Abstract
Within-breath change in reactance at 5Hz during tidal breathing reliably detects EFL in patients with COPD. We used the method proposed by Dellaca et al to determine presence of EFL and its relationship to spirometry and demographics of 424 healthy smokers and COPD patients from the Bergen cohort of the ECLIPSE study.
Aim: Establish the prevalence of EFL by GOLD stage and its relationship to dyspnoea and BMI.
274 stable COPD patients and 150 healthy smoking controls performed spirometry and tidal impulse oscillometry.
Results: Presence of EFL in healthy smokers, COPD grade 2,3, and 4 was.7%, 13%, 28% and 40% respectively. Inspiratory resistance and reactance at 5Hz were higher in COPD than smokers but differed little across GOLD stages.
Demographics
Conclusion: EFL became more common in higher GOLD stages, but a significant number of patiens in all GOLD stages were not flow limited at rest. In GOLD stage 2 and 3 EFL patients were more breathless, despite similar spirometry, but EFL also tracked obesity, which may contribute to both EFL and dyspnoea. Presence of EFL has potential to be an independent phenotypic characteristic in stable COPD.
- © 2011 ERS
