Hori Daijiro, Hogue Charles W, Shah Ashish, Brown Charles, Neufeld Karin J, Conte John V, Price Joel, Sciortino Christopher, Max Laura, Laflam Andrew, Adachi Hideo, Cameron Duke E, Mandal Kaushik
From the *Division of Cardiac Surgery, Department of Surgery, †Department of Anesthesiology and Critical Care Medicine, and ‡Department of Psychiatry & Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland; and §Division of Cardiovascular Surgery, Saitama Medical Center, Jichi Medical University, Saitama, Japan.
Anesth Analg. 2015 Nov;121(5):1187-93. doi: 10.1213/ANE.0000000000000930.
Individualizing mean arterial blood pressure (MAP) based on cerebral blood flow (CBF) autoregulation monitoring during cardiopulmonary bypass (CPB) holds promise as a strategy to optimize organ perfusion. The purpose of this study was to evaluate the accuracy of cerebral autoregulation monitoring using microcirculatory flow measured with innovative ultrasound-tagged near-infrared spectroscopy (UT-NIRS) noninvasive technology compared with transcranial Doppler (TCD).
Sixty-four patients undergoing CPB were monitored with TCD and UT-NIRS (CerOx™). The mean velocity index (Mx) was calculated as a moving, linear correlation coefficient between slow waves of TCD-measured CBF velocity and MAP. The cerebral flow velocity index (CFVx) was calculated as a similar coefficient between slow waves of cerebral flow index measured using UT-NIRS and MAP. When MAP is outside the autoregulation range, Mx is progressively more positive. Optimal blood pressure was defined as the MAP with the lowest Mx and CFVx. The right- and left-sided optimal MAP values were averaged to define the individual optimal MAP and were the variables used for analysis.
The Mx for the left side was 0.31 ± 0.17 and for the right side was 0.32 ± 0.17. The mean CFVx for the left side was 0.33 ± 0.19 and for the right side was 0.35 ± 0.19. Time-averaged Mx and CFVx during CPB had a statistically significant "among-subject" correlation (r = 0.39; 95% confidence interval [CI], 0.22-0.53; P < 0.001) but had only a modest agreement within subjects (bias 0.03 ± 0.20; 95% prediction interval for the difference between Mx and CFVx, -0.37 to 0.42). The MAP with the lowest Mx and CFVx ("optimal blood pressure") was correlated (r = 0.71; 95% CI, 0.56-0.81; P < 0.0001) and was in modest within-subject agreement (bias -2.85 ± 8.54; 95% limits of agreement for MAP predicted by Mx and CFVx, -19.60 to 13.89). Coherence between ipsilateral middle CBF velocity and cerebral flow index values averaged 0.61 ± 0.07 (95% CI, 0.59-0.63).
There was a statistically significant correlation and agreement between CBF autoregulation monitored by CerOx compared with TCD-based Mx.
在体外循环（CPB）期间，基于脑血流（CBF）自动调节监测来个体化平均动脉血压（MAP），有望成为优化器官灌注的一种策略。本研究的目的是评估使用创新的超声标记近红外光谱（UT-NIRS）无创技术测量的微循环血流来监测脑自动调节与经颅多普勒（TCD）相比的准确性。
对64例接受CPB的患者进行TCD和UT-NIRS（CerOx™）监测。平均速度指数（Mx）计算为TCD测量的CBF速度慢波与MAP之间的移动线性相关系数。脑血流速度指数（CFVx）计算为使用UT-NIRS测量的脑血流指数慢波与MAP之间的类似系数。当MAP超出自动调节范围时，Mx会逐渐变得更正。最佳血压定义为具有最低Mx和CFVx的MAP。将左右两侧的最佳MAP值平均以定义个体最佳MAP，并将其作为分析变量。
左侧的Mx为0.31±0.17，右侧的Mx为0.32±0.17。左侧的平均CFVx为0.33±0.19，右侧的平均CFVx为0.35±0.19。CPB期间的时间平均Mx和CFVx具有统计学上显著的“受试者间”相关性（r = 0.39；95%置信区间[CI]，0.22 - 0.53；P < 0.001），但在受试者内仅有适度的一致性（偏差0.03±0.20；Mx和CFVx差异的95%预测区间，-0.37至0.42）。具有最低Mx和CFVx的MAP（“最佳血压”）具有相关性（r = 0.71；95%CI，0.56 - 0.81；P < 0.0001），并且在受试者内有适度的一致性（偏差-2.85±8.54；由Mx和CFVx预测的MAP的95%一致性界限，-19.60至13.89）。同侧大脑中CBF速度与脑血流指数值之间的相干性平均为0.61±0.07（95%CI，0.59 - 0.63）。
与基于TCD的Mx相比，CerOx监测的CBF自动调节之间存在统计学上显著的相关性和一致性。
