Efficient Use of Simple Exercise-Induced Bronchoconstriction Challenge Testing in Pediatric Exercise-Induced Dyspnea

BACKGROUND: A simple exercise test to evaluate for exercise-induced bronchoconstriction (FIB) is routinely ordered in pediatric patients with exercise-induced dyspnea. However, the utility of this test in establishing the cause of exercise-induced dyspnea is not thoroughly examined in the pediatric population. We sought to assess the efficiency of a simple EIB challenge test in finding the cause of exercise-induced dyspnea in pediatric patients referred to our tertiary center in the last 5 y. METHODS: We performed a retrospective chart review for all of these exercise tests done at Akron Children's Hospital from March 2011 to March 2016. Patients with chronic conditions (eg, cystic fibrosis, cardiac abnormality) were excluded. Demographics, clinical diagnosis of asthma, a presumptive diagnosis of exercise-induced asthma or EIB by the referring provider, symptoms with and without exercise, albuterol use, spirometry, and simple EIB challenge test results were collected. The chi-square test of independence was utilized in the examination of potential dependent relationships between categorical variables. A P value < .05 was considered to be statistically significant. RESULTS: Out of 164 enrolled subjects (57 males; age 6-20 y), only 19% showed evidence of EIB. There were no significant associations between EIB status (ie, EIB-positive or FIB-negative) based on exercise testing and gender, typical symptoms of EIB, diagnosis of exercise-induced asthma or EIB, and albuterol use (P > .05). However, a subject without asthma was 2.8 times more likely to have negative exercise test for EIB (odds ratio 2.8, 95% CI 1.3-6.5); in addition, approximately 85% of tests in subjects without asthma were negative. CONCLUSION: In a majority of subjects without asthma, a simple EIB challenge testing failed to uncover the cause of exercise-induced dyspnea and thus was inefficient. In these subjects, cardiopulmonary exercise testing may be more useful and cost-effective to explore other causes of dyspnea including EIB.