Continuous time-domain analysis of cerebrovascular autoregulation using near-infrared spectroscopy
Continuous time-domain analysis of cerebrovascular autoregulation using near-infrared spectroscopy
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DOI：
10.1161/strokeaha.107.485706
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发表时间：
2007-10-01
期刊：
影响因子：
8.3
通讯作者：
Shaffner, Donald H.
中科院分区：
文献类型：
--
作者：
Brady, Ken M.;Lee, Jennifer K.;Shaffner, Donald H.
背景与目的-时间域自动调节评估是一种很有前途的监测方法，可用于主动优化危重患者的脑灌注压（CPP）。通过一种新的时域方法，利用近红外光谱测量婴儿动物模型中的组织氧血红蛋白饱和度，检测CPP自发波动导致的自身调节血管反应性丧失的能力。方法：通过下腔静脉充气球囊导管使仔猪在4 ~ 5小时内逐渐降压，并使用激光多普勒血流仪测定自动调节的断点。测定脑氧饱和度指数（COx）为300秒内CPP与INVOS脑氧饱和度波形之间的移动线性相关系数。在相同参数（LDx）下，还确定了激光多普勒导出的自发自调节时域分析。结果-当CPP低于稳态自动调节断点时，脑氧饱和度值与动态CPP波动之间的相关系数增加，表明存在压力被动关系。当COx高于0.36阈值时，该COx检测由低血压引起的自身调节丧失的灵敏度为92%(73%至99%)，特异性为63%（48%至76%）。COx的接受者-操作者特征曲线下面积为0.89。根据得到的CPP值进行排序和平均，COx与LDx相关（r = 0.67）。结论：COx对低血压引起的自身调节功能丧失很敏感，是一种很有前途的监测工具，可用于确定急性脑损伤患者的最佳CPP。
Background and Purpose - Assessment of autoregulation in the time domain is a promising monitoring method for actively optimizating cerebral perfusion pressure (CPP) in critically ill patients. The ability to detect loss of autoregulatory vasoreactivity to spontaneous fluctuations in CPP was tested with a new time-domain method that used near-infrared spectroscopic measurements of tissue oxyhemoglobin saturation in an infant animal model.Methods - Piglets were made progressively hypotensive over 4 to 5 hours by inflation of a balloon catheter in the inferior vena cava, and the breakpoint of autoregulation was determined using laser-Doppler flowmetry. The cerebral oximetry index (COx) was determined as a moving linear correlation coefficient between CPP and INVOS cerebral oximeter waveforms during 300-second periods. A laser-Doppler derived time-domain analysis of spontaneous autoregulation with the same parameters (LDx) was also determined.Results - An increase in the correlation coefficient between cerebral oximetry values and dynamic CPP fluctuations, indicative of a pressure-passive relationship, occurred when CPP was below the steady state autoregulatory breakpoint. This COx had 92% sensitivity (73% to 99%) and 63% specificity (48% to 76%) for detecting loss of autoregulation attributable to hypotension when COx was above a threshold of 0.36. The area under the receiver-operator characteristics curve for the COx was 0.89. COx correlated with LDx when values were sorted and averaged according to the CPP at which they were obtained (r = 0.67).Conclusions - The COx is sensitive for loss of autoregulation attributable to hypotension and is a promising monitoring tool for determining optimal CPP for patients with acute brain injury.