脉冲振荡肺功能在不同年龄儿童支气管舒张试验中的应用探讨

目的 探讨使用脉冲振荡肺功能(IOS)在支气管舒张试验中的应用价值以及年龄因素对支气管舒张试验阳性判定值的影响.方法 215例哮喘急性发作期患儿,根据年龄分三组(4～7岁组136例、8～11岁组64例、12～16岁组15例).同时测定最大呼气流量-容积(MEFV)和IOS,并进行支气管舒张试验,IOS测定指标包括:呼吸阻抗(Zrs)、气道总阻力(R5)、中心气道阻力(R20)、响应频率(Fres)、5Hz时的弹性阻力(X5).MEFV参数选用反映总气道功能的第1秒用力呼气容积(FEV1).分别比较各组IOS各主要指标改善率与FEV1改善率的关系.结果 吸入支气管舒张剂后各年龄组Fres、Zrs、H5、X5、R20均得到改善,以X5改善最明显,R20降低最少.Frcs、Zrs、R5三组比较差异有统计学意义(P＜0.01),说明三者存在年龄因素影响.而X5与年龄关系不大(P＞ 0.05).结论 IOS可作为儿童支气管舒张试验阳性判断指标的一种选择,适用于儿童和重症者.

Clinical application of impulse oscillation system determining bronchodilator reversibility test in the children of different ages

Objective To explotr clinical application of impulse oscillation system(IOS)determining bronchodilator reversibility test and the impact of age factor on positive values of bronchoddilator reversibility test in children.Methods Two hundred and fifteen patients during asthma attack were recruited randomly for this study.They were divided into three groups according to their age(4-7 year-old group,8-11 year-old group and 12-16 year-old group).Mensurated MEFV and IOS lung function.Carried on the bronchial dilation test with the results.Forced expiratory volume in first second(FEV1),the sensitivity and specificity of IOS parameters,total respiratory impedance(Zrs),respiratory resistance at 5 Hz(R5)and 20 Hz(R20),reactance at 5 Hz(X5)and resonant frequency(Fres)for diagnosing asthma at different improvement levels after inhalation of bronchedilator were calculated respectively through using FEV1 as a "sold standard"in the different age groups.Results After inhalation of bronchodilator,Fres,Zrs,R5,X5 and R20 of IOS were improved significantly.The improvement of X5 was the most obvious,however the decline of R20 was the lowest.The improving rate of Fres,Zrs,R5 had very significant difference in the three age groups(P＜0.01).It displayed that the age factor was very important impact factor on the improving rate of Fres,Zrs,R5,however the improving rate of X5 was on difference in the three age groups(P＞0.05).In the three age groups,there were significantly positive correlations between X5,R5,Zrs and FEV1(P＜0.01).there wash't correlations between R20 and FEV1 in the 4-7 year-old group and the 12-16 year-old group(P＞0.05).Furthermore,when an increase of FEV1 equaling to or greater than 15% was used as reference for positive bronchial reversibility,the improve rate of Fres,Zrs,R5,and X5 equaled to or greater than 13%,23%,17%,31%,respectively in 4-7 year-old group,18%,26%,25%,32%,respectively in 8-11 year-old group,25%,28%,28%,36%,respectively in 12-16 year-old group. Conclusions IOS can be used to assess bronchodilator reversibility test in children,and age factors should be paid attention.