Malviya S
Department of Anesthesiology, University of Michigan Health Systems, Ann Arbor 48109-0211, USA.
Semin Thromb Hemost. 1997;23(6):563-7. doi: 10.1055/s-2007-996137.
Pharmacologic manipulation of hemostasis is a prerequisite for cardiac surgery with cardiopulmonary bypass (CPB) to prevent clot formation in the extracorporeal circuit. Children who require surgical correction of congenital heart defects are at increased risk for prolonged and excessive bleeding after separation from CPB. Heparin remains the anticoagulant of choice for surgery requiring CPB. Traditional regimens of empiric heparin dosing and a fixed-dose ratio of protamine to heparin for reversal of anticoagulation do not account for individual differences in the half-life of heparin, clearance of heparin, and duration of CPB, particularly in children. In addition, the use of prolongation of the activated clotting time (ACT) as a measure of adequate anticoagulation does not account for alterations in ACT by factors unrelated to heparin activity, including hemodilution and hypothermia, that are frequently present during CPB. This manuscript reviews the pitfalls in the management of anticoagulation for children undergoing surgery that requires CPB. Pertinent literature related to the use of aprotinin, a serine protease inhibitor that has been shown to improve hemostasis during and after CPB, is discussed. It is hoped that this article will provide a practical guideline for the rational management of anticoagulation in children with congenital heart disease undergoing CPB surgery.
对止血进行药理调控是体外循环心脏手术预防体外循环回路中血栓形成的前提条件。需要对先天性心脏缺陷进行手术矫正的儿童在脱离体外循环后发生出血时间延长和出血过多的风险增加。肝素仍然是需要体外循环手术时的抗凝剂首选。传统的经验性肝素给药方案以及用于逆转抗凝作用的鱼精蛋白与肝素的固定剂量比没有考虑到肝素半衰期、肝素清除率和体外循环持续时间的个体差异，尤其是在儿童中。此外，使用活化凝血时间（ACT）延长作为充分抗凝的指标并未考虑到与肝素活性无关的因素（包括血液稀释和低温）对ACT的影响，而这些因素在体外循环期间经常存在。本文综述了需要体外循环手术的儿童抗凝管理中的陷阱。讨论了与使用抑肽酶相关的相关文献，抑肽酶是一种丝氨酸蛋白酶抑制剂，已被证明可改善体外循环期间及之后的止血情况。希望本文能为先天性心脏病患儿接受体外循环手术时抗凝的合理管理提供实用指南。
