摘要
目的：通过观察高压电烧伤后家兔肠系膜微循环的动态变化，探索高压电对机体内脏微血管及微血流动力学的影响，为电烧伤后脏器损伤的防治提供理论依据。
方法：1. 实验动物分组：成年健康家兔30只，雌雄不拘，雌兔未孕，10只用于预实验，其余20只随机分为高压电烧伤组（简称电烧伤组）和假高压电烧伤组（简称对照组），每组10只。2. 实验前准备：称体重、编号，并记录结果；用1%戊巴比妥钠溶液麻醉家兔后，剪去其腹部（10×6cm２）及左上肢和右下肢大腿外侧（5×5cm２）的被毛，用10%硫化钠溶液在剪毛区脱毛，然后，将家兔置于20～25℃的实验室，自然干燥。3. 高压电烧伤动物模型的复制：高压电击系统由电阻箱、升压变压器、调压器、电流互感器、高压静电电压表等组成，将麻醉、脱毛后的家兔固定于绝缘兔台上，将两个电极钢板（每个面积4.5㎝２）连接变压器输出端电线，分别固定于家兔左上肢（入口—电流输入端）及右下肢（出口—电流输出端）脱毛区域，调额定电压至一万伏，电击5秒钟后断电，实验通过电流为1.8±0.15Ａ。电击即刻，家兔全身肌肉痉挛，解除电极后，接触电极区域肌肉及韧带炭化，高压电烧伤家兔模型复制成功。对照组进行假电实验，实验前打开电闸，保证无电流通过，其余过程同高压电动物模型复制。4. 家兔肠系膜微循环观察方法：在右侧腹直肌旁做长6cm的纵行中腹部切口，打开腹腔，找到盲肠，沿盲肠上寻
4～5cm，拉出此段回肠及肠系膜，选择有细小血管走行、脂肪少的部位作为观察区域，将拉出的肠系膜伸展于透明有机玻璃制成的灌流盒上，用WX-9B型微循环显微镜及视频图像分析系统，观测肠系膜微循环的动态变化，并记录结果。5. 观测时相及指标：对照组和电烧伤组均分为6个时相进行观测，分别为电烧伤即刻、电烧伤后30分钟、1小时、2小时、4小时、6小时（分别记录为T0、T1、T2、T3、T4、T5），观测指标分为微血管形态、微血管流态及微血管周围状态三部分，共13项指标。6. 观测结果处理：用SAS6.12统计学处理软件，对不同类型数据进行不同的统计学处理。
结果：1.对照组各时相肠系膜微循环的观测：对照组各时相间微循环状态无显著性变化，微血管形态大多自然弯曲，边缘光滑，镜下能清晰分辨血流方向，能区分微动静脉，微动脉的流速多为线流，微静脉的流速多为线粒流，毛细血管多为线粒流或粒线流，微血管中多无红细胞聚集。未见微血管异常舒缩，微动脉管径14.99±1.89μm，微静脉管径28.59±2.86μm，微血管周围多无渗出和出血。2.电烧伤后各时相肠系膜微循环的观测：高压电烧伤即刻（T0时相），家兔肠系膜微血管轻微迂曲、交叉，微动脉与微静脉均收缩，微动脉平均管径为12.81±1.48μm，微静脉平均管径为25.91±2.83μm，与对照组比较均有显著性差异（p＜0.05）。微血管血流状态与对照组比较无明显变化，管周有少量渗出，但无出血。高压电烧伤后30分钟（T1时相），镜下视野欠清晰，走行迂曲，少数僵直，微动脉持续收缩，其管径为11.77±1.33μm，与对照组比较有显著性差异（p＜0.001），微静脉收缩缓解，管径28.15±2.51μm，与对照组比较无显著性差
异（p＞0.05），毛细血管闭塞，出现空白区，血流减慢，红细胞聚集，微血管周围渗出增多，与对照组比较均有显著性差异。高压电烧伤后1小时（T2时相），微动脉收缩缓解，逐渐恢复正常，其管径为14.81±1.45μm，与对照组的管径比较无显著性差异（p＞0.05），微静脉在此时相开始扩张，平均管径为31.72±2.99μm，与对照组比较有显著性差异（p＜0.001），微血管血流速度及红细胞聚集程度有所缓解，但与对照组仍有显著性差异，大部分微血管中出现白微栓，管周渗出增多，部分家兔可见管周出血，且出血首先发生于微静脉。高压电烧伤后2小时（T3时相），镜下视野清晰度差，微动脉开始扩张，其管径为16.91±1.23μm，与对照组比较有显著性差异（p＜0.001），微静脉呈持续扩张状态，管径（34.46±3.06μm）进一步增宽，与对照组管径比较均有显著性差异（p＜0.001），微血管血流速度与红细胞聚集程度变化与对照组比较有显著性差异。微血管周围渗出、出血及白微栓增多。高压电烧伤后4小时、6小时（T4、T5时相）：微血管迂曲、交叉，边缘不齐，有颗粒感，微静脉与微动脉持续扩张状态。微血管血流速度与红细胞聚集程度变化与对照组比较有显著性差异，渗出、出血进一步增多。
结论：高压电烧伤可引起家兔肠系膜微循环紊乱，主要表现为：①电烧伤后家兔肠系膜的微血管形态、微血管流态及微血管周围状态均发生改变；②通过测量家兔肠系膜微血管管径发现，致伤即刻微动脉与微静脉均进入收缩状态，微静脉在短暂的收缩后开始扩张，并持续扩张状态，微动脉较微静脉收缩时间长，而后进入持续扩张状态，观测时相与高压电对微动脉与微静脉管径均有影响，且而者存在交互作
用；③微血管周围出血，随观察时相的延长而增多；④微血管流态变化较热烫伤轻，微血管流速大多为线粒流和粒线流，少数为粒流。⑤通过观测高压电烧伤家兔肠系膜微循环的变化，可以了解高压电烧伤后，远隔脏器血供及微循环变化情况，对指导临床治疗具有重要意义。
Objective: To objective the changes in mesenteric microcirculation of rabbits after high-voltage electric burn, to study the effect on microvascular and blood hydrodynamics by high-voltage electric and explore its mechanism, which may be offer theoretical foundation for the prevention and cure of organ injury after high-voltage electric burn.
Methord: 1.Group: 30 adult healthy rabbits, 10 rabbits of which are used to preliminary experiment and others are randomly divided into two groups, high-voltage electric burn group (electric burn group) and fake high-voltage electric burn group (control group), 10 rabbits of each group, regardless of sex . The female rabbits have not been pregnant. 2.Preparation: These rabbits are weighted and ordered, then their hair of abdomen(10×6cm2) and outboard of left-up limbs and right-down limbs (5×5cm2)are cut after being anesthetized, after that these areas are epilated by 10% sodium sulphide solution. Rabbits are layed in 20℃~25℃ laboratories, dry naturally. 3.Duplication of high-voltage electric burn model: High-voltage electric system is made up of resistance box, step up transformer, voltage regulator, current transformer and electrostatic voltmeter. Anesthetized rabbits are put on the insulated platform and are
