New assessment of small and large airway responsiveness to inhalation aerosol

为了研究小气道和大气道对吸入气溶胶的反应性的作用，我们开发了一种新的系统，该系统连续测量肺阻力（R1）和动态顺应性的频率依赖性（Cdyn. f.），通过对单次呼吸循环中的流量和跨肺压力进行傅立叶级数分析计算。R1是从基波中得到的。根据从基波到第三谐波获得的线性回归线计算了Cdyn.f，并获得了0.5 Hz时的Cdyn（&lt;C_（0.5）&gt;）和0 Hz时的Cdyn（<C_0>）。在室内粉尘变应原吸入中，我们观察到部分哮喘患者R1无明显变化，<C_0>但&lt;C_（0.5）&gt;<C_0>和&lt;C_（0.5）&gt;先降低后升高。部分哮喘患者吸入兴奋剂后<beta_2>，<C_0>R1降至最低值后，&lt;C_（0.5）&gt;仍继续升高。这些结果意味着小气道对室内粉尘气溶胶的反应可能早于大气道的反应，并且<beta_2>刺激性气溶胶可能首先扩张大气道，然后继续扩张小气道。此外，我们研究了使用激光散射方法测量气道中的气溶胶沉积量。然而，我们还不能建立连续的测量量的气溶胶沉积在气道在两年。需要进一步研究。

To examine the role of small and large airway responsiveness to inhalation aerosols, we developed a new system which continuously measures both pulmonary resistance (R1) and frequency dependence of dynamic compliance (Cdyn.f.), calculated by Fourier-series analysis of flow and transpulmonary pressure in a single-cycle of breathing. R1 was obtained from fundamental harmonics. Cdyn.f was calculated from the linear regression line obtained from the fundamental to the third hermonics, and Cdyn at 0.5 Hz ( <C_(0.5)> ) and Cdyn at 0 Hz ( <C_0> ) were obtained. In house dust allergen inhalation, we observed that in some asthmatic patients the decrease in <C_0> and <C_(0.5)> preced the increase in R1 or <C_0> and <C_(0.5)> decreased progressively even if R1 did not change significantly. In some asthmatic subjects, after <beta_2> stimulant aerosol inhalation <C_0> and <C_(0.5)> continued to increase even after R1 decreased to minimum value. These results mean that small airway response to house dust aerosol may be earlier than the large airway response, and that <beta_2> stimulant aerosol may first dilate the large airway and then continue to dilate the small airways. Furthermore, we studied measurement of the amount of aerosol deposition in the airways using a laser scattering method. However, we could not yet establish the continuous measurement of the amount of aerosol deposition in the airways during two years. Further studies are needed.