AimWe describe emergency medical services (EMS) protocols and prehospital practice patterns related to traumatic cardiac arrest (TCA) management in the U.S. MethodsWe examined EMS management of TCA by 1) assessing variability in recommended treatments in state EMS protocols for TCA and 2) analyzing EMS care using a nationwide sample of EMS activations. We included EMS activations involving TCA in adult (≥18 years) patients where resuscitation was attempted by EMS. Descriptive statistics for recommended and actual treatments were calculated and compared between blunt and penetrating trauma using χ2 and independent 2-group Mann-Whitney U tests. ResultsThere were 35 state EMS protocols publicly available for review, of which 16 (45.7%) had a specific TCA protocol and 17 (48.5%) had a specific termination of resuscitation protocol for TCA. Recommended treatments varied. We then analyzed 9,565 EMS activations involving TCA (79.1% blunt, 20.9% penetrating). Most activations (93%) were managed by advanced life support. Return of spontaneous circulation was achieved in 25.5% of activations, and resuscitation was terminated by EMS in 26.4% of activations. Median prehospital scene time was 16.4 minutes; scene time was shorter for penetrating mechanisms than blunt (12.0 vs 17.0 min, p < 0.001). Endotracheal intubation was performed in 32.0% of activations, vascular access obtained in 66.6%, crystalloid fluids administered in 28.8%, and adrenaline administered in 60.1%. ConclusionActual and recommended approaches to EMS treatment of TCA vary nationally. These variations in protocols and treatments highlight the need for a standardized approach to prehospital management of TCA in the U.S.