Background

Adding a slow vital capacity (SVC) to multiple breath washout (MBW) allows quantification of otherwise overlooked signal from under/un-ventilated lung units (UVLU) and may provide a more comprehensive assessment of airway disease than conventional lung clearance index (LCI_2.5).

Methods

We conducted a pilot study on people undergoing MBW tests: 10 healthy controls (HC) and 43 cystic fibrosis (CF) subjects performed an SVC after the standard end of test. We term the new outcome LCI with Short extension (LCI_ShX). We assessed (i) CF/ HC differences, (ii) variability (iii) effect of pulmonary exacerbation (PEx)/treatment and (iv) relationship with CF computed tomography (CFCT) scores.

Results

HC/ CF group differences were larger with LCI_ShX than LCI_2.5 (P<0.001). Within the CF group UVLU was highly variable and when abnormal it did not correlate with corresponding LCI_2.5. Signal showed little variability during clinical stability (n = 11 CF; 2 visits; median inter-test variability 2.6% LCI_ShX, 2.5% LCI_2.5). PEx signal was significantly greater for LCI_ShX both for onset and resolution. Both MBW parameters correlated significantly with total lung CT scores and hyperinflation but only LCI_ShX correlated with mucus plugging.

Conclusions

UVLU captured within the LCI_ShX varies between individuals; the lack of relationship with LCI_2.5 demonstrates that new, additional information is being captured. LCI_ShX repeatability during clinical stability combined with its larger signal around episodes of PEx may lend it superior sensitivity as an outcome measure. Further studies will build on this pilot data to fully establish its utility in monitoring disease status.

中文翻译：

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多次呼吸冲洗的短暂扩展为 CF 患者提供了远端气道疾病的额外信号：一项初步研究

背景

在多次呼吸冲洗 (MBW) 中添加缓慢的肺活量 (SVC) 可以量化来自通气不足/未通气的肺单位 (UVLU) 的其他被忽视的信号，并且可以提供比传统肺清除指数 (LCI _2.5 ) 更全面的气道疾病评估）。

方法

我们对接受 MBW 测试的人进行了一项初步研究：10 名健康对照 (HC) 和 43 名囊性纤维化 (CF) 受试者在标准测试结束后进行了 SVC。我们将新结果 LCI 称为短扩展 (LCI _ShX )。我们评估了 (i) CF/HC 差异，(ii) 变异性 (iii) 肺恶化 (PEx)/治疗的影响和 (iv) 与 CF 计算机断层扫描 (CFCT) 评分的关系。

结果

_{LCI ShX}的 HC/CF 组差异大于LCI _2.5 ( P <0.001)。在 CF 组内，UVLU 变化很大，当异常时，它与相应的 LCI _2.5无关。信号在临床稳定性期间几乎没有变化（n  = 11 CF；2 次就诊；中位测试间变异性 2.6% LCI _ShX， 2.5% LCI _2.5）。_{LCI ShX}的 PEx 信号在起始和分辨率方面都显着增加。两个 MBW 参数与总肺 CT 评分和过度充气显着相关，但只有 LCI _ShX与粘液堵塞相关。

结论

在 LCI _{ShX 中捕获的 UVLU}因个体而异；_{与 LCI 2.5}缺乏关系表明正在捕获新的附加信息。LCI _ShX在临床稳定性期间的可重复性与其在 PEx 发作周围的较大信号相结合，可能使其具有卓越的灵敏度作为结果测量。进一步的研究将建立在这些试点数据的基础上，以充分确定其在监测疾病状态方面的效用。