title: Fibrinolysis greater than 3% is the critical value for initiation of antifibrinolytic therapy.
abstract: BACKGROUND
  The acute coagulopathy of trauma is present in up to one third of patients by the time of admission, and the recent CRASH-2 and MATTERs trials have focused worldwide attention on hyperfibrinolysis as a component of acute coagulopathy of trauma. Thromboelastography (TEG) is a powerful tool for analyzing fibrinolyis, but a clinically relevant threshold for defining hyperfibrinolysis has yet to be determined. Recent data suggest that the accepted normal upper bound of 7.5% for 30-minute fibrinolysis (LY30) by TEG is inappropriate in severe trauma, as the risk of death rises at much lower levels of clot lysis. We wished to determine the validity of this hypothesis and establish a threshold value to treat fibrinolysis, based on prediction of massive transfusion requirement and risk of mortality.
  
  
  METHODS
  Patients with uncontrolled hemorrhage, meeting the massive transfusion protocol (MTP) criteria at admission (n = 73), represent the most severely injured trauma population at our center (median Injury Severity Score [ISS], 30; interquartile range, 20-38). Citrated kaolin TEG was performed at admission blood samples from this population, stratified by LY30, and evaluated for transfusion requirement and 28-day mortality. The same analysis was conducted on available field blood samples from all non-MTP trauma patients (n = 216) in the same period. These represent the general trauma population.
  
  
  RESULTS
  Within the MTP-activating population, the cohort of patients with LY30 of 3% or greater was shown to be at much higher risk for requiring a massive transfusion (90.9% vs. 30.5%, p = 0.0008) and dying of hemorrhage (45.5% vs. 4.8%, p = 0.0014) than those with LY30 less than 3%. Similar trends were seen in the general trauma population.
  
  
  CONCLUSIONS
  LY30 of 3% or greater defines clinically relevant hyperfibrinolysis and strongly predicts the requirement for massive transfusion and an increased risk of mortality in trauma patients presenting with uncontrolled hemorrhage. This threshold value for LY30 represents a critical indication for the treatment of fibrinolysis.
  
  
  METHODS
  Prognostic study, level III.
authors.affiliation: From the Department of Surgery (M.P.C., C.R.R., J.N.H., T.L.C., J.R.S., A.S., A.B.), University of Colorado-Denver; Denver Health Medical Center (M.P.C., E.E.M., C.R.R., A.G., J.N.H., T.L.C., J.R.S., A.S.); Medical College of Georgia (M.P.C.); and Bonfils Blood Center (C.C.S.), Denver, Colorado.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Chapman
authors.forename: Ernest E
authors.initials: EE
authors.lastname: Moore
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Ramos
authors.forename: Arsen
authors.initials: A
authors.lastname: Ghasabyan
authors.forename: Jeffrey N
authors.initials: JN
authors.lastname: Harr
authors.forename: Theresa L
authors.initials: TL
authors.lastname: Chin
authors.forename: John R
authors.initials: JR
authors.lastname: Stringham
authors.forename: Angela
authors.initials: A
authors.lastname: Sauaia
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Silliman
authors.forename: Anirban
authors.initials: A
authors.lastname: Banerjee
mesh_terms: D000328:Adult; D000933:Antifibrinolytic Agents / Q000008:administration & dosage*; D001778:Blood Coagulation Disorders / Q000097:blood* / Q000209:etiology / Q000628:therapy; D001803:Blood Transfusion; D004305:Dose-Response Relationship, Drug; D005260:Female; D005342:Fibrinolysis / Q000187:drug effects*; D005500:Follow-Up Studies; D006801:Humans; D015601:Injury Severity Score; D008297:Male; D011379:Prognosis; D012189:Retrospective Studies; D013916:Thrombelastography; D013997:Time Factors; D016896:Treatment Outcome; D014947:Wounds and Injuries / Q000097:blood / Q000150:complications*
chemical_list: D000933:Antifibrinolytic Agents