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

Development and validation of a new drug-focused predictive risk score for postoperative delirium in orthopaedic and trauma surgery patients

BACKGROUND

Postoperative delirium (POD) is the most common complication following surgery in elderly patients. During pharmacist-led medication reconciliation (PhMR), a predictive risk score considering delirium risk-increasing drugs and other available risk factors could help to identify risk patients.

METHODS

Orthopaedic and trauma surgery patients aged ≥ 18 years with PhMR were included in a retrospective observational single-centre study 03/2022-10/2022. The study cohort was randomly split into a development and a validation cohort (6:4 ratio). POD was assessed through the 4 A's test (4AT), delirium diagnosis, and chart review. Potential risk factors available at PhMR were tested via univariable analysis. Significant variables were added to a multivariable logistic regression model. Based on the regression coefficients, a risk score for POD including delirium risk-increasing drugs (DRD score) was established.

RESULTS

POD occurred in 42/328 (12.8%) and 30/218 (13.8%) patients in the development and validation cohorts, respectively. Of the seven evaluated risk factors, four were ultimately tested in a multivariable logistic regression model. The final DRD score included age (66-75 years, 2 points; > 75 years, 3 points), renal impairment (eGFR < 60 ml/min/1.73m2, 1 point), anticholinergic burden (ACB-score ≥ 3, 1 point), and delirium risk-increasing drugs (n ≥ 2; 2 points). Patients with ≥ 4 points were classified as having a high risk for POD. The areas under the receiver operating characteristic curve of the risk score model were 0.89 and 0.81 for the development and the validation cohorts, respectively.

CONCLUSION

The DRD score is a predictive risk score assessable during PhMR and can identify patients at risk for POD. Specific preventive measures concerning drug therapy safety and non-pharmacological actions should be implemented for identified risk patients.

Requesting That Delirium Achieve Parity With Acute Encephalopathy in the MS-DRG System

Since 2007, the Medicare Severity Diagnosis Related Groups classification system has favored billing codes for acute encephalopathy over delirium codes in determining hospital reimbursement and several quality-of-care value metrics, despite broad overlap between these sets of diagnostic codes. Toxic and metabolic encephalopathy codes are designated as major complication or comorbidity, whereas causally specified delirium codes are designated as complication or comorbidity and thus associated with a lower reimbursement and lesser impact on value metrics. The authors led a submission to the U.S. Centers for Medicare and Medicaid Services requesting that causally specified delirium be designated major complication or comorbidity alongside toxic and metabolic encephalopathy. Delirium warrants reclassification because it satisfies U.S. Centers for Medicare and Medicaid Services' guiding principles for re-evaluating Medicare Severity Diagnosis Related Group severity levels. Delirium: (1) has a bidirectional relationship with the permanent condition of dementia (major neurocognitive disorder per DSM-5-TR), (2) indexes vulnerability across populations, (3) impacts healthcare systems across levels of care, (4) complicates postoperative recovery, (5) consigns patients to higher levels of care, (6) impedes patient engagement in care, (7) has several recent treatment guidelines, (8) often indicates neuronal/brain injury, and (9) represents a common expression of terminal illness. The proposal's impact was explored using the 2019 National Inpatient Sample, which suggested that increasing delirium's complexity designation would lead to an upcoding of less than 1% of eligible discharges. Parity for delirium is essential to enhancing awareness of delirium's clinical and economic costs. Appreciating delirium's impact would encourage delirium prevention and screening efforts, thereby mitigating its dire outcomes for patients, families, and healthcare systems.

Delirium detection tools show varying completion rates and positive score rates when used at scale in routine practice in general hospital settings: A systematic review

BACKGROUND

Multiple short delirium detection tools have been validated in research studies and implemented in routine care, but there has been little study of these tools in real-world conditions. This systematic review synthesized literature reporting completion rates and/or delirium positive score rates of detection tools in large clinical populations in general hospital settings.

METHODS

PROSPERO (CRD42022385166). Medline, Embase, PsycINFO, CINAHL, and gray literature were searched from 1980 to December 31, 2022. Included studies or audit reports used a validated delirium detection tool performed directly with the patient as part of routine care in large clinical populations (n ≥ 1000) within a general acute hospital setting. Narrative synthesis was performed.

