硬膜外复合丙泊酚静脉麻醉对老年人脑电双频谱指数和心率变异的影响

目的　探讨老年人硬膜外复合丙泊酚静脉麻醉中脑电双频谱指数 (BIS)和心率变异性(HRV)的改变。方法　择期腹部手术病人 4 0例 ,按年龄分成年轻组和老年组。诱导前T8～ 1 1 穿刺置管 ,咪唑安定 0 1mg/kg、丙泊酚 1mg/kg、维库溴铵 0 1mg/kg、芬太尼 3μg/kg诱导后插管 ,丙泊酚4mg·kg 1 ·h 1 恒速泵入维持麻醉 ,术中每 4 5～ 6 0min硬膜外追加局麻药 3～ 5ml,静注芬太尼 1～2 μg/kg、维库溴铵 0 0 5mg/kg。记录入室后、诱导后、插管后、术中及清醒睁眼时的BIS、低频与高频比值 (LF/HF) ;记录手术时间、术中用药情况、术中发生低血压和心动过缓次数。结果　两组平均年龄分别为 (31 4 4± 6 6 9)岁和 (71 0 0± 5 1 5 )岁 ,P <0 0 1。手术时间分别为 (1 96 1 1± 36 94 )和(2 0 8 34± 2 4 0 0 )min ,P >0 0 5。用药情况及各时点BIS值未见显著性差异 ;组间诱导和插管后的LF/HF有显著性差异 (P <0 0 1 ) ;两组低血压发生率分别是 2 0 %和 5 5 % ,P <0 0 5 ;心动过缓发生率分别是 1 0 %和 2 0 % ,P >0 0 5。结论　BIS可较好地反映硬膜外复合丙泊酚静脉全麻的镇静深度 ,且不受年龄影响 ,心率变异的LF/HF可较好地反映老年人围麻醉期间自主神经功能的均衡性 ,为老年人围术期的管理提供有益的指     

心率变异性近似熵分析法与脑电双频谱指数间的相关性

目的:观察全身麻醉时心率变异性分析中近似熵分析法与脑电双频谱指数(BIS)在监测麻醉深度时的相关性。方法:对40例全身麻醉病人测定麻醉前(T1)、诱导插管(T2)、术中(T3)、苏醒(T4)4个时间点各5min的心率(HR)、平均动脉压(MAP)、脑电双频谱指数(BIS)和近似熵(ApEn)变化。结果:HR在T2、T3和T4均较T1值升高(P0.01～0.05)。MAP在T2时较T1值降低(P0.05),T3、T4较T1值升高(P0.05),而T4比T3明显升高(P0.01)。BIS值在麻醉后各时点均较T1值下降明显(P0.01),其中T4也较T1下降(P0.05),T3与T2时相比明显降低(P0.01),而T4较T3明显升高(P0.01)。近似熵值的T1值均大于其他各时点(P0.01～0.05),其T4较T3时点升高(P0.01),T3较T2时点降低(P0.05)。结论:作为心率变异性的非线性分析方法指标的近似熵分析法,能描述围术期心脏自主神经功能状态的变化,但其与BIS并无相关性。     

氯胺酮和依托咪酯的BIS50及其对脑电双频指数的影响

目的 分别测定氯胺酮和依托咪酯诱导时半数患者入睡时的脑电双频指数(BIS)即BIS50和半数有效量(ED50)，比较他们对BIS的影响。方法 选择40例无服用精神药物和镇静催眠药、无术前用药的择期手术患者(ASAⅠ～Ⅱ级)，随机分为氯胺酮组(K组，n=20)和依托咪酯组(E组，n=20)，以半数效量序贯法分别进行氯胺酮和依托咪酯诱导的睡眠观察，以对语言指令不应和睫毛反射消失为入睡指标，同时记录BIS的变化。对取得的数据以直线回归的方法和加权均数法分别求得氯胺酮、依托咪酯的BIS50和ED50。结果 氯胺酮和依托咪酯诱导后，BIS明显下降(P=0.000983)，但两者各自BIS下降幅度在入睡与未睡患者之间没有明显差异(P=0.920501和0.956263)。氯胺酮的BIS50和ED50分别是78．81(95％可信区间67．27～97．10)和0.757mg／kg(95％可信区间0.535～1．071mg／kg)，依托咪酯的BIS50和ED50分别是60．00(95％可信区间49．74～76．95)和0.089mg，／kg(95％可信区间0.073～0.107mg／kg)。结论 氯胺酮和依托咪酯皆显著降低BIS，但仅凭BIS难以准确预计是否进入睡眠状态。     

Titration of isoflurane using BIS index improves early recovery of elderly patients undergoing orthopedic surgeries

PURPOSE: This study was designed to investigate the effect of bispectral index (BIS) monitoring on the recovery profiles, level of postoperative cognitive dysfunction, and anesthetic drug requirements of elderly patients undergoing elective orthopedic surgery with general anesthesia. METHODS: Sixty-eight patients over the age of 60 were randomized into one of two groups. In the standard practice (SP) group, the anesthesiologists were blinded to the BIS value, and isoflurane was titrated according to standard clinical practice. In the BIS group, isoflurane was titrated to maintain a BIS value between 50-60. RESULTS: The total isoflurane usage was 30% lower in the BIS group compared to the SP group (5.6 +/- 3 vs 7.7 +/- 3 mL, P <0.05). The time to orientation was faster in the BIS group compared to the SP group (9.5 +/- 3 vs 13.1 +/- 4 min, P <0.001). There were no differences in the postoperative psychometric tests between the two groups. CONCLUSIONS: There was no difference in the level of postoperative cognitive dysfunction between the two groups. However, titration of isoflurane using the BIS index decreased utilization of isoflurane and contributed to faster emergence of elderly patients undergoing elective knee or hip replacement surgery.     

