Tissue oxygen index - Thresholds for cerebral ischemia using near-infrared spectroscopy
Tissue oxygen index - Thresholds for cerebral ischemia using near-infrared spectroscopy
复制标题
DOI：
10.1161/01.str.0000244807.99073.ae
复制
发表时间：
2006-11-01
期刊：
影响因子：
8.3
通讯作者：
Kirkpatrick, Peter J.
中科院分区：
文献类型：
--
作者：
Al-Rawi, Pippa G.;Kirkpatrick, Peter J.
背景和目的-到目前为止，近红外光谱在成人大脑中的临床应用还很有限。NIRO 300（Hamamatsu Photonics）使用空间分辨光谱法提供组织氧指数（TOI）的连续测量。虽然TOI反映脑氧合的高度敏感性和特异性，成为一个有用的临床工具，脑缺血的阈值需要定义。这项研究试图确定一个可量化的TOI阈值缺血在成人brain. Methods一百六十七例接受颈动脉内膜切除术进行了研究。NIRO 300被整合到一个已建立的多模式监测系统中，能够在高度受控的条件下观察脑血流动力学变化。将颈内动脉夹闭时TOI的变化（% Δ TOI）与颅内血流（大脑中动脉血流速度）和脑功能监测进行比较，以确定和量化脑缺血的时间。31例患者在颈内动脉夹闭时显示脑缺血，定义为脑功能监测持续下降。确定了-13的% Δ TOI的阈值，高于该阈值时，没有患者在夹闭时显示出任何缺血证据。这个阈值提供了100%的灵敏度和93.2%的特异性为患者满足预设的脑ischemia. Conclusions标准，这些数据表明，有可能识别TOI量化阈值脑缺血在成人大脑，从而提高近红外光谱的临床应用。我们的观察已经定义了TOI下降（13%），可以作为严重脑缺血的阈值，具有高灵敏度和特异性。
Background and Purpose-To date, the clinical application of near infrared spectroscopy in the adult brain has been limited. The NIRO 300 (Hamamatsu Photonics) provides a continuous measurement of tissue oxygen index (TOI) using spatially resolved spectroscopy. Although TOI reflects cerebral oxygenation to a high degree of sensitivity and specificity, to become a useful clinical tool, thresholds for cerebral ischemia need to be defined. This study has attempted to identify a quantifiable TOI threshold for ischemia in the adult brain.Methods-One hundred sixty-seven patients undergoing carotid endarterectomy were studied. The NIRO 300 was incorporated into an established multimodal monitoring system enabling observations of cerebral hemodynamic changes under highly controlled conditions. Changes in TOI (%Delta TOI) on clamping the internal carotid artery were compared with intracranial blood flow (middle cerebral artery flow velocity) and cerebral function monitoring to identify and quantify periods of cerebral ischemia.Results-Significant correlation was seen between changes in middle cerebral artery flow velocity and Delta TOI on clamping (r=0.74, P=0.0001). Thirty-one patients showed cerebral ischemia on internal carotid artery clamping as defined by a sustained fall in cerebral function monitoring. A threshold for %Delta TOI of -13 was identified, above which no patients showed any evidence of ischemia on clamping. This threshold provided 100% sensitivity and 93.2% specificity for patients satisfying the preset criteria for cerebral ischemia.Conclusions-These data demonstrate the potential to identify TOI-quantified thresholds for cerebral ischemia in the adult brain and thus improve the clinical use of near infrared spectroscopy. Our observations have defined a drop in TOI (13%) that can be adopted as a threshold for severe cerebral ischemia with high sensitivity and specificity.