title: Is a short trial of prone positioning sufficient to predict the improvement in oxygenation in patients with acute respiratory distress syndrome?
abstract: OBJECTIVE
  To determine whether a 1-h trial of prone positioning is sufficient to identify responders.
  
  
  METHODS
  Prospective clinical cohort study in a medico-surgical ICU in a teaching hospital.
  
  
  METHODS
  49 patients with acute respiratory distress syndrome.
  
  
  METHODS
  A 6-h period of prone positioning.
  
  
  RESULTS
  Baseline measurements (blood gas analysis and respiratory parameters) were evaluated in supine position just prior to turning the patients prone. Measurements were then repeated 1 h after the beginning of prone positioning (PP1h) and at the end of the 6-h period of prone positioning (PP6h). The last measurements were performed 1 h after repositioning the patients supine. Prone position induced an increase in the PaO2/FIO2 ratio (p < 0.001). A response (increase in PaO2/FIO2 ratio of at least 20 % at PP1h and/or at PP6h) was observed in 37 of 49 patients (76%). Twenty-seven of these patients (73%) were responders at PP1h while 10 (27%) were responders only at PP6h- In all, two-thirds of the patients were considered persistent responders. However, whereas the PaO2/FIO2 ratio decreased significantly 1 h after repositioning the fast responders supine, the PaO2/ FIO2 ratio remained unchanged after repositioning slow responders.
  
  
  CONCLUSIONS
  A short-term trial of prone positioning does not appear a sufficient method to identify patients who would benefit from the postural treatment.
authors.affiliation: Service de Réanimation Médicale, Hĵpitaux Sud, Marseille, France. lpapazian@mail.ap-hm.fr
authors.forename: L
authors.initials: L
authors.lastname: Papazian
authors.forename: M H
authors.initials: MH
authors.lastname: Paladini
authors.forename: F
authors.initials: F
authors.lastname: Bregeon
authors.forename: L
authors.initials: L
authors.lastname: Huiart
authors.forename: X
authors.initials: X
authors.lastname: Thirion
authors.forename: P
authors.initials: P
authors.lastname: Saux
authors.forename: Y
authors.initials: Y
authors.lastname: Jammes
authors.forename: J P
authors.initials: JP
authors.lastname: Auffray
mesh_terms: D018806:APACHE; D001784:Blood Gas Analysis; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D011175:Positive-Pressure Respiration; D011237:Predictive Value of Tests; D016684:Prone Position; D011446:Prospective Studies; D012119:Respiration; D012128:Respiratory Distress Syndrome / Q000145:classification / Q000628:therapy*; D013997:Time Factors