Emergency Medical Services
Background: Traumatic injury is the leading cause of pediatric mortality and emergency medical services (EMS) transport in the United States. A mortality benefit with helicopter EMS (HEMS) transport compared to ground EMS (GEMS) has not yet been shown in this population despite frequent HEMS use.
Methods: We retrospectively analyzed data from the North Carolina Trauma Registry for patients under 16 years of age who presented to a Level I trauma center directly from the scene after experiencing blunt or penetrating trauma between 2013 and 2017. Propensity scoring was used to compare the effect of transport mode, injury severity, age, distance traveled, and sex on in-hospital mortality. Severity was measured by discretized Injury Severity Scores (ISS), with 1-8 as mild, 9-14 as moderate, 16-24 as major, and >24 as severe. Age and straight-line distance in miles were incorporated as continuous variables.
Results: Propensity scoring yielded 384 pairs matched 1:1 by transport mode. There were 23 fatalities (6.0%) in the GEMS group and 19 (4.9%) in HEMS. Overall mortality was 5.4%.C-statistic was 0.90. Males made up 68.7% in both groups. Injury Severity Scores were similar between groups with a total of 50.5% minor, 28.6% moderate, 11.0% major, and 9.9% severe. Mean age was 9.3 for GEMS and 9.4 for HEMS. Mean distance traveled was 21.7 (CI 20.5-22.9) miles for GEMS and 44.2 (CI 42.4-46.0) for HEMS. The effect of HEMS transport on survival was not statistically significant (OR 1.66, CI 0.7-4.2). Higher ISS was found to be the greatest predictor of mortality (minor vs severe OR 144.7, CI 31.9-656.6; moderate vs severe OR 27.1, CI 9.5-76.9; major vs severe OR 5.9, CI 2.4-14.8). Greater age had a similar protective effect (OR 1.1, CI 1.0-1.2) while gender and linear distance were not statistically significant (OR 1.2, CI 0.5-2.8 and OR 1.0, CI 1.0-1.0, respectively)
Conclusion: Greater age and lower Injury Severity Score are both associated with improved survival. Distance of transport, gender, and mode of transport do not have statistically significant effects. Further analysis is needed to determine which patients, if any, benefit from HEMS utilization.