title: High-frequency oscillatory ventilation following prone positioning prevents a further impairment in oxygenation.
abstract: OBJECTIVE
  The improvement in oxygenation with prone positioning is not persistent when patients with acute respiratory distress syndrome (ARDS) are turned supine. High-frequency oscillatory ventilation (HFOV) aims to maintain an open lung volume by the application of a constant mean airway pressure. The aim of this study was to show that HFOV is able to prevent the impairment in oxygenation when ARDS patients are turned back from the prone to the supine position.
  
  
  METHODS
  Prospective, comparative randomized study.
  
  
  METHODS
  A medical intensive care unit.
  
  
  METHODS
  Forty-three ARDS patients with a Pao2/Fio2 ratio <150 at positive end-expiratory pressure > or =5 cm H2O.
  
  
  METHODS
  After an optimization period, the patients were assigned to one of three groups: a) conventional lung-protective mechanical ventilation in the prone position (12 hrs) followed by a 12-hr period of conventional lung-protective mechanical ventilation in the supine position (CV(prone)-CV(supine)); b) conventional lung-protective mechanical ventilation in the supine position (12 hrs) followed by HFOV in the supine position (12 hrs) (CV(supine)-HFOV(supine)); or c) conventional lung-protective mechanical ventilation in the prone position (12 hrs) followed by HFOV in the supine position (CV(prone)-HFOV(supine) group).
  
  
  RESULTS
  Pao2/Fio2 ratio was higher at the end of the study period in the CV(prone)-HFOV(supine) group than in the CV(prone)-CV(supine) group (p < .02). Venous admixture at the end of the study period was lower in the CV(prone)-HFOV(supine) group than in the two other groups.
  
  
  CONCLUSIONS
  HFOV maintained the improvement in oxygenation related to prone positioning when ARDS patients were returned to the supine position.
authors.affiliation: Service de Réanimation Médicale, Hôpital Sainte-Marguerite, Université de la Méditerranée, Marseille, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Demory
authors.forename: Pierre
authors.initials: P
authors.lastname: Michelet
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Arnal
authors.forename: Stéphane
authors.initials: S
authors.lastname: Donati
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Forel
authors.forename: Marc
authors.initials: M
authors.lastname: Gainnier
authors.forename: Fabienne
authors.initials: F
authors.lastname: Brégeon
authors.forename: Laurent
authors.initials: L
authors.lastname: Papazian
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D001784:Blood Gas Analysis; D003422:Critical Care / Q000379:methods; D005260:Female; D005602:France; D006612:High-Frequency Ventilation / Q000379:methods*; D006785:Hospitals, University; D006801:Humans; D008297:Male; D008875:Middle Aged; D016684:Prone Position; D011446:Prospective Studies; D011659:Pulmonary Gas Exchange; D012121:Respiration, Artificial / Q000379:methods; D012128:Respiratory Distress Syndrome / Q000175:diagnosis / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy*; D016683:Supine Position; D013990:Tidal Volume; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome