Delirium is an acute disturbance in cognition and attention with a fluctuating course as a result of a physiological disturbance (1,2).
|Disturbance in attention and awareness.|
The disturbance develops over a short period of time (usually hours to days), is a change from baseline, and tends to fluctuate during the day.
An additional disturbance in cognition (memory deficit, disorientation, language, visuospatial ability, or perception).
The disturbances are not better explained by another neurocognitive disorder and do not occur in the context of a severely reduced level of arousal, such as coma.
There is evidence from the history, physical examination, or laboratory findings that the disturbance is caused by a medical condition, substance intoxication or withdrawal, or medication side effect.
Additional features that may accompany delirium and confusion include the following:Psychomotor behavioral disturbances such as hypoactivity, hyperactivity with increased sympathetic activity, and impairment in sleep duration and structure.
Variable emotional disturbances, including fear, depression, euphoria, or perplexity.
- Delirium can result in problematic behaviours that endanger the patient, staff and others around them.
- If a patient is endangering their safety or the safety of those around them it should be a HIGH PRIORITY.
- Emergency requiring immediate attention.
Other problematic behaviors:
- High priority – attend as soon as possible.
- If new or rapidly progressing need to rule out other serious organic causes.
- Attend as soon as possible.
Table 1: Predisposing factors in Delirium (2,3,4)
|• Increasing age (>70 years)||• Cognitive impairment|
|• Depression||• Vision or hearing impairment|
|• Previous intracranial events||• Renal impairment|
|• ETOH dependence||• Malnutrition|
|• Thyroid dysfunction||• Previous history of delirium|
Precipitating factors in Delirium (2,3,4):
- Stroke, seizure, mass, encephalitis
- Organ dysfunction:
• cardiac via hypoxia
• respiratory via hypercapnia
• renal via uraemia
• liver via ammonia
- Drugs (including withdrawal) – opioids, benzos, anticholinergics
- Other causes:
- Urinary retention,
- recent Surgery
- Environmental change
Clinical features #
- Alteration in cognition and attention
- Fluctuating course
- Increase or decrease in psychomotor activity
- Altered sleep-wake cycle
Classification (2, 5):
- Hypoactive: decreased psychomotor activity, sometimes appearing sedated.
- Hyperactive: increased psychomotor activity, often with hallucinations and delusions.
- Mixed: symptoms of both hypoactive and hyperactive delirium.
- 4AT (6)
- CAM (2, 6)
Online versions of the 4AT screening test can be found on MDCalc:
Copies of the screening test can be accessed via this link: https://www2.health.vic.gov.au/hospitals-and-health-services/patient-care/older-people/cognition/delirium/delirium-identifying
Differential diagnosis (2):
- Dementia – BPSD
- Primary psychiatric illness
- Focal neurological syndrome e.g. hemorrhage, tumour
- Non-convulsive status epilepticus
Initial investigations (4)
|Bedside:||Urinalysis and Urine MCS (if urinalysis abnormal)ECGGlucose|
|Bloods:||Full blood examination Urea and electrolytes Calcium, Magnesium, Phosphate Liver function tests Cardiac enzymes|
Further investigations (4)
|Specific Cultures (e.g. sputum, blood, LP)||If evidence of infective focus or concern for sepsis.|
|ABG||If SOB, cough and/or abnormal chest radiograph|
|CT Brain||If history of falls, patient on anticoagulant therapy or focal neurology|
|EEG||May assist in determining aetiology if other investigations don’t find cause. E.g. non-convulsive status epilepticus|
|Thyroid function test||If history or examination findings suggest thyroid pathology|
|B12 and Folate||If potential for deficiency|
Non-Pharmacological Management #
Treat underlying cause:
- Correct electrolyte abnormalities if present
- Treat an underlying infection if present
- Ensure adequate hydration
- Treat urinary retention or constipation if present
- Medication review – withhold drugs suspected to contribute to delirium
- Provide appropriate analgesia (3,4)
Provide supportive care:
- Reduce noise (e.g. single room)
- Orientating stimuli (e.g. appropriate lighting, clocks, calendars, familiar items)
- Hearing or visual aids if required
- Promote mobility and assistance with ADLs
- Encourage regular and normal sleep-wake cycle
- Reassurance and continuity of care (e.g. consistency of staff members, one-to-one nursing, opportunity for family member/carer to be with patient) (3,4)
- Falls prevention (e.g. low bed against the wall with crash mat, no physical restraints)
- Pressure care (e.g. routine mobilisation with physical assistance)
- Swallow assessment (referral to speech pathology)
- Behavioral management (e.g. behavioural charts) (3,4)
Educate the patient and their family
Pharmacological Management #
Drugs are NOT required to manage most patients with delirium (7)
Antipsychotics carry significant risk of adverse effects and serious complications including death, and therefore must be prescribed with caution. Older frail patients are at higher risk of adverse outcomes.
