Neuroprotective effect of bispectral index-guided fast-track anesthesia using sevoflurane combined with dexmedetomidine for intracranial aneurysm embolization

Dexmedetomidine has sedative, anxiolytic, analgesic, anti-sympathetic, and anti-shivering effects. Dexmedetomidine might be effective in combination with sevoflurane for anesthesia, but prospective randomized controlled clinical trials with which to verify this hypothesis are lacking. In total, 120 patients who underwent embolization of an intracranial aneurysm were recruited from Anhui Provincial Hospital and Renmin Hospital of Wuhan University of China and randomly allocated to two groups. After intraoperative administration of 2% to 3% sevoflurane inhalation, one group of patients received pump-controlled intravenous injection of 1.0 ~tg/kg dexmedetomidine for 15 minutes followed by maintenance with 0.3 ~tg/kg/h until the end of surgery; the other group of patients only underwent pump-controlled infusion of saline. Bispectral index monitoring revealed that dexmedetomidine-assisted anesthesia can shorten the recovery time of spon- taneous breathing, time to eye opening, and time to laryngeal mask removal. Before anesthetic induction and immediately after laryngeal mask airway removal, the glucose and lactate levels were low, the S100~ and neuron-specific enolase levels were low, the perioperative blood pressure and heart rate were stable, and postoperative delirium was minimal. These findings indicate that dexmedetomidine can effectively assist sevoflurane for anesthesia during surgical embolization of intracranial aneurysms, shorten the time to consciousness and extubation, reduce the stress response and energy metabolism, stabilize hemodynamic parameters, and reduce adverse reactions, thereby reducing the damage to the central nervous system. This trial was registered at the Chinese Clinical Trial Registry （http：//www.chictr.org. cn/） （registration number： ChiCTR-IPR- 16008113）.

Bispectral index in predicting the prognosis of patients with coma in intensive care unit

BACKGROUND: The bispectral(BIS) index is a processed electroencephalogram(EEG) parameter with extensive validation and demonstrated clinical utility. The study aimed to investigate the correlation between the BIS index and the prognosis of patients with coma in the ICU.METHODS: A total of 208 patients with coma in the ICU were enrolled in this study. According to the BIS value, the patients were divided into four groups: group I, BIS value 0 to 20; group II, BIS value 21 to 40; group III, BIS value 41 to 60; and group IV, BIS value greater than 60. The difference in BIS values with the differences in prognosis of patients with coma was compared between the four groups, and the prognosis of patients with coma was stratified into consciousness, coma, vegetative state, and brain death. Subsequently, the best cut-off score of BIS values calculated for determining the correlation between BIS value and mental state was proposed.RESULTS: There are no significant differences in the age and APACHE II scores between the four groups(P>0.05). An inverse correlation was observed between BIS value and mental state(r= –0.749, P=0.00). According to the ROC curve, as BIS value was greater than 42.5, there were higher sensitivity and specificity in conscious-coma patients.CONCLUSION: BIS value is correlated with the prognosis of patients with coma in ICU, and BIS value can be a useful marker for estimating the prognosis of comatose patients.

Bispectral index monitoring as an adjunct to nurse-administered combined sedation during endoscopic retrograde cholangiopancreatography

AIM:To determine whether bispectral index (BIS) monitoring is useful for propofol administration for deep sedation during endoscopic retrograde cholangiopancreatography (ERCP). METHODS:Fifty-nine consecutive patients with a variety of reasons for ERCP who underwent the procedure at least twice between 1 July 2010 and 30 November 2010. This was a randomized cross-over study, in which each patient underwent ERCP twice, once with BIS monitoring and once with control monitoring. Whether BIS monitoring was done during the first or second ERCP procedure was random. Patients were intermittently administered a mixed regimen including midazolam, pethidine, and propofol by trained nurses. The nurse used a routine practice to monitor sedation using the Modified Observer's Assessment of Alertness/Sedation (MOAA/S) scale or the BIS monitoring. The total amount of midazolam and propofol used and serious side effects were compared between the BIS and control groups. RESULTS:The mean total propofol dose administered was 53.1 ± 32.2 mg in the BIS group and 54.9 ± 30.8 mg in the control group (P = 0.673). The individual propofol dose received per minute during the ERCP procedure was 2.90 ± 1.83 mg/min in the BIS group and 3.44 ± 2.04 mg in the control group (P = 0.103). The median value of the MOAA/S score during the maintenance phase of sedation was comparable for the two groups. The mean BIS values throughout the procedure (from insertion to removal of the endoscope) were 76.5 ± 8.7 for all 59 patients in using the BIS monitor. No significant differences in the frequency of < 80% oxygen saturation, hypotension (< 80 mmHg), or bradycardia (< 50 beats/min) were observed between the two study groups. Four cases of poor cooperation occurred, in which the procedure should be stopped to add the propofol dose. After adding the propofol, the procedure could be conducted successfully (one case in the BIS group, three cases in the control group). The endoscopist rated patient sedation as excellent for all patients in both groups. All patients in both groups rated their level of satisfaction as high (no discomfort). During the post-procedural follow-up in the recovery area, no cases of clinically significant hypoxic episodes were recorded in either group. No other postoperative side effects related to sedation were observed in either group. CONCLUSION:BIS monitoring trend to slighlty reduce the mean propofol dose. Nurse-administered propofol sedation under the supervision of a gastroenterologist may be considered an alternative under anesthesiologist.

