氧化亚氮对安氟醚脑电功率谱的影响

２０例择期手术患者，随机分成安氟醚（Ｅｎｆ）组和安氟醚加氧化亚氮（Ｅｎｆ／Ｎ２Ｏ）组，每组１０例。静脉硫喷妥钠５ｍｇ／ｋｇ、阿曲库铵０．６￣０．７ｍｇ／ｋｇ诱导后气管内插管，机械通气维持ＰｅｔＣＯ２４．２７￣４．９３ｋＰａ。间断静脉注射阿曲库铵１０￣１５ｍｇ，维持Ｔ４／Ｔ３〈２５％，ＳｐＯ２≥９９％，采用ＦＰ１－Ａ１、ＦＰ２－Ａ２双导联脑电监测，记录原始脑电以观察脑电功率谱和９５％边缘频率（ＳＥＦ     

安氟醚及异氟醚对阿曲库铵临床药效的影响

目的：观察吸入１％安氟醚或等效浓度异氟醚对阿曲库铵临床药效的影响。方法：３０例择期手术病人随机分为三组，分别吸入６７％Ｎ２Ｏ（Ⅰ组），１％安氟醚（Ⅱ组）或０．６７％异氟醚（Ⅲ组）后观察阿曲库铵临床药效。结果：静注阿曲库铵０．５ｍｇ／ｋｇ后，Ⅰ、Ⅱ和Ⅲ组的起效时间分别是２．２±０．４２分、２．１±０．４２分和２．１±０．３４分（Ｐ＞０．０５），作用时间分别是４５．８５±３．７分、５５．２５±６．４７分和５５．８８±８．２５分（Ｐ＜０．０１）；维持９０％～９５％颤搐抑制所需阿曲库铵的静脉滴注速度分别为６．２７７±１．０９２μｇ·ｋｇ－１·ｍｉｎ－１、４．２７２±０．５８５μｇ·ｋｇ－１·ｍｉｎ－１和４．５０５±０．７１６μｇ·ｋｇ－１·ｍｉｎ－１（Ｐ＜０．０１）。结论：１％安氟醚及等效浓度的异氟醚均可增强阿曲库铵的临床药效，但两者之间的增强无显著差异。     

相同MAC浓度的安氟醚和异氟醚对脑电图功率谱的影响

２４例 ２０～５０岁、ＡＳＡⅠ级、行择期外科手术的患者，随机分成两组：安氟醚组和异氟醚组。不用术前药，麻醉诱导以静脉硫喷妥钠５ｍｇ／ｋｇ、阿曲库胺０．６～０．７ｍｇ／ｋｇ。单纯吸入安氟醚或异氟醚维持全麻。气管插管后控制呼吸，维持呼气末二氧化碳分压（ＰＥＴＣＯ２）４．２７。４．９３ｈｐａ。以ＴＯＦ监测肌松，间断给予阿曲库胺 １０～１５ｍｇ，维持Ｔ４／Ｔ１＜２５％。采用 ＦＰ１－Ａ１、ＦＰ２－Ａ２双导联监护脑电，验证呼气末麻醉药浓度在 ０． ５、０．８、１． ０、１． ３和 １．５ ＭＡＣ时的脑电功率谱、９５％边缘频率（ＳＥＦ）和中心频率（ＭＰＦ）改变。结果发现，随ＭＡＣ增加脑电功率谱表现出波增加，α和β波减少，而ＳＥＦ、ＭＰＦ值随ＭＡＣ增加而减少的改变呈负性线性关系，ｒ＝－０．９５。提示脑电功率谱、ＳＥＦ和ＭＰＦ在评价全麻深度上有一定意义。     

异氟醚对眼部血液动力学的影响

目的 研究异氟醚对眼部血液动力学的影响。方法 选择无明显眼部疾病的成年非头颈手术患者１５例,静脉注射异丙酚、阿曲库铵快速诱导麻醉,插入喉罩,吸入异氟醚维持麻醉,采用彩色多普勒成像仪（ＣＤＩ）预测麻醉前、异氟醚１ＭＡＣ和１．５ＭＡＣ３０ｍｉｎ后的双眼动脉（ＯＡ）、视网膜中央动脉（ＣＲＡ）和睫状后动脉（ＰＣＡ）的收缩期峰流速（ＰＳＶ）、舒张期末流速（ＥＤＶ）、平均流速（Ｔｍａｘ）和阻力指数（ＲＩ）及血     

