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Delirium in palliative medicine |
This article is based on a lecture given by Dr William Brietbart, Department of Psychiatry and Behavioural Sciences, Memorial Sloane-Kettering Cancer Centre, New York at the Australian and New Zealand Society of Palliative Medicine Conference, September 8, 2000.
Delirium is a common occurrence in the palliative care setting and increases in prevalence with disease progression. It can occur in 40-85% of patients in the last weeks of life and in that respect can be viewed as a harbinger of death. It is associated with increased morbidity/distress in patients, families, and staff. It interferes with symptom assessment and control.
In one study, 50% of patients remembered being delirious and it caused them extreme distress (self-rating as 8.5/10). The 50% of patients who did not recall being delirious however also rated their distress high because they could not remember and were fearful of what they may have done or said. The family rated their distress at seeing their loved one delirious as 9.5/10, staff rated their own distress 9/10. Contrary to expected findings, patients who had been quietly delirious were just as distressed as those who were extremely agitated.
Despite being a common symptom, the clinical features can often be quite subtle and can easily go unrecognised and untreated.
- Altered conscious state
- Altered mood (excited or depressed)
- Impaired short term memory
- Impaired thinking (delusions)
- Impaired judgement
- Altered perceptions (hallucinations, illusions)
- Disorientation (time, person, place)
- Disordered speech
- Disturbed sleep pattern (drowsy by day, insomnia at night)
- Abnormal psychomotor activity (increased or decreased)
It can be quite difficult at times to distinguish dementia from delirium but the main features of delirium are:
- global impairment,
- subacute/acute onset,
- fluctuation of symptoms during the day.
The DSM IV criteria further distinguishes delirium as:
A. Disturbance of consciousness, ie. disturbance of awareness of the environment with reduced ability to focus, sustain or shift attention.
B. Change in cognition (such as memory deficit, disorientation, language disturbance, and perceptual disturbance) that is better accounted for by a pre-existing, established or evolving dementia.
C. Disturbance evolves over a short period and fluctuates during the course of the day.
D. There is evidence from the history, examination and laboratory findings of a general medical condition judged to be aetiologically related to the disturbance (ie. can be multiple small biomedical disturbances).
- Primary brain tumour
- Metastatic spread
- Hypoxia
- Metabolic encephalopathy due to organ failure (remember hypercalcaemia)
- Electrolyte imbalance
- Withdrawal states (alcohol, opioids, benzodiazepines, nicotine)
- Drugs (steroids, opioids, anticholinergics, antiemetics, anxiolytics, antidepressants, anticonvulsants, NSAIDs are the most common)
- Sepsis (UTI, chest)
- Nutritional deficiencies (Werneke’s encephalopathy)
- DIC, bleeding (subdural haematoma)
- Paraneoplastic syndromes
- Endocrine disorders
- Constipation
- Urinary retention
- Pain
1. Reverse the reversible
Reversible causes of delirium include:
- Pain (impaction or retention?)
- Drugs
- Infection
- Dehydration
- Withdrawal states
- Hypercalcaemia
Most often the aetiology of terminal delirium is multifactorial or not found. When a distinct cause is found, it is often irreversible, eg. hypoxic encephalopathy and metabolic causes are associated with irreversibility.
Even if a nonreversible cause is discovered, it may help to know the reason for confusion and avoid further invasive investigation.
Whatever the scenario, the diagnostic work-up must be consistent with goals of care and the focus should remain on relieving patient distress.
2. Non-pharmacological interventions
a. Ensure safety of patient, family and staff.
b. Reassure family and patient of the medical nature of delirium, ie. “Not losing your mind” or “having a nervous breakdown”.
c. If this is end-stage disease, it may be necessary to tell the family that delirium is a hallmark of approaching death.
d. Providing clocks, dates, time etc to re-orientate the patient have not been found to be helpful, although they may delay the onset of delirium.
e. Communicate with the patient and the family. What are the goals of care and desirable outcomes? Eg sedation versus being alert but distressed.
3. Pharmacological interventions
1st line - Haloperidol
- 0.5 – 5mg q2- 12hr
- Usually given orally or subcutaneously, (parenteral doses are twice as potent as oral doses).
- Usual maximum oral daily dose 10mg. If higher doses are needed, specialist advice is recommended.
- Haloperidol is not a sedative and if sedation is required, alprazolam or lorazepam 0.5-1mg q2hr prn is a useful addition.
2nd line - Chlorpromazine
- 12.5 – 50mg q4-12hr
- Usually given orally or rectally (100mg rectally = 50mg orally)
- Usual maximum daily dose 200mg
- Chlorpromazine is more sedating than haloperidol.
Both haloperidol and chlorpromazine potentially lower the convulsant threshold and should therefore be avoided or used with caution where fitting is a possibility.
An alternative would be risperidone or olanzapine in these circumstances.
- Urinary retention and constipation are readily reversible and should not be missed as a cause of delirium.
- Sedation will not reverse confusion and will potentially exacerbate it; the correct management as outlined will greatly reduce the distress to both patient and family.
- Confusion is one of the most difficult symptoms to manage at home and admission should always be considered.
- Patients often have insight and it should gently be “re-orientated” in conversation if possible.
- Beware the quietly withdrawn patient – they may be quietly confused. (There is a common misdiagnosis of withdrawn delirium for depression).
- Beware the quietly confused patient – their distress is just as severe as the agitated patient.
References
P Lawlor et al, Archives of Internal Medicine, 2000
Breitbart et al , Am J Psy 1996
Breura et al, Psycosocial Aspects of Cancer, 1990
Oxford Textbook Palliative Medicine, 2nd Ed, 1998.
Dr Joanne Doran is the area medical director of palliative care for the Northern Rivers Area Health Service, Lismore, NSW, Australia.
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