Vecuronium infusion requirements in pediatric patients during fentanyl-N2O-O2 anesthesia

Eighty-one pediatric patients, ranging from neonates to adolescents, were studied during fentanyl-N2O-O2 anesthesia to determine for each of them the vecuronium infusion required to maintain 90-95% neuromuscular block (NMB). Electromyographic monitoring with train-of-four stimuli was used. The steady infusion rate was 62 +/- 15 (SD) micrograms.kg-1.hr-1 in neonates and infants. This rate was 40% of that required by children 3 to 10 years old (154 +/- 49 micrograms.kg-1.hr-1; P less than 0.05). In adolescents the vecuronium requirement was less than in children and was comparable to that reported in adults in other studies (89 +/- 13 micrograms.kg-1.hr-1). Despite considerable individual variation, the infusion rate could be reliably estimated on the basis of duration of greater than 90% NMB maintained by small doses of vecuronium given after intubation. Also, a close correlation existed between the duration of greater than 90% NMB maintained by 100 micrograms/kg of vecuronium and the individual infusion rate (r2 = 0.76).     

Continuous opioid infusions for neurosurgical procedures: a double-blind comparison of alfentanil and fentanyl

The ability of continuous infusions of opioids to control hypertension at the end of neurosurgical procedures without compromising prompt emergence was studied in patients undergoing craniotomy for supratentorial tumours. Four infusion regimens were compared in a randomized double-blind fashion; three of alfentanil and one of fentanyl. Low-dose alfentanil was administered to nine patients (35.1 micrograms.kg-1 then a continuous infusion of 16.2 micrograms.kg-1.hr-1); mid-dose alfentanil to eight patients (70.2 micrograms.kg-1 then 32.4 micrograms.kg-1.hr-1); high-dose alfentanil to eight patients (105.3 micrograms.kg-1 then 48.6 micrograms.kg-1.hr-1). Eight additional patients were given fentanyl (8.3 micrograms.kg-1 then 1.6 micrograms.kg-1.hr-1). Using published values for the pharmacokinetic variables of alfentanil and fentanyl, modelling predicted stable concentrations of 60, 120, 180 ng.ml-1 for the alfentanil infusion regimens respectively and 2 ng.ml-1 with the fentanyl regimen. Maintenance anaesthesia comprised the opioid infusion, 50% N2O in O2 and isoflurane titrated to control mean arterial pressure (MAP) within 20% of ward MAP. Isoflurane was discontinued after closure of the dura. Nitrous oxide was discontinued at the same time as reversal of neuromuscular blockade. The opioid infusion was discontinued with closure of the galea. A greater time-averaged isoflurane concentration was required to control MAP within the prescribed limits in the low alfentanil group (ANOVA; P less than 0.05). The PaCO2 at two, five and 30 min after extubation were not different among groups. The times from discontinuing N2O to eye opening and tracheal extubation were not different. The time to follow commands was longer in the low alfentanil group (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

双心房输注对二尖瓣置换术患者体外循环后肺动脉压的影响

目的 评价双心房输注对二尖瓣置换术患者体外循环后肺动脉压(PAP)的影响.方法 择期行二尖瓣置换术合并肺动脉高压[平均肺动脉压(MPAP)＞50 mm Hg]的患者20例,年龄22～53岁,体重34～57kg,心功能分级Ⅱ或Ⅲ级,随机分为2组(n=10):右心房输注组(R组)和双心房输注组(B组).麻醉诱导后右颈内静脉穿刺置入Swan-Ganz三腔漂浮导管,监测CVP、PAP、肺毛细血管楔压(PCWP)和CO.R组经中心静脉输注前列腺素E130～150 ng·kg-1·min-1和去氧肾上腺素0.2～0.6μg·kg-1·min-1.B组经中心静脉输注前列腺素E130～150 ng·kg·min-1,经左心房输注去氧肾上腺素0.2～0.6μg·kg-1·min-1.分别于给药前5 min(T0)、给药后5 min(T1)、10 min(T2)、30 min(T3)和60 min(T4)时记录MAP、HR、MPAP、PCWP、CVP和CO,计算肺血管阻力指数(PVRI)、体循环血管阻力指数(SVRI)和CI.结果 与T0时比较,R组T1-4时MAP、MPAP、PCWP和PVRI降低,CI升高(P＜0.05),HR、CVP和SVRI差异无统计学意义(P＞0.05),B组T1-4时MAP、CI和SVRI升高,HR、MPAP、PCWP、CVP和PVRI降低(P＜0.05);与R组比较,B组MAP、CI和SVRI升高,HR、MPAP、PCWP、PVRI和CVP降低(P＜0.05).结论 双心房输注可降低二尖瓣置换术患者体外循环后肺动脉压和肺血管阻力.     