不同麻醉深度下中枢神经系统的功能状态(数量化脑电图和麻醉深度的关系)

目的：探讨数量化脑电图与七氟醚麻醉深度的关系。方法：６２例腹部手术病人，常规麻醉诱导、气管内插管。机械通气，潘库溴铵或阿曲库铵维持肌松。手术探查毕，调整每个病人的七氟醚呼气末浓度依次达２％→１．５％→１％，每种浓度维持至少１５分钟，记录３分钟数量化ＥＥＧ及ＭＡＰ、ＨＲ变化。结果：随七氟醚呼气末浓度降低，原始脑电波逐渐由低频高振幅波转变为高频低振幅波；ＳＥＦ和ＭＦ趋势曲线明显右移；ＳＥＦ、ＭＦ、ＢＩＳ、δＲ明显差异（Ｐ＜０．０１）。血流动力学的变化仅在七氟醚呼气末浓度１％与２％时有明显差异（Ｐ＜０．０１）。结论：数量化脑电图能监测不同七氟醚麻醉深度时大脑皮层电活动变化，而ＭＡＰ和ＨＲ只能区别极深和极浅的麻醉状态。     

地氟醚、七氟醚和异氟醚对犬冠脉血流的影响

目的：采用超声血流量监测仪观察地氟醚、七氟醚和异氟醚对犬冠脉血流的影响。方法：犬１８只，腹腔注射１．５％硫喷妥钠２０ｍｇ／ｋｇ，静脉注射阿曲库铵０．８ｍｇ／ｋｇ麻醉诱导，气管插管后取正中开胸，分离冠状动脉左前降支，将３ｍｍ或３．５ｍｍ超声Ｄｏｐｐｌｅｒ血管探头置于分离血管处，连接超声多普勒冠脉血流量监测仪测定冠脉血流量，然后随机吸入地氟醚、七氟醚或异氟醚，ＭＡＣ分别为７．２％、２．３％和１．２８％     

顺式阿曲库铵肌松效应的临床观察

目的;观察顺式阿曲库铵的肌松效应,并与阿曲库铵相比,以了解该药在国人的作用特点。方法：ＡＳＡⅠ－Ⅱ级择期手术病人３０例,随机分为三组,每组１０例,分别予顺式阿曲库铵０．１ｍｇ／ｋｇ,０．１５ｍｇ／ｋｇ和阿曲库铵０．５ｍｇ／ｋｇ,诱导麻醉,观察心率、血压和全身皮肤情况以及ＴＯＦ的变化。结果：顺式阿曲库铵０．１ｍｇ／ｋｇ、０．１５ｍｇ／ｋｇ与阿曲库铵０．５ｍｇ／ｋｇ均未引起心率、血压明显变化与皮肤潮红     

普鲁卡因静脉复合麻醉对左心功能的影响

作者曾对异氟酸和芬太尼对左心功能影响进行研究，发现大剂量芬太尼（４０μｇ／ｋｇ）抑制作用大于异氟醚。本文对普普卡因静脉复合麻醉对左心功能的影响进行研究，并与异氟醚吸入麻醉对照比较。资料与方法健康杂种犬旧只，体重１２．９±１．９ｋｇ。随机分为二组：对照组为异氟醚吸入麻醉（简称１组），犬８只，吸入１．５～１．６％（１．２ＭＡＣ）异氟醚。实验组为普鲁卡因静脉复合麻醉（简称Ｐ组），大１０只，静滴２％普鲁卡因复合液（１０％葡萄糖２００ｍｌ，１０％普鲁卡因５０ｍｌ，芬太尼０．２ｍｇ和琥珀胆碱２００ｍｇ），按…     

安氟醚、异氟醚对眼压的影响

安氟醚和异氟醚是目前广泛使用的吸入麻醉药。本文观察其对眼压的作用。资料与方法一般资料　３０例择期行胆囊切除术的成年患者,术前无心、肺、肝、肾功能异常,亦无高血压病史,平均年龄３６±７－９岁,体重５３－２±５－２ｋｇ,随机分为安氟醚组和异氟醚组,每组１５例。麻醉与监测　所有患者进入手术室后,静卧１０分钟,用０－３％丁卡因滴眼后测眼压作为对照组。麻醉诱导采用静注安定０－２ｍｇ／ｋｇ、芬太尼１－５μｇ／ｋｇ、利多卡因１－５μｇ／ｋｇ、２－５％硫喷妥钠５ｍｇ／ｋｇ、阿曲库铵０－３～０－５ｍｇ／ｋｇ、注药…     

