Topic: B. Clinical Burns/Trauma
Increased Plasma and Platelet to RBC Ratios Improves Outcome in 466 Massively Transfused Civilian Trauma Patients
John B Holcomb1, Charles E Wade1, Joel E Michalek2, Gary B Chisholm2, Martin A Schreiber3, Ernest A Gonzalez4, Greg Pomper5, Kari L Williams1, Myung S Park1, and The Trauma Outcomes Group6
1US Army Institute of Surgical Research, Ft Sam Houston, TX;2University of Texas Health Science Center, San Antonio, TX;3Oregon Health and Science University, Portland, OR;4University of Texas Health Science Center, Houston, TX;5Wake Forrest School of Medicine, Winston Salem, NC;6Trauma Outcomes Group, Ft Sam Houston, TX
OBJECTIVE: Civilian massive transfusion (MT≥10 units of RBC) guidelines frequently recommend a 1:4 ratio of plasma:RBC. Conversely, military data show that 1:1 plasma:RBC ratios improve outcomes in MT combat casualties. Optimal relationships of plasma and platelet to RBC ratios in MT civilian patients are unknown.
METHODS: Records of 466 MT trauma patients treated at 16 major Level 1 trauma centers between July 2005 and June 2006 were reviewed.
RESULTS: Survival varied by center from 41% to 74%. The Injury Severity Score, (ISS, mean ± SD) varied by center from 22 to 40 (32±16). The mean plasma:RBC ratio varied by center from 0.32 to 0.87 while the platelets:RBC ratio varied from 0.10 to 1.06. For individual patients the plasma:RBC ratio ranged from 0 to 2.89 and the platelets:RBC ratio ranged from 0 to 2.5. Plasma and platelet to RBC ratios and ISS were independent predictors of death at 30 days. Any plasma:RBC ratio > 1:2 improved 30 day survival, (61% vs 53%, p<0.01). Similarly, a platelet:RBC ratio >1:2 improved 30 day survival (70% vs 44%, p<0.01). Given the distribution of plasma:RBC ratios, a statistical model was created to encompass 98% of patients within the optimal ratio of 1:2. The model indicated a clinical guideline of 1:1 would be optimal.
CONCLUSIONS: Conventional MT practices vary widely at Level 1 Trauma centers, while survival after massive transfusion differs greatly. Survival in MT civilian patients is improved by increasing plasma and platelet ratios. Prospective trials should aim for a 1:1 ratio of plasma; RBC.