Infection, Immunity and Inflammation Research and Teaching Department, UCL Great Ormond Street Institute of Child Health (UCL GOS ICH), London, UK.
Heart and Lung Directorate, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK.
Pediatr Pulmonol. 2024 Dec;59(12):3085-3094. doi: 10.1002/ppul.27177. Epub 2024 Jul 19.
The multiple breath washout (MBW) test is widely reported in the context of Lung Clearance Index (LCI). LCI reflects global ventilation inhomogeneity but does not provide information regarding the localization of disease along the respiratory tree. The MBW-derived normalized phase III slope (S) indices (S and S), instead, can distinguish between convective-dependent and diffusion-convection-dependent ventilation inhomogeneity considered to occur within the conductive and acinar airways, respectively. In cystic fibrosis, S tends to become abnormal even earlier than LCI and spirometry. The value of S and S in clinical practice has been recently explored in other respiratory conditions, including asthma, primary ciliary dyskinesia, bronchopulmonary dysplasia, bronchiolitis obliterans, and sickle cell disease. In this narrative review we offer an overview on the theoretical background, potentialities, and limitations of S analysis in children, including challenges and feasibility aspects. Moreover, we summarize current evidence on the use of S-derived indices across different groups of pediatric chronic respiratory disease and we highlight the gaps in knowledge that need to be addressed in future studies.
多次呼吸冲洗（MBW）试验在肺清除指数（LCI）的背景下被广泛报道。LCI 反映了全局通气的不均匀性，但不能提供关于呼吸树中疾病定位的信息。相反，MBW 衍生的标准化相位 III 斜率（S）指数（S 和 S）可以区分被认为分别发生在传导和腺泡气道中的对流依赖和扩散-对流依赖通气的不均匀性。在囊性纤维化中，S 倾向于比 LCI 和肺活量计更早变得异常。S 和 S 在临床实践中的价值最近在其他呼吸系统疾病中进行了探索，包括哮喘、原发性纤毛运动障碍、支气管肺发育不良、闭塞性细支气管炎和镰状细胞病。在这篇叙述性综述中，我们概述了 S 分析在儿童中的理论背景、可能性和局限性，包括挑战和可行性方面。此外，我们总结了 S 衍生指数在不同儿科慢性呼吸疾病组中的应用的现有证据，并强调了需要在未来研究中解决的知识差距。