异氟醚一氧化亚氮和硫喷妥钠麻醉在术中体感诱发电位的监护

研究了５１例志愿全麻手术患者不同麻醉药浓度异氟醚和６６％氧化亚氮及硫喷妥钠（７ｍ／ｋｇ）时对体感诱发电位（ＳＥＰ）的影响。结果表明，随着异氟醚吸入浓度的增高，ＳＥＰ各个波峰潜伏期（Ｐ１、Ｎ１、Ｐ２、Ｎ２）逐渐延长，波幅（Ｐ１－Ｎ１、Ｐ２－Ｎ２）逐渐降低，其中以Ｎ２潜伏期延长最明显（Ｐ＜０．０１），Ｐ２－Ｎ２波幅降低最显著。停止吸入麻醉药后，ＳＥＰ各个波峰潜伏期均开始缩短，波幅逐渐增加；出现角膜反射时，Ｎ２潜伏期已达麻醉前范围（Ｐ＞０．０５）。再次加深麻醉后，ＳＥＰ潜伏期和波幅重现以上变化。提示异氟醚一氧化亚氮麻醉使ＳＥＰ呈剂量依赖效应，麻醉深浅与ＳＥＰ变化呈正相关关系。另外，硫喷妥钠静注１０分钟后，ＳＥＰ潜伏期延长，波幅下降，仍以Ｎ２潜伏期延长和Ｐ２－Ｎ２波幅降低最显著。说明异氟醚一氧化亚氮和硫喷妥钠麻醉中，皮层ＳＥＰ可做为连续监护麻醉深浅的有效方法，而晚成份（Ｎ２潜伏期和Ｐ２－Ｎ２波幅）为麻醉深度的重要指标。     

The effects of isoflurane and isoflurane-nitrous oxide anesthesia on brainstem auditory evoked potentials in humans

Monitoring of brainstem auditory evoked potentials (BAEP) during neurological surgery can provide useful information. However, in order to interpret intraoperative BAEP changes, it is necessary to delineate the influence of anesthesia, including inhalation agents. In this study, we examined the influence of isoflurane and isoflurane-nitrous oxide anesthesia on BAEP in ten healthy volunteers during normothermic, normocapnic, and normotensive conditions. Isoflurane significantly increased the latencies of peaks III, IV, and V at all end-tidal concentrations studied (1.0%, 1.5%, and 2.0%). Addition of 50% nitrous oxide did not influence these findings. The increase in latencies with isoflurane anesthesia, however, was nonlinear and appeared to plateau after 1.5%. We suggest that during isoflurane anesthesia, an intraoperative increase in peak V latency beyond 1.0 msec is best explained by factors other than direct effects of isoflurane.     

Auditory evoked potentials during isoflurane anaesthesia

Brainstem auditory evoked potentials (BAEP) were determined in 12 volunteers. The effect of isoflurane anaesthesia on BAEP was determined in six patients. Body temperature and end-tidal CO2% were controlled. Increasing end-tidal isoflurane concentration from 0.6-2.4% increased BAEP wave I, III and V latencies. The amplitude of wave V decreased with increasing isoflurane concentration. Thus a dose-related change was demonstrated between end-tidal concentration of isoflurane and BAEP latencies.     

Plasma concentrations of laudanosine, but not of atracurium, are increased during the anhepatic phase of orthotopic liver transplantation in pigs

To quantify the changes in plasma concentrations of atracurium and laudanosine induced by the lack of hepatic function and circulation, the authors studied nine domestic pigs (22-25 kg) undergoing an orthotopic liver transplantation, and three control animals without surgery, using atracurium as the muscle relaxant. After intubation facilitated by isoflurane 2-3%, anesthesia was maintained with isoflurane (0.5% in oxygen) and fentanyl (4 micrograms.kg-1.hr-1). Ventilation was controlled to keep end-tidal CO2 at 35-40 mmHg, body temperature maintained at 35.5-37.5 degrees C, and arterial pH at 7.35-7.50. The right sciatic nerve was stimulated with a nerve stimulator delivering a single twitch at 0.1 Hz with 0.2-ms duration, at supramaximal stimulation. The force of the corresponding evoked isometric muscle contraction was continuously measured by a force-displacement transducer. A single iv bolus of atracurium (2 mg/kg) was given to obtain a 90-95% twitch depression, followed 5 min later by a constant-rate iv infusion of atracurium at 120 micrograms.kg-1.min-1 maintained during the entire investigation. Blood samples for plasma atracurium and laudanosine concentrations were drawn every 15 min. In the control group, plasma concentrations of atracurium remained stable between 6.5-8.0 micrograms/ml following initial bolus injection; plasma concentrations of laudanosine increased during the first 60 min, then remained stable between 0.69-0.74 micrograms/ml up to the end of the study. In animals undergoing transplantation, plasma concentrations of atracurium remained stable between 10-12 micrograms/ml, despite a 90-min duration of liver exclusion.(ABSTRACT TRUNCATED AT 250 WORDS)     

