小气道功能障碍(SAD)越来越被认为是小儿哮喘的重要特征,但通常依赖于肺活量测定法衍生的FEF25-75来检测其存在。多次呼吸冲洗(MBW)和示波法可能为SAD检测提供改进的灵敏度,但与FEF25-75相比,它们的效用以及与学龄期哮喘临床结局的相关性仍不清楚.我们使用这些技术调查了SAD的发生,57名8-18岁哮喘儿童的试验间相关性和与临床结局的联系。MBW和肺活量异常定义为z分数高于/低于±1.96,从同期对照(n=69)生成MBW参考方程。异常振荡测量被定义为>97.5百分位数,也来自同期对照(n=146)。具有异常FEF25-75,MBW,或示波法被认为有SAD。利用这些正常的极限,SAD在示波测定法中的发生率为63%(电阻在5-20Hz;R5-R20;>97.5百分位数),54%的MBW(Scond;z分数>1.96)和44%的参与者的肺活量测定FEF25-75(z分数<-1.96)。SAD,由示波法和/或MBW异常定义,发生在77%。在R5-R20异常的患者中,Scond异常的占71%。相关性表明R5-R20和Scond都与哮喘药物负担有关,基线FEV1和可逆性。此外,Scond与FENO和支气管高反应性的大小相关。SAD,通过示波法和/或MBW检测,发生在近80%的学龄儿童中,超过FEF25-75检出率。不一致的振荡和MBW异常表明它们反映了SAD的不同方面,作为补充工具。哮喘的主要临床特征,比如可逆性,与MBW衍生的Scond的相关性强于示波法衍生的R5-R20。
UNASSIGNED: Small airway dysfunction (SAD) is increasingly recognized as an important feature of pediatric asthma yet typically relies on spirometry-derived FEF25-75 to detect its presence. Multiple breath washout (MBW) and oscillometry potentially offer improved sensitivity for SAD detection, but their utility in comparison to FEF25-75, and correlations with clinical outcomes remains unclear for school-age asthma. We investigated SAD occurrence using these techniques, between-test correlation and links to clinical outcomes in 57 asthmatic children aged 8-18 years.
UNASSIGNED: MBW and spirometry abnormality were defined as z-scores above/below ± 1.96, generating MBW reference equations from contemporaneous controls (n = 69). Abnormal oscillometry was defined as > 97.5th percentile, also from contemporaneous controls (n = 146). Individuals with abnormal FEF25-75, MBW, or oscillometry were considered to have SAD.
UNASSIGNED: Using these limits of normal, SAD was present on oscillometry in 63% (resistance at 5-20 Hz; R5-R20; >97.5th percentile), on MBW in 54% (Scond; z-scores> +1.96) and in spirometry FEF25-75 in 44% of participants (z-scores< -1.96). SAD, defined by oscillometry and/or MBW abnormality, occurred in 77%. Among those with abnormal R5-R20, Scond was abnormal in 71%. Correlations indicated both R5-R20 and Scond were linked to asthma medication burden, baseline FEV1 and reversibility. Additionally, Scond correlated with FENO and magnitude of bronchial hyper-responsiveness. SAD, detected by oscillometry and/or MBW, occurred in almost 80% of school-aged asthmatic children, surpassing FEF25-75 detection rates.
UNASSIGNED: Discordant oscillometry and MBW abnormality suggests they reflect different aspects of SAD, serving as complementary tools. Key asthma clinical features, like reversibility, had stronger correlation with MBW-derived Scond than oscillometry-derived R5-R20.