title: Effective comparison of two auto-CPAP devices for treatment of obstructive sleep apnea based on polysomnographic evaluation.
abstract: BACKGROUND
  Automatic continuous positive airway pressure (auto-CPAP) machines differ mainly in algorithms used for respiratory event detection and pressure control. The auto-CPAP machines operated by novel algorithms are expected to have better performance than the earlier ones in the treatment of obstructive sleep apnea syndrome (OSAS).
  
  
  OBJECTIVE
  The purpose of this study was to determine the therapeutic characteristics between two different auto-CPAP devices, i.e., the third-generation flow-based (f-APAP) and the second-generation vibration-based (v-APAP) machines, during the first night treatment of OSAS.
  
  
  METHODS
  We retrospectively reviewed the polysomnography (PSG) recordings of 43 OSAS patients who were initially performed an overnight diagnostic PSG to confirm the disease and afterwards received the first night auto-CPAP treatment with using either the f-APAP (n=22) or v-APAP (n=21) device under another PSG evaluation.
  
  
  RESULTS
  There were 13.6% and 61.9% patients who remained a residual apnea/hypopnea index more than 5 during the f-APAP and v-APAP application, respectively (P<0.005). The f-APAP was more effective than the v-APAP in reducing apnea/hypopnea index (P=0.003), hypopnea index (P=0.023) and apnea index (P=0.007), improving the lowest oxygen saturation index (P=0.007) and shortening stage 1 sleep (P=0.016). However, the f-APAP was less sufficient than the v-APAP in reducing arousal/awakening index (P=0.02).
  
  
  CONCLUSIONS
  These findings suggest that the f-APAP works better than the v-APAP in abolishing breathing abnormities in the treatment of OSAS; however, the f-APAP device might still have some potential limitations in the clinical application.
authors.affiliation: Department of Otorhinolaryngology, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan; Sendai Snoring Research Centre, Miyoshi ENT Clinic, Sendai 981-3133, Japan.
authors.forename: Hai-Bo
authors.initials: HB
authors.lastname: Shi
authors.forename: Lei
authors.initials: L
authors.lastname: Cheng
authors.forename: Meiho
authors.initials: M
authors.lastname: Nakayama
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kakazu
authors.forename: Min
authors.initials: M
authors.lastname: Yin
authors.forename: Akira
authors.initials: A
authors.lastname: Miyoshi
authors.forename: Shizuo
authors.initials: S
authors.lastname: Komune
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D045422:Continuous Positive Airway Pressure / Q000295:instrumentation*; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D012189:Retrospective Studies; D020181:Sleep Apnea, Obstructive / Q000628:therapy*; D016896:Treatment Outcome