Oxygen compared to air during exercise training in COPD with exercise-induced desaturation

Abstract

Almost half the patients referred to pulmonary rehabilitation with chronic obstructive pulmonary disease (COPD) desaturate during exercise. Although oxygen supplementation may ameliorate oxygen desaturation, the effects on outcomes of exercise training have not been rigorously evaluated. This study aimed to determine whether supplemental oxygen during exercise training was more effective than medical air in improving exercise capacity and health-related quality of life (HRQoL) in people with COPD.People with COPD who demonstrated oxygen desaturation <90% during the 6-min walk test were recruited to this multicentre trial with randomisation (independent, concealed allocation) to either an Oxygen group or Air group, blinding (participants, exercise trainers and European Respiratory Journal assessors) and intention-to-treat analysis. Both groups received the respective gas from concentrators via nasal prongs at 5 L·min−1 during exercise training consisting of treadmill and cycle exercise, three times per week for 8 weeks. Primary outcomes were the endurance shuttle walk test (ESWT) time and Chronic Respiratory Disease Questionnaire (CRQ)-Total score.111 participants (60 males), mean±sd age 69±7 years, with moderate to severe COPD were recruited and 97 completed (Oxygen group n=52; Air group n=45). At the end of the 8-week training programme there were no between-group differences in change in ESWT (mean difference 15 s (95% CI −106–136 s) or change in CRQ-Total (0.0 points (95% CI −0.3–0.3 points)). Within-group changes at end-training were significant for ESWT and CRQ-Total (all p<0.01).Exercise capacity and HRQoL improved in both groups, with no greater benefit from training with supplemental oxygen than medical air.

An update on pulmonary rehabilitation techniques for patients with chronic obstructive pulmonary disease

“…If there are clear signs of exercise-induced oxygendesaturation during the cardiopulmonary exercise test [55,56], the rehabilitation team may want to consider the use of oxygen supplementation during the whole-body exercise training, although its use has been questioned recently. Indeed, Alison and colleagues showed that a 10-week exercise training program was safe and effective in patients with COPD with mild exercise-induced O2-desaturation who were training with oxygen supplementation or room air supplementation [57].…”

“…Also, Garrod et al [95] showed no benefits of training with supplemental oxygen compared to room air in patients with EID regarding exercise tolerance or health status. Very recently, a large doubleblinded RCT showed that supplemental oxygen used during an 8-week supervised exercise training program in normoxemic COPD patients with EID did not result in greater improvements in exercise capacity than did medical air [57]. This was a large prospective-blinded study, but the investigators did not evaluate the acute response to oxygen supplementation.…”

Add‐on interventions during pulmonary rehabilitation

“…Individualized oxygen titration trials may identify individuals with COPD who respond to oxygen supplementation during exercise testing . However, a recently published randomized controlled trial of 111 COPD patients, normoxaemic at rest but with exercise induced desaturation below 90% oxygen saturation (SpO 2 ), showed no difference in improvement in exercise capacity and quality of life with supplemental oxygen during exercise training compared to air …”

Supplemental oxygen during exercise training in COPD: full of hot air?

“…In this issue of the European Respiratory Journal, ALISON et al [15] report on a double-blind randomised placebo-controlled trial that aimed to determine whether supplemental oxygen administered during exercise training was more effective than medical air in improving endurance exercise capacity, health-related quality of life, peak walking capacity, dyspnoea and physical activity levels in patients with COPD who desaturated during exercise (<90% during the 6-min walk test) but were normoxaemic at rest. Following random allocation to either oxygen or compressed air, both groups underwent an 8-week training programme with three supervised exercise sessions per week.…”

“…ALISON et al [15] should be congratulated in rigorously conducting the largest study to date to examine the role of supplemental oxygen during exercise training in patients with COPD and EID. They provide convincing data that the majority of patients with COPD and EID safely benefit from exercise training without the need for supplemental oxygen.…”