A city bus involved in a low-speed, rear-end fender-bender has to be high on the list of top EMS nightmares. Forty people are on the bus. Some have true injuries; a few saw the attorney's commercial on television the night before and have neck pain exacerbated by the fact that the other vehicle was a Mercedes; most just want to get on with their day. A two-person EMS crew arrives on scene. Besides the EMS crew with the nervous breakdown, who are the actual patients?
The definition of an EMS patient is vital. Not only does it determine the volume of run reports we complete, it underlies more basic issues. For whom does EMS respond and why? Is there always a duty to treat and transport? Can we assess some patients and let them go? How we define an EMS patient determines the operation of our entire prehospital system.
So let's start with the basics. Who or what is an EMS patient? One way to define an EMS patient is to use positive characteristics or descriptors that indicate a patient belongs in the EMS system. For the sake of simplicity, we'll consider a single emergency condition as the focus of this EMS system. After exploring this single example, you may see how the same principles apply to the whole gamut of emergent, urgent and non-emergent conditions.
Assume we are working with an EMS system whose sole reason to exist is to care for patients with chest pain of cardiac origin. In this system, patients are positively defined as "persons who present with signs or symptoms potentially related to cardiac ischemia or myocardial infarction." So if we were to define a patient within this EMS system, we might start by saying our patients are those with substernal, pressure-type chest pain that radiates to the neck or shoulders and is associated with sweating, nausea, vomiting and shortness of breath.
Even the most inexperienced EMS providers would quickly recognize that a small fraction of patients with true coronary insufficiency have all the classic complaints. So let's make our definition more expansive and define our patients as having chest pain associated with nausea, vomiting, shortness of breath or diaphoresis. That should cover a lot more people.
But patients with cardiac problems don't always present with substernal chest pain. Maybe the pain is located in the back or only occurs in the neck or the arm. Maybe it's located in the epigastric area and described as "indigestion." Maybe the pain is not even associated with any of the classic accompanying factors. So to ensure the net is spread wide enough to encompass all patients at risk, my patient population now includes all people with chest, neck, shoulder, upper back or epigastric pain, as well as those with dyspnea, diaphoresis, nausea or vomiting.
How about other symptoms? Cardiac ischemia may cause arrhythmias, so we should include anyone with a fast, slow or irregular heartbeat as a patient in our system. In older people, unsuspected infarction may cause acute mental status changes, and patients with diabetes often have "silent MIs" with atypical or minimal symptoms.
As we continue to recognize clinical exceptions to the classical picture of our cardiac population, the group of patients to whom we respond grows wider and wider until we find ourselves responding to virtually any call for help. If we extend this analogy to an entire EMS system caring for the entire range of patients, we find positive criteria become almost useless, and those few cases where no potential emergency exists become so infrequent they are difficult to recognize.
We might also approach defining the patient by negative characteristics or by saying what the patient is not. Let's go back to our cardiac EMS system. Our positive criteria define our patients as anyone with chest, neck, shoulder, upper-back or epigastric pain, as well as those with dyspnea, diaphoresis, nausea, vomiting, altered mental status, all diabetics and (with a bow to Yul Brenner) etc., etc., etc.
By contrast, negative criteria might indicate "a person with no signs or symptoms that might refer to cardiac ischemia is not a patient." This form of the definition allows us to spread the net quite wide, though still excludes patients whose illness or injury bears no potential links to the cardiovascular system. In a larger sense, the use of negative criteria to define a patient creates a manageable set of decision rules.
This discussion is not just academic. During my tenure as medical director in Volusia County, Fla., we ran circles around the issue of who was an EMS patient and who required EMS run report completion until we fell upon the idea of using negative criteria. In our system, an adult for whom EMS has responded who denies illness or injury, presents with no signs or symptoms of illness or injury, has a minimal or absent mechanism of injury and appears competent to decline EMS services (as set down by a separate section of protocol) may be considered not an EMS patient. Paramedic or EMT discretion may override the above criteria at any time in favor of complete assessment and care; an EMT or paramedic may not omit completion of the run report, with provision of full assessment and care, under any other circumstances.
Using negative criteria still forces the attending EMT or paramedic to assess the patient to verify all the "disqualifying" criteria are present. The criteria themselves ensure compliance with appropriate prehospital standards of care. The system doesn't require the provider to complete a run report on "non-patients," but because patient assessment does occur, I strongly advise some sort of internal agency documentation.
This compromise works for us and presents a minimal risk of missing a truly ill or injured patient. The one thing it does not do is relieve the EMT or paramedic's workload (which, if truth be told, I suspect is the reason the definition of the "non-patient" is such a dear issue to EMS personnel). If a patient has a complaint and wishes care, care is still provided, whether or not the complaint is truly an emergency condition. This policy doesn't allow the provider to make the determination of whether the patient needs care or not. Most providers have yet to recognize that fire, police and EMS are really in the business of customer service. The use of negative criteria allows everyone who wishes care to receive it and still honors the wishes of those asymptomatic patients who desire no interventions.