Which tool does NICE recommend for diagnosing delirium?

NICE CG103, last updated in January 2023, asks a practitioner competent to do so to carry out an assessment using the 4AT tool. In critical care, or in the recovery room after surgery, CG103 asks for the CAM-ICU or the Intensive Care Delirium Screening Checklist instead.

Who is at risk of delirium according to NICE?

NICE CG103 lists four risk factors to assess at first presentation: age 65 years or older, cognitive impairment or dementia past or present, current hip fracture, and severe illness meaning a condition that is deteriorating or at risk of deterioration. Any one of them means the person is at risk.

Why is hypoactive delirium easy to miss?

NICE CG103 describes hypoactive delirium as a subtype where people become withdrawn, quiet and sleepy, and asks staff to be particularly vigilant for it. The signs it lists, such as slow responses, reduced mobility and reduced appetite, are easily read as a patient who is simply tired after an operation.

How do you tell delirium from dementia in a post-operative patient?

Delirium is recent, within hours or days, and fluctuates, whereas dementia is chronic and progressive. NICE CG103 answers the difficult case directly: if there is difficulty distinguishing delirium, dementia or delirium superimposed on dementia, manage the delirium first.

What should happen if post-operative delirium does not resolve?

NICE CG103 asks you to re-evaluate for underlying causes and to follow the person up and assess for possible dementia. It also asks that the diagnosis of delirium is documented both in the hospital notes and in the primary care record so that the follow-up actually happens.

Can a patient with delirium consent to an operation?

Capacity is decision-specific and time-specific, so a delirious patient may lack capacity for one decision and retain it for another. The delirium itself does not remove capacity automatically, and a formal assessment with a best-interests process is required if capacity is absent.

Post-operative Delirium — CST Interview Clinical Station Answer

Q: When is haloperidol appropriate in post-operative delirium?

NICE CG103 asks for verbal and non-verbal de-escalation first for a patient who is distressed or a risk to themselves or others. Only if those techniques are ineffective or inappropriate does it ask you to consider short-term haloperidol, usually for one week or less, at the lowest clinically appropriate dose with cautious titration.

Post-operative confusion and delirium is an acute, fluctuating disturbance of cognition, perception, physical function or social behaviour developing over hours or days after an operation. According to NICE clinical guideline CG103, published on 28 July 2010 and last updated on 18 January 2023, a patient with indicators of delirium should be assessed with the 4AT tool, and in critical care or in the recovery room after surgery with the CAM-ICU or ICDSC instead. At the CST station, delirium is a search for a cause, not a prescription.

Key takeaways

NICE CG103 names four risk factors for delirium at first presentation to hospital: age 65 years or older, cognitive impairment or dementia, current hip fracture, and severe illness
CG103 asks for people at risk to be assessed within 24 hours of admission for clinical factors contributing to delirium, followed by a tailored multicomponent intervention
The assessment tool in CG103 since the 2023 update is the 4AT, with the CAM-ICU or ICDSC used instead in critical care and in the recovery room after surgery
CG103 tells you to be particularly vigilant for hypoactive delirium, which is often missed and shows as withdrawal, slow responses, reduced mobility and reduced appetite
For a distressed patient, CG103 requires verbal and non-verbal de-escalation first, and only then consideration of short-term haloperidol, usually for one week or less, starting at the lowest clinically appropriate dose
If delirium does not resolve, CG103 asks you to re-evaluate for underlying causes and to follow up and assess for possible dementia

How do I recognise post-operative delirium?

Recognise post-operative delirium as a recent change or fluctuation, within hours or days, in cognitive function, perception, physical function or social behaviour, which is exactly the list NICE CG103 uses.

CG103 gives examples for each. Worsened concentration, slow responses and confusion for cognition. Visual or auditory hallucinations for perception. Reduced mobility, restlessness, agitation, appetite change and sleep disturbance for physical function.

The change is often reported by a relative or a nurse rather than found by you. CG103 says these changes may be reported by the person at risk, or by a carer or relative, so take that history seriously.

Who is at risk of post-operative delirium?

NICE CG103 asks you to assess everyone presenting to hospital for four risk factors, and any one of them means the patient is at risk of delirium: age 65 years or older, cognitive impairment or dementia, current hip fracture, and severe illness.

Severe illness is defined in CG103 as a clinical condition that is deteriorating or is at risk of deterioration, which describes most emergency surgical admissions. CG103 also asks you to observe for changes in those risk factors at every opportunity.

For a surgical trainee, that list is close to a description of the emergency take. A frail patient with a fractured neck of femur ticks three boxes before they reach the ward.

What is my immediate A to E approach to a confused post-operative patient?

Approach a confused post-operative patient with A to E first, because hypoxia, hypoglycaemia, hypotension and sepsis all present as delirium and all are found in the primary assessment.

Check the airway, the respiratory rate and the saturations, then the blood pressure and perfusion, then a capillary glucose. NICE CG103 asks you to assess for hypoxia and to optimise oxygen saturation as clinically appropriate.

CG103 also warns that some pulse oximeters can underestimate or overestimate oxygen saturation, especially at borderline levels, with overestimation reported in people with dark skin. Say that, because it shows you read the guideline rather than a summary.

