The geriatric patient with delirium is one of the most common psychiatric consultation requests in medical hospitals — and one most often handled poorly when "psychiatry" is reflexively called for what is fundamentally a medical condition. Delirium is medical until proven otherwise. The psychiatric symptoms are downstream; finding and treating the cause is the work.
Delirium features: acute onset (hours to days, not weeks). Fluctuating course (the patient is more clear at some times, more confused at others, often with worsening in the evening — "sundowning"). Inattention prominent (can't focus, can't follow simple commands consistently). Altered consciousness (variously sleepy, hyperalert, or alternating). Disorganized thinking. Sometimes visual hallucinations or perceptual disturbances. Sometimes agitation (hyperactive delirium); sometimes profound quietness (hypoactive delirium — often missed because the patient is "easy").
Common causes in elderly hospitalized patients: infection (UTI is the classic; pneumonia common). Hypoxia. Electrolyte disturbances. Glucose extremes. Medication changes — new psychotropics, anticholinergics, opioids, benzodiazepines. Postoperative state (anesthesia, pain, sleep disruption). Substance intoxication or withdrawal. Stroke or other acute neurologic events. Often multifactorial.
Workup: vital signs trend, full physical exam, oxygen saturation, electrolytes, glucose, CBC with differential, urinalysis, chest X-ray if indicated, medication review with attention to recent additions. Brain imaging if focal findings or unexplained. ABG if respiratory concerns. The workup is broad initially because the cause may be one of several.
Management: treat the cause. Non-pharmacologic interventions first for agitation — reorient, family presence, day-night cues, mobility, hydration, pain control. Avoid restraints when possible. Symptomatic medication only for severe agitation with safety risk; low-dose haloperidol or atypical preferred over benzodiazepines (which often worsen delirium, except in alcohol withdrawal). Avoid anticholinergics, which worsen the cognitive state.
Reassessment often. Delirium resolves with treatment of cause; the trajectory should improve over days. Persistent or worsening delirium prompts re-investigation. Document the cause when identified and the resolution as it occurs.