title: Influence of intraoperative positive end-expiratory pressure level on pulmonary complications in emergency major trauma surgery.
abstract: BACKGROUND
  Pulmonary complications have a major impact on the morbidity and mortality of critically ill patients with multiple trauma. Intraoperative protective ventilation with low tidal volume may prevent lung injury and infection, whereas the role of positive end-expiratory pressure (PEEP) levels is unclear. The aim of this study was to evaluate the influence of different intraoperative PEEP levels on incidence of pulmonary complications after emergency trauma surgery.
  
  
  METHODS
  We retrospectively analysed data of multiple trauma patients who underwent emergency surgery within 24 h after injury in our level I trauma centre (n= 86). On the basis of their intraoperative PEEP level, patients were divided into a low PEEP group with a PEEP of < 8 mbar and a high PEEP group with a PEEP of 8 mbar or higher.
  
  
  RESULTS
  Besides differences in body mass index and preoperative oxygenation, there were no differences in patients' baseline data. There was a significant difference between incidence of pneumonia within 7 days after trauma surgery, with an incidence 26.7% in the low PEEP group and 7.3% in the high PEEP group (p= 0.02). The low PEEP group had higher pulmonary infection scores at days 3 and 5 after surgery. Oxygenation was better in the higher PEEP group postoperatively. There was no difference with respect to the incidence of acute respiratory distress syndrome, the mortality up until hospital discharge or haemodynamic parameters between groups.
  
  
  CONCLUSIONS
  Higher PEEP levels were associated with perioperative improvement of oxygenation and a lower incidence of pneumonia, without impairment of haemodynamics. Additional studies should be initiated to confirm these observations.
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, Hannover Medical School, Hannover, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Stueber
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, Hannover Medical School, Hannover, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Karsten
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, Hannover Medical School, Hannover, Germany.
authors.forename: Nikolas
authors.initials: N
authors.lastname: Voigt
authors.affiliation: Trauma Department, Hannover Medical School, Hannover, Germany.
authors.forename: Michaela
authors.initials: M
authors.lastname: Wilhelmi
keywords: intraoperative ventilation; multiple trauma; pneumonia