Delirium - Clinical Guideline for the Diagnosis and Management of Delirium in adults

Publication: 22/07/2016  
Next review: 08/04/2023  
Clinical Guideline
ID: 4699 
Approved By: Trust Clinical Guidelines Group 
Copyright© Leeds Teaching Hospitals NHS Trust 2020  


This Clinical Guideline is intended for use by healthcare professionals within Leeds unless otherwise stated.
For healthcare professionals in other trusts, please ensure that you consult relevant local and national guidance.

Clinical guideline for the diagnosis and management of delirium in adults


Delirium is a common and serious clinical syndrome characterised by a disturbance of attention which is acute in onset and has a fluctuating course. There is an additional disturbance of cognition, such as memory, orientation or perception. The condition usually has reversible causes or precipitants which can be identified and treated, and is not better explained by an existing condition. 

It can be subdivided into two major subtypes; hyperactive and hypoactive delirium. It is important to note that hypoactive delirium is the commonest type, is less well recognised and has a poorer prognosis. Their characteristics are described below.

  • Hyperactive delirium: increased motor activity, agitation, hallucinations, inappropriate behaviour.
  • Hypoactive delirium: reduced motor activity and lethargy. May appear withdrawn, not eating as much, not moving as much, not talking as much.

The prevalence of delirium in people on medical wards in hospital is about 20% to 30%. Between 10% and 50% of people having surgery develop delirium. Older people, those with a current hip fracture or a serious illness and those with dementia are at higher risk of developing delirium. The prevalence of delirium in patients with dementia is 66%.

People who develop delirium:

  • are more likely to stay longer in hospital or in critical care
  • are more likely to have hospital-acquired complications, such as falls and pressure sores
  • are more likely to need to admission to long term care facilities
  • are more likely to have pre-existing dementia (which may or may not have been diagnosed)
  • are more likely to die

This guidance does not apply to delirium caused by alcohol or drug intoxication or withdrawal (where separate guidance is available). Nor does it apply to those receiving care in the last days of life or patients in critical care units

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Identifying Delirium

Think ‘Delirium’

Identify patients at risk of Delirium

Those at increased risk of delirium include:

  • 65 years or older
  • Cognitive impairment and/or dementia
  • Current hip fracture
  • Severe illness

Single question in delirium (SQiD)

‘Has this person been more confused lately?’
If the answer is yes, then 80% of these patients will have delirium. [Grade B]

This include patients who are not themselves in some way, for example:

  • Not waking as much as usual
  • Not eating or drinking as much as usual
  • Not walking as well as usual
  • Not talking as much as usual

Complete further assessment for delirium if SQiD is positive or other clinical concerns that the patient may have delirium

Complete a 4AT if SQiD is positive or other clinical concerns for delirium. [Grade B] It has a sensitivity of 86% and a specificity of 84% for diagnosis of delirium. The tool is in the appendix and available as a clinical document in PPM.

A negative 4AT does not completely rule out delirium so clinical assessment may be required if there are clinical concerns for delirium.

If the 4AT is positive or there are other clinical concerns for delirium, a clinical assessment should be performed for delirium.

Diagnosing Delirium
A collateral history from family or carers is essential and should be clearly documented.  You should ask:

  • Have they been more confused than normal? Unable to concentrate? Struggling to respond or drifting off in conversation?
  • Do they jump from topic to topic with rambling speech?
  • Have they been hearing things or seeing things that aren’t there?
  • Have they been restless or agitated?
  • Have they been walking less - “off legs”?
  • Have they been eating and drinking less?
  • Have they been sleeping more, or restless at night?
  • Have they been unco-operative or socially withdrawn?

The diagnosis of delirium can then be confirmed by a clinical assessment with reference to the DSM V criteria below. [Grade C]

DSM V criteria for delirium

  1. Disturbance in attention (reduced ability to direct, focus, sustain, and shift attention) and awareness (reduced orientation to environment).
  2. An acute change, that develops over a short period of time (usually hours to days), and tends to fluctuate
  3. An additional disturbance in cognition (memory deficit, disorientation, language, visuospatial ability, or perception)
  4. The disturbances are not better explained by another pre-existing, evolving or established neurocognitive disorder, and do not occur in the context of a severely reduced level of arousal, such as coma
  5. 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. There may be multiple causes

The diagnosis of delirium should be documented in the patient’s medical notes and communicated to nursing staff, the patient and their relative/next of kin.

