delirium
Pronunciation: deh-LEER-ee-um
An acute neuropsychiatric syndrome characterised by disturbances in attention, awareness, and cognition that develop over a short period and tend to fluctuate throughout the day; common and often underdiagnosed in hospitalised older adults.
Full Definition
Delirium is a clinically defined acute confusional state that arises secondary to an underlying medical condition, substance intoxication or withdrawal, medication effect, or a combination of these factors. In geriatric rehabilitation settings, delirium is a significant barrier to participation in therapy and is associated with increased morbidity and prolonged hospital stay. It is classified as hyperactive, hypoactive, or mixed subtype; the hypoactive form is frequently missed in documentation. Editors must not conflate delirium with dementia: delirium is acute and typically reversible, whereas dementia is chronic and progressive. The DSM-5 provides the current diagnostic framework.
Usage
Usage note: Always distinguish delirium from dementia in editorial review; the two terms are frequently and erroneously conflated in lay summaries and patient letters. Subtype (hyperactive/hypoactive/mixed) should be specified where documented.
In Context
- "Hypoactive delirium was suspected when the patient became uncharacteristically withdrawn and inattentive during the morning therapy session." — Physiotherapy progress note
- "The medical registrar's note distinguished the patient's delirium—of likely urinary tract infection aetiology—from his background vascular dementia." — Inpatient medical note