Department of Anesthesia, University of Toronto, Toronto, ON, Canada.
Hematology Am Soc Hematol Educ Program. 2018 Nov 30;2018(1):522-529. doi: 10.1182/asheducation-2018.1.522.
The use of extracorporeal circulation for cardiac surgery and extracorporeal life support poses tremendous challenges to the hemostatic equilibrium given its diametric tendency to trigger hyper- and hypocoagulopathy. The necessity of anticoagulant therapy to counteract the hemostatic activation by the extracorporeal circuitry compounded by unfavorable patient and surgical factors significantly increase the risk of catastrophic bleeding in patients who require extracorporeal circulation. Preoperative measures, such as stratification of high-risk bleeding patients, and optimization of the modifiable variables, including anemia and thrombocytopenia, provide a crude estimation of the likelihood and may modify the risk of catastrophic bleeding. The anticipation for catastrophic bleeding subsequently prompts the appropriate preparation for potential resuscitation and massive transfusion. Equally important is intraoperative prevention with the prophylactic application of tranexamic acid, an antifibrinolytic agent that has promising benefits in reduction of blood loss and transfusion. In the event of uncontrolled catastrophic bleeding despite preemptive strategies, all effort must be centered on regaining hemostasis through surgical control and damage control resuscitation to protect against worsening coagulopathy and end organ failure. When control of bleeding is reinstated, management should shift focus from systemic therapy to targeted hemostatic therapy aimed at the potential culprits of coagulopathy as identified by point of care hemostatic testing. This review article outlines the strategies to appropriately intervene using prediction, prevention, preparation, protection, and promotion of hemostasis in managing catastrophic bleeding in extracorporeal circulation.
体外循环在心脏手术和体外生命支持中的应用对止血平衡构成了巨大挑战,因为它有引发高凝和低凝状态的倾向。抗凝治疗的必要性是为了对抗体外循环引起的止血激活,加上不利的患者和手术因素,显著增加了需要体外循环的患者发生灾难性出血的风险。术前措施,如高危出血患者的分层,以及可改变变量的优化,包括贫血和血小板减少症,可以粗略估计发生灾难性出血的可能性,并可能改变灾难性出血的风险。对灾难性出血的预期随后促使为潜在复苏和大量输血做好适当的准备。同样重要的是术中预防,预防性应用氨甲环酸,一种抗纤维蛋白溶解剂,在减少出血和输血方面有很好的效果。尽管采取了预防策略,但如果发生无法控制的灾难性出血,所有努力都必须集中在通过手术控制和损伤控制性复苏来恢复止血,以防止凝血功能恶化和终末器官衰竭。一旦止血得到控制,管理应将重点从全身治疗转移到针对止血治疗,针对通过即时止血检测确定的凝血功能障碍的潜在罪魁祸首。这篇综述文章概述了在体外循环中管理灾难性出血时,通过预测、预防、准备、保护和促进止血来进行适当干预的策略。