Provide the joint LTHT and LYPT Delirium patient information leaflet to the patient and their carer available iProc system

Differential Diagnosis of delirium

The differential diagnosis of delirium includes:

  • Dementia
  • Depression
  • Non-convulsive epilepsy
  • Psychotic illness

If the diagnosis is unclear, assume delirium and treat reversible causes whilst seeking a second opinion.  Consider a referral to liaison psychiatry or neurology if a neurological condition is suspected (x67147).

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Investigate cause of delirium

The aim of clinical assessment is to identify precipitants of delirium

Clinical History

A history from the patient and collateral history from family/carers should aim to get a clear sense of recent events. A thorough medical review should be performed.  Any acute illness can precipitate delirium, and while infection is a common cause for delirium, it is not the only cause.  Multiple precipitating factors are often found.

In patients with pre-existing dementia and frailty, delirium may be precipitated by only a small change e.g. constipation or a new medication.
A surprising number of medications may have anticholinergic activity which can cause constipation, urinary retention, delirium and increase the risk of delirium. has more information of drugs at high risk of worsening confusion.  [Grade B]


A thorough physical examination should be carried out. Most acute illnesses can cause delirium. Pain is an under-recognised cause of delirium - use an assessment tool to identify nonverbal signs of pain. Dehydration is also common in patients with delirium and should be treated. Particular attention should be paid to the neurological examination, including GCS, cranial and peripheral nervous examination.

Clinical assessment for infection should be completed. Urinary retention is a commonly missed cause of delirium and should be considered when there are urinary symptoms (it is not uncommon for people to have urinary frequency and co-existent retention), agitation or distress, or a palpable bladder. Catheterisation may provide relief of distress when there is unrecognised symptomatic retention. However, catheters may in themselves may cause delirium, distress, or infection so the pros and cons of a catheter should be considered before insertion, and they should be removed as soon as possible. Constipation and anticholinergic medications can cause urinary retention and should be considered as a precipitant for this. [Grade C]


Basic blood tests:

    • FBC, U&E, CRP, LFT, Calcium
    • TFTs, Vitamin B12, Folate (if delirium present weeks or longer and not already done in this timeframe)
    • Capillary blood glucose
    • Consider arterial blood gas and lactate if indicated

Cultures are indicated where infection is suspected. Remember that older people may not have a systemic inflammatory response or specific symptoms. It should also be noted that older people may have a normal or low temperature in the presence of infection.

    • MSU if UTI is suspected - urine dipsticks are not accurate in older patients
    • Blood cultures
    • Stool cultures if diarrhoea
    • Sputum cultures if cough

ECG. This is useful as a baseline and, rarely because frail older people with cognitive impairment may be present with confusion or distress when having an acute coronary syndrome.

CXR – if clinical suspicion of conditions such as pneumonia or heart failure. Older people often don’t have clear signs on physical examination so consider if features of infection, tachypnoea or hypoxia

AXR - if clinical suspicion of perforation or obstruction.

A CT head scan should be considered in the following scenarios and the urgency dependent on the suspected diagnosis (see head injury and stroke guidelines)

  • New focal neurological signs
  • Reduced consciousness not explained by other causes
  • Delirium presenting after a fall
  • Delirium after a head injury particularly if on anticoagulation therapy

Specific drug levels should be considered in patients on drugs with a narrow therapeutic index for example digoxin and lithium.

If unusual features,
An opinion should be sought from a specialist with experience in managing delirium e.g. specialist in Elderly Medicine or specialist liaison psychiatrist for older people. A neurology referral may be appropriate where it is felt likely that there is an underlying neurological condition.

Seizure activity and encephalitis are uncommon but serious causes of delirium to consider. 

Subsequent investigations may include lumbar puncture, EEG, MRI, toxicology or cortisol depending on clinical concern (please seek specialist/senior advice before organising any of these tests). 

[Grade C]

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Treatment and Management of delirium

Medical Management

  1. Find and treat the underlying cause/causes.
  2. Minimise or avoid other precipitants that may contribute

[Grade A]

These principles apply to both those with delirium and those at risk of developing delirium

Some causes may have been identified in the clinical assessment above. In addition, use the PINCH ME approach to management documented below. This table can be printed and used in the patient notes.

Pinch Me Approach to managing delirium


Nursing team/MDT





  • Look for nonverbal signs of pain e.g. whimpering, groaning, crying, signs of discomfort or distress.
  • Use a formal tool to assess and treat pain


  • Look for nonverbal signs of pain and prescribe simple analgesia . Opiates may be required for more severe pain but use with care.



  • Send MSU if infection suspected (as part of a broader infection screen)


  • Assess clinically for infection and send appropriate blood tests e.g. CRP. Further tests as indicated.  Treat infection as per guidelines. Not all patients will have infection.



