Survival outcomes in emergency medical services witnessed traumatic out-of-hospital cardiac arrest after the introduction of a trauma-based resuscitation protocol

Aim: In this study, we examine the impact of a trauma-based resuscitation protocol on survival outcomes following emergency medical services (EMS) witnessed traumatic out-of-hospital cardiac arrest (OHCA). Methods: We included EMS-witnessed OHCAs arising from trauma and occurring between 2008 and 2019. In December 2016, a new resuscitation protocol for traumatic OHCA was introduced prioritising the treatment of potentially reversible causes before conventional cardiopulmonary resuscitation. The effect of the new protocol on survival outcomes was assessed using adjusted multivariable logistic regression models. Results: Paramedics attempted resuscitation on 490 patients, with 341 (69.6%) and 149 (30.4%) occurring during the control and intervention periods, respectively. A reduction in the proportion of cases receiving cardiopulmonary resuscitation and epinephrine administration were found in the intervention period compared to the control period, whereas trauma-based interventions increased significantly, including blood administration (pre-arrest: 17.9% vs 3.7%; intra-arrest: 24.1% vs 2.7%), splinting (pre-arrest: 38.6% vs 17.1%; intra-arrest: 20.7% vs 5.2%), and finger thoracostomy (pre-arrest: 13.1% vs 0.6%; intra-arrest: 22.8% vs 0.9%), respectively, with p-values < 0.001 for all comparisons. After adjustment, the trauma-based resuscitation protocol was not associated with an improvement in survival to hospital discharge (AOR 1.29, 95% CI: 0.51–3.23), event survival (AOR 0.72, 95% CI: 0.41–1.28) or prehospital return of spontaneous circulation (AOR 0.63, 95% CI: 0.39–1.03). Conclusion: In our region, the introduction of a trauma-based resuscitation protocol led to an increase in the delivery of almost all trauma interventions; however, this did not translate into better survival outcomes following EMS-witnessed traumatic OHCA.