The effect of telemetry on urban prehospital cardiac care.

A three-year, controlled trial of the use of telemetry in the prehospital care of cardiac patients was conducted in a major metropolitan area. Five of the ten paramedic squads in the city used telemetry; the other five squads did not. We studied the effect of telemetry on the following: paramedics' abilities to recognize ECGs in a written test; paramedics' abilities to identify ECG arrhythmias in the field; length of time spent by paramedics in the field; survival rates of patients with ventricular fibrillation (VF) cared for by paramedics; abilities of base station physicians to interpret telemetered ECGs; and attitudes of paramedics toward using telemetry. Telemetry was not found to affect the abilities of paramedics to read ECGs in either test or field situations. Paramedics who used telemetry spent more time in the field with their patients than did paramedics who did not use telemetry (P less than .02). We found no statistically significant effect of telemetry on survival rates of VF patients. Using matched ECGs, readings by base station physicians were found to be more accurate than were those by paramedics (P less than .01). Paramedics overwhelmingly reported that telemetry did not help them to save patients' lives, but that it did help them to treat patients with certain arrhythmias. The results suggest that telemetry may not improve either paramedics' abilities to identify arrhythmias or prehospital care for all cardiac patients. The implications for emergency services researchers are discussed.