Outcomes after ultramassive transfusion in the modern era: An Eastern Association for the Surgery of Trauma multicenter study
Authors: Matthay Zachary A. , Hellmann Zane J. , Callcut Rachael A. , Matthay Ellicott C. , Nunez-Garcia Brenda , Duong William , Nahmias Jeffry , LaRiccia Aimee K. , Spalding M. Chance , Dalavayi Satya S. , Reynolds Jessica K. , Lesch Heather , Wong Yee M. , Chipman Amanda M. , Kozar Rosemary A. , Penaloza Liz , Mukherjee Kaushik , Taghlabi Khaled , Guidry Christopher A. , Seng Sirivan S. , Ratnasekera Asanthi , Motameni Amirreza , Udekwu Pascal , Madden Kathleen , Moore Sarah A. , Kirsch Jordan , Goddard Jesse , Haan James , Lightwine Kelly , Ontengco Julianne B. , Cullinane Daniel C. , Spitzer Sarabeth A. , Kubasiak John C. , Gish Joshua , Hazelton Joshua P. , Byskosh Alexandria Z. , Posluszny Joseph A. , Ross Erin E. , Park John J. , Robinson Brittany , Abel Mary Kathryn , Fields Alexander T. , Esensten Jonathan H. , Nambiar Ashok , Moore Joanne , Hardman Claire , Terse Pranaya , Luo-Owen Xian , Stiles Anquonette , Pearce Brenden , Tann Kimberly , Abdul Jawad Khaled , Ruiz Gabriel , Kornblith Lucy Z. 
Published: June 2021

BACKGROUND
Despite the widespread institution of modern massive transfusion protocols with balanced blood product ratios, survival for patients with traumatic hemorrhage receiving ultramassive transfusion (UMT) (defined as ≥20 U of packed red blood cells [RBCs]) in 24 hours) remains low and resource consumption remains high. Therefore, we aimed to identify factors associated with mortality in trauma patients receiving UMT in the modern resuscitation era.

METHODS
An Eastern Association for the Surgery of Trauma multicenter retrospective study of 461 trauma patients from 17 trauma centers who received ≥20 U of RBCs in 24 hours was performed (2014–2019). Multivariable logistic regression and Classification and Regression Tree analysis were used to identify clinical characteristics associated with mortality.

RESULTS
The 461 patients were young (median age, 35 years), male (82%), severely injured (median Injury Severity Score, 33), in shock (median shock index, 1.2; base excess, −9), and transfused a median of 29 U of RBCs, 22 U of fresh frozen plasma (FFP), and 24 U of platelets (PLT). Mortality was 46% at 24 hours and 65% at discharge. Transfusion of RBC/FFP ≥1.5:1 or RBC/PLT ≥1.5:1 was significantly associated with mortality, most pronounced for the 18% of patients who received both RBC/PLT and RBC/FFP ≥1.5:1 (odds ratios, 3.11 and 2.81 for mortality at 24 hours and discharge; both p < 0.01). Classification and Regression Tree identified that age older than 50 years, low initial Glasgow Coma Scale, thrombocytopenia, and resuscitative thoracotomy were associated with low likelihood of survival (14–26%), while absence of these factors was associated with the highest survival (71%).

CONCLUSION
Despite modern massive transfusion protocols, one half of trauma patients receiving UMT are transfused with either RBC/FFP or RBC/PLT in unbalanced ratios ≥1.5:1, with increased associated mortality. Maintaining focus on balanced ratios during UMT is critical, and consideration of advanced age, poor initial mental status, thrombocytopenia, and resuscitative thoracotomy can aid in prognostication.

LEVEL OF EVIDENCE
Prognostic, level III.