Delirium and the functional recovery of older medical inpatients after acute illness: The significance of biological factors

Consistent patterns in the inconsistent associations of Insulin-like growth factor 1 (IGF-1), C-Reactive Protein (C-RP) and Interleukin 6 (IL-6) levels with delirium in surgical populations. A systematic review and meta-analysis

BACKGROUND

Biomarkers for delirium could increase diagnostic accuracy and may help to identify pathological pathways. Until now study findings concerning cytokine levels have been inconsistent.

AIMS

Systematic review and meta-analysis investigating the association between peripheral levels of Insulin-like Growth Factor-1 (IGF-1), C-Reactive Protein (C-RP) and Interleukin-6 (IL-6) and delirium in surgical patients, and to explore if there are distinct/specific patterns that may potentially explain inconsistent results.

METHODS

PubMed, Scopus, CINAHL, Cochrane, and EMBASE databases were searched. Inclusion criteria were: prospective studies, surgical populations excluding preoperative delirium, available data. The following were collected: type of operation (orthopaedic, abdominal, etc), the timing of operation (acute, elective, both), demographics, number of participants with delirium, time of preoperative blood withdrawal, and preoperative levels of each biomarker.

RESULTS

Low levels of IGF-1 (n = 7 studies) are significantly associated with post-operative delirium in abdominal surgical samples. High levels of C-RP (n = 9) are associated with delirium in acute orthopaedic and elective abdominal operations. IL-6 (n = 14) is a significant predictor of post-operative delirium in a variety of surgical conditions (elective or acute).

DISCUSSION

A common pattern exists in the otherwise conflicting reported findings. This similarity may reflect different underling mechanisms and predisposing factors like cachexia and catabolic stages. It seems that delirium in abdominal surgery is triggered by IGF-1 disturbances, while in other surgeries by an inflammatory reaction.

CONCLUSIONS

Despite the contradictory results concerning the association of IGF-1, C-RP and IL-6 with postoperative delirium, the present meta-analysis shows that there are certain patterns. IL-6 seems a consistent predictor for delirium in surgical samples.

Understanding health-care outcomes of older people with cognitive impairment and/or dementia admitted to hospital: a mixed-methods study

Background

Cognitive impairment is common in older people admitted to hospital, but previous research has focused on single conditions.

Objective

This project sits in phase 0/1 of the Medical Research Council Framework for the Development and Evaluation of Complex Interventions. It aims to develop an understanding of current health-care outcomes. This will be used in the future development of a multidomain intervention for people with confusion (dementia and cognitive impairment) in general hospitals. The research was conducted from January 2015 to June 2018 and used data from people admitted between 2012 and 2013.

Design

For the review of outcomes, the systematic review identified peer-reviewed quantitative epidemiology measuring prevalence and associations with outcomes. Screening for duplication and relevance was followed by full-text review, quality assessment and a narrative review (141 papers). A survey sought opinion on the key outcomes for people with dementia and/or confusion and their carers in the acute hospital (n = 78). For the analysis of outcomes including cost, the prospective cohort study was in a medical admissions unit in an acute hospital in one Scottish health board covering 10% of the Scottish population. The participants (n = 6724) were older people (aged ≥ 65 years) with or without a cognitive spectrum disorder who were admitted as medical emergencies between January 2012 and December 2013 and who underwent a structured nurse assessment. ‘Cognitive spectrum disorder’ was defined as any combination of delirium, known dementia or an Abbreviated Mental Test score of < 8 out of 10 points. The main outcome measures were living at home 30 days after discharge, mortality within 2 years of admission, length of stay, re-admission within 2 years of admission and cost.

Data sources

Scottish Morbidity Records 01 was linked to the Older Persons Routine Acute Assessment data set.

Results

In the systematic review, methodological heterogeneity, especially concerning diagnostic criteria, means that there is significant overlap in conditions of patients presenting to general hospitals with confusion. Patients and their families expect that patients are discharged in the same or a better condition than they were in on admission or, failing that, that they have a satisfactory experience of their admission. Cognitive spectrum disorders were present in more than one-third of patients aged ≥ 65 years, and in over half of those aged ≥ 85 years. Outcomes were worse in those patients with cognitive spectrum disorders than in those without: length of stay 25.0 vs. 11.8 days, 30-day mortality 13.6% vs. 9.0%, 1-year mortality 40.0% vs. 26.0%, 1-year mortality or re-admission 62.4% vs. 51.5%, respectively (all p < 0.01). There was relatively little difference by cognitive spectrum disorder type; for example, the presence of any cognitive spectrum disorder was associated with an increased mortality over the entire period of follow-up, but with different temporal patterns depending on the type of cognitive spectrum disorder. The cost of admission was higher for those with cognitive spectrum disorders, but the average daily cost was lower.

