Comparison of electroencephalogram activity and auditory evoked responses during isoflurane and halothane anaesthesia in the rat
Comparison of electroencephalogram activity and auditory evoked responses during isoflurane and halothane anaesthesia in the rat
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DOI：
10.1046/j.1467-2995.2003.00085.x
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发表时间：
2003-01-01
影响因子：
1.7
通讯作者：
Flecknell, PA
中科院分区：
文献类型：
--
作者：
Antunes, LM;Golledge, HD;Flecknell, PA
目的比较由听觉诱发电位(AEP)和脑电(EEG)参数计算的第二微分指数(SDI)在4种等值最小肺泡浓度(MAC)时的中值频率(MF)、频谱边缘频率(SEF)和爆发抑制率(BSR)。结果麻醉深度随氟烷麻醉深度的增加而降低(F=4.198.0 5，P=0.0 5)，而异氟醚的影响不明显。在相同的麻醉深度下，氟烷对脑电和听觉诱发电位的抑制作用显著高于异氟醚(F=5.82，p=0.036和F=5.263，p=0.045)，并且异氟醚对脑电爆发的抑制作用发生在异氟烷的深层平面，而氟烷对记录到的脑电和听觉诱发电位特征的抑制作用大于氟烷。这些发现对收集脑电记录的研究项目具有强烈的意义，并对这些参数在评估大鼠异氟醚麻醉深度方面的价值提出了更普遍的怀疑。
Objectives To compare the second differential index (SDI) calculated from the auditory evoked potential (AEP) and electroencephalogram (EEG) parameters: median frequency (MF), spectral edge frequency (SEF) and burst suppression rate (BSR) determined at four equivalent minimum alveolar concentrations (MAC) of isoflurane or halothane.Animals Twelve male Wistar rats weighing 418 g (SD +/- 18.4 g);Methods Auditory evoked potentials and EEG responses were recorded in animals implanted with electrodes at established anaesthetic concentrations. Depth of anaesthesia was assessed using the strength of the pedal withdrawal reflex (PWR), and data were analysed using repeated measures ANOVA and paired t-tests.Results The SEF tended to decrease with increasing depth of halothane anaesthesia (F = 4.198, p = 0.05), but not with isoflurane. The MF and SDI were significantly higher during halothane than with isoflurane (F = 5.82, p = 0.036 and F = 5.263, p = 0.045, respectively) at equivalent depths of anaesthesia, and EEG burst suppression occurred at deeper planes of isoflurane but not halothane anaesthesia.Conclusions The study demonstrated that EEG and AEP characteristics recorded at MAC equivalent concentrations were suppressed to a greater degree by isoflurane than by halothane. These findings have strong implications for research projects where EEG recordings are collected, and also cast more general doubts upon the value of such parameters for evaluating depth of isoflurane anaesthesia in rats.