Eucapnic Voluntary Hyperventilation to Detect Exercise-Induced Bronchoconstriction in Cystic Fibrosis

Background Exercise-induced bronchoconstriction (EIB) has not been well studied in cystic fibrosis (CF), and eucapnic voluntary hyperventilation (EVH) testing has not been used as an objective assessment of EIB in CF to date. Methods A prospective cohort pilot study was completed where standard EVH testing was completed by 10 CF patients with forced expiratory volume in 1 s (FEV 1 ) ≥70 % of predicted. All patients also completed a cardiopulmonary exercise test (CPET) with pre- and post-CPET spirometry as a comparative method of detecting EIB. Results No adverse events occurred with EVH testing. A total of 20 % (2/10) patients were diagnosed with EIB by means of EVH. Both patients had clinical symptoms consistent with EIB. No patient had a CPET-based exercise challenge consistent with EIB. Conclusions EVH testing was safe and effective in the objective assessment for EIB in patients with CF who had well-preserved lung function. It may be a more sensitive method of detecting EIB then exercise challenge.