Comparison of 1.5% lidocaine and 0.5% ropivacaine epidural anesthesia combined with propofol general anesthesia guided by bispectral index

Objective： To compare the effects of epidural anesthesia with 1.5% lidocaine and 0.5% ropivacaine on propofol requirements, the time to loss of consciousness （LOC）, effect-site propofol concentrations, and the hemodynamic variables during induction of general anesthesia guided by bispectral index （BIS） were studied. Methods： Forty-five patients were divided into three groups to receive epidurally administered saline （Group S）, 1.5% （w/w） lidocaine （Group L）, or 0,5% （w/w） ropivacaine （Group R） Propofol infusion was started to produce blood concentration of 4 lag/ml. Once the BIS value reached 40-50, endotracheal intubation was facilitated by 0.1 mg/kg vecuronium. Measurements included the time to LOC, effect-site propofol concentrations, total propofol dose, mean arterial blood pressure （MABP）, and heart rate （HR） at different study time points. Results： During induction of anesthesia, both Groups L and R were similar for the time to LOC, effect-site propofol concentrations, total propofol dose, MABP, HR, and BIS. The total doses of propofol administered until 1 min post-intubation were significantly less in patients of Groups R and L compared with Group S. MABP and HR were significantly lower following propofol induction compared with baseline values in the three groups, or MABP was significantly increased following intubation as compared with that prior to intubation in Group S but not in Groups R and L while HR was significantly increased following intubation in the three groups. Conclusion： Epidural anesthesia with 1.5% lidocaine and 0.5% ropivacaine has similar effects on the time to LOC, effect-site propofol concentrations, total propofol dose, and the hemodynamic variables during induction of general anesthesia.

Efficacy of Bispectral index-monitored closed-loop targeted-controlled infusion of propofol for laparoscopic radical operation for gastric cancer

Objective:To discuss the efficacy of Bispectral index (BIS)-monitored closed-loop targeted-controlled infusion of propofol for laparoscopic radical operation for gastric cancer.Methods:A total of 106 patients with primary gastric cancer who underwent laparoscopic radical operation for gastric cancer in our hospital between August 2015 and February 2018 were chosen as the research subjects and divided into the control group (n=53) and the observation group (n=53) according to the different anesthesia methods. Control group of patients received BIS-monitored manually adjusted targeted-controlled infusion concentration of propofol, and observation group of patients received BIS-monitored closed-loop targeted-controlled infusion of propofol. The differences in hemodynamic index levels as well as serum contents of inflammatory factors and stress hormones were compared between the two groups of patients before anesthesia (T0), 30 min after surgery started (T1) and 30 min before surgery ended (T2).Results:At T0, the differences in hemodynamic index levels as well as serum contents of inflammatory factors and stress hormones were not statistically significant between the two groups. At T1 and T2, hemodynamic indexes MAP and HR levels of observation group were lower than those of control group at the corresponding time points;serum inflammatory factors sICAM-1, IL-1β, IL-8 and TNF-α contents were lower than those of control group at the corresponding time points;serum stress hormones Cor, T4 and glucagon contents were lower than those of control group at the corresponding time points.Conclusion: BIS-monitored closed-loop targeted-controlled infusion of propofol can effectively stabilize the intraoperative hemodynamics and inhibit the systemic inflammatory stress response in patients with laparoscopic radical operation for gastric cancer.

