Scott Thomas J A, Jacob Chinthaka, Tingay David G, Leontini Justin S
Department of Mechanical and Product Design Engineering, Swinburne University of Technology, Hawthorn, VIC, Australia.
Laboratoire de Physique, ENSL, CNRS, F-69342 Lyon, France.
Respir Res. 2024 Dec 28;25(1):446. doi: 10.1186/s12931-024-03049-w.
By virtue of applying small tidal volumes, high-frequency ventilation is advocated as a method of minimizing ventilator-induced lung injury. Lung protective benefits are established in infants, but not in other patient cohorts. Efforts to improve and extend the lung protection potential should consider how fundamental modes of gas transport can be exploited to minimize harmful tidal volumes while maintaining or improving ventilation.This research investigates different models of gas transport during high-frequency ventilation and discusses the extent to which the gas transport mechanisms are considered in each. The research focuses on the rationale for current ventilation protocols, how they were informed by these models, and investigates alternative protocols that may improve gas transport and lung protection. A review of high-frequency ventilation physiology and fluid mechanics literature was performed, and dimensional analyses were conducted showing the relationship between clinical data and the model outputs. We show that contemporary protocols have been informed by resistor-inductor-capacitor, or network, models of the airway-lung system that are formulated around a ventilation pressure cost framework. This framework leads to clinical protocol selection that ventilates patients at frequencies that excite a resonance in the lung. We extend on these models by considering frequencies that are much higher than resonance which further optimize gas transport in the airway via alternative gas transport mechanisms to bulk advection that operate for very low tidal volumes. Our findings suggest it is unlikely that gas transport is optimally exploited during current approaches to high-frequency ventilation and protocols that differ significantly from those currently in use could achieve ventilation while using very low tidal volumes.
凭借应用小潮气量，高频通气被倡导为一种将呼吸机诱导的肺损伤降至最低的方法。肺保护益处已在婴儿中得到证实，但在其他患者群体中尚未得到证实。为提高和扩展肺保护潜力所做的努力应考虑如何利用基本的气体传输模式，在维持或改善通气的同时尽量减少有害的潮气量。本研究调查了高频通气期间不同的气体传输模型，并讨论了每种模型中气体传输机制的考虑程度。该研究重点关注当前通气方案的原理、这些模型如何为其提供信息，并研究可能改善气体传输和肺保护的替代方案。对高频通气生理学和流体力学文献进行了综述，并进行了量纲分析，以显示临床数据与模型输出之间的关系。我们表明，当代方案是基于围绕通气压力成本框架制定的气道-肺系统的电阻-电感-电容或网络模型。这个框架导致临床方案选择以激发肺部共振的频率对患者进行通气。我们通过考虑远高于共振频率的频率来扩展这些模型，这通过替代气体传输机制进一步优化气道中的气体传输，以实现非常低的潮气量下的大量平流。我们的研究结果表明，在当前的高频通气方法中，气体传输不太可能得到最佳利用，与当前使用的方法有显著差异的方案可以在使用非常低的潮气量的情况下实现通气。
