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Acute Confusion

What is acute confusion in the elderly?

Acute confusion in the elderly is sudden and occurs in the space of hours to days. It is sometimes referred to as secondary dementia or delirium. It usually has a specific cause which has to be searched for and ruled out because once corrected, the patient tends to return to their normal self.

In medicine delirium is usually a symptom of acute illness but it has a definition of its own and its core features are:

1)    A disturbance of consciousness

2)    A change in cognition

3)    Rapid onset of hours to days

4)    Tendency to fluctuate

5)    Abnormalities of awareness and affect (e.g hallucinations or emotional lability)


Acute confusion is not associated with degenerative brain changes, which can be found on CT of the brain, and it is not chronic confusion, which tends to be due to old age dementia and in that spectrum the most common is Alzheimer’s disease.

Note that patients can have acute on chronic confusion, where their confusion state differs from their usual baseline level of confusion. Thus it is crucial to obtain a good collateral history from someone who knows the patient well.

Signs and Symptoms

This is variable and sometimes person specific but anything out of the ordinary in someone’s personality should raise suspicion. Things to look out for are:

-       Agitation (Hyperactive)

-       Drowsiness (Hypoactive)

-       Hallucinations (usually visual in delirium)

-       Nonsensical speech

-       Altered sleep pattern.

Please take into consideration and rule out sensory impairment, language barrier and ethnical differences when considering confusion states.

Causes of acute confusion in the elderly

Sudden confusion in the elderly has many causes

Using the Mnemonic VITAMIN C,D,E,F

V: Vascular – CVA, TIA, Vascular dementia

I: Infective/Inflammatory – Local or systemic infection e.g UTI, Chest infection, Infected ulcer, Sepsis

T: Trauma – Head injury, Intracranial haemorrhage,

A: Auto-immune – Thyroid dysfunction

M: Metabolic – Electrolyte disturbances, SIADH

I: Idiopathic/Iatrogenic – Medication e.g Opiates and Sedatives, Alcohol, recreational drugs

N: Neoplastic – SOL in the brain, Cancer

C: Congenital – Severe Cardiac myopathy, Hypertensive encephalopathy, Seizures

D: Degenerative/Developmental – Dementia, Learning disabilities, Depression

E: Endocrine/Environmental – Diabetes, Dehydration, Constipation, Nutritional deficits e.g Vitamin deficiencies, change of environment, sleep apnoea, hypo/hyperthermia

F: Functional – Sensory deficiencies e.g hearing problems, visual problems, language.


How to diagnose acute confusion in the elderly?


Good history is essential

1.  Previous cognitive function & health status

2.  Baseline functional ability (mobility, aids)

3.  Onset and course of confusion

4.  Previous episodes

6.  Signs/Symptoms of an underlying cause

7.  Social history

8.  Full drug history including non-prescribed drugs and alcohol intake.



- Full neurological exam (however this can be difficult in terms of compliance)

- Determine the consciousness level (AVPU, Glasgow Coma Scale)

- Full set of observations (Don’t forget temperature and blood sugar)

- Abbreviated Mental Test (AMT) and/or Mini Mental State Examination (MMSE)

- Use a confusion scale for example the Confusion Assessment Method (CAM) (see below for how to use this)



- Bloods: FBC, CRP, U+Es, LFTs, Glucose, TFT’s

- Urinalysis: Dipstick +/- MSU

- Chest X-ray


- CT head

- Others: ABG’s if appropriate, Haematinics if anaemia is found, Lumbar puncture (LP) if meningism is present



Treat the cause!

Avoid Sedation unless the patient is putting self or others at risk

Beware that in Parkinsonian patients and Lewy Body dementia Haloperidol is contraindicated.


Confusion Assessment Method (CAM)

Feature 1: Acute Onset and Fluctuating Course

Usually acquired information from a family member or nurse. Is there evidence of an acute change in mental status from the patient’s baseline? Does that behaviour fluctuate during the day?

Feature 2: Inattention

Does the patient have difficulty focusing their attention, being easily distractible, or having difficulty following the conversation?

Feature 3: Disorganized thinking

Was the patient’s thinking disorganized or incoherent, such as rambling or irrelevant conversation, unclear or illogical flow of ideas with a change from subject to subject?

Feature 4: Altered Level of consciousness

This feature is shown by any answer other than “alert” to the following question:

Overall, how would you rate this patient’s level of consciousness? (alert [normal]),  vigilant [hyperalert], lethargic [drowsy, easily aroused], stupor [difficult to arouse], or coma [unarousable])

The diagnosis of delirium by CAM requires the presence of features 1 and 2 and either 3 or 4 (or both).

In conclusion, here is schematic summary representation of management of acute confusion:





-       American Psychiatric Association: diagnostic and statistical manual of mental

and findings. Int Psychogeriatrics 1991; 3 (2):149-167

compendium, second edition

disorders, fourth edition, Washington, D.C., American psychiatric association, 1994

-       Gemert van L. and Schuurmans M.; The Neecham Confusion Scale and the Delirium Observation Screening Scale: Capacity to discriminate and ease of use in clinical practice; BMC Nurs. 2007; 6: 3.

-       Guidelines for the diagnosis and management of delirium in the Elderly, BGS

-       Levkoff S, Cleary P. Epidemiology of delirium: an overview of research issues

-       National Institute for Health and Clinical Excellence. Delirium: diagnosis, prevention and management. (Clinical guideline 103) 2010.

-       Rockwood K. Acute confusion in elderly medical patients. JAGS 1989;37:150-154





schematic summary representation of management of acute confusion

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