Comparison of Entropy vs. Bispectral Index Anesthetic Depth Monitoring during Isoflurane Anesthesia in Living Donor Liver Transplantation: Observational Study

Liver transplantation (LT) recipients are known to require less anesthetic agents. Providing minimally required anesthetics while avoiding awareness is especially important in LT recipients because it would help manage perioperative hemodynamic instability with less vasopressor and fast track recovery. This study aims to compare state entropy (SE) against bispectral index (BIS) during isoflurane anesthesia in LT. We adjusted anesthesia to BIS values 40 - 60, and compared it with concomitant SE values. BIS, SE values, and anesthetic requirements according to liver failure severity, etiology and LT stages were analyzed. For BIS-SE differences, SE value that is different from the concomitant BIS by more than 15 was defined as a significant disagreement. Mann Whitney, Kruskal Wallis test and a Poisson exact test were used for analysis. The BIS-SE pair sets of 2895 from 38 patients were analyzed. BIS, SE values and anesthetic requirements were significantly lower in MELD ≥ 20 (p < 0.001 in all) and in alcoholic etiology (p < 0.001 in all). For BIS-SE differences, 320 disagreement data pairs were seen at a rate of 1.33 times/hr (95% CI = [1.19, 1.48], p < 0.001). A significant disagreement was delineated in MELD score ≥ 20 (3.04 times/hr, CI = [2.64, 3.49], p < 0.001), alcoholic etiology (3.19 times/hr, [2.67, 3.78], p < 0.001) and postreperfusion stage (1.63 times/hr, [1.43, 1.85], p < 0.001). In these significant BIS-SE differences, 95.9% (307/320 disagreement data pairs) showed higher BIS than SE. In conclusion, in high MELD and alcoholic etiology, anesthetic requirements were significantly less, and BIS and SE showed great discrepancy with lower SE values. Therefore, when SE monitoring is used during LT, anesthesiologists may need to consider that in high MELD and alcoholic etiology, SE tends to show lower values than the concomitant BIS values that are within optimal anesthetic depth ranges.

The Bispectral Index Interest during General Anesthesia at the University Hospital of Parakou (Republic of Benin) in 2019

Background: The bispectral index (BIS) derived from the electroencephalogram is an additional means of monitoring the depth of narcosis. Objective: To compare the monitoring of the depth of narcosis by the BIS associated with clinical data versus standard monitoring at the University Hospital of Parakou in Benin in 2019. Methods: This was an observational study for descriptive and analytical purposes with prospective data collection, carried out in general surgery and intensive care unit for 4 months. The inclusion criteria were: an age ≥ 18 years, an ASA score ≤ 3, surgery under general anesthesia and informed consent of the patient. Two groups were formed: non-BIS group monitored by clinical parameters (PA, FC, FR, EtCO2, and SpO2) only and BIS group monitored by bispectral index in addition to clinical parameters. Patients were seen 48 hours after the procedure. Results: 36 patients were collected. The mean age was 40.63 ± 16.77 years with a sex ratio of 3. ASA 1 patients represented 86.11% of the sample and ASA2 patients 13.89%. The average doses of Propofol were not significantly reduced in the BIS group (p = 0.555). On the other hand, the period of intraoperative recovery (p-value = 0.007) and the NVPO (p = 0.043;OR = 0.10;95% CI [0.01 - 0.97]) were significantly reduced by the use of BIS. One case of intraoperative memorization (2.78%) was however found in the BIS group. Conclusion: The bispectral index makes it possible to significantly reduce the risk of intraoperative awakening and PONV, and not significantly reduce the consumption of Propofol.

rSO2-BIS监测在儿童肱骨髁上骨折手术中的应用研究

目的 探讨局部脑氧饱和度(regional cerebral oxygen saturation,rSO2)-脑电双频指数(bispectral index,BIS)监测麻醉方式在儿童肱骨髁上骨折手术中的应用。方法 选取江西省儿童医院骨科2020年1月至2022年12月收治的60例肱骨髁上骨折手术患儿,按随机数字表法分为对照组和观察组,每组30例。观察组患儿麻醉后给予rSO2-BIS监测,对照组患儿给予常规麻醉管理。结果 观察组患儿的丙泊酚中/长链脂肪乳和瑞芬太尼注射液用量明显少于对照组(P<0.05);患儿苏醒时各时间点的心率、血氧饱和度及平均动脉压比较,差异无统计学意义(P>0.05);术后镇痛药补救率低于对照组,拔管时间短于对照组(P<0.05);术后不良反应发生率及不良行为率低于对照组(P<0.001)。多因素分析结果发现丙泊酚中/长链脂肪乳和瑞芬太尼注射液的用量是诱发患儿术后出现不良反应和不良行为的独立危险因素,rSO2-BIS监测是减少患儿术后出现不良行为和不良反应的关键因素(P<0.05)。结论 儿童肱骨髁上骨折术中采用rSO2-BIS监测可降低手术患儿术后不良行为和不良反应的发生率,进而改善术后疗效。

