assessment and a prehospital 12‐lead ECG. The following strategies can also be used to improve the clinical decision making for use of diagnostic tests [7, 9–11].
Employ any readily available decision‐making algorithms or decision rules. A classic example is the Ottawa Ankle Rules, which help emergency physicians in deciding on ordering ankle x‐rays for injured patients. Although there are very few clinical guidelines in practice for the out‐of‐hospital setting, with the increasing body of evidence, these will increase in the future.
Use existing prehospital protocols for specific therapeutic decisions whenever possible.
Use only those tests that will affect the disposition or treatment of the patient by confirming or excluding the disease hypothesis at hand.
The truly Undifferentiated Patient
The patient whose condition remains truly undifferentiated after the aforementioned maneuvers requires the same degree and level of care as those patients who have clear prehospital diagnoses. To further facilitate the care of the patient, it is important for the EMS clinicians to advocate for the patient and relay their findings and concerns to the receiving facility. The hospital staff in turn can then continue to optimize the patient interaction to identify and meet patient needs.
Transition of Care to the Receiving Facility
Just as the transition of care from the dispatcher to the paramedic occurs, there is also a transition of care between the EMS clinician and the hospital ED. It is tremendously important that this hand‐off process maintains and facilitates the continuity of patient care and does not jeopardize patient safety. EDs commonly experience the difficult situation of overcrowding and resultant long turnaround intervals for EMS staff. When EMS personnel arrive with a patient with no priority symptoms and no identifiable chief complaint, this may lead to confrontation between the charge nurse or physician and the EMS personnel. Moreover, this may lead to the receiving ED triaging the patient to the waiting room or to a lower priority than is appropriate. If the patient’s condition is truly deemed undifferentiated, then the EMS clinician must clearly state this to the receiving ED and must elaborate on what has been done to optimize the history and physical exam, and provide insight and recommendations for next steps.
Consequences of an Undifferentiated Condition
There may be no significant consequences to either the patient or EMS personnel when the patient’s condition is undifferentiated. The patient may have an uneventful EMS and ED experience. The main frustration is that both the EMS crew and the patient are left with perhaps an unsatisfactory health care transaction. However, it is also possible that these patients may be subject to increased medical error and potentially compromised patient safety due to undifferentiated diagnoses.
Error in all aspects of medicine has become an international issue with the landmark publications of the Institute of Medicine report To Err is Human and several other large studies, including the Harvard Medical Practice Study, the Colorado‐Utah Study, the Quality in Australian Healthcare study, and the unanticipated death post‐ED discharge study [12–16]. In the Institute of Medicine report, error is defined as the failure of a planned action to be completed as intended or the use of a wrong plan to achieve an aim [12]. All these retrospective studies, which evaluated patients admitted from the ED, found surprisingly high rates of medical errors, many of them originating in the ED, and most of them preventable. There have been no large prospective studies describing error in the prehospital environment. However, there have been no reported associations between patients with undifferentiated conditions and the risk of medical error.
There are several ways of classifying clinical errors, which in turn provide a means of reducing or preventing these errors [10, 11, 17]. A common way is to classify them based on the models of cognitive performance or clinical decision making. These include skill‐based errors, generally known as slips, or a failure in the execution of an action sequence, and lapses, or a failure of execution when the action was not the intended action. Rule‐based errors are mistakes when the wrong rule is chosen due to misperception of situation or the rule is misapplied. Knowledge‐based errors occur when there is lack or misapplication of knowledge, or misinterpretation of knowledge [10, 11, 17]. An alternative approach is to categorize errors into procedural errors (intravenous starts, intubations, and such), cognitive errors (any error in the course of diagnosis, management, and disposition of patients), and affective errors (the emotional state of the EMS clinician unduly influences the clinical decision‐making process) [10, 11, 17].
An alternative to categorizing errors is to overlay the clinical decision sequence of events that occurs when a patient is seen. For example, the progress of a patient through the prehospital phase of care is driven by multiple decisions underlying the sequence of patient assessment, diagnosis, treatment, and disposition [18]. Many experts feel that the largest weighing or pivotal feature in this sequence is the diagnosis and its associated clinical decision making. There are three commonly described sources of diagnostic error: no‐fault, system, and cognitive [10, 11, 16]. No‐fault errors can be related to a variety of factors focused mainly on the patient. These include situations in which the history is atypical or undifferentiated; patients who are confusing, inaccurate, uncooperative, or non‐compliant; and patients who misrepresent their conditions. System diagnostic errors result from a large variety of error‐producing conditions (e.g., multiple interruptions, stress loads, busy shifts), equipment failure, and organizational failures. Cognitive diagnostic errors, as the preceding discussion reflects, are any of the errors related to line of medical inquiry.
Diagnostic error, such as misdiagnosis, can result in an incorrect choice of therapy, failure to use an indicated diagnostic test, misinterpretation of test results, and failure to act on abnormal results. These, in turn, may lead to patient harm in the form of incorrect treatment protocols, incorrect destination choices, and risks of no transfer.
Strategies for Minimizing Errors in Clinical Reasoning
EMS clinicians can limit errors in their clinical reasoning by recognizing the potential biases that may be present and incorporating certain strategies or heuristics. The science and evidence around heuristics, clinical decision making, and reasoning are in relative infancy and require EMS clinicians to extrapolate from the current and evolving evidence regarding the heuristics of decision making in medicine and emergency medicine, which may include the following [6]:
Many experts will avoid using a previous diagnosis to influence their current diagnosis – collect a history, conduct a physical exam, employ strategic diagnostic tests, and use clinical knowledge to formulate a diagnosis and management plan.
Minimize the influence of personal or external biases (e.g., an overzealous partner or other health care practitioner) on clinical decision making.
Check for critical items in the past medical history or risk factors for serious disease.
Pay particular attention to the vital signs of the patient.
Avoid premature closure if the diagnosis is uncertain or undifferentiated.
Be careful of high‐risk environments and times, such as high‐volume and high‐acuity times of day, and personal and emotional fatigue.
Be careful of high‐risk patients – refusal of care, abusive/hostile/ violent patients, confrontational and annoying patients, and those with drug intoxications or psychiatric disease.
Be careful of situations in which the presumptive diagnosis
