Peak nasal inspiratory flow and peak expiratory flow. Upright and sitting values in an adult population

Background: Nasal obstruction is correlated with a decreased quality of life . An easy way to evaluate nasal patency is the peak nasal inspiratory flow (PNIF) measurement. Normal PNIF values have been published by many authors. However, some authors evaluated volunteers in a sitting position, while others have measured PNIF values in standing volunteers. Body position has been shown to influence pulmonary function, with differences between sitting and upright positions. As nasal and pulmonary flows are strictly related, the present pilot study tried to establish whether PNIF/PEF changed with body position in adults. Methodology/Principal: PNIF and PEF were measured in sitting and standing positions with the order of testing randomized in 76 healthy volunteers, 30 male (40 ±16 years). Results: In the group as a whole between sitting and upright position, PEF was significantly different (p=0.009), while PNIF showed a trend towards a significant difference (p=0.10). Conclusions: The present study, although showing a generally positive effect of the standing position on PEF values, does not show a clear effect on PNIF