BIS指导下丙泊酚联合瑞芬太尼靶控输注对老年髋关节置换患者术中丙泊酚用量和术后谵妄发生率的影响

目的:探讨脑电双频指数(BIS)指导下丙泊酚联合瑞芬太尼靶控输注(TCI)对老年髋关节置换患者术中丙泊酚用量和术后谵妄发生率的影响。方法:回顾性分析老年髋部骨折患者的病例资料,依据患者接受的麻醉方式不同分为两组,即接受BIS指导下丙泊酚联合瑞芬太尼TCI麻醉的髋关节置换患者纳入观察组,接受BIS指导下丙泊酚联合瑞芬太尼持续静脉泵入的同类患者纳入对照组,建立二元Logistics回归分析,构建倾向性评分匹配模型分析得出观察组获取56例病例资料,对照组获取49例病例资料,组间差异无统计学意义(P>0.05)。观察两组不同时间点[入室后(T_(0))、麻醉后(T_(1))、骨水泥后(T_(2))、术毕(T_(3))、出室后(T_(4))、术后3h(T_(5))及术后5h(T_(6))时刻]的平均动脉压(MAP)、心率(HR)、手术一般情况、丙泊酚用量、BIS值维持情况,对比两组不同时间点(术前及术后1h、6h、1d、3d、7d时刻)谵妄评分[谵妄量表分析系统(CAM-CR)],记录两组术后谵妄发生率,比较两组不同时间点(术前及术后1d)的血糖(Glu)及血浆肾上腺素(E)、皮质醇(Cor)水平变化。结果:观察组在T_(1)时刻MAP值相比T_(0)时刻有显著性降低(P<0.05),两组均在T_(2)时刻MAP值相比T_(0)时刻有显著性降低(P<0.05),其中对照组在T_(5)、T_(6)及T_(7)时刻HR值相比T_(4)时刻出现显著性降低(P<0.05);两组手术时间、麻醉时间及术中出血量对比均差异无统计学意义(P>0.05),观察组丙泊酚用量显著少于对照组(P<0.05),观察组BIS值目标范围维持时间比显著高于对照组(P<0.05),观察组苏醒时间、气管拔管时间及定向力恢复时间显著短于对照组(P<0.05);术后1h、6h、1d、3d、7d,两组CAM-CR评分可见先升高后降低,均显著高于术前(P<0.05),观察组术后1h、6h、1d、3d的CAM-CR评分均显著低于对照组(P<0.05),两组术后7d的上述评分较术前和组间同时间点对比均差异无统计学意义(P>0.05);观察组的术后谵妄发生率为5.36%,显著低于对照组的18.37%(P<0.05);术后1d,两组Glu及血浆E、Cor水平相比术前出现显著性升高(P<0.05),但观察组显著低于对照组(P<0.05)。结论:BIS指导下丙泊酚联合瑞芬太尼TCI应用于老年髋关节置换患者术中能稳定血流动力学,改善围手术期指标,并减少丙泊酚用量,改善BIS值维持情况,并促进患者麻醉恢复,减少术后谵妄发生风险,同时能减轻机体应激反应。

BIS指导下七氟烷吸入在小儿腹腔镜疝囊高位结扎术中的应用价值

目的:探讨脑电双频指数(BIS)指导下七氟烷吸入麻醉在小儿腹腔镜疝囊高位结扎术中的应用的临床价值。方法:选取2020年6月~2022年10月九江市第一人民医院拟实施七氟烷吸入麻醉下腹腔镜疝囊高位结扎术的小儿120例,采用随机数字表法分为BIS组60例(BIS术中维持在40~50)、对照组60例(由麻醉师根据患儿情况调节麻醉药物使用);对比BIS组和对照组患儿不同时间的心率(HR)、平动动脉压(MAP)、血氧饱和度(SpO_(2))及BIS组和对照组患儿的意识消失时间、喉罩置入时间、拔除喉罩时间、苏醒时间、麻醉复苏室(PACU)停留时间、七氟烷使用量、不良反应情况。结果:经重复测量的方差分析法分析,BIS组和对照组的HR、MAP组间差异具有统计学意义(P<0.05),BIS组的HR、MAP测定值波动较对照组小;BIS组和对照组的SpO_(2)测定值差异无统计学意义(P>0.05);BIS组和对照组的意识消失时间、喉罩置入时间组间差异无统计学意义(P>0.05),BIS组的苏醒时间、拔除喉罩时间、PACU停留时间、七氟烷使用量测定值低于对照组,差异有统计学意义(P<0.05);BIS组患者的不良反应发生率(6.67%)明显低于对照组(20.00%),差异有统计学意义(P<0.05)。结论:BIS指导下七氟烷吸入麻醉在小儿腹腔镜疝囊高位结扎术中的应用可减小七氟烷用量、更好的维持术中血流动力学的稳定。

