Continuous Monitoring for Cerebral Pressure-Passivity in Premature Infants

项目摘要 早产儿的脑损伤是一个巨大的问题， 主要由脑血管机制介导， 未成熟大脑的血管调节压力被动是一个主要的表现， 脑血管调节紊乱，在缺氧缺血性（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，脑压自动调节功能 受损我们已经证明低血压以及血液中的波动 压力和脑压力被动在患病的早产儿中是常见的。的 缺乏连续监测动态的综合床边技术 这些信号之间的关系，以确定大脑的压力被动阻碍了 制定合理的BP管理策略， 早产儿的伤害。我们开发了这样一个系统， 连续脑近红外光谱（NIRS）和血压变化，以确定 在病儿床边的脑压被动期。我们测量 系统性BP变化与血压变化之间的一致性（使用传递函数分析） 脑NIRS血红蛋白差异（HbD）信号;然后，我们推导出压力被动 指数（PPI），以量化压力随时间的被动性。在这项研究中， 在这里，我们的目标是开始验证脑压力被动性的能力， 我们的技术来识别即将发生的脑室内出血（GM-IVH） 通过4小时“侦察”美国研究发现。此外，我们还将努力确定 全身血压和二氧化碳水平，使压力被动。如果得到验证， 这种方法将对生物医学和临床研究的进步产生巨大的好处 最重要的是，这将导致最终发展理性的大脑导向， 血液动力学管理，防止早产儿的毁灭性脑损伤。 因此，这里提出的工作直接针对最大限度地增加这方面的机会。 使极其脆弱的人口能够发挥其健康和生产性生活的潜力 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.