Low-dose synthetic narcotic infusions for cerebral relaxation during craniotomies

Thirty patients undergoing craniotomies were given infusions of fentanyl 1 microgram X kg-1 X hr-1, sufentanil 0.1 microgram X kg-1 X hr-1, or normal saline in a double-blind study of cerebral relaxation. Significantly better relaxation scores were achieved in patients given a narcotic infusion, but there was no difference between the scores with the two narcotics. Infusions of narcotics at these low rates did not delay recovery or alter the requirement for other anesthetic agents. Narcotic infusion rates that do not delay recovery or alter depth of anesthesia significantly improve cerebral relaxation.     

复合异丙酚全麻中麻醉深度指标的相关性

目的 探讨复合异丙酚全麻中麻醉深度指标的相关性。方法 选择ASA Ⅰ～Ⅱ择期手术患者18例,行血压、心率、脑电、心率变异性监测,并测定异丙酚血药浓度。调整异丙酚的泵注速度,使收缩压(SBP)的波动幅度≤20％基础值,双频谱指数(BIS)维持在30～60之间。结果 异丙酚血药浓度与BIS、平均动脉压(MAP)有负相关关系(P<0.01),相关程度为BIS>MAP,心率(HR)与MAP呈正相关(P<0.01);心率变异性低频(LF)、高频(HF)与HR均有负相关关系(P<0.01),LF与HF有正相关关系(P<0.01),LF、HF与MAP、BIS、异丙酚血药浓度无相关关系(P>005)。结论 LF、HF可反映心脏交感、迷走张力的活动变化,而不能反映麻醉的意识状态。可通过BIS、平均动脉压来调整异丙酚血药浓度。     

Vecuronium infusion dose requirements during fentanyl and halothane anesthesia in humans

Steady-state infusion rate requirements of vecuronium were determined in 29 patients during either halothane-nitrous oxide or fentanyl-nitrous oxide anesthesia at different levels of neuromuscular block. During N2O-halothane anesthesia (end-tidal concentration, 0.5%), the infusion rate necessary for a steady-state (defined as unchanging twitch height and infusion rate for at least 20 min) 50% depression of twitch force was 28.8 +/- 5.4 (mean +/- SD) (n = 8) and 47.6 +/- 9.7 micrograms . kg-1 . hr-1 (n = 6) at 90% reduction of twitch force. During N2O-fentanyl anesthesia, the steady-state infusion rate required for 50 and 90% decrease of twitch force was 56.3 +/- 20.0 (n = 9) and 74.8 +/- 16.0 micrograms . kg-1 . hr-1 (n = 6), respectively. The variances of vecuronium steady-state infusion dose requirements were smaller in the halothane groups than in the fentanyl anesthesia groups. The steady-state vecuronium infusion dose requirements during fentanyl anesthesia were greater than the mean infusion dose requirements during halothane anesthesia at equivalent levels of twitch depression.     

