delirium

Delirium is an acute, fluctuating disturbance of consciousness and attention, with cognitive changes, caused by an underlying medical condition, substance use or withdrawal, or multiple etiologies. It develops over hours to days and fluctuates within a day. It is distinct from dementia.

Patients typically show inattention and disorganized thinking with altered awareness. They may be disoriented to time or place, have perceptual disturbances, and exhibit sleep-wake cycle disruption. Presentations may be hyperactive, hypoactive, or mixed.

Causes are diverse and often multifactorial. Triggers include acute medical illness (infection, organ failure), metabolic disturbances, hypoxia, dehydration, and circulatory problems. Medications with anticholinergic effects, sedatives, opioids, polypharmacy, and withdrawal from alcohol or benzodiazepines contribute.

Diagnosis relies on clinical assessment. Tools such as the Confusion Assessment Method (CAM) or 4AT aid detection. Criteria require disturbance in attention plus a cognitive change, acute onset with fluctuating course, and evidence of an underlying cause.

Management emphasizes identifying and treating the underlying cause and providing supportive care. Avoid deliriogenic medications when possible; ensure hydration, nutrition, and pain control; manage infections. Nonpharmacologic interventions include reorientation, early mobilization, sleep optimization, and sensory support. Pharmacologic treatment is reserved for severe agitation, with antipsychotics used cautiously; benzodiazepines are generally avoided except for withdrawal.

Prognosis is guarded; delirium is linked to higher mortality, longer hospital stays, and greater risk of dementia or institutionalization. Prevention with multicomponent, nonpharmacologic strategies in high-risk patients improves outcomes.

Common in older hospitalized patients, especially after surgery.