脉冲振荡法对气道反应性测定的诊断标准初探

Implication of impulse oscillometry in the measurement of bronchial hyperresponsiveness

目的以肺通气功能进行支气管激发试验的方法作为“金标准”,探讨脉冲振荡法肺功能测定(IOS)对气道反应性测定的可行性及诊断标准。方法对50例门诊哮喘疑诊患者进行组织胺支气管激发试验,于基础状态及每次吸药激发后,先用IOS法测定呼吸道阻力各主要指标:共振频率(Fres)、呼吸总阻抗(Zrs)、呼吸道总黏性阻力(R5)、中心气道黏性阻力(R20)、周边气道黏性阻力(R5-R20)、周边弹性阻力(X5)、中心阻力(Rc)、周边阻力(Rp),然后进行肺通气功能检测,测定第1秒用力呼气量(FEV1)。结果气道高反应性的阳性率为70%。在激发试验终止时,阴性组IOS各阻力较基础值变化差异无统计学意义(P>0.05),而阳性组IOS各阻力除Rc外均较基础值增加(P<0.05)。各IOS阻力指标与FEV1均呈显著的直线相关关系(P<0.05),除X5呈正相关外,余均呈负相关。Fres、Zrs、R5、X5、Rp的增加率与FEV1下降率间存在直线关系(P<0.05)。激发试验终止时,Fres、Rp增加80%或Zrs、R5增加50%或X5增加1倍,可作为IOS法气道高反应性阳性判断标准。结论IOS法可作为气道反应性测定另一可选择的肺功能测定方法,Fres是IOS法各参数中用于诊断气道高反应性敏感性及特异性最高的指标。

Objective To explore the feasibility and diagnostic criteria of impulse oscillometry （lOS） in the measurement of bronchial hyperresponsiveness（BHR）, and compare with the routine spirometry method which acts as a ＂gold standard＂. Methods Fifty suspect asthmatic outpatients were selected randomaly to perform bronchial challenge test with lOS and spirometry respectively. Several parameters of airway resistance, including Fres, Zrs, Rc, Rp, R5, R20, X5 as well as FEV1, were measured before and after each challenge with Histamine. Results Positive rate of BHR was 70 %. At the final challenge test, all parameters of lOS were not significantly changed compared with baseline （P〉0.05） in the negative group. However, there was a significant increase in each parameter except Rc in the positive group （P〈0.05）. Close linear correlation was found between all resistant parameters and FEV1 （P 〈 0. 001）. Meanwhile, there was linear correlation between the increasing rate of Fres, Zrs, R5,X5, Rp and the decreasing rate of FEV1 （P〈0.05）. The diagnostic criteria of BHR was that Fres,Rp increased by 80 % or Zrs, R5 increased by 50 % or X5 by a double at the final test. Conclusions Impulse oscillometry is an alternative method for bronchial hyperresponsiveness measurement. Resonance frequency is the most sensitive and specific index of lOS parameters for the diagnosis.