6-氨基己酸对体外循环时纤溶系统的影响及与抑肽酶的对比研究

目的　探讨儿童体外循环 (CPB)心脏手术期间纤溶系统的动态变化 ,观察 6 氨基己酸 (EACA)对纤溶系统有关变量及术后出血和输血的影响 ,并与抑肽酶比较。方法　随机选择 45例择期手术的非紫绀型先天性心脏病患儿 (体重 10～ 3 0kg) ,分为抑肽酶用药组 (A组 ,15例 )、6 氨基己酸组 (B组 ,15例 )、对照组 (C组 ,15例 )。于麻醉诱导后切皮前 (T1)、CPB 15min (T2 )、CPB 3 0min (T3)、术后 2h (T4 )、术后 2 4h (T5)分别测定组织型纤溶酶原激活剂 (t PA)和纤溶酶原激活物抑制物 1(PAI 1)活性、D二聚体 (D D)含量、红细胞压积 (HCT) ,记录术后 2 4h心包纵隔引流量 (失血量 )及术中术后输库血量。结果　①对照组 :术中t PA活性较术前显著升高 (P <0 0 1) ,术后 2h仍高于术前 (P <0 0 5 ) ,术后 2 4h恢复正常 ;PAI 1活性术中及术后 2h与术前相比无显著变化 (P>0 0 5 ) ,术后 2 4h较术前明显增高 (P <0 0 5 ) ;t PA/PAI 1比值术中及术后 2h均显著高于术前水平 (P <0 0 1) ,术后 2 4h恢复正常 ;D D含量术中至术后 2 4h均显著高于术前 (P <0 0 1)。②用药组 (A组和B组 ) :术中及术后 2ht PA活性均显著低于对照组 (P <0 0 5 ) ;术后 2hPAI 1活性明显高于对照组 (P <0 0 5 ) ;术中及术后D D含量均显著低于对

Comparison of the effects of epsilon-aminocaproic acid and aprotinin on fibrinolytic system in children undergoing cardiopulmonary bypass

Objective To investigate dynamic changes in the fibrinolytic system in open heart surgery with cardiopulmonary bypass (CPB) and the protective effects of aprotinin and epsilon aminocaproic acid (EACA) on fibrinolytic system and postoperative bleeding and transfusion.Methods Forty five children with acyanotic congenital heart disease were included in this study. The patients were randomized into three groups:group A (apotinin;AP),group B (EACA) and group C (control).Blood samples were taken from patients in the study groups at the following time points:after the induction of anesthesia,prior to skin incisions,15 minutes after the onset of CPB,30 minutes after the onset of CPB,2 hours after the end of the operation,24 hours after the end of the operation. Measured parameters include tissue type plasminogen activator (t PA) activity, plasminogen activator inhibitor (PAI) activity,D dimer (D D),hematocrit value, blood gas variables and activated clotting time (ACT).24 hours′amount of postoperative bleeding and the transfusion amount were recorded.Results t PA activity in group C was elevated significantly during the operation and 2 hours postoperatively ( P <0.05),but elevated significantly 24 hours postoperatively compared with that of preoperation ( P <0 05).The ratios of t PA/PAI 1 increased significantly during the operation and 2 hours postoperatively ( P <0 01),and returned to normal levels 24 hours later.Content of D D increased significantly both during and after operation ( P <0 01).Both of t PA activities in group A and group B were remarkably lower than that in group C during the operation and 2 hours postoperatively ( P <0 05). PAI 1 activities in group A were significantly higher than that in group C ( P <0 05).24 hours′amounts of bleeding in group A and B were reduced 46% and 42% respectively compared with that in group C.The use of homologous blood in group A and B during and after operation was reduced by 40% and 35% respectively. There were no differences with respect to bleeding and homologous blood transfusion between group A and group B ( P >0 05).Conclusion ① This study shows that the fibrinolytic system is activated remarkably during CPB.The main mechanism of this phenomenon is due to the increase of t PA and the imbalance of t PA and PAI 1 in plasma.The D D increase in plasma during and after the operation also contributes to the postoperative bleeding to some extent.② EACA can inhibit, as effective as AP,the activation of fibrinolytic system during CPB in children patients,and reduce the postoperative bleeding and the need of homologous blood remarkably.Another advantage of EACA is that it is much cheaper and safer than aprotinin.