Oxygen supplementation during exercise training in copd: a rct

Abstract

Introduction/Aim Approximately 47 % of people with chronic obstructive pulmonary disease (COPD), referred to pulmonary rehabilitation, desaturate during exercise.

The aim was to determine whether supplementary oxygen during exercise training was more effective than medical air in improving exercise capacity and health‐related quality of life in people with COPD who desaturate to < 90% during the six‐minute walk test.

Methods Multi‐centre randomised controlled trial with randomisation (independent, concealed allocation), blinding (participants, exercise trainers and assessors) and intention‐to‐treat analysis. Participants were randomised to either an Oxygen Group (OG) or Air Group (AG). Both groups received the respective gas from a concentrator via nasal prongs at 5 litres/minute during exercise training of treadmill and cycle exercise, three times/week for eight weeks. Primary outcome measures were the endurance shuttle walk test (ESWT) and the Chronic Respiratory Questionnaire (CRQ). The study had ethics approval and trial registration.

Results 111 participants (60 males), mean (SD) age 69 (7) years, FEV1/FVC 0.43 (0.13), FEV1 46 (17) % predicted were recruited and 97 completed (OG n=52; AG n=45). Within‐group changes at 8 weeks were significant for ESWT, CRQ Total (T), CRQ Dyspnoea (D) (ESWT: OG mean difference [95%CI]: 163 s [76, 249]; AG 149 s [56, 242]; CRQ T: OG 0.4 points(pts) [0.2, 0.7]; AG 0.5 pts [0.2, 0.7]; CRQ D: OG 0.6 pts [0.3, 0.9]; AG 0.7 pts [0.3, 1.0] (all p<0.01). There were no between group differences with p> 0.05 for all outcomes.

Conclusion Exercise capacity and health‐related quality of life improved significantly in both groups, with no greater benefit from training with supplemental oxygen than with medical air. This is the largest rigorous RCT to report such findings.