RESULTS

Twenty-two research studies and four audit reports were included. Tools used alone or in combination were the Confusion Assessment Method (CAM), 4 'A's Test (4AT), Delirium Observation Screening Scale (DOSS), Brief CAM (bCAM), Nursing Delirium Screening Scale (NuDESC), and Intensive Care Delirium Screening Checklist (ICDSC). Populations and settings varied and tools were used at different stages and frequencies in the patient journey, including on admission only; inpatient, daily or more frequently; on admission and as inpatient; inpatient post-operatively. Tool completion rates ranged from 19% to 100%. Admission positive score rates ranged from: CAM 8%-51%; 4AT 13%-20%. Inpatient positive score rates ranged from: CAM 2%-20%, DOSS 6%-42%, and NuDESC 5-13%. Postoperative positive score rates were 21% and 28% (4AT). All but two studies had moderate-high risk of bias.

CONCLUSIONS

This systematic review of delirium detection tool implementation in large acute patient populations found clinically important variability in tool completion rates, and in delirium positive score rates relative to expected delirium prevalence. This study highlights a need for greater reporting and analysis of relevant healthcare systems data. This is vital to advance understanding of effective delirium detection in routine care.

Short-term outcomes of prehospital opioid pain management for older adults with fall-related injury

BACKGROUND

Opioids are recommended for pain management in patients being cared for and transported by emergency medical services, but no specific guidelines exist for older adults with fall-related injury. Prior research suggests prehospital opioid administration can effectively manage pain in older adults, but less is known about safety in this population. We compared short-term safety outcomes, including delirium, disposition, and length of stay, among older adults with fall-related injury according to whether they received prehospital opioid analgesia.

METHODS

We linked Medicare claims data with prehospital patient care reports for older adults (≥65) with fall-related injury in Illinois between January 1, 2014 and December 31, 2015. We used weighted regression models (logistic, multinomial logistic, and Poisson) to assess the association between prehospital opioid analgesia and incidence of inpatient delirium, hospital disposition, and length of stay.

RESULTS

Of 28,150 included older adults, 3% received prehospital opioids. Patients receiving prehospital opioids (vs. no prehospital opioids) were less likely to be discharged home from the emergency department (adjusted probability = 0.30 [95% CI: 0.25, 0.34] vs. 0.47 [95% CI: 0.46, 0.48]), more likely to be discharged to a non-home setting after an inpatient admission (adjusted probability = 0.43 [95% CI: 0.39, 0.48] vs. 0.30 [95% CI: 0.30, 0.31]), had inpatient length of stay 0.4 days shorter (p < 0.001) and ICU length of stay 0.7 days shorter (p = 0.045). Incidence of delirium did not vary between treatment and control groups.

CONCLUSIONS

Few older adults receive opioid analgesia in the prehospital setting. Prehospital opioid analgesia may be associated with hospital disposition and length of stay for older adults with fall-related injury. However, our findings do not provide evidence of an association with inpatient delirium. These findings should be considered when developing guidelines for prehospital pain management specific to the older adult population.

Causal relationship between dementia and delirium: Insights from a bidirectional two-sample Mendelian randomization analysis

BACKGROUND

Our previous study found dementia as a significant risk factor for delirium development in elderly patients with hip fracture. However, the causal relationship between dementia and delirium remains unclear.

METHODS

To assess the causal relationship between delirium and dementia, we conducted a bidirectional Mendelian randomization (MR) analysis. Inversevariance weighted (IVW), weighted median, MR Egger, weighted mode, and simple mode were employed to conduct the MR analysis. Heterogeneity was assessed using the Cochran Q statistic in MR-Egger and IVW methods. Horizontal pleiotropy was examined via the MR pleiotropy residual sum and outliers (MR-PRESSO) and MR-Egger intercept tests.

RESULTS

The forward MR analysis revealed a significant association between unclassified dementia (1.604 (1.326-1.941), p = 1.12 × 10-6), Alzheimer's disease (1.259 (1.128-1.405), p = 4.10 × 10-5), and dementia with Lewy bodies (1.121 (1.026-1.225), p = 0.011) with an increased risk of delirium. In the reverse MR analysis, delirium was also suggested to increase the risk of unclassified dementia (1.133 (1.066-1.204), p = 6.31 × 10-5) and vascular dementia (1.246 (1.075-1.444), p = 0.003). These significant results were further validated in the multivariable MR analysis. No evidence of heterogeneity or horizontal pleiotropy was observed (p > 0.05).