  • Ensure dentures in place and fitting.
  • Ensure nutritional screening completed and follow Oral Nutritional Care Plan including use of red trays and food charts.
  • Consider use of finger food menu.
  • Ask family to help with mealtimes.  


  • Review food charts and prescribe supplements as recommended. Consider dietician referral as per trust policy.



  • Complete stool chart. Contact doctor if constipated
  • Assess and encourage regular toileting
  • Do a bladder scan if signs of distress/discomfort, passing urine frequently, not passing urine or if otherwise indicated
  • Avoid catheter unless indicated and remove as soon as able

  • Prescribe laxatives as appropriate. Aim for regular bowel motions.
  • Consider PR +/- enema if impacted
  • Bladder scan and catheter if indicated (see main text of guideline)




  • Ensure drinks offered regularly and with each interaction.
  • Ensure drinks are within patients reach.
  • Monitor fluid balance.
  • Ensure mouth care is provided


  • Consider SC/IV fluids if dehydrated
  • Treat oral candida
  • Ensure food/fluid in reach and offer oral fluids with each interaction


Medications and Metabolic

  • Ask doctor or pharmacist to review medications


  • Review drugs  which may contribute to delirium (see trust guidelines for delirium) and reduce or stop these drugs where possible
  • Ensure oxygenation is adequate and prescribe oxygen in line with LTHT guidelines
  • Send U+Es/LFTs/calcium
  • Send B12/folate/TFTs if not done in last 3 months




  • Re-orientate e.g. “I am James, the nurse looking after you today. It is Monday morning and you are in LGI recovering from a hip operation”
  • Ask relative/friend to Complete This Is Me booklet and use to provide person centred care
  • Avoid ward moves
  • Consider noise levels, appropriate lighting, clock, calendar, familiar objects
  • Ensure hearing aids and glasses are used and working
  • Encourage family to visit
  • Provide delirium leaflet to family (LN003921)
  • Encourage mobility and identify if falls risk


  • Re-orientate
  • Ask relative or friend to Complete This Is Me booklet and use to provide person centred care
  • Explain diagnosis to family and provide with delirium leaflet
  • Consider checking for ear wax. Refer to audiology if required.
  • Encourage mobility



Detailed environmental considerations

Simple changes to the ward environment can help reduce delirium.

  • Introducing yourself gently and re-orientating e.g. Good Morning. It is Monday and I am James, the nurse looking after you in Leeds General Infirmary
  • Using the ‘This Is Me’ booklet to understand preferences, likes, dislikes and routines can be helpful
  • Allowing family to visit and help with re-orientation and mealtimes.
  • Provide family with the delirium leaflet (LN003921)
  • Promote sleep at night and wakefulness in the day
  • Ensure clocks clearly visible
  • Promote calm and consistent environment
  • Avoid ward moves, especially at night
  • Reduce level of noise and stimulation at night
  • Minimise need for observations at night
  • Ensure lighting mimics the time of day
  • Encourage mobility as much as possible



Patients should be regularly assessed to ensure delirium is resolving. This should include:

  • Observation by the MDT including overnight
  • Improvement/deterioration as reported by family/friends/carers - this can be very helpful in assessing progress
  • Regular assessment using the Single Question in Delirium “Has this person been more confused lately?”
  • Repeated cognitive testing e.g. AMTS or 4AT
  • An altered level of alertness should prompt a full re-assessment for the presence of delirium

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Distress and Agitation in delirium

Delirium can present with multiple symptoms which include delusions, hallucinations, depression and anxiety. These symptoms can cause distress and the behavioural response that the patient has to them can be varied and severe; examples include terror, a fight or flight response or withdrawal from the situation.  Remember that the person experiencing delirium may be very frightened and is having a normal response to an abnormal situation whether real or not. Unless dangerous for the patient or others, it is usually safer to allow supervised wandering. Non-Pharmacological management should be used in most cases.
Thinking about “behaviours that challenge” in terms of unmet need is a useful approach. Managing contributing factors to delirium as outlined previously is important. Systematically addressing potential causes of delirium, and finding out a person’s likes, dislikes and routines can help reframe “agitation” as a behaviour with an unmet need that needs to be addressed such as

  • Pain, urinary retention etc. (See PINCH ME approach above)
  • Boredom – provide meaningful activity, tailored to an individual’s preferences
  • Exercise e.g. I normally go for a walk at 4pm so may try to leave the ward
  • Reminiscence – looking through old photos or talking about past memories may help calm some people

Use the ‘This Is Me’ document to identify factors that may help or hinder care. Allowing carers open visiting may be helpful. LTHT is signed up to John’s campaign which asks for families and carers of patients to be invited to  stay with them in hospital for as many hours as needed and they are able to give.

