Blood in EMS Part 1

Why Proximity to the ED Is Only Part of the Decision

Prehospital blood deserves an evaluation based on patient need, the treatment interval and the ability to deliver a safe transfusion program. [1]

“We are close to the emergency department.” It is a common starting point in discussions about whether EMS should carry blood. It should lead to a closer examination of the patient’s pathway to treatment.

I am in favor of well-governed prehospital blood programs for patients with life-threatening hemorrhage. Hospital proximity, by itself, does not answer whether an appropriate patient could receive needed resuscitation sooner.

The clinical case is strong enough to deserve serious consideration. The evidence also requires precision: a survival benefit has been demonstrated in some settings, while other randomized trials have not shown improvement. Short transport times matter, and whole blood has not been proved superior to component therapy in the major prehospital trials published in 2026. [4] [5] [7] [8] [9]

The useful question is: Can this system bring appropriate blood resuscitation forward safely, while preserving rapid access to definitive bleeding control? That is the question this three-part series will explore.

Hemorrhagic shock requires more than fluid volume

Severe blood loss creates several problems at once. Circulating volume falls, oxygen delivery is threatened, and effective clot formation may be impaired. A resuscitation strategy must address the bleeding as well as the consequences of that loss. [1]

Red cells carry oxygen. Plasma supplies coagulation factors, and platelets help form a clot. Whole blood contains those components together. Crystalloid fluids do not provide red cells, platelets or coagulation factors. These differences explain the physiological appeal of blood-based resuscitation; they do not, alone, establish a survival advantage for every patient or every delivery model. [2]

The 2025 NAEMSP position statement recommends blood components over crystalloids as first-line resuscitation for traumatic life-threatening bleeding in EMS systems able to support a high-quality transfusion program. Its recommendation links clinical capability with the ability to deliver it safely. [1]

For EMS leaders, this is a reason to evaluate blood as part of hemorrhage care, alongside prompt bleeding control and appropriate transport.

Blood resuscitation belongs alongside bleeding control and rapid access to definitive care. This image is an illustration, not a clinical case photograph. [3]

Being close to the ED needs a measured care pathway

Driving time answers how long a journey may take. It does not automatically establish the interval from the patient’s injury or recognition of shock to the first transfusion. EMS and hospital leaders should examine that entire pathway.

How much scene time is necessary? Is extrication required? When can a blood-equipped resource reach the patient? Is the receiving ED ready to begin transfusion immediately? Could earlier notification shorten the interval? Would preparing a prehospital transfusion add avoidable delay to departure? These are local questions to measure, rather than assumptions about every hospital or ambulance service.

My system-design recommendation is to review timestamps for patient contact, recognition of a transfusion indication, departure, hospital arrival and actual transfusion start. Where reliable injury-time information exists, include it. Examine the cases individually before drawing conclusions from averages.

A short drive may coexist with a longer period before blood reaches the patient. Conversely, a nearby, prepared trauma center may offer a very short interval to transfusion and definitive care. Both circumstances belong in the decision. An agency should be able to demonstrate what its proposed blood program would change.

This is a planning framework, not a claim that a particular number of minutes guarantees benefit. The patient’s physiology, the bleeding, the actual treatment interval and the safety of the delivery model must be considered together.

A nearby ED is one part of the pathway. Reviewing actual time to first transfusion is a proposed local quality-improvement approach, not a universal treatment threshold.

Read the trials before repeating the headline

Prehospital transfusion studies ask different questions. Some compare plasma or other blood products with fluid-based resuscitation. Others compare whole blood with blood components already being administered before hospital arrival. Their results should be interpreted within those comparisons.

PAMPer found a survival benefit during air medical transport

PAMPer evaluated 501 injured patients at risk for hemorrhagic shock. Thirty-day mortality was 23.2% with prehospital plasma and 33.0% with standard-care resuscitation, an absolute difference of 9.8 percentage points. This is important randomized evidence supporting earlier plasma in the population and air medical setting studied. It was a plasma trial, so it does not prove that whole blood is superior or that the same benefit occurs in every ground EMS system. [4]

COMBAT did not show a survival benefit in rapid urban ground transport

COMBAT examined plasma-first resuscitation during urban ground transport to a mature trauma center. Its as-treated analysis included 125 eligible patients. It did not demonstrate improved 28-day survival with plasma compared with saline. An argument for EMS blood has to acknowledge this result, particularly when discussing systems with rapid access to hospital transfusion. [5]

RePHILL did not improve its primary composite outcome

The UK RePHILL trial randomized 432 patients with trauma-related hemorrhagic shock to packed red cells plus lyophilized plasma or saline. It did not show superiority for its primary composite outcome of episode mortality or impaired lactate clearance. Its authors called for further work to identify the patients who may benefit. The result limits claims of a universal advantage for prehospital blood over saline across all studied settings. [7]

