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Delirium in advanced disease, while common, is often not recognised or poorly treated. The aim of management of delirium is to assess and treat reversible causes in combination with environmental, psychological and pharmacological intervention to control symptoms. Delirium presents significant distress and impedes communication between patients and their families at the end of life. A structured approach to recognise, assess and manage delirium is essential for all clinicians caring for patients with terminal illness.
Patients at the end of life develop a number of distressing symptoms. Although delirium is one of the most common neuropsychiatric problems in patients with advanced cancer, it is poorly recognised and poorly treated.1
Delirium is prevalent at the end of life, particularly during the final 24–48 h. Prospective data suggest a prevalence of delirium of 28–42% on admission to a palliative care unit and longitudinal studies have documented occurrence rates as high as 88% before death.1,2,3,4,5 All patients at the end of life can therefore be considered at high risk of delirium.
Delirium presents significant problems: distress for the patient, anxiety and distress for family, and management challenges for health care workers. Delirium interferes dramatically with the identification and control of other physical and psychological symptoms, impedes the ability to make final choices and plans, and for some patients will be a marker of approaching death. Prompt recognition and appropriate treatment of delirium can improve patient comfort and optimise quality of life.3
Delirium is characterised by rapidly emerging disturbance of consciousness and a change in cognition with fluctuating symptoms and evidence of organic aetiology.
The pathogenesis of delirium is complex and poorly understood: abnormalities of several neurotransmitters and endogenous agents have been postulated (including reduced cholinergic transmission, altered γ aminobutyric acid transmission, altered serotonin transmission, cytokine production and altered cortisol levels).6,7,8
If vulnerability at baseline is high then delirium is likely to occur with exposure to relatively minor precipitating factors.10,11 Delirium may be a marker of the terminal phase of illness and 10–23% of patients in palliative care units require terminal sedation because of delirium.2 Delirium at this stage is not usually reversible (due to the fact that irreversible processes such as multi‐organ failure are occurring).9
When assessing the patient, particular attention should be paid to the medication history: several drugs commonly used in the palliative care setting may precipitate delirium (for example, opiates, steroids and benzodiazepines), particularly in older patients. Recent drug cessation (for example, benzodiazepines) and usual alcohol intake are also important.
A history from a relative or carer regarding the onset and course of confusion and baseline level of cognitive function is also vital.
Examination may reveal signs of precipitating factors—for example, pneumonia, acute alcohol withdrawal or urinary retention.
The decision to proceed to further investigations should take into consideration the stage of disease and likelihood that a reversible cause will be found; metabolic causes of delirium may occur in up to 18% of terminally ill patients with cancer.3 A targeted assessment may include: renal function, calcium, glucose, liver function, full blood count, thyroid function and B12, adrenal function, urine/blood culture, chest x ray, computed tomographic scan of head, and cerebrospinal fluid examination.3,13
While there are established diagnostic criteria for delirium (table 22),), it is frequently under‐recognised and mistreated; up to half of delirium episodes are not noted by clinicians.1,2,3 It is important to appreciate that delirium may present as one of three subtypes:3,4,12,13
Diagnosing delirium and distinguishing it from other conditions can be problematic. For example, the hypoactive subtype may be misdiagnosed as depression due to misinterpretation of slowed psychomotor function, lethargy and reduced awareness/interaction with the environment.4,6 While the Mini Mental State Examination (MMSE) is able to identify patients with cognitive problems it does not distinguish delirium from other diagnoses (both dementia and depressed patients (with “pseudo dementia”) may have low scores on an MMSE).16
A number of other tools have therefore been developed to distinguish delirium from other causes of altered mental status (for example, Delirium Rating Scale (DRS) and Memorial Delirium Assessment Scale (MDAS)) although these are infrequently used in clinical practice.4,15,17 The Confusion Assessment Method (table 22)) is a simple tool to diagnose delirium which has a high sensitivity and specificity and has been validated for use in the palliative care setting.4,11,12,15
Detection of delirium can be improved putting greater emphasis on routine cognitive testing and the use of screening instruments.11
The most important action for the management of delirium is the identification and treatment of the underlying reversible causes (table 11).). Delirium may be reversible in up to 50% of patients with advanced cancer, particularly where the precipitant is opiates or other psychoactive medication or metabolic disturbance (for example, dehydration or hypercalcaemia).1,2 While delirium may have a single cause, a multifactorial aetiology is most commonly found in the palliative care setting.3
Of all patients with delirium, medication may be implicated in 12–40% of cases.7,8,11 Observational studies have shown that the most common drugs associated with delirium are sedative hypnotics (for example, benzodiazepines), analgesics (for example, narcotics) and medication with an anticholingeric effect.8 Polypharmacy is itself a risk factor for delirium.8
A review of all medication is therefore fundamental, with particular attention being paid to any temporal relationship with delirium onset and recent additions or drug dose changes.8
Further management incorporates pharmacological and non‐pharmacological measures to reduce the symptoms and prevent complications—for example, falls (table 33).
