Delirium is a complex neuropsychiatric syndrome which is often under-recognised by nurses. Studies have shown that nurses do detect changes but these are not linked with an understanding or recognition of delirium.

This integrative literature review aims to explore barriers and enablers raised by nurses which impact on the timely recognition of delirium in older palliative care patients.

Methods
Studies from 1988-2014 were identified using an inclusion/exclusion criteria reporting on nursing assessment and recognition of delirium in older palliative care patients. ProQuest and Google Scholar were the databases used in addition to Medline/PubMed using the “delirium” filter from CareSearch.

Results
Three studies met the selection criteria. Similar results emerged despite the heterogeneity of the studies related to methods, design and patient population.

Conclusion
This integrative literature review has identified that nurses working in different healthcare settings, including palliative care, have similar views, practices and experiences related to barriers and enablers believed to impact assessment and recognition of delirium. However more studies are needed, in settings other than inpatient palliative settings, in a variety of countries and in older palliative patients.

Introduction
Delirium is the most common neuropsychiatric complication in advanced cancer (Briebart & Alici, 2011). It is characterised by:
• A. Disturbance in attention (that is a reduced ability to direct, focus, sustain and shift attention) and awareness (reduced orientation to the environment);
• B. The disturbance develops over a short period of time (usually hours to a few days), represents an acute change from baseline attention and awareness and tends to fluctuate in severity during the course of the day;
• C. An additional disturbance in cognition (eg. memory deficit, disorientation, language visuospatial ability, or perception);
• D. The disturbances in Criteria A and C are not better explained by a pre-existing, established or evolving neurocognitive disorder and do not occur in the context of a severely reduced level of arousal such as a coma; and
• E. There is evidence from the history, physical examination or laboratory findings that the disturbance is a direct physiological consequence of another medical condition, substance intoxication or withdrawal (ie. due to a drug of abuse or to a medication) or exposure to a toxin or is due to multiple aetiologies, (Diagnostic and Statistical Manual or Mental Disorders – DSM-5 European Delirium Association and American Delirium Society 2014).

Based on eight different screening and assessment tools, the incidence in palliative care inpatients, ranges from 3-45% (Hosie et al. 2012). Prevalence rates: 13.3-42.3% at admission, 26-62% during the lengthy of stay in hospital, increasing to 58.8-88% weeks to hours preceding death has been reported (Hosie et al. 2012).


What is known about nursing assessment?
As nurses provide 24 hour care at the bedside, they can be better utilised in the early recognition of delirium. However, all the evidence so far stresses nursing assessments have been based on rapid information assessments contributing to missed delirium incidences (Dahkle & Phinney, 2008, Agar et al. 2012). When directly comparing nurse clinical assessment with gold standard definitions, nurse recognition of delirium ranged from 26-83%, highlighting 17-74% missed delirium incidences (Steis & Fick, 2008).

Through rapid assessment, however, it has been proven that nurses detect change (Dahkle & Phinney, 2008, Agar et al. 2012), but these changes are not linked with delirium (Dahkle & Phinney, 2008, Agar et al. 2012, Hosie et al. 2014b). Nurses recognise that delirious patients are distressed, confused, that their behaviour is inappropriate and they need help (Steis & Fick, 2008).

Barriers to the comprehensive assessment of delirium
The literature has clearly highlighted that nurses have a poor knowledge of the Diagnostic Criteria for Delirium (DSM-5) included n the Diagnostic Statistical Manual of Mental Disorders (Hosie et al. 2014a, Agar et al. 2012).

Nursing assessment is based on behavioural and cognitive changes rather than monitoring for key symptoms (Dahkle & Phinney, 2008, Steis & Fick, 2008).

Signs and symptoms such as acute onset, fluctuations of symptoms, inattention, disorganised thinking, memory impairment, perceptual disturbances, psychomotor agitation/retardation and changes in circadian cycle and the hypoactive variant are not recognised (Agar et al, 2012).

