It was hypothesised that noninvasive
positive-pressure ventilation (NPPV) applied during walking prevents exercise-induced hypoxaemia and improves exercise performance in severe
chronic obstructive pulmonary disease (
COPD) patients already receiving long-term NPPV. A total of 20
COPD patients (mean+/-sd age 65.1+/-8.7 yrs, forced expiratory volume in one second 27+/-8% predicted and total lung capacity 116+/-27%
pred) reporting dyspnoea, even during mild exertion, underwent two 6-min walking tests with a rollator and supplemental
oxygen (2.1+/-0.9 L.min(-1)) in a randomised cross-over design: with and without pressure-limited NPPV as used at home (inspiratory:expiratory pressure 2.9+/-0.44:0.4+/-0.1 kPa (29+/-4:4+/-1 mbar), respiratory frequency 20+/-2 breaths.min(-1)). The arterial
oxygen tension significantly increased by 1.39+/-1.43 kPa (95% confidence interval (CI) 0.71-2.07 kPa) after walking with NPPV, but significantly decreased by 1.43+/-1.06 kPa (95% CI -1.92 - -0.94 kPa) without NPPV. Dyspnoea, as assessed by the Borg dyspnoea scale, significantly decreased from 6 (interquartile range (IQR) 4.5-10) to 4 (1.5-4.5) and walking distance significantly increased from 209 (IQR 178-279) to 252 (203-314) m when walking was NPPV-aided. In chronic hypercapnic
chronic obstructive pulmonary disease, high-intensity noninvasive
positive-pressure ventilation can also be administered during walking with unchanged
ventilator settings compared with settings used at rest, thus resulting in improved oxygenation, decreased dyspnoea and increased walking distance. Therefore, noninvasive
positive-pressure ventilation during walking could prevent
hypoxia-induced complications and could, in future, play a role in
palliative care.