COPD
-
Oxidative stress is implicated in the pathogenesis of asthma and chronic obstructive pulmonary disease (COPD). Analysis of the expired breath condensate (EBC) has been suggested to provide non-invasive inflammatory markers that reflect oxidative stress in the airways. ⋯ These findings suggest that oxidative stress is involved in the pathogenesis of asthma and COPD and that the H2O2 levels in EBC might reflect the health status in COPD.
-
Randomized Controlled Trial Comparative Study
Comparing dynamic hyperinflation and associated dyspnea induced by metronome-paced tachypnea versus incremental exercise.
Dynamic hyperinflation (DH) during exercise is associated with both dyspnea and exercise limitation in COPD. Metronome-paced tachypnoea (MPT) is a simple alternative for studying DH. We compared MPT with exercise testing (XT) as methods of provoking DH, and assessed their relationship with dyspnea. ⋯ Although greater during XT, the intensity of dyspnea bore no relationship to DH during either MPT and XT. MPT at 40 breaths/min and I:E of 1:1 elicits the greatest ∆IC, and is a more sensitive method for demonstrating DH. The relationship between DH and dyspnea is complex and not determined by DH alone.
-
Progressive decline in lung function has been widely accepted as the hallmark of chronic obstructive pulmonary disease (COPD); however, recent evidence indicates that the rate of decline measured as decline in forced expiratory volume in one second (FEV1) is higher in mild to moderate COPD than in severe COPD. Usually changes in FEV1 are measured in ml that is "absolute"; however, changes can also be measured "relative" as a percentage of the actual FEV1. We hypothesize that relative measurements could be more appropriate than absolute measurements for describing changes in lung function. ⋯ Measuring changes in relative terms could have important implications for the interpretation of results from clinical trials where FEV1 is the primary outcome. DLCST; www. ClinicalTrials.org , registration number: NCT00496977.