title: Comparison of prone positioning and high-frequency oscillatory ventilation in patients with acute respiratory distress syndrome.
abstract: OBJECTIVE
  Both prone position and high-frequency oscillatory ventilation (HFOV) have the potential to facilitate lung recruitment, and their combined use could thus be synergetic on gas exchange. Keeping the lung open could also potentially be lung protective. The aim of this study was to compare physiologic and proinflammatory effects of HFOV, prone positioning, or their combination in severe acute respiratory distress syndrome (ARDS).
  
  
  METHODS
  : Prospective, comparative randomized study.
  
  
  METHODS
  A medical intensive care unit.
  
  
  METHODS
  Thirty-nine ARDS patients with a Pao2/Fio2 ratio <150 mm Hg at positive end-expiratory pressure > or =5 cm H2O.
  
  
  METHODS
  After 12 hrs on conventional lung-protective mechanical ventilation (tidal volume 6 mL/kg of ideal body weight, plateau pressure not exceeding the upper inflection point, and a maximum of 35 cm H2O; supine-CV), 39 patients were randomized to receive one of the following 12-hr periods: conventional lung-protective mechanical ventilation in prone position (prone-CV), HFOV in supine position (supine-HFOV), or HFOV in prone position (prone-HFOV).
  
  
  RESULTS
  Prone-CV (from 138 +/- 58 mm Hg to 217 +/- 110 mm Hg, p < .0001) and prone-HFOV (from 126 +/- 40 mm Hg to 227 +/- 64 mm Hg, p < 0.0001) improved the Pao2/Fio2 ratio whereas supine-HFOV did not alter the Pao2/Fio2 ratio (from 134 +/- 57 mm Hg to 138 +/- 48 mm Hg). The oxygenation index ({mean airway pressure x Fio2 x 100}/Pao2) decreased in the prone-CV and prone-HFOV groups and was lower than in the supine-HFOV group. Interleukin-8 increased significantly in the bronchoalveolar lavage fluid (BALF) in supine-HFOV and prone-HFOV groups compared with prone-CV and supine-CV. Neutrophil counts were higher in the supine-HFOV group than in the prone-CV group.
  
  
  CONCLUSIONS
  Although HFOV in the supine position does not improve oxygenation or lung inflammation, the prone position increases oxygenation and reduces lung inflammation in ARDS patients. Prone-HFOV produced similar improvement in oxygenation like prone-CV but was associated with higher BALF indexes of inflammation. In contrast, supine-HFOV did not improve gas exchange and was associated with enhanced lung inflammation.
authors.affiliation: Service de Réanimation Médicale, Hôpital Sainte-Marguerite, Faculté de Médecine de Marseille, Université de la Méditerranée, Marseille, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Papazian
authors.forename: Marc
authors.initials: M
authors.lastname: Gainnier
authors.forename: Valérie
authors.initials: V
authors.lastname: Marin
authors.forename: Stéphane
authors.initials: S
authors.lastname: Donati
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Arnal
authors.forename: Didier
authors.initials: D
authors.lastname: Demory
authors.forename: Antoine
authors.initials: A
authors.lastname: Roch
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Forel
authors.forename: Pierre
authors.initials: P
authors.lastname: Bongrand
authors.forename: Fabienne
authors.initials: F
authors.lastname: Brégeon
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Sainty
mesh_terms: D000328:Adult; D001784:Blood Gas Analysis; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D005260:Female; D006612:High-Frequency Ventilation; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D016684:Prone Position; D011446:Prospective Studies; D011659:Pulmonary Gas Exchange / Q000502:physiology*; D012128:Respiratory Distress Syndrome / Q000378:metabolism / Q000503:physiopathology* / Q000628:therapy*; D015656:Respiratory Mechanics; D016683:Supine Position
chemical_list: D018836:Inflammation Mediators