论文部分内容阅读
目的探讨选择性头部亚低温对缺氧缺血新生猪脑血流的影响。方法生后7 d龄新生猪16头随机分为三组:缺氧缺血常温组(n=6)、缺氧缺血亚低温组(n=6)和正常亚低温组(n=4)。采用双侧颈总动脉阻断和吸入6%的氧30 min制备新生猪缺氧缺血性脑损伤模型。亚低温组鼻咽部温度分别降到35℃和32℃,常温组维持正常体温(39℃)。采用彩色微球方法测定脑血流。结果正常亚低温组35℃和32℃时全脑血流分别降低到基础值的74%和52%(P<0.05),颞叶、顶叶、脑干和小脑降低较为明显。新生猪缺氧缺血后2 h、4 h和6 h全脑血流较缺氧缺血前降低,差异有显著性意义(P<0.05);缺氧缺血后4 h局部脑血流均显著降低,缺氧缺血后6 h海马、纹状体及丘脑脑血流仍较低(P<0.05)。缺氧缺血新生猪亚低温治疗后,35℃和32℃时全脑血流、局部脑血流与常温组相应的时间点比较差异没有显著性意义。结论新生猪缺氧缺血后脑血流降低。选择性头部亚低温可以显著降低正常新生猪脑血流,但对缺氧缺血新生猪脑血流没有显著影响。
Objective To investigate the effects of selective head hypothermia on cerebral blood flow in newborn piglets with hypoxic-ischemic condition. Methods Sixteen newborn pigs at 7 days of age were randomly divided into three groups: normoxic and ischemic group (n = 6), hypoxic-ischemic hypothermia group (n = 6) and normal mild hypothermia group (n = 4) . Neonatal pigs with hypoxic-ischemic brain damage model were prepared by bilateral carotid artery occlusion and inhalation of 6% oxygen for 30 min. The hypothermia group nasopharyngeal temperature dropped to 35 ℃ and 32 ℃, normal temperature group maintained normal body temperature (39 ℃). Blood flow was measured by color microspheres method. Results In the mild hypothermia group, the cerebral blood flow decreased to 74% and 52% of the baseline at 35 ℃ and 32 ℃, respectively (P <0.05). The temporal lobe, parietal lobe, brainstem and cerebellum decreased significantly. The neonatal pigs had less cerebral blood flow at 2 h, 4 h and 6 h after hypoxia-ischemia than that before hypoxia-ischemia, the difference was significant (P <0.05). Local cerebral blood flow at 4 h after hypoxia-ischemia (P <0.05). Cerebral blood flow in the hippocampus, striatum and thalamus was still low 6 h after hypoxia-ischemia (P <0.05). Hypoxic-ischemic neonatal pig hypothermia treatment, 35 ℃ and 32 ℃ when the whole cerebral blood flow, local cerebral blood flow and normal temperature group corresponding time point difference was not significant. Conclusion Newborn pigs have decreased cerebral blood flow after hypoxia-ischemia. Selective head mild hypothermia can significantly reduce the normal neonatal pig cerebral blood flow, but no significant effect on cerebral blood flow in hypoxic-ischemic neonatal pigs.