Non‐pharmacological strategies for management are free of adverse effects but are underutilised.11 In general non‐pharmacological measures should be used first and then pharmacological agents if unsuccessful (sedation may be required in 9–26% of patients with delirium at the end of life3).
The use of ward transfers, physical restraints, anticholinergic drugs and catheters should be avoided where possible. Cot sides have not been shown to reduce the risk of falls and may increase the risk of injury.12
If required, the aim of drug treatment is to reduce distressing or dangerous behavioural disturbance (for example, agitation and hallucinations). Use only one drug if possible, haloperidol being currently recommended as first line (although evidence to form the basis of guidelines on drug treatment for delirium in terminally ill patients is very limited).11,18 Notable exceptions are alcohol withdrawal and Lewy body dementia where a benzodiazepine is more preferable; in other patients with delirium benzodiazepines can paradoxically worsen the confusion if used alone.2,4,12,18
Delirium in the last few days of life (often referred to as terminal restlessness or terminal agitation) is often ongoing and irreversible. Evidence suggests that delirium in cancer patients with terminal disease may require more than a single drug treatment, and 10–20% of terminally ill patients experience delirium that can be controlled only by sedation to significantly decreased levels of consciousness.13,19
Explanation and discussion with family is essential.
Issues of capacity and informed consent will arise in relation to the treatment of delirium. Interventions needed to prevent serious deterioration or death, or which are necessary in the interests of patient safety, are covered by common law in the UK.5 The new Mental Capacity Act 2005 endorses the principle of clinicians acting in “best interests” and is a statutory codification of the existing common law position.20
There are other important implications of the Act (which will become law in April 2007), particularly the presumption that all patients have capacity unless it is proven to the contrary: an adult can be deemed to have capacity to consent or refuse treatment if they: (a) understand the information relevant to the decision; (b) retain the information relevant to the decision; (c) use or weigh the information; and (d) communicate the decision (by any means).20
The Act also provides statutory clarification of the role of advance decision making but restricts this to advance decisions to refuse treatment stipulated for particular situations. Broader “advance directives” and “living wills” will have relevance when deciding “best interests” but are not legally binding.5
Finally, the current provision of appointing an Enduring Power of Attorney relates only to property and affairs; however, Lasting Powers of Attorney appointed under the new Act will have power to make health care decisions on behalf of the incapacitated person (this does not extend to refusing life‐sustaining treatment unless this is explicitly stated).5
Delirium is common in advanced disease and has a significant detrimental effect on quality of life for patients and their families. Patients with advanced disease are at high risk of developing delirium, particularly those with multiple predisposing and precipitating risk factors. Clinicians should be vigilant in order to recognise delirium when it occurs and use a structured approach to assess and manage the patient.
Management of delirium in the terminally ill involves treatment of the underlying cause if possible (and eliminating non‐essential drugs which may be contributing), environmental strategies, and the use of medication to control symptoms and behaviour.
DRS - Delirium Rating Scale
MDAS - Memorial Delirium Assessment Scale
MMSE - Mini Mental State Examination
1. (A) F: delirium is common in advanced disease; (B) T; (C) F: up to 50%; (D) F: usually multifactorial; (E) F: all may have low MMSE scores
2. (A) F (B) T (C) T (D) F (E) F
Conflict of interest: None