Delirium

Delirium is a very damaging complication that is common in terminally ill cancer patients.  While delirium can be transient and potentially manageable, it often occurs in the last hours or days of life and is a terminal event.   In patients with advanced cancer, prospective research has reported the prevalence of delirium to be 28-42% on admission to a palliative care unit and longitudinal data has suggested rates as high as 80-90% in the days and weeks before death.  A smaller percentage of patients develop delirium earlier in the course of their illness. 

Delirium usually complicates and interferes with treatment of other aspects of the illness and makes assessment of pain and symptoms difficult.  Patients with delirium often stop eating and drinking, and stop taking important medications.  There is also the risk that patients may fall and injure themselves and this concern may result in the use of restraints. Most important, delirium is a common cause of distress for patients, families and health care providers, and can interfere with meaningful personal interactions with family, friends and the palliative care team.

For patients who are not at the terminal phase of their disease, failure to recognize and treat delirium can result in increased rates of morbidity and mortality.
Even in terminal cancer, it is important to diagnose and treat delirium as appropriate management can result in more effective palliative care.

CAUSES
Most Common Causes Of Delirium (Often Multifactorial):

• medications: opioids, psychotropic drugs, corticosteroids;
• drug withdrawal: benzodiazepines, opioids, alcohol;
• infections: respiratory or UTI, septicemia;
• nutritional deficiencies;
• brain mets;
• dehydration;
• hypoxia;
• metabolic: electrolyte disturbances, hepatic failure, hypercalcaemia.

ASSESSMENT
Delirium is associated with disordered attention and cognition, and disturbances in psychomotor behaviour (i.e. agitation, delusions, hallucinations, paranoia).
 
Common Signs and Symptoms of delirium:

• disorientation to time, place, and/or person;
• impaired attention;
• impaired memory;
• reduced awareness of environment;
• impaired abstract thinking and comprehension;
• anxiety, fear, irritability, agitation;
• illusions, hallucinations;
• transient delusions;
• psychomotor agitation or retardation;
• insomnia and nightmares.

There are two main types of delirium: 

1. Hypoactive Delirium: Characterized by confusion, somnolence, and decreased alertness.  Most commonly seen in hepatic insufficiency, acute intoxication and hypoxia.
2. Hyperactive Delirium: Characterized by confusion, somnolence, and decreased alertness AND agitation, hallucinations, myoclonus, and hyperalgesia.  Often seen with cerebral metastases and substance withdrawal.

Delirium usually presents with sudden onset and a fluctuating course.  Delirium should be distinguished from dementia.  While both are disorders of cognition, delirium has a more significant alteration in arousal and attention.  Further dementia is chronic and has a gradual onset, and patients with dementia are usually have no disturbances in consciousness and are alert.

Unfortunately, though delirium is very common, up to 1/4 of episodes of delirium go unrecognized and untreated. For all palliative patients it is important to maintain a high index of suspicion of delirium. Close clinical observation of patients can play a key role in the detection of subtle symptoms that may indicate the onset of delirium (bedside nurses can play a key role in detection).

Health Care Providers (HCPs) should routinely assess for delirium and should ask the patient specifically about hallucinations (usually visual and tactile) and assess for paranoid ideation. Screening tools such as the Mini-Mental State Examination (MMSE) and the Confusion Rating Scale can be used to assess for signs of delirium.

When delirium is identified or suspected the physician should look for clinical signs of infection, opioid toxicity (myoclonus, hyperalgesia), dehydration, uremia, hepatic encephalopathy, etc. and order appropriate tests (i.e.  bloodwork, cultures and radiological exams).

MANAGEMENT
While delirium is generally an expected end-of-life occurrence, up to 45% of episodes (especially those occurring in the pre-terminal phase) are reversible.

Unless it is very clear that death is imminent or the cause of delirium is irreversible (i.e. significant hepatic encephalopathy), delirium generally should be approached as a reversible episode. The management of delirium should be on a "case-by-case" basis.

The first step in the management of delirium is to try and identify a cause for the delirium: 

• it is important to rule out any treatable medical causes of confusion (i.e. dehydration, hypercalcemia, sepsis, hypoxia) before prescribing medication (which may exacerbate confusion);
• discontinue any drugs that would be aggravating the delirium (i.e. Tricyclic antidepressants, benzodiazepines, and corticosteroids). Healthcare providers often misinterpret the agitation associated with delirium as anxiety and fear.  Treatment with benzodiazepines (lorazepam) for agitation may lead to a vicious cycle of escalating doses that exacerbates the underlying delirium;
• in the case that opioid toxicity is suspected, change the type of opioid to a 30% lower equianalgesic dose.

Non-Pharmacological Interventions
Delirium can be very distressing to both the patient and family, so it is important to provide education and general support for both the patient and the family.   Try to provide a calm and non-stimulating environment.  Always use a gentle, calm and re-assuring approach and explain all procedures even if the patient does not seem to understand.

It is important to ensure the safety of the patient as well as the family and HCPs.  In some cases, the use of restraints is necessary.  Using restraints will require additional education for the caregivers and more frequent assessment of the patient's skin condition.  Physical restraints may cause more agitation and confusion and should be used judiciously.

If the patient is close to death, it is important to tell the family that delirium is a sign of approaching death.

Pharmacological Interventions

Haloperidol 

• Drug of choice for treatment of hyperactive delirium.
• It is appropriate to bring an agitated delirium under control rapidly to prevent patient, family and staff distress.

Methotrimeprazine

• If there is no response within 36-48 hours despite Haloperidol use, Methotrimeprazine can be used.
• This drug can be sedating.

Midazolam

• In rare cases, sedation for uncontrolled agitation using Midazolam is required. 
  

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This page was last updated: March 8th, 2005 at 6:02pm.