Search Terms: The Medical Priority Dispatch System (MPDS); emergency responders; Emergency Medical Dispatcher (EMD); EMD protocols; entry-level protocol; chief-complaint protocol; pre-arrival instruction protocol; medically approved interrogation sequence; locally determined preplanned responses; medically appropriate instructions to the caller; response determinant code; medical "statistical probability"; rational response; use of lights and siren; vehicle-related collisions; dispatcher training; four core components of medical dispatch; introduction of the non-lights-and-siren response concept; prearrival care; Pre-Arrival Instructions; Post-Dispatch Instructions; fire-based EMD; the goal of the MPDS; advantages of a properly initiated MPDS; implementation strategy; medical dispatch quality-assurance and improvement program; alternatives to traditional 911 services; protocol vs. guidelines; reimbursement of ambulance transport charges.

EMD: Making the most of EMS
By Jeff J. Clawson, M.D., Board of Certification Chair; Robert L. Martin, Executive Director; Geoffrey A. Cady, Call Processing Board Acting Chair; and Robert Sinclair, Senior Research and Technical Specialist; National Academy of Emergency Medical Dispatch Salt Lake City

As emergency medical dispatch becomes increasingly complex, dispatchers will need relevant and consistent training to perform their duties. The Medical Priority Dispatch System can help agencies train their dispatchers, meet the growing demands for emergency services and ultimately lower costs.

Almost 90% of America's fire departments have a role in providing prehospital medical care and transportation. These fire service-based EMS systems are repeatedly faced with the uncomfortable dilemma of providing prompt and appropriate EMS response in the face of rising costs and increasing service demands. A large number of callers requesting emergency service for non-emergency situations adds to the dilemma. These trends will continue, so it's essential that fire service-based EMS providers understand and effectively use modern emergency medical dispatch tools.

In the last 25 years, the expertise of emergency responders has significantly improved. With EMTs now receiving hundreds of hours of training and paramedics often more than 1,000 hours, it's obvious that education is considered vitally important in the EMS world. However, it's a sad commentary that at the center of many modern, well-trained, specialized and expensive public safety systems sits a dispatcher without the appropriate tools or instruction.

The dispatcher occupies an essential role in EMS, deciding how, who, when, and even whether to respond. In systems where these decisions are made by trained dispatchers correctly using medically supported tools, responses are justified and resources are effectively managed, but in systems where the old way is still the only way, medical, ethical, fiscal and potential legal problems are widespread.

In this era of tight budget control, are EMS managers making the most efficient use of their human and material resources in dispatch and response? A recent report revealed that fewer than 50% of the fire departments surveyed had any form of EMD system in place, and many of those that do are likely to be using outdated or ineffective methods.

If the fire service is to continue to meet the challenges looming on the horizon, it must accept that a valid and effective EMD protocol, applied in an appropriate and consistent manner, is a pivotal part of this system.

Many fire-based EMS agencies have implemented a sophisticated dispatching program in response to the growing medical service demand and the pressing need to prioritize requests for service. The Medical Priority Dispatch System has allowed these agencies to meet the rising public demand for EMS by making the most efficient and effective use of existing EMS resources. A valid dispatch protocol, combined with appropriate training, unified EMD standards, National Academy of Emergency Medical Dispatch certification, and the publication of voluntary medical dispatch standards by national health care organizations has further defined medical dispatch standards.

Key questions and emergency response

The EMD protocols, which form the core of the MPDS, consist of a universal entry-level protocol, 32 chief-complaint (incident-type) protocols and eight prearrival instruction protocols. The case-entry protocol is the dispatcher's equivalent of the EMT's primary survey, while the chief-complaint protocols are the dispatcher's equivalent of the EMT's secondary survey. Each chief-complaint protocol categorizes a frequently presented complaint and provides for a medically appropriate set of preplanned questions, locally determined preplanned responses and medically appropriate instructions to the caller.

