As emergency medical systems have developed in recent years, they have functioned under a number of presumptions. Chief among these is the conviction that the time, work, and money involved in the development of such systems reap tangible benefits for society in terms of lives saved and prolonged.
It has also been presumed by those active in the field that the effectiveness of emergency medical services (EMSs) is directly related to the speed with which such services can be provided in times of crisis. Such a presumption is only the logical extension of battlefield experience, which proved that rapid stabilization of the conditions of severely wounded patients before evacuation for definitive care resulted in notable decreases in morbidity and mortality.
When physicians used to such sophisticated battlefield intervention began returning from Vietnam to practice in their native country, they found relatively primitive emergency-response systems. Ambulance attendants required less formal training