Delirium in cancer care

Dr Kerry-Ann Louw expands on why a cancer patient may experience delirium, the causes, treatment and prevention thereof.

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Delirium is a syndrome of brain dysfunction which presents with sudden onset of disturbance of awareness, attention, and cognitive function. Delirium is the most common neuropsychiatric complication we see in patients with cancer. The prevalence rate of delirium is up to 30% on hospital admission and up to 85% in the terminal phase of illness.

Delirium is often missed because it has a fluctuating course and it can be misdiagnosed as dementia, depression, anxiety, or another psychiatric disorder. It’s important to diagnose and treat delirium. Delirium is associated with greater morbidity and mortality, longer hospital stays, long-term cognitive decline and distress in patients and their families.

Risk factors

Risk factors for developing delirium include advanced age, pre-existing dementia, brain disorders such as stroke, visual or hearing impairment, nutritional deficiencies, having multiple comorbid medical conditions and being on multiple medications.

Signs and symptoms

The signs and symptoms usually begin over a few hours or days, and they fluctuate throughout the day. Symptoms can get worse at night when it is dark. Delirium can last for a few hours or as long as weeks or months. The signs and symptoms include:

• Reduced alertness and awareness.
• Difficulty focusing on a topic, being easily distracted.
• Disorientation – not knowing where they are, what the date is or who they are.
• Cognitive disturbances: poor memory, difficulty speaking or understanding speech, incoherent speech, difficulty reading or writing.
• Increased motor activity: restlessness, agitation.
• Decreased motor activity: becoming more withdrawn.
• Mood fluctuations: depressed mood, euphoric mood, irritability, anxiety.
• Perceptual disturbances (hallucinations or illusions) or delusions.
• Disorganised thought processes.
• Disturbed sleep-wake patterns.

Three subtypes

There are three subtypes of delirium.

• The hyperactive subtype presents with increased motor activity, agitation, psychotic symptoms, hypervigilance, and inappropriate behaviour.
• The hypoactive subtype presents with reduced motor activity, lethargy, and reduced awareness of surroundings. This is often mistaken for depression.
• The mixed subtype presents with both hyperactive and hypoactive signs and symptoms.

Causes

Delirium may have a single cause but usually has multiple causes such as infection, dehydration, electrolyte disturbance, medication effects, pain, nutritional deficiency, organ failure and medical conditions such as stroke.

It’s a medical emergency and the most important first step is to identify and treat the underlying cause. If someone shows signs of delirium, they should see a doctor. The doctor will take a history and assess mental state and conduct a physical and neurological examination. Blood, urine, and radiological investigations may be requested. The assessment will help to identify the underlying causes and triggers for the delirium and will guide treatment choices. For example, medication may need to be changed, pain control improved, an electrolyte replaced, or an antibiotic given to treat an infection.

Further treatment

Environmental interventions are also important and include coordinated nursing care, preventing sensory deprivation, regular orientation, pain control, early mobilisation, promotion of good sleep patterns, monitoring of nutritional status and hydration.

Sedative and antipsychotic medications may be needed when there is agitation or psychosis, particularly if the person is putting themselves or others at risk. Antipsychotics are usually discontinued seven to 10 days after the symptoms have resolved. In the case of terminal delirium, the focus is on ensuring comfort and good end-of-life care.

Prevention

Delirium can be prevented by managing risk factors such as poor nutrition, hearing impairment and dehydration. Promoting good sleep patterns and regular orientation are also helpful. Medical problems and treatment side effects should be managed early on.

When recovering from delirium, it’s important to have good sleep habits, keep the environment calm with regular orientation and set routine, mobilise regularly, control pain, have adequate nutrition and hydration and manage medical problems appropriately.

Delirium can be a very frightening experience; patients, their families and caregivers may need emotional support following a delirious episode.

References

1. Breitbart W, Alici Y. Agitation and Delirium at the End of Life: “We Couldn’t Manage Him.” Jama. 2008;300(24):2898–910.
2. Taylor DM, Barnes TRE, Young AH. The Maudsley Prescribing Guidelines in Psychiatry. 2022;
3. Zyl LT van, Seitz DP. Delirium concisely: condition is associated with increased morbidity, mortality, and length of hospitalization. Geriatrics. 2006;61(3):18–21.
4. Association AP. Diagnostic and Statistical Manual of Mental Disorders, DSM-5-TR. 2022;
5. Potter J, George J, Group GD. The prevention, diagnosis and management of delirium in older people: concise guidelines. Clin Med. 2006;6(3):303–8.
6. Nayeem K, O’Keeffe ST. Delirium. Clin Med. 2003;3(5):412–5.
7. 7. Burns A, Gallagley A, Byrne J. Delirium. J Neurology Neurosurg Psychiatry. 2004;75(3):362.

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