Neuromuscular and cardiovascular effects of mivacurium chloride in surgical patients receiving nitrous oxide-narcotic or nitrous oxide-isoflurane anaesthesia

The neuromuscular and cardiovascular effects of mivacurium chloride were studied during nitrous oxide-oxygen narcotic (fentanyl) (n = 90) and nitrous oxide-oxygen isoflurane (ISO) anaesthesia (n = 45). In addition, a separate group (n = 9) received succinylcholine during fentanyl anaesthesia to compare its neuromuscular effects with mivacurium. Mivacurium was initially administered as a single bolus in doses from 0.03 mg.kg-1 to 0.25 mg.kg-1 to study the dose-response relationships, as well as the cardiovascular effects of mivacurium. Neuromuscular block (NMB) was measured by recording the twitch response of the adductor pollicis muscle following ulnar nerve stimulation (0.15 Hz, 0.2 ms supramaximal voltage). The ED95 values for mivacurium were estimated to be 0.073 mg.kg-1 and 0.053 mg.kg-1 in the fentanyl and ISO groups respectively. The duration of block (time from injection to 95 per cent recovery) for a dose of 0.05 mg.kg-1 mivacurium was 15.3 +/- 1.0 min and 21.5 +/- 1.3 min for fentanyl and ISO anaesthesia, respectively. The recovery index (25-75 per cent) between initial bolus dose (6.1 +/- 0.5 min), repeat bolus doses (7.6 +/- 0.6 min), mivacurium infusion (6.7 +/- 0.7 min) and succinylcholine infusion (6.8 +/- 1.8 min) were not significantly different. There was minimal change in mean arterial pressure (MAP) or heart rate (HR) following bolus doses of mivacurium up to 0.15 mg.kg-1. Bolus administration of 0.20 mg.kg-1 or 0.25 mg.kg-1 of mivacurium decreased MAP from 78.2 +/- 2.5 to 64.0 +/- 3.2 mmHg (range 12-59 per cent of control) (P less than 0.05). The same doses when administered slowly over 30 sec produced minimal change in MAP or HR.     

Esmolol for potentiation of nitroprusside-induced hypotension: impact on the cardiovascular, adrenergic, and renin-angiotensin systems in man

Esmolol infusion at rates of 200, 300, and 400 micrograms.kg-1.min-1 was used to potentiate hypotension (mean arterial pressure = 60 mm Hg) induced with sodium nitroprusside (SNP) in 10 male patients undergoing radical cancer surgery during nitrous oxide-oxygen and fentanyl anesthesia. Heart rate (HR), blood pressure (radial arterial catheter), and plasma levels of renin activity (PRA), norepinephrine (N), epinephrine (E), and dopamine (D) were measured: 1) while patients were awake; 2) after induction of anesthesia (nitrous oxide, 60% in oxygen, fentanyl = 5 micrograms/kg followed by an infusion at 10 micrograms.kg-1.hr-1); 3) after surgery had begun; 4) after 20 minutes of SNP-induced hypotension; 5) after 20 minutes of esmolol at each of the above infusion rates; and 6) after the completion of surgery. Compared to awake values, SNP-induced hypotension (mean infusion rate = 3.1 micrograms.kg-1.min-1 +/- 0.6 SE) during surgery resulted in significant (P less than 0.05) increases in heart rate, PRA, N, and D. Infusion of esmolol resulted in significant (P less than 0.05) dose-dependent reductions in SNP requirement to maintain MAP = 60 mm Hg. At 200 micrograms.kg-1.min-1, SNP requirement was 2.1 micrograms.kg-1.min-1 +/- 0.4, at 300 micrograms.kg-1.min-1, it was 1.0 micrograms.kg-1.min-1 +/- 0.2, and at 400 micrograms.kg-1.min-1, was 0.5 micrograms.kg-1.min-1 +/- 0.3. Concomitant with the decrease in SNP requirement, there were significant reductions in HR and PRA at all infusion rates of esmolol.(ABSTRACT TRUNCATED AT 250 WORDS)     

Variable rate infusion of alfentanil as a supplement to nitrous oxide anesthesia for general surgery

