Photo by Elise Amendola
In-flight red blood cell (RBC) transfusions can improve outcomes in trauma patients, according to a study published in the Journal of the American College of Surgeons.
The research showed that air-lifted trauma victims who received blood transfusions in the helicopter had higher one-day survival rates and a lower risk of shock than air-lifted patients who did not receive transfusions until they arrived at the trauma unit.
Patients who received in-flight transfusions also required fewer RBCs once they arrived at the hospital.
Joshua Brown, MD, and his colleagues at the University of Pittsburgh Medical Center (UPMC) conducted this research, evaluating the air medical evacuation strategy at UPMC, which has a network of 18 helicopter bases in Pennsylvania, Ohio, and Maryland.
The STAT MedEvac helicopter teams have been carrying blood for transfusion on their flights for about 2 decades, but this is the first study that evaluated the use of transfused blood in civilian trauma victims air-evacuated directly from the injury scene and compared them with air-evacuated trauma victims who did not receive transfused blood.
It is also the largest study to date of a civilian in-flight trauma resuscitation protocol that has been used by the military in Iraq and Afghanistan.
The researchers evaluated 240 patients who received in-flight RBC transfusions and 480 patients who were not transfused until they reached the trauma center.
Receiving an in-flight transfusion was associated with better odds of 24-hour survival (adjusted odds ratio=4.92, P=0.01), decreased odds of shock (adjusted odds ratio=0.28, P=0.03), and lower 24-hour RBC requirement (coef -3.6 RBC units, P=0.04).
Based on these data, the UPMC may modify its protocol, Dr Brown said.
“It used to be the paramedics had to give the patient 2 liters of saline before giving them blood, and we dropped that down to only 1 liter of saline,” he noted. “Now, based on this study, we’re actually looking at giving patients blood without any saline who meet the criteria of low blood pressure and elevated heart rate and are clearly in shock.”
The UPMC protocol involves giving guidelines on when to administer transfusions to the paramedics and nurses onboard flights. All the STAT MedEvac flights at the institution carry 2 units of RBCs for transfusion.
Helicopter staff can communicate with the medical command doctor at the trauma center to get the go-ahead order to give blood to patients who may not meet the guidelines for transfusion but still may benefit from receiving it.
However, there are regulatory issues that may prevent such a protocol from being adopted universally, Dr Brown noted. In Pennsylvania, paramedics who have had additional training are allowed to start a blood transfusion without a physician present, but not all states allow this.
Dr Brown also explained the logistics and challenges of storing blood away from the blood bank.
“The blood needs to be refrigerated, the helicopter base must have a freezer, and the helicopters must have coolers when they’re actually out on a mission to keep the blood at an appropriate temperature,” he said.
Meeting these requirements involves close coordination with the blood bank and having a way to return unused blood after it expires in 30 days. The University of Pittsburgh has registered all of its helicopter bases as satellite blood banks to comply with the regulations.
