Closed-loop control of anesthesia using bispectral index - Performance assessment in patients undergoing major orthopedic surgey under combined general and regional anesthesia
Closed-loop control of anesthesia using bispectral index - Performance assessment in patients undergoing major orthopedic surgey under combined general and regional anesthesia
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DOI：
10.1097/00000542-200201000-00017
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发表时间：
2002-01-01
期刊：
影响因子：
8.8
通讯作者：
Kenny, GN
中科院分区：
文献类型：
--
作者：
Absalom, AR;Sutcliffe, N;Kenny, GN
背景：脑电双频指数（BIS）是一种源自脑电图的麻醉深度测量指标。以BIS作为控制变量、采用比例 - 积分 - 微分控制算法，并以丙泊酚靶控输注系统作为控制执行器，构建了一个闭环麻醉系统。对10例成年患者进行了闭环性能评估。
方法：纳入10例计划择期行髋关节或膝关节手术的成年患者。插入硬膜外导管，在全身麻醉诱导前，使用0.5%布比卡因对T8进行麻醉，全身麻醉采用手动控制下的丙泊酚靶控输注系统诱导。手术开始后，当临床麻醉充分时，以BIS作为控制变量开始自动控制麻醉。通过临床评估以及计算中位执行误差、中位绝对执行误差和控制变量的平均偏移来评估闭环控制期间麻醉的充分性。
结果：中位执行误差和中位绝对执行误差分别为2.2%和8.0%。BIS与设定点的平均偏移为0.9。闭环控制期间心血管参数稳定。除1例外，所有患者的手术条件均良好，该患者在稳定麻醉45分钟后开始移动。无患者报告术中知晓或回忆起术中事件。3例患者测量的BIS在设定点周围波动。
结论：该系统能够在10例患者中的9例提供临床充分的麻醉。需要进一步研究以确定通过改变增益因子或使用效应部位靶向的丙泊酚靶控输注系统是否可以提高控制性能。
Background: The Bispectral Index (BIS) is an electroencephalogram-derived measure of anesthetic depth. A closed-loop anesthesia system was built using BIS as the control variable, a proportional-integral-differential control algorithm, and a propofol target-controlled infusion system as (lie control actuator. Closed-loop performance was assessed in 10 adult patients.Methods: Ten adult patients scheduled to undergo elective hip or knee surgery were enrolled. An epidural cannula was inserted, and 0.5% bupivacaine was used to provide anesthesia to T8 before general anesthesia was Induced using (lie propofol target-controlled infusion system under manual control. After the start of surgery, when anesthesia was clinically adequate, automatic control of anesthesia was commenced using the BIS as the control variable. Adequacy of anesthesia during closed-loop control was assessed clinically and by calculating the median performance error, the median absolute performance error, and the mean offset of the control variable.Results: The median performance error and the median absolute performance error were 2.2 and 8.0%, respectively. Mean offset of the BIS from the set point was 0.9. Cardiovascular parameters were stable during closed-loop control. operating conditions were adequate in all patients but one, who began moving after 45 min of stable anesthesia. No patients reported awareness or recall of Intraoperative events. hi three patients, there was oscillation of the measured BIS around the set point.Conclusions: The system was able to provide clinically adequate anesthesia in 9 of 10 patients. Further studies are required to determine whether control performance can be improved by alterations to the gain factors or by using an effect site-targeted, target-controlled infusion propofol system.