By Andrew Pachon, MD; and Tiffany M. Abramson, MD
911 Dispatcher: “911, What is your emergency?”
Citizen: “We need help now. There is a 20- to 30-year-old guy running around naked into traffic! He is threatening everyone … yelling one second and laughing the next … he isn’t making any sense. We are all very scared.”
Who does the 911 dispatcher send? Law enforcement? EMS? Both?
EMS and law enforcement personnel have seen an increase in calls for service involving psychiatric complaints in recent years. Notably, incidents with agitated erratic individuals, whether due to an underlying psychiatric process and/or polysubstance abuse, are high-risk incidents for all parties involved. These individuals have collectively been labeled as being in a state of agitated delirium or excited delirium.
The City of Long Beach has taken an integrated approach to responding to these types of incidents. In January 2021, the city implemented the Long Beach Integrated Medical Intervention Response Pilot Program (IMR), which utilizes a dual dispatch of fire and police personnel for incidents where excited delirium is suspected. This unique pilot program reinforces the importance of first responders from different agencies working together to address very complex and high-risk situations.
History of excited delirium
Delirium is a complex syndrome that affects a person’s orientation, memory, thought process, consciousness, perception and behavior.  A unique subset of individuals experiencing delirium exhibit erratic behavior and an extreme fight-or-flight response by the nervous system, labeled as excited delirium (ExD). 
Cases of ExD were first described in the mid-1800s, but it was not until 1985 that the term “excited delirium” was first published in reference to cocaine-induced psychosis.  Since that time, excited delirium has become common vernacular to describe individuals who are agitated, hyperaggressive, displaying bizarre behavior, tachycardic and hyperthermic.
First responders and emergency medicine physicians experience firsthand the challenge of caring for these patients during the acute phase of agitation that is characteristic of ExD.
In 2009, the American College of Emergency Physicians (ACEP) formally recognized excited delirium as a unique syndrome.  However, in December 2020, the American Psychiatric Association (APA) released a contrary position statement refuting ExD.  They expressed concern that the proposed criteria for diagnosis were too non-specific and encouraged jurisdictions to “develop, implement, and routinely update evidence-based protocols for the administration of ketamine and other sedating medications in the emergency medical contexts outside the hospital.”
Regardless, patients who experience this condition are at a higher risk of injury and death. Tragically, ExD patients have a fatality rate of approximately 10%, with 75% of those deaths occurring on scene or during transport. 
Excited delirium: Pathophysiology
The exact pathophysiology which leads to ExD is unclear as it is likely multifactorial.  Stimulant use (cocaine, amphetamines, etc) is often observed in conjunction with ExD. It is hypothesized there is a dysfunction of the control of the sympathetic nervous system . This contributes to excessive dopamine levels in the brain, which leads to the profound hyperthermia observed in ExD patients.  A reflexive tachycardia and tachypnea are stimulated, leading to a significant acidosis via muscle stimulation. This muscle activity causes tissue death and elevated creatine phosphokinase protein within the blood and ultimately, rhabdomyolysis.  Finally, the resultant metabolic acidosis can lead to hyperkalemia, which can induce fatal arrhythmias, including QT prolongation, bradycardia and asystole. 
Recognizing excited delirium
In addition to the above signs of ExD, Dr. Michael Curtis, an emergency physician and EMS medical director, has developed the mnemonic, “NOT A CRIME” to identify symptoms of excited delirium: 
N: The patient is Naked and sweating from hyperthermia
O: Objects, especially glass, are targets of violence
T: The patient is Tough and unstoppable, with superhuman strength and insensitivity to pain
A: There was Acute onset: witnesses say the patient “just snapped!”
C: The patient is Confused regarding time, place, purpose and perception
R: The patient is Resistant and won’t follow commands to desist
I: The patient exhibits Incoherent speech, often with loud shouting and bizarre content
M: Mental health conditions are evident and/or make you feel uncomfortable
E: EMS should request early backup and rapid transport to the ED
Treating excited delirium
First responders must recognize ExD patients are experiencing medical emergencies and are not simply non-cooperative suspects.  A review of the use of force with excited delirium patients has shown that standard de-escalation tactics are likely to be ineffective. ExD patients are often described as “impervious to pain” and therefore pain compliance techniques, including distraction strikes and/or use of a TASER device, are infective. As outlined above, these patients are predisposed to hyperthermia and muscle breakdown and therefore, physical restraint alone is likely to be ineffective and further exacerbate these conditions as the patient continues to fight against restraints.
In October 2020, the National Association of EMS Physicians (NAEMSP), National Association of State EMS Officials (NASEMSO), National EMS Management Association (NEMSMA), National Association of Emergency Medical Technicians (NAEMT) and American Paramedic Association (APA) issued a joint statement that the primary of goal in treating patients exhibiting excited delirium is the “importance to protect agitated, combative or violent patients from injuring themselves while simultaneously protecting the public and emergency responders from injury.”  They provided recommendations for training, restraints, pharmacologic management and the importance of reassessment.