LIMITATIONS

(1) Limited to European populations. (2) Sample population overlap between delirium and dementia. (3) Not all dementia subtypes were causally associated with delirium.

CONCLUSIONS

This study provides genetic evidence supporting a causal relationship between dementia and delirium, indicating that dementia may influence the risk of delirium while delirium may also increase the risk of dementia.

Former smoking, but not active smoking, is associated with delirium in postoperative ICU patients: a matched case-control study

Objective

To examine the relationship between current and former smoking and the occurrence of delirium in surgical Intensive Care Unit (ICU) patients.

Methods

We conducted a single center, case-control study involving 244 delirious and 251 non-delirious patients that were admitted to our ICU between 2018 and 2022. Using propensity score analysis, we obtained 115 pairs of delirious and non-delirious patients matched for age and Simplified Acute Physiology Score II (SAPS II). Both groups of patients were further stratified into non-smokers, active smokers and former smokers, and logistic regression was performed to further investigate potential confounders.

Results

Our study revealed a significant association between former smoking and the incidence of delirium in ICU patients, both in unmatched (adjusted odds ratio (OR): 1.82, 95% confidence interval (CI): 1.17-2.83) and matched cohorts (OR: 3.0, CI: 1.53-5.89). Active smoking did not demonstrate a significant difference in delirium incidence compared to non-smokers (unmatched OR = 0.98, CI: 0.62-1.53, matched OR = 1.05, CI: 0.55-2.0). Logistic regression analysis of the matched group confirmed former smoking as an independent risk factor for delirium, irrespective of other variables like surgical history (p = 0.010). Notably, also respiratory and vascular surgeries were associated with increased odds of delirium (respiratory: OR: 4.13, CI: 1.73-9.83; vascular: OR: 2.18, CI: 1.03-4.59). Medication analysis showed that while Ketamine and Midazolam usage did not significantly correlate with delirium, Morphine use was linked to a decreased likelihood (OR: 0.27, 95% CI: 0.13-0.55).

Discussion

Nicotine's complex neuropharmacological impact on the brain is still not fully understood, especially its short-term and long-term implications for critically ill patients. Although our retrospective study cannot establish causality, our findings suggest that smoking may induce structural changes in the brain, potentially heightening the risk of postoperative delirium. Intriguingly, this effect seems to be obscured in active smokers, potentially due to the recognized neuroprotective properties of nicotine. Our results motivate future prospective studies, the results of which hold the potential to substantially impact risk assessment procedures for surgeries.

Plasma SOMAmer proteomics of postoperative delirium

BACKGROUND

Postoperative delirium is prevalent in older adults and has been shown to increase the risk of long-term cognitive decline. Plasma biomarkers to identify the risk for postoperative delirium and the risk of Alzheimer's disease and related dementias are needed.

METHODS

This biomarker discovery case-control study aimed to identify plasma biomarkers associated with postoperative delirium. Patients aged ≥65 years undergoing major elective noncardiac surgery were recruited. The preoperative plasma proteome was interrogated with SOMAmer-based technology targeting 1433 biomarkers.

RESULTS

In 40 patients (20 with vs. 20 without postoperative delirium), a preoperative panel of 12 biomarkers discriminated patients with postoperative delirium with an accuracy of 97.5%. The final model of five biomarkers delivered a leave-one-out cross-validation accuracy of 80%. Represented biological pathways included lysosomal and immune response functions.

CONCLUSION

In older patients who have undergone major surgery, plasma SOMAmer proteomics may provide a relatively non-invasive benchmark to identify biomarkers associated with postoperative delirium.

Infection, delirium, and risk of dementia in patients with and without white matter disease on previous brain imaging: a population-based study

BACKGROUND

The increased risk of dementia after delirium and infection might be influenced by cerebral white matter disease (WMD). In patients with transient ischaemic attack (TIA) and minor stroke, we assessed associations between hospital admissions with delirium and 5-year dementia risk and between admissions with infection and dementia risk, stratified by WMD severity (moderate or severe vs absent or mild) on baseline brain imaging.

