Delirium
Delirium is an acute, fluctuating disturbance of attention and awareness caused by an underlying medical, toxic, or metabolic insult. Diagnosis rests on the Confusion Assessment Method; management is identification and treatment of the precipitating cause plus withdrawal of deliriogenic drugs, reserving antipsychotics for safety only.
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What this article covers
- Overview
Definition: delirium is an acute alteration of brain function centered on impaired attention and awareness, developing over hours to days and fluctuating in severity, arising from dysfunction of the…
- Epidemiology
Setting-dependent frequency: prevalence varies by population and is highest among postsurgical and older intensive care unit patients.
- Risk factors
Baseline cognitive impairment: dementia or mild cognitive impairment is the strongest predisposing factor.
- Pathophysiology
Arousal system dysfunction: the core disturbance is in the ascending reticular activating system, producing the hallmark fluctuations in mentation and altered circadian rhythm.
- Clinical features
Core feature - impaired attention: poorly sustained and easily distractible attention is the hallmark finding, best elicited by asking the patient to perform a simple sustained task (such as reciting the months backward).
- Differential diagnosis
Dementia: chronic, gradually progressive cognitive decline without the acute onset or fluctuating course of delirium; attention is relatively preserved until late-stage disease, unlike delirium where…
- Diagnosis
Diagnostic tool: the Confusion Assessment Method (CAM) has good sensitivity for diagnosing delirium and establishes the diagnosis at the bedside by confirming acute onset with fluctuating course…
- Management
First step - identify and treat the underlying cause: this is the primary treatment of delirium; correct the metabolic derangement, treat the infection, and address hypoxia or organ dysfunction as identified on workup.
- Complications
Prolonged hospitalization: longer lengths of stay independent of the precipitating illness.
- Prognosis
Reversibility: most delirium resolves once the underlying cause is identified and treated, but resolution can lag behind correction of the precipitant by days, and some cognitive symptoms may persist…
- Prevention
Multicomponent nonpharmacologic protocols: in hospitalized patients, providing assistive visual and hearing devices, adequately controlling pain, limiting psychoactive medications, providing frequent…
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