In this study we attempted to define the minimal dosage of alfentanil (AF) needed in combination with nitrous oxide to provide satisfactory anesthetic conditions for lower abdominal gynecologic surgery. General anesthesia was induced in 12 women with AF (150 micrograms X kg-1) and 66% N2O in O2. An infusion of AF was started immediately after the AF induction dose and was varied between 25-150 micrograms X kg-1 X hr-1 as indicated by the patient's responses to stimulation during operations lasting 208 +/- 22 (SEM) min. Small bolus doses of AF (7 micrograms X kg-1) were administered to rapidly suppress precisely defined somatic, hemodynamic, and other sympathetic responses to stimulation. With one exception, all responses in all patients were controlled rapidly by increments of AF. The mean dosages of AF needed during different stages of surgery are reported. The AF infusion was stopped 16.2 +/- 1.2 min before discontinuing N2O. Recovery of consciousness along with satisfactory spontaneous ventilation occurred promptly after completion of the operation (4.0 +/- 0.5 min after N2O; 20.3 +/- 1.4 min after stopping AF infusion). This study demonstrates the feasibility of maintaining general anesthesia with N2O and a continuous AF infusion at a rate varied according to the patient's responses and allowing for prompt recovery of consciousness and satisfactory spontaneous ventilation at the conclusion of operations lasting as long as 5 hr.     

Preinduction atropine or glycopyrrolate and hemodynamic changes associated with induction and maintenance of anesthesia with propofol and alfentanil

Total intravenous anesthesia by infusions of propofol and alfentanil may be associated with decreases in heart rate and blood pressure. The effects of two vagolytic agents on these hemodynamic changes were studied in 24 ASA physical status 1 patients undergoing body surface surgery. Patients were randomly allocated to receive atropine 10 micrograms/kg, glycopyrrolate, 5 micrograms/kg, or 0.9% sodium chloride, intravenously, 5 min before induction of anesthesia with loading doses of alfentanil, 50 micrograms/kg and propofol 1 mg/kg. Anesthesia was maintained with infusions of alfentanil 50 micrograms.kg-1.hr-1, and propofol 10 mg.kg-1.hr-1 for the first 10 min, 8 mg.kg-1.hr-1 for the next 10 min, and 6 mg.kg-1.hr-1 thereafter. Patients given glycopyrrolate before anesthesia had significantly higher arterial pressures than did patients receiving either atropine or saline, even though heart rates increased equally after glycopyrrolate and atropine.     

Haemodynamic effects of induction of general anaesthesia with propofol during epidural anaesthesia

PURPOSE: To clarify whether propofol administration during thoracic or lumbar epidural anaesthesia intensifies the haemodynamic depression associated with epidural anaesthesia. METHODS: Patients (n = 45) undergoing procedures of similar magnitude were randomly divided into three study groups: a control group (n = 15) receiving general anaesthesia alone and two study groups undergoing thoracic (n = 15) and lumbar epidural anaesthesia (n = 15) before induction of general anaesthesia. All patients received 2 mg.kg-1 propofol at a rate of 200 mg.min-1, followed by a continuous infusion of 4 mg.kg-1.hr-1. Mean arterial blood pressure (MAP) and heart rate (HR) were measured at baseline, three minutes after induction, and one minute after tracheal intubation in all three groups and at 20 min after epidural anaesthesia was established in the thoracic and lumbar groups. RESULTS: Following epidural anaesthesia, MAP decreased from 94 +/- 14 (SD) at baseline to 75 +/- 11 mmHg (P < 0.0001) in the thoracic group and from 92 +/- 12 to 83 +/- 15 mmHg in the lumbar group. After propofol administration, MAP decreased further in the thoracic group to 63 +/- 9 mmHg (P = 0.0077) and to 67 +/- 10 mmHg (P = 0.0076) in the lumbar group. The MAP following propofol induction in the thoracic group (P < 0.0001) and in the lumbar group (P = 0.0001) was lower than MAP in the control group (81 +/- 9 mmHg). HR decreased only in response to thoracic epidural anaesthesia (P = 0.0066). CONCLUSION: The hypotensive effects of propofol are additive to those of epidural anaesthesia, resulting in a profound decrease in mean arterial pressure.     

