title: Titration efficacy of two auto-adjustable continuous positive airway pressure devices using different flow limitation-based algorithms.
abstract: BACKGROUND
  Auto-adjustable continuous positive airway pressure devices are widely used in titration procedures to determine therapeutic pressure levels in obstructive sleep apnea patients. However, differences in operational characteristics may influence the effect on the apnea-hypopnea index (AHI).
  
  
  OBJECTIVE
  We compared the titration performance of two devices based on detection of inspiratory flow limitation, i.e. the Respironics REMstar Auto (RR) and the ResMed Spirit (RS).
  
  
  METHODS
  Fifty obstructive sleep apnea patients were recruited for a double-blind randomized crossover trial. Both devices were employed overnight by means of split-night polysomnography. The primary outcome was the AHI. Secondary outcome measures were the snoring index, pressure profiles and subjective appraisal of sleep quality assessed the morning after the sleep study. The Wilcoxon signed rank test for matched pairs was applied to assess differences between treatment conditions.
  
  
  RESULTS
  No significant differences were found in sleep parameters, subjective sleep quality and snoring index. The use of the RR was associated with a significantly lower AHI in comparison with the RS [mean (SD) 6.9 (11.6)/h vs. 9.4 (9.2)/h, p = 0.004]. This result was obtained at significantly lower pressure levels [P95 9.2 (2.3) cm H(2)O vs. 10.2 (1.5) cm H(2)O, p = 0.001].
  
  
  CONCLUSIONS
  While the RR provided a lower AHI than the RS at lower pressure levels, it could not be assessed whether this difference was relevant for clinical outcomes. However, this face-to-face comparison of Auto-adjustable continuous positive airway pressure devices seems useful for the assessment of titration efficacy.
authors.affiliation: Department of Respiratory Diseases, Ghent University Hospital, Ghent, Belgium. Katrien.Hertegonne@UGent.be
authors.forename: Katrien B
authors.initials: KB
authors.lastname: Hertegonne
authors.forename: Bart
authors.initials: B
authors.lastname: Rombaut
authors.forename: Philippe
authors.initials: P
authors.lastname: Houtmeyers
authors.forename: Georges
authors.initials: G
authors.lastname: Van Maele
authors.forename: Dirk A
authors.initials: DA
authors.lastname: Pevernagie
mesh_terms: D000328:Adult; D000403:Airway Resistance; D000704:Analysis of Variance; D001331:Automation; D001784:Blood Gas Analysis; D045422:Continuous Positive Airway Pressure / Q000295:instrumentation* / Q000379:methods; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology*; D017286:Polysomnography; D011336:Probability; D011659:Pulmonary Gas Exchange; D018570:Risk Assessment; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000628:therapy*; D018709:Statistics, Nonparametric; D017186:Titrimetry; D016896:Treatment Outcome; D012122:Ventilators, Mechanical / Q000592:standards*