Association between components of the delirium syndrome and outcomes in hospitalised adults: a systematic review and meta-analysis.

BACKGROUND: Delirium is a heterogeneous syndrome with inattention as the core feature. There is considerable variation in the presence and degree of other symptom domains such as altered arousal, psychotic features and global cognitive dysfunction. Delirium is independently associated with increased mortality, but it is unclear whether individual symptom domains of delirium have prognostic importance. We conducted a systematic review and meta-analysis of studies in hospitalised adults in general settings to identify the relationship between symptom domains of delirium and outcomes. (PROSPERO: CRD42018093935). METHODS: We searched MEDLINE, EMBASE, PsycINFO, CINAHL, clinicaltrials.gov and the Cochrane Central Register of Controlled Trials from inception to November 2019. We included studies of hospitalised adults that reported associations between symptom domains of delirium and 30-day mortality (primary outcome), and other outcomes including mortality at other time points, length of stay, and dementia. Reviewer pairs independently screened articles, extracted data, and assessed risk of bias (Risk of Bias Assessment tool for Non-randomized Studies) and quality of evidence using the Grading of Recommendations, Assessment, Development and Evaluation framework. We performed random-effects meta-analyses stratified by delirium domain where possible. RESULTS: From 7092 citations we included 6 studies (6002 patients, 1112 with delirium). Higher mortality (ranging from in-hospital to follow-up beyond 12 months) was associated with altered arousal (pooled Odds Ratio (OR) 2.80, 95% Confidence Interval (CI) 2.33-3.37; moderate-quality evidence), inattention (pooled OR 2.57, 95% CI 1.74-3.80; low-quality evidence), and in single studies with disorientation, memory deficits and disorganised thoughts. Risk of bias varied across studies but was moderate-to-high overall, mainly due to selection bias, lack of blinding of assessments and unclear risk of selective outcome reporting. We found no studies on the association between psychotic features, visuospatial deficits or affective disturbances in delirium and outcomes, or studies reporting non-mortality outcomes. CONCLUSIONS: Few studies have related symptom domains of delirium to outcomes, but the available evidence suggests that altered arousal and inattention in delirium are associated with higher mortality than normal arousal and attention in people with or without delirium. Measurable symptom domains of delirium may have value in predicting survival and stratifying patients for treatment. We recommend that future delirium studies report outcomes by symptom domain

Detecting delirium superimposed on dementia: diagnostic accuracy of a simple combined arousal and attention testing procedure

Detecting delirium superimposed on dementia (DSD) can be challenging because assessment partly relies on cognitive tests that may be abnormal in both conditions. We hypothesized that a combined arousal and attention testing procedure would accurately detect DSD. Patients aged ≥70 years were recruited from five hospitals across Europe. Delirium was diagnosed by physicians using DSM-5 criteria using information from nurses, carers, and medical records. Dementia was ascertained by the Informant Questionnaire on Cognitive Decline in the Elderly. Arousal was measured using the Observational Scale of Level of Arousal (OSLA), which assesses eye opening, eye contact, posture, movement, and communication. Attention was measured by participants signaling each time an “A” was heard when “S-A-V-E-A-H-A-A-R-T” was read out. The sample included 114 persons (mean age 82 years (SD 7); 54% women). Dementia alone was present in 25% (n = 28), delirium alone in 18% (n = 21), DSD in 27% (n = 31), and neither in 30% (n = 34). Arousal and attention was assessed in n = 109 (96%). Using OSLA, 83% participants were correctly identified as having delirium (sensitivity 85%, specificity 82%, AUROC 0.92). The attention task correctly classified 76% of participants with delirium (sensitivity 90%, specificity 64%, AUROC 0.80). Combining scores correctly classified 91% of participants with delirium (sensitivity 84%, specificity 92%, AUROC 0.94). Diagnostic accuracy remained high in the subgroup with dementia (93% correctly classified, sensitivity 94%, specificity 92%, AUROC 0.98). This combined arousal–attention assessment to detect DSD was brief yet had high diagnostic accuracy. Such an approach could have clinical utility for diagnosing DSD

