Delirium Health Article

Definition

Delirium is a transient, abrupt, usually reversible syndrome characterized by a disturbance that impairs consciousness, cognition (ability to think), and perception.

Description

The word delirium is derived from the Latin delirare which literally translates "to go out of the furrow." Delirium is typically an acute change in thinking with a disturbance in consciousness. Delirium is not a disease, but a syndrome that can occur as a result of many different underlying conditions. Typically, there is a broad range of accompanying symptoms. Delirium is also called acute confusional state. Delirium is a medical emergency and affects 10–30% of hospitalized patients with medical illness. It is a widespread condition that affects more than 50% of persons in certain high-risk population. Often the condition can be reversed, but delirium is associated with increased morbidity and mortality rates.

Demographics

Patients who develop delirium during hospitalization have a mortality rate of 22–76% and a high death rate months after discharge. Approximately 80% of patients develop delirium near death, and 40% of patients in the intensive care units have symptoms of delirium. The prevalence of postoperative delirium following general surgery is 5–10%, and 42% following orthopedic surgery. Delirium is very common in nursing homes. The exact incidence of delirium in emergency departments is unknown. Delirium is present in approximately 20% of medical patients at the time of hospital admission. The prevalence in hospitalized patients is approximately 10% on a general medical service, 8–12% on a psychiatric service, 35–80% on a geriatric unit, and 40% on a neurologic service. In the elderly and postoperative patients, delirium may result in long-term disability, increased complications, and prolonged hospital stay. Geriatric patients have the highest risk for developing delirium. The incidence is higher among young children, females, and Caucasians. Medications are the most common cause of delirium in the elderly, which accounts for 22–39% of cases. Medications are the most common reversible causes of delirium. Approximately 25% of hospitalized patients with cancer and 30–40% of patients with HIV (AIDS) infection develop delirium during hospitalizations.