Stravitz R Todd
Dr. Stravitz is a Professor of Medicine and Medical Director of Liver Transplantation in the Section of Hepatology at the Hume-Lee Transplant Center of Virginia Commonwealth University in Richmond, Virginia.
Gastroenterol Hepatol (N Y). 2012 Aug;8(8):513-20.
Patients with acute and chronic liver disease have long been assumed to have a bleeding tendency on the basis of abnormal results for standard tests of hemostasis. However, recent studies have suggested that hemostasis in patients with liver disease exists in a state of rebalance, in which defects in prohemostatic drivers are compensated for by commensurate changes in antihemostatic drivers. Standard assays of hemostasis cannot evaluate this potential state of rebalance because they only assess components of clot formation and, therefore, may provide misleading information regarding the risk of bleeding, possibly leading clinicians to administer unneeded or even harmful prohemostatic factors. Thromboelastography (TEG) is a commercially available, rapid, point-of-care assay that assesses clot formation in whole blood, including plasmatic and cellular components. Studies using TEG in patients with cirrhosis and acute liver failure have suggested that rebalanced hemostasis exists in many patients, even in the presence of thrombocytopenia and an elevated prothrombin time/international normalized ratio. TEG has also been used to study mechanisms of rebalanced hemostasis and the pathogenesis of specific complications of liver disease, such as variceal rebleeding and infection. Finally, TEG has become widely used to guide factor repletion and fibrinolytic therapy during liver transplantation. The present clinical review will summarize these potential applications of TEG in patients with liver disease.
长期以来,急性和慢性肝病患者一直被认为因标准止血检测结果异常而具有出血倾向。然而,最近的研究表明,肝病患者的止血处于一种重新平衡的状态,其中促凝血驱动因素的缺陷会通过抗凝血驱动因素的相应变化得到补偿。标准的止血检测无法评估这种潜在的重新平衡状态,因为它们仅评估凝血形成的成分,因此可能会提供有关出血风险的误导性信息,可能导致临床医生给予不必要甚至有害的促凝血因子。血栓弹力图(TEG)是一种可商购的、快速的即时检测方法,可评估全血中的凝血形成,包括血浆和细胞成分。在肝硬化和急性肝衰竭患者中使用TEG的研究表明,即使存在血小板减少症和凝血酶原时间/国际标准化比值升高的情况,许多患者仍存在重新平衡的止血状态。TEG还被用于研究重新平衡止血的机制以及肝病特定并发症的发病机制,如静脉曲张再出血和感染。最后,TEG已广泛用于指导肝移植期间的因子补充和纤维蛋白溶解治疗。本临床综述将总结TEG在肝病患者中的这些潜在应用。