Department of Medicine, Oregon Health and Science University (OHSU), Portland, Oregon, United States of America.
Department of Medicine, University of North Carolina (UNC), Chapel Hill, North Carolina, United States of America.
PLoS One. 2022 May 20;17(5):e0268622. doi: 10.1371/journal.pone.0268622. eCollection 2022.
Cystic fibrosis (CF) is an inherited disorder causing impaired mucociliary clearance within the respiratory tract, and is associated with bronchiectasis, chronic respiratory infections, and early death. Airway clearance therapies have long been a cornerstone of management of individuals with CF, although evidence supporting their use is lacking. We designed a randomized controlled trial to quantitatively compare the effects of different forms of airway clearance on mucociliary clearance.
Three different physiotherapy methods to augment cough-clearance were studied in addition to cough-clearance alone: high-frequency chest-wall oscillating vest, oscillatory positive expiratory pressure, and whole-body vibration. We used gamma scintigraphy after inhalation of radiolabeled particles to quantify mucus clearance before, during, and after physiotherapy. As secondary endpoints, we measured concentrations of small molecules in exhaled breath that may impact mucus clearance.
Ten subjects were enrolled and completed study procedures. No differences were identified between any method of airway clearance, including cough clearance alone. We did identify changes in certain small molecule concentrations in exhaled breath following airway clearance.
Due to the limitations of this study, we do not believe the negative results suggest a change in clinical practice with regard to airway clearance. Findings pertaining to small molecules in exhaled breath may serve as future opportunities for study.
囊性纤维化（CF）是一种遗传性疾病，导致呼吸道内的黏液纤毛清除功能受损，与支气管扩张、慢性呼吸道感染和早逝有关。气道清除疗法一直是 CF 患者管理的基石，尽管缺乏支持其使用的证据。我们设计了一项随机对照试验，定量比较不同形式的气道清除对黏液清除的影响。
除单独咳嗽清除外，还研究了三种不同的物理治疗方法来增强咳嗽清除：高频胸壁振荡背心、振荡性呼气正压和全身振动。我们在吸入放射性标记颗粒后使用伽马闪烁法来量化物理治疗前后的黏液清除。作为次要终点，我们测量了呼气中小分子的浓度，这些小分子可能会影响黏液清除。
10 名受试者入组并完成了研究程序。任何气道清除方法（包括单独咳嗽清除）之间均未发现差异。我们确实在气道清除后发现呼出气体中某些小分子浓度发生了变化。
由于本研究的局限性，我们认为阴性结果并不意味着气道清除方面的临床实践会发生改变。呼出气体中小分子的发现可能为未来的研究提供机会。