SWiFT compared whole blood with blood components

Published in 2026, SWiFT compared up to two units of whole blood with prehospital red cells and plasma across ten air ambulance services in England. Whole blood did not show superiority for the primary outcome of death or massive transfusion within 24 hours. Both groups had access to prehospital blood products; the trial did not compare carrying blood with carrying none. [8]

TOWAR also compared two transfusion strategies

The 2026 TOWAR trial compared prehospital whole blood with red cells, plasma or both at 44 air medical bases. Whole blood did not produce lower 30-day mortality. The rates were 25.9% and 20.5%, respectively, with no statistically significant difference. A failure to demonstrate superiority is not proof that the strategies are identical. It is also not a test of prehospital blood against no prehospital transfusion. [9]

These studies support an informed discussion about which patients, products and systems justify investment. They do not support a single survival claim for every form of prehospital blood.

PAMPer, COMBAT and RePHILL examined blood-product or plasma resuscitation against different comparators. SWiFT and TOWAR compared whole blood with prehospital components. [4] [5] [7] [8] [9]

The 20 minute finding needs careful interpretation

A post hoc combined analysis of PAMPer and COMBAT included 626 patients. It associated prehospital plasma with improved survival when the prehospital interval exceeded 20 minutes; a survival difference was not demonstrated in the shorter-interval subgroup. Importantly, the interval was measured from arrival on scene to arrival at the trauma center. It included scene care, rather than driving time alone. [6]

This analysis helps explain why a short journey is an incomplete argument. It also supports taking genuinely short treatment intervals seriously. Because it was a post hoc analysis of plasma trials, the 20-minute finding should not become a universal rule for giving or withholding whole blood. It cannot prove benefit for every patient below that interval.

Military evidence also supports examining treatment timing. An observational study of evacuated combat casualties in Afghanistan associated early blood-product transfusion with better survival. Its setting and study design limit direct application to civilian EMS, but it contributes to the rationale for investigating earlier resuscitation. [11]

Whole blood and component therapy remain product choices

Whole blood is attractive because it combines red cells, plasma and platelets in one product. Component therapy allows those elements to be supplied separately. The physiological functions matter, but product configuration should be distinguished from evidence of clinical superiority. [2]

An agency evaluating whole blood should consider its clinical indications, blood-bank partnership, supply, compatibility plan and operational requirements. Agencies using components should evaluate their own readiness with equal care. The 2026 trials give leaders a reason to assess the available options without promising that a whole-blood label guarantees a better outcome. [8] [9]

Red cells, plasma and platelets perform different functions. Whole blood contains them together; this physiological distinction does not establish superior clinical outcomes. [2]

Professional guidance is supportive in some settings and cautious in others

NAEMSP’s 2025 statement supports a high-quality prehospital transfusion program and identifies low-titer group O whole blood as its first-choice product for traumatic life-threatening bleeding. That recommendation predates the 2026 SWiFT and TOWAR results, which should now be part of discussions about product selection. [1] [8] [9]

The 2023 European trauma guideline took a more cautious position: it could not make a clear recommendation for or against prehospital blood products because the evidence was conflicting and implementation required consideration of local circumstances. It also predates the two 2026 trials. These documents should be read with their dates and clinical contexts in view. [3]

I remain in favor of developing this capability where patient need and system readiness support it. Honest advocacy acknowledges uncertainty and commits to measuring the program’s performance.

Blood must support bleeding control and rapid definitive care

Transfusion cannot replace control of the bleeding source. The European guideline recommends prompt local compression for life-threatening open-wound bleeding, appropriate adjunct tourniquet use for life-threatening extremity bleeding, direct transport to an appropriate trauma facility and minimizing time to bleeding control. [3]

A blood program should fit into that care pathway. Its deployment, equipment and crew workflow should support resuscitation while avoiding preventable delays to definitive treatment. That requires training and joint review of what actually happens in the field.

The trauma trials discussed here do not establish the same benefit for every pediatric, obstetric, gastrointestinal or other nontraumatic bleeding presentation. Those populations require their own evidence, medical oversight and selection criteria.

