A conversation analytical study of call openings in Emergency Medical Service calls where the patient is at imminent risk of out-of-hospital cardiac arrest

Background: The Chain of Survival identifies the importance of early recognition of patients who are at imminent risk of out-of-hospital cardiac arrest. This research investigated the interaction between callers and call-takers during calls to the Emergency Medical Service; it specifically focussed on patients who were alive at the initiation of the EMS call, but who subsequently deteriorated into out-of-hospital cardiac arrest during the prehospital phase of care (i.e., before arrival at hospital). Methods: Conversation-analytic methods were used to examine the call openings of 38 Emergency Medical Service calls for patients who were at imminent risk of out-of-hospital cardiac arrest. Call openings centred on pre-triage questions designed to rapidly identify patients who are either in out-of-hospital cardiac arrest, or who are at imminent risk of out-of-hospital cardiac arrest. Results: Emergency Medical Service call openings did not facilitate efficient and accurate triage, thus delaying the identification of critically unwell patients by call-takers. In 50% of call openings, the caller wanted to give the reason for the call during the pre-triage questions. The caller and call-takers orientate to different agendas causing delays to call progression and risking information loss that impacts on effective call triage. Conclusions: The design of the Emergency Medical Service call opening can cause interactional trouble, thus impacting on call progression and risking critical information loss. Modifications to the Emergency Medical Service call opening to quickly align the caller and call-taker, communications training for call-takers and public education may support early identification of patients at imminent risk of out-of-hospital cardiac arrest.