肢体缺血预处理对婴幼儿心脏手术后心肌保护研究

目的探讨婴幼儿肢体缺血预处理（RIPC）的安全性及其对心脏的保护作用。方法以60例体重7Kg以下的室间隔缺损婴幼儿为研究对象，处理组（30例）手术前2次上肢RIPC，体外循环围手术期多个时间点监测乳酸脱氢酶（LDH）、肌酸激酶（CK）及其同工酶（CK—MB）、血清肌钙蛋白I（TnI）多个心肌酶学指标、冠脉丙二醛（MDA）、超氧化物歧化酶（soD）及心肌热休克蛋白（HSP70）含量，观察预处理后肢体疼痛及感觉障碍等。结果肢体RIPC后无疼痛、活动及感觉障碍等异常情况；处理组术前LDH、CK及TnI高于对照组，各酶学指标术后较对照组均有不同程度的降低，且部分时间点有统计学意义；处理组冠脉MDA低于对照组，SOD高于对照组；处理组心肌HSP70表达增高。结论婴幼儿肢体RIPC安全可行，并能减少心肌缺血再灌注后心肌酶的释放、氧自由基生成。上调HSP表达，对缺血再灌注心肌存在一定程度的保护作用。

Limb ischemic preconditioning reduce myocardial ischemia reperfusion injury for infants undergoing cardiac operation

Objective To study the feasibility and safety of limb remote ischemic preconditioning (RIPC) in infants and explore the protective effect on myecardium ischemia reperfusion injury for infants undergoing cardiac operation under cardiopulmonary bypass. Methods 60 infants weight less than 7 kilograms with ventricular septal defect were enrolled into the study. 30 of them (RIPC group) were ischemic preconditioned two times (24 hours and 1 hour preoperatively) by three cycles of iscbemia (5 minutes for each) and reperfusion on the left upper arm using a blood pressure cuff. Serum lactate dehydrogenase (LDH), creatine kinase (CK) and its isoenzyme (CK-MB), and tro-ponin I (TnI) ; malondialdehyde (MDA) and superoxide dismutase (SOD) was preoperatively detected. The expression of heat shock pro-tein 70 (HSP 70) in cardiomyocytes was determined by western blot analysis. The surgical outcome including limb movement and sensory function was also recorded. Results No limb disability or sensory disturbance or no other surgical complications was found in all infants. LDH, CK, TnI at the beginning of operation in RIPC group was higher than those in control group. After operation, leakage of heart enzymes were attenuated in RIPC group, and the serum concentration of enzymes were lower than those in the control group. The RIPC group had low coronary sinus venous concentration of MDA but high SOD. The expression of HSP70 was upregulated in cardiomyocytes of RIPC group. Conclusion The limb RIPC can be done easily and safety in infants, and BIPC can reduce the leakage of myocardial enzymes and upregu-late the expression of HSP, which possess protective effect on myocardial IRI.