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Mental status is the clinical state of emotional and intellectual functioning of an individual. Patients presenting with altered mental status in the ED can include the diagnoses of delirium, dementia, and coma.


Clinical Features

Delirium is a transient disorder characterized by impaired attention, perception, thinking, memory, and cognition. Typically, delirium develops over a time course of days. Sleep–wake cycles may be disrupted, with patients exhibiting increased somnolence during the day and agitation characteristic of sundowning at night. Levels of alertness may be reduced, and activity levels may fluctuate rapidly. Different caregivers witnessing completely different patient behaviors within a brief time span may complicate making the diagnosis. Tremor, asterixis, tachycardia, sweating, hypertension, emotional outbursts, and hallucinations may be present. Features of delirium, dementia, and psychiatric disorders are listed in Table 142-1.

Table 142-1

Features of Delirium, Dementia, and Psychiatric Disorder

Diagnosis and Differential

The acute onset of attention deficits and cognitive abnormalities fluctuating throughout the day and worsening at night is characteristic of delirium. A detailed medication history should be obtained, as well as a mental status evaluation. ED evaluation is directed at identifying an underlying process contributing to the development of delirium such as infection (Table 142-2). Ancillary tests may include basic metabolic panel, hepatic studies, ammonia level, urinalysis, complete blood count, and chest radiograph. Cranial CT should be performed if a mass lesion is suspected, and clinicians may consider doing a lumbar puncture if meningitis or subarachnoid hemorrhage is suspected and an alternative diagnosis is not established.

Table 142-2

Important Medical Causes of Delirium

Emergency Department Care and Disposition

  1. Direct treatment at the underlying medical illness that is causing delirium. Environmental manipulation such as adequate lighting and emotional ...

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