Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, United Kingdom.
Belfast Health and Social Care Trust, Belfast, United Kingdom.
Ann Am Thorac Soc. 2022 Sep;19(9):1489-1497. doi: 10.1513/AnnalsATS.202006-584OC.
Lung clearance index (LCI) has good intravisit repeatability with better sensitivity in detecting lung disease on computed tomography scan compared with forced expiratory volume in 1 second (FEV) in adults with bronchiectasis. Alternative multiple-breath washout parameters have not been systematically studied in bronchiectasis. To determine the validity, repeatability, sensitivity, specificity, and feasibility of standard LCI (LCI), shortened LCI (LCI), ventilation heterogeneity arising within proximal conducting airways (SVT), and ventilation heterogeneity arising within the acinar airways (SVT) in a cross-sectional observational cohort of adults with bronchiectasis. Cross-sectional multiple-breath nitrogen washout data (Exhalyzer D; Eco Medics AG) from 132 patients with bronchiectasis across five United Kingdom centers (BronchUK Clinimetrics study) and 88 healthy control subjects were analyzed. Within-test repeatability (mean coefficient of variation) was <5% for both LCI and LCI in patients with bronchiectasis, and there was no difference in mean coefficient of variation for LCI and LCI in patients with bronchiectasis compared with healthy volunteers. Moderate-strength correlations were seen between FEV and LCI ( = -0.54), LCI ( = -0.53), SVT ( = -0.35), and SVT ( = -0.38) -scores. The proportion of subjects with abnormal multiple-breath washout (-score > 2) but in normal FEV (-score < -2) was 42% (LCI) and 36% (LCI). Overall results from the receiver operating characteristic curve analysis indicated that LCI had the greatest combined sensitivity and specificity to discriminate between bronchiectasis and control subjects, followed by LCI, FEV, and SVT -scores. There was a 57% time saving with LCI. LCI and LCI had good within-test repeatability and superior sensitivity compared with spirometry measures in differentiating between health and bronchiectasis disease. LCI is quicker and more feasible than LCI. Clinical trial registered with www.clinicaltrials.gov (NCT02468271).
肺清除指数 (LCI) 在检测支气管扩张症患者 CT 扫描中的肺部疾病方面具有较好的日内可重复性，且比第 1 秒用力呼气量 (FEV1) 更敏感。替代的多次呼吸冲洗参数尚未在支气管扩张症中进行系统研究。本研究旨在确定标准 LCI (LCI)、缩短 LCI (LCI)、近端传导气道内通气异质性 (SVT) 和腺泡气道内通气异质性 (SVT) 在支气管扩张症成人横断面观察队列中的有效性、可重复性、敏感性、特异性和可行性。分析了来自英国五个中心（BronchUK Clinimetrics 研究）的 132 例支气管扩张症患者和 88 例健康对照者的多呼吸氮冲洗数据（Exhalyzer D；Eco Medics AG）。支气管扩张症患者的 LCI 和 LCI 的日内重复性（平均变异系数）均<5%，支气管扩张症患者的 LCI 和 LCI 的平均变异系数无差异。FEV1 与 LCI（ = -0.54）、LCI（ = -0.53）、SVT（ = -0.35）和 SVT（ = -0.38）评分之间存在中度相关性。在正常 FEV1（-score<−2）但存在异常多次呼吸冲洗（-score>2）的患者中，有 42%（LCI）和 36%（LCI）。受试者工作特征曲线分析的总体结果表明，LCI 对区分支气管扩张症和对照组具有最大的敏感性和特异性，其次是 LCI、FEV1 和 SVT 评分。LCI 可节省 57%的时间。LCI 和 LCI 在区分健康和支气管扩张症疾病方面具有较好的日内可重复性和优于肺量计测量的敏感性。LCI 比 LCI 更快、更可行。该研究已在 www.clinicaltrials.gov 注册（NCT02468271）。