joined into the 10,0000 volts high-voltage electric system for 5 seconds. Left-up limb is the entrance and right-down limb is the exit, electric current is 1.80±0.15A. The whole body muscles of rabbit convuled at the moment, and then skin, muscle, ligament in touch with the electrodes charcoaled after removing the electrodes. So high-voltage electric burn model is duplicated successfully. The progress of control group is the same as the electric burn group, but there isn’t electric current in the body of control group rabbit. 4.Observation of mesentric microcirculation of rabbits : Abdomen epilated rabbit is put on experiment platform. A slang(6cm) is maked on the right musculus rectus abdominis, the abdominal is opened, mesentery is put out, and then an area which has microvascular and less fat is selected as the observing area. The mesentery is put out and spread on the irritate and flow box which is made of transparent lucite to be observed. Fully exposed mesentery microcirculation is observed with WX-9B poly-position microcirculation instrument and its results are taken down. 5.Time phase and index: The time phases of control group and electric burn group are divided into six phases, immediately, 0.5h, 1h, 2h, 4h, 6h.(They are recorded as T0, T1, T2, T3, T4, T5). Observing indexes are divided into microvascular morphology, microvascular flow state and microvascular peripheral state, amount to 13 indexes. 6.Analysis of resulta: Different kinds of results are dealed with by using SAS6.12 software.
Results: 1.Mesentric microcirculation of every time phases
of control group: There are no remarkable changes between different time phases of control group. The microvascular crooks naturely, the edge of it is smooth. The direction of microvascular blood flow can be distinguished clarity under microscope. The velocity of microvascular blood flow is normal. Erythrocyte aggregation are not observed in microvascular. There are not peripheral exudation and hemorrhagia around microvascular. Diastole and contraction of microvascular is normal. The cabilers of arteriole and veinule are 14.99±1.89μm and 28.59±2.86μm. 2.Oservation of different time phases after high-voltage electric burn: T0 time phase: Microvascular of rabbits mesentery is tortuous and cross slightly. Arteriole and veinule are contracted. The calibers of arteriole and veinule are 12.81±1.48μm and 25.91±2.83μm, which are different from that of control group(p＜0.05). The velocity of microvascular blood flow is simlar to the control group’s. There is some peripheral exudation around microvascular. Hemorrhagia is not observed at this time phase. T1 time phase: At this time phase, microvascular is contracted stronghly and tortuous, a few stiff. Arteriole is contracted. The caliber of art
引文
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