Understanding Unspecified Delirium: Types, Symptoms, and Treatment
Acute Care • Geriatrics • Psychiatry
Understanding Unspecified Delirium: Types, Symptoms, and Treatment
“Unspecified delirium” is used when a patient meets criteria for delirium but an immediate, single underlying cause cannot be determined at presentation. This guide focuses on recognising the syndrome, prioritising safety, conducting pragmatic investigations, and delivering early management while causes are sought.
Definition & when to use this label
Unspecified delirium applies when the clinical picture fulfils delirium criteria (acute onset, fluctuating course, disturbed attention and cognition) but laboratory, imaging or history does not immediately reveal a clear cause. It is a working diagnosis prompting urgent stabilisation and targeted investigation rather than a final label.
Common clinical presentations
- Hyperactive delirium — agitation, hallucinations, restlessness.
- Hypoactive delirium — drowsiness, withdrawal, reduced responsiveness.
- Mixed presentation — fluctuates between hypo- and hyperactivity.
- Often accompanied by autonomic signs (tachycardia, hypertension), sleep–wake disruption and perceptual disturbances.
Why causes may be unclear initially
- Patient unable to give history (acutely confused) and no reliable collateral available.
- Polymorbidity and polypharmacy—multiple potential contributors (medications, infections, metabolic derangements).
- Novel or less detectable agents (novel psychoactive substances) or subacute processes (immune, metabolic) requiring specialist tests.
Assessment — immediate priorities (ABC + DELIRIUM)
- Airway, Breathing, Circulation: stabilise as required; oxygen and resuscitation where indicated.
- DELIRIUM mnemonic for targeted assessment:
- D — Drugs & toxins (prescribed, OTC, recreational)
- E — Electrolytes, endocrine, environmental causes
- L — Liver, kidney, metabolic derangements
- I — Infection (urine, chest, sepsis)
- R — Respiratory failure / hypoxia
- I — Intracranial events (stroke, haemorrhage, tumour)
- U — Urinary retention / constipation (common precipitants)
- M — Metabolic (glucose, thyroid), and miscellaneous (e.g., pain)
- Rapid bedside tools: 4AT or CAM for formal documentation of delirium.
- Assess capacity and document decisions; involve substitute decision-makers if required.
Investigations — a pragmatic panel
- Immediate: capillary glucose, oxygen saturation, ECG, temperature.
- Blood tests: CBC, electrolytes, renal & liver function, CRP, blood cultures if febrile, blood glucose, calcium, magnesium, phosphate.
- Other: urine analysis & culture, chest x‑ray, urine drug screen where indicated, pregnancy test in females of childbearing age.
- Neuroimaging (CT/MRI) if focal neurology, head injury, persistent or rapidly progressive decline.
- Consider EEG if seizures or non-convulsive status epilepticus suspected.
Management framework — stabilise, search, and support
When the cause is not immediately clear, act to stabilise the patient, perform syndrome-based treatments, and provide environment and supportive measures while investigations proceed.
- Stabilise: treat hypoxia, hypoglycaemia, and haemodynamic instability promptly.
- Search: use DELIRIUM mnemonic to guide investigations; liaise with specialists (infectious disease, neurology, toxicology) early if uncertain.
- Support: non-pharmacological measures—reorientation, ensure glasses/hearing aids, sleep hygiene, mobilisation, family presence.
Pharmacological strategies — cautious and targeted
- Avoid routine antipsychotic use for all delirium; reserve for severe agitation or psychosis risking harm. Use lowest effective dose (e.g., haloperidol low-dose or quetiapine) and monitor ECG.
- Avoid benzodiazepines except for alcohol/benzodiazepine withdrawal or when used for sedation in ICU under specialist guidance.
- Treat pain, constipation, urinary retention and sleep disruption—address reversible contributors to agitation.
Monitoring & disposition
- Determine appropriate level of care: observation, ward or ICU depending on severity, airway risk, haemodynamic stability and need for organ support.
- Frequent vital signs and mental state checks; chart fluctuations to help identify patterns and potential causes.
- Engage family/caregivers for collateral history and involve multidisciplinary team (pharmacy, geriatrics, psychiatry, neurology) early.
Red flags — escalate immediately
- New focal neurological signs, sudden unilateral weakness — urgent neuroimaging and stroke pathway activation.
- Persistent decreased consciousness or respiratory compromise — airway management and critical care escalation.
- Suspected non-convulsive seizures — obtain EEG and treat accordingly.
- Severe sepsis, neutropenia or rapidly progressive deterioration — urgent infectious disease/critical care input.
Case vignette
Patient: M., 78, admitted from nursing home with acute confusion and hypoactivity; no fever and limited history. Initial actions: ABC stable, 4AT positive for delirium, oxygen and glucose normal. Pragmatic investigations sent (CBC, electrolytes, CRP, urine culture, chest x‑ray, ECG). Non-pharmacological measures started with family reorientation. Labs revealed UTI—antibiotics started and mental state improved over 48 hours.
தமிழில் — சுருக்கம்
ஏதேனும்(one) காரணம் உடனடியில் தெரியாமல் இருப்பினும், டெலீரியம் உருவாகும்போது முதலில் நோயாளியின் பாதுகாப்பை உறுதி செய்து, அடிப்படை பரிசோதனைகள் மற்றும் சுற்றுச்சூழல் ஆதரவு வழங்க வேண்டும். காரணம் கண்டெடுக்கப்படும் வரை மருந்துகளை முறையாக பயன்படுத்த வேண்டாம்.
Key takeaways
- Unspecified delirium is a working diagnosis—prioritise stabilisation and a systematic search for causes.
- Non-pharmacological measures (reorientation, sleep hygiene, correction of sensory deficits) are first-line and effective.
- Use a pragmatic investigation bundle (DELIRIUM mnemonic) and escalate for red flags promptly.
- Pharmacotherapy should be cautious, targeted and short-term when used for severe agitation or psychosis.