Validation in Baboon Model of Broadband NIR Monitoring for Neonate Gut Perfusion

描述（由申请人提供）：极早产儿的床边管理依赖于传统的监测方法，如动脉血压、心率、脉搏血氧仪、尿量和代谢性酸中毒的证据。然而，这些参数在检测组织灌注不良时可能会延迟或误导。通常情况下，即使组织灌注可能不足，由于代偿性血管收缩，动脉血压可能在正常范围内。尽管这些措施被广泛使用，但没有研究表明使用这些措施可以改善预后，并且单独依赖这些措施可能导致不适当的心血管干预。组织光谱学可以通过测量局部、静脉加权、血氧饱和度，更直接地测量组织的氧输送是否充足，并且对局部缺血很敏感。Spectros于2006年推出了第一款可见光光谱血氧仪T-Stat。T-Stat通过使用可见光而不是近红外（更常用于组织血氧测定），并结合宽带光谱（数百波长）来进一步提高测量精度，从而提高了性能。Spectros现在将这种方法扩展到红外宽带可见/红外血氧仪，从而可以可靠地测量许多物质。肠道功能受损是新生儿重症监护中发病率和死亡率的主要来源。肠道功能障碍表现为喂养不耐受、生长不良、吸收不良，严重时可出现坏死性小肠结肠炎（NEC）。虽然近红外氧饱和度仪已应用于新生儿的躯体（肾脏、肠道），但其无法补偿组织中不同水平的脂肪、水和粪便，严重限制了其作为躯体灌注监测的效用。因此，我们希望开发一种非侵入性躯体监测仪，使用光谱的可见/近红外部分，达到非侵入性躯体监测所需的穿透深度，但也结合了所需的宽带分析技术，以补偿可能存在的水、脂肪和粪便。这项研究的影响可能是真正重要的。本项目旨在研究组织灌注作为循环损伤早期识别的标志物，为有躯体器官损伤风险的患者提供早期识别。通过对这些患者的早期识别，我们预计灌注靶点可以更好地管理喂养、输血和使用肌力药物，从而显著改善这些患者的预后并降低医院费用。目标1 -减少制造用于监测肠道氧合的宽带可见/近红外组织血氧仪，在刚刚完成的NIH可行性研究中原型，并校正粪便，脂肪和水的值。目的2 -确定宽带血氧仪在极低出生体重早产儿狒狒模型中检测组织灌注和肠道血流诱导变化的有效性。目的3 -确定与T-Stat灌注监测仪一起使用的探针的安全性。

DESCRIPTION (provided by applicant): The bedside management of extremely pre-term neonates relies on the traditional methods of monitoring such as arterial blood pressure, heart rate, pulse oximetry, urine output and evidence of metabolic acidosis. However, these parameters may be delayed or misleading in the detection of poor tissue perfusion. Very frequently even though tissue perfusion may be inadequate, the arterial blood pressure may be in a normal range due to compensatory vasoconstriction. Despite their widespread use, no study has shown that use of these measures improves outcome, and reliance on these measures alone, may result in inappropriate cardiovascular intervention. Tissue spectroscopy can provide a more direct measure of the adequacy of oxygen delivery to tissue, by measuring local, venous-weighted, blood oxygen saturation, and is sensitive to local ischemia. Spectros introduced the first visible light spectroscopy oximeter, T-Stat, in 2006. The T-Stat achieves improved performance by using visible light as opposed to near-infrared (more commonly used in tissue oximetry), and by incorporating broadband spectroscopy (hundreds of wavelengths) to further improve accuracy of the measurement. Spectros is now extending this approach into the infrared with broadband visible/infrared oximetry, allowing for a number of substances to be reliably measured. Impaired intestinal function is a major source of morbidity and mortality in neonatal intensive care. Intestinal dysfunction is manifested by feeding intolerance, poor growth, malabsorbtion, and, in the severest cases, necrotizing enterocolitis (NEC). While NIRS oximetry devices have been applied somatically (renal, gut) in neonates, their inability to compensate for varying levels of fat, water and stool in the tissue has severely limited their utility as monitors of somatic perfusion. It is therefore desirable to develop a non-invasive somatic monitor using the visible/near-infrared portion of the spectrum that achieves the depth of penetration necessary for non-invasive somatic monitoring, but which also incorporates the broadband analysis techniques required to compensate for water, fat and stool that may be present. The impact of this study could be truly significant. This project is designed to study tissue perfusion as a marker for the early identification of circulatory compromise, providing early identification of patients at risk of somatic organ damage. Through the early identification of these patients, we anticipate perfusion targets can be developed to better manage feeding, transfusion, and use of inotropes to significantly improve outcome and reduce hospital costs for these patients. Aim 1 - To reduce to manufacturing a broadband Vis/NIR tissue oximeter for monitoring the oxygenation of the gut, prototyped in a just-completed NIH feasibility study, with values corrected for stool, fat, and water. Aim 2 - To determine the efficacy of the broadband oximeter to detect induced changes in tissue perfusion and intestinal blood flow in a premature baboon model for very low birth weight infants. Aim 3 - To determine the safety of probes used with the T-Stat Perfusion Monitor.