title: Predicting continuous positive airway pressure from a modified split-night protocol in moderate to severe obstructive sleep apnea-hypopnea syndrome.
abstract: BACKGROUND
  Most split-night sleep (SNS) studies have enrolled Caucasian patients with moderate-to-severe obstructive sleep apnea-hypopnea syndrome (OSAHS), with different apnea-hypopnea index (AHI) criteria for diagnosis and successful CPAP titration from the standard full-night study (FNS). This study aimed to describe a shortened diagnostic SNS in the Taiwanese population using diagnostic and CPAP therapeutic criteria identical to the standard FNS, and to generate a predictive equation for effective CPAP (Peff) titration.
  
  
  METHODS
  A total of 418 patients with moderate-to-severe OSAHS were enrolled in this study. The duration of the diagnostic SNS was shortened to approximately 1-2 hours. The diagnostic accuracy and the success rate of CPAP titration in SNS were evaluated and a statistical model for Peff was built. The accuracy of the predictive equation was validated in another 127 patients.
  
  
  RESULTS
  Eighty-nine percent of patients with moderate-to-severe OSAHS diagnosed in the preceding FNS yielded the same grade of OSAHS in SNS. These reproducible patients were more severe, with 88% attaining successful CPAP titration in SNS. The predictive Peff=1.98+0.184xBMI+0.01xAHISNS +0.016xDISNS (R2=0.28, p<0.0001) where BMI was the body mass index and DI the desaturation index. The | predictive Peff- Peff | was within 2 cm H(2)O in 84% of the study group and 73% of the validation group.
  
  
  CONCLUSIONS
  The modified split-night protocol and the predictive equation for CPAP can be useful in Taiwanese patients with moderate-to-severe OSAHS. Our findings may shorten the waiting time for polysomnography.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, China Medical University Hospital.
authors.forename: Ming-Lung
authors.initials: ML
authors.lastname: Chuang
authors.forename: I-Feng
authors.initials: IF
authors.lastname: Lin
authors.forename: Janine R E
authors.initials: JR
authors.lastname: Vintch
authors.forename: Yu-Fang
authors.initials: YF
authors.lastname: Liao
mesh_terms: D000328:Adult; D045422:Continuous Positive Airway Pressure; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography / Q000379:methods*; D012189:Retrospective Studies; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis* / Q000208:ethnology; D013624:Taiwan