温氧合血停搏液诱导停搏及复苏再灌对心肌保护的作用

Experiemental Study on Protective Effects of Warm Oxygenated Cardioplegic Blood Induced Cardiac Arrest and Resuscitative Reperfusion

为观察不同灌注方法改善心肌保护的效果，用杂种犬２１只，随机均分为３组：Ｉ、Ｉ组分别用冷晶体、冷氧合血停搏液间灌，ＩＩ组在Ｉ组基础上加用温氧合血停搏液诱导停搏及复苏再灌。于体外循环下心肌缺血９０分钟再灌注３０分钟期间，观察心脏电机械活动、转流前后左心功能、心肌ＣＰＫ释放量及摄氧量、心肌含水量及超微结构变化。结果显示：Ｉ、ＩＩ组复苏后血流动力学的稳定性、左心功能恢复优于Ｉ组，ＣＰＫ释放量、心肌含水量及超微结构损害程度明显低于Ｉ组。ＩＩ组心肌停搏及复苏极少出现室颤、自动复跳率高、心肌摄氧量高于Ｉ组；再灌注３０分钟时，心肌ＣＰＫ释放量明显低于Ｉ组，心肌水肿及超微结构损伤较Ｉ组略轻。表明冷氧合血停搏液间灌法具有明显减轻心肌缺血和再灌注损伤的作用，而温氧合血停搏液诱导停搏及复苏再灌的心肌保护效果更佳。

Aim:To assess the effects of warm oxygenated cardioplegic blood on myocardial protection during ischemic cardiac arrest and resuscitative reperfusion.Method:The study consisted three groups of mongrel dogs.Group I (n=7) received intermittent cold crystalloid cardioplegic solution.Group II (n=7) received cold oxygenated cardioplegic blood.In group III (n=7),cardiac arrest was induced and resuscitated with warm oxygenated cardioplagic blood.Assessments of cardial electro-mechanical activities,left ventricular function,hemodynamic parameters,cardial water content,oxygen extraction and ultrastructural changes were done at 90 minutes after ischemic cardiac arrest and 30 minutes after reperfusion.Result:The time interval for inducing cardiac arrest in group III was much longer than in group I and II (P<0.05).High incidence of spontaneous recovery of sinus rhythm and lower incidence of arrhythmia were seen in group III.The duration for getting out oxygen debt was the shortest in group III and longest in group I (the respective P<0.01 and P<0.05).Hemodynmic changes mainly manifested in postoperative a significant or marked drop of LVP and MAP in 3 groups as compared with their preoperative values (P<0.05-0.01),but,the greatest drop of LVP and MAP was seen in group I as compared with group II (P<0.05) and group III (P<0.01).The elevation of LAP and decrease of AF were significant as compared with the preoperative values only in group I.The release of CPK increased in 3 groups during 60 minutes of ischemic arrest,but,the markedly significant increase was present in only group I (P<0.01).The amplitude of CPK increase in group II and II was much lower than that in group I (P<0.05 and P<0.01,respectively).After 30 minutes of reperfusion,the CPK concentration in group III was obviously lower than group I (P<0.01) and significantly lower than group II (P<0.05).The greatest amount of oxygen extraction in group III as compared with group I (P<0.05) and group II (P<0.05) was only seen in the early reperfusion.The myocardial water contents at 30 minutes of reperfusion were markedly increased in contrast to that of 90 minutes of ischemia in 3 groups (all P<0.01). The ultrastructural changes were the mildest in group III (grade I) and milder in group II (grade I-II) and worst in group III (grade II-III).Conclusion:To use warm oxygenated cardioplegic blood to induce cardiac arrest during ischemia and reperfuse the myocardium during resuscitation offers better myocardial protective effects than cold oxygenated cardioplegic blood and cold crytalloid cardioplegic solution.