title: Functional definition and characterization of acute traumatic coagulopathy.
abstract: OBJECTIVE
  To identify an appropriate diagnostic tool for the early diagnosis of acute traumatic coagulopathy and validate this modality through prediction of transfusion requirements in trauma hemorrhage.
  
  
  METHODS
  Prospective observational cohort study.
  
  
  METHODS
  Level 1 trauma center.
  
  
  METHODS
  Adult trauma patients who met the local criteria for full trauma team activation. Exclusion criteria included emergency department arrival >2 hrs after injury, >2000 mL of intravenous fluid before emergency department arrival, or transfer from another hospital.
  
  
  METHODS
  None.
  
  
  METHODS
  Blood was collected on arrival in the emergency department and analyzed with laboratory prothrombin time, point-of-care prothrombin time, and rotational thromboelastometry. Prothrombin time ratio was calculated and acute traumatic coagulopathy defined as laboratory prothrombin time ratio >1.2. Transfusion requirements were recorded for the first 12 hrs following admission.
  
  
  RESULTS
  Three hundred patients were included in the study. Laboratory prothrombin time results were available at a median of 78 (62-103) mins. Point-of-care prothrombin time ratio had reduced agreement with laboratory prothrombin time ratio in patients with acute traumatic coagulopathy, with 29% false-negative results. In acute traumatic coagulopathy, the rotational thromboelastometry clot amplitude at 5 mins was diminished by 42%, and this persisted throughout clot maturation. Rotational thromboelastometry clotting time was not significantly prolonged. Clot amplitude at a 5-min threshold of ≤35 mm had a detection rate of 77% for acute traumatic coagulopathy with a false-positive rate of 13%. Patients with clot amplitude at 5 mins ≤35 mm were more likely to receive red cell (46% vs. 17%, p < .001) and plasma (37% vs. 11%, p < .001) transfusions. The clot amplitude at 5 mins could identify patients who would require massive transfusion (detection rate of 71%, vs. 43% for prothrombin time ratio >1.2, p < .001).
  
  
  CONCLUSIONS
  In trauma hemorrhage, prothrombin time ratio is not rapidly available from the laboratory and point-of-care devices can be inaccurate. Acute traumatic coagulopathy is functionally characterized by a reduction in clot strength. With a threshold of clot amplitude at 5 mins of ≤35 mm, rotational thromboelastometry can identify acute traumatic coagulopathy at 5 mins and predict the need for massive transfusion.
authors.affiliation: Trauma Sciences, Blizard Institute of Cell and Molecular Science, Bart's and the London School of Medicine and Dentistry, Queen Mary University of London, UK.
authors.forename: Ross
authors.initials: R
authors.lastname: Davenport
authors.forename: Joanna
authors.initials: J
authors.lastname: Manson
authors.forename: Henry
authors.initials: H
authors.lastname: De'Ath
authors.forename: Sean
authors.initials: S
authors.lastname: Platton
authors.forename: Amy
authors.initials: A
authors.lastname: Coates
authors.forename: Shubha
authors.initials: S
authors.lastname: Allard
authors.forename: Daniel
authors.initials: D
authors.lastname: Hart
authors.forename: Rupert
authors.initials: R
authors.lastname: Pearse
authors.forename: K John
authors.initials: KJ
authors.lastname: Pasi
authors.forename: Peter
authors.initials: P
authors.lastname: MacCallum
authors.forename: Simon
authors.initials: S
authors.lastname: Stanworth
authors.forename: Karim
authors.initials: K
authors.lastname: Brohi
mesh_terms: D000208:Acute Disease; D000328:Adult; D001777:Blood Coagulation; D001778:Blood Coagulation Disorders / Q000175:diagnosis / Q000209:etiology*; D001780:Blood Coagulation Tests; D005260:Female; D006470:Hemorrhage / Q000097:blood / Q000150:complications; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011517:Prothrombin Time; D014947:Wounds and Injuries / Q000097:blood / Q000150:complications*; D055815:Young Adult