Prevention of exercise-induced asthma in an outdoor environment following bronchodialator use in asthmatic children
The purpose of this study was to determine if exercise-induced asthma (EIA) could be prevented in an outdoor environment in asthmatic children attending a summer camp 3 hours after their usual dose of medication. Most studies that test for ETA are done in a controlled environment which may make results not applicable to asthmatic children who spend a lot of their time outside. The relationship of aerobic fitness and level of activity to the severity of EIA were also examined. A total of 25 subjects (10.9+0.9 yrs, M±SD) were tested. Subjects were instructed to run around a grass field circular course (0.1 mile) for 5 minutes. The subjects could stop at any time. Baseline measurements of heart rate, respiratory rate and peak flow were determined before the test and at 1, 5, and 10 minutes following the end of the run. A fall in peak flow of >10% from baseline was considered positive for EIA. A total of 14 subjects experienced EIA following the run. There were no significant differences between the group who experienced EIA and those who did not in terms of heart rate, respiratory rate, or distance run. There was a significant difference between peak flow recordings as expected. Aerobic fitness and physical activity were not related to the severity of EIA. The results of this study suggests that additional medications may be needed to prevent EIA in these children in order to allow participation in activities which may produce EIA. Moreover, 3 hours may be beyond the protection time limit for some asthmatic children.