A safe program starts before the cooler reaches the vehicle

The Prehospital Blood Transfusion Coalition’s 2025 civilian EMS guideline describes a program with blood-supplier and hospital coordination, controlled storage and transport, trained clinicians, reaction recognition, documentation and ongoing quality review. These are central to the intervention. [10]

At a minimum, leaders should be able to explain who is eligible, who is authorized and competent to transfuse, how product integrity is maintained, how a suspected reaction is managed, how receiving teams are informed and how every case will be reviewed. Warming and patient-temperature management also belong in the approved clinical plan. [10]

For my own evaluation framework, I would examine time to first transfusion alongside indication adherence, scene and transport intervals, adverse events, temperature records, wastage and patient outcomes. A faster transfusion start is a useful process measure; it should not be treated as proof of improved survival.

A transfusion program connects clinical leadership, blood-bank partnership, training, product handling and case review. This scene is illustrative. [10]

The decision deserves more than a map

Being near a hospital is useful. It should inform the assessment of a blood program, together with actual access to transfusion and definitive care. It should not close the discussion before patient need and local performance have been examined.

Blood products can be lifesaving in hemorrhage care, and randomized evidence demonstrates a prehospital survival benefit in a defined air medical plasma setting. The strongest case for expansion is specific about that evidence, transparent about uncertainty and serious about implementation. [4]

My position is straightforward: when a system can provide appropriate blood resuscitation earlier and safely, that opportunity deserves a rigorous clinical and operational evaluation. Geography alone is not an adequate substitute for that work.

Start the conversation in your system

Does your agency know the actual interval from recognizing life-threatening hemorrhage to starting transfusion? Bring that question to your medical director, receiving trauma center and blood supplier. Review recent cases and identify whether a safe, earlier treatment opportunity exists.

Astera Global Solutions can help EMS and healthcare organizations structure a readiness review, education plan and quality-improvement framework with their clinical partners. Visit Astera Global Solutions or contact info@asteraglobalsolutions.net to discuss your system.

Part 2 will examine who should receive prehospital blood and how to choose between whole blood and component therapy, including the compatibility, special-population and international-practice questions that make product selection more complex than choosing a bag.

References

1. Brown, J. B., Yazer, M. H., Kelly, J., et al. (2025). Prehospital Trauma Compendium: Transfusion of Blood Products in Trauma - A Position Statement and Resource Document of NAEMSP. Prehospital Emergency Care. Read source

2. American Red Cross. (n.d.). Blood components: Plasma, platelets and whole blood. Read source

3. Rossaint, R., Afshari, A., Bouillon, B., et al. (2023). The European guideline on management of major bleeding and coagulopathy following trauma: Sixth edition. Critical Care, 27, 80. Read source

4. Sperry, J. L., Guyette, F. X., Brown, J. B., et al. (2018). Prehospital Plasma during Air Medical Transport in Trauma Patients at Risk for Hemorrhagic Shock. New England Journal of Medicine, 379(4), 315-326. Read source

5. Moore, H. B., Moore, E. E., Chapman, M. P., et al. (2018). Plasma-first resuscitation to treat haemorrhagic shock during emergency ground transportation in an urban area: A randomised trial. The Lancet, 392(10144), 283-291. Read source

6. Pusateri, A. E., Moore, E. E., Moore, H. B., et al. (2020). Association of Prehospital Plasma Transfusion With Survival in Trauma Patients With Hemorrhagic Shock When Transport Times Are Longer Than 20 Minutes: A Post Hoc Analysis of the PAMPer and COMBAT Clinical Trials. JAMA Surgery, 155(2), e195085. Read source

7. Crombie, N., Doughty, H., Bishop, J., et al. (2022). Resuscitation with blood products in patients with trauma-related haemorrhagic shock receiving prehospital care (RePHILL): A multicentre, open-label, randomised, controlled, phase 3 trial. The Lancet Haematology, 9(4), e250-e261. Read source

8. Smith, J. E., Cardigan, R., Sanderson, E., et al. (2026). Prehospital Whole Blood in Traumatic Hemorrhage - A Randomized Controlled Trial. New England Journal of Medicine, 394(23), 2305-2316. Read source

9. Sperry, J. L., Guyette, F. X., Cotton, B. A., et al. (2026). Prehospital Resuscitation with Type O Whole Blood for Trauma and Hemorrhage. New England Journal of Medicine, 394(23), 2317-2328. Read source

10. Levy, M. J., Schaefer, R. M., Obyrne, H., Krohmer, J. R., Bank, E. A., & Holcomb, J. B. (2025). Prehospital blood transfusion coalition clinical practice guideline for civilian emergency medical services. Trauma Surgery & Acute Care Open, 10(3), e001931. Read source

11. Shackelford, S. A., Del Junco, D. J., Powell-Dunford, N., et al. (2017). Association of Prehospital Blood Product Transfusion During Medical Evacuation of Combat Casualties in Afghanistan With Acute and 30-Day Survival. JAMA, 318(16), 1581-1591. Read source