[哮喘儿童乙酰甲胆碱支气管吸入激发试验中气管听诊与肺功能的一致性]

de Frutos Martínez C, González Pérez-Yarza E, Aldasoro Ruiz A, Emparanza Knörr J I, Callén Blecua M, Mintegui Aramburu J

Unidades de Neumología Infantil.Hospital Donostia, San Sebastián, Spain.

An Esp Pediatr. 2002 Apr;56(4):304-9.

BACKGROUND

PC wheezing (PCw) is defined as the concentration of methacholine at which wheeze is detected on auscultation of the trachea. PCw has been suggested as a measure of bronchial hyperresponsiveness in methacholine challenge testing (MCT).

OBJECTIVE

The aim of this study was to determine the agreement between the concentration of methacholine that produces a 20 % decrease in forced expiratory volume in 1 second (FEV1) (PC20) and PCw in MCT in asthmatic children.

PATIENTS AND METHODS

Eighteen asthmatic children with a mean age of 11.5 years (range: 6-16 years) were studied. Fifteen of the children were under treatment with inhaled glucocorticoids. MCT was performed according to the guidelines of the American Thoracic Society (1999) using a Hudson nebulizer calibrated to obtain a mean output of 0.14 ml/min. After each nebulization, two independent observers registered FEV1 and tracheal auscultation. FEV1 was determined by forced spirometry 30 and 90 seconds after the end of nebulization and PC20 was registered (exponential model). Respiratory rate and transcutaneous oxygen saturation were continuously monitored. Tracheal auscultation was performed at 0, 60 and 120 seconds after the end of nebulization. The end point was defined as the appearance of wheezing over the trachea. The values of PC20 and PCw, as well as the concentration of methacholine corresponding to a decrease in FEV1 equal to or higher than 20 %, were compared using Student's matched pairs-test and Wilcoxon's test. The degree of agreement between variables was compared by using Bland-Altman's test.

RESULTS

MCT was positive in 17 of 18 patients. No differences were found between PC20 and PCw (p 0.15). Both variables showed agreement in 12 of 17. A clear association was found between both measures (log PCw, log PC20): R: 0.92; p < 0.001. The mean decrease in FEV1 on reaching PCw was 24.8 % (range: 10-41). No adverse effects were observed.

CONCLUSION

The agreement between PC20 and PCw in MCT in asthmatic children is excellent. PCw could be helpful in determining bronchial hyperresponsiveness in young asthmatic children in whom spirometry is not feasible.

背景

激发试验中气管哮鸣音出现时的乙酰甲胆碱浓度定义为激发试验哮鸣音浓度（PCw）。PCw已被提议作为乙酰甲胆碱激发试验（MCT）中支气管高反应性的一项指标。

目的

本研究旨在确定哮喘儿童MCT中使一秒用力呼气容积（FEV1）下降20%的乙酰甲胆碱浓度（PC20）与PCw之间的一致性。

患者和方法

研究了18名平均年龄11.5岁（范围：6 - 16岁）的哮喘儿童。其中15名儿童正在接受吸入糖皮质激素治疗。MCT按照美国胸科学会（1999年）的指南进行，使用校准后平均输出为0.14 ml/min的Hudson雾化器。每次雾化后，两名独立观察者记录FEV1和气管听诊情况。雾化结束后30秒和90秒通过用力肺活量测定法测定FEV1并记录PC20（指数模型）。持续监测呼吸频率和经皮血氧饱和度。雾化结束后0、60和120秒进行气管听诊。终点定义为气管出现哮鸣音。使用配对t检验和Wilcoxon检验比较PC20和PCw的值，以及与FEV1下降等于或高于20%相对应的乙酰甲胆碱浓度。使用Bland - Altman检验比较变量之间的一致性程度。

结果

18例患者中有17例MCT呈阳性。PC20和PCw之间未发现差异（p > 0.15）。17例中有12例两个变量显示出一致性。两种测量方法之间发现明显相关性（log PCw，log PC20）：R：0.92；p < 0.001。达到PCw时FEV1的平均下降为24.8%（范围：10 - 41）。未观察到不良反应。