Department of Anaesthesiology and Intensive Care Medicine, Medical University of Graz, Graz, Austria.
Neurosurgery. 2010 Sep;67(3 Suppl Operative):ons102-7; discussion ons107. doi: 10.1227/01.NEU.0000383152.50183.81.
Patients undergoing carotid endarterectomy for extracranial internal carotid artery stenosis are at risk of cerebral ischemia/hypoperfusion. Criterion recommended by European and American committees to determine whether to place a shunt consisted of a decline in transcranial Doppler ultrasonography-measured middle cerebral artery blood flow velocity (MCBFV) to < 30% to 40% of intraoperative preclamp value.
To assess the discriminative power of the bispectral index (BIS)-Vista monitor for detecting a 40% decline in MCBFV with cross-clamping.
In 20 patients undergoing carotid endarterectomy under remifentanil/propofol anesthesia, BIS-Vista data, MCBFV, and pulsatility index from bilaterally mounted BIS-Vista and transcranial Doppler monitors were continuously recorded.
Coefficient of determination revealed good correlation (r = 0.763) between ipsilateral BIS-Vista and MCBFV after cross-clamping. BIS-Vista exhibited a high discriminative power of 0.850 (95% confidence interval, 0.455-0.966) area under the receiver-operating characteristic curve in detecting an ipsilateral 40% MCBFV decline. Two-way analysis of variance (location by time) suggests that BIS-Vista exhibited a global decline; ie, both BIS-Vistas declined when 1 carotid on either side was clamped because there was no significant interhemispheric difference (P = .112) in mean BIS-Vista values over time.
Although we demonstrated good correlation and high discriminative power of the BIS-Vista monitor in depicting a MCBFV decline that could serve as indicator of decline in cerebral activity, BIS-Vista cannot be considered a reliable indicator of cerebral ischemia/hypoperfusion that could replace transcranial Doppler monitoring to determine whether a shunt is to be placed.
接受颅外颈内动脉狭窄颈动脉内膜切除术的患者存在脑缺血/低灌注的风险。欧美委员会推荐的标准是通过经颅多普勒超声测量的大脑中动脉血流速度（MCBFV）下降来确定是否放置分流器，下降幅度为术中夹闭前值的 30%至 40%。
评估双频谱指数（BIS）-Vista 监测仪在检测夹闭时 MCBFV 下降 40%的能力。
在 20 例接受瑞芬太尼/丙泊酚麻醉下颈动脉内膜切除术的患者中，连续记录 BIS-Vista 数据、MCBFV 和双侧安装的 BIS-Vista 和经颅多普勒监测仪的搏动指数。
夹闭后，同侧 BIS-Vista 与 MCBFV 之间的决定系数显示出良好的相关性（r=0.763）。BIS-Vista 在检测同侧 MCBFV 下降 40%方面具有较高的区分能力，ROC 曲线下面积为 0.850（95%置信区间，0.455-0.966）。双向方差分析（位置与时间）表明 BIS-Vista 表现出全局下降；即当一侧的 1 条颈动脉被夹闭时，双侧 BIS-Vista 都下降，因为同侧之间的平均 BIS-Vista 值没有显著差异（P=0.112）。
尽管我们证明了 BIS-Vista 监测仪在描绘 MCBFV 下降方面具有良好的相关性和较高的区分能力，可以作为脑活动下降的指标，但 BIS-Vista 不能被视为可靠的脑缺血/低灌注指标，不能替代经颅多普勒监测来确定是否放置分流器。
