Overview of delirium in palliative care

Delirium is an acute deterioration of mental state characterised by fluctuating symptoms of impaired attention, cognition and consciousness, typically developing over hours to days.

Delirium can be classified as:

  • hyperactive delirium with agitation, restlessness, hallucinations or delusions
  • hypoactive delirium with reduced activity, fatigue and withdrawal
  • mixed delirium with symptoms of both hyperactive and hypoactive states.

Delirium is associated with significant mortality and morbidity (eg falls), and can be distressing for patients, their families and carersAustralian Commission on Safety and Quality in Health Care (ACSQHC), 2021Finucane, 2017. Frequent recurrences of delirium indicate a poor prognosis and the need to review goals of care.

The prevalence of delirium is high in patients with palliative care needs; estimates vary from 4 to 12% in the community, and 6 to 74% in inpatient palliative care unitsWatt, 2021. Delirium becomes increasingly common as death approaches; up to 88% of patients in the last weeks of life experience itHosie, 2013Watt, 2019. Despite the high prevalence, delirium is frequently underdiagnosed. At the time of writing, no trials have been undertaken to determine whether screening for delirium improves outcomes in patients with palliative care needs, and many screening tools have not been validated in palliative care settingsWatt, 2021. Nevertheless, screening combined with evidence-based prevention strategies (see Preventing delirium in palliative care) is a pragmatic, reasonable approach1.

1 Australian healthcare services are required to undertake screening for cognitive impairment (a risk factor for delirium) in adults who are aged 65 years or older (45 years or older for Aboriginal and Torres Strait Islander peoples); cognitive assessment is also required for patients with known cognitive impairment or dementia, a previous episode of delirium, severe medical illness or a current hip fracture. For further information, see the Australian Commission on Safety and Quality in Health Care (ACSQHC) Delirium Clinical Care Standard.Return