The way forward for prehospital transfusion

The Stat Medevac helicopter service has two units on board at all times, and each helicopter base has its own approved onsite blood storage, he says. “When a dispatch is made, our operating procedures set the quantity of units it needs. But there are times when we’ve needed more and don’t have it. The program has to ask how much it can carry. How much weight can we fly with? How much should we have to make sure we’re not wasting units?”

Avoiding waste would be a concern for ground-based 911 operations, Dr. Weiss says. “We pick it up directly from the blood services at our trauma centers, they’re transferred to a cooler that we’ve had validated for up to 12 hours of carrying on ice, and then we return the product if it’s not used so it can go right back into the pool.”

“I also have a low threshold to treat a patient with the blood and don’t even think of that as waste,” he continues. “If a patient has any sign of instability after a trauma event, blood is a given. Our training is to use blood appropriately, but if there’s even an inkling of instability after a trauma event, we give blood without a second thought.”

The usual expectation to avoid waste has to be reconsidered for an intervention where the blood product provides a lot of benefit but is used in an unpredictable, episodic manner, Dr. Yazer says. “In Pittsburgh, we waste about 19 percent of the whole blood units we collect—about two units per day—because we were unable to transfuse it to an injured patient or we couldn’t manufacture a red cell from it and use that red cell.”

“If we wasted that many platelets per day, the transfusion service would have to really reflect on why that was happening,” he continues. “But a higher percentage of wastage in this setting translates to a fairly small number of units overall. The way the evidence is pointing, it’s better to over-provide blood to the resuscitation than to leave the patient without. We don’t want to be without blood products in the prehospital setting, so we tolerate a higher degree of wastage there, although we are also looking at ways to reduce the wastage.”

Decisions about resuscitation using prehospital transfusion expose the institution to minimal liability, he says, “as long as we’re following the standard of care according to the scope of practice, and as long as we have a trained individual give the blood in an appropriate fashion.”

The different standard of care is central to the liability question, however. “Right now, if I was in a hospital and someone needed blood and I didn’t give them blood, I would be liable because I’m able to do it and I should do it.” In the field, Dr. Yazer says, the EMS program is working on developing the same expectation, at least in the traditional 911 ground ambulance programs. “And eventually I hope prehospital administration of blood products will be the standard of care, and then that pendulum will swing.”

Transfusion reactions, in Dr. Weiss’ experience with prehospital transfusion, have been rare and mild when they do occur. “In the immediate trauma patient, we will give untyped, or type O, uncrossmatched blood, and I’ve very rarely seen a major reaction. You can have a mild fever or allergic reaction in a small percent of the population. And some of the more serious hemolytic reactions are exceedingly rare.”

Even in the instance of a severe response like anaphylactic or hemolytic reactions, “it’s difficult to tell if the hypotension is caused because the patient has just started to bleed even worse, or because of the blood product unit.”

“If a patient in a prehospital setting is injured and needs a transfusion, they may die without intervention, so the balance shifts toward just going with the transfusion,” Dr. Weiss says.

Some might question the release of O-negative blood for potential use in the field when there is a likely real need in the hospital, particularly when blood products are in short supply. Says Dr. Yazer: “I think that producing whole blood for the prehospital setting ought to be a priority. The faster we get blood products to patients, the faster the bleeding is going to stop, so we may not need as many blood products [later] in the hospital.”

Staff shortages too raise questions and barriers. The staff shortage that has become widespread in post-pandemic health care has had an impact at UPMC, but newer prehospital transfusion programs are more likely to be hurt by the shortage than those that are more established, Dr. Yazer says. “It might affect them if the blood centers did not have enough personnel to determine if a unit is a low-titer unit, so they opt to just make a red cell and plasma from it because that’s easier to do. So there might be fewer products available at the beginning” of a prehospital transfusion program.

“If a center has not yet implemented whole blood, they might not have the staffing to go about learning the regulations and buying refrigerators and monitoring. The center would have to prioritize what they want to do with the staff they have.”

