Hemorrhage accounts for 30%-40% of injury-related deaths, and it’s the leading cause of potentially preventable death after injury. Many patients die before reaching the trauma bay. Pushing transfusion earlier, in ambulances and helicopters, has been the response.

Researchers in Nebraska used hospitals’ own transfusion records to work out where that blood should go before a program buys a single unit.

From five trauma centers across Omaha and Lincoln, the team flagged every patient whose massive transfusion protocol (MTP) was activated in the trauma bay between June 2019 and March 2025: 338 in Omaha and 89 in Lincoln. They plotted those activations against assault and motor vehicle crash records by ZIP code and tested whether MTP density tracked with known trauma.

It did. The highest-need zones sat in both cities’ downtown cores, and MTP incidence tracked with trauma incidence almost everywhere (in Omaha, χ², 741.22; P < .001). Where the hospital logged the most massive transfusions was where ambulances would most likely need blood on board.

The reason to target is cost. Whole blood is not only expensive but also perishable and easy to waste. Stocking every ambulance strains storage, temperature control, and supply.

What Earlier Blood Access Changes in Practice

Charles Adams, Jr, MD, runs the trauma service at Hackensack University Medical Center in Hackensack, New Jersey, the first Advanced Life Support program in the state licensed to carry blood on its ambulances and aircraft.

Adams said the most significant clinical difference is less coagulopathy and better hemodynamic stability on arrival, with patients arriving with greater capacity to form clots and less hemorrhagic shock.

“Early transfusion with whole blood can prevent the ‘triad of death’ in trauma: hypothermia, acidosis, and coagulopathy,” he said. Patients transfused in the field “often arrive in a more stable condition,” Adams said, letting in-hospital resuscitation be “more focused and less reactive.”

For those who get nothing until arrival, the first task is reversing shock, “which can delay other necessary interventions.”

Daniela Hermelin, MD, transfusion medicine physician at SSM Health Saint Louis University Hospital in St. Louis, Missouri, has built these programs with Emergency Medical Services (EMS) agencies from the blood bank side. “In the past, saline was commonly administered, but over the last 20 years, we have come to better understand that this may actually cause more harm than help, contributing to what is called the lethal triad,” she said. “There are no true substitutes for blood.”

Her crews report something cruder: Patients “pink up,” she said, “regaining color in their face, maintaining more stable vital signs, appearing more alert.” It is anecdotal, she added, and also “a striking and consistently reported observation from prehospital teams.”

The controlled evidence is murkier. Thomas Scalea, MD, physician-in-chief at the R Adams Cowley Shock Trauma Center at the University of Maryland Medical Center in Baltimore, traces the idea to combat medicine.

“The first real breakthrough that demonstrated that more blood saved lives happened really in Iraq,” he said. “A guy named Matt Borgman authored a seminal paper that made everybody change the way we did things.” That was all in the hospital. Pushing it into the field, he said, “makes a lot of sense.”

The civilian trials have split. PAMPer found plasma in air transport cut 30-day mortality by about 10% in patients at risk for hemorrhagic shock; COMBAT, in urban ground EMS, and Britain’s RePHILL (which tested packed red blood cells and lyophilized plasma against saline rather than whole blood against crystalloid) found no benefit.

Scalea blames trial design. “There was a big trial in the UK which showed no difference. But they compared whole blood not to crystalloid but to blood, to red cells and plasma. Well, that’s a different question.” His summary: “We have a certain amount of a fruit salad of data here we’re trying to understand.”

“It’s very clear to me that some people live who wouldn’t have lived before because they have prehospital blood,” Scalea said.

Does field blood change the trauma bay’s prep? Scalea doubts it. “I don’t know that it does,” he said. What it changes is suspicion. “We don’t give prehospital blood to people with a scratch.” A patient bleeding enough to need it en route is badly hurt, “likely going to need an operation to stop their hemorrhage.”

The handoff has to carry a short, specific set of facts. What Adams needs from the crew:

• Type and volume of product given (whole blood or packed red cells)
• The time the transfusion started
• Vital signs and the patient’s response to the transfusion
• Any adverse reactions

Adams said the information allows his trauma team to anticipate needs and avoid duplicating resuscitation efforts already underway.

Scalea expects that to get faster.

“We will soon be in a situation where those vital signs in the field will automatically get transported to the TRU [trauma resuscitation unit],” he said. “We can actually watch what that guy’s blood pressure is. The troopers are busy. They’re trying to keep this guy on earth.”

On who benefits most, all three experts agree it’s those who have lost the most blood volume.

“The sicker you are, the more you are bleeding…the greater the efficacy of prehospital blood,” Scalea said. Adams named blunt trauma with internal hemorrhage, typically from a high-speed crash, and penetrating injury. Distance matters too. Patients with long transport times, rural or remote, “stand to benefit immensely.” Hermelin set a threshold at 30 minutes, especially when a level I trauma center is far off.

It is not for everyone. Adams flagged the patient who declines blood for personal or religious reasons and a clinical limit: If bleeding is easily controlled and the patient is not in shock, “the risks of a transfusion may outweigh the benefits.”

The Systems and Equity Questions

The highest-need ZIP codes were concentrated in neighborhoods that already experience disproportionately high rates of serious injury. The authors frame it as a way to send a scarce product where it’s most likely to be needed.

Scalea kept returning to what running one demands.

“We need to really analyze the data, and we need to be sure we are maintaining the highest safety standards,” he said. “We want to make sure we don’t waste blood. That’s a tragedy. It’s a valuable resource.”

Some of that discipline is now codified.

“The AABB (Association for the Advancement of Blood & Biotherapies) developed prehospital transfusion standards that help guide EMS agencies in building quality management programs, including requirements for storage, transportation, temperature monitoring, product traceability, and overall blood safety practices,” Hermelin said.

The harder problem, in her view, is scale. “As prehospital blood programs continue to expand, there will likely be increasing need for regional planning regarding product allocation, communication pathways, and surge capacity coordination between blood centers, EMS agencies, and hospitals during mass casualty or disaster events.”

The use of prehospital whole blood is expanding past trauma. “There are people with postpartum hemorrhage. They can be given blood. People with a GI [gastrointestinal] bleed,” Scalea said. “It’s for anybody who’s hemorrhaging.”

The number of programs is increasing. Maryland built the first statewide system; Scalea said Howard County now carries blood on its helicopters, with Baltimore to follow. The Nebraska study provides a method for deciding where the next unit rides. “It will be incumbent on us to really analyze those results and be sure that what we’re doing makes sense.”

No disclosures were reported.