Continuous Monitoring for Cerebral Pressure-Passivity in Premature Infants

描述（由申请人提供）：早产儿脑损伤是一个严重的问题，主要由未成熟脑中血管调节紊乱引起的脑血管机制介导。压力被动性是脑血管调节紊乱的主要表现，在早产儿缺氧缺血性（HI）和出血性脑损伤中起关键作用。当全身血压（BP）不稳定和脑压力自动调节受损时，脑压力被动性发展。我们已经证明，低血压，以及波动的血压和脑压被动是常见的患病早产儿。缺乏一个综合的床边技术，连续监测这些信号之间的动态关系，以确定脑压力被动阻碍了制定合理的策略，BP管理，旨在防止早产儿脑损伤。我们已经开发了这样一个系统，测量连续脑近红外光谱（NIRS）和BP的变化，以确定在床边的患病婴儿的脑压力被动期。我们测量系统BP和脑NIRS血红蛋白差异（HbD）信号变化之间的相关性（使用传递函数分析）;然后我们推导出压力被动指数（PPI），以量化压力被动随时间的变化。在这里提出的研究中，我们的目标是开始验证我们的技术测量的脑压力被动性的能力，以识别即将发生的脑室内出血（GM-IVH）检测的4小时“侦察”US研究。此外，我们将寻求定义系统BP和CO2水平的特点，易患压力被动。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，它将导致最终发展合理的以大脑为导向的血流动力学管理，以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为这一极端弱势群体提供机会，使他们能够充分发挥潜力，过上健康和富有成效的生活，不受疾病或残疾的阻碍。早产儿脑血管损伤会导致毁灭性的长期神经发育疾病，是一个巨大的公共卫生问题。对血流动力学损伤的不完全理解以及在损伤变得不可逆之前无法识别这些损伤阻碍了这种损伤的预防。我们已经开发出一种技术，旨在填补这两个空白，现在寻求支持其在患病早产儿中的验证。

DESCRIPTION (provided by applicant): 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. Cerebrovascular injury in premature infants causes devastating longterm neurdevelopmental morbidity and is a public health issue of enormous magnitude. Prevention of this injury has been impeded by an incomplete understanding of the hemodynamic insults involved and the inability to identify these insults before injury becomes irreversible. We have developed a technique that aims to fill both these voids and now seek support for its validation in sick premature infants.