Detection of obvious death by clinically trained emergency medical dispatchers in a criteria-based dispatch system.

Background: More than a third of out-of-hospital cardiac arrests in the European Union do not benefit from cardiopulmonary resuscitation by emergency medical services (EMS), most often because the patient shows signs of obvious death. To preserve limited resources, it is crucial for dispatch centres to identify such cases and thereby reduce over-triage. The aim of this study was to assess the ability of clinically trained dispatchers to detect obvious deaths among all suspected out-of-hospital cardiac arrests within a criteria-based dispatch system.

Methods: This retrospective single-centre study was conducted from June 2020 to January 2022. All calls in which dispatchers suspected an out-of-hospital cardiac arrest were included. Dispatchers’ decisions (priority versus non-priority dispatch) were used to determine whether obvious death was suspected. These were then compared to EMS’ decisions (resuscitation versus no resuscitation) to assess the appropriateness of the dispatch response.

Results: In total, 1,042 calls were included. Among the 335 patients confirmed as obviously dead by EMS, 80 received a non-priority dispatch (sensitivity: 23.9%). Among the 707 patients who were either resuscitated or not in cardiac arrest, 694 received a priority dispatch (specificity: 98.2%). Sensitivity increased to 33.1% when dispatchers actively searched for signs of obvious death. Of the 93 cases judged by dispatchers to be obvious deaths, 80 were confirmed (positive predictive value: 86.0%). Among the 949 patients in whom dispatchers did not suspect obvious death, 694 were resuscitated or not in cardiac arrest (negative predictive value: 73.1%).

Conclusions: The sensitivity of dispatchers in detecting obvious death was 23.9%, increasing to 33.1% when signs of obvious death were actively sought. In the context of limited EMS resources, it is vital to develop and implement protocols that reduce over-triage. For unwitnessed out-of-hospital cardiac arrests, a systematic search for clinical signs of obvious death appears essential.

Supplementary Information: The online version contains supplementary material available at 10.1186/s12245-025-00919-y.