Comparison of Nasal Sound Spectral Analysis and Peak Nasal Inspiratory Flow before and after Decongestion in Patients with Nasal Obstruction

Abstract

We compared the results of nasal sound spectral analysis (NSSA) with the results of peak nasal inspiratory flow (PNIF) testing and use of a visual analog scale in patients with allergic rhinitis with nasal obstruction. We performed NSSA and PNIF testing on 38 patients with allergic rhinitis and 35 healthy subjects. A diagnostic decongestion test was performed on the patients (not on the control subjects). Twenty minutes after decongestant was sprayed into the nostrils, NSSA and PNIF testing were performed again. There was a significant difference in the PNIF values and the nasal inspiratory sound intensities before and after decongestion (p < 0.001). There was a correlation between the NSSA results at the frequency range of 2 to 4 kHz and the PNIF results. The calculated cutoffs between normal and pathological values were 14.8 dB (2 to 4 kHz) for NSSA and 116 +/- 14.1 L/min for PNIF testing. No significant differences were computed between NSSA and PNIF testing in terms of sensitivity (0.71 versus 0.76) or specificity (0.74 versus 0.80). Use of NSSA and PNIF testing together for assessment of nasal obstruction in allergic rhinitis provides clinical relevance in that it allows a fair degree of reliability. Such testing can be performed as a surrogate for rhinomanometry.