title: Increased plasma and platelet to red blood cell ratios improves outcome in 466 massively transfused civilian trauma patients.
abstract: OBJECTIVE
  To determine the effect of blood component ratios in massive transfusion (MT), we hypothesized that increased use of plasma and platelet to red blood cell (RBC) ratios would result in decreased early hemorrhagic death and this benefit would be sustained over the ensuing hospitalization.
  
  
  BACKGROUND
  Civilian guidelines for massive transfusion (MT > or =10 units of RBC in 24 hours) have typically recommend a 1:3 ratio of plasma:RBC, whereas optimal platelet:RBC ratios are unknown. Conversely, military data shows that a plasma:RBC ratio approaching 1:1 improves long term outcomes in MT combat casualties. There is little consensus on optimal platelet transfusions in either civilian or military practice. At present, the optimal combinations of plasma, platelet, and RBCs for MT in civilian patients is unclear.
  
  
  METHODS
  Records of 467 MT trauma patients transported from the scene to 16 level 1 trauma centers between July 2005 and June 2006 were reviewed. One patient who died within 30 minutes of admission was excluded. Based on high and low plasma and platelet to RBC ratios, 4 groups were analyzed.
  
  
  RESULTS
  Among 466 MT patients, survival varied by center from 41% to 74%. Mean injury severity score varied by center from 22 to 40; the average of the center means was 33. The plasma:RBC ratio ranged from 0 to 2.89 (mean +/- SD: 0.56 +/- 0.35) and the platelets:RBC ratio ranged from 0 to 2.5 (0.55 +/- 0.50). Plasma and platelet to RBC ratios and injury severity score were predictors of death at 6 hours, 24 hours, and 30 days in multivariate logistic models. Thirty-day survival was increased in patients with high plasma:RBC ratio (> or =1:2) relative to those with low plasma:RBC ratio (<1:2) (low: 40.4% vs. high: 59.6%, P < 0.01). Similarly, 30-day survival was increased in patients with high platelet:RBC ratio (> or =1:2) relative to those with low platelet:RBC ratio (<1:2) (low: 40.1% vs. high: 59.9%, P < 0.01). The combination of high plasma and high platelet to RBC ratios were associated with decreased truncal hemorrhage, increased 6-hour, 24-hour, and 30-day survival, and increased intensive care unit, ventilator, and hospital-free days (P < 0.05), with no change in multiple organ failure deaths. Statistical modeling indicated that a clinical guideline with mean plasma:RBC ratio equal to 1:1 would encompass 98% of patients within the optimal 1:2 ratio.
  
  
  CONCLUSIONS
  Current transfusion practices and survival rates of MT patients vary widely among trauma centers. Conventional MT guidelines may underestimate the optimal plasma and platelet to RBC ratios. Survival in civilian MT patients is associated with increased plasma and platelet ratios. Massive transfusion practice guidelines should aim for a 1:1:1 ratio of plasma:platelets:RBCs.
authors.affiliation: United States Army Institute of Surgical Research, Ft Sam Houston, TX 78234, USA. John.holcomb@uth.tmc.edu
authors.forename: John B
authors.initials: JB
authors.lastname: Holcomb
authors.forename: Charles E
authors.initials: CE
authors.lastname: Wade
authors.forename: Joel E
authors.initials: JE
authors.lastname: Michalek
authors.forename: Gary B
authors.initials: GB
authors.lastname: Chisholm
authors.forename: Lee Ann
authors.initials: LA
authors.lastname: Zarzabal
authors.forename: Martin A
authors.initials: MA
authors.lastname: Schreiber
authors.forename: Ernest A
authors.initials: EA
authors.lastname: Gonzalez
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Pomper
authors.forename: Jeremy G
authors.initials: JG
authors.lastname: Perkins
authors.forename: Phillip C
authors.initials: PC
authors.lastname: Spinella
authors.forename: Kari L
authors.initials: KL
authors.lastname: Williams
authors.forename: Myung S
authors.initials: MS
authors.lastname: Park
mesh_terms: D000328:Adult; D016913:Blood Component Transfusion / Q000379:methods*; D017707:Erythrocyte Transfusion; D005260:Female; D006470:Hemorrhage / Q000209:etiology / Q000401:mortality* / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010949:Plasma; D017713:Platelet Transfusion; D012189:Retrospective Studies; D016019:Survival Analysis; D014193:Trauma Centers; D014947:Wounds and Injuries / Q000150:complications / Q000401:mortality* / Q000628:therapy*