14.1 Delirium Recognition, the 4AT & Acute Confusion
Key Takeaways
- RCSI lists Delirium as a topic heading citing the 4AT screening tool and NICE guidance, and names delirium as a current example for both the nursing process in the acute situation and older person care OSCE stations.
- The 4AT has four items: alertness scored 0 or 4, AMT4 scored 0 to 2, months of the year backwards scored 0 to 2, and acute change or fluctuating course scored 0 or 4, giving a maximum of 12.
- A 4AT score of 4 or more suggests possible delirium, 1 to 3 suggests possible cognitive impairment, and 0 makes delirium or severe cognitive impairment unlikely; the tool screens rather than diagnoses.
- Hypoactive delirium is the commonest form in older inpatients and the most frequently missed, because a quiet, withdrawn, drowsy patient does not disrupt the ward.
- Management is to find and treat the cause, using the PINCH ME prompt, and to apply non-pharmacological measures first; sedation is a last resort for severe distress or risk and never a substitute for identifying the trigger.
Delirium Recognition, the 4AT & Acute Confusion
RCSI lists Delirium as a topic heading with the 4AT screening tool and NICE delirium guidance, and names delirium as a current example for two station groups: nursing process in the acute situation and older person care. It is also one of the conditions where nursing recognition changes outcomes most directly.
Delirium affects a large proportion of older inpatients and is associated with falls, longer stay, loss of independence, new admission to long-term care, persistent cognitive decline and increased mortality. It is frequently the first sign of an acute physical illness - the infection, the retention, the hypoxia or the drug that nobody has yet found.
Definition and Core Features
Delirium is an acute, fluctuating disturbance of attention and awareness, accompanied by a change in cognition, that develops over hours to days and is caused by an underlying physiological disturbance.
The four features that define it:
- Acute onset - over hours to days, and a clear change from the person's baseline.
- Fluctuating course - worse at night and in the late afternoon (sundowning), with lucid intervals that can mislead an assessor who visits once.
- Inattention - the cardinal feature. The person cannot sustain or shift attention, loses the thread of a sentence, and is easily distracted.
- Disorganised thinking or altered consciousness - rambling speech, illogical flow, hyperalertness or drowsiness.
The Three Subtypes
| Subtype | Presentation | Risk |
|---|---|---|
| Hyperactive | Agitation, restlessness, hallucinations, pulling at lines and catheters, wandering, aggression | Readily recognised - and often the only type staff think of as delirium |
| Hypoactive | Withdrawn, quiet, drowsy, slow to respond, reduced appetite, apparent low mood | The commonest form in older inpatients and the most often missed. A quiet patient disturbs nobody, so nobody investigates |
| Mixed | Fluctuates between the two | Easily misread as improvement during the quiet phase |
The single most useful clinical habit: a newly quiet, withdrawn older patient is a screening trigger, not a well-behaved patient.
The 4AT
The 4AT is a rapid bedside screening tool for delirium and cognitive impairment. It takes about two minutes, needs no special training and can be completed even in a drowsy or uncooperative patient - untestable items score positive rather than being left blank.
| Item | What it assesses | Scoring |
|---|---|---|
| 1. Alertness | Observed level of alertness, including drowsiness or agitation | 0 normal; 4 clearly abnormal alertness |
| 2. AMT4 | Age, date of birth, place (name of the hospital or building), current year | 0 no mistakes; 1 one mistake; 2 two or more mistakes or untestable |
| 3. Attention | Ask the person to recite the months of the year backwards, starting at December | 0 achieves 7 months or more correctly; 1 starts but scores fewer than 7 months, or refuses; 2 untestable (cannot start because unwell, drowsy or inattentive) |
| 4. Acute change or fluctuating course | Evidence of significant change or fluctuation in alertness, cognition or other mental function over the last 2 weeks and still evident in the last 24 hours | 0 no; 4 yes |
Maximum score: 12.
Interpreting the Score
| Total | Interpretation |
|---|---|
| 4 or more | Possible delirium, with or without cognitive impairment |
| 1 to 3 | Possible cognitive impairment - delirium is less likely but not excluded; further assessment needed |
| 0 | Delirium or severe cognitive impairment unlikely, though delirium is still possible if item 4 information is incomplete |
Two cautions that matter clinically:
- The 4AT screens; it does not diagnose. A score of 4 or more prompts fuller assessment and a search for the cause, not a label.
- Collateral history is essential for item 4. Without knowing the person's baseline, you cannot judge acute change. Ask the family, the nursing home, the GP or the public health nurse - and record where the information came from.
Repeat the 4AT to track the course. A single score is a snapshot of a fluctuating condition.
