title: 1: 1 Transfusion strategies are right for the wrong reasons.
abstract: Early assessment of clot function identifies coagulopathies after injury. Abnormalities include a hypercoagulable state from excess thrombin generation, as well as an acquired coagulopathy. Efforts to address coagulopathy have resulted in earlier, aggressive use of plasma emphasizing 1:1 resuscitation. The purpose of this study was to describe coagulopathies in varying hemorrhagic profiles from a cohort of injured patients.
  
  
  
  All injured patients who received at least one unit of packed red blood cells (PRBC) in the first 24 hours of admission from September 2013 to May 2015 were eligible for inclusion. Group-Based Trajectory Modeling, using volume of transfusion over time, was used to identify specific hemorrhagic phenotypes. The thromboelastography profile of each subgroup was characterized and group features were compared.
  
  
  
  Four hemorrhagic profiles were identified among 330 patients-minimal (MIN, group 1); patients with large PRBC requirements later in the hospital course (LH, group 2); massive PRBC usage (MH, group 3), and PRBC transfusion limited to shortly after injury (EH, group 4). All groups had an R-time shorter than the normal range (3.2-3.5, p = NS). Patients in group 3 had longer K-times (1.8 vs. 1.2-1.3, p < 0.05), significantly flatter α-angles (66.7 vs. 70.4-72.8, p < 0.05), and significantly weaker clot strength (MA 54.6 vs. 62.3-63.6, p < 0.05). Group 3 had greater physiologic derangements at admission and worse overall outcomes.
  
  
  
  Hemorrhagic profiles suggest a rapid onset of clot formation in all subgroups but significantly suppressed thrombin burst and diminished clot strength in the most injured. Patients are both hypercoagulable, with early and precipitous clot formation, and also have a demonstrable hypocoagulability. The exact cause of traumatic hypocoagulability is likely multifactorial. Goal-directed resuscitation, as early as institution of the massive transfusion protocol, may be more effective in resuscitating the most coagulopathic patients.
  
  
  
  Prognostic study, level III.
authors.affiliation: From the Department of General Surgery (S.A.S., B.L.Z., B.L.B., T.H.P.), Indiana University School of Medicine, Indianapolis, Indiana; and Department of General Surgery (G.H.L., A.C.M., L.J.M., M.A.C.), University of Tennessee Health Sciences Center, Memphis, Tennessee.
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Savage
authors.forename: Ben L
authors.initials: BL
authors.lastname: Zarzaur
authors.forename: Brian L
authors.initials: BL
authors.lastname: Brewer
authors.forename: Garrett H
authors.initials: GH
authors.lastname: Lim
authors.forename: Ali C
authors.initials: AC
authors.lastname: Martin
authors.forename: Louis J
authors.initials: LJ
authors.lastname: Magnotti
authors.forename: Martin A
authors.initials: MA
authors.lastname: Croce
authors.forename: Timothy H
authors.initials: TH
authors.lastname: Pohlman
mesh_terms: D000328:Adult; D001778:Blood Coagulation Disorders / Q000209:etiology* / Q000628:therapy; D017707:Erythrocyte Transfusion / Q000379:methods*; D058734:Exsanguination / Q000150:complications / Q000628:therapy; D005260:Female; D006470:Hemorrhage / Q000150:complications* / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D012151:Resuscitation / Q000379:methods; D013916:Thrombelastography; D014947:Wounds and Injuries / Q000150:complications*