Accuracy of peak nasal flow to determine nasal obstruction in patients with allergic rhinitis

Objective. The aim of this study was to investigate the ability of Peak Nasal Inspiratory Flow (PNIF) and Peak Nasal Expiratory Flow (PNEF) measures to predict symptoms of nasal obstruction. Methods. This is a cross-sectional study, carried out in 131 individuals (64 with symptomatic allergic rhinitis and 67 asymptomatic) aged between 16 and 50 years. Results. PNIF and PNEF were higher among non-rhinitis. In the curve analysis (receiver operating characteristic), a value of 115 was found for PNIF with a sensitivity of 98.4% and specificity of 87.5% (AUC = 0.99, p < 0.001) and 165 in PNEF with a sensitivity of 65.7% and specificity of 85.1% (AUC = 0.92, p < 0.001). Conclusions. PNIF and PNEF values were lower in patients with AR compared to asymptomatic cases. Our findings present reference values of PNIF and PNEF in the evaluation of nasal obstruction symptoms and reinforce the importance to complement more refined assessment of patients' symptoms. PNEF can be a valuable tool in screening patients and to complement PNIF measurement.