Nationwide Study Assesses Prehospital Transfusion

Nationwide, the use of whole blood (WB) in prehospital transfusion (PHT) tripled between 2020 and 2024, based on the results of a study aimed at assessing transfusion practices of emergency medical services (EMS). Investigators published their findings July 31 in JAMA Network Open.

Overall, whole blood use increased from 10% of transfused units in 2020 to 30.8% in 2024, according to a cohort study of 10,444 patients who received PHT. Investigators observed regional variations in WB use, with the highest use seen in the Northeast (33.2%) compared with the Midwest (16.5%).

The findings come from the Characteristics, Regional Evaluation and D-Antigen in Transfusions by EMS (CREDIT-EMS) study, one of the first large-scale attempts to quantify and understand nationwide civilian PHT practices in the United States. The observational retrospective cohort study analyzed prehospital data to present national and regional five-year PHT trends. The study is based on six data sources, representing more than 500 EMS services that provide PHT nationwide.

WB or red blood cells were used in 88% of PHT cases, while plasma-only transfusions occurred in 12.1% of patients. Plasma-only transfusions were most common in the South (13.3%, 7,781 patients), compared with all other regions combined.

For the study, PHT was defined as the administration of WB or any component in the prehospital air or ground response setting. In addition, civilian PHT included only transfusions initiated by participating EMS agencies. Patients of any age with any diagnosis were eligible if their cases were scene transports between January 2020 and October 2024.

The average patient age in the total cohort of 10,444 individuals was 45 years; 70% of the 10,439 patients who received one or more units of blood products during PHT were male. Most patients (80.6%) had a trauma diagnosis, and nearly all (97.4%) were transported by air.

The 10,444 patients had a total of 17,927 transfused units of various types of blood products: 88% received WB and/or RBCs, and 47.9% received two or more units of blood products. Among all patients, 80.1% received at least one fully transfused unit before hospital arrival, with 37.4% receiving at least two full units.

In terms of transport time, even in the South, which had the shortest median transport time, the median prehospital time was 46 minutes.

D-Positive Exposure Risks for Females of Childbearing Potential

The researchers also assessed D-positive blood administration in D-negative women of childbearing potential (FCP)(aged 12 to 50 years). There were 10,438 patients with known FCP status, and 15.9% (1,589 of 10,438) were aged 12-50 years. In total, 60% of FCP received at least one unit of D-positive WB or RBCs; 13.7% overall received two or more D-positive WB or RBC units.

The researchers found that D-positive exposure was more common for FCPs who received WB compared with those receiving only RBCs. Nearly all FCPs (87.7%) received WB or RBCs. Among these patients, 68.7% of whom who received at least one unit of D-positive WB or RBCs, the relative proportion of receipt of D-positive blood products was significantly greater for those who received WB compared with the reference group of those who did not receive WB (relative risk, 1.53; P < .001).

Notably, there were significant regional differences in the likelihood of FCPs receiving D-positive WB or RBC. Those in the West were more likely than those in the South or Midwest to receive at least one unit. Those in the West were also more likely than those in the South or Midwest to receive multiple units.

“Our data demonstrate that as PHT shifts toward WB there is an accompanying increase in D-positive exposure to females of childbearing potential. The rate at which these females of childbearing potential are receiving D-positive WB or RBCs is on the rise, from 73 of 169 (43.20%) in 2020 to 372 of 497 in 2024,” the authors said.