Delirium

DELIRIUM

Delirium has been defined in many ways. Some use the term to refer to an acute, hyperactive, confusional state. Psychiatrists define it more broadly to describe clinical states characterized by a reduced level of consciousness, an inability by the affected individual to sustain or shift attention appropriately, disorganized thinking, disorientation to time, place, or person, and memory impairment. In addressing the affected individual, questions need to be repeated, the individual may perseverate in responses, and speech may be rambling or incoherent. Additional features include an altered sleep-wake cycle, sensory misperceptions, disturbances in the pace of psychological and motor activity, and varying mood states (e.g., apathy, euphoria). Sensory misperceptions—usually visual ones—may include illusions (e.g., specks on the floor are thought to be insects) or hallucinations (one "sees" a relative in the room when there is actually no one there). Delusions may be present (e.g., the person is convinced that medical staff are secret government agents). The individual may respond emotionally (e.g., with anxiety) and behaviorally (e.g., attack those viewed as threatening) to the context of the delusion. There may be elevated blood pressure, a rapid heartbeat, and sweating and dilated pupils. The onset of such a clinical state is relatively rapid (taking an hour to days), the symptoms fluctuate throughout the course of illness, and the duration is usually brief (about one week). It is important to note that the altered level of consciousness exists on a continuum. Hypervigilance can progress to confusion and drowsiness.

The factors that may cause delirium are numerous. They can include head trauma, infections (e.g., meningitis), metabolic disorders, liver and kidney disease, postsurgical states, and psychoactive substance intoxication and withdrawal. The common underlying functional disturbance in delirium is diffuse impairment of brain-cell metabolism and stability. These changes can frequently be seen on an electroencephalogram (EEG). Delirium can occur at any age but is more common in the very young and the very old. It is most often seen in hospital settings. The treatment of delirium consists of maintaining critical bodily functions (i.e., cardiac and respiratory functions and hydration), correcting the precipitating problem, and managing the psychological and behavioral symptoms.

(See also: Delirium Tremens ; Withdrawal: Alcohol )

BIBLIOGRAPHY

American Psychiatric Association. (1987). Diagnostic and statistical manual of mental disorders-3rd edition-revised. Washington, DC: Author.

Horvath, T. B., et al. (1989). Organic mental syndromes & disorders. In H. I. Kaplan & B. J. Sadock (Eds.), Comprehensive textbook of psychiatry, 5th ed., vol. 1. Baltimore: Williams & Wilkins.

Lishman, W. A. (1987). Organic psychiatry, 2nd ed. London: Blackwell.

Plum, F., & Posner, J. B. (1980). The diagnosis of stupor and coma, 3rd ed. Philadelphia: Davis.

Myroslava Romach

Karen Parker