Department of Radiology, NorthShore University HealthSystem, Evanston, IL, USA.
Department of Anesthesiology, NorthShore University HealthSystem, Evanston, IL, USA.
Adv Exp Med Biol. 2024;1463:35-39. doi: 10.1007/978-3-031-67458-7_6.
Brain health directly depends on maintaining a level of tissue oxygen that is high enough to avoid global hypoxia and local brain ischaemia. It is well documented that general anaesthesia has an anti-hypoxic neuroprotective effect. Previous studies of this effect primarily assessed the biochemical actions of anaesthetics. Physical actions were not well studied because the quantification of oxygen dynamics has only recently been described. Based on known oxygen, blood, and neuronal measurements, under various anaesthesia protocols and in the awake state, we mathematically analysed physical anaesthesia effects on oxygen distribution for localised hypoxia. From this, we built a universal equation of oxygen dynamics which can be applied to both animal and human subjects in awake and anaesthetised states, under normoxia, hyperoxia, and hypoxia. Using this equation, we determined that a proper anaesthesia protocol can protect up to 167 mm of local hypoxic cortical brain tissue via oxygen diffusion from healthy neighbouring areas.
大脑健康直接取决于维持足够高的组织氧水平，以避免全局缺氧和局部脑缺血。大量文献证明全身麻醉具有抗缺氧神经保护作用。先前对这种作用的研究主要评估了麻醉剂的生化作用。由于最近才描述了氧动力学的定量方法，因此物理作用并未得到很好的研究。基于已知的氧、血液和神经元测量值，我们根据各种麻醉方案和清醒状态下的测量值，从数学上分析了物理麻醉对局部缺氧时氧分布的影响。由此，我们构建了一个通用的氧动力学方程，该方程可应用于清醒和麻醉状态下的动物和人体受试者，以及在正常氧合、高氧合和低氧合情况下。使用这个方程，我们确定一个适当的麻醉方案可以通过来自健康相邻区域的氧气扩散来保护多达 167 毫米的局部缺氧皮质脑组织。
