Plötz F B, van Oeveren W, Bartlett R H, Wildevuur C R
Department of Pediatrics, Neonatology, University Hospital, Groningen, The Netherlands.
J Thorac Cardiovasc Surg. 1993 May;105(5):823-32.
Cardiopulmonary bypass for heart operations is associated with a whole body inflammatory reaction. The main factors involved in this reaction are the contact system and the complement system. The activation of the contact system is considered mainly responsible for impaired hemostasis because it affects platelet function. The activation of the complement system is considered the main cause for organ dysfunction, particularly of the lung, due to activation of leukocytes. This study in 10 neonates was undertaken to evaluate if there are effects of activation of the contact and the complement systems in neonatal extracorporeal life support comparable to those during cardiopulmonary bypass for cardiac operations. Two periods of blood activation during extracorporeal life support could be distinguished. The initial blood-material interaction at the onset of extracorporeal life support resulted in activation of both the contact and the complement systems. The contact activation was apparent by elevated factor XIIa-C1 esterase inhibitor complexes, decreased kallikrein inhibitory capacity, thrombin-antithrombin III formation, and moderate generation of fibrin(ogen) degradation products. The complement activation was characterized by elevated C3a, decreased leukocyte count, elastase release, and tumor necrosis factor-alpha production. This initial activation pattern subsided by 24 hours. A second activation period was observed 72 hours after the onset of extracorporeal life support, which was characterized only by increased clotting and fibrinolytic activity while no activation of the complement system was observed. We conclude that the initial activation pattern in extracorporeal life support is similar to that observed during cardiopulmonary bypass for cardiac operations. The contact activation that affects platelets might explain the continuous platelet consumption observed during extracorporeal life support. In this period, as in cardiopulmonary bypass, aprotinin given in the pump prime might be effective to prevent platelet consumption and impairment of hemostasis also in extracorporeal life support. The complement activation and leukocyte inflammatory reaction during the initial period are able to cause a capillary leak syndrome and might therefore explain the frequently observed temporary compromised lung function in extracorporeal life support. This reaction, as in cardiopulmonary bypass, might be reduced by the use of specific drugs or heparin coating also in extracorporeal life support. The cause of the second period of activation during extracorporeal life support requires further studies before adequate measures can be recommended.
心脏手术中的体外循环与全身炎症反应相关。参与该反应的主要因素是接触系统和补体系统。接触系统的激活主要被认为是导致止血功能受损的原因，因为它会影响血小板功能。补体系统的激活被认为是器官功能障碍的主要原因，尤其是肺部功能障碍，这是由于白细胞的激活所致。本研究对10名新生儿进行，旨在评估接触系统和补体系统的激活在新生儿体外生命支持中是否具有与心脏手术体外循环期间类似的影响。体外生命支持期间可区分出两个血液激活阶段。体外生命支持开始时最初的血液 - 材料相互作用导致接触系统和补体系统均被激活。接触系统激活表现为因子XIIa - C1酯酶抑制剂复合物升高、激肽释放酶抑制能力降低、凝血酶 - 抗凝血酶III形成以及纤维蛋白（原）降解产物适度生成。补体系统激活的特征是C3a升高、白细胞计数降低、弹性蛋白酶释放以及肿瘤坏死因子 - α产生。这种初始激活模式在24小时后消退。在体外生命支持开始72小时后观察到第二个激活阶段，其仅表现为凝血和纤溶活性增加，而未观察到补体系统激活。我们得出结论，体外生命支持中的初始激活模式与心脏手术体外循环期间观察到的模式相似。影响血小板的接触系统激活可能解释了体外生命支持期间持续的血小板消耗现象。在此阶段，如同在体外循环中一样，预充液中加入抑肽酶可能有效地防止血小板消耗以及止血功能受损，同样也适用于体外生命支持。初始阶段的补体系统激活和白细胞炎症反应能够导致毛细血管渗漏综合征，因此可能解释了体外生命支持中经常观察到的暂时性肺功能受损现象。如同在体外循环中一样，在体外生命支持中使用特定药物或肝素涂层也可能减轻这种反应。在推荐适当措施之前，体外生命支持期间第二个激活阶段的原因需要进一步研究。
