Comparison between unilateral PNIF and rhinomanometry in the evaluation of nasal cycle

Human unilateral nasal airflow shows spontaneous changes over a period of hours due to the alternating congestion and decongestion of the venous sinuses within the nasal turbinates and nasal septum. The aim of the present study was to compare PNIF and unilateral PNIF with nasal resistances measured by means of AAR in the evaluation of the nasal cycle.

PNIF, unilateral PNIF and AAR measurements were randomly performed in 20 non-smokers, non-asthmatic volunteers, with a SNOT 22 score lower than 1. Nasal measurements were done four times in a single day at 08.30, 11.00, 13.30 and 16.00. The correlation between PNIF, unilateral PNIF and nasal resistances was studied. The pattern of nasal airflow for each subject was also analyzed.

A significant negative correlation between PNIF-lPNIF-rPNIF and respectively AAR-lAAR-rAAR was found. Only 1 subject did not show nasal cycle, while all the rest were equally distributed between a reciprocal pattern of the nasal cycle, or an in-phase changes of the nasal cycle, both at PNIF and AAR.

Nasal cycle can be easily assessed by means of PNIF. In fact, AAR and PNIF showed a reasonable correlation in the measurement of nasal cycle, although PNIF offered a lower variability. Reciprocal and in-phase patterns of the nasal cycle were equally distributed in our population.