A systematic review of studies reporting on neuropsychological and functional domains used for assessment of recovery from delirium in acute hospital patients

Objectives: Assessing for recovery in delirium is essential in guiding ongoing investigation and treatment. Yet, there is little scrutiny and no research or clinical consensus on how recovery should be measured. We reviewed studies which used tests of neuropsychological domains and functional ability to track recovery of delirium longitudinally in acute hospital settings. / Methods/Design: We systematically searched databases (MEDLINE, PsycInfo, CINAHL, Embase, ClinicalTrials.gov, Cochrane Central Register of Controlled Trials), from inception to October 14th, 2022. Inclusion criteria were: adult acute hospital patients (≥18 years) diagnosed with delirium by a validated tool; 1+ repeat assessment using an assessment tool measuring domains of delirium/functional recovery ≤7 days from baseline. Two reviewers independently screened articles, performed data extraction, and assessed risk of bias. A narrative data synthesis was completed. / Results: From 6533 screened citations, we included 39 papers (reporting 32 studies), with 2370 participants with delirium. Studies reported 21 tools with an average of four repeat assessments including baseline (range 2–10 assessments within ≤7 days), measuring 15 specific domains. General cognition, functional ability, arousal, attention and psychotic features were most commonly assessed for longitudinal change. Risk of bias was moderate to high for most studies. / Conclusions: There was no standard approach for tracking change in specific domains of delirium. The methodological heterogeneity of studies was too high to draw firm conclusions on the effectiveness of assessment tools to measure delirium recovery. This highlights the need for standardised methods for assessing recovery from delirium

Increasing delirium skills at the front door: results from a repeated survey on delirium knowledge and attitudes

Background: delirium is under-recognised in comparison to other common and serious acute disorders. A 2006 survey of UK junior doctors (not undertaking specialist training) identified poor knowledge of the diagnostic criteria and treatment of delirium. We hypothesised that increased prominence accorded to delirium in the form of national initiatives and guidelines may have had an impact on understanding among junior doctors. Objective: we repeated a multi-centre survey of knowledge of and attitudes to delirium in junior doctors (not undertaking specialist training) assessing unselected acute medical presentations (the ‘medical take’). Design: questionnaire-based survey in 48 acute hospitals in UK and Ireland. Methods: we used questionnaires designed to test understanding of delirium, including prevalence, knowledge of the DSMIV diagnostic criteria, use of specific screening tools, association with adverse outcomes and pharmacological management. Results: one thousand two hundred and fifteen trainee physicians participated. Compared with the 2006 cohort, improvements were seen in 9 of 17 knowledge-based questions and overall score improved in the 2013 cohort. Nonetheless, significant deficits in knowledge, particularly for the diagnostic criteria for delirium, remained. Conclusions: despite improvements in some aspects of delirium knowledge, the diagnostic criteria for delirium remain poorly understood. Challenges remain in ensuring adequate training for junior doctors in delirium

Dissociable effects of 5-HT2C receptor antagonism and genetic inactivation on perseverance and learned non-reward in an egocentric spatial reversal task

Cognitive flexibility can be assessed in reversal learning tests, which are sensitive to modulation of 5-HT2C receptor (5-HT2CR) function. Successful performance in these tests depends on at least two dissociable cognitive mechanisms which may separately dissipate associations of previous positive and negative valence. The first is opposed by perseverance and the second by learned non-reward. The current experiments explored the effect of reducing function of the 5-HT2CR on the cognitive mechanisms underlying egocentric reversal learning in the mouse. Experiment 1 used the 5-HT2CR antagonist SB242084 (0.5 mg/kg) in a between-groups serial design and Experiment 2 used 5-HT2CR KO mice in a repeated measures design. Animals initially learned to discriminate between two egocentric turning directions, only one of which was food rewarded (denoted CS+, CS−), in a T- or Y-maze configuration. This was followed by three conditions; (1) Full reversal, where contingencies reversed; (2) Perseverance, where the previous CS+ became CS− and the previous CS− was replaced by a novel CS+; (3) Learned non-reward, where the previous CS− became CS+ and the previous CS+ was replaced by a novel CS-. SB242084 reduced perseverance, observed as a decrease in trials and incorrect responses to criterion, but increased learned non-reward, observed as an increase in trials to criterion. In contrast, 5-HT2CR KO mice showed increased perseverance. 5-HT2CR KO mice also showed retarded egocentric discrimination learning. Neither manipulation of 5-HT2CR function affected performance in the full reversal test. These results are unlikely to be accounted for by increased novelty attraction, as SB242084 failed to affect performance in an unrewarded novelty task. In conclusion, acute 5-HT2CR antagonism and constitutive loss of the 5-HT2CR have opposing effects on perseverance in egocentric reversal learning in mice. It is likely that this difference reflects the broader impact of 5HT2CR loss on the development and maintenance of cognitive function

