title: Awake measures of nasal resistance and upper airway resistance on CPAP during sleep.
abstract: OBJECTIVE
  Since on CPAP, the nose is the primary determinant of upper airway resistance, we assess utility of noninvasive measures of nasal resistance during wakefulness as a predictor of directly assessed upper airway resistance on CPAP during sleep in patients with obstructive sleep apnea/hypopnea syndrome.
  
  
  METHODS
  Patients with complaints of snoring and excessive daytime sleepiness were recruited. 14 subjects underwent daytime evaluations including clinical assessment, subjective questionnaires to assess nasal symptoms and evaluation of nasal resistance with acoustic rhinometry (AR) and active anterior rhinomanometry (RM) in the sitting and supine positions. Patients underwent nocturnal polysomnography on optimal CPAP with measurements of supraglottic pressure to evaluate upper airway resistance. Comparisons were made between nasal resistance using AR and RM during wakefulness, and between AR and RM awake and upper airway resistance during sleep.
  
  
  RESULTS
  Our study shows that measures of awake nasal resistance using AR and RM had little or no correlation to each other in the sitting position, whereas there was significant but weak correlation in the supine position. Upper airway resistance measured while on CPAP during sleep did not show significant relationships to any of the awake measures of nasal resistance (AR or RM).
  
  
  CONCLUSIONS
  Awake measurements of nasal resistance do not seem to be predictive of upper airway resistance during sleep on CPAP.
authors.affiliation: Pulmonary Department, Corporacio Sanitaria Parc Tauli, Universitat Autonoma de Barcelona, Sabadell, Barcelona, Spain.
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Masdeu
authors.forename: Vijay
authors.initials: V
authors.lastname: Seelall
authors.forename: Amit V
authors.initials: AV
authors.lastname: Patel
authors.forename: Indu
authors.initials: I
authors.lastname: Ayappa
authors.forename: David M
authors.initials: DM
authors.lastname: Rapoport
mesh_terms: D000328:Adult; D000403:Airway Resistance / Q000502:physiology*; D000886:Anthropometry; D002940:Circadian Rhythm; D015331:Cohort Studies; D045422:Continuous Positive Airway Pressure / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography / Q000379:methods; D025363:Rhinomanometry / Q000379:methods; D023842:Rhinometry, Acoustic / Q000379:methods; D012720:Severity of Illness Index; D012890:Sleep; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis* / Q000628:therapy*; D014851:Wakefulness