Neuroscience ICU, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan University, Milan, Italy.
J Neurosurg Anesthesiol. 2013 Jul;25(3):279-84. doi: 10.1097/ANA.0b013e3182913afd.
Asleep-awake craniotomy presents challenges for the anesthetist who has to provide adequate sedation and analgesia but also requires an awake and cooperative patient for neurological testing. In this setting, we hypothesized that Bispectral Index (BIS) monitoring might be helpful in shortening the patient's awakening and in predicting recovery of consciousness in order to initiate reliable intraoperative brain mapping.
An observational prospective study was performed on 27 consecutive asleep-awake craniotomies, in which BIS was monitored and BIS data collected offline. Nine critical intraoperative time points were defined and analyzed [preinduction, start of surgery, termination of hypnotic drug, eye opening, obeying simple commands, laryngeal mask airway (LMA) removal, initiation of brain mapping, initiation of closure, and end of surgery].
A shorter time to LMA removal was associated with a higher BIS at the termination of the hypnotic drug (P=0.016, Mann-Whitney U test). From the initiation of surgery to the time of LMA removal, BIS was significantly lower than the preinduction values, whereas at the initiation of brain mapping, BIS returned to the preinduction values (Friedman test P<0.0001, Dunns multiple comparisons test). Compared with LMA removal, BIS values >85 predicted the initiation of brain mapping with a sensitivity of 44% (95% confidence interval, 25.5%-64.7%) and a specificity of 74% (95% confidence interval, 53.7%-89%).
During asleep-awake craniotomies, higher BIS values at the end of the asleep phase are associated with shorter time to LMA removal, suggesting that BIS monitoring may be beneficial in shortening recovery from anesthesia. During the awake phase, the return of BIS to the preinduction values appeared to indicate full recovery of consciousness, thereby allowing a reliable language testing.
在唤醒开颅术中，麻醉师需要提供足够的镇静和镇痛，但也需要患者保持清醒和合作，以便进行神经学测试。在这种情况下，我们假设双频谱指数（BIS）监测可能有助于缩短患者的苏醒时间，并预测意识恢复，以便开始可靠的术中脑映射。
对 27 例连续进行的唤醒开颅术进行了观察性前瞻性研究，在此期间监测 BIS 并离线收集 BIS 数据。定义并分析了 9 个关键的术中时间点[诱导前、手术开始、催眠药物终止、睁眼、听从简单指令、喉罩气道（LMA）移除、开始脑映射、开始闭合和手术结束]。
LMA 移除时间较短与催眠药物终止时 BIS 较高相关（P=0.016，Mann-Whitney U 检验）。从手术开始到 LMA 移除时，BIS 明显低于诱导前值，而在开始脑映射时，BIS 恢复到诱导前值（Friedman 检验 P<0.0001，Dunns 多重比较检验）。与 LMA 移除相比，BIS 值>85 预测开始脑映射的灵敏度为 44%（95%置信区间，25.5%-64.7%），特异性为 74%（95%置信区间，53.7%-89%）。
在唤醒开颅术中，入睡阶段结束时 BIS 值较高与 LMA 移除时间较短相关，表明 BIS 监测可能有助于缩短麻醉恢复。在清醒阶段，BIS 恢复到诱导前值似乎表明意识完全恢复，从而允许进行可靠的语言测试。
