Delirium in Hospital - Evaluation and Management

Key Points

• Delirium is acute and fluctuating, with inattention as a core feature.
• Hypoactive delirium is common and frequently missed because the patient is quiet rather than disruptive.
• Always establish the patient’s cognitive baseline and identify one or more precipitating causes.
• Multicomponent nonpharmacologic care is the foundation of treatment and prevention.
• Review medications and reduce anticholinergics, unnecessary sedatives, and other contributors.
• Antipsychotics are not routine delirium therapy; reserve them for severe distress or dangerous behavior after de-escalation fails.
• Avoid benzodiazepines except for specific indications such as sedative withdrawal or seizure.
• Delirium can coexist with dementia, psychiatric illness, or catatonia.

Algorithm

1. Confirm acute change and inattention and establish baseline cognition from collateral sources.
2. Check vital signs, oxygenation, glucose, pain, hydration, bladder and bowel status, and medication changes.
3. Use targeted laboratory, imaging, toxicologic, neurologic, or infectious testing based on the clinical syndrome.
4. Treat identified causes such as hypoxia, infection, retention, constipation, withdrawal, or metabolic disturbance.
5. Implement orientation, sensory aids, sleep protection, mobilization, hydration, and family engagement.
6. Use verbal de-escalation before medication or restraints for agitation.
7. If severe dangerous agitation persists, use the lowest effective short-term antipsychotic only after contraindications are considered.
8. Reassess cognition and function frequently and plan safe follow-up for persistent symptoms.

Clinical Synopsis & Reasoning

Delirium develops over hours to days and fluctuates during the day. Inattention is central, accompanied by altered awareness and another cognitive disturbance such as disorganized thinking, memory impairment, language change, or perceptual disturbance. Hyperactive patients are easy to recognize because they pull lines or become agitated, but hypoactive delirium with sleepiness, slowed responses, and reduced movement is common and often missed. Mixed delirium alternates between these states.

Establish baseline cognition from family, caregivers, prior notes, or facility staff. Tools such as the 4AT or Confusion Assessment Method can support recognition, but diagnosis remains clinical. Identify precipitating factors systematically: infection, hypoxia, dehydration, pain, urinary retention, constipation, medication toxicity, anticholinergic burden, sedatives, withdrawal, electrolyte disturbance, renal or hepatic failure, stroke, seizure, sleep deprivation, environmental change, and sensory impairment. Older age, dementia, severe illness, frailty, and polypharmacy increase vulnerability, meaning relatively minor stressors can trigger major cognitive change.

Testing should be guided by the presentation. Obtain glucose and vital signs in every acute altered state. CBC, metabolic testing, urinalysis, chest imaging, blood gas, drug levels, ECG, neuroimaging, EEG, or lumbar puncture are selected according to symptoms and examination. Avoid diagnosing a urinary tract infection solely from asymptomatic bacteriuria in an older adult with delirium. A new focal deficit, head trauma, seizure, severe headache, or anticoagulation may justify brain imaging. Delirium can coexist with dementia, depression, psychosis, or catatonia and should not be excluded because another psychiatric diagnosis is already known.

Treatment Strategy & Disposition

Treat the underlying cause while providing a delirium-friendly environment. Reorient frequently, use visible clocks and calendars, ensure glasses and hearing aids are available, mobilize early, maintain hydration and nutrition, control pain, avoid unnecessary urinary catheters and restraints, normalize sleep-wake cues, and reduce nighttime interruptions when possible. Review every medication and stop or reduce nonessential anticholinergic, sedative, and psychoactive agents that may contribute. Involve family or familiar caregivers when helpful.

Verbal de-escalation and environmental modification are preferred for agitation. Physical restraints can worsen fear, injury, and delirium and should be used only when immediate safety cannot otherwise be maintained, with frequent reassessment. Antipsychotics do not treat the underlying delirium or reliably shorten its duration. A short course of low-dose haloperidol or an atypical antipsychotic may be considered when the patient remains severely distressed or poses a danger after nonpharmacologic measures fail, taking QT interval, Parkinson disease, Lewy body dementia, swallowing, and other risks into account. Benzodiazepines usually worsen delirium and are avoided except for specific indications such as alcohol or benzodiazepine withdrawal, seizures, or selected catatonia.

Discharge requires resolution or clear improvement of the acute cause, a safe cognitive and functional plan, medication reconciliation, and communication with caregivers and outpatient clinicians. Delirium can persist after the trigger is treated and predicts future cognitive and functional decline, so persistent symptoms should not be dismissed.

Epidemiology / Risk Factors

• Delirium is common among hospitalized older adults, ICU patients, postoperative patients, and people with dementia.
• Risk increases with frailty, sensory impairment, polypharmacy, severe illness, and baseline cognitive impairment.
• Many cases have multiple simultaneous precipitants rather than one isolated cause.
• Hypoactive delirium is at least as clinically important as hyperactive delirium and may carry a poor prognosis.

Investigations

Common Triggers

Pharmacology

Prognosis / Complications

• Delirium is associated with longer hospitalization, falls, institutionalization, functional decline, cognitive decline, and mortality.
• Symptoms may persist for days or weeks after the precipitating illness improves.
• Prevention and early treatment of modifiable triggers reduce complications.
• A delirium episode can reveal previously unrecognized cognitive vulnerability and should prompt follow-up when impairment persists.

Patient Education / Counseling

• Explain to family that delirium is a medical brain dysfunction that fluctuates and is not the same as dementia.
• Bring hearing aids, glasses, familiar objects, and calm orientation cues when possible.
• Avoid arguing with frightening misperceptions; reassure and redirect instead.
• After discharge, report recurrent confusion, fever, breathing difficulty, medication errors, falls, or reduced intake promptly.
• Persistent cognitive change after the acute illness deserves outpatient reassessment rather than being assumed permanent.

Notes

The highest-yield delirium treatment is often ordinary bedside care performed consistently. A patient who cannot hear, has not slept, is dehydrated, is constipated, and receives multiple sedating medications may remain delirious even after antibiotics successfully treat pneumonia. Multicomponent care addresses these interacting drivers.

Antipsychotics can be useful for a narrow problem: severe agitation or distress that creates immediate risk after de-escalation fails. They should not be prescribed simply because the patient is confused. If medication is used, document the target behavior, use the lowest effective dose, and reassess the need frequently.

Delirium and dementia are not mutually exclusive. Dementia is a major predisposing factor, and delirium superimposed on dementia can be difficult to recognize without collateral history. A change from baseline over hours to days should be treated as delirium until a better explanation is established.

References

1. NICE Guideline CG103: Delirium, updated 2023 — Link
2. American Geriatrics Society Clinical Resources — Link
3. Society of Critical Care Medicine PADIS Guidelines — Link