Department of Pediatric Pulmonology and Allergy, Children's Hospital, Goethe-University, Theodor Stern Kai 7, 60590 Frankfurt am Main, Germany.
Respir Med. 2009 Dec;103(12):1898-903. doi: 10.1016/j.rmed.2009.06.007. Epub 2009 Jul 10.
Bronchial methacholine challenge is well established in asthma diagnostics and research. ATS guidelines propose a five step standard dosimeter (SDM) protocol with incremental concentrations of methacholine to calculate the concentration causing a 20% drop in FEV(1) in an individual (PC(20)FEV(1)). In contrast, the aerosol provocation system (APS) by Viasys automatically determines the administered dose of methacholine by measuring the effective nebulisation time and referring it to drug concentration and nebuliser power. Therefore, it offers a feasible and less time-consuming provocation procedure by applying incremental doses (PD(20)) of methacholine using a single concentration (16mg/mL methacholine, APS-SC). In this study we compared these two methods in 52 young adults (25+/-5.8 years). Following a screening visit, subjects were randomly assigned to undergo either SDM or APS-SC followed by the other method within 1 week. A close correlation between concentration and dosage causing a 20% fall of FEV(1) was found (r=0.69, p<0.001). Using the ATS categorisation of bronchial responsiveness we interpreted the results of the APS-SC method as follows: PD(20) methacholine<0.3mg as "moderate to severe BHR", 0.3 - 0.6mg as "mild BHR", 0.6 - 1.0mg as "borderline BHR", and>1.0mg as "normal bronchial response". We conclude that the five-step APS-SC is a suitable method, providing reliable results. In clinical practice the APS-SC is a timesaving procedure and less prone to errors since only one dilution of methacholine is necessary compared to the SDM.
气道乙酰甲胆碱挑战在哮喘诊断和研究中得到了很好的应用。ATS 指南提出了一个五步标准剂量计（SDM）方案，使用递增浓度的乙酰甲胆碱来计算个体中引起 FEV1 下降 20%的浓度（PC20FEV1）。相比之下，Viasys 的气溶胶激发系统（APS）通过测量有效雾化时间，并参考药物浓度和雾化器功率，自动确定乙酰甲胆碱的给药剂量。因此，它通过使用单个浓度（16mg/mL 乙酰甲胆碱，APS-SC）递增剂量（PD20）的方法提供了一种可行且耗时更少的激发程序。在这项研究中，我们比较了这两种方法在 52 名年轻成年人（25+/-5.8 岁）中的应用。在筛选访问后，受试者被随机分配接受 SDM 或 APS-SC，然后在 1 周内接受另一种方法。FEV1 下降 20%的浓度和剂量之间存在密切相关性（r=0.69，p<0.001）。使用 ATS 对支气管反应性的分类，我们将 APS-SC 方法的结果解释为：PD20 乙酰甲胆碱<0.3mg 为“中度至重度 BHR”，0.3-0.6mg 为“轻度 BHR”，0.6-1.0mg 为“边界 BHR”，>1.0mg 为“正常支气管反应”。我们得出结论，五步 APS-SC 是一种可靠的方法，提供可靠的结果。在临床实践中，APS-SC 是一种省时的程序，并且由于与 SDM 相比只需要一种乙酰甲胆碱稀释液，因此不太容易出错。
