Minimal effects of acute liver injury/acute liver failure on hemostasis as assessed by thromboelastography

Background & Aims: Patients with acute liver injury/failure (ALI/ALF) are assumed to have a bleeding diathesis on the basis of elevated INR; however, clinically significant bleeding is rare. We hypothesized that patients with ALI/ALF have normal hemostasis despite elevated INR. Methods: Fifty-one patients with ALI/ALF were studied prospectively using thromboelastography (TEG), which measures the dynamics and physical properties of clot formation in whole blood. ALI was defined as an INR >= 1.5 in a patient with no previous liver disease, and ALF as ALI with hepatic encephalopathy. Results: Thirty-seven of 51 patients (73%) had ALF and 22 patients (43%) underwent liver transplantation or died. Despite a mean INR of 3.4 +/- 1.7 (range 1.5-9.6), mean TEG parameters were normal, and 5 individual TEG parameters were normal in 32 (63%). Low maximum amplitude, the measure of ultimate clot strength, was confined to patients with platelet counts Conclusions: Despite elevated INR, most patients with ALI/ALF maintain normal hemostasis by TEG, the mechanisms of which include an increase in clot strength with increasing severity of liver injury, increased factor VIII levels, and a commensurate decline in pro-and anticoagulant proteins. (C) 2011 European Association for the Study of the Liver. Published by Elsevier B. V. All rights reserved