Hyperactive Delirium

Hyperactive delirium is an acute disturbance of attention and awareness with restlessness, agitation, hallucinations and sometimes aggression. It is the most conspicuous but not the most common subtype of delirium.

It occurs on medical and surgical wards, intensive care, and after alcohol or sedative withdrawal. Older patients with dementia are at highest risk.

Pathophysiology. Excess dopaminergic and noradrenergic activity with cholinergic deficiency, neuroinflammation and stress responses disrupt attention networks. Typical precipitants are infection, drugs (anticholinergics, benzodiazepines, opioids, steroids), withdrawal, pain, retention and metabolic disturbance.

Agitation, wandering, pulling at lines and catheters, shouting, hallucinations, paranoid ideas, insomnia with night time worsening, and fluctuation over hours. Risks include falls, injury, exhaustion and harm to staff.

Red flags.

• Fever, rigidity and autonomic instability (serotonin syndrome, neuroleptic malignant syndrome, sepsis).
• Alcohol or benzodiazepine withdrawal with tremor and sweating.
• New focal deficit or head injury.

Use a validated screening tool and examine for a physical cause: observations, glucose, oxygen saturation, temperature, hydration, bladder and bowel, pain, drug and alcohol history, and focused examination. Order full blood count, electrolytes, calcium, liver tests, C-reactive protein, urinalysis if symptomatic, ECG and chest radiograph; image the brain when indicated.

Differential diagnosis.

• Alcohol and sedative withdrawal.
• Acute psychosis, mania and agitation of dementia.
• Anticholinergic toxicity, akathisia and thyrotoxicosis.
• Seizures and postictal states.

Treat the cause. Use non-drug measures first: a calm environment, consistent staff, glasses and hearing aids, clocks, family, and avoidance of restraint. Use drugs only when the patient is distressed or a danger.

Give haloperidol 0.25 to 0.5 mg orally or intramuscularly, repeated after 2 hours if needed, to a maximum of 2 mg in 24 hours in frail patients, with an ECG for QT interval. Avoid haloperidol in Parkinson disease and Lewy body dementia; use quetiapine 12.5 to 25 mg instead.

Benzodiazepines (lorazepam 0.5 to 1 mg) are for withdrawal states only. Stop drugs once the agitation settles.

Monitoring. Sedation, vital signs, QT interval and review of ongoing need.