The evaluation of regional lung function in COPD before and after pulmonary rehabilitation: a prospective clinical study

Abstract

BackgroundPulmonary rehabilitation (PR) is a widely recognized nonpharmacologic therapy for chronic obstructive pulmonary disease (COPD), but most of the current studies on whether PR can benefit COPD patients are based on the evaluation of symptoms and pulmonary function, which is limited to a certain extent. Therefore, based on the current study, this study evaluated the effects of individualized PR on the regional lung function in patients with stable COPD.MethodsThe patients with stable COPD were treated with PR for 2 weeks. The symptoms, global and regional lung function changes before and after 2-week program were evaluated using surveys, spirometry and electrical impedance tomography (EIT). The spatial coefficient of variation (CV) of regional spirometry parameters were calculated to quantified spatial heterogeneity of lung function. Temporal inhomogeneity was determined by the regional expiration time.ResultsAfter 2 weeks of intervention, the COPD assessment test score (CAT, 15.6±6.17 vs 11.1±5.85, P = 0.001), global spirometry forced expiratory volume in the first second (FEV1; 1.13±0.62 L vs 1.24±0.65 L, P = 0.006) and FEV1 % pred (43.3±21.34 % vs 48.3±24.22 %, P = 0.001) were improved. The CV for regional FEV1 / FVC (0.28±0.19 vs 0.17±0.06, P=0.012) differed significantly. Regional lung ventilation was more homogeneous and regional expiration time was shorter after PR.ConclusionThis study suggested that both spatial and temporal regional ventilation in COPD improved after the 2-week PR.