脉冲振荡法测定支气管哮喘患者呼吸阻抗

目的探讨脉冲振荡技术（ＩＯＳ）法测定支气管哮喘患者呼吸阻抗的价值。方法对７４例支气管哮喘患者进行呼吸阻抗的测定并与肺通气功能指标相比较。结果哮喘组共振频率（Ｆｒｅｓ）、５Ｈｚ和２０Ｈｚ振荡频率时粘性阻力（Ｒ５、Ｒ２０）及５Ｈｚ和２０Ｈｚ振荡频率时粘性阻力差值（Ｒ５－Ｒ２０）均明显高于健康组。５Ｈｚ振荡频率时电抗（Ｘ５）明显低于健康组。哮喘组Ｆｒｅｓ、Ｒ５－Ｒ２０、Ｒ５和Ｘ５与用力呼气流速容量曲线参数相关，Ｒ２０与用力呼气流速容量曲线参数不相关。Ｆｒｅｓ与第１秒用力呼气容积和最大呼气流速相关性最密切，相关系数分别为－０．７１４和－０．７２４。Ｆｒｅｓ、Ｒ５－Ｒ２０、Ｒ５和Ｘ５诊断哮喘的敏感性分别为８３．７８％、６７．５７％、５６．７６％和４０．５４％。特异性分别为８６．２１％、８９．６６％、９８．２７％和９４．８３％。结论Ｆｒｅｓ是ＩＯＳ参数中诊断哮喘的最敏感指标。ＩＯＳ是诊断哮喘、判断病情轻重的一个有用工具，值得临床推广使用。

Respiratory Impedance Measured by Impulse Oscillometry in Patients with Bronchial Asthma

Purpose To study the significance of measuring the respiratory impedance in bronchial asthma patients by impulse oscillometry method. Methods The impedance of the respiratory system was measured and compared with pulmonary ventilation function in 74 patients with bronchial asthma. Results There was a significant increase in viscidity resistance at 5 Hz and 20 Hz and the difference between them in the asthma group as compared with that of the healthy group.Reactance at 5 Hz in the bronchial asthma group was markedly lower than that in the healthy group.Resonant frequency,the difference of R 5 and R 20 ,and R 5 and X 5 correlated significantly with the selected parameters of the forced expiratory flow volume curve.No correlation was found between R 20 and forced expiratory flow volume parameters.Close correlation was found between Fres and FEV 1 and between Fres and V max , and the correlation coefficient values were -0.714 and -0.724 respectively.The sensitivity of resonant frequency,R 5-R 20 , R 5 and X 5 for the diagnosis of asthma was 83.78%,67.57%,56.76% and 40.54% respectively.The specificity of them was 86. 21%,89.66%,98.27% and 94.83% respectively. Conclusions Resonant frequency is the most sensitive index of IOS parameters for the diagnosis of bronchial asthma.IOS is a useful tool in diagnosing asthma and determining the patients'condition.It is worthful in clinical use.