Title: Improving the ambulance recognition and response for patients who are at imminent risk of cardiac arrest.
Funder: Health Education England

Abstract: Title Improving the ambulance recognition and response for patients who are at imminent risk of cardiac arrest. Background Out-of-hospital cardiac arrest (OHCA) is a catastrophic event requiring immediate intervention. OHCA remains a leading cause of cardiovascular mortality within the United Kingdom (UK) and survival rates are extremely poor. Improving the recognition of patients during a 999 call who are at high risk of suffering an OHCA, and initiating the fastest ambulance response to these patients, has the potential to circumvent the OHCA or improve the patient's chances of survival of OHCA, particularly where the OHCA is witnessed by ambulance staff (also known as emergency medical services; EMS). Communication problems between the call taker and caller caused by confusing medical terms, the emotional state of the caller and the call taker talking too quickly without clarity have previously been reported. OHCA that occurs between the initial call and EMS arrival on scene provide an opportunity to identify interactional patterns that can predict a patient at high risk of imminent cardiac arrest. This knowledge can be used to optimise the ambulance response to this patient group, enhancing their chances of survival. Research Question How can the recognition and response to patients who are at imminent risk of out-of-hospital cardiac arrest be improved? AimsTo improve the early identification of patients contacting the 999 ambulance service who are at imminent risk of cardiac arrest, in order to provide the most timely and effective response possible, thereby reducing mortality and improving clinical outcomes in this high-risk patient group. Objectives Objective 1: To complete a systematic review of primary research investigating the features of a 999 call interaction that facilitate call-taker recognition of patients who are in OHCA, or at imminent risk of OHCA. Objective 2: To understand the current ambulance emergency call triage, ambulance response and survival of patients at imminent risk of OHCA. Two cohorts of OHCA patients will be identified; those that were triaged as requiring the highest priority ambulance response (category 1) and those that were triaged as requiring a lower priority ambulance response (Category 2, 3 or 4).Objective 3: Conversation Analysis of the call-taker and caller interaction on the emergency call to identify call features that may facilitate recognition of patients who are critically unwell and at imminent risk of OHCA. Objective 4: To conduct focus groups with call-takers, dispatchers and clinical supervisors in the Emergency Operations Centre to gather and understand their views on how the findings of this fellowship can be used to improve the recognition and response to patients who are at imminent risk of OHCA. Timelines for Delivery Objective 1 Month 7 Objective 2 Month 11 Objective 3 Month 21 Objective 4 Month 28 Anticipated impact and dissemination This programme of work has the potential to optimise the ambulance service response to patients at imminent risk of OHCA, improving patient survival and long-term outcome following cardiac arrest. The main dissemination strategy will be publication in peer reviewed journals and presentations at relevant conferences.

Lay abstract: Title Improving the ambulance recognition and response for patients who are at imminent risk of cardiac arrest.1.0 Aim To improve the recognition of patients contacting the 999 ambulance service who are at high risk of suffering a cardiac arrest before they reach hospital. 2.0 Background to the research Out-of-hospital cardiac arrest (OHCA) occurs when a patient's heart stops beating suddenly outside hospital. It is a catastrophic event requiring immediate treatment if the patient is to have any chance of survival. OHCA remains a leading cause of death in the United Kingdom (UK). In October 2017 only 1 in 10 OHCA patients treated by the ambulance service survived to leave hospital. The focus of this research is on patients who are alive during a 999 call, but who go on to suffer a cardiac arrest before they reach hospital. The conversation that occurs between the person who calls 999 and the ambulance call handler is particularly important. If we understand more about the patients who are at greatest risk of cardiac arrest and the 999 calls they make we can use this to train ambulance call handlers and control room staff to recognise these patients accurately, so they can send the fastest possible ambulance response and save lives as a result. 3.0 Research Design To start with we will review all the previously published research to understand what is already known about the recognition of patients who suffer an OHCA by ambulance call handlers. All NHS ambulance services routinely collect cardiac arrest data, including whether patients survive. The South Western Ambulance NHS Foundation Trust (SWASFT) cardiac registry data will be looked at over a two year period and linked to information collected during the 999 call, to understand the response that patients at high risk of cardiac arrest receive from the ambulance service currently. These 999 calls will be divided into those calls that correctly received the highest priority response and those that did not. From each of these groups twenty-five 999 call recordings will be analysed using a technique called conversation analysis (CA). We have chosen fifty calls because by random selection and by selecting cases of particular interest new knowledge will be generated for analysis. CA is a well-established method of looking at the way that people talk to each other, and will help us to understand what words and techniques can help to identify a person who is at high risk of cardiac arrest. We will discuss all our research findings with 999 call handlers and ambulance control room staff to decide how we can use this research to help staff recognise people at high risk of cardiac arrest. 4.0 Patient and Public Involvement A member of SWASFT's Patient and Public Involvement (PPI) in Research Group, who is also a cardiac arrest survivor, has agreed to act as an advisor throughout this research. Also, a well-established group of OHCA survivors and their close friends and relatives have reviewed this project on two occasions and helped to develop and improve the research plan. This group supports the project and have agreed to help complete the work and publicise the findings. 5.0 Dissemination The results of this research will be published in medical journals and presented at conferences. The results will also be given to all the ambulance services in the United Kingdom, and to patients and the public through a website, press articles and using social media. This research will help to inform the way that 999 calls are handled in the future, and to support ambulance staff in making better decisions.

Research activity codes: 8.1 ORGANISATION AND DELIVERY OF SERVICES;8.3 POLICY, ETHICS AND RESEARCH GOVERNANCE
Health categories: CARDIOVASCULAR