Clinical evaluation of atracurium besylate in patients at risk: major burns

Atracurium besylate 0.5 mg/kg-1, an intermediate-duration non-depolarizing neuromuscular relaxant, was administered slowly (over 75 sec) in anesthesia induction of 61 patients with major thermal injury undergoing surgical excision and immediate skin-grafting procedures. Patients' mean +/- SD age was 40 +/- 9, body weight 64 +/- 2, burn size ranging from 20% to 90% of body surface area (BSA), postburn day of surgery 5th and more. Induction of anesthesia was carried out with sodium thiopental 2-5 mg/kg-1 plus fentanyl 2.8 micrograms/kg-1 e.v. and after few minutes atracurium 0.5 mg/kg-1 e.v. Anesthesia was maintained with N2O/O2 (70%/30%), isoflurane and small amounts of fentanyl. The mean arterial pressure and heart rate were recorded at I, II, III, IV, V min post atracurium administration. The endotracheal intubation conditions were assessed by a "IOT score". Results are expressed as mean value +/- standard deviation. The significance of the difference in mean values was analysed by t-test. Little haemodynamic changes occurred; intubating conditions showed a relative hyposensitivity of burn patients to atracurium, more severely burned patients (greater than 50-60%) exhibiting greater resistance.     

Differential effects of isoflurane on human median nerve somatosensory evoked potentials

The effect of isoflurane on median nerve somatosensory evoked potentials (MN-SSEPs) was studied in 15 patients. Anesthesia was induced with thiamylal and maintained with oxygen and isoflurane. MN-SSEPs were recorded in awake patients and after achieving 0.5, 1.0, 1.5, and 2.0% stable end-tidal concentrations of isoflurane. Peak latencies and amplitudes of EP, N13, and N20 and conduction times EP-N13, N13-N20, and EP-N20 were measured. Peak latencies of all components increased after all concentrations of isoflurane compared with control values. N20 peak latencies after 1% and 1.5% isoflurane differed significantly, whereas EP and N13 latencies showed no significant difference. No significant change in conduction time EP-N13 resulted from 1% and 1.5% concentrations of isoflurane compared with control values. Isoflurane increased conduction time N13-N20 significantly when compared with control values, and this increase was dose related. Amplitude of EP and N13 did not show significant change with 1% and 1.5% isoflurane when compared with control values. Amplitude of N20 decreased significantly following isoflurane anesthesia compared with control values, and the difference between 1% and 1.5% isoflurane recordings was also statistically significant. N20 was not discernible in one out of 14 patients after 1.5% and in three out of ten patients after 2% isoflurane. These results indicate that subcortical potentials are less affected by isoflurane anesthesia than cortical potentials. Amplitude reduction of cortical potentials was more noticeable than either prolongation of peak latency or conduction time.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of high-dose fentanyl anesthesia on auditory brain stem responses]

It was previously reported that high-dose (50 micrograms.kg-1) fentanyl anesthesia had no effect on auditory brainstem response (ABR). However, the effect of the dose of 100 micrograms.kg-1 of fentanyl is unknown. We examined the effects of the dose of 50 micrograms.kg-1 and 100 micrograms.kg-1 of fentanyl on ABRs in 10 patients scheduled for cardiovascular surgery. No significant change was observed immediately after infusion of 50 micrograms.kg-1 of fentanyl, but peak latencies of waves I, III and V were significantly prolonged and the amplitude of wave V was significantly decreased immediately after infusion of 100 micrograms.kg-1 of fentanyl. The interpeak latencies of I-III and I-V were not affected. Therefore, prolongations of latencies of waves III and V were due to the change of latency of wave I. These results demonstrate that high-dose (100 micrograms.kg-1) fentanyl anesthesia depresses the peripheral auditory perception but dose not depress the central conduction.     

