title: Nasal resistance for determinant factor of nasal surgery in CPAP failure patients with obstructive sleep apnea syndrome.
abstract: OBJECTIVE
  Given that criteria for nasal surgery in individuals with obstructive sleep apnea syndrome (OSAS) have not been proposed, we investigated the effectiveness of nasal surgery for CPAP failure in patients with both severe OSAS and nasal obstruction.
  
  
  METHODS
  Conventional nasal surgery was performed in 12 patients who were refractory to treatment by CPAP. The subject group consisted of 12 males (mean age, 54.2 +/- 9.2 years; range 39-66 years). The effect of nasal surgery was evaluated with data from preoperative and postoperative polysomunography. The nasal resistance value was first deduced to determine which OSAS patients with CPAP failure should undergo nasal surgery, compared to control values.
  
  
  RESULTS
  Nasal surgery resulted in a significant decrease in nasal resistance, as measured by rhinomanometry, from 0.57 +/- 0.31 Pa/cm3 /sec to 0.16 +/- 0.03 Pa/cm3/sec and rendered all patients tolerant to CPAP. In addition, the lowest nocturnal oxygen saturation significantly increased from 68.3 +/- 12.1% to 75.3 +/- 7.1% after surgery. Subjectively, Epworth sleepiness scale (ESS) significantly decreased from 11.7 +/- 4.1 to 3.3 +/- 1.3 after surgery, but the number of apnea and hypopnea episodes per hour did not change significantly. In five patients, for whom it was possible to perform a CPAP titration before nasal surgery, the value decreased significantly from 16.8 +/- 1.1 to 12.0 +/- 1.9 cmH2O. The bilateral nasal resistance of the 410SAS patients with CPAP therapy (control group) was 0.24 +/- 0.11 Pa/cm3/sec. The cut off value for differentiation between CPAP failure patients and control group was determined as 0.38 Pa/cm3 /sec.
  
  
  CONCLUSIONS
  Increased nasal resistance is a determinant of CPAP failure, and the surgical correction of severe nasal obstruction should thus be considered to facilitate treatment of OSAS patients with CPAP.
authors.affiliation: Department of Otorhinolaryngology, Nagoya University School of Medicine, Nagoya, Japan. seisay@tsuru.med.nagoya-u.ac.jp
authors.forename: Seiichi
authors.initials: S
authors.lastname: Nakata
authors.forename: Akiko
authors.initials: A
authors.lastname: Noda
authors.forename: Hidehito
authors.initials: H
authors.lastname: Yagi
authors.forename: Eriko
authors.initials: E
authors.lastname: Yanagi
authors.forename: Tamie
authors.initials: T
authors.lastname: Mimura
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Okada
authors.forename: Hayato
authors.initials: H
authors.lastname: Misawa
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nakashima
mesh_terms: D000328:Adult; D000368:Aged; D045422:Continuous Positive Airway Pressure; D006801:Humans; D008297:Male; D008875:Middle Aged; D015508:Nasal Obstruction / Q000150:complications / Q000601:surgery*; D017286:Polysomnography; D025363:Rhinomanometry; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology / Q000601:surgery* / Q000628:therapy; D018709:Statistics, Nonparametric; D016896:Treatment Outcome