Acute confusion, otherwise known as delirium, is very common in hospitals: 20-30% on medical wards, and between 10-50% of those that have surgery develop delirium.

Our Webinar

YouTube player

Types of Delirium

  1. Hyperactive – agitated, delusions, hallucinations, aggression
  2. Hypoactive – harder to spot – lethargy, psychomotor retardation, excessive sleeping, inattention – often misdiagnosed as depression
  3. Mixed

Predisposing factors

  • Previous history of delirium
  • Age (>65 years) & it is more common in males
  • Dementia
    • Delirium on dementia is common. To know whether a patient may have delirium on top, you can check their AMTS against their baseline in combination with the 4AT
    • Other “geriatric syndromes”: falls, elder abuse, malnutrition, polypharmacy, social isolation
  • Comorbidities
    • alcoholism
    • chronic pain
    • history of baseline lung, liver, kidney, heart or brain disease
    • terminal illness
  • Poor functional state or frailty
    • pressure ulcers
    • premorbid state
    • inactivity


A commonly used mnemonic is PINCH ME

Another mnemonic is DELIRIUM

  • D- drugs, dehydration, detox (alcohol)
  • E- electrolytes (hypercalcaemia, hyponatraemia), environment (esp ICU)
  • L- lack of sleep
  • I- infection, infarction
  • R- renal failure
  • I- intoxication, impaction (constipation)
  • U- UTI
  • M- metabolic (hypoglycaemia, thyroid), malignancy (cerebral/paraneoplastic)


  • Guided by history and examination, collateral history is invaluable where possible
  • AMTS can be a quick confusion ‘screening test’ and repeated to show improvement – consider MMSE/ACE)
  • Observations can lead to the underlying cause (e.g.: temperature suggesting infection, tachycardia – infection, dehydration or pain)
  • Bloods:
    • FBC
    • U&E
    • LFTs
    • Glucose
    • TFTs
    • Calcium
    • Haematinics
    • Blood cultures (if sepsis suspected)
  • Imaging:
    • CT head – consider in patients with no other identifiable reasons, with focal neurology, history of falls/anticoagulation, worsening or prolonged delirium, drowsiness
    • CXR – as part of infection/sepsis screen
  • Urine MC&S
    • Never rely on nitrites/leukocytes on a urine dip which will be positive in up to 50% of patients without a UTI
    • Send the urine in any patient who is delirious and consider empirical treatment (particularly if there is other evidence to support the diagnosis e.g. raised WCC, suprapubic tenderness, dysuria, frequency etc)


  • Treat the underlying cause
  • Treatment is mostly supportive:
    • Consistent team, re-orientation and reassurance, regularly introduce yourself and your role
    • Familiar objects, e.g.: photos, books, music, clothes. Family can help with providing care which helps
    • Clear and concise communication
    • Make sure they have their hearing aids/glasses/walking stick etc
    • Try to maintain/encourage regular sleep – minimise waking through night, keeps lights off overnight etc
  • Medication
    • Avoid unless necessary (such as if they are at risk to themselves or others)
    • Drugs can worsen delirium – consider stopping benzodiazepines or sedating drugs which could precipitate delirium
    • Low dose haloperidol (0.5mg) is first-line – PO or IM usually
    • Lorazepam (0.5mg) often used if haloperidol is contraindicated (e.g.: heart issues, Parkinson’s, Lewy body)
  • Time – often family/staff want delirium to be “cured” with a tablet because they don’t have the staff to constantly watch patients.
    • Offer reassurance that delirium will settle but that this can take time, even post-discharge, and that supportive management is the best management
    • Let them know that delirium is often much better at home in a familiar environment. Keeping a patient in hospital because they are delirious can sometimes be harmful
    • Give them a leaflet
  • Always put the diagnosis of delirium on the discharge summary
    • Recurrent delirium is suggestive that the patient could be at risk of dementia, prompting closer observation and consideration of memory clinic referral

Further Reading

By Emma Brooks CT1 (Psychiatry)

How useful was this post?

Click on a star to rate it!

Average rating 5 / 5. Vote count: 28

No votes so far! Be the first to rate this post.

As you found this post useful...

Follow us on social media!

We are sorry that this post was not useful for you!

Let us improve this post!

Tell us how we can improve this post?

Related Posts

A pneumothorax is defined as the abnormal collection of air between...
As an FY1 in hospital, you will come across lots of patients...
Sepsis is an infection with evidence of organ dysfunction. Septic...

2 thoughts on “Delirium”

Leave a Comment

Your email address will not be published. Required fields are marked *

Follow us



Trending Now

Doctor's Pay Calculator 2024
We’ve created a pay calculator to help you better understand your salary, how much tax you’ll...
Paracetamol Overdose
Paracetamol overdose is a common presentation in A&E and so you may often find yourself looking after...
Understanding the MSRA
The Multiple Specialty Recruitment Assessment (MSRA) is a computer-based exam increasingly being used...
How to take a psychiatric history
Psychiatry, as a specialty is unique in that diagnostic methods, rely very heavily on symptomatology,...
Common Viral Infections (exanthem) in Paediatrics
Viral infections are extremely common in paediatrics and a common presentation to paediatric A&E...
Abdominal X-rays
The advantages of AXRs are far less radiation to patients & that they’re logistically easy...
Essential Apps
Here’s a list of apps that are in order of how essential we find them. There’s probably more...

Sign up for our awesome resources

Join over 40,000 users who have signed up for our free weekly webinars, referral cheat sheet & other exclusive content!