rSO_(2)-BIS目标导向麻醉管理对非急性期脆弱脑功能患者术后认知功能的影响研究

目的 观察局部脑氧饱和度(rSO_(2))-脑电双频谱指数(BIS)目标导向麻醉管理对非急性期脆弱脑功能患者术后认知功能的影响。方法 70例非急性期脆弱脑功能患者,按照麻醉管理方式不同分为对照组与实验组,各35例。对照组实施BIS目标导向麻醉管理,实验组实施rSO_(2)-BIS目标导向麻醉管理。比较两组不同时刻血流动力学参数、认知功能、进手术室时(T0)及术后2 d(T5)时的视觉模拟评分法(VAS)评分、并发症发生情况。结果 T0时,两组心率、平均动脉压比较,差异无统计学意义(P>0.05);与T0时比较,麻醉诱导后(T1)、插管后即刻(T2)、切皮时(T3)、手术结束时(T4)两组的心率、平均动脉压均降低,但实验组高于同期对照组,差异有统计学意义(P<0.05)。实验组术后谵妄(POD)发生率5.71%低于对照组的22.86%, POD持续时间(16.5±0.7)h短于对照组的(20.5±1.4)h,差异均有统计学意义(P<0.05)。两组术后认知功能障碍(POCD)发生率比较,差异无统计学意义(P>0.05)。T5时,两组VAS评分均高于T0时,但实验组VAS评分(3.43±0.08)分低于对照组的(5.13±0.11)分,差异有统计学意义(P<0.05)。实验组并发症发生率5.71%低于对照组的22.86%,差异有统计学意义(P<0.05)。结论 非急性期脆弱脑功能患者采用rSO_(2)-BIS目标导向麻醉管理效果显著优于BIS目标导向麻醉管理。

BIS监测下瑞马唑仑复合丙泊酚在老年髋关节脱位手法复位中的应用效果

目的探究脑电双频指数(BIS)监测下瑞马唑仑复合丙泊酚在老年髋关节脱位手法复位中的应用效果。方法前瞻性选取2021年1月至2022年12月商洛市中医医院收治的75例需行手法复位的老年髋关节脱位患者作为研究对象。男44例,女31例;年龄60~85岁;美国麻醉医师协会(ASA)分级Ⅰ~Ⅱ级;体重指数(BMI)18.2~25.1 kg/m2。采用随机数字表法,将患者分为A组(25例)、B组(25例)、C组(25例)。3组均行静脉全身麻醉,A组采用丙泊酚麻醉(静脉注射),B组采用瑞马唑仑麻醉(静脉注射),C组采用瑞马唑仑复合丙泊酚麻醉(静脉注射)。比较3组麻醉效果(麻醉诱导时间、麻醉苏醒时间、麻醉恢复时间、复位时间)、血流动力学指标[平均动脉压(MAP)、心率(HR)]、应激指标[皮质醇(Cor)、肾上腺素、神经肽Y(NPY)]及不良反应(低血压、心动过缓、呼吸抑制、恶心呕吐、注射痛)。采用方差分析、LSD-t检验、χ^(2)检验和Fisher确切概率法。结果3组复位时间比较,差异无统计学意义(P>0.05);C组麻醉诱导时间[(62.31±4.15)s]、苏醒时间[(17.26±3.45)min]、恢复时间[(6.25±1.56)min]均短于A组[(68.47±4.56)s、(21.47±4.29)min、(9.48±1.89)min]、B组[(69.85±4.66)s、(22.36±4.47)min、(9.24±1.85)min](均P<0.05);A组与B组麻醉诱导时间、苏醒时间、恢复时间比较,差异均无统计学意义(均P>0.05)。复位中、复位后,C组MAP[(85.77±4.29)mmHg(1 mmHg=0.133 kPa)、(85.36±4.27)mmHg]、HR[(75.21±3.76)次/min、(75.68±3.78)次/min]水平均低于A组[(89.29±4.46)mmHg、(88.73±4.44)mmHg、(79.24±3.96)次/min、(80.15±4.02)次/min]、B组[(90.21±4.51)mmHg、(89.56±4.47)mmHg、(78.33±3.93)次/min、(79.66±3.98)次/min](均P<0.05);A组与B组MAP、HR水平比较,差异均无统计学意义(均P>0.05)。复位后,C组Cor[(291.42±32.38)nmol/L]、肾上腺素[(211.47±14.11)μg/L]、NPY[(118.41±14.81)μg/L]水平均低于A组[(326.85±36.32)nmol/L、(231.46±15.43)μg/L、(137.65±17.21)μg/L]、B组[(321.54±34.73)nmol/L、(228.75±15.25)μg/L、(135.24±16.91)μg/L](均P<0.05);A组与B组Cor、肾上腺素、NPY水平比较,差异均无统计学意义(均P>0.05)。A组不良反应总发生率[56.00%(14/25)]高于B组[16.00%(4/25)]、C组[12.00%(3/25)](均P<0.05);B组与C组不良反应总发生率比较,差异无统计学意义(P>0.05)。结论在BIS监测下瑞马唑仑复合丙泊酚用于老年髋关节脱位患者手法复位麻醉,不仅可减少用药剂量,还可增强麻醉效果,促进镇痛,且安全性良好。

