Abstract
Rationale
COPD is characterized by tissue and airway wall inflammation, distortion and destruction (emphysema, small airway disease). This trial tries to identify the influence of hallmark characteristics of COPD on regional ventilation in patients.
Methods
For 28 patients (21M, 66.3±6.4y, 8/18/2 GOLD II/II/IV, FEV1=43.9±11.9%p) FRI-based regional measures on lobar volume, hyperinflation, perfusion, emphysema and ventilation were obtained from breathing gated HRCT scans at FRC and TLC. A generalized estimating equation was fit to the data in order to predict regional ventilation in function of the other parameters, correcting for lobar repeated measures within a patient.
Results
A positive correlation was found between regional ventilation and static lung volume (p<0.001). Emphysema (p=0.017) and hyperinflation (p=0.028), independently, have a negative correlation with ventilation, while perfusion does not have a direct influence on ventilation (p=0.98).
Conclusions
It could be seen that airflow distribution is mainly driven by the static lobe volume, i.e. larger lobes attract more air than smaller lobes. However, this correlation is counteracted by the presence of emphysema and/or other reasons for hyperinflation. This means that also hyperinflated regions with predominant small airways disease receive less ventilation and hence a less optimal distribution of inhaled treatments.
This study was funded by Takeda.
- © 2014 ERS
