The effectiveness of supplemental oxygen during exercise training in patients with chronic obstructive pulmonary disease who show sever exercise-induced desaturation: a protocol for a meta-regression analysis and systematic review

Abstract Background: Supplemental oxygen during exercise training has been used to prevent hypoxemia or allow toleration of higher intensity training in patients with chronic obstructive pulmonary disease (COPD) who show exercise-induced desaturation. Although some meta-analyses examined the efficacy of supplemental oxygen during exercise training, these studies concluded that it does not further improve exercise tolerance compared to exercise training alone. However, supplemental oxygen during exercise training may be effective to improve exercise tolerance in COPD patients with severe desaturation during exercise under breathing room air or compressed air. Therefore, this study will be performed to elucidate the efficacy of supplemental oxygen during exercise training and the relationship between its efficacy and severity of desaturation during exercise at baseline.Methods: We will first assess the effectiveness of supplemental oxygen during exercise training in COPD. The main outcome is the change in exercise tolerance before and after the intervention, indicated by 6-minute walking distance or shuttle walking distance, and analyzed as the standardized mean difference (SMD). The quality and risk of bias in individual studies will be assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system and risk-of-bias tool (RoB ver.2). If statistical heterogeneity in effectiveness of exercise tolerance is shown, we will conduct meta-regression analyses to examine the association between efficacy of exercise training with supplemental oxygen and severity of desaturation at baseline.Discussion: One strength of this study is that it is a systematic review with meta-regression analysis to elucidate the effectiveness of supplemental oxygen during exercise training in patients with COPD who show sever exercise-induced desaturation. However, the quality and number of studies included meta-analysis may be low.Systematic review registration: Registration number, UMIN000039960.