Incidence of Prehospital Blood Transfusion for Pediatric Trauma Patients

Injury is the leading cause of death among noninfant pediatric patients in the United States.1 Several studies have established that early blood transfusion in pediatric patients with hemorrhagic shock is associated with reduced mortality and a favorable safety profile.2–4 Pediatric patients who first receive a prehospital blood transfusion have lower 24-hour and in-hospital mortality compared with those who first receive an emergency department blood transfusion, with an estimated number needed to transfuse in the prehospital setting of only 5 to save 1 pediatric life.5 Our objective was to examine the incidence and trend of field-initiated prehospital blood and blood product transfusion by emergency medical services (EMS) for pediatric trauma patients in the United States, stratified by urbanicity.This was a repeated cross-sectional analysis of the National Emergency Medical Services Information System (NEMSIS) Public-Release Research data sets from 2018 to 2023. NEMSIS is the national system used to collect EMS encounter data. We included all 9-1-1 EMS activations for a pediatric patient, defined as age less than 18 years with a traumatic injury who received field-initiated prehospital blood or blood products. Trauma patients were classified based on the Centers for Disease Control and Prevention Injury Mortality Diagnosis Matrix International Classification of Diseases, Tenth Revision, Clinical Modification codes. Patients were included if they received whole blood, packed red blood cells, plasma, and/or platelets. Records were excluded if the activation was only for interfacility transport.Each EMS activation was stratified by urbanicity, as defined by the 2013 US Department of Agriculture Urban Influence Codes. Transport time was determined as the interval between EMS arrival on scene to arrival at the hospital. The frequency of field-initiated prehospital blood transfusion was stratified by urbanicity using descriptive statistics. Field-initiated prehospital blood transfusion trends were assessed using calculated rates with exact Poisson CIs. Observed monthly rates were plotted alongside predicted rates from a negative binomial model with restricted cubic splines because of the nonlinear trend. The predicted values were used to calculate the average annual increase over the study period.There were 351 pediatric trauma patients who received field-initiated prehospital blood during the study period. There were nearly 24 activations with prehospital blood administration per 100 000 EMS pediatric trauma activations (Table 1). Most blood was delivered in urban areas (46%). When stratified per trauma activation, the highest incidence of prehospital transfusion was in wilderness areas (115/100 000 activations), with the lowest in urban areas (13/100 000 activations). Most blood (75%) was administered by air EMS. Overall, pediatric trauma patients who received blood had a median transport time of 21.0 minutes (IQR, 14.3–30.5). From 2018 to 2023, the average annual increase in blood administration was 10.0 (95% CI, 7.1–12.9) per 100 000 pediatric trauma EMS activations (Figure 1).Similar to prior work, our study shows that field-initiated blood transfusion for pediatric trauma patients is rare.5 While the total incidence of blood transfusion occurred most frequently in urban environments, the incidence of transfusion per 100 000 pediatric trauma activations was actually highest in wilderness environments. Patients from wilderness areas have longer transport times and may be most likely to benefit from prehospital transfusion, as prior work evaluating adult prehospital blood transfusion found a mortality benefit when transport times were longer than 20 minutes.6Our study is limited in that NEMSIS is a convenience sample. It is possible that more transfusions occurred during the study period that we cannot account for because of misclassification or underreporting. The number of EMS agencies that contributed data to NEMSIS also increased over time, which may have contributed to a portion of the observed increase if agencies that began reporting to NEMSIS were more likely to perform prehospital transfusion. Finally, we could not determine how frequently EMS units were staffed by critical-care teams.The significant increase in blood administration over time may be due to drivers such as updated blood protocols, increased presence of blood programs, and improved reporting to NEMSIS. However, given that only 1% of hemodynamically unstable adult trauma patients receive prehospital blood, there are likely more pediatric patients who could benefit.7 Further investigation with linked outcomes data is necessary to understand the clinical impact of this changing practice pattern on pediatric survival after injury.