Chronic effort dyspnea explained by lung function tests and by HRCT and CRX radiographic patterns in COPD: a post-hoc analysis in 51 patients.

This paper is a post-hoc analysis of a previous study performed to investigate the relationship between computerized tomography (CT) and lung function in 51 outpatients with mild-to-moderate COPD. We studied whether changes in lung function and radiographic patterns may help to explain dyspnea, the most disturbing symptom in patients with COPD. The Medical Research Council (MRC) dyspnea scale shows, by univariate analysis, a similar strength of association to CT expiratory lung density and to DL(CO), a functional index of lung parenchymal loss.

Speed of onset of bronchodilator response to salbutamol inhaled via different devices in asthmatics: a bioassay based on functional antagonism.

Aims: To evaluate the speed of onset of bronchodilation following salbutamol administered via a metered-dose inhaler with a spacer (pMDI + Volumatic) and a dry-powder inhaler (Diskus), as well as the relative potencies of these devices in asthmatic patients with methacholine-induced bronchoconstriction.

Methods: Eighteen patients inhaled methacholine (MCh) until FEV(1) decreased by 35% of control. Following administration of placebo, 200 microg salbutamol or 400 microg salbutamol through the pMDI + Volumatic or the Diskus, we calculated the time elapsed from drug administration and the appearance of a 90% increase in post-MCh forced vital capacity (FVC), FEV(1) and volume-adjusted mid-expiratory flow (recovery times).