delirium /dilir″ē·əm/ [L, delirare, to rave] , 1. a state of frenzied excitement or wild enthusiasm. 2. an acute organic mental disorder characterized by confusion, disorientation, restlessness, clouding of the consciousness, incoherence, fear, anxiety, excitement, and, often, illusions; hallucinations, usually of visual origin; and, at times, delusions. The condition is caused by disturbances in cerebral functions that may result from a wide range of metabolic disorders, including nutritional deficiencies and endocrine imbalances; postpartum or postoperative stress; ingestion of toxic substances, such as various gases, metals, or drugs, including alcohol; and other causes of physical and mental shock or exhaustion. The symptoms are usually of short duration and reversible with treatment of the underlying cause; in extreme cases, however, in which the toxic condition is exceedingly severe or prolonged, permanent brain damage may occur. Compare dementia. Kinds include acute delirium, chronic delirium, delirium tremens, exhaustion delirium, senile delirium, traumatic delirium. −delirious, adj. ▪ OBSERVATIONS: There is a rapid onset and acute change in mentation. Manifestations include fluctuating levels of consciousness; disorientation; impaired memory; inability to maintain or shift attention; irritability, agitation, restlessness, and hyperactivity; perceptual disturbance, hallucinations, and delusions; rambling and fragmented speech; and impaired sleep-wake cycle. There are typically lucid intervals with symptoms worsening at night. Duration of symptoms is limited. There are four diagnostic criteria for delirium: (1) disturbance of consciousness with reduced awareness and diminished abilities to focus and to maintain or shift attention; (2) a change in cognition, such as disorientation, memory loss, or language disturbance; (3) the development of the disturbance over a period of hours to days, with fluctuation during the day; and (4) evidence from clinical exam and/or lab findings that the disturbance is caused by physiological consequences of a medical condition. Delirium places medically ill individuals at greater risk for medical complications (pneumonia and decubitus) and is associated with functional decline and institutional placement. Delirium may lead to dementia. ▪ INTERVENTIONS: Intervention centers around removal or withdrawal from toxic agents (alcohol and barbiturates) and IV sedation with antianxiety and antipsychotic agents for agitation, seizure activity, and tremors. Adequate fluid and electrolyte balance is also crucial. ▪ PATIENT CARE CONSIDERATIONS: Care during an acute episode of delirium is aimed at support, reduction of confusion and agitated behavior, and prevention of injury. Interventions include seizure precautions, safety precautions (e.g., prevent wandering and climbing over bedrails), environmental control (adequate lighting, noise reduction, clear space, removal of hazards, avoidance of sensory extremes, and allowance for adequate sleep), reorientation procedures (e.g., clocks, calendars, familiar objects, use of glasses and hearing aids), consistency of caretakers, and family involvement. Restraints should be avoided. Tactics to prevent delirium are crucial in susceptible individuals (e.g., those with chronic or mental illness, altered sensory perception, or neurological disease; those with elevated ammonia, increased blood urea nitrogen, or hypoxia; those on CNS stimulants or depressants), and those in altered environments (e.g., ICU, isolation, incubators, and institutions). This is accomplished by assessing and removing noxious environmental stimuli while increasing meaningful stimuli. Reduction of risk factors (e.g., sleep deprivation, visual or hearing impediments, adverse medications, dehydration, and pain) and use of orienting features (e.g., clocks, calendars, windows, and familiar objects) are important, as is maintaining verbal and nonverbal contact, with judicious use of touch. Structuring and explaining routines and procedures and interpreting sights, sounds, and smells in the environment are also crucial in preventing delirium.
