Dispatcher-directed bystander initiated cardiopulmonary resuscitation: a safe step, but only a first step, in an integrated approach to improving sudden cardiac arrest survival.

Approximately 330 000 out-of-hospital cardiac arrests (OHCAs) occur annually in the United States; in essence, there are nearly 1000 OHCA events each day.1 However, despite the presence of extensive emergency medical response systems (especially in heavily populated regions) and aggressive steps by both professional organizations and private industry to enhance public awareness of the magnitude of the problem and the need for cardiopulmonary resuscitation (CPR) training,1,2 overall OHCA survival rates generally remain dismal and highly variable from location to location. On average, only 5% of OHCA victims leave the hospital.3–6