Between a quarter and two-thirds of adults admitted to specialist palliative care units experience delirium, or acute confusion.
The findings come from a mixed methods project which included a systematic review of the number of people living with delirium. Estimates are mostly applicable to older adults with advanced cancer.
The project also included interviews with nurses in Australian palliative care units to look at delirium assessment and use of screening tools. The findings highlighted that systems which formally diagnose delirium were not commonly used. Delirium guidelines made little reference to palliative care.
The qualitative findings may also have relevance to the UK, though systems will differ. They suggest a need for education and training about delirium among palliative care practitioners.
The implementation of hospital-based screening and assessment tools in specialist palliative care units might help with this, where recognition is poor.
Why was this study needed?
Delirium can involve confusion, disorientation, altered consciousness, withdrawal and sleepiness (hypoactivity), or restlessness and agitation (hyperactivity). It is common among older adults, those with severe illness, dementia or other cognitive impairments, affecting up to a third of people on medical wards, up to half on surgical, and around a fifth in long-term care.
The hospice sector cares for over 200,000 people each year, around half of those with terminal and life-limiting conditions in the UK. In terminal illness, delirium affects many people in their final weeks. Recognition and reporting of delirium are poor, assessment is difficult, and it may be mistaken for dementia, depression or fatigue.
This mixed methods project aimed to investigate the epidemiology of delirium and its recognition and assessment in palliative care units.
What did this study do?
The first phase of the Delirium in Palliative Care Project (DePAC) involved a systematic review of studies reporting delirium prevalence among adults admitted to palliative care units.
The eight studies identified included a large proportion (99%) of people with advanced cancer. Two studies were from the UK, two the US, and others from Canada, Japan, Hong Kong and Taiwan. All were published between 1996 and 2008. The studies varied in sample size, how they defined end-of-life, the tools used to assess delirium, and frequency of assessment. No studies met all quality criteria.
The second phase involved interviews with nurses in palliative care units in Australia to explore their recognition and assessment of delirium, and to assess the feasibility of a brief screening tool (the Nursing Delirium Screening Scale, NuDESC). It also included a scan to look at the uptake of guideline recommendations.
What did it find?
- In the systematic review, delirium prevalence on admission to palliative care units was reported at between 13% and 42% (five studies). Between 26% and 62% were reported to have delirium during their stay (four studies). Hypoactive delirium was the most common subtype, accounting for 68% to 86% of cases (three studies).
- Two studies gave limited evidence that delirium prevalence was higher among adults nearing the end of life. One study reported 59% prevalence for adults who died during admission. The other reported 88% prevalence among adults in the last six hours of life.
- Studies reporting at least daily screening reported a higher incidence of delirium (33-45%) than those reporting less frequent screening (3-7%).
- The qualitative study, conducted in Australia, found that delirium guidelines gave little mention of palliative care and those available were mostly consensus-based. There were no routine systems in place for recognition and assessment of delirium in Australian units, and patients and families were rarely involved or consulted. Nurses typically aimed to relieve distress without performing a comprehensive assessment. This highlighted the need for point-of-care tools. Trialling of the Nursing Delirium Screening Scale, followed by physician diagnosis using DSM-V, indicated this as a feasible and acceptable tool.
What does current guidance say on this issue?
The NICE guideline (2010) and quality standard (2014) on delirium do not cover end-of-life or palliative care.
NICE guidelines on the care of adults in the last days of life (2015) recommend considering non-pharmacological management of delirium and exploring possible reversible causes. Antipsychotics may be considered but may cause unwanted sedation.
Scottish palliative care guidelines (2014) outline the assessment and management of delirium. They state that careful clinical assessment is key to diagnosis, and suggest the Mini-Mental State Examination or Confusion Assessment Method as possible screening tools.
What are the implications?
The prevalence of delirium among adults receiving palliative care appears similar to that among hospitalised adults with acute illness.
The qualitative study indicated that delirium is under-recognised in Australian palliative care units and this may be true in the UK too. The global studies also suggested a similar problem. These highlighted a lack of formal assessment and variation in tools used which may have accounted for variation in prevalence estimates.
Recognition and assessment of delirium by health professionals working in palliative care seem essential to support effective prevention and management. If the tools for screening and assessment in hospital were used in palliative care, delirium might be better managed.
Citation and Funding
Hosie A, Agar M, Lobb E et al. Improving delirium recognition and assessment for people receiving inpatient palliative care: a mixed methods meta-synthesis. Int J Nurs Stud. 2017;75:123-9.
The project was funded through a Postgraduate Award by the Commonwealth Government of Australia.
Candy B, Jackson K, Jones L et al. Drug therapy for delirium in terminally ill adult patients. Cochrane Database Syst Rev. 2012;(11):CD004770.
Hosie A, Davidson P, Agar M, Sanderson C, Phillips J. Delirium prevalence, incidence, and implications for screening in specialist palliative care inpatient settings: a systematic review. Palliat Med. 2013;27(6):486-98.
Hosie A, Lobb E, Agar M, Davidson P et al. Measuring delirium point-prevalence in two Australian palliative care inpatient units. Int J Palliat Nurs. 2016;22(1):13-21.
Hospice UK. Hospice care: facts and figures. London: Hospice UK; 2018.
NHS Scotland. Scottish palliative care guidelines: delirium. 2014; updated 2016.
NHS website. Sudden confusion (delirium). London: Department of Health and Social Care; 2018.
NICE. Delirium prevention, diagnosis and management. CG103. London: National Institute for Health and Care Excellence; 2010.
NICE. Care of dying adults in the last days of life. NG31. London: National Institute for Health and Care Excellence; 2015.
Produced by the University of Southampton and Bazian on behalf of NIHR through the NIHR Dissemination Centre