Effects of physiotherapeutic breathing therapy on ventilation distribution in cystic fibrosis

Electrical Impedance Tomography (EIT) is a non-invasive, radiation-free imaging method which can be utilized to measure regional lung ventilation distribution in patients with cystic fibrosis (CF). Up to now, the progression of CF-related lung diseases as well as therapy effects are monitored by spirometry or imaging methods such as computed tomography (CT). Since spirometry does not deliver any regional information of the lung function and CT cannot be applied frequently due to radiation, EIT might be a promising method to trace disease progression and therapy effects in CF-related lung diseases. In this preliminary study, the effects of physiotherapeutic breathing therapy on ventilation distribution in CF-related lung disease were investigated. Regional ratios of relative impedance changes corresponding to the forced expiratory volume in one second and the forced vital capacity (ΔIFEV1/ΔIFVC) were determined in three CF patients before and after therapy. Ventilation homogeneity was evaluated by a slightly modified version of the global inhomogeneity index (GIFEV1/FVC). In all three CF patients, variations in regional ratios of ΔIFEV1 and ΔIFVC could be observed, whereby peripheral lung regions seemed to be more affected by the therapy than other lung regions. However, all three CF patients showed a more homogenous ventilation distribution after the physiotherapeutic breathing therapy than before. These first results indicate the suitability of EIT to trace physiotherapeutic breathing therapy effects in CF-related lung disease, which might benefit a more patient-specific therapy.