脉冲振荡法在儿童呼吸道反应性测定中的应用

Application of impulse oscillometry in the measurement for childhood bronchial hyperresponsiveness

目的 探讨脉冲振荡法（IOS）在儿童呼吸道反应性测定中的应用和呼吸道激发试验的阳性判断标准.方法 收集临床疑诊支气管哮喘患儿79例,年龄6～14岁.以乙酰甲胆碱激发后第1秒用力呼气容积（FEV 1）下降20％为阳性判断＂金标准＂,同步测定IOS肺功能各参数变化,包括共振频率（Fres）、呼吸总阻抗（Zrs）、总呼吸道阻力（R5）、中心呼吸道阻力（R20）、5 Hz时电抗值（X5）、低频电抗面积（AX）.以肺通气功能法进行激发试验的结果分为阳性组与阴性组,比较2组IOS参数在激发试验前后的差异及FEV 1变化率与IOS各参数变化率的相关性,确定IOS各参数在呼吸道反应性测定中的阳性判断标准.结果 在79例疑似支气管哮喘患者中,肺通气功能法支气管激发试验阳性组37例,阴性组42例.阳性组和阴性组肺功能各参数基础值比较,差异均无统计学意义（均P〉0.05）.IOS各参数中以Zrs、R5、X5的变化率与肺通气功能法FEV 1的变化率呈正相关（r=0.374、0.310、0.449,均P〈0.05）;单因素受试者工作特征（ROC）曲线下面积X5〉Zrs〉R5;Zrs较基础值上升45.85％,R5较基础值上升45.72％,X5较基础值上升80.74％;多元回归模型中Zrs、R5联合应用判断呼吸道高反应性时的灵敏度和特异度分别为73.0％、81.0％.结论 在激发试验中,IOS和肺通气功能法同样可以用于儿童判断呼吸道反应性.Zrs≥45.85％,或R5≥45.72％,或X5≥80.74％作为测定呼吸道高反应性的阳性标准;或用多元回归方程中Zrs、R5二者联合作为测定呼吸道高反应性阳性标准时,其灵敏度和特异度较高.

Objective To explore the effectiveness of impulse oscillometry（IOS）in airway responsiveness measurement and to find out the positive threshold of IOS for asthma diagnosis. Methods Seventy-nine children aged 6-14 years who had suspicious asthma,were recruited into the study. The positive criteria of the methacholine bron-chial provocation test was a 20% reduction in forced expiratory volume in the first second （FEV 1 ）compared to base-line. Simultaneously measured changes in various parameters of IOS,including resonant frequency（Fres）,impedance at 5 Hz（Zrs）,resistances at 5 and 20 Hz（R5,R20）,reactance at 5 Hz（X5）,and area of reactance（AX）. The results of the challenge test were divided into positive and negative groups according to the pulmonary ventilation function me-thod. The differences between the 2 groups of IOS parameters before and after the challenge test,and the correlation be-tween the change rate of FEV1 and the change rate of IOS parameters were compared,and the positive judgment criteria of IOS parameters in the determination of respiratory responsiveness were determined. Results The positive group of bronchial provocation test had 37 patients and negative group had 42 patients. There was no significant difference in the basic values of parameters between the positive group and the negative group （all P 〉 0. 05）. Changes in Zrs,R5,X5 of IOS were correlated with changes in FEV1 （r = 0. 374,0. 310,0. 449,all P 〈 0. 05）. By single factor analysis,the area under the receiver operating characteristic（ROC）carve （AUC）showed：basic value of Zrs increased by 45. 85%,R5 increased by 45. 72%,X5 increased by 80. 74% respectively compared to the baseline showed the optimal combination of sensitivity and specificity. In multivariate Logistic regression models,when Zrs and R5 were combined to measure the airway responsiveness,the sensitivity and specificity were 73. 0% and 81. 0%,respectively. Conclusions IOS and spirometry can be used to determine airway responsiveness in children during methacholine bronchial challenge. Zrs≥45. 85%,or R5≥45. 72%,or X5≥80. 74%,or Zrs and R5 of multiple regression formula can be used as the positive criteria for young children with airway heperresponsiveness,the combination of Zrs and R5 has higher sensitivity and specificity.