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.
Civilian guidelines for massive transfusion (MT ≥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.
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.
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 (≥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 (≥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.
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.
Transfusion practices and survival rates of massive transfusion (MT) patients vary widely among trauma centers. This study explored the effect of blood component ratios in MT, and found improved survival when plasma and platelet ratios were increased. We concluded that MT practice guidelines should aim for a 1:1:1 ratio of plasma, platelets, and red blood cells.
From the *United States Army Institute of Surgical Research, Ft Sam Houston, TX; †Department of Epidemiology and Biostatistics, University of Texas Health Science Center, San Antonio, TX; ‡Department of Trauma/Emergency and General Surgery Oregon Health and Science University, Portland, OR; §Department of Surgery, University of Texas Health Science Center, Houston, TX; ¶Department of Pathology, Wake Forest University School of Medicine, Winston Salem, NC; ∥Walter Reed Army Medical Center, Bethesda, MD; and **Connecticut Children's Medical Center, Hartford, CT.
The views and opinions expressed in this manuscript are those of the authors and do not reflect the official policy or position of the Army Medical Department, Department of the Army, the Department of Defense, or the United States Government.
Reprints: John B. Holcomb, MD, FACS, COL, MC, US Army, Commander, US Army Institute of Surgical Research, 3400 Rawley E, Chambers Avenue, Fort Sam Houston, TX 78234. E-mail: John.firstname.lastname@example.org.