Early detection of delirium particularly in the context of hypoactive delirium, which can easily be mistaken for either depression or profound fatigue with its characteristics psychomotor retardation, paucity of speech with or without prompting, lethargy and reduced awareness of surroundings, has been clearly shown in the literature as one of the four major predisposing factors for delirium in addition to age (80 years and older), visual impairment and dementia (Inouye et al.2001, Spiller & Keen 2006, Briebart & Alici 2011, Hosie et al. 2014b).

It has also been proven that the under-recognition by nurses increases the number of risk factors present. If patients have three or four of these, under-recognition by nurses increases by 20-fold (Inouye et al.2001, Steis & Fick, 2008).

Implications for nursing practice
Under-recognition leads to under-treatment and poor outcomes (Inouye 2006, Irwin et al. 2008). This is evidenced through longer institutionalisation at a greater cost to the healthcare system (Milisen et al. 2004), increased patient functional decline, greater risk of falls, increased risk of morbidity and risk of dementia, contributing to increased patient and carer anxiety and/or distress (Milisen et al. 2004, Agar et al. 2012, Mir et al. 2014).

Therefore the aim of this integrative literature review is to explore the barriers and enablers voiced by nurses that may potentially impact on the timely recognition of delirium in older palliative care patients.

Methods
The search was undertaken in June 2014. Articles published 1988-2014 were sought. Databases searched ProQuest and Google Scholar and the website CareSearch (www.caresearch.com.au) was also included as part of the search strategy.

Keywords, “delirium” and “nursing assessment” and “older patients” and “palliative care” formed the basis of the broader search underpinning nursing assessment related to the patient population in question. The Medical Subject Headings (MeSH) ‘confusion’ [MeSH Terms] AND ‘advanced care planning [MeSH Terms] OR ‘attitude to death’ [MeSH Terms] OR ‘bereavement’ [MeSH Terms] OR ‘terminal care’ [MeSH Terms] OR ‘hospices’ [MeSH Terms] OR ‘life support care [MeSH Terms] OR ‘palliative care’ [MeSH Terms] OR ‘terminally ill’ [MeSH Terms] OR ‘death’ [MeSH] were added.

Nine thousand and eighty-six papers were retrieved. To ensure quality articles reflected sound argument and methodology as well as objective evaluation by experts in the field, only peer-reviewed papers were included (Dixon 2001).

Papers written in languages other than English could not be found using the selected databases and website. After excluding articles not related to humans, 55 articles were retrieved from ProQuest. Subsequent to applying date limits in Google Scholar (1988-2014) 7640 articles were sourced.

Based on the inclusion criteria 24 papers from ProQuest and 37 from Google Scholar were relevant. CareSearch, with its predefined palliative care filters yielded 52 articles. These were the strongest evidence of all citations. In addition a reference list of ar5ticles/abstracts papers resulted in an overlap leaving 48 articles. After reading titles and abstracts 16 papers were related. Through using the two databases and the CareSearch website, a total of 77 articles met the general inclusion criteria. However, after reading each of these articles, while contributing to a greater understanding of delirium, 74 were not specifically related to a palliative population, exclusively to nursing, only focused on the phenomenology of delirium or delirium assessment tools with only three relevant papers remaining that the selection criteria (Table 1).



Analysis
The broader search revealed a large body of information related to delirium based on the most current empirical and theoretical literature. From these papers, a thematic analysis, consistent with an integrative review approach (Whitemore & Knafl, 2005) was conducted to categorise the many different aspects of delirium and implications for nursing clinical practice. Studies exploring nursing recognition and assessment, older patients and palliative care were included.

Three studies were found to capture the context, processes and pertinent subjective elements related to nurses, their assessments of delirium, incorporating barriers and enablers highlighting similarities across many areas of nursing including palliative care. (Hosie et al. 2014a, Hosie et al. 2014b, Agar et al. 2012).

Results
Setting and demographics
While Agar et al. (2012) did not define the number of sites, healthcare settings included: palliative care, aged care (geriatrics), aged care (geriatric) psychiatry and oncology. Hosie et al. (2014a) focused on 30 participants working in palliative care inpatient units (n=9) within acute or subacute hospitals and the third study (Hosie et al. 2014b) comprised of 30 participants from nine specialist palliative care inpatient services across three Australian states.

