Ahmad Mian, Mathew Johann, Iqbal Usama, Tariq Rayhan
Department of Anesthesiology and Perioperative Medicine, Drexel University College of Medicine, Hahnemann University Hospital, Philadelphia, PA 19102, USA.
Saudi J Anaesth. 2018 Jul-Sep;12(3):450-456. doi: 10.4103/sja.SJA_712_17.
Massive blood loss has been a dreaded complication of liver transplantation, and the accompanying transfusion is associated with adverse outcomes in the form of decreased patient and graft survival. With advances in both surgical techniques and anesthetic management during transplantation, blood and blood products requirements reduced significantly. However, transfusion practices vary among different centers. The altered coagulation parameters in patients with liver cirrhosis results in a state of "rebalanced hemostasis" and patients are just as likely to clot as they are to bleed. Commonly used coagulation tests do not always reflect this new state and can, therefore, be misleading. Transfusion of blood products solely to correct abnormal parameters may worsen the coagulation status, thus adversely affecting patient outcome. Point-of-care tests such as thromboelastometry more reliably predict the risk of bleeding in these patients and in addition may provide quicker turnaround times compared to routine tests. Perioperative management should also include the possibility of thrombosis in these patients, and the use of low-molecular-weight heparin correlates with better patient survival. This review article aims to highlight the concept of rebalanced hemostasis, limitation of routine coagulation tests, and harmful effect of empiric transfusion of blood products.
大量失血一直是肝移植令人恐惧的并发症,随之而来的输血会导致患者和移植物存活率降低等不良后果。随着移植手术技术和麻醉管理的进步,血液及血制品的需求量显著减少。然而,不同中心的输血操作各不相同。肝硬化患者凝血参数的改变导致一种“重新平衡的止血”状态,患者发生凝血和出血的可能性相同。常用的凝血检测并不总能反映这种新状态,因此可能会产生误导。单纯为纠正异常参数而输注血制品可能会使凝血状态恶化,从而对患者的预后产生不利影响。与常规检测相比,血栓弹力图等床旁检测能更可靠地预测这些患者的出血风险,并且周转时间可能更快。围手术期管理还应考虑这些患者发生血栓形成的可能性,使用低分子量肝素与患者更好的存活率相关。这篇综述文章旨在强调重新平衡的止血概念、常规凝血检测的局限性以及经验性输注血制品的有害影响。