[Grade C]

Drug Management of Distress and Agitation

Treatment for distress and agitation should be focused on the management of the underlying condition. Non-pharmacological approaches should be the benchmark for best practice. [Grade A]

However in some instances where there is severe distress and/or the patient’s behaviour is placing them or others in harms way, then pharmacological agents to try to minimise symptoms and/or sedate may be considered

Sedation may worsen confusion and increase falls. However it may be needed in the following situations:

  • In order to carry out essential investigations
  • To prevent harm to the patient or others
  • To relieve distress in highly agitated patients

In a situation where sedation is needed it is important to document your actions well. Things to be considered

  • Documentation of the capacity status of the patient
  • Diagnosis of the patient
  • Reasons why sedation is needed
  • Have the relatives been informed of the need for sedation - if not why not?
  • Aim to give medication orally - if needing IM medication then this needs to be clearly documented why in the medical notes.

When medications are needed, drug management in delirium encompasses two elements:

  • Rapid tranquilisation
  • Management of delirium over a longer period.

There is no role in using antipsychotics to prevent delirium.

Rapid Tranquilisation in Delirium

Note: When using haloperidol: Procyclidine should be immediately available to reduce risk of dystonia or other extrapyramidal side-effects. If dystonia occurs then give procyclidine i/m or i/v as per manufacturer’s instruction.

[Grade C]

Management of delirium over a longer period
When a patient’s behaviour or distress is on-going they may need medication to help manage their symptoms for a period of a few days. In this case treatment should be considered but only commenced by a specialist in delirium such as a care of the elderly physician or psychiatrist. Drugs which may be considered are:

Risperidone usually 0.5mg OD
Olanzapine typically 2.5mg OD
Haloperidol usually 0.5-1.25mg OD
Lorazepam typically 0.5mg OD
Quetiapine 25mg nocte (for hallucinations and delusions in the context of Parkinson’s disease or Lewy Body Dementia)

Antipsychotics are preferred to sedatives if hallucinations are a predominant feature. If a patient needs regular drug management, a referral should be made to liaison psychiatry for on-going advice and support.

Given the risk of cardiac side effects with antipsychotics, regular ECGs should be done to look for QTC prolongation. If the QTC is >450 in men or >470 in women antipsychotics should be avoided.

Please be aware that common side effects of antipsychotics include sedation, increased risk of falls and a slightly increased risk of a stroke. This increased risk should be explained to the patient’s family

The Golden Rules when prescribing are:

  • Use only one drug if at all possible
  • Start with the lowest possible dose
  • Given orally wherever possible
  • Allow sufficient time for drug to act
  • Don’t exceed maximum doses as stated in the BNF
  • Review need for medication every 24 hours and discontinue as soon as possible
  • Inform next of kin of treatment decisions and the rationale for them.

[Grade C]

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Legal Aspects of Delirium

If a patient does not have the capacity to make a decision about treatment then the decision to treat should be made using the process of Best Interests decision making under the Mental Capacity Act of 2005.  It is crucial to document your capacity assessment and best interest’s decision - this can be entered as a clinical document on PPM. Where possible this should be communicated with the patient’s next of kin.

Under the Mental Capacity Act 2005, someone lacks capacity to make a decision when they have an impairment or disturbance in the functioning of the mind and brain and are unable to:

  • Understand information about the decision to be made
  • Retain information about the decision to be made
  • Use or weigh that information as part of the decision-making process
  • Communicate their decision.

If restraint is needed in order to administer medications or for any other reason, then for someone who lacks capacity to consent you should follow the principles of the Mental Capacity Act. This means the restraint must be necessary to prevent harm, and proportionate to the likely harm.  You should demonstrate that this is the case by documenting it.  If restraint is prolonged or being used repeatedly then the Mental Health Act should be considered.

Deprivation of Liberty
If the patient is assessed as lacking the capacity to make the decision to consent to hospital admission then a Deprivation of Liberty safeguard (DOLs) needs to be applied for. Please review LTHT Deprivation of Liberty Safeguards standard operating procedure if you are not familiar with the use of DOLS.

Giving medications against a patient’s will (whether orally or intramuscularly), especially using restraint, is a strong indicator that someone is being deprived of their liberty. Where someone is deprived of their liberty, there must be a legal power (deprivation of liberty safeguards (DoLS) or the Mental Health Act) to authorise the detention.  The Mental Capacity Act allows for restraint and emergency treatment under certain circumstances; however for persistent situations where medication is repeatedly given against someone’s will and/or restraint occurs repeatedly, it is very important to urgently consider which legal framework applies. In practice the Mental Health Act should be used for persistent situations where a patient is objecting to the treatment they are being given and/or their admission.  Referral to liaison psychiatry for assessment in this situation is advised.