The two studies undertaken by Hosie et al. (2014) required participants to be registered or enrolled nurses, currently working in a clinical role in Australian specialist palliative care inpatient units with a minimum of three months palliative experience. In the study undertaken by Agar et al. (2012), all participants worked rostered shifts, including night duty, except those in aged care, who only worked days with reported experience in the clinical areas from six months to 37 years.

Study characteristics, design and focus
Hosie et al. (2014a) and Agar et al. (2012) focused on recognition assessment based on the DSM-5 and the DSM_IV-TR respectively. The latter study also addressed barriers and enablers impacting on delirium recognition and nursing assessment and how nurses managed delirium, which is outside the scope of this paper. Hosie et al. (2014b) focused on barriers and enablers of recognition of delirium palliative care patients.

Semi-structured interviews were used, in all three studies, to gain insight into nurses’ views regarding difficulties in recognising and assessing delirium across many areas of healthcare including palliative care. A grounded theory perspective was utilised by Agar and colleagues (2012) to better understand how palliative nurses may differ from nurses working in other areas. The remaining two studies utilised a critical incident technique in conjunction with using a vignette of a hypoactive patient to prompt their recollection of a similar incident.

Study quality
The study conducted by Agar et al. (2012) consisted of a heterogenous sample of participants in terms of experience and areas of nursing. In order to demonstrate the nurses’ views and practices that were rich in experience related to delirium, the sample size (n=40) needed to be considered in terms of quality related to validity and generalisability.

This also applied to the studies conducted by Hosie et al. (2014a and 2014b) with sample sizes of (n=30). Because these participants were self-selected, results may have represented nurses’ views who were most interested in palliative care and not representative of those who were less interested in palliative care and who may have responded with less curiosity.



Barriers and enablers
By comparing the three final studies, common views based on nurses’ knowledge, experience and practice emerged. There were categorised into barriers and enablers.

Poor knowledge of the Diagnostic Statistical Manual Criteria for delirium became evident in the interviews (Agar et al. 2012, Hosie et al. 2014a, Hosie et al. 2014b). In addition, nurses’ lacked awareness of the hypoactive variant, which contributed to missed incidence of delirium (Agar et al. 2012).

Limited knowledge of predisposing factors such as sensory impairment, dehydration, prior cognitive impairment   and precipitating factors such as hypoxia, infection and treatments such as narcotics, steroids, anticholinergic drugs antineoplastic agents were also noted (Inouye 2006, Agar et al. 2012). Witnessing the distress of patients and their loved ones and difficulty balancing competing interested of delirious patients with other patients equally in need of attention, particularly those at the end of life, was of deep concern, especially if a peaceful death was unable to be achieved (Agar et al. 2012).

In trying to balance challenging needs and heavy workloads, nurses believed support strategies from management were lacking (Steis & Fick 2008, Agar et al. 2012). Non-pharmacological interventions such as one-on-one nursing were suggested as potential enablers, as this was viewed as a valued support mechanism allowing nurses more time to clinically assess and address the complex care needs of delirious patients (Agar et al. 2012). Hosie et al. (2014s) highlighted that the participants also identified a gap in their own delirium knowledge. Strengthening collaborative multidisciplinary team relationships and a proactive communication based on trust between nurses, patients, family members and doctors were also recounted as potential enablers.

Concerns related to a lack of access to guidelines or integrating systems translating delirium knowledge into the workplace were raised. Admission delirium assessment, demonstrated to improve clinician recognition of delirium (Rao et al. 2011) were not in place, while nurses’ perception that cognitive and delirium assessments were lengthy and burdensome for palliative care patients were other barriers raised. To address this, a patient centred approach was suggested (Hosie et al. 2014b).

Further learning was embraced by all participants. In-services with a case study focus relevant to nursing and to the multidisciplinary team were proposed. Furthermore, debriefing was seen as beneficial ‘to break things down’ (Hosie et al. 2014b). Finally most participants believed a care plan or delirium ‘clinical pathway’ would provide a constructive method to assist in delirium screening assessment and management (Hosie et al. 2014b).

