Patients with delirium, dementia, and those with both delirium and dementia can be the most challenging patients in the emergency department (ED). Integration of psychiatric emergency services into the ED can help with cognitive assessment and management. Patients can also have delirium superimposed on dementia, making diagnosis and management more challenging. Although delirium can occur in patients across the lifespan, most studies have focused on older adults, as does this chapter. The most popular instruments for efficient screening of patients have been the Mini-Mental State Examination (MMSE), Confusion Assessment Method (CAM), CAM-ICU, Six-Item Screener (SIS), and the Mini-Cog. Treatment strategies for managing delirium are divided into non-pharmacologic and pharmacologic interventions and can definitely be implemented in the ED. Alzheimer's disease is the most common form of dementia, accounting for 50-80% of cases. The neuropsychiatric sequelae of dementia can make the diagnosis of a presenting patient more challenging.

Excited delirium syndrome (ExDS) is a specific type of extreme agitation. As patients with ExDS are often transported to an emergency department (ED), they are also cared for by emergency medicine clinicians. Currently, the majority of reported cases of ExDS are associated with stimulant drug use, such as cocaine or methamphetamine, although cases of ExDS still occur in psychiatric patients who are untreated or have abruptly discontinued their medication. This chapter reviews the existing literature on evaluation and treatment considerations for ExDS. Expert consensus guidelines recognize three classes of medications for initial calming of agitated patients: benzodiazepines, first-generation antipsychotics (FGA), and second-generation antipsychotics (SGA). Attention to airway maintenance, breathing adequacy, and volume resuscitation, along with rapid treatment of hypoglycemia, hyperthermia, and metabolic acidosis may be life saving. ExDS is a medical emergency, and cooperative protocols are needed between law enforcement, EMS, and local emergency departments to best manage these patients.