Lionel Thorpe, 79 years old was brought in by ambulance from the nearby nursing home. He is confused and agitated and has been lashing out at the nursing staff who are trying to change the dressing on his leg ulcer. He claims that they are trying to poison him.
On arrival he is alert and shouting abuse at the ambulance officers. Once he is reassured that he is no longer at the nursing home, he calms down enough for you to talk to him. However he is confused and disoriented and unable to provide any history details.
History and examination, including mental status questionnaire, are vital parts of the investigation of an acutely confused patient. History may need to be taken collaboratively from the patients, family, carers, hostel staff etc.
History must include:
Delirium is an impairment of cognitive function that is not progressive, but is reversible. The impairment of consciousness varies, often being worse at night. It may be described as a transient organic brain syndrome characterized by concurrent disorders of attention, perception, thinking, memory, psychomotor behaviour and the sleep-waking cycle.
An aide-memoire for the common causes of delirium is HIDEMAP:
A top to toe examination is required, starting with a mental state examination to determine the severity of the delirium. Delirium is characterised by:
One method, the Confusion Assessment Method, identifies delirium as the presence of the above features (1) and (2) and either (3) or (4).
Clinical features of delirium include:
Dementia v Delirium - Key Differences:
| Dementia | Delirium | |
|---|---|---|
| Mode of onset | Sub acute | Acute |
| Poor attention | Late event | Characteristic |
| Conscious level | Normal | May be wild fluctuations |
| Hallucinations | Late event | Common |
| Agitation/Aggression | Uncommon until late | Common |
| Thought form | Usually poverty of thought in late dementia | Flight of ideas |
| Memory | Normal until late | Poor |
He has a vascular dementia, so progression via CVA or other vascular event (e.g. AMI, DVT and PE), moving room, sleep disturbance, new medications, infections would be first things to be ruled out.
As above, the differential diagnosis for the more common causes of delirium include:
Other causes include cerebrovascular events and malignancies.
Emergency investigations are essential in all patients:
The following investigations are useful in many patients:
Second line investigations depending on the indication:
Management strategy options:
Patients with severe delirium should never be left alone or unattended.
Environmental modifications
Physical restraint
Physical restraints should be avoided. Delirious patients may pull out intravenous lines, climb out of bed, and may not be compliant. Perceptual problems lead to agitation, fear, combative behaviour, and wandering. Severely delirious patients benefit from constant observation (sitters), which may be cost effective for these patients and help avoid the use of physical restraints.
Medication
Delirium that risks causing injury to the patient or others should be treated with medication.
Neuroleptics (or antipsychotic drugs) are the medication of choice. Older neuroleptics, such as haloperidol, are useful but have many adverse neurological effects. Newer neuroleptics such as risperidone, olanzapine, and quetiapine relieve symptoms while minimizing adverse effects. Initial doses may need to be higher than maintenance doses. Use lower doses in patients who are elderly.
These medications should be discontinued as soon as possible. Attempt a trial of tapering off the medication once symptoms are in control.
Neuroleptics can be associated with adverse neurological effects such as extrapyramidal symptoms, neuroleptic malignant syndrome, and tardive dyskinesia, particularly in elderly patients.
Doses should be kept as low as possible to minimize adverse effects. Paradoxical and hypersensitivity reactions may occur.
Benzodiazepines are the treatment of choice for alcohol withdrawal delirium.