Health Sciences Center Library, Kuwait University

Acute confusion

Delirium (a.k.a. Acute Confusional State) is an organic mental syndrome characterised by acute onset and fluctuating course. It occurs in the context of physical illness. Its duration is brief and the prognosis (either death or recovery) depends on the underlying physical condition.

Epidemiology.

10-20% of hospital inpatients,in general wards, manifest some degree of delirium.
Elderly people seem particularly likely to develop confusion in response to a wide range of stimuli - either physical insults or sudden social change. This presumably reflects the reduced ability of the aged brain to cope with such events, particularly if it is additionally damaged by a dementing process. An acute confusional episode may sometimes be the first evidence of an underlying dementia

Clinical Features.

The cardinal feature is impaired consciousness. This may manifest as impaired or fluctuating attention.
Disorientation (time, place and person)
New Learning impaired.
Disorganised thinking. Conversation may be rambling or incoherent.
Perceptual disturbances are frequent misinterpretations, illusions and hallucinations. (Benign stimuli may be misinterpreted as threatening).
Diurnal fluctuation.
Sleep wake cycle disturbed.
EEG shows diffuse slow wave activity.
In elderly people apathy, under-activity and clouding of consciousness are more common presentations of delirium, than the florid, overactive restless, hallucinating states usually described in relation to younger patients.
Acute confusion should be regarded as indicative of underlying disease and investigated medically. Untreated it has a 40% mortality rate.

Aetiology.

High risk groups include the very young and the elderly, individuals with pre-existing organic brain disease (e.g. dementia), alcohol and drug abusers.
Cause is usually multifactorial e.g. in postoperative delirium such factors as patients age, the stress of surgery, pain, insomnia, medication, electrolyte imbalance, fever, infection and the dim ward lighting, may all be contributory.

Intracranial causes include :

Epilepsy and post ictal states
Brain tumour
Infection
Haemorrhage.

Extracranial causes include:

Drugs (medical and recreational).
Endocrine dysfunction.
Disease of non-endocrine organs e.g. heart, liver, kidney or respiratory failure.
Deficiency states e.g. thiamine deficiency.
Electrolyte imbalance.
Withdrawal states - e.g. delirium tremens.
Operations, e.g. (black patch delirium following eye operations).
Catastrophic social situations, e.g. move into residential care

Assessment.

A full physical assessment mandatory.
Sometimes it is difficult to distinguish delirium from dementia but if in doubt assume it is delirium so that an immediate and vigorous therapeutic response is ensured.

Treatment.

Identify and treat cause.
Nursing care. Provide reassurance and explanation. If sensory deprivation is a factor improve lighting conditions.
A neuroleptic such as haloperidol may calm an agitated, restless patient and benzodiazepines are useful in the treatment of some withdrawal syndromes.

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