A rehabilitation intervention to improve recovery after an episode of delirium in adults over 65 years (RecoverED): study protocol for a multi-centre, single-arm feasibility study

Background: Delirium affects over 20% of all hospitalised older adults. Delirium is associated with a number of adverse outcomes following hospital admission including cognitive decline, anxiety and depression, increased mortality and care needs. Previous research has addressed prevention of delirium in hospitals and care homes, and there are guidelines on short-term treatment of delirium during admission. However, no studies have addressed the problem of longer-term recovery after delirium and it is currently unknown whether interventions to improve recovery after delirium are effective and cost-effective. The primary objective of this feasibility study is to test a new, theory-informed rehabilitation intervention (RecoverED) in older adults delivered following a hospital admission complicated by delirium to determine whether (a) the intervention is acceptable to individuals with delirium and (b) a definitive trial and parallel economic evaluation of the intervention are feasible. Methods: The study is a multi-centre, single-arm feasibility study of a rehabilitation intervention with an embedded process evaluation. Sixty participants with delirium (aged > 65 years old) and carer pairs will be recruited from six NHS acute hospitals across the UK. All pairs will be offered the intervention, with follow-up assessments conducted at 3 months and 6 months post-discharge home. The intervention will be delivered in participants’ own homes by therapists and rehabilitation support workers for up to 10 intervention sessions over 12 weeks. The intervention will be tailored to individual needs, and the chosen intervention plan and goals will be discussed and agreed with participants and carers. Quantitative data on reach, retention, fidelity and dose will be collected and summarised using descriptive statistics. The feasibility outcomes that will be used to determine whether the study meets the criteria for progression to a definitive randomised controlled trial (RCT) include recruitment, delivery of the intervention, retention, data collection and acceptability of outcome measures. Acceptability of the intervention will be assessed using in-depth, semi-structured qualitative interviews with participants and healthcare professionals. Discussion: Findings will inform the design of a pragmatic multi-centre RCT of the effectiveness and cost-effectiveness of the RecoverED intervention for helping the longer-term recovery of people with delirium compared to usual care. Trial registration: The feasibility study was registered: ISRCTN1567657

Association of Delirium With Cognitive Decline in Late Life: A Neuropathologic Study of 3 Population-Based Cohort Studies

