Diaphragmatic excursion is correlated with the improvement in exercise tolerance after pulmonary rehabilitation in patients with chronic obstructive pulmonary disease

Masashi Shiraishi,Hisako Matsumoto,Yuji Higashimoto,Yuji Tohda,Osamu Nishiyama,Kanji Fukuda,Ryuji Sugiya,Yasutaka Chiba,Hiroki Mizusawa,Tamotsu Kimura,Yu Takeda,Shintarou Kudo,Shuhei Fujita

doi:10.1186/s12931-021-01870-1

Masashi Shiraishi, Hisako Matsumoto + Show 11 more

Open Access

https://doi.org/10.1186/s12931-021-01870-1

Copy DOI

Abstract

BackgroundIn patients with chronic obstructive pulmonary disease (COPD), the maximum level of diaphragm excursion (DEmax) is correlated with dynamic lung hyperinflation and exercise tolerance. This study aimed to elucidate the utility of DEmax to predict the improvement in exercise tolerance after pulmonary rehabilitation (PR) in patients with COPD.MethodsThis was a prospective cohort study. Of the 62 patients with stable COPD who participated in the outpatient PR programme from April 2018 to February 2021, 50 completed the programme. Six-minute walk distance (6MWD) was performed to evaluate exercise tolerance, and ultrasonography was performed to measure DEmax. Responders to PR in exercise capacity were defined as patients who demonstrated an increase of > 30 m in 6MWD. The receiver operating characteristic (ROC) curve was used to determine the cut-off point of DEmax to predict responses to PR.ResultsBaseline levels of forced expiratory volume in 1 s, 6MWD, maximum inspiratory pressure, DEmax and quadriceps muscle strength were significantly higher, and peak dyspnoea of modified Borg (mBorg) scale score was lower in responders (n = 30) than in non-responders (n = 20) to PR (p < 0.01). In multivariate analysis, DEmax was significantly correlated with an increase of > 30 m in 6MWD. The area under the ROC curve of DEmax to predict responders was 0.915, with a sensitivity and specificity of 83% and 95%, respectively, at a cut-off value of 44.9 mm of DEmax.ConclusionDEmax could adequately predict the improvement in exercise tolerance after PR in patients with COPD.

Highlights

In patients with chronic obstructive pulmonary disease (COPD), the maximum level of diaphragm excursion (DEmax) is correlated with dynamic lung hyperinflation and exercise tolerance
Several studies have shown that severe airflow limitation or poor exercise tolerance at baseline may predict a better response to pulmonary rehabilitation (PR) [5, 6], but another study has reported inconsistent findings [7]
We reported that there was an association between increased dyspnoea due to dynamic lung hyperinflation (DLH) on exercise and decreased exercise capacity in patients with COPD and reduced mobility of the diaphragm, which was assessed by the maximum level of diaphragm excursion (DEmax) using ultrasonography [9]

Summary

Introduction

In patients with chronic obstructive pulmonary disease (COPD), the maximum level of diaphragm excursion (DEmax) is correlated with dynamic lung hyperinflation and exercise tolerance. This study aimed to elucidate the utility of DEmax to predict the improvement in exercise tolerance after pulmonary rehabilitation (PR) in patients with COPD. Chronic obstructive pulmonary disease (COPD) is a progressive disease characterised by minimally reversible airflow limitation [1]. Pulmonary rehabilitation (PR) is a non-pharmacological intervention and has been reported to improve dyspnoea, exercise capacity and quality of life of patients with COPD [3]. Several studies have shown that severe airflow limitation or poor exercise tolerance at baseline may predict a better response to PR [5, 6], but another study has reported inconsistent findings [7]. One study reported that patients with severe dyspnoea did not respond well to PR and patients with milder dyspnoea responded well [8]

Objectives

Methods

Results

Discussion

Conclusion