Limitations

A lack of diagnosis and/or standardisation of diagnosis for dementia and/or delirium was a limitation for the systematic review, the quantitative study and the economic study. The economic study was limited to in-hospital costs as data for social or informal care costs were unavailable. The survey was conducted online, limiting its reach to older carers and those people with cognitive spectrum disorders.

Conclusions

Cognitive spectrum disorders are common in older inpatients and are associated with considerably worse health-care outcomes, with significant overlap between individual cognitive spectrum disorders. This suggests the need for health-care systems to systematically identify and develop care pathways for older people with cognitive spectrum disorders, and avoid focusing on only condition-specific pathways.

Future work

Development and evaluation of a multidomain intervention for the management of patients with cognitive spectrum disorders in hospital.

Study registration

This study is registered as PROSPERO CRD42015024492.

Funding

This project was funded by the National Institute for Health Research (NIHR) Health Services and Delivery Research programme and will be published in full in Health Services and Delivery Research; Vol. 9, No. 8. See the NIHR Journals Library website for further project information.

Delirium superimposed on dementia

PURPOSE

Delirium superimposed on dementia (DSD) is a frequent and growing emerging clinical challenge, given the increasing prevalence of dementia.

METHODS

This narrative review focuses on and discusses the current knowledge on epidemiology, pathogenesis, diagnosis and management of DSD.

RESULTS

There is a close interaction between delirium and dementia since dementia is a risk factor for delirium and delirium is a known risk factor for newly developed dementia or worsening of dementia. The occurrence of DSD causes adverse clinical outcomes. However, DSD is often under-recognized or is frequently considered as the regular course of dementia. Indeed, especially in the advance stages of dementia, DSD diagnosis is challenging since a clear distinction between symptoms attributable to delirium and to dementia is difficult. Given the importance of DSD, it is essential to educate health care providers on the best approach for delirium management and treatment. It is now well recognized that delirium can be prevented using multicomponent interventions carried out by a multidisciplinary team targeting predisposing and precipitating risk factors for delirium. On the contrary, antipsychotics should only be used in patients with severe distressing symptoms and whose behavior means their safety or the safety of those around them is compromised, given the harmful of these medications in patients with pre-existing dementia.

CONCLUSIONS

It is essential to improve health care providers knowledge on DSD to improve the quality of care for an epidemiologically relevant though understudied population.

Delirium in patients with dementia and in children: Overlap of symptoms profile and possible role for future diagnosis

BACKGROUND

Delirium in the extremes of the age spectrum may show similarities in presentations, and these similarities may provide information to develop tools for the diagnosis of delirium superimposed on dementia (DSD). We sought to investigate the symptom profile and subtypes of delirium in patients with dementia, and in infants and preschool children.

METHODS

This was an exploratory analysis of previous prospective cohort studies that evaluated delirium with the DSM-IV criteria in patients with dementia, and in critically ill infants (< 2 years of age) and preschool children (2-5 years of age), respectively. Delirium subtypes were defined based on the Richmond Agitation-Sedation Scale.

RESULTS

We included 147 patients, 35 adult patients with delirium DSD, 80 infants, and 32 preschool children with delirium. Hypokinesia and apathy were common among both DSD (72%), infants (74%) and preschool children (75%) with delirium, whereas hallucinations and anxiety were less common in both adults with DSD (26%) and infants (10%) and preschool children (14%). Hypoactive delirium was most common delirium subtype among infants (68%) and preschoolers (76%), whereas RASS = 0 (alert) delirium was the most common among adult patients with DSD (55%).

CONCLUSIONS

The study reports similarities in the symptoms profile of delirium in a cohort of patients with dementia and delirium, and in infants and preschool-aged children with delirium. These preliminary findings might be informative to design future studies adapting delirium assessments used in in infants and preschool-aged children to patients with dementia, especially in the moderate to severe stages.

