title: Short-term effects of combining upright and prone positions in patients with ARDS: a prospective randomized study.
abstract: BACKGROUND
  Prone position is known to improve oxygenation in patients with acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS). Supine upright (semirecumbent) position also exerts beneficial effects on gas exchange in this group of patients. We evaluated the effect of combining upright and prone position on oxygenation and respiratory mechanics in patients with ALI or ARDS in a prospective randomized cross-over study.
  
  
  METHODS
  After turning them prone from a supine position, we randomized the patients to a prone position or combined prone and upright position. After 2 hours, the position was changed to the other one for another 6 hours. The gas exchange and static compliance of the respiratory system, lungs, and chest wall were assessed in the supine position as well as every hour in the prone position.
  
  
  RESULTS
  Twenty patients were enrolled in the study. The PaO₂/FiO₂ ratio improved significantly from the supine to the prone position and further significantly increased with additional upright position. Fourteen (70%) patients were classified as responders to the prone position, whereas 17 (85%) patients responded to the prone plus upright position compared with the supine position (P = n.s.). No statistically significant changes were found with respect to compliance.
  
  
  CONCLUSIONS
  Combining the prone position with the upright position in patients with ALI or ARDS leads to further improvement of oxygenation.
  
  
  BACKGROUND
  Clinical Trials No. NCT00753129.
authors.affiliation: Department of Internal Medicine I, Intensive Care Unit, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria.
authors.forename: Oliver
authors.initials: O
authors.lastname: Robak
authors.forename: Peter
authors.initials: P
authors.lastname: Schellongowski
authors.forename: Andja
authors.initials: A
authors.lastname: Bojic
authors.forename: Klaus
authors.initials: K
authors.lastname: Laczika
authors.forename: Gottfried J
authors.initials: GJ
authors.lastname: Locker
authors.forename: Thomas
authors.initials: T
authors.lastname: Staudinger
mesh_terms: D055371:Acute Lung Injury / Q000503:physiopathology / Q000628:therapy*; D000368:Aged; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood*; D056888:Patient Positioning / Q000379:methods*; D016684:Prone Position / Q000502:physiology*; D011446:Prospective Studies; D012128:Respiratory Distress Syndrome / Q000503:physiopathology / Q000628:therapy*; D015656:Respiratory Mechanics / Q000502:physiology*; D016683:Supine Position / Q000502:physiology*
chemical_list: D010100:Oxygen