Optimised oxygenation improves functional capacity during daily activities in patients with COPD on long-term oxygen therapy: a randomised crossover trial.

Abstract

Minimising hypoxaemia during submaximal walking tests has a positive effect on exercise capacity and dyspnoea in patients with chronic obstructive pulmonary disease (COPD) on long-term oxygen therapy (LTOT). However, the impact of optimising oxygenation during everyday tasks remains unexplored. Therefore, we investigated the effects of maintaining a target saturation on activities of daily living (ADL) using automated oxygen titration compared with conventional fixed oxygen flow. In a double-blinded, randomised crossover trial, patients with COPD on LTOT performed two GlittreADL tests to assess the functional capacity of everyday activities using (1) their fixed oxygen dose and (2) an adjusted flow from 0 to 8 L/min targeting a peripheral oxygen saturation (SpO₂) of 90-94%. A closed-loop device automatically titrated the oxygen based on information from a Bluetooth wrist pulse oximeter. 31 patients (mean±SD age: 72.8±5.9 years, forced expiratory volume in 1 s of % predicted: 36.7±12.7) were included. The patients reduced the time to perform the ADL test by median (IQR) 38 (12-73) s, p<0.001, using automated titration compared with the fixed oxygen flow. The oxygen flow in the automated arm more than tripled to 5.4 (4.1-6.8) versus 1.6 (1.1-2.1) L/min (fixed) during the test, p<0.001, while the time spent within SpO₂-target was increased from 19% to 49%, p=0.002. Correspondingly, the patients experienced less dyspnoea (BorgCR10); 5 (3-7) versus 6 (4-8), p<0.001, in favour of the automated oxygen titration. Improving oxygenation and extending the time spent within target saturation reduced dyspnoea and improved functional capacity in ADL in patients with COPD on LTOT. NCT05553847.