Acute Liver Failure: Managing Coagulopathy and the Bleeding Diathesis

Acute liver failure (ALF) is defined as a severe, sudden liver dysfunction that induces encephalopathy and coagulopathy (prothrombin time [PT/INR] > 1.5) within 26 weeks of the onset of symptoms (usually jaundice) in patients without previous liver disease. Quantitative and qualitative platelet dysfunction, reduced synthesis of clotting factors, increased consumption of factors (mainly II, V, VII, X), reduced clearance of both activated factors, and/or factor inhibitor complexes are among the most important proposed pathogenetic factors. A possible role might be also played by the diminished degradation of anticoagulants. Plasminogen activator inhibitor 1 (PAI-1) is increased, shifting the balance toward hypofibrinolysis, despite the elevated levels of tissue plasminogen activator (tPA). Although changes in coagulation parameters provide crucial information for the management of the patient with ALF, the optimal management of the hemostatic defects is far from being defined. Because spontaneous bleeding occurs rarely during ALF, measures to improve the bleeding diathesis (fresh frozen plasma, cryoprecipitate, platelet transfusion) are recommended only in patients with clinically significant bleeding or before placement of invasive devices. Antifibrinolytic drugs are used in some cases, but often empirically. The role of rFVIIa, even if promising, is still under debate.