An emergency medical dispatcher is a professional telecommunicator, tasked with the gathering of information related to medical emergencies, the provision of assistance and instructions by voice, prior to the arrival of emergency medical services (EMS), and the dispatching and support of EMS resources responding to an emergency call. The term "emergency medical dispatcher" is also a certification level and a professional designation, certified through the Association of Public-Safety Communications Officials-International (APCO)Association of Public-Safety Officials-International and the International Academies of Emergency Dispatch. Many dispatchers, whether certified or not, will dispatch using a standard emergency medical dispatch protocol.

History Dispatchers have always played an essential role of emergency medical services (EMS). At its most basic, the role of the dispatcher has been to identify the problem and the location of the patient, and then identify an ambulance that can be sent to the location. Prior to the professionalization of emergency medical services, this step in the process was often informal; the caller would simply call the local ambulance service, the telephone call would be answered (in many cases by the ambulance attendant who would be responding to the call), the location and problem information would be gathered, and an ambulance assigned to complete the task. The ambulance would then complete the call, return to the station, and wait for the next telephone call.

Although earlier experiments with the use of radio communication in ambulances did occur, it was not until the 1950s that the use of radio dispatch became widespread in the United States and Canada. Indeed, during the 1950s the presence of radio dispatch was often treated as marketing inducement, and was prominently displayed on the sides of ambulances, along with other technological advances, such as carrying oxygen. Dispatch methodology was often determined by the business arrangements of the ambulance company. If the ambulance were under contract to the town, it might be dispatched as an 'add-on' to the fire department or police department resources. In some cases, it might be under contract to the local hospital, and dispatched from there. In many cases, small independent ambulance companies were simply dispatched by a family member or employee, employed part-time in many cases. Ambulance dispatchers required little in the way of qualifications, apart from good telephone manners and a knowledge of the local geography.

In a parallel evolution, the development of 9-1-1 as a national emergency number began in Winnipeg, Manitoba, Canada, in 1959. The concept of a single answering point for emergency calls to public safety agencies caught on quickly. In the United States, the decision was made to utilize the Canadian number, for reasons of ease of memory (4-1-1 and 6-1-1 were already in use), and ease of dialing. In 1967, the number was established as the national emergency number for the United States, although by 2008, coverage of the service was still not complete, and about 4 percent of the United States did not have 9-1-1 service. Calling this single number provided the caller access to police, fire and ambulance services, through what would become known as a common public-safety answering point (PSAP). The technology would also continue to evolve, resulting in "Enhanced 9-1-1" including the ability to 'lock' telephone lines on emergency calls, preventing accidental disconnection, and automatic number identification/automatic location identification (ANI/ALI), which permits the dispatcher to verify the number originating the call (screening out potential false alarms), and identifying the location of the call, against the possibility of the caller becoming disconnected or unconscious.

As the skill set of those in the ambulance increased, so did the importance of information. Ambulance service moved from 'first come, first served' or giving priority to whoever sounded the most panicked, to prioritizing based on how severe the medical emergency was. This occurred slowly at first, with local initiatives and full-time ambulance dispatchers making best guesses. Priority codes developed for ambulance dispatch, and became commonplace, although they have never been fully standardized. As it became possible for those in the ambulance to actually save lives, the process of sending the closest appropriate resource to the person in the greatest need became very important. Dispatchers needed tools to help them make the correct decisions, and a number of products were devised for this purpose.

1970s onward One of the first known examples of call triage occurring in the dispatch centre occurred in 1975, when the Phoenix, Arizona Fire Department assigned some of its paramedics to their dispatch centre in order to interview callers and prioritize calls. The following year, Dr. Jeff Clawson, a physician employed by the Salt Lake City Fire Department as its medical director, developed a series of key questions, pre-arrival instructions, and dispatch priorities to be used in the processing of EMS calls. These ultimately evolved into the Medical Priority Dispatch System (MPDS), APCO (EMD) and PowerPhone's Total Response computer aided call handling (CACH) system. Such systems were initially technologically quite primitive; in the mid-1970s the use of computers in dispatching was extremely uncommon, and those that used them were dealing with very large mainframe computers. Most such systems were based on either reference cards or simple flip charts, and have been described by lay people on more than one occasion as being like a "recipe file" for ambulance dispatchers. The development of pre-arrival instructions presented an entirely new challenge for those involved in emergency medical dispatch; it might take eight or more minutes for paramedics to arrive at the patient's side, but dispatchers could be there in seconds. Physicians began to see a dramatic new potential for the saving of lives by means of simple scripted telephone instructions from the dispatcher, and the concept of Dispatch Life Support was born. Suddenly dispatchers were providing complex information and instructions to callers, and even providing guidance on performing procedures such as cardiopulmonary resuscitation (CPR) by telephone. The concept became an area of medical research, and even EMS medical directors debated on the best approach to such services.