Is Delirium the Cognitive Harbinger of Frailty in Older Adults? A Review about the Existing Evidence

Frailty is a clinical syndrome defined by the age-related depletion of the individual’s homeostatic reserves, determining an increased susceptibility to stressors and disproportionate exposure to negative health changes. The physiological systems that are involved in the determination of frailty are mutually interrelated, so that when decline starts in a given system, implications may also regard the other systems. Indeed, it has been shown that the number of abnormal systems is more predictive of frailty than those of the abnormalities in any particular system. Delirium is a transient neurocognitive disorder, characterized by an acute onset and fluctuating course, inattention, cognitive dysfunction, and behavioral abnormalities, that complicates one out of five hospital admissions. Delirium is independently associated with the same negative outcomes of frailty and, like frailty, its pathogenesis is usually multifactorial, depending on complex inter-relationships between predisposing and precipitating factors. By definition, a somatic cause should be identified, or at least suspected, to diagnose delirium. Delirium and frailty potentially share multiple pathophysiologic mechanisms and pathways, meaning that they could be thought of as the two sides to the same coin. This review aims at summarizing the existing evidence, referring both to human and animal models, to postulate that delirium may represent the cognitive harbinger of a state of frailty in older persons experiencing an acute clinical event.

The association between cognitive impairment and functional outcome in hospitalised older patients: a systematic review and meta-analysis

Background

in hospitalised older adults, cognitive impairments are common and may be associated with functional outcomes. Our aim was to systematically review this association.

Method

we systematically searched MEDLINE, CINAHL, AMED and PsycINFO from inception to April 2016. Non-English language studies were filtered out at search stage. All types of studies were considered for inclusion except reviews, conference abstracts, dissertations and case studies. Population: community-dwelling or institutionalised older adults aged 65 years or more, who are acutely hospitalised and have information on history of dementia and/or cognitive scores on admission. Setting: acute hospital (excluding critical care and subacute or intermediate care). Outcome of interest: change in a measure of physical function or disability between pre-admission or admission, and discharge or post-discharge. This review was registered on PROSPERO (CRD42016035978).

Results

the search returned 5,988 unique articles, of which 34 met inclusion criteria. All studies were observational, with 30 prospective and 4 retrospective from 14 countries, recruiting from general medicine (n = 11), geriatric medicine (n = 11) and mixed (n = 12) wards. Twenty-six studies (54,637 participants) were suitable for the quantitative synthesis. The meta-analysis suggested that cognitive impairment was associated with functional decline in hospitalised older adults (risk ratio (RR): 1.64; 95% confidence interval (CI): 1.45-1.86; P < 0.01). Results were similar in subanalyses focusing on diagnosis of dementia (RR: 1.36; 95% CI: 1.05-1.76; P = 0.02; n= 2,248) or delirium (RR: 1.55; 95% CI: 1.31-1.83; P < 0.01; n= 1,677).

Conclusion

cognitive impairments seem associated with functional decline in hospitalised older people. Causality cannot be inferred, and limitations include low quality of studies and possible confounding.

Systemic TNF-α produces acute cognitive dysfunction and exaggerated sickness behavior when superimposed upon progressive neurodegeneration

Inflammation influences chronic neurodegeneration but its precise roles are not yet clear. Systemic inflammation caused by infection, trauma or co-morbidity can alter the brain's inflammatory status, produce acute cognitive impairments, such as delirium, and drive new pathology and accelerated decline. Consistent with this, elevated systemic TNF-α is associated with more rapid cognitive decline over 6months in Alzheimer's disease patients. In the current study we challenged normal animals and those with existing progressive neurodegeneration (ME7 prion disease) with TNF-α (i.p.) to test the hypothesis that this cytokine has differential effects on cognitive function, sickness behavior and features of underlying pathology contingent on the animals' baseline condition. TNF-α (50μg/kg) had no impact on performance of normal animals (normal brain homogenate; NBH) on working memory (T-maze) but produced acute impairments in ME7 animals similarly challenged. Plasma TNF-α and CCL2 levels were equivalent in NBH and ME7 TNF-challenged animals but hippocampal and hypothalamic transcription of IL-1β, TNF-α and CCL2 and translation of IL-1β were higher in ME7+TNF-α than NBH+TNF-α animals. TNF-α produced an exaggerated sickness behavior response (hypothermia, weight loss, inactivity) in ME7 animals compared to that in NBH animals. However a single challenge with this dose was not sufficient to produce de novo neuronal death, synaptic loss or tau hyperphosphorylation that was distinguishable from that arising from ME7 alone. The data indicate that acutely elevated TNF-α has robust acute effects on brain function, selectively in the degenerating brain, but more sustained levels may be required to significantly impact on underlying neurodegeneration.