The MPDS protocols eliminate the pitfalls of diagnosis-oriented dispatch commonly seen in many public safety agencies throughout the world. Traditionally, many fire service agencies have allowed a medically untrained dispatcher to "diagnose" the caller's chief complaint or reported problem as the initial step in the resource-allocation process. This has proved to be medically as well as legally unsound.

Diagnosis is the most complex of all medical tasks. For a typical chief complaint, such as chest pain, there are hundreds of potential underlying causes. It's therefore neither reasonable nor medically appropriate to allow the dispatcher to diagnose the caller's chief complaint or problem, and it's even less reasonable to accept the caller's diagnostic opinion as a basis for subsequent dispatch and response-based activities.

In the MPDS protocol, each call is immediately evaluated through a programmed, medically approved interrogation sequence that uses pre-determined, fully scripted key questions to assess the severity of the chief complaint or incident type. The chief complaint, age, consciousness and breathing status (the four commandments of EMD) are determined, and if appropriate, a dispatch is made immediately.

Response determinant code

The dispatcher is then directed to verify the need for dispatcher intervention. If it's determined initially that the patient is breathing, the appropriate chief complaint or incident-type protocol is selected and the emergency medical dispatcher then continues the interrogation for about 30 more seconds by asking an average of four or five key questions per protocol. These questions have been medically determined as the minimum amount of interrogation necessary to adequately establish the Response Determinant Code, not a diagnosis.

It's important to understand that these RD codes reflect medical "statistical probability" within different preplanned levels of response. For example, in many MPDS response grids, chest pain wouldn't evoke the same preplanned level of response in a 10-year old patient as in a 57-year old.

These RD codes are the dispatch equivalent of the hospital diagnosis-related groups that are used to bill for medical incidents. While RD codes are universal, the local responses linked to these codes are assigned by the user agency. Such unit response groups will reflect an agency's available response configurations. These response assignments are both medical- and fire suppression-unit management decisions and should be studied carefully and made in conjunction with medical control during MPDS implementation.

A rational response

Many dispatch agencies send the closest available first responders and ALS paramedics on all medical calls. Many still require the use of lights and siren en route to the scene for all accidents. Some still use lights and siren on all transports. This maximal response philosophy is claimed to give those in dire need the closest help immediately and ALS help as quickly as possible. In most incidents, however, this is misguided. The MPDS allows a rational transition away from this wasteful philosophy.

It has been proven safe, and medically correct, to dispatch less than an ALS paramedic on many EMS incidents, and to drive without lights and siren not only during transport but also during initial response. That the majority of medical service requests aren't for time-critical, life-threatening medical emergencies justifies this approach.

A system that dispatches lights-and-siren ALS responses to all calls is at risk, because at some point it will be unable to provide a timely ALS response to a genuine ALS emergency. Dispatch-savvy attorneys now know this and will inquire about system deployment decisions before the call in question. In addition, with EMS vehicle-related collisions in North America estimated into the tens of thousands, it's unsafe to require a lights-and-siren response on all accidents. This practice exposes crews to the additional hazards of a full emergency response, just to arrive one or two minutes earlier for non-critical patients.

In FIRE CHIEF's 1992 survey of fire departments that used some form of the EMD process, only 50% responded that they use EMD to decide on whether ALS or BLS units should be dispatched. (See "EMD in the fire service," May 1992, available at .) Even though 50% do use the EMD process to decide on the capability of the responding unit, 44% reported that they use it to separate emergency from non-emergency calls and only 34% indicated that it was used to determine the most serious emergencies. Clearly, to be consistent and to maximize resource use, the emergency medical dispatcher must have tools that allow emergency calls to be allocated appropriate resources and response timeliness (emergency versus non-emergency and identification of the most serious).

Dispatcher training

Emergency medical dispatchers have a unique set of duties and responsibilities in the EMS world. Their training should therefore be significantly different from that of field EMS providers. Many fire departments require a minimum of a medical dispatch course for their dispatchers, and some require firefighter, first responder or paramedic training. Many departments maintain their own training programs.