Sudden increase in bispectral index during propofol anesthesia in three patients

We report 3 patients who developed a sudden unpredicted increase in bispectral index (BIS) value during propofol and fentanyl anesthesia. The patients were induced with propofol 2-mg.kg-1 and fentanyl 2-micrograms.kg-1 and muscle relaxation was obtained by vecuronium 0.12-mg.kg-1. During induction of anesthesia, BIS value went down to below 50 in all three cases, and anesthesia was maintained by continuous infusion of propofol at a rate of 5 mg.kg-1.hr-1 and intermittent administration of fentanyl. Forty to sixty min after starting the operation, BIS value increased suddenly (up to 80) and the body movement of the patients was observed. The serum concentration of propofol was approximately 2.5 micrograms.ml-1. All patients were successfully treated with increasing the infusion rate of propofol and additional administration of fentanyl. No clear recall or explicit memory during operation was observed after anesthesia, but, anesthesiologists might have to pay more attention to unpredictable changes of anesthetic depth during propofol anesthesia using target controlled infusion.     

Prophylactic nitroglycerin infusions during coronary artery bypass surgery

The effects of prophylactic infusion of 1 microgram X kg-1 X min-1 nitroglycerin (NTG) on the incidence of ischemia, hypertension, hypotension and perioperative myocardial infarction were studied in 81 patients during coronary artery bypass grafting (CABG). Forty-one patients (Group 1) received NTG and 40 patients (Group 2) received placebo. All patients received fentanyl for anesthesia and pancuronium. Mean arterial pressure (MAP), pulmonary capillary wedge pressure (PCWP), heart rate (HR), and cardiac output (CO) were measured before and after induction of anesthesia, after intubation, before and after chest incision, after sternotomy, after the pericardium was opened, and during normothermic cardiopulmonary bypass. Myocardial ischemia and infarction were diagnosed from the ECG, hypertension was defined as a 20% increase in MAP, and hypotension was defined as a 20% decrease in MAP compared with preinduction values. No significant differences between Groups 1 and 2 in HR, PCWP, or CO were seen. MAP was significantly lower in Group 1 than Group 2 (P less than 0.05) before chest incision, but increased to levels equal to Group 2 after sternotomy. Hypertension occurred in 32 Group 2 patients and 25 Group 1 patients (0.05 less than P less than 0.1). Group 1 patients had 0.95 +/- 0.14 episodes per patient of hypertension, while Group 2 patients had 2.10 +/- 0.31 episodes (P less than 0.05). Hypotension occurred in 20 Group 1 patients but only six Group 2 patients (P less than 0.05). There was no difference in the incidence of ischemia. In Group 1, nine patients (22%) had ECG changes of ischemia, while 12 patients in Group 2 (30%) had ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)     

Atracurium infusion in total intravenous anesthesia

The neuromuscular blocking effect of atracurium given as a bolus dose (0.5 mg X kg-1) followed by a maintenance infusion was studied during two different anesthetic techniques. It has been reported that benzodiazepines interact with non-depolarising neuromuscular blockers. In this study no difference was found in the effect of atracurium given with conventional fentanyl/nitrous oxide anesthesia when compared to total intravenous anesthesia using midazolam/alfentanil. More than 90% twitch depression was achieved after 123 and 137 s, respectively. Recovery time to 10% twitch height following the bolus dose was around 32 min. The dosage range for atracurium given by infusion (0.29-0.44 mg X kg-1 X h-1) was confirmed.     

