Automatic external defibrillation and its effects on neurologic outcome in cardiac arrest patients in an urban,...

To describe the use of the Automatic External Defibrillation (AED) device in an urban, two-tiered Emergency Medical Service (EMS) response setting with regard to its potential effects on cardiac arrest patient survival and neurologic outcome.

A retrospective and descriptive design was utilized to study all cardiac arrest patients that had resuscitations attempted in the prehospital environment over a 30-month period. The study took place in a two-tiered EMS system serving an urban population of 368,383 persons. The first tier of EMS response is provided by the City Fire Department, which is equipped with a standard AED device. All first-tier personnel are trained to the level of Emergency Medical Technician-Basic. The second tier of EMS response is provided by personnel from one of two ambulance services. All second-tier personnel are trained to the level of Emergency Medical Technician-Paramedic.

271 cardiac arrest patients were identified for inclusion. One-hundred nine of these patients (40.2%) had an initial rhythm of either ventricular fibrillation or pulseless ventricular tachycardia and were shocked using the AED upon the arrival of first-tier personnel. Forty-two patients (38.5%) in this group had a return of spontaneous circulation in the field and 22 (20.2%) survived to hospital discharge. Of the survivors, 17 (77.3%) had moderate to good neurologic function at discharge based on the Glasgow-Pittsburgh Cerebral Performance Categories. Faster response times by the first-tier personnel appeared to correlate with better neurologic outcomes.

First responder-based AED usage on patients in ventricular fibrillation or pulseless ventricular tachycardia can be applied successfully in an urban setting utilizing a two-tiered EMS response. In this study, a 20.2% survival to hospital discharge rate was obtained. Seventy-seven percent of these survivors had a moderate to good neurologic outcome based on the Glasgow-Pittsburgh Cerebral Performance Categories.