异氟醚对大鼠局灶性脑缺血再灌注损伤脑电功率谱的影响

Effect of isoflurane on EEG frequency power spectrum and brain temperature during focal ischemia/reperfusion in rats

目的 探讨脑电功率谱、脑温监测在评价局灶性脑缺血再灌注损伤程度中的意义及异氟醚的治疗作用。方法 随机将 30只SD大鼠 (体重 2 80～ 32 0g)分为假手术组、缺血组、0 .8MAC异氟醚治疗组和 1 .3MAC异氟醚治疗组。假手术组不置线 ;缺血组用线栓法阻塞大脑中动脉 (MCAO) 2h ,拔除线栓恢复再灌注 ;异氟醚治疗组在留置线栓前吸入异氟醚 30min。在缺血再灌注不同时间监测记录脑电参数及鼓膜温度变化。结果 缺血组在MCAO早期缺血侧即可出现脑电波波幅降低 ,频率减慢 ,δ比率最大增高至缺血前的 62 .8% ,α比率最大降低至缺血前的 55 .1 % ;同时缺血侧脑温较非缺血侧明显降低 ,最大温差达 (0 .78± 0 .35)℃。异氟醚治疗组明显降低缺血期间δ比率的增高 ,增加α比率 ,再灌注后脑电恢复率较单纯缺血组明显改善 ,但两异氟醚组间无显著差异。结论 监测脑电功率谱 ,可衡量脑缺血的程度 ,尤以δ比率变化更为敏感 ;异氟醚可减轻局灶性脑缺血再灌注引起的脑电改变 。

Objective To evaluate the effect of isoflurane on EEG frequency power spectrum and brain temperature in a model of middle cerebral artery occlusion (MCAO) in rats.?Methods Thirty SD rats weighing 280-320 g were randomly divided into four groups. In sham-operation group animals received incison but no artery occlusion.In ischemia group animals subjected 2 hours of MCA occlusion by the intraluminal occlusion technique. In 0.8 MAC and 1.3 MAC isoflurane group animals inhaled 0.8 MAC and 1.3 MAC isoflurane 30 min before the onset of ischemia,EEG frequency power spectrum and periost temperature was monitored during ischemia and first 60 min after MCAO.?Results The ischemia group significantly decrease the amplitude and frequency of EEG in the ischemic hemisphere.The δ ratio increased to 62.8% and α ratio decreased to 55.1% of preischemic values.In comparing with non-ischemic hemisphere,temperature of ischemic hemisphere significantly decreased,maximum temperature difference was (0.78±0.35) ℃, whereas the decreased and increased degrees of δ and α ratios in isoflurane group were significantly lighter than those in ischemia group.?Conclusions The results suggested EEG frequency power spectrum monitoring is effective in the evaluation of cerebral ischemia injury and isoflurane can inhibit the increased extent of δ ratio and mitigated the focal cerebral ischemia reperfusion injury.