A systematic review and meta-analysis of the association between the apolipoprotein E genotype and delirium

The role of apolipoprotein E (APOE) in Alzheimer's disease and other dementias has been investigated intensively. However, the relationship between APOE and delirium has only recently been explored in studies that have included relatively small samples. A meta-analysis of the published pooled data is timely to explore the relationship between APOE and delirium and to inform further research in this topic. PubMed, EBSCOhost, Google Scholar, Scopus, all EBM Reviews (OVID) and the Cochrane Database of Systematic Reviews were searched with relevant keywords and from the references of relevant papers. Ten papers were found that examined the relationship between APOE and delirium. Data were extracted from eight of them and pooled for meta-analysis using random effects with R software. Data from 1762 participants, of whom 479 (27.2%) were diagnosed with delirium, showed low heterogeneity (Q=13.11, d.f.=7, P=0.07; I=44.86%). The possession of the APOE ε4 allele has a small (log odds ratio: 0.18, 95% confidence interval: 0.23-0.59), nonsignificant (P=0.38) effect on the presence of delirium. No publication bias was identified. The metapower of the pooled data was low (α=0.05, power=0.65). On analysing the studies to date, it seems that there is no association between APOE and the occurrence of delirium. We suggest that further studies are needed with greater number of patients to clarify any association as well as to examine for other patterns of association including relevance for subgroups of patients who develop delirium and for effects on the phenotype of delirium and the outcomes.

The Diagnosis of Delirium Superimposed on Dementia: An Emerging Challenge

Delirium occurring in patients with dementia is referred to as delirium superimposed on dementia (DSD). People who are older with dementia and who are institutionalized are at increased risk of developing delirium when hospitalized. In addition, their prior cognitive impairment makes detecting their delirium a challenge. The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition and the International Statistical Classification of Diseases and Related Health Problems, 10th Revision are considered the standard reference for the diagnosis of delirium and include criteria of impairments in cognitive processes such as attention, additional cognitive disturbances, or altered level of arousal. The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition and the International Statistical Classification of Diseases and Related Health Problems, 10th Revision does not provide guidance regarding specific tests for assessment of the cognitive process impaired in delirium. Importantly, the assessment or inclusion of preexisting cognitive impairment is also not addressed by these standards. The challenge of DSD gets more complex as types of dementia, particularly dementia with Lewy bodies, which has features of both delirium and dementia, are considered. The objective of this article is to critically review key elements for the diagnosis of DSD, including the challenge of neuropsychological assessment in patients with dementia and the influence of particular tests used to diagnose DSD. To address the challenges of DSD diagnosis, we present a framework for guiding the focus of future research efforts to develop a reliable reference standard to diagnose DSD. A key feature of a reliable reference standard will improve the ability to clinically diagnose DSD in facility-based patients and research studies.

Association of cognition with functional trajectories in patients admitted to geriatric wards: A retrospective observational study

AIM

Impaired cognition is common among older patients admitted to acute hospitals, but its association with functional trajectories has not been well studied.

METHODS

A retrospective observational study was carried out in an English tertiary university hospital. We analyzed all first episodes of county residents aged ≥75 years admitted to the Department of Medicine for the Elderly wards between December 2014 and May 2015. A history of dementia or a cognitive concern in the absence of a known diagnosis of dementia were recorded on admission. A cognitive concern included possible undiagnosed dementia or delirium. Function was retrospectively measured with the modified Rankin Scale at preadmission baseline, admission and discharge.

RESULTS

There were 663 first hospital episodes over the period, of which 590 patients survived. Among the latter, 244 had no cognitive impairment, 134 a diagnosis of dementia, 66 a cognitive concern in the absence of a known dementia and 146 had missing cognitive data. When frailty, acuity, age and comorbidity were controlled for, people with known dementia had a similar functional recovery compared with those with no cognitive impairment. People with a cognitive concern, but no known dementia, had lesser functional recovery and greater disability at discharge than those with no cognitive impairment (mean discharge modified Rankin Scale 3.4 compared with 3.1, P = 0.011).

CONCLUSIONS

Dementia per se might not be a marker of poor rehabilitation potential. Older people with acute cognitive concerns might be more vulnerable to poor functional recovery. Our cognitive variables are not gold standard, and further research is required to clarify this relationship. Geriatr Gerontol Int 2017; 17: 1438-1443.

