多巴胺对兔心肺复苏早期血流动力学及脑氧代谢的影响

Effect of dopamine on hemodynamics and cerebral oxygen metabolism in the early stage of post-resuscitation in rabbit with cardiac arrest

目的 观察不同剂量多巴胺对家兔心肺复苏（CPR）早期血流动力学及脑氧代谢 的影响。方法 根据多巴胺的不同剂量将健康成年家兔按随机数字法分为4 组：对照组（control group, CG）、低剂量组（low dose group, LG）、中剂量组（moderate dose group, MG）、大剂量组（high dose group, HG），每组15 只。电诱导致颤并进行CPR 直至每组自主循环恢复（ROSC）家兔达到 10 只。记录各组ROSC 即刻、15 min、30 min、60 min、120 min 时的心输出量（CO）、平均动脉 压（MAP）、心率（HR）、外周血管阻力指数（SVRI）、脑局部组织血氧饱和度（TOI），120 min 后处死家兔取脑组织行HE 染色，观察各组神经细胞损伤程度。各时间点组间比较采用重复测量的 方差分析，多组定量资料的比较如符合正态性检验采用单因素方差分析，两两比较采用LSD-t 检 验；多组二分类资料采用χ2 检验或Fisher 确切概率法检验；生存曲线差异的比较采用Log-rank 检 验，以P〈0.05 为差异有统计学意义。结果 各组间ROSC 率差异无统计学意义；与CG 和LG 相比， MG 的ROSC 时间更低（277±15 vs. 190±12，P〈0.01 ；252±16 vs. 190±12, P=0.016）， 且120 min 生存率更高（20% vs. 90%, χ2=9.899, P= 0.005; 30% vs. 90%, χ2=7.5, P=0.02）； ROSC 后各时间点 MG 的CO 均高于其余各组（均P〈0.05）；MG、HG 在ROSC15 min 后各时间点MAP 均明显高于 CG、LG（均P〈0.05）；ROSC 后各时间点HG 的SVRI 均明显大于同时刻其余各组（均P〈0.05）； 在ROSC 15 min、30 min 时MG 的TOI 值明显大于同时刻其余各组（均P〈0.05）；MG 和HG 的中 位生存时间均大于CG 和LG（均P〈0.05）。平均每高倍镜视野下MG 坏死细胞数（28.4±1.0）显 著低于其余各组（CG： 41.2±1.5 ；LG ：41.0±2.0 ；HG ：39.6±1.9）（均P〈0.01）。结论 中等剂量 多巴胺可同时维持ROSC 家兔MAP、CO 在较高水平，对家兔早期脑氧代谢产生更有益的效果。

Objective To observe the effects of dopamine in different doses on hemodynarnics and cerebral oxygen metabolism in the early stage of post-resuscitation in rabbit with cardiac arrest. Methods Healthy adult rabbits were randomly（random number） divided into 4 groups according to the different doses of dopamine administration： control group （CG）, low dose group （LG）, medium dose group （MG）, high dose group （HG）, （n=15 in each group）. Ventricular fibrillation （VF） was induced by electricity and cardiopulmonary resuscitation （CPR） was performed subsequently as the experiment designed. When 10 rabbits with restoration of spontaneous circulation （ROSC） were got each group, it was enough for experiment carried out. Cardiac output （CO）, mean arterial pressure （MAP）, heart rate（HR）, systemic vascular resistance index （SVRI） and the cerebral local tissue blood oxygen saturation （TOI） were observed at 0 min, 15 min, 30 min, 60 min, 120 min after ROSC. The animals were sacrificed at 120 min after ROSC, brain tissues were harvested for study by using HE staining. Repeated measure analysis of variance was used to determine the statistical significance among the four groups at different intervals. Multi-group quantitative data was analyzed by one way ANOVA and then further by LSD test for multiple comparisons. Chi-square test or Fisher＇s exact probabilities was applied for multi-group binomial classification variable. Log-rank test was used for comparisons of survival curves in four groups. A two- tailed value of P〈0.05 was considered statistically significant. Results There were no differences in the rate of ROSC among groups. Compared with CG and LG, ROSC time was shorter in MG （ 277±15 vs. 190±12, P〈0.01 ; 252±16 vs. 1904-12, P=0.016 ） with higher 120 min survival rate （ 20% vs. 90%, x2=9.899, P=0.005; 30% vs. 90%, x2=7.5, P=0.02 ） . CO was higher in MG than that in other groups at all given intervals in the early stage of post-resuscitation（P〈0.05）. MAP levels were significantly higher in MG and HG compared with CG and LG at given intervals 15 min after ROSC （P〈0.05）. SVRI was significantly higher in HG than that in other groups at all given intervals after ROSC （P〈0.05）. Compared with other groups, the TOI levels in MG were significantly higher than that in other groups at 15 min and 30 min after ROSC （P〈0.05）. The median survival time in MG and HG was significantly longer than that in CG and LG. The number of cellular necrosis in MG （ 28.4±1.0 ） was significantly fewer than that in other groups （ CG 41.2±1.5; LG 41.0±2.0 ; HG 39.6±1.9 ） （P〈0.01）. Conclusion The moderate dose of dopamine might maintain MAP and CO at a higher level meeting the cerebral oxygen metabolism in the early stage of post-resuscitation from cardiac arrest in rabbits.