冷空气激发前后运动性哮喘患者外周气道功能的变化

Change in Peripheral Airway Function after Cold Air Airway Provocation in Patients with Exercise-induced Asthma

目的:分析运动性哮喘(EIA)患者过度通气冷空气后FEV1和脉冲震荡肺功能(IOS)指标的变化,探讨外周气道病变在EIA发病中的作用。方法:EIA组20例,35.8±10.3岁,男11例,女9例;健康对照组10例,33.0±8.3岁,男女各5例。按照入选和排除标准选取研究对象,签署知情同意书后进入试验。受试者先行IOS和常规肺功能测定。然后行冷空气气道激发试验,在过度通气冷空气结束后第5、10、15、20、30分钟分别行常规肺功能检测(FEV1等)和IOS检测(R20、R5-R20等),以冷空气激发后FEV1下降≥10%作为冷空气激发试验阳性标准,计算激发前后中心气道阻力变化(ΔR20)和外周气道阻力变化[Δ(R5-R20)]。结果:(1)EIA组与健康对照组受试者在冷空气激发试验中达到的分钟通气量无明显差异;EIA组冷空气激发后FEV1降低百分比显著高于健康对照组;EIA组中有15例(占75%)患者冷空气激发试验阳性,健康对照组有1例(占10%)阳性。(2)冷空气激发试验前,EIA组受试者R5-R20显著高于健康对照组,而两组间R20无显著性差异。冷空气激发试验前后对比,激发后EIA组R5-R20、R20均较激发前显著升高;健康对照组激发后R5-R20较激发前显著升高,而R20无明显变化。冷空气激发后EIA组受试者Δ(R5-R20)与ΔR20相比差异显著,健康对照组受试者ΔR20和Δ(R5-R20)相比无显著差异。结论:冷空气激发试验对于EIA是一种敏感的辅助诊断方法;EIA患者普遍存在外周气道病变,稳定期患者中心气道阻力接近正常,而其外周气道阻力仍高于正常;EIA患者激发试验时外周气道反应强于中心气道,外周气道病变在EIA的发病中发挥着重要作用。

Objective To observe the change in FEV1 and the index of impulse oscillometry（IOS）,such as R5 and R5-R20 after hyperventilating cold air in patients with exercise-induced asthma（EIA）,and the role of peripheral airway affections in the onset of atopic asthma.Methods The subjects included an EIA group（n=20,11 males and 9 females,aged 35.8±10.3 years）and a control group（n=10,5 males and 5 females,aged 33.0±8.3 years）.All subjects underwent the examination of IOS（R20,R5-R20）and lung function（FEV1）in 5min,10min,15min,20min and 30min after the cold air provocation.Decreased FEV1 by at least 10% was used as positive criterion of cold air provocation.The changes in peripheral airway resistance [Δ（R5-R20）] and in central airway resistance（ΔR20）after cold air provocation were calculated.Results（1）There was no significant variance in minute ventilation in the test of cold air provocation between the EIA and control groups.The percentage of FEV1 in EIA group significantly decreased comparing to that in control group.15 positive cases of cold air provocation（75%）in group of EIA and 1（10%）in control group were found.（2）R5-R20 was significantly higher in EIA group than in control group before cold air provocation with no significant variance in R20 between the two groups.R5-R20 and R20 in EIA group significantly increased after provocation,as compare to that before cold air provocation,however,only R5-R20 increased significantly after provocation in control group.There was significant difference between Δ（R5-R20）and ΔR20 after provocation in EIA group,and without significant variance between Δ（R5-R20）and ΔR20 in the control group.Conclusions The cold air provocation test is a sensitive auxiliary method for diagnosing EIA.The response of the peripheral airway to cold air provocation was stronger than the central airway in patients with EIA,suggesting that the peripheral airway lesions plays an important role in the development of EIA.