Delirium, Dementia and Depression
| Feature | Delirium | Dementia | Depression |
|---|---|---|---|
| Onset | Acute, hours to days | Insidious, months to years | Weeks to months |
| Course | Fluctuating, worse at night | Slowly progressive, stable within a day | Relatively stable, often worse in the morning |
| Attention | Markedly impaired | Preserved until late | Mildly reduced; may be distractible |
| Consciousness | Altered - drowsy or hyperalert | Clear until late | Clear |
| Reversibility | Usually reversible if the cause is treated | Not reversible | Treatable |
| Answers to questions | Incoherent, rambling | Confabulation, near-miss answers | "I don't know", poor effort |
They are not mutually exclusive. Dementia is the strongest single risk factor for delirium, and delirium superimposed on dementia is common and easily dismissed as "just her dementia". Any acute change from the person's usual dementia baseline is delirium until proven otherwise.
Finding the Cause: PINCH ME
Delirium is a symptom. The nursing task is to help find the cause, and PINCH ME is a reliable prompt:
| Letter | Cause | What to check |
|---|---|---|
| P | Pain | Untreated or under-treated pain, especially in someone who cannot report it - use a behavioural pain tool |
| I | Infection | Urinary tract infection, chest infection, cellulitis, line infection. Screen for sepsis where INEWS triggers |
| N | Nutrition | Poor intake, dehydration, thiamine deficiency, electrolyte disturbance |
| C | Constipation | Faecal impaction is a genuine and commonly missed precipitant |
| H | Hydration | Dehydration, hypovolaemia, acute kidney injury |
| M | Medication | New drugs, opioids, anticholinergics, benzodiazepines, and equally withdrawal from alcohol, nicotine or benzodiazepines |
| E | Environment / Electrolytes | Ward moves, sensory deprivation, sleep disruption; sodium, calcium, glucose |
Add to that: hypoxia, urinary retention, recent surgery and anaesthesia, stroke, head injury, and pain from an unrecognised fracture.
Investigations commonly include a full observation set with INEWS, capillary glucose, urinalysis, bloods including full blood count, urea and electrolytes, calcium, liver and thyroid function, an ECG, a bladder scan for retention, and a chest X-ray or CT brain as clinically indicated.
Management: Non-Pharmacological First
The evidence base is clear that the mainstay of delirium care is environmental and relational, not pharmacological.
| Domain | Interventions |
|---|---|
| Orientation | Reorientate gently and repeatedly; a visible clock and calendar; introduce yourself each time; explain where the person is and why |
| Sensory | Glasses on, hearing aids in and working. Sensory deprivation both causes and worsens delirium, and this is the cheapest intervention available |
| Consistency | Minimise ward and bed moves; consistent staff where possible; familiar objects and photographs from home |
| Family | Encourage presence and open visiting; family notice changes first and provide the baseline you need |
| Sleep | Protect night-time sleep: lower lighting and noise, cluster observations, avoid non-urgent nocturnal interventions, natural light and activity by day |
| Mobility | Get the person up and walking as able; avoid unnecessary catheters, lines and restraints, all of which tether a confused person to the bed |
| Physiology | Treat pain, hydrate, feed, treat constipation, correct hypoxia, review every medicine |
| Safety | Falls risk assessment, bed at lowest height, call bell in reach, appropriate footwear, calm and uncluttered environment |
| Communication | Short sentences, one instruction at a time, face the person, allow time, do not argue with or contradict a delusion - acknowledge the feeling and redirect |
Medication is a last resort. Where a person is severely distressed or poses an immediate risk to themselves or others and non-pharmacological measures have failed, short-term low-dose medication may be prescribed - but it treats the behaviour, not the delirium, and it carries risks of falls, sedation, aspiration and prolonged confusion. It is never a substitute for finding the cause.
Restraint - physical, chemical or environmental - requires a clear legal and ethical justification, must be the least restrictive option, must be time-limited, reviewed and documented, and must comply with the Assisted Decision-Making (Capacity) Act 2015 and national policy on restrictive practice.
Documentation, Escalation and Family
- Document the 4AT score and the items that generated it, along with the collateral source for item 4.
- Escalate promptly: new delirium is a change in condition that requires medical review and a search for the cause.
- Use ISBAR - "Mrs Byrne's 4AT has gone from 0 on admission to 6 this morning, she is newly confused and has not passed urine for eight hours; I would like her reviewed within the hour and a bladder scan."
- Explain to the family. Delirium is frightening to watch. Explain that it is usually caused by a physical illness, that it commonly fluctuates, that it usually improves as the cause is treated but may take weeks, and that their presence and familiar objects genuinely help. Involve them in the care.
An 82-year-old woman two days after hip surgery is drowsy, withdrawn and slow to answer, where she was alert and chatty on admission. A nurse records 'settled, no concerns'. What is the error?
A patient scores: alertness clearly abnormal (4), two errors on the AMT4 (2), unable to attempt months of the year backwards because too drowsy (2), and a documented acute change over the past 24 hours (4). What is the total 4AT score and what does it mean?
A patient with delirium is agitated and repeatedly trying to climb out of bed. Which approach should be taken first?