Mechanical impedance of the lung periphery
Mechanical impedance of the lung periphery
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DOI：
10.1152/jappl.1997.83.5.1595
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发表时间：
1997-11-01
影响因子：
3.3
通讯作者：
Fredberg, JJ
中科院分区：
文献类型：
--
作者：
Hantos, Z;Petak, F;Fredberg, JJ
通过改进的波管技术，在离体犬肺叶中研究了局部气道和组织的力学。通过插入直径为1 mm的支气管的导管，在每一肺叶的三个区域施加0.1 - 48 Hz的小振幅伪随机强迫振荡，跨叶压（PL）为10、7、5、3、2和1 cmH（2）O。测量的区域输入阻抗通过包含规则（节段性）气道的阻力（R-1）和惯性（I）、侧支通道的阻力（R-2）以及局部组织的阻尼（G）和弹性（H）的模型来拟合。该模型比用单一组织顺应性代替CT和H时更好地拟合肺外周阻抗数据，这解释了为什么在先前研究中节段性血流中断不会导致单指数压力衰减。参数的叶间和叶内方差同样显著，并且在气道参数R-1和R-2之间以及在任何气道和组织参数（例如，R-1和H）。R-2平均比R-1高10倍，尽管R-2与R-1的比率及其对PL的依赖性在区域上高度可变。然而，对于研究的总共33个区域，R-1和R-2的PL依赖性是相同的，这可能反映了规则气道和侧支气道的相似形态结构。G和H对PL的依赖性表现出很高的区域间差异;然而，一般来说，它们在中等PL值（类似于5 cmH（2）O）时达到最小值。
The mechanics of the regional airways and tissues was studied in isolated dog lobes by means of a modified wave-tube technique. Small-amplitude pseudorandom forced oscillations between 0.1 and 48 Hz were applied through catheters wedged in a-mm-diameter bronchi in three regions of each lobe at translobar pressures (PL) of 10, 7, 5, 3, 2, and 1 cmH(2)O. The measured regional input impedances were fitted by a model containing the resistance (R-1) and inertance (I) of the regular (segmental) airways, the resistance of the collateral channels (R-2), and the damping (G) and elastance (H) of the local tissues. This model gave far better fits to the data on impedance of the lung periphery than when CT and H were replaced by a single tissue compliance, which explains why interruption of segmental flow did not lead to monoexponential pressure decay in previous studies. The interlobar and intralobar variances of the parameters were equally significant, and poor correlations were found between the airway parameters R-1 and R-2 and between any airway and tissue parameter (e.g., R-1 and H). R-2 was On average similar to 10 times higher than R-1, although the R-2-to-R-1 ratios and their dependencies on PL were regionally highly variable. However, for the total of 33 regions studied, the PL dependence was the same for R-1 and R-2, which may reflect similar morphological structures for the regular and collateral airways. The dependencies of G and H on PL showed high interregional variations; generally, however, they assumed their minima at medium PL values (similar to 5 cmH(2)O).