title: Is the supine position associated with loss of airway patency in unconscious trauma patients? A systematic review and meta-analysis.
abstract: BACKGROUND
  Airway compromise is a leading cause of death in unconscious trauma patients. Although endotracheal intubation is regarded as the gold standard treatment, most prehospital providers are not trained to perform ETI in such patients. Therefore, various lateral positions are advocated for unconscious patients, but their use remains controversial in trauma patients. We conducted a systematic review to investigate whether the supine position is associated with loss of airway patency compared to the lateral position.
  
  
  METHODS
  The review protocol was published in the PROSPERO database (Reg. no. CRD42012001190). We performed literature searches in PubMed, Medline, EMBASE, Cochrane Library, CINAHL and British Nursing Index and included studies related to airway patency, reduced level of consciousness and patient position. We conducted meta-analyses, where appropriate. We graded the quality of evidence with the GRADE methodology. The search was updated in June 2014.
  
  
  RESULTS
  We identified 1,306 publications, 39 of which were included for further analysis. Sixteen of these publications were included in meta-analysis. We did not identify any studies reporting direct outcome measures (mortality or morbidity) related to airway compromise caused by the patient position (lateral vs. supine position) in trauma patients or in any other patient group. In studies reporting only indirect outcome measures, we found moderate evidence of reduced airway patency in the supine vs. the lateral position, which was measured by the apnea/hypopnea index (AHI). For other indirect outcomes, we only found low or very low quality evidence.
  
  
  CONCLUSIONS
  Although concerns other than airway patency may influence how a trauma patient is positioned, our systematic review provides evidence supporting the long held recommendation that unconscious trauma patients should be placed in a lateral position.
authors.affiliation: Department of Research and Development, Norwegian Air Ambulance Foundation, Drøbak, Norway. pkh@sshf.no.|Department of Anesthesiology and Intensive Care Medicine, Sørlandet Hospital, Kristiansand, Norway. pkh@sshf.no.
authors.forename: Per Kristian
authors.initials: PK
authors.lastname: Hyldmo
authors.affiliation: The Norwegian Knowledge Center for the Health Services, Oslo, Norway. gunn.vist@kunnskapssenteret.no.
authors.forename: Gunn E
authors.initials: GE
authors.lastname: Vist
authors.affiliation: Department of Anesthesiology, Oslo University Hospital, Oslo, Norway. anders.feyling@gmail.com.
authors.forename: Anders Christian
authors.initials: AC
authors.lastname: Feyling
authors.affiliation: Pre-hospital Critical Care Services, Aarhus, Denmark. leifrogn@rm.dk.
authors.forename: Leif
authors.initials: L
authors.lastname: Rognås
authors.affiliation: Department of Anesthesiology, Landspitalinn University Hospital, Reykjavík, Iceland. vidar.magnusson@gmail.com.
authors.forename: Vidar
authors.initials: V
authors.lastname: Magnusson
authors.affiliation: Faculty of Medicine, University of Oslo, Oslo, Norway. marten.sandberg@medisin.uio.no.|Air Ambulance Department, Oslo University Hospital, Oslo, Norway. marten.sandberg@medisin.uio.no.
authors.forename: Mårten
authors.initials: M
authors.lastname: Sandberg
authors.affiliation: Network for Medical Sciences, University of Stavanger, Stavanger, Norway. eldar.soreide@sus.no.|Department of Anesthesiology and Intensive Care Medicine, University Hospital of Stavanger, Stavanger, Norway. eldar.soreide@sus.no.
authors.forename: Eldar
authors.initials: E
authors.lastname: Søreide
mesh_terms: D000402:Airway Obstruction / Q000209:etiology* / Q000628:therapy; D006801:Humans; D007442:Intubation, Intratracheal / Q000379:methods*; D056888:Patient Positioning / Q000009:adverse effects*; D016683:Supine Position; D014474:Unconsciousness / Q000628:therapy*