BACKGROUND:Low-titer group O whole blood (LTO-WB) has recently gained popularity in trauma centers for the acute resuscitation of hemorrhagic shock. However, limited supplies of Rh− product prevent implementation and strain sustainability at many trauma centers.We set out to identify whether Rh+ LTO-WB could be safely substituted for RH− product, regardless of patient's Rh status. METHODS:Following Institutional Review Board approval, information on all trauma patients receiving prehospital or emergency department transfusion of uncrossed, emergency release LTO-WB (11/17-10/19) were evaluated. Patients were first divided into those who received Rh− versus Rh+ product, the assessed by Rh of the recipient. Serial hemolysis panels, transfusion reactions, and outcomes were compared. RESULTS:Six hundred thirty-seven consecutive trauma patients received emergency release LTO-WB. Of these, 448 received Rh+ product, while 189 received Rh− LTO-WB. Patients receiving Rh+ product were more likely to be men (81 vs. 70%) and have lower field blood pressure (median 99 vs. 109) and GCS (median 7 vs. 12); all p < 0.05. There were no differences in blood product volume, hemolysis laboratories, transfusion reactions, complications, or survival. We then separated patients by Rh status (577 were Rh+, 70 were Rh−). Rh− patients were older (median age 54 vs. 39), more likely to be women (57 vs. 26%), and more likely to have sustained blunt trauma than their Rh+ counterparts (92 vs. 70%); all p < 0.05. There were no differences in hemolysis laboratories, transfusion reactions, complications, or survival between Rh+ and Rh− patients, regardless of Rh product received. CONCLUSION:When Rh− whole blood is unavailable or in short supply, Rh+ LTO-WB appears to be a safe alternative for the resuscitation of hemorrhagic shock in both Rh+ and Rh− patients. Use of Rh+ product may help trauma centers incorporate LTO-WB into their hospital and improve sustainability of such programs.

BACKGROUND: Whole blood was historically transfused as a type-specific product. Given recent advocacy for low-titer group O whole blood (LTOWB) as a universal blood product, we examined outcomes after LTOWB transfusion stratified by recipient blood groups. STUDY DESIGN: Adult trauma patients receiving prehospital or in-hospital transfusion of LTOWB (November 2017 to July 2020) at a single trauma center were prospectively evaluated. The patients were divided into blood type groups (O, A, B, and AB). Major complications and survival to 30 days were compared. Univariate analyses among blood groups were followed by purposeful regression modeling, reflecting 6 variables of significance: male sex, White race, injury severity, arrival lactate, arrival systolic blood pressure, and emergency department blood products. RESULTS: Of 1,075 patients receiving any LTOWB, 539 (50.1%) were Group O, 340 (31.6%) were Group A, 150 (14.0%) were Group B, and 46 (4.3%) were Group AB. There were no statistically significant differences in demographics, injury severity, hemolysis panels, prehospital vitals, or resuscitation parameters (all p > 0.05). However, arrival systolic pressure was lower (91 vs 102, p = 0.034) and lactate was worse (5.5 vs 4.1, p = 0.048) in Group B patients compared to other groups. While survival and most major complications did not differ across recipient groups, acute kidney injury (AKI) initially appeared higher for Group B. Stepwise regression did not show a difference in AKI rates. This analysis was repeated in patients receiving only component products. Group B again showed no significantly increased risk of AKI (13%) compared to other groups (O 7%, A 7%, AB 5%; p = 0.091). CONCLUSIONS: LTOWB appears to be a safe product for universal use across all blood groups. Group B recipients arrived with worse physiologic values associated with hemorrhagic shock whether receiving LTOWB or standard component products.

The TRPM4 gene codes for a membrane ion channel subunit related to inflammation in the central nervous system. Recent investigation has identified an association between TRPM4 single nucleotide polymorphisms (SNPs) rs8104571 and rs150391806 and increased intracranial (ICP) pressure following traumatic brain injury (TBI). We assessed the influence of these genotypes on clinical outcomes and ICP in TBI patients. We included 292 trauma patients with TBI. DNA extraction and real-time PCR were used for TRPM4 rs8104571 and rs150391806 allele discrimination. Five participants were determined to have the rs8104571 homozygous variant genotype, and 20 participants were identified as heterozygotes; 24 of these 25 participants were African American. No participants had rs150391806 variant alleles, preventing further analysis of this SNP. Genotypes containing the rs8104571 variant allele were associated with decreased Glasgow outcome scale-extended (GOSE) score (P = 0.0231), which was also consistent within our African-American subpopulation (P = 0.0324). Regression analysis identified an association between rs8104571 variant homozygotes and mortality within our overall population (P = 0.0230) and among African Americans (P = 0.0244). Participants with rs8104571 variant genotypes exhibited an overall increase in ICP (P = 0.0077), although a greater frequency of ICP measurements > 25 mmHg was observed in wild-type participants (P =  < 0.0001). We report an association between the TRPM4 rs8104571 variant allele and poor outcomes following TBI. These findings can potentially be translated into a precision medicine approach for African Americans following TBI utilizing TRPM4-specific pharmaceutical interventions. Validation through larger cohorts is warranted.