VASOREACTIVITY OF CEREBRAL HEMODYNAMICS-NEONATES WITH CONGENITAL HEART DEFECTS

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目及 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者的研究机构。 在新生儿心脏手术的幸存者中观察到神经发育受损的结果， 先天性心脏病有先前的证据表明，术前脑 幸福感取决于观察结果。此外，众所周知， 包括心脏旁路、深度冷却和停搏，需要通过实时床旁优化 监测.一个很大程度上无法获得的关键参数是脑血流量（CBF）。我们有 最近开发的扩散相关光谱（DCS），用于非侵入性连续测量 相对CBF。在这项工作中，我们报告了我们的第一个结果，从临床应用到新生儿， 它与扩散光学光谱（DOS）相结合用于测量血氧， 脑氧代谢在这项两个队列研究中，患有严重先天性心脏病的新生儿 计划进行心脏手术的患者在术前进行测量，以评估大脑CO2反应性， 自动调节第一个队列（n=44）在高碳酸血症的延长期进行测量， 根据动脉自旋标记MRI测量结果验证MRI磁体和DCS测量结果， CBF显示两种方法之间具有良好的一致性。C 02反应性的损害不明显。 由于文献中报道的CO2反应性值的大范围和样品大小，观察到了这一点。 目前正在招募第二个队列（n=18）进行更广泛的监测，包括 术前准备期，并与术后结果进行统计学比较 结果测量。我们监测了这个新的脑血流和氧合变化， 使用床边光学技术在心脏手术后立即对队列进行12小时的观察。 我们 脑自动调节受损的时期，即脑血流 和平均动脉压高度相关。 此外，手术后一周，受试者 接受术后解剖MRI扫描，以确定缺氧缺血性损伤的程度（如果有的话） 白色物质损伤。 本研究的第3阶段旨在研究这些患者的绝对光学特性， 更准确地量化组织氧饱和度（StO 2）和脑代谢率的变化， 氧提取（CMRO 2）。 目前，我们根据公布的数据对这些婴儿的基线光学特性进行假设。 值，这是非常稀疏的，以近似StO 2和CMRO 2。 我们将设计和 实施新的光学探针来评估每个患者的这些特性，作为我们现有的 明确评估StO 2和CMRO 2的方案。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Impaired neurodevelopmental outcome has been observed for survivors of neonatal heart surgery for congenital heart defects. There is prior evidence indicating the importance of preoperative cerebral well-being on the observed outcome. Furthermore, it is well known that the surgical parameters which include cardiac by-pass, deep-cooling and arrest need to be optimized via real-time, bed-side monitoring. A crucial parameter that is largely inaccessible is the cerebral blood flow (CBF). We have recently developed diffuse correlation spectroscopy (DCS) for non-invasive, continuous measurement of relative CBF. In this work, we report our first results from its clinical application to neonates where it was combined with diffuse optical spectroscopy (DOS) for measurement of blood oxygenation and cerebral oxygen metabolism. In this two-cohort study, neonates with severe congenital heart defects scheduled for cardiac surgery were measured preoperatively to assess cerebral C02 reactivity and autoregulation. The first cohort (n=44) was measured during an extended period of hypercapnia in the MRI magnet and DCS measurement was validated against arterial spin-labeling MRI measure of CBF showing good agreement between two methods. An impairment of C02 reactivity was not observed due to large range of C02 reactivity values reported in the literature and the sample size. The second cohort is now being recruited (n=18) for a more extended monitoring including the preoperative preparation period and statistically comparing the findings with the post-operative outcome measures. We have monitored cerebral blood flow and oxygenation changes in this new cohort for 12 hours immediately following cardiac surgery using bedside optical techniques. We are investing periods of damaged cerebral autoregulation, i.e. periods of time in which cerebral blood flow and mean arterial pressure are highly correlated. Additionally, a week after surgery, the subjects undergo a post-surgical anatomical MRI scan to determine the extent, if any, of hypoxic-ischemic white matter injury. Phase 3 of this study aims to investigate absolute optical properties of these patients in order to more accurately quantify changes in tissue oxygen saturation (StO2), and cerebral metabolic rate of oxygen extraction (CMRO2). Currently, we make assumptions on baseline optical properties of these infants based on published values, which are very sparse, in order to approximate StO2 and CMRO2. We will design and implement a new optical probe to assess these properties on each patient as part of our existing protocol to definitively evaluate StO2 and CMRO2.