Patients With Traumatic Cardiac Arrest Assessed by the Danish HEMS

Inclusion Criteria: * This study includes all patients (adults and children) with TCA in Denmark between 2016 and 2021 who were treated by the Danish HEMS. Patients will be included if they suffered from an OHCA from traumatic origin and were assessed by the Danish HEMS. The latter will be identified through manual validation based on a predefined search string among all OHCAs in Denmark (derived from the Danish Cardiac Arrest Registry) within the study period. Exclusion Criteria: * Patients in whom the HEMS was dispatched but did not arrive will be excluded. * Patients with cardiac arrest resulting from hanging, drowning, or electrocution will be excluded. * Further, patients without a valid personal identification number and non-Danish citizens will be excluded.