TOPLINE:

In a randomized trial, prehospital transfusion of whole blood did not reduce the risk for mortality or massive transfusion within 24 hours compared with standard component therapy in patients with major traumatic hemorrhage.

METHODOLOGY:

• Researchers conducted a pragmatic, phase 3, multicenter, unblinded, randomized superiority trial across 10 air ambulance services in England, including 942 patients with major traumatic hemorrhage (median age, 35-38 years; 74.5%-76.5% men) from 2022 to 2024, 71.3% of whom had sustained blunt trauma.
• Participants were randomly assigned to receive either whole blood transfusion (up to two units) or standard care with blood components (up to two units each of red cells and plasma) before arrival at the hospital.
• A total of 616 participants (314 in the whole blood group, and 302 in the standard care group) were included in an adjusted modified intention-to-treat analysis. The patients were followed up for 90 days.
• The primary outcome was a composite of death from any cause or receipt of a massive transfusion (at least 10 units of blood components or products in adults) within 24 hours after randomization. Secondary outcomes included all-cause death at 6 hours, 24 hours, 30 days, and 90 days; massive transfusion; days free from organ failure (up to 30 days); prothrombin time above the normal range; and thrombotic events within 30 days.

TAKEAWAY:

• The primary outcome occurred in 48.7% of participants in the whole blood group vs 47.7% of those in the standard care group (relative risk [RR], 1.02; P = .84).
• More patients in the whole blood group than in the standard care group had a prothrombin time above the normal range (40.7% vs 30.5%; RR, 1.31; 95% CI, 1.10-1.56).
• Serious adverse events were slightly more frequent in the standard care group than in the whole blood group (total number of events, 37 vs 31).
• The rate of thrombotic events within 30 days was similar between groups (RR, 0.89; 95% CI, 0.61-1.28), with no differences in all-cause mortality at any timepoint or in the rate of massive transfusion at 24 hours. 

IN PRACTICE:

"This trial provides key evidence to inform the use of whole blood within civilian prehospital trauma systems. Decisions about adopting the use of whole blood must balance logistic advantages against supply constraints, cost, and the overall availability of blood," the authors wrote.

SOURCE:

The study was led by Jason E. Smith, MD, Royal Centre for Defence Medicine, Birmingham, England. It was published online on March 17, 2026, in The New England Journal of Medicine.

LIMITATIONS:

The variability inherent to the prehospital environment and time-critical decision-making may have influenced treatment delivery and adherence to the protocol. The pragmatic design, which relied on clinical judgment to initiate transfusion, may have introduced population heterogeneity and led to the inclusion of some patients without life-threatening hemorrhage. The pragmatic trial design was dependent on the routine use of the Trauma Audit and Research Network database for injury characteristics, but a cyberattack on this database in 2023 resulted in missing data. 

DISCLOSURES:

This study received support from National Health Service (NHS) Blood and Transplant, the Ministry of Defence, and 10 Air Ambulance Charities including the Kent, Surrey, and Sussex Air Ambulance Trust. All blood components were provided by NHS Blood and Transplant. Some authors reported being employees of or affiliated with NHS Blood and Transplant or other transfusion services. Others reported being associated with academic institutions such as the University of Cambridge, University of Oxford, University of Exeter, and University of Warwick. One author reported having ties with organizations such as Elsevier, the British Heart Foundation, and GDP Consulting. Full details are provided in the original article.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.