BIS监测在老年骨科全麻手术中的应用分析

目的探讨脑电双频谱指数(Bispectral Index,BIS)监测在老年骨科全麻手术中的应用效果。方法非随机选取2022年8月—2023年11月呈贡区人民医院接受骨科全麻手术治疗的老年患者90例,按监测方法不同分为两组。研究组(n=45)行BIS监测下调节麻醉诱导及维持用药,对照组(n=45)行常规诱导和维持麻醉。比较两组麻醉用药剂量、术后恢复指标、血流动力学指标[平均动脉压(Mean Arterial Pressure,MAP)、心率(Heart Rate,HR)、血氧饱和度(Puise Oxygen Saturation,SpO_(2))]水平变化及术后认知功能障碍发生情况。结果研究组麻醉用药剂量及术后恢复指标均优于对照组,差异有统计学意义(P均<0.05)。研究组患者MAP、HR变化水平比对照组更稳定,差异有统计学意义(P均<0.05)。两组SpO_(2)水平比较,差异无统计学意义(P均>0.05)。术后1、3 d,研究组术后认知功能障碍发生率分别为4.44%、0,均低于对照组17.78%、13.33%,差异有统计学意义(χ^(2)=4.050、4.464,P均<0.05)。结论BIS监测能减少老年骨科全麻手术患者麻醉药物用量,有利于提高苏醒质量及血流动力学稳定性,降低术后认知功能障碍的发生率。

Comparison of Correlation Dimension and Fractal Dimension in Estimating BIS index

This paper compares the correlation dimension (D2) and Higuchi fractal dimension (HFD) approaches in estimating BIS index based on of electroencephalogram (EEG). The single-channel EEG data was captured in both ICU and operating room and different anesthetic drugs, including propofol and isoflurane were used. For better analysis, application of adaptive segmentation on EEG signal for estimating BIS index is evaluated and compared to fixed segmentation. Prediction probability (PK) is used as a measure of correlation between the predictors and BIS index to evaluate the proposed methods. The results show the ability of these algorithms (specifically HFD algorithm) in predicting BIS index. Also, evolving fixed and adaptive windowing methods for segmentation of EEG reveals no meaningful difference in estimating BIS index.