As technology, and particularly computer technology, evolved, the dispatching of EMS resources took on an entirely new dimension, and required completely new skill sets. The process of dispatching was supported by computers, and moved in many locales to a paperless system that required above average computer skills. Computer-aided dispatch (CAD) systems not only permitted the dispatcher to record the call information, but also automated the call triage process, allowing EMD systems to become algorithm-based decision support tools. Technologies once available only to the military, such as satellite-based automatic vehicle location allowed CAD systems to constantly monitor the location and status of response resources, making response resource assignment recommendations to human dispatchers, allowing human dispatchers to watch the physical movement of their resources across a computerized map, and creating a permanent record of the call for future use.

Emergency medical dispatchers and prioritized dispatching have become a critical and demanding part of EMS service delivery. The PSAP and, in effect the EMD, become the functional link between the public and allocation of emergency resources, including police, fire and EMS. As the system has evolved and become professionalized, control of the Advanced Medical Priority Dispatch System (MPDS), originally developed by Dr. Jeff Clawson, has been turned over to Medical Priority Consultants, Inc. (now known as Priority Dispatch Corporation),Priority Dispatch Corporation while APCO and PowerPhone developed separate systems. The National Academy of Emergency Medical DispatchersThe Medical Priority Dispatch System: A System and Product Overview was subsequently established by Dr. Clawson as a non-profit advisory organization to develop products and services provided by PDC. A formal process for the development of emergency medical dispatch protocols and guidelines continues to be developed by National Institutes of Health; the National Association of Emergency Medical Services Physicians, a professional association of EMS medical directors; and the National Association of State Emergency Medical Services Directors (NASEMSD).National Association of State Emergency Medical Services Directors

Role In most modern EMS systems, the emergency medical dispatcher (EMD) will fill a number of critical functions.EMD Resources The first of these is the identification of basic call information, including the location and telephone number of the caller, the location of the patient, the general nature of the problem, and any special circumstances. In most EMS systems, the telephone remains almost a singular point of access for those needing assistance.

There are general exceptions to this rule. Most of them still involve 9-1-1 calls, but using new alerting mechanisms upstream from the 9-1-1 call. While these new applications are not directly monitored by the EMD, the EMD nevertheless remains the primary point of contact into the dispatch system. The three most common new applications are: Some public access defibrillators, upon removal, have an alarm built in that triggers an automated 9-1-1 call on the assumption that an AED is being removed for emergency medical reasons. Maintenance removal utilizes an alarm override. Personal safety alarms, designed for use by the elderly or infirm, such as Lifeline. They usually take the form of a bracelet or pendant. The device will have a push-button-activated alarm, and possibly a motion sensor for automatic alarms, which are relayed through a base unit attached to a telephone landline. Most such systems inform a monitoring company, which follow protocol for informing 9-1-1 about the potential emergency of the subscriber. Sophisticated versions of these systems may even allow two-way voice communication among the subscriber, the monitoring company, and emergency dispatch. Vehicle monitoring systems (such as GM OnStar). Such systems have sensors to monitor for vehicle crashes, mobile or satellite telephony to call the monitoring company, and GPS to identify the vehicle's location. In the event that the system detects a possible crash situation, the system will call the monitoring center and submit the crash and location information. If the operator cannot verify with the car's occupants that emergency services are unnecessary, then the operator will call the PSAP appropriate to the vehicle's location. This is becoming increasingly common in North America.