title: Removing nasal valve obstruction in peak nasal inspiratory flow measurement.
abstract: BACKGROUND
  Peak nasal inspiratory flow (PNIF) measurements are used to evaluate nasal obstruction and as a surrogate for disease activity in allergic rhinitis and other nasal complaints. This measurement can give erroneous results when forced inspiration leads to nasal valve collapse.
  
  
  OBJECTIVE
  To determine the effects of 2 different nasal stents (Sinuscone and Nozovent) on valve collapse and repeatability of PNIF measurements.
  
  
  METHODS
  Repeated measurements of PNIF were obtained in 74 individuals with and without 2 different nasal stents: Sinuscone and Nozovent.
  
  
  RESULTS
  The mean (95% confidence interval) improvement in PNIF was 1.7 L/min (-2.4 to 5.8 L/min; P = .42) with Nozovents and 25.4 L/min (11.4 to 39.4 L/min; P = .001) with Sinuscones. The PNIF coefficient of variation for repeatability was 11.6% without stents, 16.0% using Nozovents, and 10.4% using Sinuscones.
  
  
  CONCLUSIONS
  Sinuscones, but not Nozovents, significantly improved PNIF. Repeatability of PNIF measurements was worse with Nozovents and only marginally improved with Sinuscones.
authors.affiliation: Asthma and Allergy Research Group, Department of Medicine and Therapeutics, Ninewells Hospital and Perth Royal Infirmary, University of Dundee, Dundee, Scotland. mbarnes@rcsed.ac.uk
authors.forename: Martyn L
authors.initials: ML
authors.lastname: Barnes
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Lipworth
mesh_terms: D006801:Humans; D007320:Inspiratory Capacity / Q000502:physiology*; D015508:Nasal Obstruction / Q000175:diagnosis*; D015203:Reproducibility of Results; D012129:Respiratory Function Tests / Q000295:instrumentation / Q000379:methods; D012130:Respiratory Hypersensitivity / Q000175:diagnosis; D025363:Rhinomanometry / Q000295:instrumentation* / Q000379:methods; D015607:Stents