How do I confirm the diagnosis of post-operative delirium?

Confirm post-operative delirium with a formal tool. NICE CG103 says a health or social care practitioner competent to do so should carry out an assessment using the 4AT, and should use the CAM-ICU or ICDSC in critical care or in the recovery room after surgery.

CG103 then asks a healthcare professional with the relevant expertise to make the final diagnosis, which may be the same person who did the assessment. It also asks you to document the diagnosis in the notes and in the primary care record.

If delirium and dementia cannot be separated, CG103 is clear: manage the delirium first. That single line answers the follow-up question the panel most often asks about a patient with known dementia.

What causes post-operative delirium, and how do I investigate it?

Post-operative delirium is almost always multifactorial, so investigate every contributing factor rather than settling on the first one, which is the logic behind the multicomponent package in NICE CG103.

Infection, including a surgical site infection, a collection, pneumonia or a urinary tract infection
Pain, which CG103 asks you to assess for actively, including non-verbal signs in people who cannot report it
Drugs, including opioids and anticholinergics, with CG103 asking for a medication review in anyone on multiple drugs
Dehydration and constipation, hypoxia, electrolyte disturbance and alcohol or benzodiazepine withdrawal
Urinary retention and an avoidable catheter, since CG103 asks you to avoid unnecessary catheterisation

Investigations follow the list. Bloods including inflammatory markers, electrolytes, calcium and glucose, a urine dipstick interpreted with care in older people, a chest radiograph if indicated, and imaging only when a surgical cause is suspected.

What is the management of post-operative delirium?

The management of post-operative delirium is to identify and treat the underlying cause or causes, and then to deliver the tailored multicomponent intervention that NICE CG103 sets out.

CG103 asks for the intervention package to be given within 24 hours of admission for those at risk, delivered by a multidisciplinary team trained and competent in delirium prevention, and tailored to the individual and the setting.

The package addresses orientation and lighting, dehydration and constipation, hypoxia, infection, immobility, pain, polypharmacy, nutrition, sensory impairment and sleep. CG103 also asks that people at risk are cared for by familiar staff and not moved between wards unless absolutely necessary.

For a surgical patient, two of those items are concrete: encourage people to mobilise soon after surgery, and ensure hearing aids and glasses are present and working.

When is sedation appropriate in post-operative delirium?

Sedation is a last step in post-operative delirium. NICE CG103 says that if a person with delirium is distressed or considered a risk to themselves or others, you first use verbal and non-verbal techniques to de-escalate the situation.

Only if those techniques are ineffective or inappropriate does CG103 ask you to consider giving short-term haloperidol, usually for one week or less, starting at the lowest clinically appropriate dose and titrating cautiously according to symptoms.

CG103 directs you to the MHRA advice on the risks of haloperidol for acute delirium in older people, including cardiac and neurological side effects, especially in people living with Parkinson's disease or dementia with Lewy bodies.

CG103 also notes that distress may be less evident in hypoactive delirium, where the patient can still be distressed by psychotic symptoms while appearing quiet.

Who do I escalate post-operative delirium to, and when?

Escalate post-operative delirium to your surgical registrar whenever the confusion might be a surgical complication, and to the medical, geriatric or perioperative medicine team for the multicomponent management.

Escalate urgently for a reduced conscious level, new focal neurology, a rising early warning score, or an A to E abnormality you cannot correct. Delirium plus hypotension in a post-operative patient is sepsis until disproved.

Involve the family early. NICE CG103 asks you to offer information explaining that delirium is common and usually temporary, and to encourage relatives to report sudden changes or fluctuations in behaviour.

What is the interviewer listening for in a post-operative delirium scenario?

The interviewer in a post-operative delirium scenario is listening for a candidate who treats confusion as a symptom of surgical disease, uses a named tool, and reaches for sedation last rather than first.

A to E before any cognitive assessment, with glucose, saturations and blood pressure stated
The 4AT named, with the CAM-ICU or ICDSC named for critical care and the recovery room
Hypoactive delirium named as the form that gets missed
De-escalation offered before haloperidol, with the short-term wording and the Lewy body caution
Capacity, safeguarding and a clear plan to talk to the family

What are the common mistakes in a post-operative delirium answer?

The common mistake in a post-operative delirium answer is prescribing sedation as the first move, which inverts the order NICE CG103 sets out and tells the panel you would sedate an undiagnosed surgical complication.

The second is treating an asymptomatic positive urine dipstick in an older patient as the answer, when the leak, the collection or the chest is the real cause.

The third is forgetting capacity. A delirious patient may lack capacity for a specific decision, and that requires an assessment and a best-interests process rather than an assumption in either direction.

How this comes up at the CST interview

Post-operative delirium usually arrives as a night call about an older patient pulling at their drain or their catheter two days after a hemiarthroplasty, with the nurse asking for something to calm them.

The panel then pushes on the sedation question, on capacity and restraint, or on what you would do if the confusion turned out to be the first sign of sepsis.

Delirium scenarios also test communication, because the family conversation is part of the mark. The coresurgeryinterview question bank includes scored versions among its 299 questions, with AI-marked spoken practice: /Question-Bank/Sample-Questions.

Post-operative Confusion and Delirium