Intrathecal picrotoxin minimally alters electro-encephalographic responses to noxious stimulation during halothane and isoflurane anesthesia.
Intrathecal picrotoxin minimally alters electro-encephalographic responses to noxious stimulation during halothane and isoflurane anesthesia.
复制标题
鞘内印防己毒素对氟烷和异氟烷麻醉过程中有害刺激的脑电图反应影响最小。
DOI：
10.1111/j.1399-6576.2005.00695.x
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
Antognini,JF
中科院分区：
文献类型：
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作者：
Dominguez,CL;Barter,LS;Antognini,JF
背景：异氟醚和氟烷在脊髓中起作用，使伤害性刺激引起的冲动向大脑的上行传递变钝。由于鞘内印防己毒素（γ-氨基丁酸-A受体的拮抗剂）部分逆转了异氟烷和氟烷的固定作用，我们假设，脑电反应的伤害性stimulation.Methods：大鼠麻醉异氟烷（n = 8）或氟烷（n = 8）和椎板切除术进行了部分逆转。 在确定最小肺泡浓度（MAC）之后，在分别施加后爪钳、尾钳和在0.8和1.2MAC下对尾部施加电流期间记录脑电图（EEG）。结果：氟烷麻醉时脑电图较异氟烷更活跃（95%功率下边缘频率为25.6 ± 2.1Hz比23.1 ± 1.6Hz，P<0.05）。 脑电活动常发生高频变化（如0.8MAC氟烷组，50%功率下的边缘频率中位数为7.6 ± 3.1Hz ~ 10.7 ± 2.6Hz，P<0.05）。 印防己毒素最低限度地影响了这一response.Conclusions：nocolate刺激引起的EEG反应，是最低限度地改变鞘内印防己毒素。这表明异氟烷和氟烷在脊髓中不具有间接抑制EEG反应的GABA能作用。
Background:Isoflurane and halothane act in the spinal cord to blunt ascending transmission of impulses to the brain resulting from noxious stimulation. Because intrathecal picrotoxin (an antagonist at the gamma‐aminobutyric acid‐A receptor) partially reverses the immobilizing effect of isoflurane and halothane, we hypothesized that the electroencephalographic response to noxious stimulation would likewise be partially reversed by intrathecal picrotoxin.Methods:Rats were anesthetized with isoflurane (n = 8) or halothane (n = 8) and a laminectomy performed. Following determination of minimum alveolar concentration (MAC), the electroencephalogram (EEG) was recorded during separate applications of a hindpaw clamp, tail clamp and electrical current to the tail at 0.8 and 1.2 MAC. Picrotoxin was then applied to the exposed spinal cord and the EEG response to noxious stimulation again determined.Results:The EEG was more active during halothane anesthesia than isoflurane (spectral edge frequency for 95% power: 25.6 ± 2.1 Hz vs. 23.1 ± 1.6 Hz,P< 0.05). Noxious stimulation usually caused the EEG to shift to higher frequencies (e.g. for 0.8 MAC halothane, median edge frequency for 50% power: from 7.6 ± 3.1 Hz to 10.7 ± 2.6 Hz,P< 0.05). Picrotoxin minimally affected this response.Conclusions:Noxious stimulation evokes an EEG response that is minimally altered by intrathecal picrotoxin. This suggests that isoflurane and halothane do not have GABAergic actions in the spinal cord that indirectly suppress the EEG response.