摘要
目的:观察犬脑选择性降温对缺血性脑组织的保护作用和对心血管机能的影响.方法:夹闭左侧颈总动脉、双侧椎动脉、左侧颈外静脉,自右侧颈内动脉灌人低温灌注液以降低脑温.将颅脑回流的低温稀释静脉血超滤并复温至38℃后再输入体循环.观察低温期间血压等指标的变化.结果:10只犬中有9只完成了脑的选择性降温.冷灌注开始瞬间即出现脑缺血性反应,平均动脉血压升高32±14mm Hg,心率加快13±7次/分,持续2～5分钟.降温过程中血压由基础值127.7±9.9 mm Hg,渐降至93.5±14.6mm Hg. 9只犬延髓温度降至25～20℃期间,平均动脉压迅速降至30～50mm Hg.心率减慢至60～97次/分.对其中6只犬,开放椎动脉结合应用多巴胺,血压、心率可于4.1±1.8分钟内渐恢复至接近正常水平,术后神经功能正常.另3只犬因长时程过低血压而死亡.结论:犬脑选择性降温,可防止脑组织的缺血性损伤,但延髓降温使心血管中枢功能受到抑制而出现明显血压变化.
Objective: To evaluate the protective effect of selective cerebral hypothermia on canine ischemic brain and its suppressive effect on the cardiovasculau function. Methods: After the left carotid artery(CA), the left jugular vein(JV), and both vertebral arteries (VA) were clamped simultaneously, cold solution was immediately perfused into the intetnal carotid artery to produce selective cerebral hypothermia. We used the right JV to extract the hypothermic diluted blood for ultrafiltration and rewarming and perfuse the warm blood (38℃) into the right atrium. Results: In 9 of 10 dogs, the brain temperature decreased selectively. The ligation of the left CA and both VAs together with the selective hypothermic perfusion immediately produced a cerebral ischemic response (CIR) manifest as an increase in the mean arterial blood presure (MABP, 32± 14mmHg) and heart rate (HR, 13 ± 7 beats/min) which lasted for 2 ～ 5minutes usually. Then during the further cooling of the brain stem, the MABP decreased slowly from the baseline level of 127.7 ± 9.9mmHg to 93.5 ± 14.6mmHg, and decreased rapidly to 30 ～ 50mmHg with the heart rate decreased to 60 ～ 97 beats/min as the medulla temperature decreased to 25 ～ 20℃ in 9 dogs. Releasing one or two clamps on the VAs in combination with an intravenous injection (2.0 ～ 2.5mg/kg/h) of Dopamine resumed 6 dogs' MABP and HR to near baseline levels in 4.1 ± 1.8 minutes. The 6 animals survived the operation without evidence of neurological deficits, and the other 3 died of long - term serious decrease in arterial blood pressure. Conclusions: Selective cooling of the brain has a protective effect on cerebral ischemia. The suppressive effect of hypothermia on cardiovascular center in medulla may elicit serious decrease in arterial blood pressure.
出处
《福州总医院学报》
2000年第2期12-14,共3页
Journal of Fuzhou General Hospital
关键词
血压
椎动脉
正常
左侧
脑组织
延髓
心率
观察
降温
双侧
Profound hypothermia
Intra-carotid
Cold perfusion
Cardiovascular center
Dog
