Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester University NHS Foundation Trust, Manchester, M23 9LT, UK.
Medicines Evaluation Unit, Southmoor Road, Manchester, M23 9QZ, UK.
Respir Res. 2024 Oct 3;25(1):357. doi: 10.1186/s12931-024-02972-2.
Expiratory flow limitation (EFL) can be detected using oscillometric reactance and is associated with a worse clinical presentation in chronic obstructive pulmonary disease (COPD). Reactance can show negative swings upon exhalation, which may develop at different rates between patients. We propose a new method to quantify the rate of EFL development; the EFL Development Index (ELDI).
A retrospective analysis of data from 124 COPD patients was performed. Data included lung function tests, Impulse Oscillometry (IOS), St Georges Respiratory Questionnaire (SGRQ), modified Medical Research Council (mMRC) scale and COPD Assessment Test (CAT) score. Fifty four patients had repeat data after 6 months. Twenty two patients had data recorded after 5 days of treatment with long acting bronchodilator therapy. EDLI was calculated as the mean expiratory reactance divided by the minimum expiratory reactance.
The mean ELDI was used to categorise patients with rapid onset of EFL (> 0.63; n = 29) or gradual onset (≤ 0.63; n = 34). Those with rapid development had worse airflow obstruction, lower quality of life scores, and greater resting hyperinflation, compared to those with gradual development. In patients with EFL, ELDI correlated with symptoms scores, airflow obstruction, lung volumes and gas diffusion. Both EFL and ELDI were stable over 6 months. EFL and EDLI improved with bronchodilator treatment.
COPD patients with rapid EFL development (determined by ELDI) had worse clinical characteristics than those with gradual EFL development. The rate of EFL development appears to be associated with clinical and physiological characteristics.
呼气流量限制 (EFL) 可使用振荡法电抗检测，并且与慢性阻塞性肺疾病 (COPD) 的临床表现更差相关。电抗在呼气时可能会出现负向摆动，这种摆动在不同患者中可能以不同的速度发展。我们提出了一种新的量化 EFL 发展速度的方法；EFL 发展指数 (ELDI)。
对 124 例 COPD 患者的数据进行回顾性分析。数据包括肺功能检查、脉冲振荡法 (IOS)、圣乔治呼吸问卷 (SGRQ)、改良版医学研究委员会呼吸困难量表 (mMRC) 和 COPD 评估测试 (CAT) 评分。54 例患者在 6 个月后重复了数据。22 例患者在接受长效支气管扩张剂治疗 5 天后记录了数据。ELDI 计算为平均呼气电抗除以最小呼气电抗。
使用平均 ELDI 将 EFL 快速发作 (>0.63；n=29)或缓慢发作 (≤0.63；n=34)的患者分类。与缓慢发作的患者相比，快速发作的患者气流受限更严重、生活质量评分更低、静息过度充气更大。在有 EFL 的患者中，ELDI 与症状评分、气流受限、肺容积和气体扩散相关。EFL 和 ELDI 在 6 个月内均稳定。EFL 和 ELDI 随着支气管扩张剂治疗而改善。
通过 ELDI 确定的 EFL 快速发展 (COPD) 患者的临床特征比 EFL 缓慢发展的患者更差。EFL 发展速度似乎与临床和生理特征相关。
