In 2009, the American College of Emergency Physicians (ACEP) stated that “[t]he term ‘Excited Delirium’ has been used to refer to a subcategory of delirium that has primarily been described retrospectively in the medical examiner literature.”[25] Most EMS health professionals regard ExDS as a medical condition bearing the hallmark of excessive agitation as a symptom that, if left untreated, may result in sudden death.[26] The diagnosis has also been used to explain injury or death to individuals in police custody. The ACEP, the American College of Medical Toxicologists (ACMT), and the National Association of EMS Physicians (NAEMSP) recognized the existence of Excited Delirium Syndrome. However, the ACEP has recently shifted its position to recognize hyperactive delirium with severe agitation as “a life-threatening medical condition that demands emergency medical treatment.” [27 (p. 2)]
In Colorado, the EMPAC has provided guidance to EMS medical directors who are seeking a waiver for ketamine use for excited delirium and/or extreme or profound agitation. See Appendix G. The most recent guidance characterized ExDS as a “presumptive diagnosis;” it is described in one guidance document as: “Excited Delirium Syndrome: These patients are truly out of control and have a life-threatening medical emergency [sic]. [T]hey will have some or all of the following sx: Paranoia, disorientation, hyper aggression, hallucination, tachycardia, increased strength, hyperthermia.” (See Appendix G, Agitated/Combative Patient Protocol)
Delirium is a psychiatric diagnosis that, along with its hypoactive and hyperactive manifestations, is recognized by the Diagnostic and Statistical Manual of Disorders (5th ed.)(“DSM-5”). However, ExDS is a disputed diagnosis that is not recognized as a legitimate medical diagnosis in the DSM-5. Neither is ExDS uniformly recognized as a legitimate medical diagnosis by some leading professional medical organizations. For example, the American Medical Association (AMA), World Health Organization (WHO), and the American Psychiatric Association (APA) do not recognize ExDS as a valid medical diagnosis.
A council of the AMA that was tasked with researching the use of drugs to chemically restrain agitated individuals outside of hospital settings characterizes the ExDS diagnosis this way:
“Although it is extensively used in academic and medical literature, considerable debate exists in medicine about how to characterize ExD and ExDS, if they even exist, and how ExD contributes to sudden death. The pathophysiologic mechanisms of ExD have not been elucidated and ExD does not currently have a known etiology. However, ExD has been characterized in the literature by delirium, agitation, acidosis, and hyperadrenergic autonomic dysfunction, typically in the setting of drug use or serious mental illness or a combination of both.”[28 (p.3)]
The AMA council notes that the population of people who are diagnosed as ExDS patients are predominantly men in their mid-30s who are agitated. Further, it notes that “despite similar rates of drug use across race and ethnicity in the United States, epidemiological studies show that it is specifically and disproportionately younger Black men who use cocaine and other psychostimulants and are in police custody that are at highest risk for death from ExD/ExDS.”[28 (p.4)] The men who are most likely to die of ExDS are described as “aggressive, impervious to pain, and display bizarre behavior.”[29] The AMA council relies upon studies to declare that “mortality rates associated with ExD/ExDS have been reported to be between 8 to 16.5 percent.”[28 (p.4)]
By all indications, ExDS lacks a consensus definition, a specific diagnostic test, clearly understood pathophysiologic mechanisms, and verifiable clinical indications that can be applied to reach a reliable diagnosis. Even organizations that recognize the diagnosis concede that the unique indications assigned to ExDS are difficult to specify since the characteristics of the syndrome overlap with many other clinical diseases. To complicate matters, the medical community can neither clearly classify the cause[s] of the syndrome nor provide a coherent explanation as to why ExDS may lead to sudden death. In fact, forensic pathologists and coroners have assigned ExDS as a cause of death when other existing conditions are not readily apparent. Relevant professional organizations disagree whether an ExDS diagnosis can only be confirmed post-mortem.[25,28] Compounding all of these difficulties are the facts that these diagnoses are exceedingly rare, are usually dependent on subjective descriptions of the patient’s symptoms, and almost always fail to recognize the contribution of physical restraint and positional asphyxia as potential contributors of death in these lethal situations.[28, 30]
A medical diagnosis that lacks a uniform definition, underlying scientific evidence, diagnostic testing, verifiable clinical indications, and a clear understanding of its causes can lead to mistaken assessments and misdiagnoses. But the panel concludes that the far worse consequence is that the utilization of a contested diagnosis in a structurally inequitable health care system has disproportionately harmed and impacted marginalized communities and people of color. The continuing use of this amorphous and unverifiable diagnosis in the prehospital field will only serve to disadvantage these populations further. The panel recommends discontinuing the use of the ExDS diagnosis in an effort to abate its adverse consequences, including the unnecessary and disproportionate administration of ketamine to marginalized populations.
The panel also recognizes that the medical community may at some point be able to validate the diagnosis of ExDS with supporting scientific evidence that provides a clear understanding of its cause, identifies verifiable clinical indicators, and establishes validated screening criteria and diagnostic testing. Should that occur, the medical community may be able to reach consensus on a uniform definition of the ExDS diagnosis that is stripped of bias and negative implications.
Recent Studies on Ketamine Use by Race/Ethnicity
Law Enforcement Influence on Ketamine Use
Appropriate Administration of Ketamine