Removing nasal valve obstruction in peak nasal inspiratory flow measurement

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.