When time counts: Emergency medical dispatch. Exploring, understanding and addressing issues that impact upon timely and adequate allocation of prehospital medical assistance and resources to cardiac arrest patients

When an out-of-hospital cardiac arrest (OHCA) occurs, patient outcome can be influenced by bystanders ability to start cardiopulmonary resuscitation (CPR) before ambulance arrival. Recognition of cardiac arrest and provision of telephone-assisted CPR (T-CPR) by emergency medical dispatchers (EMDs) are key process measures that have been associated with improved survival after OHCA. The aims of this thesis were to provide a comprehensive description and analysis of factors impacting on EMDs when handling cardiac arrest calls. Voice logs of actual cardiac arrest calls in four different emergency medical communication centres (EMCC) were analysed and compared and EMDs were interviewed and observed. A bundle of targeted interventions were performed and evaluated in one EMCC. All included EMCCs faced similar challenges with agonal breathing as the main barrier to recognition of cardiac arrest. Few differences were observed when comparing two commonly used dispatch tools in use in Norway (Criteria Based Dispatch -CBD) and USA (Medical Priority Dispatch-MPD), but T-CPR were offered faster and more frequently in the CBD system. Some variations in performance standards were seen when comparing three different EMCCs in Norway, despite similar organisation, professional backgrounds and dispatch tool/protocols. A mixed-methods approach is effective to explore the challenges regarding OHCA calls in an EMCC, and revealed both use and non-use of protocols, inaccuracy of definition of cardiac arrest and differences in interrogation strategies, in particular concerning assessment of breathing. Monitoring key quality indicators helped identify the challenges to the system, and enabled development of effective strategies to improve quality of care. Targeted simulation, education and feedback significantly increased recognition of OHCA, delivery of T-CPR and reduced time to first chest compression