Post-bronchodilator 1-FEV1/FEV3 as a measure of small airway dysfunction in childhood asthma

In preschool children, forced expiratory volume in 3 seconds (FEV3) has been suggested to estimate forced vital capacity with reasonable accuracy. The latter fraction of forced exhalation – exhalation after one second – could be more sensitive to detect early airway obstruction in asthma. We hypothesized that the ratio of the terminal expiration volume to FEV3 (1-FEV1/FEV3) would be a good reflection of airflow limitation and aimed to determine the clinical usefulness of post-bronchodilator 1-FEV1/FEV3 in childhood asthma.We utilized a retrospective observational cohort of children who underwent spirometry and bronchial provocation testing for asthma. Spirometry parameters were collected and compared between asthma and non-asthma groups. A total of 838 children aged ≤18 years were included in the analysis. Both pre-and post-bronchodilator 1-FEV1/FEV3 were obtained and compared regarding asthma status and severity.Post-bronchodilator 1-FEV1/FEV3 was significantly higher in the asthma group compared to the non-asthma group (12.9±5.0 vs. 10.1±4.4, P<0.001). In asthmatics, post-bronchodilator 1-FEV1/FEV3 was significantly higher in severe asthma than in mild-to-moderate asthma (16.5±4.8 vs. 12.8±5.0, P<0.001). The difference between pre-and post-bronchodilator 1-FEV1/FEV3 showed a significant correlation with the change in FEV1 (r=0.579, P<0.001).Post-bronchodilator 1-FEV1/FEV3 and the measured change after bronchodilator might ...
Source: European Respiratory Journal - Category: Respiratory Medicine Authors: Tags: 07.02 - Paediatric asthma and allergy Source Type: research