What is the most reliable objective measurement for nasal patency assessment?
Background: Nasal obstruction is a common symptom that affects a large proportion of the population. The correlation between rhinomanometry and acoustic rhinometry and the individual subjective sensation of nasal patency remains controversial. According to the study authors, only a limited number of studies concerning nasal patency were performed using peak oral inspiratory flow (POIF) and the nasal patency index (NPI).
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December 2014Study design: Prospective cohort study of 131 volunteers of both genders, aged 18 years or older, with or without nasal symptoms, who received treatment between November 2012 and January 2013.
Setting: Department of Otorhinolaryngology, Academic Medical Center, Amsterdam, Netherlands.
Synopsis: Overall, 60.3% of the participants had undergone prior nasal surgery: 21.4% had undergone septoplasty, 0.8% had inferior turbinate reduction, 2.3% had a combination of the two, 16% had rhinoplasty, and 20.6% had undergone functional endoscopic sinus surgery. With respect to lower airways, 23.7% of participants reported some kind of pulmonary disease (16.8% used a corticosteroid inhaler; 3.8% used a bronchodilator). Finally, 24.4% of the participants were smokers. NPI showed significant correlations with the nasal obstruction symptom evaluation (NOSE) scale and NP-VAS; however, these correlations were not more significant compared to the results of peak nasal inspiratory flow (PNIF). PNIF, NPI, and NP-VAS were significantly associated with the NOSE scale, after confounder adjustment. POIF, however, was not significantly associated with the NOSE scale. PNIF, NPI, and NP-VAS correlate with the NOSE scale or the subjective perception of nasal passage. POIF did not show this correlation. Spirometric peak flow measurements represent relatively simple methods to estimate the patency of the nasal airway. Oral and nasal peak inspiratory flows can be expressed in an NPI, which up to now has been used in a few studies. Authors observed a strong relation between POIF and PNIF, confirming that PNIF strongly depends on pulmonary function. The main limitation is that the full cooperation of tested subjects is crucial for the validity of PNIF and POIF measurement, and PNIF increases with practice.
Bottom line: Peak nasal inspiratory flow is the most reliable method for the assessment of nasal patency. There is no clinical need to measure peak oral inspiratory flow or to calculate the nasal patency index in the evaluation of nasal patency.