Comparison of fentanyl, sufentanil, and alfentanil anesthesia in patients undergoing valvular heart surgery

The hemodynamic responses to anesthesia and surgery were studied in three groups of 20 patients undergoing valve replacement surgery. Anesthesia was induced with either fentanyl (75 micrograms/kg), sufentanil (15 micrograms/kg), or alfentanil (125 micrograms/kg). Pancuronium (8 mg) was given for muscle relaxation and the lungs were ventilated with oxygen/air (FIO2 = 0.5). Additional fentanyl (25 micrograms/kg) or sufentanil (5 micrograms/kg) was given before skin incision. Patients receiving alfentanil were given a continuous infusion at a rate of 0.5 mg X kg-1 X hr-1. Only mean arterial blood pressure (MABP) and systemic vascular resistance (SVR) changed significantly in response to anesthesia or surgery. MABP decreased on average 24.5 mm Hg (P less than 0.01) after induction of anesthesia with sufentanil in patients with mitral valve disease. MABP and SVR increased significantly (P less than 0.01) in patients with aortic valve disease receiving fentanyl. There were no other statistically significant changes within the groups. Four patients (two in the sufentanil group and one from each of the other groups) developed transient hypotension during induction of anesthesia. It is concluded that all three opioids can provide satisfactory anesthesia for patients having valve replacement surgery.     

肺叶切除术患者不同通气模式下每搏量变异度的变化

目的 探讨肺叶切除术患者不同通气模式下每搏量变异度(SW)的变化.方法 择期行肺叶切除术患者44例,年龄44～64岁,体重47～86 kg,ASA分级Ⅰ或Ⅱ级.采用FloTrac压力换能器及Vigileo心输出量监测仪持续监测CI、每搏量指数(SVI)和SVV.术中补液速率6～8 ml·kg-1·h-1(晶胶比1∶1)维持血容量.于仰卧位双肺通气5 min(T1)、侧卧位双肺通气2 min(T2)、单肺通气开胸前(T3)、单肺通气开胸后5 min(T4)、30 min(T5)、单肺通气+PEEP5 cm H2O 1 min(T6)、15 min(T7)、肺复张前(T8)、肺复张即刻(T9)和肺复张后1 min(T10)时记录SVV、CI和SVI.SVV＜ 13％为正常值.结果 患者术中血液动力学平稳,CI和SⅥ均在正常范围内波动.T9时SVV＞13％,其余各时间点均＜13％.SVV T2,3之间差异无统计学意义,T5～7之间差异均无统计学意义(P＞0.05);T9时SVV较T8.10时升高(P＜0.01).结论 肺叶切除术中,单肺通气以及单肺通气联合PEEP 5 cm H2O时SVV可用于指导液体治疗的判断,而在肺复张时SVV不能指导液体治疗.     

Clinical experience with adenosine for controlled hypotension during cerebral aneurysm surgery

The cardiovascular effects of adenosine-induced hypotension were studied in 47 patients undergoing intracranial vascular surgery under neurolept anesthesia. Adenosine infusion (214 +/- 18 micrograms X kg-1 X min-1) decreased mean arterial pressure (MAP) by 42 +/- 1% from 80 +/- 1 to 46 +/- 1 mm Hg for an average of 29 +/- 5 min of hypotension. Hypotension was associated with a minor increase in heart rate (13 +/- 2%) and with prolongation of the PR interval (9 +/- 2%). ST-T depression did not occur except in one patient with a previous history of myocardial infarction. The adenosine-induced increase in cardiac index (42 +/- 9%, n = 7) was associated with a 63 +/- 10% decrease in systemic vascular resistance index (n = 7) while the pulmonary capillary wedge pressure remained unchanged. Adenosine metabolism was limited and there was no accumulation of the end metabolite, uric acid. Serum creatinine levels were normal in all patients postoperatively. We conclude that adenosine rapidly induces a stable and easily controlled hypotension in man without tachyphylaxis or rebound hypertension. There were no signs of renal or myocardial dysfunction except for dysrhythmias that occurred in two patients with a history of myocardial infarction.     

