Delirium

Delirium is characterized by acute onset over hours to days, fluctuating course often worse at night, inattention, disorganized thinking, and altered consciousness ranging from hyperalert agitation to hypoactive somnolence. Hypoactive delirium is more common but underrecognized. Mixed type alternates between subtypes.

Common precipitants include infections (urinary, pneumonia), medications (anticholinergics, benzodiazepines, opioids), metabolic disturbances (electrolyte abnormalities, hypoglycemia), hypoxia, urinary retention, fecal impaction, sleep deprivation, and surgery. Predisposing factors include dementia, advanced age, sensory impairment, multiple comorbidities, and polypharmacy.

Diagnosis uses Confusion Assessment Method (CAM) requiring acute change with fluctuation plus inattention plus either disorganized thinking or altered consciousness. Treatment addresses underlying cause urgently. Non-pharmacologic interventions are first-line: orientation aids, family presence, hydration, mobilization, sleep-wake regulation, hearing aids and glasses. Antipsychotics only for severe agitation endangering safety. Avoid benzodiazepines except for alcohol withdrawal.