METHODS

We included patients with TIA and minor stroke (National Institutes of Health Stroke Score <3) from the Oxford Vascular Study (OXVASC), a longitudinal population-based study of the incidence and outcomes of acute vascular events in a population of 94 567 individuals, with no age restrictions, attending eight general practices in Oxfordshire, UK. Hospitalisation data were obtained through linkage to the Oxford Cognitive Comorbidity, Frailty, and Ageing Research Database-Electronic Patient Records (ORCHARD-EPR). Brain imaging was done using CT and MRI, and WMD was prospectively graded according to the age-related white matter changes (ARWMC) scale and categorised into absent, mild, moderate, or severe WMD. Delirium and infection were defined by ICD-10 coding supplemented by hand-searching of hospital records. Dementia was diagnosed using clinical or cognitive assessment, medical records, and death certificates. Associations between hospitalisation with delirium and hospitalisation with infection, and post-event dementia were assessed using time-varying Cox analysis with multivariable adjustment, and all models were stratified by WMD severity.

FINDINGS

From April 1, 2002, to March 31, 2012, 1369 individuals were prospectively recruited into the study. Of 1369 patients (655 with TIA and 714 with minor stroke, mean age 72 [SD 13] years, 674 female and 695 male, and 364 with moderate or severe WMD), 209 (15%) developed dementia. Hospitalisation during follow-up occurred in 891 (65%) patients of whom 103 (12%) had at least one delirium episode and 236 (26%) had at least one infection episode. Hospitalisation without delirium or infection did not predict subsequent dementia (HR 1·01, 95% CI 0·86-1·20). In contrast, hospitalisation with delirium predicted subsequent dementia independently of infection in patients with and without WMD (2·64, 1·47-4·74; p=0·0013 vs 3·41, 1·91-6·09; p<0·0001) especially in those with unimpaired baseline cognition (cognitive test score above cutoff; 4·01, 2·23-7·19 vs 3·94, 1·95-7·93; both p≤0·0001). However, hospitalisation with infection only predicted dementia in those with moderate or severe WMD (1·75, 1·04-2·94 vs 0·68, 0·39-1·20; pdiff=0·023).

INTERPRETATION

The increased risk of dementia after delirium is unrelated to the presence of WMD, whereas infection increases risk only in patients with WMD, suggesting differences in underlying mechanisms and in potential preventive strategies.

FUNDING

National Institute for Health and Care Research and Wellcome Trust.

Assessing patterns of delirium symptoms reveals a novel subtype among elective surgical patients with postoperative delirium

OBJECTIVES

Prior studies reported incidence of hypoactive and hyperactive subtypes of postoperative delirium, but did not consider cognitive symptoms of delirium which are highlighted in the DSM-5 criteria for delirium. This study aims to address this gap in the literature by classifying cases of delirium according to their constellation of cognitive and motoric symptoms of delirium using a statistical technique called Latent Class Analysis (LCA).

METHODS

Data were from five independent study cohorts (N = 1968) of patients who underwent elective spine, knee/hip, or elective gastrointestinal and thoracic procedures, between 2001 and 2017. Assessments of delirium symptoms were conducted using the long form of the Confusion Assessment Method (CAM) pre- and post-surgery. Latent class analyses of CAM data from the first 2 days after surgery were conducted to determine subtypes of delirium based on patterns of cognitive and motoric symptoms of delirium. We also determined perioperative patient characteristics associated with each latent class of delirium and assessed whether the length of delirium for each of the patterns of delirium symptoms identified by the latent class analysis.

RESULTS

The latent class model from postoperative day 1 revealed three distinct patterns of delirium symptoms. One pattern of symptoms, denoted as the Hyperalert class, included patients whose predominant symptoms were being hyperalert or overly sensitive to environmental stimuli and having a low level of motor activity. Another pattern of symptoms, denoted as the Hypoalert class, included patients whose predominant symptom was being hypoalert (lethargic or drowsy). A third pattern of symptoms, denoted as the Cognitive Changes class, included patients who experienced new onset of disorganized thinking, memory impairment, and disorientation. Among 352 patients who met CAM criteria for delirium on postoperative day 1, 34% had symptoms that fit within the Hyperalert latent class, 39% had symptoms that fit within the Hypoalert latent class, and 27% had symptoms that fit within the Cognitive Changes latent class. Similar findings were found when latent class analysis was applied to those who met CAM criteria for delirium on postoperative day 2. Multinomial regression analyses revealed that ASA class, surgery type, and preoperative cognitive status as measured by the Telephone Interview for Cognitive Status (TICS) scores were associated with class membership. Length of delirium differed between the latent classes with the Cognitive Changes latent class having a longer duration compared to the other two classes.

