Abstract
50 COPD patients were studied during an episode of acute exacerbation (AE). Functional respiratory imaging (FRI) endpoints, PFT parameters and PRO measures were obtained during AE and 6-8 weeks after recovery. An FEV1 increase from 45±15 to 52±17%pred (p<0.01) was observed. This ΔFEV1 was, on a global level, mostly influenced by the lung Δhyperinflation even more than by the Δairway volume, both measured by FRI. We aimed to study how ΔFEV1 is explained by changes in regional FRI measures.
The relations were tested using multiple regression models (MRM). Three different types of regional FRI (airway volume and resistance, and hyperinflation) inputs were used to predict FEV1 changes:
Central airways (generations 1-2) versus larger airways (generations 3-10) (MRM1)
Upper (right upper, right middle and left upper lobe) versus lower lobes (right lower and left lower lobe) (MRM2)
Central airways combined with split upper/lower lobes for the larger airways (generations 3-10) (MRM3)
45%, 63% and 92% of the variation in the improvement in FEV1 was explained by MRM1, MRM2 and MRM3, respectively (all p<0.01, Anova χ2). MRM3 was a significantly better predictor of ΔFEV1 as compared to MRM2, which in its turn was better than MRM1 (both p<0.01, Anova χ2).
The analysis suggests that changes in FEV1 after the recovery from AE are mainly influenced by the responses in airway volume/resistance and hyperinflation that is observed in both the upper and lower lobes separately. FRI parameters were able to explain >90% of the change in FEV1.
- Copyright ©ERS 2015
