Seven years' experience with early defibrillation by police and paramedics in an emergency medical services system

Abstract

Primary objective: To assess the outcome of patients with out-of-hospital cardiac arrest with ventricular fibrillation as the presenting rhythm in an emergency medical services system utilizing a combined police/paramedic response to provide early defibrillation.

Materials and methods: Police and paramedics were dispatched from law enforcement and ambulance communications centers, respectively. First-arriving personnel delivered initial shocks, all using automated external defibrillators. Patients were classified according to response to initial shocks: restoration of pulses with shocks only or in need of advanced life support, including epinephrine. Discharge survival was defined as return to home without disabling neurologic injury.

Results: Over the 7-year period of study 131 patients presented with ventricular fibrillation: 58 were first treated by police and 73 by paramedics. Restoration of pulses with shocks only and discharge survival were not different in police and paramedic groups, with overall survival of 40% (53 of 131 patients). Among the survivors, 19% (18/95 patients) obtained a spontaneous circulation only after administration of epinephrine and other ALS interventions.

Conclusion: Both restoration of a functional circulation, without need for advanced life support interventions, and discharge survival without neurologic disability are very dependent upon the rapidity with which defibrillation is accomplished, regardless of who delivers the shocks. In addition, a smaller but significant number of patients who require ALS interventions, including epinephrine, for restoration of a spontaneous circulation survive to discharge. Short time differences, on the order of 1 min, are significant determinants of both immediate response to shocks and discharge survival.