地氟醚和七氟醚对神经外科手术患者体感诱发电位的影响

目的：比较地氟醚和七氟醚对神经外科手术术中体感诱发电位（somatosensory evoked potentials， SEP）的影响．方法选择ASA分级Ⅰ～Ⅱ级，择期脊柱畸形矫形手术术中行SEP监测的患者30例，每例应用地氟醚和七氟醚，分为地氟醚组和七氟醚组（n＝30）．术中监测脑电双频指数（bispectral index，BIS）、肌松、SEP和血流动力学．维持BIS范围35～45，肌松消失，血流动力学平稳，调节吸入麻醉药的呼气末浓度为0.3、0.6和0.9最低肺泡有效浓度（minimum alveolar concentration，MAC）时分别吸入不同浓度麻醉药．记录四肢吸入麻醉药前（基础值）、达到各呼气末浓度（T1、T2、T3）和吸入麻醉药吹尽时（回归值） SEP的潜伏期和波幅，并计算与基础值比较所得的百分率．结果与基础值的潜伏期比较，左上肢、左下肢和右下肢地氟醚组T1、T2及T3，右上肢地氟醚组T2及T3，左上肢、左下肢和右上肢七氟醚组T2及T3，右下肢七氟醚组T1、T2及T3的潜伏期延长（P＜0.05），其百分率随着吸入麻醉药物剂量的增加，潜伏期随之延长；与基础值的波幅比较，左上肢、左下肢地氟醚组T1、T2及T3，右上肢地氟醚组T1，右下肢地氟醚组T1及T2，左上肢七氟醚组T1，左下肢七氟醚组T1及T3的波幅下降（P＜0.05），尤其在T1时下降最明显．与地氟醚比较，左上肢和左下肢T1、T2、T3的潜伏期和波幅、右上肢和右下肢T2、T3的潜伏期和右下肢T1的波幅，七氟醚的抑制作用小（P＜0.05）．结论地氟醚和七氟醚对SEP均有抑制作用，随着剂量的加大，抑制作用逐渐增强，并且地氟醚的抑制作用强于七氟醚．

Effects of Desflurane and Sevoflurane on Somatosensory Evoked Potentials in Patients Undergoing Neurosurgery

Objective To compare the effects of desflurane and sevoflurane on somatosensory evoked potentials （SEP） in patients undergoing spine neurosurgery. Methods Thirty patients with ASA grades Ⅰ-Ⅱand undergoing spinal deformity orthopaedic surgery were selected and divided into two groups： desflurane group and sevoflurane group （n=30） . Bispectral index （BIS）,the state of muscle relaxation, SEP and hemodynamics were monitored during operation. By maintaining the BIS in the range of 35-45,the state of muscle relaxation disappeared and hemodynamic became stable. Adjust the concentration of anesthetic step by step from 0 to 0.3, 0.6 and 0.9 maximum alveolar concentrations （MAC）, then inhaled different concentrations of drugs. Record the incubation period and amplitude of SEP before inhaling anesthetics （based on the value）, in the moment of achieving each inhaled concentration （ T1, T2 and T3） , and the moment that the inhaled anesthetics blows completely （regression value） . The percentages of T1, T2, T3, and the regression value compared with basic value were＆amp;nbsp;calculated.Results Compared with the basic value, T1, T2 and T3 of left arm, left leg and right leg in desflurane group, T2 and T3 of right arm in desflurane group, T2 and T3 of left arm, left leg and right arm in sevoflurane group,and T2 and T3 of right leg in sevoflurane group showed incubation period delaying （ P〈0.05） . And the incubation period extended along with the increase of inhaled anesthetics dosage. Compared with the basic value,T1,T2 and T1 of left arm and left leg in desflurane group,T1 of right arm in desflurane group, T1 and T2 of right leg in desflurane, T3 of left arm in sevoflurane group, T1 and T3 in left leg in sevoflurane group had decreased amplitude （P 〈 0.05）, especially T1. Compared with desflurane, sevoflurane showed a weaker inhibition effect on the incubation period and amplitude of T1,T2,T3 of left arm and left leg,T2 and T3 of right arm and right leg, and the amplitude of T1 of right leg （ P〈 0.05） . Conclusion Both of desflurane and sevoflurane have inhibition effect on SEP. The inhibition effect gradually strengthens along with the increasing of dose. The inhibition effect of desflurane is stronger than sevoflurane.