How heterogeneous bronchoconstriction affects ventilation distribution in human lungs: A morphometric model
How heterogeneous bronchoconstriction affects ventilation distribution in human lungs: A morphometric model
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DOI：
10.1114/1.161
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发表时间：
1999-01-01
影响因子：
3.8
通讯作者：
Lutchen, KR
中科院分区：
文献类型：
--
作者：
Gillis, HL;Lutchen, KR
与腺泡近端气道相关的对流依赖性流量异质性是诱发支气管收缩期间通气分布异常的主要原因（Verbanck, S., D. Schuermans, A. Van Muylem, M. Paira, M. Noppen, and W. Vincken. Ventilation distribution during histamine prospiration. J. Appl. Physiol. 83:1907-1916, 1997）。我们应用人肺形态测量模型来预测异质支气管收缩期间腺泡之间的流量分布，并将这些分布与肺机械特性的损伤相关联。该模型具有不对称分支气道系统。通过定义具有平均值 (mu) 和变异系数 (CV) 以及高斯分布或对数正态分布的气道收缩分布来调用异质收缩。肺阻力（R-L）和弹性（E-L）对严重不均匀收缩最敏感，这种收缩会产生一些随机分散在整个外周的高度收缩或闭合的气道。健康肺部的通气分布在 0.1-5.0 Hz 的频率范围内实际上是均匀的。对于均匀或轻度不均匀收缩（CV 小于或等于 20%），通气在低频（小于或等于 0.1 Hz）时保持相当均匀，但随着频率增加而迅速变得不均匀。相反，产生随机气道关闭的低平均但严重异质性收缩会在所有频率下的大多数腺泡中产生异常通气分布，并且一些腺泡接收的通气量高达正常通气量的 25 倍。这表明，即使在常见的机械通气速率下，某些形式的异质性也可能导致剪切诱发的肺损伤。 (C) 1999 年生物医学工程学会。 [S0090-6964(99)01201-1]。
Convective dependent flow heterogeneities associated with airways proximal to the acini are the dominant cause of abnormal ventilation distribution during induced bronchoconstriction (Verbanck, S., D. Schuermans, A. Van Muylem, M. Paira, M. Noppen, and W. Vincken. Ventilation distribution during histamine provocation. J. Appl. Physiol. 83:1907-1916, 1997). We applied a morphometric model of the human lung to predict flow distributions among the acini during heterogeneous bronchoconstriction and relate these distributions to impairments in the mechanical properties of the lung. The model has an asymmetrical branching airway system. Heterogeneous constriction was invoked by defining an airway constriction distribution with a mean (mu) and coefficient of variation (CV) and either a Gaussian or log normal distribution. The lung resistance (R-L) and elastance (E-L) were most sensitive to severely heterogeneous constriction that produced a few highly constricted or closed airways dispersed randomly throughout the periphery. Ventilation distribution in the healthy lung was effectively homogeneous over the frequency range of 0.1-5.0 Hz. With homogeneous or mildly heterogeneous constriction (CV less than or equal to 20%) ventilation remained fairly homogeneous at low frequencies (less than or equal to 0.1 Hz) but rapidly became heterogeneous as frequency increased. Conversely, a low mean but severely heterogeneous constriction that produced random airway closure produced abnormal ventilation distribution in most acini at all frequencies, and some acini received up to 25 times the normal ventilation. This suggests that certain forms of heterogeneity can lead to shear induced lung injury even at common mechanical ventilation rates. (C) 1999 Biomedical Engineering Society. [S0090-6964(99)01201-1].