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The neurocognitive disorders (NCDs) comprise a group of conditions defined by decline from a previous level of cognitive functioning. The six cognitive domains that may be affected include complex attention, executive function, learning and memory, language, perceptual-motor skills, and social cognition (interaction). By definition, cause(s) for the deficits may be ascertained from findings on history, physical exam, and diagnostic testing. The DSM-5 divides the NCDs into three main categories: delirium, mild NCDs, and major NCDs (dementias).
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Delirium is a medical emergency.
May be the only early manifestation of serious illness.
Potentially reversible.
Can advance to coma, seizures, or death.
Associated with high mortality. Up to 40% of individuals die within 1 year of diagnosis.
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WARDS TIP
Terms commonly used for delirium include toxic or metabolic encephalopathy, acute organic brain syndrome, acute confusional state, acute toxic psychosis, and ICU psychosis.
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Up to one-half of hospitalized elderly patients develop delirium.
As many as 90% of patients with a preexisting NCD (dementia) will experience a superimposed delirium when admitted to the hospital.
Delirium often goes unrecognized (65–88% of the time).
Delirium is associated with an increased risk for later development of major NCD.
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WARDS TIP
Consider delirium as acute brain failure—a medical emergency like other acute organ failures.
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Advanced age.
Preexisting cognitive impairment or depression.
Prior history of delirium.
Severe or terminal illness.
Multiple medical comorbidities.
Hearing or vision impairment.
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WARDS QUESTION
Q: What is the “ICU triad?”
A: Pain, Agitation, and Delirium.
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Precipitating Factors
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Polypharmacy, including the use of psychotropic medications (especially benzodiazepines and anticholinergic drugs).
Alcohol use or withdrawal.
Infection.
Pain.
Dehydration.
Malnutrition.
Impaired mobility.
Sleep deprivation.
Organ failure.
Mechanical ventilation.
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WARDS TIP
Delirium is commonly experienced by patients in the ICU and postoperative recovery.
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WARDS TIP
Common causes of medication-induced delirium:
Anticholinergics
Benzodiazepines
Nonbenzodiazepine hypnotics (“Z-drugs”)
Opioids (especially meperidine)
Corticosteroids
Tricyclic antidepressants
H2 blockers
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