The mainstay medical treatment for patients exhibiting excited delirium is pharmacological management of symptoms. It serves to decrease the fight-or-flight response and avoid further harm to both the patient and emergency personnel. Traditionally, benzodiazepines are first-line agents for use in the field and in the emergency department.  Additional options include first-generation antipsychotics (e.g., haloperidol, droperidol), second-generation antipsychotics (e.g., ziprasidone, olanzapine) and ketamine. 
Regardless of the method of pharmacological management, medical staff must be cognizant of the side effects and be able to provide advanced life support, including advanced airway management, cardiac/medical monitoring and resuscitation. Benzodiazepines may induce respiratory depression and have a slow onset of effectiveness; therefore, caution is needed in redosing to prevent over-sedation. Antipsychotics can induce prolonging of the QT interval, which may result in fatal dysrhythmias. Lastly, ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, may result in increased oral secretions and laryngospasm, and worsen agitation in what is termed “emergence phenomena.” Medical personnel should also evaluate for concomitant etiologies of the current condition (e.g., hypoglycemia, infection, trauma) while providing supportive measures. Given the high incidence of mortality, the excited delirium patient should be rapidly transported to the emergency department for further evaluation and management.
Long Beach Integrated Medical Intervention Response Pilot Program
After extensive planning and training, the Long Beach Integrated Medical Intervention Response (IMR) Pilot Program was launched in January 2021. The goal of the Long Beach IMR is to ensure a safe environment for the public; safety for the first responders; and a system for providing safe, timely and appropriate medical care to individuals in crisis. Through the IMR, first responders are equipped to quickly recognize and safely treat ExD patients.
The IMR begins with the dispatchers at the Long Beach Department of Disaster Preparedness and Emergency Communications (DPEC), which is a combined public safety dispatch center that oversees both police and fire resources. DPEC dispatchers are trained in recognizing the signs and symptoms of excited delirium. Once ExD is identified, a dual response, involving police and fire, is dispatched to the scene. While en route, the responding police and fire resources communicate directly with one another to develop a coordinated plan, a rallying point, how to approach the patient and a contingency plan.
The IMR focuses on efficient communication that leads to a coordinated approach. Traditionally, fire personnel were instructed to stage away from the incident. While this provided an increased level of safety to the firefighter/paramedics, it often delayed medical assessment and care for a potentially critically ill individual. With the IMR, staging is avoided, and the first responders approach the patient together. With police and fire approaching as a unified team, the delay to medical attention and the need for use of force or prolonged physical restraint are all minimized.
Excited delirium response training
Prior to the implementation of the IMR pilot, citywide training was provided to each department, which focused on their respective skill set and their role within the IMR. The goal of the IMR training was to hone and integrate the skill sets to recognize and manage ExD. The focus of the police department training was geared toward de-escalation and public safety. The focus of the fire department training was to recognize and treat any life-threatening conditions.
After individualized department-specific training, multidisciplinary training sessions were held involving 500 sworn police officers, 335 firefighters and 62 dispatchers. The training involved both didactics and live simulations. These sessions emphasized intra-agency communication and how to work collaboratively to address these high-stress, high-risk, dangerous situations. By having members of the various agencies train together and share their experiences, they better appreciated the specific skills that each member brings to the team.
In compliance with LA County EMS Agency’s treatment protocol for agitated delirium, Long Beach paramedics are authorized for the administration of midazolam 5 mg for a “severely agitated patient requiring restraint for a patient or provider safety.”  Paramedics may repeat this dose once after 5 minutes if symptoms persist.
The training emphasized the importance of paramedics assessing each situation and evaluating the patient prior to deciding if they meet the protocol’s criteria for pharmacologic management.
It is important to note, that although working as a team through the IMR, police are not authorized to provide direction or influence fire personnel’s decision to administer a sedating agent. Additionally, medications shall not be given to facilitate placing someone into custody. Any patient who receives medications and/or for whom there is concern that an emergent medical condition exists will then be rapidly transported to an emergency department by paramedics in an ambulance for definitive care.
A national model
The IMR ensures the safety of all involved parties and rapid treatment of an agitated individual. This pilot has been supported by the Los Angeles County Emergency Medical Services Agency and serves as a model in the county and potentially nationally. Through continued collaboration and coordinated training, implementation of an IMR, both in Long Beach and in other communities, will improve the response to excited delirium incidents and ultimately lead to better outcomes for ExD patients.
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About the authors
Andrew Pachon, MD, is an emergency medical services fellow with LAC+USC Medical Center in Los Angeles.
Tiffany M. Abramson, MD, is the medical director of the Long Beach (California) Fire Department.