:Continuous Positive Airway Pressure; D006801:Humans; D007902:Length of Stay; D008404:Massachusetts; D011175:Positive-Pressure Respiration; D012042:Registries; D012128:Respiratory Distress Syndrome / Q000517:prevention & control*; D012307:Risk Factors; D013990:Tidal Volume; D013997:Time Factors