title: Definition and drivers of acute traumatic coagulopathy: clinical and experimental investigations.
abstract: BACKGROUND
  Acute traumatic coagulopathy (ATC) is an impairment of hemostasis that occurs early after injury and is associated with a 4-fold higher mortality, increased transfusion requirements and organ failure.
  
  
  OBJECTIVE
  The purpose of the present study was to develop a clinically relevant definition of ATC and understand the etiology of this endogenous coagulopathy.
  
  
  METHODS
  We conducted a retrospective cohort study of trauma patients admitted to five international trauma centers and corroborated our findings in a novel rat model of ATC. Coagulation status on emergency department arrival was correlated with trauma and shock severity, mortality and transfusion requirements. 3646 complete records were available for analysis.
  
  
  RESULTS
  Patients arriving with a prothrombin time ratio (PTr) > 1.2 had significantly higher mortality and transfusion requirements than patients with a normal PTr (mortality: 22.7% vs. 7.0%; P < 0.001. Packed red blood cells: 3.5 vs. 1.2 units; P < 0.001. Fresh frozen plasma: 2.1 vs. 0.8 units; P < 0.001). The severity of ATC correlated strongly with the combined degree of injury and shock. The rat model controlled for exogenously induced coagulopathy and mirrored the clinical findings. Significant coagulopathy developed only in animals subjected to both trauma and hemorrhagic shock (PTr: 1.30. APTTr: 1.36; both P < 0.001 compared with sham controls).
  
  
  CONCLUSIONS
  ATC develops endogenously in response to a combination of tissue damage and shock. It is associated with increased mortality and transfusion requirements in a dose-dependent manner. When defined by standard clotting times, a PTr > 1.2 should be adopted as a clinically relevant definition of ATC.
authors.affiliation: Trauma Clinical Academic Unit, The Royal London Hospital, Bart's & The London School of Medicine & Dentistry, Queen Mary University London, UK.
authors.forename: D
authors.initials: D
authors.lastname: Frith
authors.forename: J C
authors.initials: JC
authors.lastname: Goslings
authors.forename: C
authors.initials: C
authors.lastname: Gaarder
authors.forename: M
authors.initials: M
authors.lastname: Maegele
authors.forename: M J
authors.initials: MJ
authors.lastname: Cohen
authors.forename: S
authors.initials: S
authors.lastname: Allard
authors.forename: P I
authors.initials: PI
authors.lastname: Johansson
authors.forename: S
authors.initials: S
authors.lastname: Stanworth
authors.forename: C
authors.initials: C
authors.lastname: Thiemermann
authors.forename: K
authors.initials: K
authors.lastname: Brohi
mesh_terms: D000328:Adult; D000818:Animals; D001777:Blood Coagulation; D001778:Blood Coagulation Disorders / Q000209:etiology*; D001803:Blood Transfusion / Q000379:methods; D015331:Cohort Studies; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D051381:Rats; D012189:Retrospective Studies; D012771:Shock, Hemorrhagic / Q000175:diagnosis; D014947:Wounds and Injuries / Q000150:complications*