Discussion
This literature review has highlighted the paucity of high-quality evidence related to the barriers and enablers which impact early recognition of delirium, particularly in older patients, particularly in older patients who are receiving palliative care, despite age being one of the major independent risk factors which in under-recognised by nurses (Inouye et al. 2001). In the three studies found, 75% of the participants in one of the studies worked in areas other than palliative care (Agar et al. 2012).

This may have impacted the results, as the oncology nurses, who all possessed post graduate qualifications, demonstrated the greatest understanding related to oncological, medical precipitants, which may have limited comparability with the rest of the studies undertaken purely in palliative care settings.

Although the participants had wide experience in delirium and worked in diverse roles in a range of locations, essentially all the studies were undertaken in Australia and as such reflected views and experiences of Australian palliative care nurses. Furthermore, the data is based on the provision of palliative care in inpatient palliative care units. Therefore, the data may not be representative of nurses working in other settings such as community nursing and in other countries, where palliative care is still developing and where most cancers are diagnosed at late stages, which ultimately may impact on early recognition delirium by nurses (Crane 2010).

Conversely, two different methodologies were used, yielding similar results. This adds validity to the findings in terms of nursing possessing, an incomplete delirium knowledge and reliance on a non-formalised assessment approach to delirium recognition and assessment, rather than using a structured delirium screening and assessment, based on the Diagnostic Statistical Manual Criteria for Delirium (Dahkle &Phinney 2008, Steis & Fick 2008, Agar et al. 2012, Hosie et al. 2014a, Hosie et al. 2014b).

Conclusion
This integrative literature review has highlighted a dearth of evidence related to nursing assessment in the early recognition of delirium in older palliative care patients. However, from the scant information available, nurses working in a variety of healthcare areas, including palliative care, voice similar concerns related to barriers and enablers which are believed to impact timely recognition of delirium. More studies are needed in relation to nurses recognising delirium in older palliative patients, in settings other than inpatient palliative settings and countries other than Australia.

Implications for nursing practice
Gaps in clinical practice have been identified despite nurses being well placed to detect delirium and its fluctuating symptoms (Agar et al. 2012, Hosie et al. 2014a, Hosie et al. 2014b). This paper highlights more education and training is needed (Tabet & Howard 2006). An essential part of this learning is knowledge of the Diagnostic Criteria for Delirium in the Diagnostic Statistical Manual 5 (DSM-5) (Agar et al. 2012, American Psychiatric Association 2013, Hosie et al. 2014a, Hosie et al. 2014b) and a greater understanding of the predisposing risk factors (Inouye et al. 2001, Agar et al. 2012). In the clinical setting to further assist nurses in detection of early delirium, training is needed in the use of a validated delirium screening tool such as the Nursing Delirium Screening Scale (Nu-DESC), which still needs validation for use by nurses to assess palliative patients (Gaudreau et al. 2005a).

Clinical guidelines for the prevention, detection and management of delirium, in terms nurses can understand and engage (Delirium Clinical Guidelines Expert Working Group 2006, Steis & Fick 2008, National Institute for Health and Clinical Excellence (Nice 2010)) were also believed to enhance nursing assessment in the early recognition of delirium. However, it is vital that guidelines are not followed blindly and that nurses’ practice holistically, therefore consider the individual circumstances (Bush & Bruera 2009).

Implications for future research
More research is needed related to nursing assessment and recognition of delirium in the older patients in palliative care, including in settings other than inpatient palliative care units such as in community settings. More studies based in other countries are also needed to determine if the Australian experience reflected in other countries. Follow up studies are essential to trial proposed enablers in terms of interventions, including delirium education using contextual learning such as case studies and trialling an assessment/ screening tool such as the Nu-DESC administered by nurses to older palliative adults.

Conflict of Interest
The authors declared that there is no conflict of interest.

Author
Mary Bozzo - MPALCare, Flinders University, Registered Nurse, North Wing, University Hospital Geelong

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