Impact of temporal changes in the epidemiology and management of traumatic out-of-hospital cardiac arrest on survival outcomes

Aim: We aimed to investigate the impact of temporal changes in the epidemiology and management of traumatic out-of-hospital cardiac arrest (OHCA) on emergency medical service (EMS) attempted resuscitations and survival outcomes. Methods: A retrospective observational study of traumatic OHCA cases involving patients aged > 16 years in Victoria, Australia, who arrested between 2001 and 2018. Unadjusted and adjusted logistic regression was performed to assess trends in survival outcomes over the study period. Results: Between 2001 and 2018, the EMS attended 5,631 cases of traumatic OHCA, of which 1,237 cases (22.0%) received an attempted resuscitation. EMS response times increased significantly over time (from 7.0 min in 2001–03 to 9.8 min in 2016−18; p trend < 0.001) as did rates of bystander cardiopulmonary resuscitation (CPR) (from 37.8% to 63.6%; p trend < 0.001). Helicopter EMS attendance on scene increased from 7.1% to 12.4% (p trend = 0.01), and transports of patients with return of spontaneous circulation (ROSC) to designated major trauma centres also increased from 36.6% to 82.4% (p trend < 0.001). The frequency of EMS trauma-specific interventions increased over the study period, including needle thoracostomy from 7.7% to 61.6% (p trend < 0.001). Although the risk-adjusted odds of ROSC (OR 1.06, 95% CI: 1.03–1.10) and event survival (OR 1.05, 95% CI: 1.01–1.09) increased year-on-year, there were no temporal changes in survival to hospital discharge. Conclusion: Despite higher rates of bystander CPR and EMS trauma interventions, rates of survival following traumatic OHCA did not change over time in our region. More studies are needed to investigate the optimal EMS interventions for improved survival in traumatic OHCA.