Astograph法激发试验及小气道功能指标诊断哮喘的价值

The value of Astograph provocation test and small airway function index in the diagnosis of asthma

目的探讨Astograph法激发试验及小气道功能指标诊断哮喘的价值。方法纳入2018年1月至2019年3月就诊于三家医院的哮喘患者86例,并以40例非哮喘患者作为对照组。受试者依次完成基本资料采集、脉冲震荡检查、肺常规通气功能、Astograph法激发试验。比较哮喘组与非哮喘组常规肺功能指标、脉冲振荡指标、反应阈值(Dmin),并分析各指标间的相关关系。结果哮喘组Dmin、用力呼气50%肺活量(余50%肺活量)的瞬间流量(MEF50)、用力呼气75%肺活量(余25%肺活量)的瞬间流量(MEF25)、最大呼气中段流速(MMEF)低于非哮喘组(P<0.05)。哮喘组与非哮喘组呼吸总阻抗(Zrs)、总气道阻力(R5)、中心气道阻力(R20)、外周阻力(R5-R20)、外周弹性阻力(X5)、共振频率(Fres)比较差异无统计学意义(P>0.05)。哮喘患者的Dmin与MEF50、MEF25、MMEF呈正相关(r=0.295、0.306、0.381,均P<0.05)。Dmin诊断哮喘的曲线下面积(AUC)为0.978(95%CI:0.950~1.000),最佳截断值为13.609 Units,灵敏度和特异度分别为0.946和0.968。MEF50、MEF25、MMEF诊断哮喘的曲线下面积分别为0.674,0.738,0.683,最佳截断值分别为3.990 L、1.685 L、3.445 L。结论 Astograph法激发试验快速、安全、准确,适用于协助哮喘诊断。MEF50、MEF25可能与哮喘的诊断有关,能够预测气道高反应性。MMEF、MEF50和MEF25在哮喘的诊断意义优于脉冲振荡指标。

Objective To explore the value of Astograph challenge test and small airway functional parameters to diagnose asthma.Methods 86 asthmatics were enrolled along with 40 non-asthmatic patients as a control group from January 2018 to March 2019 in People′s Hospital of Nanhai Economic Development Zone,Foshan Chancheng District Central Hospital and Affiliated Hospital of Guangdong Medical University.All subjects were required to complete data acquisition,impulse oscillometry(IOS),pulmonary function test,and Astograph challenge test.The routine pulmonary function indexes,pulse oscillation indexes and reaction threshold(Dmin)were compared between asthma group and non asthma group,and the correlation between each index was analyzed.Results The Dmin,max expiratory at 50%forced vital capacity(MEF50%),max expiratory at 75%forced vital capacity(MEF25%),maximal mid expiratory flow(MMEF)of asthma group were significantly lower than those of non-asthmatic group(P<0.05).The IOS parameters such as respiratory impedance(Zrs),resistance at 5 Hz(R5),resistance at 20 Hz(R20),peripheral resistance(R5-R20),reactance at 5 Hz(X5),the resonance frequency(Fres)showed no statistical significance between the asthmatics and the non-asthmatics(P>0.05).Response threshold(Dmin)was positively correlated to MEF50,MEF25 and MMEF respectively(0.295,0.306,0.381,all P<0.05).A receiver operating characteristic(ROC)analysis indicated the area under ROC curve(AUC)of Dmin in diagnosis of asthma was 0.978(95%CI:0.950-1.000),the best cutoff point of Dmin was 13.609 Units,with sensitivity in diagnosing asthma 94.6%,specifity 96.8%.The AUC for MEF50,MEF25,MMEF were 0.674,0.738,0.683,with the best cutoffs 3.990 L,1.685 L,3.445 L,respectively.Conclusions Astograph challenge test,which is fast,safe and precise,can assist in the diagnosis of asthma.MEF50 and MEF25 may be associated with the diagnosis of asthma and can predict airway hyper-responsiveness while IOS parameters could not,which make MMEF,MEF50 and MEF25 superior to IOS parameters in the diagnosis of asthma.