Principles, Interpretation and Evidence-based Role of Viscoelastic Point-of-Care Coagulation Assays in Cirrhosis and Liver FailureAuthors

Abstract Standard coagulation tests (SCTs) like prothrombin time (PT), activated partial thromboplastin time and international normalized ratio (INR) are determined by liver-synthesized coagulation factors. Despite an increased INR, patients with cirrhosis are in a ‘rebalanced’ state of haemostasis as the concomitant effect of reduced protein C, protein S and thrombomodulin is not evaluated in SCTs. The cell-based model of hemostasis indicates additional mechanisms such as systemic inflammation, sepsis and organ failures tip the delicate coagulation balance to an anticoagulant type in acute-on-chronic liver failure (ACLF). In acute liver failure, thrombin generation and platelet function remain intact despite a marked prolongation in PT. Global coagulation tests provide a comprehensive estimate of coagulation in vitro; however, their use has only been validated in the setting of liver transplantation. In this review, we aim to explain the principles, application, and utility of viscoelastic (VE) tests like thromboelastography (TEG), rotational thromboelastometry (ROTEM), and Sonoclot. These point-of-care tests provide actionable targets for correcting the coagulation defect in a patient with bleeding and provide evidence-based algorithms for use in liver disease. A limitation of these tests is the inability to assess vessel injury and endothelial elements. Newer guidelines for hemostatic resuscitation are now accepting these POC tests, but additional data is required to validate their use as standard of care.