弥散加权成像技术对猪心肺复苏后亚低温治疗脑损伤的效果评价  

The evaluation of cerebral function by diffusion weighted imaging after mild hypothermia therapy in a procine model of cardiac arrest

作　　者：唐子人[1] 李春盛[1] 彭朋[2] 蒋涛[2] 赵红[1] 龚平[1] 花嵘[1] 

机构地区：[1]首都医科大学附属北京朝阳医院急诊科,北京100020 [2]首都医科大学附属北京朝阳医院放射科,北京100020

出　　处：《中华急诊医学杂志》2014年第6期630-634,共5页Chinese Journal of Emergency Medicine

基　　金：国家自然科学基金（81372025）

摘　　要：目的：通过弥散加权成像（DWI）技术研究心肺复苏成功后72 h内脑功能、脑水肿的动态变化趋势和亚低温的脑保护作用。方法五指山猪33只，致颤8 min后按标准心肺复苏操作，复苏成功30只，随机分为低温组（15只）和常温组（15只）。低温组在自主循环恢复后给予血管内降温，将核心体温以最快速度降至33℃，维持低温12 h后被动复温（0.5℃/h）至37℃，常温组不干预温度，两组动态监测血流动力学变化，于基础状态和ROSC后6 h，12 h，24 h，72 h行脑组织磁共振弥散加权成像技术检测。统计学处理采用 Student t 检验、重复测量方差分析及Kaplan-Meier生存分析。结果低温组72 h成活率显著优于常温组（73.3％vs.40％，P＜0.05），72 h神经功能缺损评分显著优于常温组（43.81分vs.119.50分，P＜0.01）。DWI结果显示，低温组表观弥散系数值较常温组降低幅度小，DWI图像相同时间点脑水肿程度较常温组轻。结论心脏骤停复苏后早期即出现了严重的脑水肿，脑水肿在复苏后6h最严重，此后逐渐恢复；亚低温疗法一定程度上可以提高复苏成功率，减轻脑细胞水肿，对脑复苏具有重要的保护作用；弥散加权成像技术可以对复苏后脑损伤进行动态监测，对干预措施进行动态评价。Objective To evaluate the effects of mild hypothermia therapy on cerebral function and edema as assessed by magnetic resonance imaging （MRI ） during the first 72 hours after restoration of spontaneous circulation （ROSC）in a porcine model.Methods Ventricular fibrillation was induced in 33 Inbred Wuzhishan miniature swine.After ventricular fibrillation untreated for 8 min,standard CPR was initiated and 30 animals got ROSC.The ROSC animals were randomly （random number）assigned to normothermia group （n=15 ） and hypothermia group （n =15 ）.The hypothermia group immediately received endovascular cooling to regulate temperature to 33 ℃,which was maintained for 12 h,followed by passive rewarming at 0.5 ℃/h to 37 ℃.The two groups were scanned to get Diffusion-weighted imaging （DWI）at baseline （before experiment）,6 h,12 h,24 h,and 72 h after ROSC.The statistical analysis was carried out with Student t test,One-way repeated-measures and Kaplan-Meier survival analysis.Results Compared with the normothermia group,the hypothermia group exhibited a higher 72-h survival rate （73.3% vs.40%,P〈0.05）,lower neurological deficit scores （43.81 vs.119.50;P〈0.01）,a lesser decrease in the apparent diffusion coefficient during DWI and milder cerebral edema on DWI image. Conclusions Cerebral edema occurred at early stage after ROSC.Cerebral edema was worst at 6 hours after ROSC and then subsided gradually.Hypothermia therapy could reduce cerebral edema and produce a protective effect on neurological function.MRI could effectively reflect the underlying trend of cerebral injury of swine within the first 72 h after ROSC,and demonstrated that hypothermia could reduce brain edema, increase cerebral blood flow,and reduce the production of toxic metabolites.DWI could monitor brain injury after resuscitation and could be used to evaluate the efficacy of hypothermia intervention dynamically.

关 键 词：心脏骤停 心肺复苏 亚低温治疗 弥散加权成像 磁共振成像技术 脑保护 心室纤颤 表观弥散系数 脑水肿 

分 类 号：R541.78[医药卫生—心血管疾病]