高温高湿环境下颅脑损伤犬的血液流变学变化及依托咪酯的神经保护作用

Hemorheology changes and the neuroprotection of etomidate in dogs with craniocerebral injury under hyperthermia and hyperhumidity environment

目的:观察高温高湿环境下颅脑火器伤及伤后使用非巴比妥类镇静剂依托咪酯对犬血液流变学以及神经细胞的影响。方法:实验于2004-07在湛江市野外环境及解放军第四二二医院神经外科完成。选用健康成年杂种犬18只,随机分为常温对照组(对照组)、高温高湿颅脑火器伤组(火器伤组)和高温高湿颅脑火器伤依托咪酯用药组(依托咪酯组),每组6只。①火器伤组和依托咪酯组在高温高湿环境中[环境温度(58±7)℃,相对湿度39%～52%]暴露30min后使用军用手枪于狗额部眶上突旁,距头部30cm处冠状方向,角度略偏前方眶部约10°出弹,制做颅脑火器伤模型。伤后火器伤组动物立即腹腔注射5mL生理盐水,依托咪酯组动物伤后立即腹腔注射1.5mg/kg依托咪酯,于伤前及伤后2h测量两组犬的体温及进行血液流变学分析,并处死动物行脑组织标本电镜检查。②对照组动物于常温下观察2h后处死取脑组织标本行病理学检查。③比较火器伤组、依托咪酯组火器伤后2h的体温、血液流变学与对照组的差异,以及各组犬脑组织病理学变化。结果:每组6只犬均纳入结果分析。①实验后2h各组动物体温和血液流变学比较:火器伤组和依托咪酯用药组动物体温较对照组升高[(39.75±0.42),(40.08±1.27)和(34.40±0.38)℃],但无显著性差异(P>0.05);对照组、火器伤组和依托咪酯组血液流变学高切、中切、低切及血浆黏度变化不显著(P>0.05)。②脑组织病理学变化:火器伤组动物脑神经细胞减少,细胞胞浆内异染色体减少并边集,轴索损伤和脱髓鞘改变;尚存的神经细胞内可见多数线粒体肿胀、嵴减少或消失,内质网和高尔基氏体结构紊乱。依托咪酯组线粒体数量较多结构完整,内质网和高尔基氏体结构排列相对整齐,脑损伤程度较火器伤组减轻。结论:高温高湿环境下的颅脑火器伤,以及药物依托咪酯干预处理对犬血液流变学影响不显著;但伤后立即给予依托咪酯干预对高温高湿环境下颅脑火器伤犬的脑组织神经元细胞发生了明显的保护作用。

AIM:To study the effect of etomidate on hemorheology changes and nerve cells in dogs with craniocerebral firearm injury under hyperthermia and hyperhumidity environment. METHODS:The experiment was performed in the open country of Zhanjiang and the Department of Neurosurgery of the 422 Hospital of Chinese PLA in June 2004.In hyperthermia and hyperhumidity environment, 18 healthy grown crossbred dogs were divided into three groups: control group in common temperature, craniocerebral firearm injury group in hot and humid environment and etomidate group with six dogs in each group.①The ambient temperature of injury group and etomidate group was(58±7)℃,and the relative humidity was 39%52%.The dogs were shot by military pistol at the point 30 cm distant to the head in coronal direction with 10°leaning to the rim to make models of craniocerebral firearm injury.After injury,the dogs in injury group were injected with 5 mL saline, or 1.5 mg/kg etomidate,respectively.Body temperature and hemorheology changes were measured before and 2 hours after injury,and brain tissue was obtained for pathological examination under electron microscope after the dogs were killed.②Brain tissue in the control group was obtained for pathological examination at normal temperature 2 hours after decapitation.③Temperature, humorheology and pathological changes in the injury group and etomidate group were compared with those in the control group.RESULTS:Six dogs in each group were involved in the result analysis. ①Comparison of body temperatures and hemorheology two hours after experiment: Body temperature in the craniocerebral firearm injury group and etomidate group temperatures was higher than that in the control group[(39.75±0.42),(40.08±1.27)and(34.40±0.38)℃],but there was no significant difference(P >0.05).There were no significant changes of plasm visosity among control,firearm injury and etomidate groups(P >0.05).②Pathological changes of brain tissue:Nerve cells in the injury group were decreased.Allosome in cell plasm decreased or disappeared. Endoplasmic and golgi complex structure were disordered.But mitochondrial strcture in etomidate group were intact.Endoplasmic and golgi complex structure were relatively wellarranged.The degree of brain injury was milder in the etomidate group than in the firearm injury group.CONLUSION:Insignificant effect of etomidate on hemorheology changes after craniocerebral firearm injury is found under hyperthermia and hyperhumidity environment.But etomidate intervention immediately after craniocerebral firearm injury play a neuroprotective role under hyperthermia and hyperhumidity environment.