Mechanism Matters: Differential benefits of cold-stored whole blood for trauma resuscitation from a prospective multicenter study

BACKGROUND Resuscitation with cold-stored low-titre whole blood (LTOWB) has increased despite the paucity of robust civilian data. Most studies are in predominately blunt trauma and lack analysis of specific subgroups or mechanism of injury. We sought to compare outcomes between patients receiving LTOWB versus balanced component therapy (BCT) after blunt (BL) and penetrating (PN) trauma. METHODS Secondary analysis of a prospective multicenter study of patients receiving either LTWOB-containing or BCT resuscitation was performed. Patients were grouped by mechanism of injury (BL vs. PN). A generalized estimated equations model using inverse probability of treatment weighting was employed. Primary outcome was mortality and secondary outcomes were acute kidney injury, venous thromboembolism, pulmonary complications, and bleeding complications. Additional analyses were performed on no-traumatic brain injury (TBI), severe torso injury, and LTOWB-only resuscitation patients. RESULTS There were 1,617 patients (BL 47% vs PN 54%) identified; 1,175 (73%) of which received LTOWB. PN trauma patients receiving LTOWB demonstrated improved survival compared to BCT (77% vs. 56%; p < 0.01). Interval survival was higher at 6 hours (95% vs. 88%), 12 hours (93% vs. 80%), and 24 hours (88% vs. 57%) (all p < 0.05). The survival benefit following LTOWB was also seen across PN non-TBI (83% vs. 52%), and severe torso injuries (75% vs. 43%) (all p < 0.05). After controlling for age, sex, injury severity, and trauma center, LTWOB was associated with decreased odds of death (odds ratio, 0.31, p < 0.05) in PN trauma. However, no difference in overall mortality was seen across the BL groups. Both PN and BL patients receiving LTOWB had more frequent acute kidney injury compared to BCT (19% vs. 7% and 12% vs 6%, respectively; p < 0.05). CONCLUSION Low-titre whole blood resuscitation was independently associated with decreased mortality following PN trauma, but not BL trauma. Further analysis in BL trauma is required to identify subgroups that may demonstrate survival benefit. LEVEL OF EVIDENCE Therapeutic/Care Management; Level III.