The deployment of Enhanced Care Teams (ECTs) capable of delivering advanced clinical interventions for patients at the scene of incidents is commonplace by Emergency Medical Services in most developed countries. It is unclear whether primary dispatch models for ECT resources are more efficient at targeting deployment to patients with severe trauma than secondary dispatch, following requests from EMS personnel at scene. The objective of this study was to review the evidence for primary and secondary models in the targeted dispatch of ECT resources to patients with severe traumatic injury.