右美托咪定对冠状动脉旁路移植术患者麻醉诱导期BIS和血流动力学的影响

目的观察新型α2肾上腺素受体激动剂右美托咪定对冠状动脉旁路移植术（coronary artery bypass grafting,CABG）麻醉诱导期患者脑电双频谱指数（bispectral index,BIS）及血流动力学的影响。方法 2010年6月11日~7月30日30例择期CABG（年龄50~70岁,ASAⅠ~Ⅱ级,心功能Ⅱ~Ⅲ级）随机双盲分为2组：Dex组（n=15）,右美托咪定1μg.kg-1,稀释30 ml静脉泵注（15 min）,继以0.5μg.kg-1.h-1维持输注;对照组（n=15）,生理盐水30 ml,方法同Dex组。监测BIS值,收缩压（systolic blood pressure,SBP）、舒张压（diastolic blood pressure,DBP）、平均动脉压（mean arterial pressure,MAP）、心率（heart rate,HR）,以给药前（T0）、给药后3 min（T1）、6 min（T2）、9 min（T3）、12 min（T4）、15 min（T5）、插管前（T6）、插管结束后1 min（T7）、插管结束后3 min（T8）作为观察记录点。结果麻醉前2组BIS值分别为94.8±2.8和96.3±2.9,无统计学差异（t=-1.441,P=0.161）;与给药前比较,Dex组给药后BIS值逐渐下降,9 min后（T3）下降至84.8±9.7（P=0.034）,15 min后（T5）下降至71.4±13.6（P=0.000）;对照组给药后15 min（T5）BIS值为90.9±4.1,与给药前比较无明显变化,但显著高于Dex组（t=-5.317,P=0.000）。Dex组给药后15 min后（T5）HR明显减慢,由给药前（T0）（64.7±16.4）次/min减至（57.0±11.9）次/min（P=0.024）,但与对照组无明显差异（P〉0.05）;MAP由（101.2±15.1）mm Hg到（100.8±18.8）mm Hg,无明显变化（P=0.927）。麻醉诱导期间,对照组插管后SBP、DBP、MAP、HR值较插管前均有升高,插管后1 min（T7）上述各指标分别为（136.1±36.6）mm Hg（P=0.130）,（75.3±15.5）mm Hg（P=0.000）,（94.4±20.0）mm Hg（P=0.000）,（66.2±13.7）次/min（P=0.009）,插管后3 min（T8）上述各指标分别为（143.5±30.5）mm Hg（P=0.003）,（71.4±12.1）mm Hg（P=0.002）,（92.4±14.8）mm Hg（P=0.002）,（60.1±13.0）次/min（P=0.387）;但Dex组无明显变化（P〉0.05）。结论右美托咪定以负荷剂量1.0μg.kg-1继以0.5μg.kg-1.h-1维持输注对CABG患者产生明显镇静效应,能使BIS值降低,同时降低心率,能维持麻醉诱导期间的血流动力学稳定,减轻插管反应。

BIS监测预防全凭静脉麻醉下术中知晓的多中心研究

目的 评估BIS监测在丙泊酚全凭静脉麻醉（total intravenous anesthesia,TIVA）下预防术中知晓的作用,探讨术中知晓的可能原因。方法 采用多中心、大样本、前瞻性的随机、双盲、分组对照研究方法,患者（年龄≥16岁）被随机分为BIS监测指导组（A组,监测并维持BIS值40-60）和对照组（B组,监测BIS但遮挡显示屏）。分别于术后第1天和第4天随访,由独立的评估委员会作明确和可疑知晓的判断。术后间隔一定时间导出BIS数据,分析明确知晓病例的BIS趋势以判断是否存在浅麻醉。明确两组知晓的发生率。结果 共收集5 228例有效病例,其中A组2 919例,B组2 309例。明确知晓病例A组4例（0.14%）,B组15例（0.65%）,两组比较差异有统计学意义（P=0.002,OR=0.21,95%置信区间：0.07-0.63）。两组可疑知晓（A组0.14%,B组0.26%,P=0.485）和做梦（A组3.1%,B组3.1%,P=0.986）的发生率差异无统计学意义。19例明确知晓病例的术中BIS趋势和麻醉总结显示,8例（A组3例,B组5例）无BIS及知晓原因分析;6例获取了相应的BIS趋势图,其中5例（A组1例,B组4例）BIS趋势提示有明确浅麻醉表现,1例（B组）BIS基本稳定于60及以下;其余5例（B组）知晓经主管麻醉医生回顾,有术中浅麻醉和BIS波动且升高〉60的情况。结论 行BIS监测并维持BIS值40-60可有效减少TIVA术中知晓的发生。发生知晓的主要原因为术中浅麻醉。

BIS监测麻醉深度对老年腹腔镜胆囊切除术患者苏醒质量的影响

目的 探讨脑电双频指数（BIS）监测麻醉深度对老年腹腔镜胆囊切除术（LC）患者苏醒质量的影响。方法 90例择期拟行LC的老年患者,分为BIS监测组（B组）和传统经验组（T组）,每组45例。两组均监测BIS,B组维持期参考BIS值调节给药,T组根据血流动力学和临床经验调节给药。记录并比较两组呼唤睁眼时间（T1）、意识完全恢复时间（T2）、拔除喉罩时间（T3）及Steward苏醒评分大于4分的时间（T4）、拔除喉罩后即刻（t0）、1min（t1）、3min（t3）、5min（t5）的改良OAA/S评分及Steward苏醒评分和苏醒期躁动及术后24h术中知晓情况,统计丙泊酚用量。结果 B组丙泊酚用量明显少于T组,T1-T4均明显缩短于T组（P〈0.05）,t1、t3改良OAA/S评分、t5Steward苏醒评分均明显高于T组（P〈0.05）;B组无躁动,T组2例躁动,差异无统计学意义（P〉0.05）;术后24h回访两组均无术中知晓。结论 与T组比较,LC应用BIS监测麻醉深度可减少丙泊酚用量,缩短苏醒时间,有助于提高老年患者苏醒质量。

