title: Minimal effects of acute liver injury/acute liver failure on hemostasis as assessed by thromboelastography.
abstract: OBJECTIVE
  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 <126×10(9)/L. Maximum amplitude was higher in patients with ALF than ALI and correlated directly with venous ammonia concentrations and with increasing severity of liver injury assessed by elements of the systemic inflammatory response syndrome. All patients had markedly decreased procoagulant factor V and VII levels, which were proportional to decreases in anticoagulant proteins and inversely proportional to elevated factor VIII levels.
  
  
  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.
authors.affiliation: Section of Hepatology and Hume-Lee Transplant Center, Virginia Commonwealth University, Richmond, VA 23298-0341, USA. rstravit@vcu.edu
authors.forename: R Todd
authors.initials: RT
authors.lastname: Stravitz
authors.forename: Ton
authors.initials: T
authors.lastname: Lisman
authors.forename: Velimir A
authors.initials: VA
authors.lastname: Luketic
authors.forename: Richard K
authors.initials: RK
authors.lastname: Sterling
authors.forename: Puneet
authors.initials: P
authors.lastname: Puri
authors.forename: Michael
authors.initials: M
authors.lastname: Fuchs
authors.forename: Ashraf
authors.initials: A
authors.lastname: Ibrahim
authors.forename: William M
authors.initials: WM
authors.lastname: Lee
authors.forename: Arun J
authors.initials: AJ
authors.lastname: Sanyal
mesh_terms: D000328:Adult; D001779:Blood Coagulation Factors / Q000378:metabolism; D056486:Chemical and Drug Induced Liver Injury / Q000097:blood / Q000150:complications / Q000209:etiology; D005260:Female; D006487:Hemostasis; D006801:Humans; D008099:Liver / Q000293:injuries*; D017114:Liver Failure, Acute / Q000097:blood* / Q000150:complications / Q000209:etiology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D013916:Thrombelastography
chemical_list: D001779:Blood Coagulation Factors