异丙酚和异氟醚对全麻手术病人脑干听觉诱发电位影响的比较

目的 比较异丙酚和异氟醚对全麻手术病人脑干听觉诱发电位(BAEP)的影响.方法 择期拟行全麻手术的病人30例,年龄20～50岁,体重44～75 kg,ASA分级Ⅰ或Ⅱ级,随机分为2组(n=15):异丙酚组(P组)和异氟醚组(I组).监测SpO2、PETCO2、BAEP和BIS.麻醉诱导:P组靶控输注异丙酚,血浆靶浓度6μg/kg,I组吸入3%异氟醚,两组静脉注射维库溴铵0.1 mg/kg,气管插管后行机械通气,维持PETCO235～40 mm Hg,SpO298%～100%.P组靶控输注异丙酚,I组吸入异氟醚维持麻醉.分别于麻醉诱导前(T0)、气管插管后BIS达70并维持5 min(T1)和BIS达50并维持5 min(T2)时,记录Ⅰ波、Ⅲ波、Ⅴ波的潜伏期、Ⅰ-Ⅲ、Ⅲ-Ⅴ、Ⅰ-Ⅴ的峰间期.结果 P组Ⅰ波、Ⅲ波、Ⅴ波的潜伏期和Ⅰ-Ⅲ、Ⅲ-Ⅴ、Ⅰ-Ⅴ的峰间期组内比较差异无统计学意义(P＞0.05);与T0时比较,I组T1时Ⅰ波、Ⅲ波、Ⅴ波的潜伏期和Ⅰ-Ⅲ、Ⅲ-Ⅴ、Ⅰ-Ⅴ的峰间期差异无统计学意义(P＞0.05),T2时Ⅲ波、Ⅴ波的潜伏期和Ⅰ-Ⅲ、Ⅲ-Ⅴ、Ⅰ-Ⅴ的峰间期延长(P＜0.05或0.01);与T1时比较,I组T2时Ⅲ波、Ⅴ波的潜伏期和Ⅰ-Ⅲ、Ⅰ-Ⅴ的峰间期延长(P＜0.05或0.01);与P组比较,I组T2时Ⅴ波潜伏期和Ⅰ-Ⅴ峰间期延长(P＜0.05).结论 与异氟醚相比,等效剂量的异丙酚对全麻手术病人BAEP的影响更小,提示其对脑干功能的抑制作用更小.

Abstract：

Objective To compare the effects of propofol versus isoflurane on brainstem auditory evoked potential (BAEP) and explore the difference in the effects of the two anesthetics on the brainstem. Methods Thirty ASA Ⅰ or Ⅱ patients aged 20-50 yr without heating disorder, scheduled for elective surgery performed under general anesthesia were randomly divided into 2 groups (n = 15 each): propofol group (group P) and isoflurane group (group Ⅰ). SpO2, PET CO2, BIS and BAEP were continuously monitored before and during anesthesia. Anesthesia was induced by propofol administered by TCI or isoflurane inhalation. Tracheal intubation was facilitated with vecuronium. The patients were mechanically ventilated. PET CO2 was maintained at 35-40 mm Hg and SpO2 at 98%-100%. After intubation BIS was maintained at 70 and 50 respectively ,the latency of the wave Ⅰ , Ⅱ and Ⅴ and the inter-peak latency (IPL) betwecn wave Ⅰ -Ⅲ , Ⅲ-Ⅴ and Ⅰ -Ⅴ were recorded.Results In group P there was no significant difference in the latency of the wave Ⅰ , Ⅲ and Ⅴ and the IPL between wave Ⅰ - Ⅲ , Ⅲ - Ⅴ and Ⅰ - Ⅴ between the baseline before anesthesia and at BIS 70 and 50. In group Ⅰ the latency of wave Ⅲ and Ⅴ and the IPL between wave Ⅰ - Ⅲ , Ⅲ - Ⅴ and Ⅰ - Ⅴ were significantly longer at BIS 50 than the baseline before anesthesia, while the latency of wave Ⅲ and Ⅴ and the IPL between wave Ⅰ -Ⅲ andⅠ -Ⅴ at BIS 50 were significantly longer than that at BIS 70. At BIS 50 the latency of wave Ⅴ and the IPL between wave Ⅰ -Ⅴ were significantly longer in group Ⅰ than in group P. Conclusion At comparable depth of anesthesia propofol exerts less depressant effects on BAEP indicating less depression of brainstem.     

