title: The ratio of fibrinogen to red cells transfused affects survival in casualties receiving massive transfusions at an army combat support hospital.
abstract: BACKGROUND
  To treat the coagulopathy of trauma, some have suggested early and aggressive use of cryoprecipitate as a source of fibrinogen. Our objective was to determine whether increased ratios of fibrinogen to red blood cells (RBCs) decreased mortality in combat casualties requiring massive transfusion.
  
  
  METHODS
  We performed a retrospective chart review of 252 patients at a U.S. Army combat support hospital who received a massive transfusion (>or=10 units of RBCs in 24 hours). The typical amount of fibrinogen within each blood product was used to calculate the fibrinogen-to-RBC (F:R) ratio transfused for each patient. Two groups of patients who received either a low (<0.2 g fibrinogen/RBC Unit) or high (>or=0.2 g fibrinogen/RBC Unit) F:R ratio were identified. Mortality rates and the cause of death were compared between these groups, and logistic regression was used to determine if the F:R ratio was independently associated with survival.
  
  
  RESULTS
  Two-hundred and fifty-two patients who received a massive transfusion with a mean (SD) ISS of 21 (+/-10) and an overall mortality of 75 of 252 (30%) were included. The mean (SD) F:R ratios transfused for the low and high groups were 0.1 grams/Unit (+/-0.06), and 0.48 grams/Unit (+/-0.2), respectively (p < 0.001). Mortality was 27 of 52 (52%) and 48 of 200 (24%) in the low and high F:R ratio groups respectively (p < 0.001). Additional variables associated with survival were admission temperature, systolic blood pressure, hemoglobin, International Normalized Ratio (INR), base deficit, platelet concentration and Combined Injury Severity Score (ISS). Upon logistic regression, the F:R ratio was independently associated with mortality (odds ratio 0.37, 95% confidence interval 0.171-0.812, p = 0.013). The incidence of death from hemorrhage was higher in the low F:R group, 23/27 (85%), compared to the high F:R group, 21/48 (44%) (p < 0.001).
  
  
  CONCLUSIONS
  In patients with combat-related trauma requiring massive transfusion, the transfusion of an increased fibrinogen: RBC ratio was independently associated with improved survival to hospital discharge, primarily by decreasing death from hemorrhage. Prospective studies are needed to evaluate the best source of fibrinogen and the optimal empiric ratio of fibrinogen to RBCs in patients requiring massive transfusion.
authors: Brooke Army Medical Center, U.S. Army Institute of Surgical Research, San Antonio, TX 78234-6200, USA. harry.stinger@us.army.mil
authors: Harry K
authors: HK
authors: Stinger
authors: Philip C
authors: PC
authors: Spinella
authors: Jeremy G
authors: JG
authors: Perkins
authors: Kurt W
authors: KW
authors: Grathwohl
authors: Jose
authors: J
authors: Salinas
authors: Wenjun Z
authors: WZ
authors: Martini
authors: John R
authors: JR
authors: Hess
authors: Michael A
authors: MA
authors: Dubick
authors: Clayton D
authors: CD
authors: Simon
authors: Alec C
authors: AC
authors: Beekley
authors: Steven E
authors: SE
authors: Wolf
authors: Charles E
authors: CE
authors: Wade
authors: John B
authors: JB
authors: Holcomb
mesh_terms: D015331:Cohort Studies; D004906:Erythrocyte Count; D017707:Erythrocyte Transfusion; D005340:Fibrinogen / Q000378:metabolism*; D006772:Hospitals, Military; D006801:Humans; D015601:Injury Severity Score; D054542:Iraq War, 2003-2011; D012372:ROC Curve; D012189:Retrospective Studies; D015996:Survival Rate; D014481:United States; D014947:Wounds and Injuries / Q000097:blood* / Q000401:mortality* / Q000628:therapy
chemical_list: D005340:Fibrinogen