缓解期哮喘患儿的小气道功能和气道高反应性的相关性研究

Relationship between small airway function and airway hyper responsiveness in children with asthma

目的测定缓解期哮喘患儿的气道高反应性和小气道功能,探讨气道高反应性与小气道功能及临床缓解时间的相关性。方法选取我院收治的64例缓解期哮喘患儿进行肺功能测定和支气管激发试验(以乙酰胆碱作为激发剂),以第一秒最大呼气量(FEV1)下降≥20%作为阳性诊断标准,比较乙酰胆碱激发试验(MCC)阳性组和阴性组患儿的小气道各项指标的基础值及下降百分率;以患儿临床缓解时间≤12个月和>12个月的时间为依据,比较两组患儿的MCC的阳性率。结果 (1)MCC阳性患者的小气道指标MEF75占预计值、MEF50占预计值以及MEF25占预计值占均显著低于MCC阴性组(P<0.05);(2)MCC阳性组比阴性组各项小气道指标(MEF25、MEF50、MEF75)下降的程度大且速度快(P<0.05);(3)缓解时间>12个月和≤12个月的患儿间支气管激发试验阳性率差异无显著意义(P>0.05);(4)FEV1下降百分率与MEF25下降百分率无显著相关(r=0.435,P=0.125),其余小气道指标与FEV1相关系数均约为0.7(P<0.01)。结论缓解期哮喘患儿依然存在气道炎症,症状缓解时间>12个月的患儿与≤12个月的患儿MCC发生率比较无显著差异。小气道各项指标的基础值及激发试验中、下降百分率与患儿气道高反应性有显著的相关性,具有重要的临床参考价值。

Objective To measure the bronchial hyperresponsiveness and small airway function in children with asthma, and to explore the relationship between bronchial hyperresponsiveness, small airway function and clini- cal remission time. Methods 64 children with asthma were conducted through pulmonary function test and bronchial provocation test （using acetylcholine as activator）. Taking first second maximal expiratory volume （ FEV1 ） decline was more than or equal to 20% as a positive diagnostic criteria, the basic value and decrease percentage of small air-way were compared between the acetylcholine provocation test （MCC） positive group and the negative group. In clini- cal remission time less than 12 months, and 12 months as the basis, the positive rate of MCC was compared between the two groups. Results （ 1 ） The expected value of MEF75, MEFS0 and MEF25 of small airway parameters were significantly higher in the MCC positive group than in the MCC negative group （ P 〈 0. 05 ）. （2） The small airway indexes （MEF25, MEFS0, MEF75） were lower in the MCC positive group than in the negative group, and the decrease was faster （P 〈0. 05）. （3） The remission time 〉 12 months and ≤ 12 months in patients with positive bronchial provocation test showed no significant difference （P 〉0. 05）. （4） The decrease of FEV1 and MEF25 had no obvious correlation, the rest of the small airway indexes and FEV1 had obvious correlation with 0. 7 of efficiency （ P 〈 0. 01 ）. Conclusion Airway inflammation still exists in remission asthmatic children, and there is no significant difference in MCC incidence between relieve symptoms time 〉 12 months and ≤ 12 months. The basic values of various indexes of small airway and the percentage of decrease in the excitation test have significant correlation with air-way high reactivity, which has important clinical reference value.