Intraoperative control of mean arterial pressure and heart rate with alfentanyl with fuzzy logic

OBJECTIVES: To describe a fuzzy logic controller that adjust alfentanil infusion during surgery based on changes in mean arterial pressure (MAP) and heart rate (HR). MATERIAL AND METHODS: We designed a fuzzy logic controller using if ... then ... conditions written in C language, to be executed by a 486 PC with a 66 Mhz CPU. The controller was used with eight ASA I-II patients undergoing gynecological surgery under anesthesia with propofol, alfentanil and ventilated with oxygen/air. MAP and HR were input every three minutes, after which the controller generated an infusion based on those figures. We performed a statistical study of alfentanil consumption time until extubation and time of hemodynamic stability. Relative error of MAP was calculated. RESULTS: The controller was used for a total of 373 min with the eight patients. MAP was 15% below the desired level for 2.14% (18 min) of that time and was 15% over the desired level for 5.6% (21 min) of the time. MAP held steady within the range of stability for the remaining 92.26% (334 min) of the time the controller was used. The relative error of MAP was 7.8 +/- 1.5%. Mean time until extubation was 7 min and 2 s. CONCLUSIONS: We believe the controller can be used to automate taks executed by experts. The controller was useful for stabilizing HR and MAP.     

艾司洛尔对患者麻醉诱导气管插管时脑电双频谱指数的影响

Objective To evaluate the effect of esmolol on bispectral index (BIS) in patients undergoing orotracheal intubation during induction of anesthesia and to investigate the mechanism of inhibiting the cardiovascular responses to tracheal intubation.Methode Forty patients in physical status of ASA Ⅰ or Ⅱ and aged 20-60 years were randomly divided into 2 groups ( n = 20 each): esmolol group (group E) and control group (group C). Anesthesia was induced with midazolam 0.1 mg/kg, fentanyl 5 μg/kg and vecuronium 0.1 mg/kg. In group E, esmolol 1 mg/kg was given intravenously before anesthesia induction and followed by an infusion of esmolol 250 μg· kg- 1·min-1, while a comparable volume of saline was given for group C. Mean arterial pressure (MAP), heart rate (HR) and BIS were recorded before esmolol administration, before induction of anesthesia, before orotracheal intubation, and at 1, 2 and 5 min after intubation, respectively.Results There were no significant differences in HR, MAP and BIS between the two groups before tracheal intubation. HR and MAP significantly increased after tracheal intubation in both groups, but BIS only in group C significantly increased after intubation.HR, MAP and BIS were significantly lower after intubation in group E than in group C ( P＜ 0.05).Conclusion Esmolol can decrease BIS during tracheal intubation and its antinociceptive property is related to the mechanism of inhibiting cardiovascular responses to tracheal intubation.     

鼓室成形术病人面神经诱发肌电位反应与神经肌肉阻滞程度间的相关性

目的 探讨面神经诱发肌电位(EEMG)反应与神经肌肉阻滞(NMB)程度间的相关性.方法 拟行鼓室成形术病人40例,分为面神经暴露组(A组,n=16)和面神经非暴露组(B组,n=24),术中同步行面神经EEMG监测和外周NMB程度监测.不同NMB程度(0、25%、50%、75%、100%)时测定面神经EEMG刺激阈值和固定刺激强度下EEMG振幅.EEMG的刺激阈值和振幅与NMB程度间进行等级相关分析.结果 NMB≥75%时,4例病人未能诱发EEMG;A组和B组EEMG刺激阈值与NMB程度间的相关系数分别为0.38和0.26(P＜0.01),EEMG振幅与NMB程度间的相关系数分别为-0.66和-0.55(P＜0.01).在各个NMB水平,A组EEMG刺激阈值低于B组(P＜0.01);随着NMB程度的加深,EEMG刺激阈值逐渐增加,EEMG振幅逐渐降低(P＜0.05).结论 鼓室成形术病人面神经EEMG刺激阈值与NMB程度呈正相关,EEMG振幅与NMB程度呈负相关.