Recognising Delirium for Student Nurses
Learn how delirium may present, why sudden changes in attention and cognition matter, and how to connect altered mental state with the patient's wider clinical condition.
What can delirium look like?
Delirium can affect attention, awareness, thinking and behaviour. Presentation can vary significantly between patients and can change over relatively short periods.
Difficulty concentrating
The patient may struggle to follow conversation, stay focused or complete simple tasks.
Reduced understanding of surroundings
They may become unsure where they are or what is happening around them.
Disorganised cognition
Conversation may become difficult to follow or responses may seem inconsistent.
Agitation or restlessness
Some patients become visibly unsettled, distressed or unusually active.
Quiet deterioration matters too
Others become drowsy, slow to respond, less interactive or unusually withdrawn.
Hallucinations may occur
The patient may report seeing or hearing things that other people do not experience.
Hyperactive, hypoactive and mixed presentations
Delirium is not always the visibly agitated state people often imagine. A quieter presentation can be particularly easy to miss.
Restless or agitated
The patient may be unsettled, distressed, repeatedly trying to move or interfering with treatment.
Quiet and withdrawn
The patient may appear unusually sleepy, slow, inattentive or less engaged with their surroundings.
The presentation may fluctuate
A patient may alternate between more active and more withdrawn periods.
Establish what is new
Know the usual cognition
Establish how the patient normally communicates, behaves and functions.
Identify onset
Determine when the cognitive or behavioural change first became apparent.
Look for fluctuation
Ask whether the patient's cognition has varied during the shift or over recent hours.
Describe specific change
Record what you observed rather than relying only on labels such as “confused”.
Existing dementia or cognitive impairment does not prevent a patient from developing delirium as an additional acute problem.
Look for what may be driving the delirium
Delirium is often a sign of another clinical problem. Assessment should therefore focus on the whole patient rather than cognition alone.
Look for acute illness
Infection can be associated with delirium, particularly in vulnerable patients.
Assess oxygenation
Respiratory compromise can contribute to altered cognition and reduced alertness.
Consider physiological disturbance
Glucose abnormalities and other metabolic problems may contribute to cognitive change.
Review the medication picture
New medicines, dose changes, interactions or withdrawal may be clinically relevant.
Check for discomfort
Pain can contribute to distress, altered behaviour and reduced function.
Consider intake and fluid balance
Dehydration and poor intake may contribute to deterioration.
Urinary problems may matter
Urinary retention and other uncomfortable physical problems should not be overlooked.
Review bowel function
Constipation can contribute to discomfort and altered behaviour in vulnerable patients.
Look for neurological change
Stroke, seizures, head injury and other neurological problems may present with altered cognition.
Start with physiological assessment
Airway
Confirm the airway is patent and identify any immediate threat.
Breathing
Assess respiratory rate, oxygen saturation, breathing pattern and work of breathing.
Circulation
Assess pulse, blood pressure, perfusion and relevant fluid-balance information.
Disability
Assess consciousness, new confusion, neurological findings and blood glucose when clinically appropriate.
Exposure
Look for fever, infection, injury, pain, retention and other possible contributors while maintaining dignity.
Escalate
Communicate new cognitive change and associated deterioration promptly.
Simple nursing actions can reduce distress
Speak calmly and clearly
Introduce yourself, explain what is happening and avoid overwhelming the patient with multiple instructions.
Provide helpful cues
Clocks, calendars, familiar objects and simple reminders can support orientation where appropriate.
Check glasses and hearing aids
Reduced vision or hearing can make an unfamiliar environment more confusing.
Support appropriate intake
Ensure hydration and nutrition plans are followed safely and report difficulties.
Reduce unnecessary disruption
Support normal sleep and wake patterns where clinically possible.
Assess individual risks
Consider falls, mobility, treatment equipment and the level of supervision required.
When delirium requires urgent escalation
- Rapidly developing or worsening cognitive change.
- Reduced or deteriorating level of consciousness.
- New focal neurological signs.
- Significant hypoxia or respiratory deterioration.
- Hypotension or other evidence of circulatory compromise.
- Suspected severe infection or systemic deterioration.
- Significant glucose abnormality or other acute metabolic problem.
- Delirium following seizure or head injury.
- Any presentation where the patient appears seriously unwell.
A quiet patient becomes unusually withdrawn
Example
A patient who was talking normally with staff yesterday is now very quiet, struggles to maintain attention and repeatedly falls asleep during conversation.
Their relative confirms this is completely different from normal. Their respiratory rate and temperature are also elevated.
You recognise the pattern: acute cognitive change + reduced attention + change from baseline + physiological deterioration.
You assess the patient systematically, report the new presentation and escalate promptly rather than assuming that delirium must involve obvious agitation.
Describe the change clearly
Example escalation
“I'm concerned about Mrs Ahmed. Yesterday she was alert and having normal conversations. Today she is unusually drowsy, cannot maintain attention and repeatedly loses track of what is being discussed. Her family says this is completely different from baseline, and her respiratory rate and temperature have also increased.”
This communicates the baseline, acute change, attention deficit, associated observations and overall deterioration.
Delirium recognition errors to avoid
- Assuming delirium always causes agitation.
- Missing hypoactive delirium because the patient seems quiet.
- Assuming dementia explains every cognitive change.
- Failing to establish the patient's usual baseline.
- Using “confused” without documenting specific findings.
- Ignoring physiological observations and ABCDE assessment.
- Focusing only on behaviour rather than possible underlying illness.
- Delaying escalation while waiting for the patient to become more obviously unwell.
Recognise → compare → investigate → escalate
Notice altered attention and cognition
Look for agitation, withdrawal, disorientation, inattention and changes in behaviour or function.
Establish baseline and assess the patient
Determine what is new and look systematically for physiological, neurological and other possible causes.
Report the whole pattern
Describe the cognitive change, timing, baseline and associated deterioration clearly.
Delirium is often a sign of something else
Build confidence by recognising acute changes in attention and cognition, establishing the patient's normal baseline and looking for the underlying physiological or neurological problem.
Explore Clinical Confidence →