Nasal peak inspiratory and expiratory flow measurements for assessing nasal obstruction in allergic rhinitis.

BACKGROUND: Although nasal peak flow measurements have been proposed as a simple alternative method to assess nasal patency, which of nasal peak expiratory flow or nasal peak inspiratory flow (NPEF/NPIF) or the peak expiratory flow index or peak inspiratory flow index (PEFI/PIFI; the ratios between nasal and oral PEF or nasal and oral PIF, respectively) is the more accurate method is unclear. The aim of this study was to evaluate the correlation between NPEF, NPIF, PEFI, and PIFI, and blocked nose score (BNS) and mucociliary clearance time (MCCT) in diagnostic and follow-up assessments.

METHODS: Ninety-nine allergic rhinitis (AR) patients were treated with 220 micrograms once daily of intranasal triamcinolone acetonide for 28 days. BNS, NPEF, NPIF, PEFI, and PIFI and MCCT were used to evaluate treatment outcome. Correlations of initial visit scores and score changes after treatment between peak flow rates and BNSs and MCCTs were analyzed.

RESULTS: All nasal symptoms, peak flows, and MCCTs showed statistically significant improvements after the nasal steroid treatment. PEFI showed the best negative correlation with BNS and MCCTs, followed by PIFI, NPEF, and NPIF. Nasal peak flows showed better correlations with MCCTs than BNSs. Mean changes of peak flow rates between visits showed better correlation with BNSs and MCCTs than absolute values of peak flow rates at the initial visit.

CONCLUSION: Among nasal peak flow measurements, PEFI is the most appropriate objective tool for assessing nasal patency in AR. Peak flows can indicate underlying mucosal inflammation and are more sensitive to assess score changes after treatment than cross-sectional assessment at the initial visit.