Histamine-release haemodynamic changes produced by rocuronium, vecuronium, mivacurium, atracurium and tubocurarine

We have examined the effects of different benzyl-isoquinolinium and steroidal neuromuscular blocking compounds on plasma concentrations of histamine, heart rate and arterial pressure in surgical patients. A single, rapid (5-s) bolus of mivacurium 0.2 mg kg-1, atracurium 0.6 mg kg-1, tubocurarine 0.5 mg kg-1, vecuronium 0.1 mg kg-1 or rocuronium 0.6 mg kg-1 was administered to 75 patients (n = 15 in each group). Anaesthesia was induced with thiopentone 6 mg kg-1 i.v. and maintained with isoflurane and 70% nitrous oxide in oxygen. Venous blood samples were obtained before induction, 1 min after thiopentone and 1, 3 and 5 min after administration of the neuromuscular blocking drug. Mivacurium, atracurium and tubocurarine caused 370%, 234% and 252% increases in plasma histamine concentrations at 1 min, respectively. Corresponding values at 3 min were 223%, 148% and 157%, respectively. These changes were significant (P < 0.01) at 1 and 3 min. In contrast, the rocuronium and vecuronium groups had no significant changes in either plasma histamine concentrations or haemodynamic variables.      

Closed-loop infusion of atracurium with four different anesthetic techniques

A new proportional-integral-derivative (PID) controller for the automated closed-loop delivery of atracurium was tested in 32 patients. Groups of 8 patients received halothane, enflurane, isoflurane, or N2O/morphine anesthesia. After induction of anesthesia with sodium thiopental 3-5 mg.kg-1, a bolus of atracurium 0.2 mg.kg-1 was delivered by the controller; this was followed by an infusion calculated by the controller to maintain the electromyogram (EMG) at a setpoint of 90% neuromuscular blockade. The average overshoot for the controller was 10.1% and the mean steady-state error 3.0%. The mean infusion rates for atracurium to maintain 90% blockade were calculated for each anesthetic group, with the inhalation anesthetics at 1 MAC. Infusion rates for N2O/morphine, halothane 0.8%, enflurane 1.7%, and isoflurane 1.4% at 90% blockade were 5.7 +/- 0.6, 4.9 +/- 0.3, 3.5 +/- 0.3, and 4.1 +/- 0.5 micrograms.kg-1.min-1, respectively (mean +/- SE). The infusion rate for atracurium at 90% blockade under N2O/morphine anesthesia was in general agreement with published values. The other infusion rates at 90% blockade have not been reported previously, but correspond to the known potencies of these inhalation anesthetics for augmentation of neuromuscular blockade. This controller performed well in comparison to previously developed controllers, and in addition was used as a research tool for rapid estimation of infusion rates.     

Atracurium with halothane and isoflurane in pediatric anesthesia

The study was carried out to assess the effects of atracurium neuromuscular blockade in children anaesthetized with N2O:O2: halothane vs N2O:O2: isoflurane. Thirty-two ASA I-II children, age 1-13 yr, undergoing elective surgery, were divided into two groups according to age and the mode of anaesthesia induction. Anaesthesia was induced in the younger children (group 1: 1-6 yr) with nitrous oxide and inspired halothane or isoflurane in oxygen via a face mask. Intravenous thiopental (6-7 mg/kg-1) was used to induce anaesthesia in older children (group 2: 7-13 yr). Each group of patients was randomly allocated to two groups each receiving halothane (group A: n = 8) or isoflurane (group I: n = 8). Halothane 0.8% end-tidal and isoflurane 1% end-tidal as anaesthesia maintenance. A bolus dose of atracurium 0.35 mg/kg-1 was administered. Premedication consisted of oral flunitrazepam (0.04 mg/kg-1) and bellafoline (0.02 mg/kg-1). Heart rate (by electrocardiography), arterial pressure (by auscultation) were monitored. Then end-expired carbon dioxide concentration was maintained at 30-40 mmHg. Neuromuscular transmission was evaluated by response to indirect stimulation (TOF) of the ulnar nerve at the wrist via surface electrodes. Conditions for endotracheal intubation were excellent in 25 of the children, good in 6 and poor in 1. The intubation was carried out within 112 s (group 1A), 130 s (group 1 I), 112 s (group 2A) and 135 s (group 2 I) following the administration of atracurium. The maximum twitch depression was recorded in the isoflurane groups.(ABSTRACT TRUNCATED AT 250 WORDS)