Abstract
Background Exertional prolonged expiration should be identified as a therapeutic target in COPD. The efficacy of expiratory or inspiratory pressure load training (EPT/IPT) based on the degree of prolonged expiration was investigated.
Methods A total of 21 patients with COPD were divided into two groups according to the exertional change in the inspiratory duty cycle (TI/Ttot). For 12 weeks, patients whose exertional TI/Ttot decreased received EPT (EPT group, n=11, mean percentage forced expiratory volume in 1 s (%FEV1), 32.8%) and those whose exertional TI/Ttot increased received IPT (IPT group, n=10, mean %FEV1, 45.1%).
Results The therapeutic responses were as follows. In both groups, endurance time (EPT, +5.7 min, p<0.0001; IPT, +6.1 min, p=0.0004) on the constant work rate exercise test (WRET) and peak oxygen uptake increased (EPT, p=0.0028; IPT, p=0.0072). In the EPT group the following occurred: 1) soon after commencement of exercise with the constant WRET, the expiratory tidal volume (VTex) increased, reducing dyspnoea; 2) VTex and mean expiratory flow increased and then prolonged expiration (p=0.0001) improved at peak exercise with the incremental exercise test (ET); and 3) St. George's Respiratory Questionnaire total, activity and impact scores were improved. In the IPT group, on both the constant WRET and incremental ET, breathing frequency increased, which led to greater exercise performance with effort dyspnoea.
Conclusions This study showed the benefits of EPT/IPT on exercise performance. If the choice of managing COPD with EPT/IPT is appropriate, inexpensive EPT/IPT may become widespread as home-based training.
Abstract
Expiratory or inspiratory pressure load training (EPT/IPT) based on the degree of prolonged expiration improves exercise performance in COPD patients. If managing COPD with EPT/IPT is chosen appropriately, it could become widespread as home-based training. https://bit.ly/2ZWutWq
Footnotes
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Author contributions: All authors contributed substantially to this article. K. Miki conceived and designed the study, performed the experiments, analysed the data and wrote the manuscript. K. Tsujino and M. Miki conceived and designed the study, performed the experiments and analysed the data. K. Yoshimura, H. Kagawa, Y. Oshitani, K. Fukushima, T. Matsuki, Y. Yamamoto and H. Kida performed the experiments and analysed the data. Each author approved the submission of this manuscript for publication.
Conflict of interest: M. Miki has nothing to disclose.
Conflict of interest: K. Tsujino has nothing to disclose.
Conflict of interest: M. Miki has nothing to disclose.
Conflict of interest: K. Yoshimura has nothing to disclose.
Conflict of interest: H. Kagawa has nothing to disclose.
Conflict of interest: Y. Oshitani has nothing to disclose.
Conflict of interest: K. Fukushima has nothing to disclose.
Conflict of interest: T. Matsuki has nothing to disclose.
Conflict of interest: Y. Yamamoto has nothing to disclose.
Conflict of interest: H. Kida has nothing to disclose.
Support statement: This study was supported by a Grant-in-Aid for Clinical Research from the National Hospital Organization. Funding information for this article has been deposited with the Crossref Funder Registry.
- Received January 25, 2020.
- Accepted May 26, 2020.
- Copyright ©ERS 2020
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