Objectives of this study were to determine the number of prehospital emergency patients who were given advanced life support (ALS) drugs and to compare utilization rates for ALS drugs in urban and rural environments. Certified ALS emergency medical technicians (Arizona) have 29 therapeutic agents authorized for prehospital administration. These agents may be administered only under direction of a medical control authority or by following standing orders.

A retrospective review was made of prehospital emergency encounter records. They were acquired by the Arizona Office of Emergency Medical Services (OEMS) from rural EMS providers who used optically scannable forms and from a metropolitan fire department's medical emergency response records.

In 1989 and 1990, 273,611 emergency patient encounter records were entered into the EMS database; 197,260 were urban responses and 76,351 were rural responses. Drugs (ALS) were administered to 16,730 (8.5%) urban emergency patients and to 5,359 (7%) rural emergency patients at the incident site or during transport to a medical care facility. Nitrostat, 0.4 mg sublingual tablet, was the drug most frequently administered to emergency patients in the prehospital setting. Utilization rates found in the urban and the rural data sets were consistent for the indivdual agents. Variations in use frequency between urban and rural setting were noted for some drugs. Of the 29 approved ALS drugs, seven (24%) were administered to 10% or more urban patients who received drugs. In the rural areas, eight (27.6%) were administered to 10% or more patients who received drugs. There were nine (31%) agents administered to less than 1% of all patients who received drugs. A majority of the approved drugs, 17 (59%) were administered at a rate below 5% of all patients receiving medications.

Severity of illness or injury prompted administration of ALS drugs to 8.1% of patients receiving prehospital emergency care. The most frequently utilized medication in the urban/rural areas was for treatment of cardiac symptoms. Variations between urban/rural drug utilization reflected the drugs of choice which are compatible with long transport times to a medical facility.