Abstract
In a cross-over RCT, portable NIV (pNIV) reduced dynamic hyperinflation (DH) compared to pursed lip breathing (PLB) during intermittent exercise in COPD, but not consistently in all subjects. In this post-hoc analysis, DH response was defined as a reduction ≥4.5% of predicted resting inspiratory capacity with pNIV compared to PLB.
At exercise iso-time (where work completed was consistent between pNIV and PLB), 8/24 patients were DH non-responders (DH: 240±40ml, p=0.001 greater using pNIV). 16/24 were DH responders (DH: 220±50ml, p=0.001 lower using pNIV). Compared to DH responders, DH non-responders exhibited greater resting DH (RV/TLC: 65±4% versus 56±2%; p=0.028) and did not improve exercise tolerance (pNIV: 30.9±3.4 versus PLB: 29.9±3.3 min; p=0.603). DH responders increased exercise tolerance (pNIV: 34.9±2.4 versus PLB: 27.1±2.3 min; p=0.001). Resting RV/TLC% was negatively associated with the magnitude of DH when using pNIV compared to PLB (r=-0.42; p=0.043).
Patients with profound DH were less likely to improve exercise tolerance with pNIV. Further studies using auto-adjusted ventilators are warranted.
Footnotes
Cite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 947.
This abstract was presented at the 2020 ERS International Congress, in session “Respiratory viruses in the "pre COVID-19" era”.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
- Copyright ©the authors 2020
