title: Increased platelet:RBC ratios are associated with improved survival after massive transfusion.
abstract: BACKGROUND
  Several recent military and civilian trauma studies demonstrate that improved outcomes are associated with early and increased use of plasma-based resuscitation strategies. However, outcomes associated with platelet transfusions are poorly characterized. We hypothesized that increased platelet:red blood cells (RBC) ratios would decrease hemorrhagic death and improve survival after massive transfusion (MT).
  
  
  METHODS
  A transfusion database of patients transported from the scene to 22 Level I Trauma Centers over 12 months in 2005 to 2006 was reviewed. MT was defined as receiving ≥ 10 RBC units within 24 hours of admission. To mitigate survival bias, 25 patients who died within 60 minutes of arrival were excluded from analysis. Six random donor platelet units were considered equal to a single apheresis platelet unit. Admission and outcome data associated with the low (>1:20), medium (1:2), and high (1:1) platelet:RBC ratios were examined. These groups were based on the median value of the tertiles for the ratio of platelets:RBC units.
  
  
  RESULTS
  Two thousand three hundred twelve patients received at least one unit of blood and 643 received an MT. Admission vital signs, INR, temperature, pH, Glasgow Coma Scale, Injury Severity Score, and age were similar between platelet ratio groups. The average admission platelet counts were lower in the patients who received the high platelet:RBC ratio versus the low ratio (192 vs. 216, p = 0.03). Patients who received MT were severely injured, with a mean (± standard deviation) Injury Severity Score of 33 ± 16 and received 22 ± 15 RBCs and 11 ± 14 platelets within 24 hours of injury. Increased platelet ratios were associated with improved survival at 24 hours and 30 days (p < 0.001 for both). Truncal hemorrhage as a cause of death was decreased (low: 67%, medium: 60%, high: 47%, p = 0.04). Multiple organ failure mortality was increased (low: 7%, medium: 16%, high: 27%, p = 0.003), but overall 30-day survival was improved (low: 52%, medium: 57%, high: 70%) in the high ratio group (medium vs. high: p = 0.008; low vs. high: p = 0.007).
  
  
  CONCLUSIONS
  Similar to recently published military data, transfusion of platelet:RBC ratios of 1:1 was associated with improved early and late survival, decreased hemorrhagic death and a concomitant increase in multiple organ failure-related mortality. Based on this large retrospective study, increased and early use of platelets may be justified, pending the results of prospective randomized transfusion data.
authors.affiliation: Division of Acute Care Surgery, Center for Translational Injury Research, University of Texas Health Sciences Center, Houston, Texas 77030, USA. john.holcomb@uth.tmc.edu
authors.forename: John B
authors.initials: JB
authors.lastname: Holcomb
authors.forename: Lee A
authors.initials: LA
authors.lastname: Zarzabal
authors.forename: Joel E
authors.initials: JE
authors.lastname: Michalek
authors.forename: Rosemary A
authors.initials: RA
authors.lastname: Kozar
authors.forename: Phillip C
authors.initials: PC
authors.lastname: Spinella
authors.forename: Jeremy G
authors.initials: JG
authors.lastname: Perkins
authors.forename: Nena
authors.initials: N
authors.lastname: Matijevic
authors.forename: Jing-Fei
authors.initials: JF
authors.lastname: Dong
authors.forename: Shibani
authors.initials: S
authors.lastname: Pati
authors.forename: Charles E
authors.initials: CE
authors.lastname: Wade
authors.forename: J B
authors.initials: JB
authors.lastname: Holcomb
authors.forename: C E
authors.initials: CE
authors.lastname: Wade
authors.forename: B A
authors.initials: BA
authors.lastname: Cotton
authors.forename: R A
authors.initials: RA
authors.lastname: Kozar
authors.forename: K J
authors.initials: KJ
authors.lastname: Brasel
authors.forename: G A
authors.initials: GA
authors.lastname: Vercruysse
authors.forename: J B
authors.initials: JB
authors.lastname: MacLeod
authors.forename: R P
authors.initials: RP
authors.lastname: Dutton
authors.forename: J R
authors.initials: JR
authors.lastname: Hess
authors.forename: J C
authors.initials: JC
authors.lastname: Duchesne
authors.forename: N E
authors.initials: NE
authors.lastname: McSwain
authors.forename: P C
authors.initials: PC
authors.lastname: Muskat
authors.forename: J A
authors.initials: JA
authors.lastname: Johannigamn
authors.forename: H M
authors.initials: HM
authors.lastname: Cryer
authors.forename: A
authors.initials: A
authors.lastname: Tillou
authors.forename: M J
authors.initials: MJ
authors.lastname: Cohen
authors.forename: J F
authors.initials: JF
authors.lastname: Pittet
authors.forename: P
authors.initials: P
authors.lastname: Knudson
authors.forename: M A
authors.initials: MA
authors.lastname: DeMoya
authors.forename: M A
authors.initials: MA
authors.lastname: Schreiber
authors.forename: B H
authors.initials: BH
authors.lastname: Tieu
authors.forename: S I
authors.initials: SI
authors.lastname: Brundage
authors.forename: L M
authors.initials: LM
authors.lastname: Napolitano
authors.forename: M E
authors.initials: ME
authors.lastname: Brunsvold
authors.forename: K C
authors.initials: KC
authors.lastname: Sihler
authors.forename: G J
authors.initials: GJ
authors.lastname: Beilman
authors.forename: A B
authors.initials: AB
authors.lastname: Peitzman
authors.forename: M S
authors.initials: MS
authors.lastname: Zenati
authors.forename: J L
authors.initials: JL
authors.lastname: Sperry
authors.forename: L H
authors.initials: LH
authors.lastname: Alarcon
authors.forename: M A
authors.initials: MA
authors.lastname: Croce
authors.forename: J P
authors.initials: JP
authors.lastname: Minei
authors.forename: R M
authors.initials: RM
authors.lastname: Steward
authors.forename: S M
authors.initials: SM
authors.lastname: Cohn
authors.forename: J E
authors.initials: JE
authors.lastname: Michalek
authors.forename: E M
authors.initials: EM
authors.lastname: Bulger
authors.forename: T C
authors.initials: TC
authors.lastname: Nunez
authors.forename: R R
authors.initials: RR
authors.lastname: Ivatury
authors.forename: J W
authors.initials: JW
authors.lastname: Meredith
authors.forename: P R
authors.initials: PR
authors.lastname: Miller
authors.forename: G J
authors.initials: GJ
authors.lastname: Pomper
authors.forename: B
authors.initials: B
authors.lastname: Marin
mesh_terms: D000328:Adult; D001803:Blood Transfusion; D004636:Emergency Service, Hospital; D004906:Erythrocyte Count; D005260:Female; D006470:Hemorrhage / Q000097:blood* / Q000401:mortality / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome; D014947:Wounds and Injuries / Q000097:blood* / Q000401:mortality* / Q000628:therapy; D055815:Young Adult