Effect of breathing re-training on end-tidal carbon-di-oxide in patients with asthma: a systematic review and meta-analysis

Abstract

Objective The review aims to determine the effect of breathing re-training on End-tidal carbon-di-oxide (ETCO2) in patients with asthma. Data sources A systematic search of articles was performed in PubMed, Cochrane, PEDro, Scopus, and Ovid databases from their inception till May 2022. Study selections Studies were included if the patients were clinically diagnosed with mild-moderate asthma. Randomized controlled trials that monitored ETCO2 as a primary or secondary outcome were included. Studies were examined for potential risk of bias using the Revised Cochrane risk of bias tool by two independent reviewers. Results Eight articles were included. The trials used various techniques like Buteyko, Papworth, Biofeedback, and holistic approach. Quantitative analysis was conducted to examine the effects on ETCO2 at various time points. A significant large effect was seen on ETCO2 following breathing re-training post-treatment, 3 and 6 months post-intervention. Conclusion There is moderate evidence for a significant effect of breathing re-training on ETCO2 in the short and long term in patients with asthma. However, high-quality randomized controlled trials using standardized measurement of ETCO2 are required to evaluate the effects of different breathing re-training techniques.