Abstract

Forced expiratory volume in one second (FEV1) is often used for determining reversibility in COPD patients. But it’s suggested that parameters like (forced vital capacity) FVC and (inspiratory capacity) IC can increase with bronchodilators in some patients who are not reversible according to FEV1, and they may be used for determining the efficacy of the bronchodilator treatment. We aimed to investigate the role of FVC and IC for detecting reversibility and the relationship between these parameters and FEV1. 54 stable patients were included and PFT were performed before the inhalation of 200µgr salbutamol and repeated after 15 minutes. Reversibity was defined as an increase in FEV1 (≥10%) and/or an increase in absolute FEV1 (>200 ml) after salbutamol. For FVC and IC, reversibility was defined as > or = 10% after bronchodilator. Ten of 33 patients who had irreversible obstruction according to FEV1 had an increase in FVC; 10 of 33 had an increase in IC at least 10% or more. Six patients who had reversibility according to FVC and IC were same persons. In consider to increase in FVC and IC (≥10%) after bronchodilator inhalation 42% of all irreversible patients were defined as reversible. Spirometric tests used in COPD are weak indicators. We suggest that to detect airway reversibility in COPD patients, IC should also be added to conventional spirometric parameters. In addition, prospective studies which investigate the association with these parameters and bronchodilator therapy may denote detecting comprehensive response of bronchodilator therapy and prognosis in COPD patients.