Delirium

Delirium is never benign and never "expected." Every episode of delirium has an underlying medical cause that must be identified and treated. The delirium itself is associated with increased mortality, prolonged hospitalization, functional decline, and accelerated cognitive deterioration. Treating delirium as a nuisance rather than an emergency is a clinical error with measurable consequences.

Hypoactive delirium is the most common subtype and the most frequently missed. The patient is quiet, withdrawn, not agitated, and not causing problems for staff. It gets mislabeled as depression, fatigue, sedation, or "baseline dementia." It carries a worse prognosis than hyperactive delirium precisely because it is detected later and the underlying cause has more time to do damage. If an elderly inpatient becomes acutely quiet and withdrawn, test their attention. Do not assume depression.

In terminally ill patients, new-onset delirium is often a sign of impending death in the final days to weeks of life. While potentially reversible causes should still be considered based on goals of care, the development of delirium in this context frequently signals irreversible multi-organ decline. The clinical conversation shifts from cure to comfort, and family preparation becomes a central priority.

Dementia is the single greatest risk factor for delirium. When a patient with known cognitive impairment acutely worsens, do not attribute the change to their dementia. Acute changes in cognition, behavior, or function in a patient with dementia should be treated as delirium until proven otherwise. The delirium is the treatable emergency.