There are problems with both of these approaches. Firefighter, first responder or paramedic training is only partially relevant, and in-house programs often lack consistency and appropriateness. Many departments, though reminiscent of the situation across the board some 30 years ago, still require no training for their dispatchers.

Formal dispatcher training in the MPDS has been initiated in many fire departments in the United States and other countries. The anchor for this training is NAEMD's EMD certification program.

To safely, competently and effectively use the MPDS protocols, dispatchers must understand their underlying philosophy and be carefully trained in their specific use. An academy-approved certification curriculum has a brief review of objectives and basic telecommunications principles. The role of the emergency medical dispatcher is defined and the MPDS concepts are discussed in detail. Students are taught the system's four core components, including Case Entry, Key Questions, Post-Dispatch and Pre-Arrival Instructions, and Response Determinants.

The four commandments of medical dispatch are reinforced as basic interrogation elements that must be obtained and relayed to respondents on every call. In the subsequent Key Question component, the importance of identifying the presence or absence of priority symptoms, which are defined in the MPDS as chest pain, difficulty breathing, changes in level of consciousness or severe hemorrhage, is emphasized. The answers to the Key Questions then lead to appropriate phone-directed dispatch life support instructions and also establish the correct (standardized) level of emergency medical response. While an immediate and/or maximal response is permitted "when in doubt", the number of such doubtful situations is greatly reduced by properly complying to the MPDS protocols.

An important learning experience for trainees, and a highlight of the academy's certification course, is the introduction of the non-lights-and-siren response concept for many EMS calls previously responded to as "dire emergencies." After an explanation that abdominal pain and fever in a 17-year-old male with appendicitis donít constitute a prehospital medical emergency and requires neither a lights-and-siren nor an ALS/paramedic response, EMD students often respond, "Why, after all these years, haven't we been told that before?"

Prearrival care

The concept of dispatch life support essentially encompasses the intervention process of a trained dispatcher with an emergency caller. The National Association of EMS physicians defines DLS as "the knowledge, procedures, and skills used by trained dispatchers in providing care through prearrival instructions to callers. It consists of those BLS and ALS principles that are appropriate to application by medical dispatchers."

Many fire departments believe that telephone assistance to the patient via the caller is an important part of EMD. This importance is evidenced by the statistic that, in the 1992 survey, more than 70% of those departments that had an EMD system in place used it to provide callers with prearrival instructions to "prevent any further injury through bystander Good Samaritan actions." The provision of on-line telephone instructions should be an integral part of any EMD system, and the NAEMSP has stated in both its 1988 consensus document and its 1989 position paper on emergency medical dispatching that "Pre-Arrival Instructions are a mandatory function of each EMD in a medical dispatch center."

These instructions aren't only an essential element of the MPDS, they're a logical requirement and a moral necessity in emergency medical dispatching. To prepare for the role of providing instructions to the caller, dispatchers are trained in dispatch life support. The DLS instructions that MPDS-using emergency medical dispatchers provide to callers cover a variety of first responder and maintenance techniques. These range from basic head-tilt airway maintenance and hemorrhage control to more involved procedures, such as the Heimlich maneuver, phone-instructed CPR and emergency childbirth assistance.

The specific treatment sequences for choking, arrest and emergency childbirth are commonly called prearrival instructions, because they represent potentially life-sustaining DLS medical instructions for the dispatcher to relay before the on-scene arrival of field personnel.

In addition, the MPDS includes several basic instructions called Post-Dispatch Instructions that are meant to be relayed after units are dispatched. PDIS include turning off power sources around an electrocution victim, getting out patient medications and putting protective family dogs away. In most instances, PDIs also include instructions for maintaining a patient's airway, breathing and circulation.

