Kaplan + Sadock's Synopsis of Psychiatry, 11e

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Chapter 21: Neurocognitive Disorders

Table 21.2-2 Delirium Incidence and Prevalence in Multiple Settings

Table 21.2-4 Precipitating Factors for Delirium

Drugs

Prevalence Range (%)

Incidence Range (%)

Sedative–hypnotics Narcotics Anticholinergic drugs

Population

General medical inpatients

10–30

3–16

Treatment with multiple drugs Alcohol or drug withdrawal Primary neurologic diseases Stroke, nondominant hemispheric Intracranial bleeding Meningitis or encephalitis Intercurrent illnesses Infections Iatrogenic complications Severe acute illness Hypoxia Shock Anemia Fever or hypothermia Dehydration Poor nutritional status Low serum albumin levels Metabolic derangements Surgery Orthopedic surgery Cardiac surgery Prolonged cardiopulmonary bypass Noncardiac surgery Environmental Admission to intensive care unit

Medical and surgical inpatients

5–15

10–55

General surgical inpatients

N/A

9–15

postoperatively

Critical care unit patients Cardiac surgery inpatients

16

16–83

16–34

7–34

Orthopedic surgery patients 33

18–50

Emergency department

7–10

N/A

Terminally ill cancer patients 23–28

83 33

Institutionalized elderly

44

N/A, not available.

Advanced age is a major risk factor for the development of delirium. Approximately 30 to 40 percent of hospitalized patients older than age 65 years have an episode of delir- ium, and another 10 to 15 percent of elderly persons exhibit

Table 21.2-3 Predisposing Factors for Delirium

Demographic characteristics Age 65 years and older Male sex Cognitive status Dementia Cognitive impairment History of delirium Depression Functional status Functional dependence Immobility History of falls Low level of activity Sensory impairment Hearing Visual Decreased oral intake

Use of physical restraints Use of bladder catheter Use of multiple procedures Pain Emotional stress Prolonged sleep depravation

(Adapted from Inouye SK: Delirium in older persons. N Engl J Med . 2106;354(11):1157.)

delirium on admission to the hospital. Of nursing home residents older than age 75 years, 60 percent have repeated episodes of delirium. Male gender is also an independent risk factor for delirium. Delirium is a poor prognostic sign. Rates of institutional- ization are increased threefold for patients 65 years and older who exhibit delirium while in the hospital. The 3-month mor- tality rate of patients who have an episode of delirium is esti- mated to be 23 to 33 percent. The 1-year mortality rate for patients who have an episode of delirium may be as high as 50 percent. Elderly patients who experience delirium while hospitalized have a 21 to 75 percent mortality rate during that hospitalization. After discharge, up to 15 percent of these per- sons die within a 1-month period, and 25 percent die within 6 months. Etiology The major causes of delirium are CNS disease (e.g., epilepsy), systemic disease (e.g., cardiac failure), and either intoxication or

Dehydration Malnutrition

Drugs Treatment with psychoactive drugs Treatment with drugs with anticholinergic properties Alcohol abuse Coexisting medical conditions Severe medical diseases Chronic renal or hepatic disease Stroke Neurological disease Metabolic derangements Infection with human immunodeficiency virus Fractures or trauma Terminal diseases

(Adapted from Inouye SK: Delirium in older persons. N Engl J Med . 2106;354(11):1157.)