Staffing shortages have affected the nurses and field paramedics more than the physicians at UPMC and the surrounding municipality, Dr. Weiss says. “We worry we’re not going to have enough responders to go on calls or they’re going to be on multiple shifts and could be fatigued.” Some EMS agencies have closed ambulance and helicopter bases nationwide owing to staff shortages, he says. Resource limitations and limited bandwidth mean specialized programs like prehospital transfusion will suffer because they involve more than maintaining the basic level of care. “And it’s a very scary situation in health care right now.”

The THOR-AABB recommendations are not to be considered standards for prehospital transfusion. They’re a road map for centers to think about when establishing a prehospital transfusion program. “They are not to be considered standards under which centers could be audited and inspected,” Dr. Yazer says, and in fact the AABB chose the label “recommendations” to steer clear of an implication that formal regulation of prehospital transfusion should be required.

“What needs to be regulated, the number one thing, is how to take care of the blood products and to make sure that, wherever they are, they are in compliance with proper storage conditions. And the EMS would already have to be in compliance with those standards before they started transporting and administering blood products.”

Here is a sampling of the recommendations for prehospital transfusion programs:

• Medical oversight by an EMS physician medical director is a mandatory component. This medical director approves the training program, credentials the providers, and oversees the associated ongoing quality program.
• The transfusion should be initiated only by personnel trained to administer transfusions. Aspects of such training would include, in part, logistics of product management, types of blood products, administration guidelines, acute adverse event management guidelines, appropriate hand-off procedures, and documentation.
• Documentation of the prehospital transfusion should consist, at minimum, of product type (RBC, plasma, low titer O whole blood), ABO and Rh group as applicable, blood product unit numbers, volume transfused, and noted or suspected adverse events. The form containing this information should be forwarded to the blood bank at the receiving hospital.
• A segment from the RBC/LTOWB unit(s) that was or were transfused in the prehospital phase should be sent to the hospital blood bank for crossmatching.
• If an RhD-positive RBC or LTOWB unit has been administered to a female patient who appears to be of childbearing age, this information in particular should be communicated to the receiving team and the hospital blood bank.
• There must be a plan for the disposition of unused blood products. The ability to prove that the cold chain has been maintained while the products were outside a monitored refrigerator or long-term storage cooler is essential for the integrity of the returns process.

A list of the indications for transfusion can be developed locally, as can the transfusion threshold and rate of infusion, Dr. Yazer says, and having the flexibility to determine some things locally will help with uptake of this process. “I don’t think we should be imposing non-evidence-based things on programs. Let them evolve, let them read the literature, let them set their own practices based on their local needs,” he says.

Asked whether an EMS agency might want to consider partnering with a regional blood center for its products instead of a hospital, Dr. Yazer says it should do whatever makes it easiest to obtain blood. “But partnering with a hospital system that has experience in the remote storage of blood products can save the EMS time and effort by copying what has already been done and what works at a hospital,” he says. “Plus, a large trauma center likely has a dedicated transfusion physician who can be a great asset in developing the program.”

Any hospital administration that is considering launch of a prehospital transfusion program should engage with a team of academic and non-academic medical specialists working closely with trauma and emergency medicine and the pathology and laboratory medicine department, in addition to the EMS agencies, to build its program, Dr. Weiss advises. (He says there are no published data on the number of programs in existence today but estimates organized 911 blood programs at fewer than 10.) He hopes hospitals with a prehospital transfusion program will advocate for scope-of-practice models that will allow a wider use of the blood in the field by paramedics.

“Working with the paramedics and nurses in the field is a unique experience, and helping patients at the point of injury is rewarding,” he says. He appreciates the access they now have, having gone from a hospital-laboratory–based treatment to a treatment that is deployable in the field. “It makes a difference,” Dr. Weiss says. “The quality measures that are enforced, the training, and the willingness to release blood products in unique ways save lives, and that should be commended on all sides.”

Anne Paxton is a writer and attorney in Seattle.