Evaluating attention in delirium: A comparison of bedside tests of attention

AIM

Impaired attention is a core diagnostic feature for delirium. The present study examined the discriminating properties for patients with delirium versus those with dementia and/or no neurocognitive disorder of four objective tests of attention: digit span, vigilance "A" test, serial 7s subtraction and months of the year backwards together with global clinical subjective rating of attention.

METHODS

This as a prospective study of older patients admitted consecutively in a general hospital. Participants were assessed using the Confusion Assessment Method, Delirium Rating Scale-98 Revised and Montreal Cognitive Assessment scales, and months of the year backwards. Pre-existing dementia was diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders fourth edition criteria.

RESULTS

The sample consisted of 200 participants (mean age 81.1 ± 6.5 years; 50% women; pre-existing cognitive impairment in 126 [63%]). A total of 34 (17%) were identified with delirium (Confusion Assessment Method +). The five approaches to assessing attention had statistically significant correlations (P < 0.05). Discriminant analysis showed that clinical subjective rating of attention in conjunction with the months of the year backwards had the best discriminatory ability to identify Confusion Assessment Method-defined delirium, and to discriminate patients with delirium from those with dementia and/or normal cognition. Both of these approaches had high sensitivity, but modest specificity.

CONCLUSION

Objective tests are useful for prediction of non-delirium, but lack specificity for a delirium diagnosis. Global attentional deficits were more indicative of delirium than deficits of specific domains of attention. Geriatr Gerontol Int 2016; 16: 1028-1035.

Diagnostic and treatment practices of delirium in a general hospital

BACKGROUND

Despite the increase in research on delirium, it remains underdiagnosed and difficult to manage, and the outcome is poor especially in older people.

AIMS

To identify the clinically diagnosed rates of delirium, the possible aetiologies, to describe treatment, number and type of psychotropic medication used and to investigate the reasons for referral to a liaison psychiatric team.

METHODS

Retrospective study of medical records of inpatients admitted to Sligo Regional Hospital during an 18-month period.

RESULTS

One hundred and fifty-six files had a documentation of delirium (time prevalence 2%). Mean age of the sample was 82 years (SD = 7.2), 66 (42%) were male. Sixty-nine (44.2%) of the total sample had a previous history of dementia, and 57 (36.5%) had a previous history of delirium. In 67 (43.2%) samples, the cause was infection, while in 4, no specific cause was identified. Ninety (58%) were referred to the liaison service, but only in 26 (28.9 %), the reason for referral was "acute confusion" or "delirium". In a majority of referrals, the reason was an affective disorder more often depression. There were no significant differences between delirium subtypes and referrals (χ(2) = 3.868, df 3, p = 0.28). Examination of the amount of antipsychotics prescribed before, during and after delirium shows that there was a significant increase in use during the delirium (χ(2) = 17.512, df 8, p = 0.025) and decrease in z-hypnotics medication (zopiclone/zolpidem), (χ(2) = 20.114, df 4, p < 0.001), while benzodiazepines and antidepressants remained the same.

CONCLUSIONS

Delirium is often misdiagnosed and unrecognized in hospital settings; however, when identified the pharmacological management is appropriate.

Phenomenological and biological correlates of improved cognitive function in hospitalized elderly medical inpatients

Deterioration of cognitive ability is a recognized outcome following acute illness in older patients. Levels of circulating cytokines and APOE genotype have both been linked with acute illness-related cognitive decline. In this observational longitudinal study, consecutive admissions to an elderly medical unit of patients aged ≥70 years were assessed within 3 days and re-assessed twice weekly with a range of scales assessing cognitive function, functional status and illness severity. Cytokines and APOE genotype were measured in a subsample. Improvement was defined as either a 20% or three points increase in mini mental state examination (MMSE). From the 142 participants 55 (39%) experienced cognitive improvement, of which 30 (54.5%) had delirium while 25 had non-delirious acute cognitive disorder. Using bivariate statistics, subjects with more severe acute illness, lower insulin-like growth factor-I (IGF-I) levels and more severe delirium were more likely to experience a ≥20% improvement in MMSE scores. When the criterion of cognitive improvement was a 3 point improvement in MMSE, those with more severe delirium, females and older were more likely to be improved. Longitudinal analysis using any criterion of improvement indicated that improvement was significantly (p<.05) predicted by higher levels of IGF-I, lower levels of IL-1 (alpha and beta), lack of APOE epsilon 4 allele, and female gender. In conclusion, cognitive recovery during admission is not exclusively linked to delirium status, but reflects a range of factors. The character and relevance of non-delirious acute cognitive disorder warrants further study.