脑电双频指数指导吸入异氟烷对腹部手术老年病人麻醉恢复的影响

目的研究脑电双频指数(BIS)指导吸入异氟烷对腹部手术老年病人麻醉恢复的影响。方法65岁以上行腹部手术病人40例,ASAⅡ或Ⅲ级,随机分为对照组和BIS组,每组20例。对照组由同一麻醉科医生根据经验调节术中异氟烷的吸入浓度;BIS组术中维持BIS在50-60,手术结束前20min,BIS维持在60-70。记录诱导前、麻醉期间和拔管时的BIS、异氟烷挥发罐设定浓度和呼气末浓度;清醒时间、拔管时间和从手术结束至Aldrete麻醉恢复评分≥9的时间;简易智能状态检查(MMSE)评分。结果与对照组相比,BIS组术中异氟烷用量减少34%,麻醉、手术期间的BIS升高、呼气末异氟烷浓度降低,手术结束时呼气末异氟烷浓度降低,清醒时间、拔管时间和从手术结束至Aldrete麻醉恢复评分≥9的时间缩短;与麻醉前比较,BIS组术后1 h MMSE评分降低,对照组在术后1、2 h MMSE评分降低(P<0.05或0.01)。结论BIS指导吸入异氟烷能加快腹部手术老年病人麻醉恢复,并可减少术中异氟烷用量。     

Pediatric evaluation of the bispectral index (BIS) monitor and correlation of BIS with end-tidal sevoflurane concentration in infants and children

The bispectral index (BIS) has been developed in adults and correlates well with clinical hypnotic effects of anesthetics. We investigated whether BIS reflects clinical markers of hypnosis and demonstrates agent dose-responsiveness in infants and children. In an observational arm of this study, BIS values in children undergoing general anesthesia were observed and compared with similar data collected previously in a study of adults. In a second arm of the study, a range of steady-state end-tidal concentrations of sevoflurane was administered and corresponding BIS documented. Data were examined for differences between infants (0-2 yr) and children (2-12 yr). No difference was seen in BIS values in children before induction, during maintenance, and on emergence compared with adult values. There was no difference in BIS between infants and children at similar clinical levels of anesthesia. In children and infants, BIS was inversely proportional to the end-tidal concentration of sevoflurane. The sevoflurane concentration for a BIS = 50 (95% confidence interval) was significantly different: 1. 55% (1.40-1.70) for infants versus 1.25% (1.12-1.37) for children. Although validation with specific behavioral end points was not possible, BIS correlated with clinical indicators of anesthesia in children as it did in adults: as depth of anesthesia increased, BIS diminished. BIS correlated with sevoflurane concentration in infants and children. The concentration-response difference between infants and children was consistent with data showing that minimum alveolar concentration is higher in children less than 1 yr of age. IMPLICATIONS: The use of bispectral index (BIS) during general anesthesia improves the titration of anesthetics in adults. The data from this study suggest that the same equipment and method of electroencephalogram analysis may be applied to infants and children.     

Perioperative cerebral ischaemia in cardiac surgery and BIS

A 46-year-old woman was monitored by bispectral index monitoring (BIS) during redo aortic and mitral valve replacement. On release of the aortic cross clamp there was a sudden, severe, unexplained, and sustained fall in the BIS value. Postoperatively, a CT scan was consistent with multiple ischaemic lesions. The lesions were presumed to be due to air embolism. This case suggests that a sudden unexplained and persistent fall in BIS may indicate cerebral ischaemia.     

术中保温对老年患者全麻BIS恢复时间及苏醒期丙泊酚效应室浓度的影响

目的观察术中保温对老年患者全麻BIS恢复时间及苏醒期丙泊酚效应室浓度(Ce)的影响。方法选择60岁以上全麻下行开腹胃肠外科手术患者44例,随机分为保温组和对照组,每组22例。术中保温组采用输入液体、腹腔冲洗液体加温以及暖风毯覆盖等保温措施;对照组采用室温液体输入与铺巾覆盖。记录麻醉开始时(T0)、麻醉后30 min(T1)、60 min(T2)、90 min(T3)、120min(T4)、150min(T5)、术毕(T6)的食管温度和MAP。记录停药到BIS≥80的恢复时间、BIS≥80时丙泊酚Ce。结果T2~T6时对照组食管温度明显低于保温组(P0.05)。不同时点两组MAP差异无统计学意义。保温组患者停药到BIS≥80的恢复时间明显短于对照组,Ce明显高于对照组(P0.05)。结论低体温会延长老年患者BIS恢复时间,影响丙泊酚Ce的降低,术中保温有利于防止此类现象发生。