MPDS and fire-based EMD

What results can a properly implemented and functioning MPDS deliver to the fire service? Implementing the MPDS provides effective resource utilization, reduces dispatch liability risks, ensures quicker EMS intervention through DLS and reduces the workload of other EMS resources. Additionally, quality-assurance and risk-management processes provide statistics regarding overall call severity, incident frequency and distribution, the dispatcher's performance, and MPDS protocol compliance.

Training and academy certification eliminate the need to assign EMT or paramedic personnel to perform medical dispatching functions. The call evaluation and prioritization provided by certified dispatchers is more standard and consistent than the free-form call evaluation performed by medical professionals and is comparable to the SOPS followed by police, firefighters and paramedics.

The MPDS also has positive effects on the system's bottom line. In terms of time and money, the 24-hour basic EMD certification course is less expensive to provide than EMT training, which has been proved over time to be less practical to the EMD. The overall cost savings of the MPDS are often substantial, as a result of more appropriate EMS resource utilization, reduced medical dispatch litigation, and significant reductions in both vehicle maintenance and collisions.

There are now thousands of public safety agencies using identical versions of the MPDS. A growing number of prominent and sophisticated dispatch centers have been recognized by the academy as Accredited Centers of Excellence.

The goal of the MPDS is, in essence, "to send the right thing(s), in the right way, at the right time, in the right configuration, and to do the right things until the troops arrive." Some areas where a properly initiated MPDS has demonstrated proven positive effects are:

  • Decreased liability exposure,
  • Decreased response time to zero minutes (through DLS),
  • Decreased emergency medical vehicle collisions,
  • Decreased lights-and-siren runs, Ŗ Improved medical control at dispatch,
  • Improved dispatcher professionalism and morale,
  • Improved relationships between dispatch and field-response personnel,
  • The introduction of continuing medical education in the dispatch center,
  • Increased quality of the employee,
  • Increased defensibility of dispatcher actions and employee standards,
  • Increased standardization of care and medical dispatch decision-making,
  • Increased resource availability (especially ALS),
  • Increased safety of response personnel at the scene,
  • Increased en route information to response personnel, and
  • Increased cooperation with associated public safety systems, law enforcement and ambulance services.

Implementing MPDS A sound implementation strategy is the key to successfully establishing an efficient MPDS. The implementation process should include operations managers, EMS managers, dispatchers, field and private providers, training personnel, and physician medical control. Planning, such as timetables for training and start-up, should be preset and involve a phased implementation scheme to optimize the process, and each step of the implementation should be clearly defined.

For many fire service systems, assigning local responses to each of the MPDS response determinants will require a justification of existing response modes. This is the time to review and revise out-dated policies that call for full emergency response to all incidents.

Finally, without sound quality assurance and improvement, a new medical dispatch program or even an older, poorly functional system is destined to remain an event rather than a healthy, sustained process. The EMS literature has clearly stressed the importance of having uniform practice standards, such as quality-assurance elements in dispatch.

Some of the key components of a medical dispatch quality-assurance and improvement program are initial emergency medical dispatcher training, certification, continuing dispatcher education, protocol compliance data generation and medical dispatch case review. Each of these elements involves developing predefined standards against which performance can be objectively measured. These performance measurements are intended to provide feedback and objectively quantify both the medical dispatch process, and the outcome of the dispatcher's activities.

In the pipeline

Major changes, which will be of increasing importance to all dispatch agencies, are beginning to affect EMD. Alternatives to traditional 911 services will make the process of appropriate dispatch an increasingly complex operation requiring high levels of reliable and reproducible triage and increased efforts to coordinate access to health care services.

Changes in funding and payment, largely driven by cost-cutting measures that are an unavoidable part of managed care, will also have enormous effects on all aspects of EMS. The MPDS pre-emptively overcomes the problems that these changes are likely to cause in other systems.

In FIRE CHIEF last year, Chief Dennis Murphy described a system called mobile health services. (See "The ABCs of MHS," January 1998, available at .) MHS has the goal of "redirecting non-emergencies away from 911 and emergency systems and into more appropriate and less expensive non-emergency treatment modes."

