title: Plasma-to-red cell ratio and mechanism of injury in massively transfused combat casualties.
abstract: METHODS
  A retrospective review of 930 combat casualties from March 2003 to September 2009 who received a massive transfusion. Mechanism was categorized as explosion (EXPL) (712), gunshot wound (GSW) (190), and blunt trauma (28). Cohorts were also categorized by fresh frozen plasma (FFP) to red blood cell (RBC) ratio: low, ≤1:1.5 and high, >1:1.5. Patient characteristics and in-hospital mortality rates were compared among groups. Propensity matching was used to control for confounding variables.
  
  
  RESULTS
  Cohorts were similar in demographics, admission vital signs, and laboratory values. Median injury severity score was higher in EXPL compared to GSW. High FFP:RBC ratio was associated with improved survival compared to low ratio in the EXPL group (p < 0.01). The GSW group had similar survival in the high and low FFP:RBC ratio groups (p = 0.06). After propensity matching, a high FFP:RBC ratio was associated with improved survival compared to low ratio in both the EXPL (p < 0.01) and GSW groups (p = 0.05).
  
  
  CONCLUSIONS
  High FFP:RBC ratios are associated with improved survival in combat casualties regardless of injury mechanism.
authors.affiliation: The United States Army Institute of Surgical Research, 3400 Rawley Chambers Avenue, Fort Sam Houston, TX 78234.
authors.forename: Mark O
authors.initials: MO
authors.lastname: Hardin
authors.affiliation: The United States Army Institute of Surgical Research, 3400 Rawley Chambers Avenue, Fort Sam Houston, TX 78234.
authors.forename: John D
authors.initials: JD
authors.lastname: Ritchie
authors.affiliation: The United States Army Institute of Surgical Research, 3400 Rawley Chambers Avenue, Fort Sam Houston, TX 78234.
authors.forename: James K
authors.initials: JK
authors.lastname: Aden
authors.affiliation: The United States Army Institute of Surgical Research, 3400 Rawley Chambers Avenue, Fort Sam Houston, TX 78234.
authors.forename: Lorne H
authors.initials: LH
authors.lastname: Blackbourne
authors.affiliation: Department of General Surgery, 3851 Roger Brooke Drive, Fort Sam Houston, TX 78234-6315.
authors.forename: Christopher E
authors.initials: CE
authors.lastname: White
mesh_terms: D000328:Adult; D055826:Afghan Campaign 2001-; D001753:Blast Injuries / Q000097:blood* / Q000628:therapy; D001803:Blood Transfusion / Q000379:methods*; D004912:Erythrocytes; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D054542:Iraq War, 2003-2011; D008297:Male; D008889:Military Personnel; D010949:Plasma; D012189:Retrospective Studies; D015996:Survival Rate; D015599:Trauma Severity Indices; D014481:United States; D014948:Wounds, Gunshot / Q000097:blood* / Q000628:therapy; D014949:Wounds, Nonpenetrating / Q000097:blood* / Q000628:therapy; D055815:Young Adult