Correlation among clinical, functional and morphological indexes of the respiratory system in non-cystic fibrosis bronchiectasis patients

BACKGROUND: Non-cystic fibrosis bronchiectasis (NCFB) is a heterogeneous disease, which assessment and severity can’t be defined by one particular instrument but using a multidimensional score. Thus, in additional to traditional methods, alternative tools have been developed to assist these patients’ evaluation. OBJECTIVE: To correlate functional and morphological indexes with severity and dyspnea in NCFB patients, focusing on the correlation between the impulse oscillometry system (IOS) and the quantitative analysis of computed tomography (CT). METHODS: Clinically stable NCFB patients, between 18 and 80 years old were submitted to clinical, functional and morphological evaluations assessed by Bronchiectasis Severity Index (BSI) and Medical Research Council (MRC) scale; spirometry and IOS; and subjective and quantitative Chest CT scans analysis, respectively. RESULTS: This study included 38 patients. The best correlations obtained between functional and morphological airway indexes were: resistance at 5 Hz—R5 and the normalized thickness of bronchial walls—Pi10 (r = 0.57), and the mean forced expiratory flow (FEF(25-75%)) and CT score (r = -0.39). BSI as well as MRC showed higher correlations with the quantitative automated analysis of CT (BSI and Pi10: r = 0.41; MRC and Pi10: r = 0.35) than with subjective CT score (BSI and CT score: r = 0.41; MRC and CT score: r = 0.15); and moderate and weak correlations were obtained on both functional airway indexes (BSI and peripheral airways resistance - R5-R20: r = 0.53; BSI and forced expiratory volume at the first second—FEV(1): R = -0,64; MRC and R5-R20: r = 0.42; and MRC and VEF(1): r = -0.45). CONCLUSION: In NCFB patients, compartmentalized methods for assessing the respiratory system (IOS and the automated quantitative CT analysis) have a good correlation with severity and dyspnea.