Airway Transmural Pressures in an Airway Tree During Bronchoconstriction in Asthma.
Airway Transmural Pressures in an Airway Tree During Bronchoconstriction in Asthma.
复制标题
哮喘支气管收缩期间气道树中的气道跨壁压力。
DOI：
10.1115/1.4042478
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Winkler,Tilo
中科院分区：
文献类型：
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作者：
Winkler,Tilo
气道扩张的健康均匀肺的气道跨壁压力大致等于腔内压力和胸膜压力之差。然而，支气管收缩导致气道狭窄、实质扭曲、动态过度充气和通气缺陷（VDefs）的出现，影响跨壁压力。本研究旨在探讨支气管树缩窄引起的跨壁压力变化。使用支气管收缩的综合计算模型估计支气管收缩之前和期间的跨壁压力。简而言之，该模型包含了一个12代对称支气管树，以及该树的单个气道的Anafi和Wilson模型。支气管收缩导致vdef的出现，与基线相比，峰值跨壁压力相对增加高达84%。在VDefs外的中央气道中，峰值跨壁压力的增加最高，而在VDefs内的气道中，最低的增加为27%，说明了支气管树内峰值跨壁压力的异质性。导致跨壁压力峰值增加的机制包括局部通气增加和动态恶性通货膨胀，两者都导致肺泡压力比基线增加。气道阻力增加导致腔内和肺泡压力差增大，其对全壁压力的贡献高达24%。综上所述，与健康均质肺扩张气道相比，支气管收缩时VDefs肺的跨壁压力峰值可显著增加，且高度不均匀。进一步的见解将取决于考虑到这些条件的实验研究。
Airway transmural pressure in healthy homogeneous lungs with dilated airways is approximately equal to the difference between intraluminal and pleural pressure. However, bronchoconstriction causes airway narrowing, parenchymal distortion, dynamic hyperinflation, and the emergence of ventilation defects (VDefs) affecting transmural pressure. This study aimed to investigate the changes in transmural pressure caused by bronchoconstriction in a bronchial tree. Transmural pressures before and during bronchoconstriction were estimated using an integrative computational model of bronchoconstriction. Briefly, this model incorporates a 12-generation symmetric bronchial tree, and the Anafi and Wilson model for the individual airways of the tree. Bronchoconstriction lead to the emergence of VDefs and a relative increase in peak transmural pressures of up to 84% compared to baseline. The highest increase in peak transmural pressure occurred in a central airway outside of VDefs, and the lowest increase was 27% in an airway within VDefs illustrating the heterogeneity in peak transmural pressures within a bronchial tree. Mechanisms contributing to the increase in peak transmural pressures include increased regional ventilation and dynamic hyperinflation both leading to increased alveolar pressures compared to baseline. Pressure differences between intraluminal and alveolar pressure increased driven by the increased airway resistance and its contribution to total transmural pressure reached up to 24%. In conclusion, peak transmural pressure in lungs with VDefs during bronchoconstriction can be substantially increased compared to dilated airways in healthy homogeneous lungs and is highly heterogeneous. Further insights will depend on the experimental studies taking these conditions into account.