Time dependence of recruitment and derecruitment in the lung: a theoretical model
Time dependence of recruitment and derecruitment in the lung: a theoretical model
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DOI：
10.1152/japplphysiol.01274.2001
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发表时间：
2002-08-01
影响因子：
3.3
通讯作者：
Irvin, CG
中科院分区：
文献类型：
--
作者：
Bates, JHT;Irvin, CG
在肺损伤中，肺内空气空间的募集和排出(R/D)显著增强，被认为是导致机械通气期间损伤加剧的原因。有证据表明，R/D是一种依赖时间的现象。我们开发了一个由平行排列的呼吸道和肺泡单位组成的肺的计算机模型。每个气道都有一个临界压力(Pcrit)，高于该临界压力(Pcrit)，它往往打开，低于该临界压力(Pcrit)，它往往关闭，但其速率由压力与Pcrit的距离决定。通过适当的Pcrit分布和R/D速度特性，该模型能够生成从最初的脱气状态充气的肺的真实的第一和第二压力-体积曲线。该模型还预测，在深度充气后，肺弹性将短暂增加，达到随着肺体积减少和肺损伤而增加的程度。我们的结论是，我们的模型捕捉到了由于肺单位逐渐R/D而导致的肺的时间依赖的机械行为。
Recruitment and derecruitment (R/D) of air spaces within the lung is greatly enhanced in lung injury and is thought to be responsible for exacerbating injury during mechanical ventilation. There is evidence to suggest that R/D is a time-dependent phenomenon. We have developed a computer model of the lung consisting of a parallel arrangement of airways and alveolar units. Each airway has a critical pressure (Pcrit) above which it tends to open and below which it tends to close but at a rate determined by how far pressure is from Pcrit. With an appropriate distribution of Pcrit and R/D velocity characteristics, the model able to produce realistic first and second pressure-volume curves of a lung inflated from an initially degassed state. The model also predicts that lung elastance will increase transiently after a deep inflation to a degree that increases as lung volume decreases and as the lung becomes injured. We conclude that our model captures the time-dependent mechanical behavior of the lung due to gradual R/D of lung units.