BACKGROUND There is a resurgence in the use of low‐titer group O whole blood (LTOWB) for hemorrhagic shock. We hypothesized the use of LTOWB compared to component therapy (CT) would be independently associated with improved 24‐hour mortality. STUDY DESIGN AND METHODS In this prospective observational study, trauma patients 18 years of age or older with massive transfusion protocol activations were included from August 17, 2018, to May 14, 2019. The primary outcome was 24‐hour mortality. Secondary outcomes included 72‐hour blood product totals, multiple organ dysfunction scores (MODS), and 28‐day mortality. Multivariable logistic regression (MVLR) and Cox regression were performed to determine independent associations. RESULTS There were no clinically meaningful differences in measures of injury severity between study groups (CT, n = 42; LTOWB, n = 44). There was no difference in MODS between study groups. The unadjusted mortality was not statistically different between the study groups (9/42 [21%] for CT vs. 7/44 [16%] for LTOWB; p = 0.518). In the MVLR model, LTOWB increased the odds of 24‐hour survival by 23% (odds ratio 0.81, 95% confidence interval 0.69‐0.96; p = 0.017). Adjusted survival curve analysis indicated improved survival at both 24 hours and 28 days for LTOWB patients (p < 0.001). Further stratification showed an association between LTOWB use and survival when maximum clot firmness (MCF) was 60 mm or less (p = 0.009). CONCLUSIONS The use of LTOWB is independently associated with improved 24‐hour and 28‐day survival, and does not increase organ dysfunction at 72 hours. Use of LTOWB most impacted survival of patients with reduced clot firmness (MCF ≤60 mm). Collectively, these data support the clinical use and continued study of LTOWB for hemostatic resuscitation.

BACKGROUND The objective of this study was to assess transfusion strategies and outcomes, stratified by the combat mortality index, of casualties treated by small surgical teams in Afghanistan. Resuscitation that included warm fresh whole blood (FWB) was compared to blood component resuscitation. STUDY DESIGN AND METHODS Casualties treated by a Role 2 surgical team in Afghanistan from 2008 to 2014 who received 1 or more units of red blood cells (RBCs) or FWB were included. Patients were excluded if they had incomplete data or length of stay less than 30 minutes. Patients were separated into two groups: 1) received FWB and 2) did not receive FWB; moreover, both groups potentially received plasma, RBCs, and platelets. The analysis was stratified by critically versus noncritically injured patients using the prehospital combat mortality index. Kaplan‐Meier plot, log‐rank test, and multivariable Cox regression were performed to compare survival. RESULTS In FWB patients, median units of FWB and total blood product were 4.0 (interquartile range [IQR], 2.0‐7.0) and 16.0 (IQR, 10.0‐28.0), respectively. The Kaplan‐Meier plot demonstrated that survival was similar between FWB (79.1%) and no‐FWB (74.5%) groups (p = 0.46); after stratifying patients by the combat mortality index, the risk of mortality was increased in the no‐FWB group (hazard ratio, 2.8; 95% confidence interval, 1.2‐6.4) compared to the FWB cohort. CONCLUSION In forward‐deployed environments, where component products are limited, FWB has logistical advantages and was associated with reduced mortality in casualties with a critical combat mortality index. Additional analysis is needed to determine if these effects of FWB are appreciable in all trauma patients or just in those with severe physiologic derangement.

Background: Death from uncontrolled hemorrhage occurs rapidly, particularly among combat casualties. The US military has used warm fresh whole blood during combat operations owing to clinical and operational exigencies, but published outcomes data are limited. We compared early mortality between casualties who received warm fresh whole blood versus no warm fresh whole blood. Methods: Casualties injured in Afghanistan from 2008 to 2014 who received 2 red blood cell containing units were reviewed using records from the Joint Trauma System Role 2 Database. The primary outcome was 6-hour mortality. Patients who received red blood cells solely from component therapy were categorized as the nonewarm fresh whole blood group. None warm fresh whole blood patients were frequency-matched to warm fresh whole blood patients on identical strata by injury type, patient affiliation, tourniquet use, prehospital transfusion, and average hourly unit red blood cell transfusion rates, creating clinically unique strata. Multilevel mixed effects logistic regression adjusted for the matching, immortal time bias, and other covariates. Results: The 1,105 study patients (221 warm fresh whole blood, 884 nonewarm fresh whole blood) were classified into 29 unique clinical strata. The adjusted odds ratio of 6-hour mortality was 0.27 (95% confidence interval 0.13e0.58) for the warm fresh whole blood versus nonewarm fresh whole blood group. The reduction in mortality increased in magnitude (odds ratio ¼ 0.15, P ¼ .024) among the subgroup of 422 patients with complete data allowing adjustment for seven additional covariates. There was a dose-dependent effect of warm fresh whole blood, with patients receiving higher warm fresh whole blood dose (>33% of red blood cellecontaining units) having significantly lower mortality versus the nonewarm fresh whole blood group. Conclusion: Warm fresh whole blood resuscitation was associated with a significant reduction in 6-hour mortality versus nonewarm fresh whole blood in combat casualties, with a dose-dependent effect. These findings support warm fresh whole blood use for hemorrhage control as well as expanded study in military and civilian trauma settings.

Therapeutic/Care Management, level IV.