INTRODUCTION AND EPIDEMIOLOGY
This chapter is designed to provide the emergency provider with a general approach to the psychiatric emergency patient, identify potential pitfalls, and provide strategies for successfully managing this difficult patient population.
Psychiatric and behavioral emergencies have become a staple in every ED around the world. The busy emergency provider must successfully navigate encounters with patients who can exhibit a wide range of psychosocial pathology including substance use disorders, anxiety and agitation, depression and suicidal ideation, psychoses, neurocognitive disorders, and personality disorders, all of which can present with medical, psychiatric, or a combination of complaints.
Globally, according to the World Health Organization, one in four people suffer from mental illness or neurologic disorders, with depression as the number one cause of disability worldwide.1 The National Institute of Mental Health in the United States estimates that 1 in 5 Americans suffers from a mental, behavioral, or emotional disorder and 1 in 25 suffer from a severe mental illness.2 The Centers for Disease Control and Prevention announced a 24% increase in the rate of suicide in the United States from 1999 to 2014.3
Psychiatric patients have a higher incidence of medical conditions4-6 and a greater risk of injury7 than those without mental health or behavioral disorders. Fifty to 90% have at least one chronic medical condition and have a shortened life expectancy by anywhere from 8 to 30 years.8 Sixty percent of this shortened life expectancy is estimated to be due to physical illness. Moreover, the National Alliance on Mental Health reports that 26% of homeless people in the United States who live in shelters have a serious mental illness, and 24% of state prisoners had a “recent history of a mental condition.”9 This is of particular concern in urban, busy EDs and has special relevance for high ED users, discussed below.
GOALS OF CLINICAL EVALUATION
Anywhere from 7% to 10% of patients admitted to psychiatric wards have an organic condition that should have been identified, with higher figures often cited for patients at the extremes of life.10,11 Examples of missed life-threatening organic pathology include meningitis; sepsis; delirium; toxicologic processes including acetaminophen toxicity; neuroleptic malignant syndrome; metabolic abnormalities including hepatic encephalopathy, myxedema coma, or DKA; and traumatic conditions including epidural or subdural hematomas.12,13 The distinction between functional and organic causes is crucial because organic issues may be reversible with prompt intervention and failure to identify such pathology can have devastating outcomes. The evaluative process for identifying primary or comorbid medical conditions is often referred to as medical clearance.
Little disagreement exists over the evaluation of patients with no known psychiatric history who present with altered mental status or new-onset psychosis. Such patients are presumed to have an underlying medical disorder or an “organic” cause until proven otherwise. Clinical evaluation is ...