Our experience is that many healthcare providers, primarily HMOs, are already using a range of alternatives to traditional 911 services. Many are dissuading callers from using 911 by creating alternative access points or by denying claims when inappropriate transport was provided.

It appears inevitable that MHS and other related alternatives to traditional EMS and ambulance transport roles will necessarily become a sub-component of the EMS system. But it seems unlikely that a potential emergency caller will waste valuable time calling a seven-digit or 800 number rather than 911. Instead it will fall to the 911 dispatcher to triage calls into true medical emergencies and non-emergency calls, which will be carefully handed off to other modes of health care. It's clear that a unique feature of the MPDS will play an increasingly pivotal role in this more complex call handling.

Protocols vs. guidelines

While the smooth integration of a variety of resource responses will benefit the patient, the MPDS is also a dispatch protocol that can influence the dispatch agency's bottom line. The Health Care Finance Administration recently proposed changes in the rules that relate to the reimbursement of ambulance transport charges. HCFA has proposed that ambulance reimbursement be tightly linked to the patient's medical condition as described by the ICD-9 code.

This seems perfectly reasonable, until you realize that the basis for need will be determined after the fact by the admitting physician. So if you transport a patient or recommend transport of a patient incorrectly, you won't get paid! This is a good reason to review the essential differences between a systematized, scripted EMD protocol (such as the MPDS) and a set of arbitrary, variably applied guidelines.

Guidelines act as a series of interrogation prompts that the dispatcher can follow if he or she desires. Two callers who have exactly the same situation and information in all likelihood won't be asked the same questions, and thus the resulting response mode will depend entirely on the dispatcher's skills and experience. If the dispatcher makes a decision for an ambulance transport and the admitting physician agrees, the transport will be reimbursed. If the admitting physician disagrees, it probably won't. It's a little like going to the office and doing what you think your boss wants you to do, hoping that you'll get a paycheck at the end of the month.

The same two callers interrogated by dispatchers using the MPDS, would be asked exactly the same questions, in exactly the same order and in exactly the same way. This leads to a consistent and reproducible resource response, because the MPDS is presumptively classifying each patient based on information that's systematically and correctly collected from the caller. In the same way that medical oversight currently justifies the resource response for a given determinant code at the time of MPDS installation, these responses can be tailored to the precise requirements of the people who ultimately foot the bill.

So when the MPDS recommends a response, you know at the moment of dispatch that the response has been pre-approved by medical oversight, has also been pre-approved by financial oversight, will be appropriate for the patient and will be paid for. The implications for correct patient care, cost reduction by managed care, effective use of limited resources by the responding agency and the fire-based dispatch agency's bottom line are enormous.

If the fire service and other public safety agencies are truly committed to the quest to provide efficient care and customer service to the citizens they serve, continual reassessment of the dispatch system's role is necessary to plan for the increasing demand. As profound and all-encompassing changes drive new priorities and efficiencies in health-care systems, your dispatch system will be the key to responding to new circumstances and integrating new paradigms into fire-based EMS. Comprehensive use of MPDS within the fire service is an important step in maximizing the efficient use of our human and material resources in the providing high-quality, safe, economical and effective patient care.

Contact Information

For information on the Medical Priority Dispatch System, contact the National Academy of Emergency Medical Dispatch, 139 E. South Temple, Salt Lake City, Utah 84111; 801-359-6916, fax: 801-363-9144, .

Widely recognized as the "Father of EMD," Jeff Clawson, M.D., founded the National Academy of EMD and invented the Medical Priority Dispatch System. Geoff Cady, EMT-P, is an EMD and EMS Pathways consultant with over 20 years of experience. He is currently chair of the Call Processing Board for the NAEMD. Bob Sinclair, Ph.D., has over 15 years of experience in scientific research and is senior technical editor and research specialist for the NAEMD. Robert Martin is a marketing and communications specialist. He is executive director of the NAEMD, where he has worked for the past 11 years.