An Older Adult With Confusion After a Fall: Delirium or Dementia?
An 82-year-old woman is brought to the community clinic by her daughter after a fall at home. The daughter says her mother has been 'not herself' for two days - she is drowsy by day, awake and agitated at night, and has been seeing 'people in the room' who are not there. Previously she lived alone, managed her own medication and finances, and walked to the shops daily. On assessment she is oriented to person only, cannot recall three objects after one minute, and is picking at her bedclothes. Temperature is 38.1 C, pulse 104/min, BP 132/78 mmHg, SpO2 93% on room air, and respiratory rate 22/min. She has a bruised left forearm from the fall. The daughter asks whether this is 'just old age' and whether she should take her home.
1. Distinguish between delirium and dementia in this presentation and justify your conclusion with the specific features described.
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Conclusion: this is delirium, not dementia.
Features that point to delirium:
- Acute onset over two days - delirium develops over hours to days; dementia develops over months to years.
- Fluctuating course - drowsy by day, agitated at night. This diurnal fluctuation is characteristic of delirium.
- Inattention - she cannot recall three objects after one minute and is picking at her bedclothes, indicating impaired attention and altered awareness.
- Visual hallucinations ('people in the room') are common in delirium, particularly in the context of infection or metabolic disturbance.
- A clear premorbid baseline - she lived alone, managed her medication and finances, and walked daily. This argues strongly against a pre-existing dementia.
- A likely precipitant - fever 38.1 C, tachycardia 104, and SpO2 93% suggest an underlying physical cause such as infection (for example, a urinary or respiratory infection) or hypoxia.
Why the distinction matters: Delirium is a medical emergency with an identifiable cause and is potentially reversible. Dementia is a progressive cognitive decline. Mistaking delirium for dementia ('just old age') risks missing a treatable infection or hypoxia, which can lead to falls, injury, and death.
The fall may be both a consequence of the delirium and a cause of further injury; it should be assessed, not dismissed as the whole story.
2. What immediate actions and investigations would you undertake in the clinic, and how would you respond to the daughter's question about taking her home?
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Immediate actions:
- Do not send her home. She has an acute confusional state with fever, tachycardia, and borderline hypoxia, and is at high risk of further falls and injury. She needs urgent medical assessment, likely in hospital.
- Assess the fall: examine the left forearm for deformity, swelling, and neurovascular status, and arrange imaging if a fracture is suspected.
- Check oxygen saturation and give oxygen as per protocol if she remains below target; recheck after intervention.
- Assess for infection: check temperature trend, ask about urinary symptoms, cough, and bowel habit, and examine for sources.
- Check capillary glucose to exclude hypoglycemia as a cause of confusion.
- Review her medications for anything that could contribute (sedatives, anticholinergics, opioids).
- Arrange urgent referral to the emergency department or acute medical assessment, and communicate the findings clearly.
Investigations to anticipate: full blood count, CRP, urinalysis and culture, blood glucose, renal function and electrolytes, and chest imaging if respiratory signs are present.
Responding to the daughter: I would explain gently that this is not 'just old age' - it is a sudden change called delirium, which often has a physical cause such as an infection, and that it is treatable. I would explain that she is not safe to go home today because of the confusion and the fall risk, and that she needs to be assessed urgently. I would involve her in decisions and keep her informed, which also helps reduce her distress.
3. The daughter asks how to help prevent another episode. Outline the non-pharmacological measures you would teach and the safety advice for the home.
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Non-pharmacological measures to prevent and manage delirium:
- Orientation: keep a clock and calendar visible, use familiar objects, and gently reorient her to time and place.
- Routine: maintain regular day/night routines, with daylight exposure and reduced noise and light at night to support sleep.
- Hydration and nutrition: encourage regular drinks and meals, and watch for signs of dehydration or infection.
- Mobility: encourage safe walking with aids and supervision to maintain function and reduce falls.
- Sensory aids: ensure glasses and hearing aids are worn and in good repair.
- Medication review: have her medications reviewed regularly, especially sedatives and anticholinergics.
- Early recognition: teach the family that a sudden change in alertness or behaviour is a warning sign to seek medical advice promptly, rather than assuming it is dementia.
Home safety advice:
- Remove loose rugs and clutter, improve lighting, and use night lights.
- Install grab rails and ensure the bathroom is safe.
- Keep a phone within reach and consider a personal alarm.
- Ensure the daughter or a neighbour checks in regularly, and have a plan for what to do if she becomes confused again.
Reasoning principle: Delirium prevention is multifactorial. The most important teaching is that a sudden change in an older person is a medical warning sign, not an inevitable part of ageing.