Coagulopathy, Bleeding Events and Outcome According to Rotational Thromboelastometry in Patients with Acute Liver Injury/Failure.

BACKGROUND & AIMS Patients with acute liver injury or failure (ALI/ALF) experience bleeding complications uncommonly despite an abnormal hemostatic profile. Rotational thromboelastometry (ROTEM), which assesses clot formation in whole blood, was employed to determine the nature of abnormal hemostasis and whether it contributes to bleeding events, illness severity, or survival. APPROACH & RESULTS 200 patients were recruited from sites of the ALF Study Group. Blood collected daily for up to 5 days was analyzed using ROTEM delta® devices. Consistent with standard laboratory evidence of hypocoagulability (median INR 2.9 and platelet count 144x109 /L), patients frequently exhibited ROTEM parameters outside normal-range (73% and 62% had abnormalities in clot formation from extrinsic and intrinsic clotting cascades, respectively); however, measures of clot stability were generally normal. Eighteen patients (9%) experienced bleeding events, in whom clot initiation, assembly, and firmness were more severely deranged than patients without bleeding. Abnormal ROTEM parameters were more frequently observed in patients with non-acetaminophen (APAP) ALI/ALF than those with APAP ALI/ALF (clot initiation (P<0.001), assembly (P=0.02), firmness at 10 min (P=0.05), and maximal firmness (P=0.06)). Patients with more severe systemic complications (high-grade hepatic encephalopathy and need for renal replacement therapy) also had a higher incidence of abnormal ROTEM parameters. Finally, more hypocoagulable ROTEM parameters (clot initiation (P=0.005), stiffness at 10 min (P=0.05), and maximal stiffness by fibrin assembly (P=0.004)) were observed in patients who died or underwent liver transplantation than those who survived with their native liver. CONCLUSIONS In patients with ALI/ALF, abnormal ROTEM parameters are frequent and proportional to disease severity. Whether the increased bleeding risk associated with abnormal ROTEM indicates hemostatic failure or is a proxy for disease severity requires additional study.