Total amount: € 0,00
Official Journal of the Italian Society of Thoracic Endoscopy
Indexed/Abstracted in: EMBASE, Scopus
Online ISSN 1827-1723
Catapano G., Mannucci F., Mirarchi G., Prediletto R.
Istituto di Fisiologia Clinica e Fondazione “Gabriele Monasterio” Consiglio Nazionale delle Ricerche, Pisa, Italia
Aim. This study examined the role of the small airways in the pathogenesis of chronic obstructive pulmonary disease (COPD) and evaluated the utility of various assessment techniques in the early stages of the disease and their use in its management.
Methods. The study population comprised 45 patients with different stages of COPD severity (Gold stages), assessed by means of clinical (dyspnea according to the Medical Research Council), function at rest (plethysmography, blood gas analysis, pulmonary perfusion) and stress (ergospirometry) testing parameters. Additional assessment criteria comprised alveolar-arterial difference of respiratory gases (A-aDO2 and a-ADCO2), physiologic deadspace ventilation (Vd/Vt), and slope of the third alveolar phase of expired nitrogen after a single breath of 100% O2 (N2 slope) as potential indicators of small airway damage.
Results. In contrast to indices of hyperinflation, pulmonary diffusion and blood gas analysis, marked alterations in N2 slope, A-aDO2, a-ADCO2 and Vd/Vt were noted already at phase I of the disease. A significant correlation was found between these parameters and the degree of dyspnea, and ventilatory and cardiocirculatory failure as measured at exercise peak, particularly for the N2 slope. Ventilatory and cardiocirculatory response correlated significantly with the degree of exercise tolerance.
Conclusion. The study results indicate a possible role for functional indicators of small airways damage in revealing initial lung function abnormalities due to COPD, even before common parameters such as lung volume and gas exchange, and their role as predictors of the quality of life and possible targets of therapeutic response in this patient category.