title: Pressure reduction during exhalation in sleep apnea patients treated by continuous positive airway pressure.
abstract: BACKGROUND
  This French, multicenter, randomized double-blind controlled trial tested the hypothesis that pressure reduction during exhalation (C-Flex; Respironics; Murrysville, PA) would improve continuous positive airway pressure (CPAP) compliance, comfort, and quality of life.
  
  
  METHODS
  Two hundred eighteen newly diagnosed sleep apnea patients (seven centers; mean [+/- SD] age, 55 +/- 11 years; mean body mass index, 31 +/- 6 kg/m(2); mean apnea-hypopnea index, 44 +/- 21 events/h) were randomly assigned to receive 3 months of treatment with CPAP (108 patients) or C-Flex (110 patients). Objective compliance, generic quality-of-life questionnaire (SF-36) scores, disease-specific quality-of-life questionnaire (Grenoble Sleep Apnea Quality of Life [GrenobleSAQOL]) scores, and visual analog scales for CPAP comfort and side effects were determined at baseline and after 3 months. After 3 months, patients in the CPAP arm were moved to the C-Flex arm for 3 additional months (open study).
  
  
  RESULTS
  An intention-to-treat analysis demonstrated that there were no differences at 3 months between C-Flex and CPAP use in terms of compliance, the rate of side effects, and comfort. Low compliers receiving CPAP therapy (< 4 h of use) significantly improved this outcome during the open study (p = 0.04). There was a significant improvement in six of eight of the SF-36 domain scores and in all of the domains of the GrenobleSAQOL scores in both groups using either CPAP or C-Flex.
  
  
  CONCLUSIONS
  In unselected sleep apnea patients, C-Flex was associated with similar outcomes to standard CPAP. Low compliers receiving CPAP therapy improved their adherence when moving to C-Flex.
  
  
  BACKGROUND
  ISRCTN Register Identifier: 08065291.
authors: HP2 Laboratory, Institut National de la Santé et de la Recherche Médicale (INSERM), Equipe Région INSERM 17, Grenoble University Hospital, Grenoble, France. Electronic address: JPepin@chu-grenoble.fr.
authors: Jean-Louis
authors: JL
authors: Pépin
authors: Service de Pneumologie, Hôpital Boisguillaume, Rouen, France.
authors: Jean-François
authors: JF
authors: Muir
authors: Clinique de La Louvière, Lille, France.
authors: Thibaut
authors: T
authors: Gentina
authors: University Hospital of Montpellier, Montpellier, France.
authors: Yves
authors: Y
authors: Dauvilliers
authors: HP2 Laboratory, Institut National de la Santé et de la Recherche Médicale (INSERM), Equipe Région INSERM 17, Grenoble University Hospital, Grenoble, France.
authors: Renaud
authors: R
authors: Tamisier
authors: Polyclinique de Bordeaux, Bordeaux, France.
authors: Marc
authors: M
authors: Sapene
authors: Service de Physiologie-Explorations Fonctionnelles, Hôpital A. Béclère, Assistance Publique-Hôpitaux de Paris, Clamart, France.
authors: Pierre
authors: P
authors: Escourrou
authors: Service de Pneumologie, Hôpital St Antoine, Assistance Publique-Hôpitaux de Paris, Paris, France.
authors: Bernard
authors: B
authors: Fleury
authors: Service de Pneumologie, Hôpital St Joseph, Assistance Publique-Hôpitaux de Marseille, Marseille, France.
authors: François
authors: F
authors: Philip-Joet
authors: Service de Physiologie-Explorations Fonctionnelles, Hôpital Pellegrin, Bordeaux, France.
authors: Pierre
authors: P
authors: Philip
authors: Groupe Henri-Mondor Albert Chennevier, Service de Physiologie-Explorations Fonctionnelles, Assistance Publique-Hôpitaux de Paris, Créteil, France; Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 841, Créteil, F-94010 France; Université Paris-7-Denis Diderot, Faculté de Médecine Xavier Bichat, Paris, France.
authors: Marie-Pia
authors: MP
authors: d'Ortho
mesh_terms: D000328:Adult; D000399:Air Pressure; D015992:Body Mass Index; D045422:Continuous Positive Airway Pressure / Q000379:methods*; D004311:Double-Blind Method; D045853:Exhalation / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance / Q000706:statistics & numerical data; D017286:Polysomnography; D011788:Quality of Life; D012016:Reference Values; D018570:Risk Assessment; D012720:Severity of Illness Index; D012891:Sleep Apnea Syndromes / Q000175:diagnosis / Q000628:therapy*; D018709:Statistics, Nonparametric; D013997:Time Factors; D016896:Treatment Outcome