The Experimental study for establishment of safty cargioplegia in neonatal open heart surgery

保护缺血心肌一直是新生儿心脏直视手术的主要问题。虽然威斯康星大学（UW）溶液对保存其他器官是有效的，但在15-20ºC的低温条件下，它的保护作用会降低，这是心脏直视手术时的典型温度。由于这种效率的降低是由于UW溶液的高钾浓度造成的，我们开发了一种低钾版本的UW溶液（LPUW），用钠离子取代大部分钾离子，使钾和钙的浓度与圣托马斯医院心脏麻痹溶液2号（STS） （K: 16 mM,Ca: 1.2 mM）相同。研究了LPUW在15 ~ 20个疗程内对幼兔离体心脏（3 ~ 6 d）低温缺血后心功能的恢复情况，并与常规高钾UW溶液和STS进行了比较。使用改良的Krebs-Henseleit碳酸氢盐缓冲液（KH）。在工作模式下灌注30分钟后，给离体心脏注射四种停搏液中的一种。在15℃或20℃下分别维持缺血180分钟和360分钟（共8组，每组7个样本）。随后再次灌注Langendorff模式15分钟，工作模式30分钟。记录停搏前后的血流动力学参数，并进行比较。缺血后恢复主动脉流百分比360分钟在20゚C 40.3 (SY。+ -。)113.3%,79.3 (SY。+ -。)10.0%,64.3 (SY。+ -。)11.9%,和43.9 (SY。+ -。)(意思是(SY。+ - 15.9%。[) HPUW、LPUW、STS、KH的标准差。4种溶液中LPUW的保护效果最好（p<0.05），而HPUW的保护效果明显低于LPUW和STS （p<0.01）。在15 C缺血180分钟的情况下，观察到类似的趋势，尽管LPUW和STS之间没有显著差异。心肌缺血后三磷酸腺苷和磷酸肌酸浓度在LPUW组趋于升高，但LPUW与STS组无显著差异。结论：LPUW溶液在15 ~ 20oc范围内对离体兔心脏低温缺血的恢复效果优于常规UW溶液。本观察结果支持LPUW溶液在新生儿心内直视手术中的临床应用。少

Protection of the ischemic myocardium has been a major problem with open heart surgery in the neonate. Although University of Wisconsin (UW) solution is effective for the preservation of other organs, its protective effects are reduced in hypothermic conditions between 15-20 ﾟC,which is the typical temperature during open heart surgery. As this reduction in efficiency is due to the high potassium concentration of UW solution, we developed a lowpotassium version of UW solution (LPUW), replacing most of the potassium ions with sodium ions and making the concentration of potassium and calcium the same as in St. Thomas's Hospital cardioplegic solution No.2 (STS) (K : 16 mM,Ca : 1.2 mM). Recorery of cardiac function from hypothermic ischemia between 15-20 ﾟC was tested in isolated hearts from newborn rabbits (day 3-6) perfused with LPUW and results were compared with those obtained using conventional high-potassium UW solution and STS.Modified Krebs-Henseleit bicarbonate buffer (KH) was use … More d to represent hypothermia alone. After perfusing in the working mode for 30 minutes, the isolated heart was injected and arrested with one of the four cardioplegic solutions. Ischemia was maintained for either 180 minutes at 15 ﾟC of 360 minutes at 20 ﾟC (a total of 8 groups, each consisting of 7 samples). Subsequently, the heart was perfused again for 15 minutes in Langendorff mode and 30 minutes in the working mode. Hemodynamic parameters were recorded before and after the arrest, and subsequently compared. Percent recovery of aortic flow after ischemia for 360 minutes at 20 ﾟC was 40.3(]SY.+-。[)113.3 %, 79.3(]SY.+-。[)10.0%, 64.3(]SY.+-。[)11.9%, and 43.9(]SY.+-。[)15.9% (mean (]SY.+-。[) standard deviation) for HPUW,LPUW,STS,and KH,respectively. LPUW demonstrated the most favorable protective effects among the four solutions (p<0.05), while HPUW demonstrated significantly worse protection compared with LPUW and STS (p<0.01). In the case of ischemia for 180 minutes at 15 ﾟC,a similar tendency was observed, although no significant difference was observed between LPUW and STS.Concentrations of adenosine triphosphate and creatine phosphate in the cardiac muscle after ischemia tended to be higher with LPUW,although no significant difference was observed between LPUW and STS.In conclusion, LPUW solution was superior to conventional UW solution with regard to recovery from hypothermic ischemia between 15-20 ﾟC of the isolated heart from neonate rabbit. This observation supports the clinical application of LPUW solution for open heart surgery in newborn patients. Less