title: Constant vs auto-continuous positive airway pressure in patients with sleep apnea hypopnea syndrome and a high variability in pressure requirement.
abstract: OBJECTIVE
  Auto-continuous positive airway pressure (CPAP) has been reported to have no more efficacy than constant CPAP in unselected patients with sleep apnea hypopnea syndrome (SAHS). The aim of this study was to evaluate patients judged to be good candidates for auto-CPAP because of a high within-night variability in pressure requirement.
  
  
  METHODS
  Single-blind, randomized, cross-over study (2 x 8 weeks) to compare auto-CPAP with constant CPAP.
  
  
  METHODS
  Outpatients with moderate-to-severe SAHS attending the chest clinic.
  
  
  METHODS
  Patients were equipped at home in the auto-CPAP mode (model GK418A; Malinckrodt; Nancy, France), using a 4- to 14-cm H(2)O pressure range. Those individuals having a high within-night variability in pressure requirement, assessed at the end of a 14-day run-in period, were included in the cross-over study. Auto-CPAP was compared with constant CPAP (according to a titration night in the sleep laboratory) in terms of compliance, efficacy on apneas (assessed from the pressure monitor), and sleepiness (assessed on the Epworth sleepiness scale).
  
  
  RESULTS
  Of 90 consecutive patients with SAHS, 27 patients were selected for a within-night variability in pressure requirement exceeding a given threshold. After completion of the cross-over, 24 patients were evaluable. The median percentage of nights the machine was used was 95.5% (range, 45 to 100%) on constant CPAP, and 96.5% (range, 40 to 100%) on auto-CPAP; the median apnea index recorded by the device was 0.40/h (range, 0 to 2.40/h) on constant CPAP, and 0.45/h (range, 0 to 5.80/h) on auto-CPAP (differences not significant). The mean Epworth sleepiness score was significantly (p < 0.01) lower on auto-CPAP (5.1; SD, 2.8) than on constant CPAP (6.1; SD, 2.8).
  
  
  CONCLUSIONS
  In patients selected for a high within-night variability in pressure requirement, auto-CPAP administered via a GK418A device was equivalent to constant CPAP based on a titration night in the sleep laboratory. Subjective ratings for sleepiness were slightly lower on auto-CPAP.
authors.affiliation: Chest Department and Sleep Laboratory, Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium. andre.noseda@chu-brugmann.be
authors.forename: André
authors.initials: A
authors.lastname: Noseda
authors.forename: Chantal
authors.initials: C
authors.lastname: Kempenaers
authors.forename: Myriam
authors.initials: M
authors.lastname: Kerkhofs
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Braun
authors.forename: Paul
authors.initials: P
authors.lastname: Linkowski
authors.forename: Ernest
authors.initials: E
authors.lastname: Jann
mesh_terms: D045422:Continuous Positive Airway Pressure / Q000379:methods*; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016037:Single-Blind Method; D012891:Sleep Apnea Syndromes / Q000628:therapy*; D011795:Surveys and Questionnaires