title: Inspiratory and fixed nasal valve collapse: clinical and rhinometric assessment.
abstract: BACKGROUND
  Acoustic rhinometry (AR) has been used to assess nasal valve obstruction. Standard AR measurement of the cross-sectional area (CSA) of the nasal valve is done in the apneic phase, whereas collapse often occurs on inspiration. We used the ratio of the CSA obtained during active inspiration and during apnea to compute a more meaningful method of diagnosing nasal valve collapse.
  
  
  METHODS
  AR was performed in 40 patients without nasal valve obstruction and 47 patients diagnosed with nasal valve obstruction. Patients with septal deflection or anterior inferior turbinate hypertrophy were excluded. The internal and external nasal valve area was observed during apnea and on active inspiration. AR measurement of the CSA of both nasal valves was performed during the apneic phase and during active inspiration and the CSA (inspiratory)/CSA (apneic) ratio was calculated.
  
  
  RESULTS
  The CSA (inspiratory)/CSA (apneic) ratio was > or = 1 in normal patients and in patients with fixed nasal valve collapse. The ratio was <1 in patients with inspiratory collapse. Data from history, physical examination, and dual-mode AR testing successfully differentiated patients into (1) normal valves, (2) fixed valve collapse, and (3) inspiratory valve collapse. A large number of patients with collapse had both internal and external valve obstruction and a large number also had a combination of inspiratory and fixed collapse.
  
  
  CONCLUSIONS
  Dual-mode AR testing is an effective tool in more precisely identifying nasal valve obstruction and is the first objective test shown to be highly diagnostic of inspiratory nasal valve collapse.
authors.affiliation: Department of Otolaryngology and Bronchoesophagology, Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois 60612-3833, USA.
authors.forename: Ramakrishnan
authors.initials: R
authors.lastname: Vidyasagar
authors.forename: Michael
authors.initials: M
authors.lastname: Friedman
authors.forename: Hani
authors.initials: H
authors.lastname: Ibrahim
authors.forename: Darius
authors.initials: D
authors.lastname: Bliznikas
authors.forename: Ninos J
authors.initials: NJ
authors.lastname: Joseph
mesh_terms: D001049:Apnea / Q000503:physiopathology*; D016022:Case-Control Studies; D006801:Humans; D015508:Nasal Obstruction / Q000175:diagnosis* / Q000503:physiopathology*; D009666:Nose / Q000473:pathology; D011446:Prospective Studies; D012016:Reference Values; D023842:Rhinometry, Acoustic / Q000379:methods; D012680:Sensitivity and Specificity