BIS和AEPI监测镇静深度的评价

目的比较脑电双频指数(BIS)和听觉诱发电位指数(AEPI)在丙酚靶控镇静深度的临床价值。方法45例腰-硬联合麻醉术中需丙泊酚镇静病人,ASAⅠ级,腰麻平面确定后开始丙泊酚靶控输注镇静。结果(1)丙泊酚镇静期BIS、AEPI逐渐降低,苏醒期逐渐升高(P<0.01),而AEPI则在意识转换过程中变化更敏感(P<0.01)。(2)在丙泊酚镇静期和苏醒期BIS、AEPI与丙泊酚EC密切相关。(3)在丙泊酚镇静期,联合监测当BIS≤63和AEPI≤30时敏感度即可达100%。结论BIS和AEPI是监测麻醉镇静深度的良好指标,BIS和AEPI联合监测提高了诊断的敏感度。

全身麻醉中肌电活动的变化对BIS监测准确性的影响

目的 探讨全麻维持过程中 ,肌电活动变化对双频谱指数 (BIS)监测准确性的影响。方法 14例ASAⅠ～Ⅱ妇科择期手术患者以异丙酚 (血浆靶浓度 :3 5 μg/ml)、芬太尼 (3μg/kg)、万可松 (0 1mg/kg)行诱导插管 ;之后 ,调整异丙酚血浆靶浓度以维持BIS值在 4 0～6 0之间 ,固定此靶浓度不变。持续监测双频谱指数 (BIS)、肌电图 (EMG)、信号质量指数 (SQI)。在保持异丙酚血浆靶浓度不变的情况下 ,随着肌松作用的减退 ,BIS逐渐升高 ,当满足观察条件 (BIS>70持续 30s以上 ,且EMG >4 0 )时 ,记录此后 5min内的BIS、EMG、SQI、平均动脉压 (MAP)、心率 (HR) ;随后静注追加万可松 0 0 5mg/kg并记录此后 10min内上述参数值。结果 静注万可松 3min后 ,BIS值显著降低 (P <0 0 0 1) ,EMG降低 (P <0 0 5 ) ,SQI升高 (P <0 0 5 ) ;各观察点MAP、HR差异无显著性 (P >0 0 5 )。结论 在麻醉维持过程中 ,肌松作用减退导致的肌电活动增加可引起BIS假性升高 ,从而影响BIS监测的准确性。

右美托咪定镇静时BIS与OAA/S评分的相关性研究

目的探讨右美托咪定镇静时BIS与OAA/S评分的相关性。方法选择腰-硬联合麻醉下行单侧膝关节镜手术患者60例,ASAⅠ或Ⅱ级。随机分为三组:右美托咪定组(D组)、丙泊酚组(P组)和咪达唑仑组(M组),每组20例。每组镇静药物均连续三阶段输注,每阶段维持40min。D组:第一阶段负荷量加维持量,负荷量1.0μg/kg,15min恒速输注完毕,维持量0.5μg·kg-1·h-1,第二、三阶段维持量分别为1.0、1.5μg·kg-1·h-1。P组:三阶段效应室靶控浓度分别为1.0、2.0、4.0μg/ml。M组:三阶段药物浓度分别0.05、0.1、0.15mg·kg-1·h-1。三组药物输注的120min内,每隔5分钟记录一次BP、HR、SpO2、BIS值,分析OAA/S评分与BIS的相关性(r)和BIS对OAA/S评分的预测概率(Pk)。结果与基础值比较,OAA/S评分≤3时三组SBP明显降低、OAA/S评分≤4分时D组HR明显减慢(P<0.05)。与D组比较,OAA/S评分≤3分时M组SBP明显升高、OAA/S评分≤4分时P组和M组HR明显增快(P<0.05)。与OAA/S评分5分时比较,OAA/S评分≤4分时三组患者BIS明显降低(P<0.05)。与D组比较,OAA/S评分≤4分时P组和M组BIS值明显升高(P<0.05)。三组患者BIS与OAA/S评分呈正相关,且Pk值均大于0.5(P<0.05)。结论右美托咪定镇静时BIS与OAA/S评分具有较好相关性,可作为评价右美托咪定镇静深度的重要指标;但其相关性较丙泊酚、咪达唑仑差。