title: Hyperfibrinolysis, physiologic fibrinolysis, and fibrinolysis shutdown: the spectrum of postinjury fibrinolysis and relevance to antifibrinolytic therapy.
abstract: BACKGROUND
  Fibrinolysis is a physiologic process maintaining patency of the microvasculature. Maladaptive overactivation of this essential function (hyperfibrinolysis) is proposed as a pathologic mechanism of trauma-induced coagulopathy. Conversely, the shutdown of fibrinolysis has also been observed as a pathologic phenomenon. We hypothesize that there is a level of fibrinolysis between these two extremes that have a survival benefit for the severely injured patients.
  
  
  METHODS
  Thrombelastography and clinical data were prospectively collected on trauma patients admitted to our Level I trauma center from 2010 to 2013. Patients with an Injury Severity Score (ISS) of 15 or greater were evaluated. The percentage of fibrinolysis at 30 minutes by thrombelastography was used to stratify three groups as follows: hyperfibrinolysis (≥3%), physiologic (0.081-2.9%), and shutdown (0-0.08%). The threshold for hyperfibrinolysis was based on existing literature. The remaining groups were established on a cutoff of 0.8%, determined by the highest point of specificity and sensitivity for mortality on a receiver operating characteristic curve.
  
  
  RESULTS
  One hundred eighty patients were included in the study. The median age was 42 years (interquartile range [IQR], 28-55 years), 70% were male, and 21% had penetrating injuries. The median ISS was 29 (IQR, 22-36), and the median base deficit was 9 mEq/L (IQR, 6-13 mEq/L). Distribution of fibrinolysis was as follows: shutdown, 64% (115 of 180); physiologic, 18% (32 of 180); and hyperfibrinolysis, 18% (33 of 180). Mortality rates were lower for the physiologic group (3%) compared with the hyperfibrinolysis (44%) and shutdown (17%) groups (p = 0.001).
  
  
  CONCLUSIONS
  We have identified a U-shaped distribution of death related to the fibrinolysis system in response to major trauma, with a nadir in mortality, with level of fibrinolysis after 30 minutes between 0.81% and 2.9%. Exogenous inhibition of the fibrinolysis system in severely injured patients requires careful selection, as it may have an adverse affect on survival.
  
  
  METHODS
  Prognostic study, level III.
authors: From the Departments of Surgery (H.B.M., E.E.M., E.G., M.P.C., T.L.C., A.B., A.S.) and Pediatrics (C.C.S.), University of Colorado Denver; Department of Surgery (E.E.M.), Denver Health Medical Center; and Bonfils Blood Center (C.C.S.), Denver, Colorado.
authors: Hunter B
authors: HB
authors: Moore
authors: Ernest E
authors: EE
authors: Moore
authors: Eduardo
authors: E
authors: Gonzalez
authors: Michael P
authors: MP
authors: Chapman
authors: Theresa L
authors: TL
authors: Chin
authors: Christopher C
authors: CC
authors: Silliman
authors: Anirban
authors: A
authors: Banerjee
authors: Angela
authors: A
authors: Sauaia
mesh_terms: D000328:Adult; D005260:Female; D005342:Fibrinolysis / Q000502:physiology*; D006801:Humans; D015601:Injury Severity Score; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013916:Thrombelastography; D014947:Wounds and Injuries / Q000401:mortality / Q000473:pathology / Q000503:physiopathology*