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 does not match the history, physical exam, or diagnostic test results. Go back to the patient assessment and reformulate a working plan.
Conclusion
Although some may consider patients with undifferentiated conditions difficult or frustrating problems to manage in the prehospital setting, others may find them to be a complex challenge. EMS clinicians must approach such patients with the same degree of consistency they do for other clinical situations, such as trauma or cardiac arrest. Pursuit of medical inquiry coupled with knowledgeable clinical decision making lead to optimal EMS courses of care and successful transitions to subsequent care teams. There is no single model of clinical decision making that adequately relates to the very complex prehospital environment. EMS clinicians should be familiar with tools and techniques they might apply, and the nature of errors they might potentially commit. With this awareness, they might enhance patient care, avoid errors, and improve patient safety.
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