Prehospital Critical Care Response Units (CCRUs) dispatched to the scene of major traumas can deliver advanced interventions at scene but are uncommon in North America. We sought to evaluate the feasibility of CCRU response to major trauma in a North American urban-suburban region.

We obtained ambulance record-level data from three paramedic services in Ontario, Canada (Toronto Paramedic Service, Peel Regional Paramedic Service, and Halton Region Paramedic Service) from January 2018 to December 2022 which we aggregated into calls and applied inclusion criteria targeting major trauma. We used mathematical modelling to determine the optimal placement of CCRU bases containing an RRV or RRV/helicopter for trauma response and evaluated their expected counterfactual coverage performance using simulation. Our primary metrics were the expected number of major traumas that could have been reached by CCRUs prior to EMS departure from the scene and the resulting expected average reduction in time to accessing critical care for those patients.

We found the expected counterfactual coverage of two optimally placed RRV teams to be 80 % (N = 5092) of 6391 major trauma calls included. This corresponded to an expected average reduction in time to critical care of 30 min (from 47 to 17 min). We found only marginal improvement in total calls reached by CCRUs when an RRV team was replaced with an RRV/helicopter team.

Our analysis supports the feasibility of CCRU response to major trauma in a North American mixed urban-suburban region and motivates further investigation into CCRUs' clinical and cost effectiveness.