Importance: Delirium is associated with accelerated cognitive decline. The pathologic substrates of this association are not yet known, that is, whether they are the same as those associated with dementia, are independent, or are interrelated. Objective: To examine whether the accelerated cognitive decline observed after delirium is independent of the pathologic processes of classic dementia. Design, Setting, and Participants: Harmonized data from 987 individual brain donors from 3 observational cohort studies with population-based sampling (Vantaa 85+, Cambridge City Over-75s Cohort, Cognitive Function and Ageing Study) performed from January 1, 1985, through December 31, 2011, with a median follow-up of 5.2 years until death, were used in this study. Neuropathologic assessments were performed with investigators masked to clinical data. Data analysis was performed from January 1, 2012, through December 31, 2013. Clinical characteristics of brain donors were not different from the rest of the cohort. Outcome ascertainment was complete given that the participants were brain donors. Exposures: Delirium (never vs ever) and pathologic burden of neurofibrillary tangles, amyloid plaques, vascular lesions, and Lewy bodies. Effects modeled using random-effects linear regression and interactions between delirium and pathologic burden were assessed. Outcomes: Change in Mini-Mental State Examination (MMSE) scores during the 6 years before death. Results: There were 987 participants (290 from Vantaa 85+, 241 from the Cambridge City Over-75s Cohort, and 456 from the Cognitive Function and Ageing Study) with neuropathologic data; mean (SD) age at death was 90 (6.4) years, including 682 women (69%). The mean MMSE score 6 years before death was 24.7 points. The 279 individuals with delirium (75% women) had worse initial scores (−2.8 points; 95% CI, −4.5 to −1.0; P < .001). Cognitive decline attributable to delirium was −0.37 MMSE points per year (95% CI, −0.60 to −0.13; P < .001). Decline attributable to the pathologic processes of dementia was −0.39 MMSE points per year (95% CI, −0.57 to −0.22; P < .001). However, the combination of delirium and the pathologic processes of dementia resulted in the greatest decline, in which the interaction contributed an additional −0.16 MMSE points per year (95% CI, −0.29 to −0.03; P = .01). The multiplicative nature of these variables resulted in individuals with delirium and the pathologic processes of dementia declining 0.72 MMSE points per year faster than age-, sex-, and educational level–matched controls. Conclusions and Relevance: Delirium in the presence of the pathologic processes of dementia is associated with accelerated cognitive decline beyond that expected for delirium or the pathologic process itself. These findings suggest that additional unmeasured pathologic processes specifically relate to delirium. Age-related cognitive decline has many contributors, and these findings at the population level support a role for delirium acting independently and multiplicatively to the pathologic processes of classic dementia

Lattice Boltzmann simulations in microfluidics: probing the no-slip boundary condition in hydrophobic, rough, and surface nanobubble laden microchannels

In this contribution we review recent efforts on investigations of the effect of (apparent) boundary slip by utilizing lattice Boltzmann simulations. We demonstrate the applicability of the method to treat fundamental questions in microfluidics by investigating fluid flow in hydrophobic and rough microchannels as well as over surfaces covered by nano- or microscale gas bubbles.Comment: 11 pages, 6 figure

Association of Delirium With Cognitive Decline in Late Life: A Neuropathologic Study of 3 Population-Based Cohort Studies