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Liaison Psychiatry

The Liaison Psychiatry team can provide advice and assessment of patients. They should be contacted in the following circumstances:

  • Patients who have significant behavioural symptoms requiring medication or posing a risk to themselves or others.
  • You must refer patients if they have required 2 or more administrations of sedative medications.
  • When the diagnosis is unclear
  • To provide a second opinion for difficult Mental Capacity decisions
  • Delirium which is slow to resolve 

Contact details:
Age 65 years and over: Liaison Psychiatry for Older People: 0113 2067147

Patients under 65:
SJUH 0113 8556730
LGI 0113 392 3204 

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Discharge and Follow up

Communication with GP’s

  • The EDAN should contain
    • Clear documentation of the diagnosis of delirium and its precipitants
    • Symptoms at the time of discharge
    • 4AT score
    • Follow up arrangements

Follow up

The resolution of delirium can be assessed by considering whether there is clinical improvement (often best assessed by someone that knows the patient well) and by repeating a 4AT to assess attention and memory.

It is possible for delirium to be the first presentation of undiagnosed dementia. It is therefore vital that patients are followed up post discharge for cognitive and functional reassessment. 

Follow up may take several forms:

  • The responsible consultant may arrange follow up in out-patients clinic. 
  • The liaison psychiatry team may arrange follow up with community mental health teams - they will inform you of this, please make the GP aware in the EDAN. 
  • If there is no immediate need for community mental health team follow up it is reasonable to ask the GP to reassess the patient after a few weeks and consider memory service follow up if required. 

Communication with patient and families

  • Ensure the patient and family are aware of the diagnosis
  • Inform them of the risk of future episodes of delirium and to observe for early warning signs and seek medical attention if seen.

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Further Resources

Think Delirium. Yorkshire and The Humber Clinical Networks.
SIGN 157. Risk reduction and management of delirium
NICE CG 103.
Delirium video

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Appendix 1

4AT guidance notes

The 4AT is a screening instrument designed for rapid and sensitive initial assessment of cognitive impairment.

Items 1-3 are rated solely on observation of the patient at the time of assessment.

Item 4 requires information from one or more sources, for example your own knowledge of the patient, other staff who know the patient (for example ward nurses), GP letter, case notes, carers. The tester should take account of communication difficulties (hearing impairment, dysphasia, lack of common language) when carrying out the test and interpreting the score.

A score of 4 or above suggests delirium but is not diagnostic: more detailed assessment of mental status may be required to reach a diagnosis.

A score of 1-3 suggests cognitive impairment and more detailed cognitive testing and informant history-taking are required.

A score of 0 does not definitively exclude delirium or severe cognitive impairment: more detailed testing may be required depending on the clinical context.

Alertness: Altered level of alertness is very likely to be delirium in general hospital settings. If the patient shows significant altered alertness during the bedside assessment, score 4 for this item.

AMT4 (Abbreviated Mental Test - 4): This score can be extracted from items in the AMT10 if the latter is done immediately before.

Attention: the Months Backwards test assesses attention, the main cognitive deficit in delirium; most patients with delirium will show deficits. Other types of cognitive impairment, for example dementia, can also lead to deficits on this test.

Acute change or fluctuating course: Fluctuation can occur without delirium in some cases of dementia, but marked fluctuation usually indicates delirium. To help elicit any hallucinations and/or paranoid thoughts ask the patient questions such as, "Are you concerned about anything going on here?"; "Do you feel frightened by anything or anyone?"; "Have you been seeing or hearing anything unusual?"

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Record: 4699

To provide evidence-based recommendations to aid diagnosis, investigation and management of delirium in hospitalised adults in Leeds Teaching Hospitals NHS Trust (LTHT). It does not apply to delirium caused by alcohol or drug intoxication or withdrawal (in whom separate guidance is available). Nor does it apply to those receiving care in the last days of life or those in critical care units , for who separate guidance exists.

Clinical condition:


Target patient group: All patients admitted to Leeds Teaching hospitals NHS Trust
Target professional group(s): Secondary Care Doctors
Allied Health Professionals
Secondary Care Nurses
Adapted from:

Evidence base

Not supplied

Approved By

Trust Clinical Guidelines Group

Document history

LHP version 2.2

Related information

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Equity and Diversity

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