Background: When assessing asthma, FEV1 is often the only functional parameter considered. Aim: To evaluate if there is a positive response to bronchodilators in school children with asthma and normal FEV1. To correlate this results with clinical parameters of disease. Method: 100 asthmatic children with normal FEV1 were included and submitted to lung function testing with bronchodilation. We evaluated bronchodilator response (BDR) and questioned them about several clinical aspects (daily medication, rescue medication, asthma exacerbations, nocturnal symptoms and exercise-induced symptoms), in the past 3 months. We considered a normal FEV1 when it was 80% of the predicted value (PV) and a positive BDR when FEV1 increased for at least 12% after administration of bronchodilators. Results: Sixty male and forty female patients; mean age (±SD) 12.4 (±3.8) years; 85 were atopic; 18 patients had intermittent asthma, 56 mild persistent and 26 moderate persistent asthma. There was a positive BDR in 34 patients (I group). In this group, 15 patients referred nocturnal and/or exercise-induced symptoms vs. 18/66 from those with a negative BDR (II group) and 14/34 from the first group had asthma exacerbations within the past 3 months vs. 6/66 patients from the II group (p<0.05). Regarding daily medication, 21/34 patients with positive BDR and 50/66 from those with negative BDR were on inhaled corticosteroids. Conclusion: In this study 34% of asthmatic children had a positive BDR, although presenting normal FEV1. A positive BDR correlated with clinical parameters, mainly with recent asthma exacerbations.
Kamenov et al. (2014) studied this question.