Continuous Monitoring for Cerebral Pressure-Passivity in Premature Infants

项目总结 早产儿的脑损伤是一个巨大的问题， 主要由受扰的脑血管机制调节 未成熟大脑中的血管调节。压力被动是一种主要的表现 脑血管调节紊乱，在缺氧缺血(HI)和 早产儿出血性脑损伤。大脑压力被动发展 当全身血压(BP)不稳定，脑压自动调节 受伤了。我们已经证明了低血压和血液波动 在患病的早产儿中，压力和大脑压力被动是常见的。这个 缺乏持续监测动态的集成床边技术 这些信号之间识别大脑压力被动的关系受阻 制定合理的BP管理策略预防脑部疾病 早产儿的损伤。我们已经开发了这样一个系统，它可以测量 连续脑近红外光谱(NIRS)和血压变化识别 病儿床边的脑压被动周期。我们测量了 系统性血压变化和血压变化之间的一致性(使用传递函数分析 大脑近红外血红蛋白差值(HBD)信号；然后我们得出压力被动 指数(PPI)，以量化随时间推移的压力被动性。在这项研究中提出 在这里，我们的目标是开始验证通过测量大脑压力被动的能力 我们识别即将发生的生发基质-脑室出血(GM-IVH)的技术 由每4小时一次的美国“侦察”研究检测到。此外，我们将努力定义特征 易受压力被动影响的全身性血压和二氧化碳水平。如果经过验证，这 该方法将为生物医学和临床研究的发展带来巨大的好处 而最重要的是最终会导致理性人脑的发展 血流动力学管理，防止早产儿毁灭性的脑损伤。 因此，这里提出的工作完全是为了最大限度地利用这一机会 极易受伤害的人群，以实现其健康和富有成效的生活的潜力 不受疾病或残疾的阻碍。

PROJECT SUMMARY Brain injury in the preterm infant is a problem of enormous magnitude and is mediated largely by cerebrovascular mechanisms emanating from disturbed vasoregulation in the immature brain. Pressure passivity is a major manifestation of disturbed cerebral vasoregulation and is pivotal in both hypoxic-ischemic (HI) and hemorrhagic brain injury in premature infants. Cerebral pressure passivity develops when systemic blood pressure (BP) is unstable and cerebral pressure autoregulation is impaired. We have demonstrated that hypotension, as well as fluctuations in blood pressure and cerebral pressure passivity are common in sick premature infants. The lack of an integrated bedside technique that continuously monitors the dynamic relationship between these signals to identify cerebral pressure-passivity has impeded the formulation of rational strategies for BP management aimed at preventing brain injury in the preterm infant. We have developed such a system that measures continuous cerebral near infrared spectroscopy (NIRS) and BP changes to identify periods of cerebral pressure passivity at the bedside of sick infants. We measure the coherence (using transfer function analysis) between changes in systemic BP and the cerebral NIRS hemoglobin difference (HbD) signal; we then derive a pressure-passive index (PPI) in order to quantify pressure passivity over time. In the research proposed here, we aim to begin validating the ability of cerebral pressure passivity measured by our technique to identify imminent germinal matrix-intraventricular hemorrhage (GM-IVH) detected by 4-hourly `scout' US studies. In addition, we will seek to define characteristics of systemic BP and CO2 levels that predispose to pressure passivity. If validated, this approach will have enormous benefit for the advance of biomedical and clinical research and most importantly will lead to the eventual development of rational brain-oriented hemodynamic management that prevents the devastating brain injuries of prematurity. As such the work proposed here is squarely directed at maximizing opportunities for this extremely vulnerable population to fulfill their potential for a healthy and productive life unhampered by disease or disability.