Does the initial description of an out-of-hospital cardiac arrest given by callers contacting Emergency Medical Services contain key indicator words which can be used to support appropriate resource deployment?
Resuscitation · 2026-03-17 · Registry study
Abstract
AIMS: Dispatching resources to patients following an out-of-hospital cardiac arrest (OHCA) is an important task for Emergency Medical Services (EMS). Whilst allocation of multiple resources to an OHCA may optimise a resuscitation attempt, this could delay responses for other patients within the community. This study aimed to analyse the initial description given by EMS callers to identify terms associated with a patient's clinical outcome. METHODS: We completed a retrospective review of 37,532 OHCA electronic health records between 01/04/2020 and 31/03/2023 from a single English EMS. Unique identifiers linked call data with clinical records and outcome at 30 days. Patients who had resuscitation withheld and those who survived to 30 days were of particular interest. EMS callers' initial descriptions were analysed with single, double and triple word phrases studied. RESULTS: Thirteen 'Lifeless' descriptors were identified which had stronger association with resuscitation being withheld; 56.6% of calls with these descriptors still received the highest level of EMS response. Four terms were identified that had a better association with survival to 30 days, these terms often described symptoms e.g. "chest pain" or" sweating". Chi-square analysis demonstrated significance (p < 0.001) for both subgroups. CONCLUSION: Analysis of information volunteered by an EMS caller may be able to predict clinical outcome, particularly for patients who have resuscitation withheld on EMS arrival. Current protocols may not consider this information and could result in high acuity responses for patients who are unlikely to survive. This study of unstructured call narratives should supplement existing practice to assist with resource deployment.