Importance: Delirium is associated with accelerated cognitive decline. The pathologic substrates of this association are not yet known, that is, whether they are the same as those associated with dementia, are independent, or are interrelated. Objective: To examine whether the accelerated cognitive decline observed after delirium is independent of the pathologic processes of classic dementia. Design, Setting, and Participants: Harmonized data from 987 individual brain donors from 3 observational cohort studies with population-based sampling (Vantaa 85+, Cambridge City Over-75s Cohort, Cognitive Function and Ageing Study) performed from January 1, 1985, through December 31, 2011, with a median follow-up of 5.2 years until death, were used in this study. Neuropathologic assessments were performed with investigators masked to clinical data. Data analysis was performed from January 1, 2012, through December 31, 2013. Clinical characteristics of brain donors were not different from the rest of the cohort. Outcome ascertainment was complete given that the participants were brain donors. Exposures: Delirium (never vs ever) and pathologic burden of neurofibrillary tangles, amyloid plaques, vascular lesions, and Lewy bodies. Effects modeled using random-effects linear regression and interactions between delirium and pathologic burden were assessed. Outcomes: Change in Mini-Mental State Examination (MMSE) scores during the 6 years before death. Results: There were 987 participants (290 from Vantaa 85+, 241 from the Cambridge City Over-75s Cohort, and 456 from the Cognitive Function and Ageing Study) with neuropathologic data; mean (SD) age at death was 90 (6.4) years, including 682 women (69%). The mean MMSE score 6 years before death was 24.7 points. The 279 individuals with delirium (75% women) had worse initial scores (-2.8 points; 95% CI, -4.5 to -1.0; P < .001). Cognitive decline attributable to delirium was -0.37 MMSE points per year (95% CI, -0.60 to -0.13; P < .001). Decline attributable to the pathologic processes of dementia was -0.39 MMSE points per year (95% CI, -0.57 to -0.22; P < .001). However, the combination of delirium and the pathologic processes of dementia resulted in the greatest decline, in which the interaction contributed an additional -0.16 MMSE points per year (95% CI, -0.29 to -0.03; P = .01). The multiplicative nature of these variables resulted in individuals with delirium and the pathologic processes of dementia declining 0.72 MMSE points per year faster than age-, sex-, and educational level-matched controls. Conclusions and Relevance: Delirium in the presence of the pathologic processes of dementia is associated with accelerated cognitive decline beyond that expected for delirium or the pathologic process itself. These findings suggest that additional unmeasured pathologic processes specifically relate to delirium. Age-related cognitive decline has many contributors, and these findings at the population level support a role for delirium acting independently and multiplicatively to the pathologic processes of classic dementia.The Cambridge Brain Bank Laboratory (which processed all the CC75C and some of the CFAS cases) is supported by the National Institute for Health Research Cambridge BioMedical Research Centre. The original Epidemiological Clinicopathological Studies in Europe (EClipSE) harmonization project was established through grant RHAG/094 from the Bupa UK Foundation and a European Union Marie Curie International Incoming Fellowship (Dr Keage). Dr Fleming is supported by grant RHAG/058 from the Bupa UK Foundation, which included the latest CC75C fieldwork funding. Dr Davis is supported by grants 090661/Z/09/Z and 107467/Z/15/Z from the Wellcome Trust. Drs Davis and MacLullich are members of The University of Edinburgh Centre for Cognitive Ageing and Cognitive Epidemiology, part of the cross-council Lifelong Health and Wellbeing Initiative funded by grant G0700704/84698. Funding from the Biotechnology and Biological Sciences Research Council, Engineering and Physical Sciences Research Council, Economic and Social Research Council, and the Medical Research Council is gratefully acknowledged. Dr Keage is supported by Australian National Health and Medical Research Council Fellowship grant 568890. Dr Cunningham is supported by grant 09/09/07 from the Wellcome Trust Senior Research Fellowship

Potential barriers and facilitators for implementation of an integrated care pathway for hearing-impaired persons: an exploratory survey among patients and professionals

BACKGROUND: Because of the increasing costs and anticipated shortage of Ear Nose and Throat (ENT) specialists in the care for hearing-impaired persons, an integrated care pathway that includes direct hearing aid provision was developed. While this direct pathway is still under investigation, in a survey we examined expectations and potential barriers and facilitators towards this direct pathway, of patients and professionals involved in the pathway. METHODS: Two study populations were assessed: members of the health professions involved in the care pathway for hearing-impaired persons (general practitioners (GPs), hearing aid dispensers, ENT-specialists and clinical audiologists) and persons with hearing complaints. We developed a comprehensive semi-structured questionnaire for the professionals, regarding expectations, barriers, facilitators and conditions for implementation. We developed two questionnaires for persons with hearing complaints, both regarding evaluations and preferences, and administered them after they had experienced two key elements of the direct pathway: the triage and the hearing aid fitting. RESULTS: On average GPs and hearing aid dispensers had positive expectations towards the direct pathway, while ENT-specialists and clinical audiologists had negative expectations. Professionals stated both barriers and facilitators towards the direct pathway. Most professionals either supported implementation of the direct pathway, provided that a number of conditions were satisfied, or did not support implementation, unless roughly the same conditions were satisfied. Professionals generally agreed on which conditions need to be satisfied. Persons with hearing complaints evaluated the present referral pathway and the new direct pathway equally. Many, especially older, participants stated however that they would still visit the GP and ENT-specialist, even when this would not be necessary for reimbursement of the hearing aid, and found it important that the ENT-specialist or Audiological Centre evaluated their hearing aid. CONCLUSION: This study identified professional concerns about the direct pathway for hearing-impaired persons. Gaps exist in expectations amongst professions. Also gaps exist between users of the pathway, especially between age groups and regions. Professionals are united in the conditions that need to be fulfilled for a successful implementation of the direct pathway. Implementation on a regional level is recommended to best satisfy these conditions