Science of Emergency Medical Dispatch

Out-of-hospital cardiac arrest (OOH-CA) claims the lives of almost 300 000 Americans each year,1 a loss of life equivalent to that caused by a September 11 World Trade Center attack on the United States every 3 days! Despite advances in public education on recognition of cardiac arrest, early notification of emergency medical services (EMS) 9-1-1 centers, lay bystander cardiopulmonary resuscitation, automated external defibrillator use, and improvements in EMS service delivery, fewer than 8% of adult OOH-CA victims survive to hospital discharge.1Article p 2096 Most neurologically intact survivors come from the 20% to 38% of OOH-CA patients who have ventricular fibrillation as their first recorded rhythm, and the percentage of cases with a first recorded rhythm of ventricular fibrillation is decreasing nationally despite a near-constant incidence of OOH-CA.1 A sudden cardiac arrest victim’s chances of survival decrease 7% to 10% for every minute of delay until defibrillation.2 The “chain of survival” paradigm of the American Heart Association lists the community “links” necessary (early access, early cardiopulmonary resuscitation, early defibrillation, early advanced life support) to optimize survival from OOH-CA. The first link, early access, includes public education on recognition of cardiac arrest and notification of the EMS system (“call 9-1-1”) by anyone witnessing the event, as well as rapid dispatch of trained and properly equipped emergency rescuers to the scene.An emergency medical dispatcher must have the training, protocols, experience, and poise to interrogate callers quickly and accurately to determine whether a life-threatening emergency has occurred and, if so, to send the appropriate public safety resources to the scene promptly. In the United States, most 9-1-1 center “public safety answering point” (PSAP) call takers are not medically trained personnel but individuals who must handle police, fire, and medical emergency calls. In a minority of high-performance EMS systems, …