Emergency medical services priority dispatch.

STUDY OBJECTIVE: To test the ability of a locally designed priority dispatch system to safely exclude the need for advanced life support (ALS).

DESIGN: Retrospective review of emergency medical services (EMS) incident records to determine how often the lone dispatch of basic life support (BLS) units, staffed with basic emergency medical technicians, subsequently required or involved ALS care.

SETTING: A large centralized municipal EMS system with a tiered ALS/BLS ambulance response. All BLS units carry automated defibrillators.

MEASUREMENTS: Consecutive EMS records (35,075) were reviewed by computerized search for ALS procedures. Records indicating ALS procedures were tabulated and then manually reviewed for the nature of and probable indication for the ALS intervention.

INTERVENTION: Brief sequences of computer-stored questions that help dispatchers identify (or exclude) signs and symptoms indicating the need for ALS.

RESULTS: The dispatch triage system spared ALS units from initial dispatch in 14,100 of the EMS incidents (40.2%), increasing their availability and use for more serious calls. Among these 14,100 cases, only 41 patients (0.3%) later received drugs such as nitroglycerin and naloxone; another 27 patients (0.2%) received resuscitative interventions such as epinephrine or defibrillation. Furthermore, on closer analysis, the immediate presence of a paramedic might have provided a true potential for advantage in outcome for only five or six patients (less than 0.04 of the 14,100 BLS dispatches). Meanwhile, many important operational, fiscal, and cost-effective patient care benefits were realized with this system.

CONCLUSION: A computer-aided dispatch triage algorithm can facilitate improvements in both EMS system operations and prehospital patient care by safely and reliably identifying EMS incidents requiring only BLS.