Only use antipsychotics in delirium if:
- It is causing significant distress to the patient
- They are at risk of harming themselves or others
- It is preventing essential investigations or treatment
- Non-pharmacological methods are not managing symptoms sufficiently (5)
Do NOT prescribe antipsychotics to manage the following behaviours:
- Calling out/vocalisations
- Non-distressing delusions
The prescribing doctor must document the medical indication for prescribing antipsychotics and include their assessment of risk to the patient and others posed by the symptoms that they are intended to treat. The next of kin should be notified of their use (in daylight hours).
Consider involving senior help before administering an antipsychotic.
A single dose of antipsychotic is usually adequate.
Avoid using benzodiazepines except for delirium caused by alcohol or benzodiazepine withdrawal, or seizures.
Hospital guidelines may defer from below; consider checking your hospital’s guidelines.
If they do not have Parkinson’s disease or dementia with Lewy bodies
|Haloperidol 0.5 mg PO/IM 1 mg may be required in younger patients) single doseORRisperidone 0.5 mg PO (1 mg may be required in younger patients) single doseOROlanzapine 1.25 to 2.5 mg PO/IM single dose (7,8)|
If Parkinsonism or Dementia with Lewy Bodies:
|Quetiapine 25 mg PO single dose (7)|
The onset of medication effect (even IM) is unlikely to be immediate – can be delayed by 30 to 60 minutes – do NOT give a second antipsychotic dose for at least 30 minutes (7).
- Inouye SK, Westendorp RG, Saczynski JS. Delirium in elderly people. The Lancet. 2014 Mar 8;383(9920):911-22. [Cited 2021 Aug 29]
- Francis J, Bryan Young G.Diagnosis of delirium and confusional states . In: Klein-Gitelman M, TePas E, editors.;UpToDate. [Internet]. Waltham (MA): UpToDate Inc; 2021. [updated 2019 May 22; cited 2021 Aug 29]. Available from: https://www.uptodate.com/contents/diagnosis-of-delirium-and-confusional-states?search=delirium&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1
- Francis J.Delirium and acute confusional states: Prevention, treatment, and prognosis . In: Klein-Gitelman M, TePas E, editors.;UpToDate. [Internet]. Waltham (MA): UpToDate Inc; 2021. [updated 2019 May 22; cited 2021 Aug 29]. Available from: https://www.uptodate.com/contents/delirium-and-acute-confusional-states-prevention-treatment-and-prognosis?search=delirium&source=search_result&selectedTitle=2~150&usage_type=default&display_rank=2
- Commonwealth of Australia, Department of Health and Ageing. Delirium Care Pathways [Internet] Canberra, ACT: Commonwealth of Australia; 2011 [updated 2011 September; cited 2021 Aug 29].Available from: https://www1.health.gov.au/internet/main/publishing.nsf/Content/FA0452A24AED6A91CA257BF0001C976C/$File/D0537(1009)%20Delirium_combined%20SCREEN.pdf
- de Rooij SE, Schuurmans MJ, Mast RV, Levi M. Clinical subtypes of delirium and their relevance for daily clinical practice: a systematic review. International Journal of Geriatric Psychiatry: A journal of the psychiatry of late life and allied sciences. 2005 Jul;20(7):609-15. [Cited 2021 Aug 31]
- Victoria State Government, Department of Health. Identifying Delirium – Screening and Assessment [Internet] Melbourne VIC: State of Victoria; 2020 [cited 2021 Aug 31]. Available from: https://www2.health.vic.gov.au/hospitals-and-health-services/patient-care/older-people/cognition/delirium/delirium-identifying
- eTG complete [Internet]. Melbourne (Vic): Therapeutic Guidelines Ltd; 2021.Delirium [updated 2021 March; cited 2021 Aug 29]. Available from: https://tgldcdp.tg.org.au/viewTopic?topicfile=delirium&guidelineName=Psychotropic&topicNavigation=navigateTopic
- Australian medicines handbook online [Internet]. Adelaide (S. Australia): Australian Medicines Handbook Pty Ltd; 2000. Olanzapine; [updated 2021 Jul; cited 2021 Sept 20]. Available from: https://amhonline-amh-net-au.eu1.proxy.openathens.net/chapters/psychotropic-drugs/antipsychotics/olanzapine#olanzapine-indication
Reviewing Consultant/Senior Registrar
Dr Luke Foley
A/Prof. Louisa Ng