CONCLUSIONS

Older elective surgery patients who did not have acute events or illnesses or a diagnosis of dementia prior to surgery displayed varying symptoms of delirium after surgery. Compared to prior studies that described hypoactive and hyperactive subtypes of delirium, we identified a novel subtype of delirium that reflects cognitive symptoms of delirium. The three subtypes of delirium reveal distinct patterns of delirium symptoms which provide insight into varying risks and care needs of patients with delirium, indicating the necessity of future research on reducing risk for cognitive symptoms of delirium.

Risk factors for dementia in older intensive care unit (ICU) survivors

INTRODUCTION

As the number of older intensive care unit (ICU) survivors grows, there is an urgent need to identify modifiable risk factors for post-ICU dementia.

METHODS

We performed a secondary data analysis of 3144 ICU patients ≥ 50 years of age without a history of dementia or severe mental illness who were screened as part of the Pharmacological Management of Delirium (PMD) study. Delirium was assessed using the Confusion Assessment Method for the ICU. Dementia was identified using International Classification of Diseases Ninth and Tenth revision codes for dementia or prescription of anti-dementia medication.

RESULTS

Average age (standard deviation) was 65.2 ± 9.5 years; 50.4% were female; and 37.3% were Black. Analyses identified stroke (adjusted hazard ratio [HR] 2.49; 95% confidence interval [CI: 1.52, 4.07], P < 0.001), and depression (adjusted HR 3.03; 95% CI [1.80, 5.10], P < 0.001) as post-ICU risk factors for dementia.

DISCUSSION

Future studies will need to examine whether interventions targeting post-ICU stroke and depression can lower dementia incidence in ICU survivors.

HIGHLIGHTS

Risk factors for post-intensive care unit (ICU) dementia were distinct from those of Alzheimer's disease. Cardiovascular risk factors were not associated with dementia in older ICU survivors. Post-ICU stroke was associated with a higher risk of dementia in older ICU survivors. Post-ICU depression was associated with a higher risk of dementia in older ICU survivors.

Biomarkers of neurodegeneration and neural injury as potential predictors for delirium

OBJECTIVES

Determine if biomarkers of Alzheimer's disease and neural injury may play a role in the prediction of delirium risk.

METHODS

In a cohort of older adults who underwent elective surgery, delirium case-no delirium control pairs (N = 70, or 35 matched pairs) were matched by age, sex and vascular comorbidities. Biomarkers from CSF and plasma samples collected prior to surgery, including amyloid beta (Aβ)42 , Aβ40 , total (t)-Tau, phosphorylated (p)-Tau181 , neurofilament-light (NfL), and glial fibrillary acid protein (GFAP) were measured in cerebrospinal fluid (CSF) and plasma using sandwich enzyme-linked immunosorbent assays (ELISAs) or ultrasensitive single molecule array (Simoa) immunoassays.

RESULTS

Plasma GFAP correlated significantly with CSF GFAP and both plasma and CSF GFAP values were nearly two-fold higher in delirium cases. The median paired difference between delirium case and control without delirium for plasma GFAP was not significant (p = 0.074) but higher levels were associated with a greater risk for delirium (odds ratio 1.52, 95% confidence interval 0.85, 2.72 per standard deviation increase in plasma GFAP concentration) in this small study. No matched pair differences or associations with delirium were observed for NfL, p-Tau 181, Aβ40 and Aβ42 .

CONCLUSIONS

These preliminary findings suggest that plasma GFAP, a marker of astroglial activation, may be worth further investigation as a predictive risk marker for delirium.

The frail patient undergoing cardiac surgery: lessons learned and future perspectives

Frailty is a geriatric condition characterized by the reduction of the individual's homeostatic reserves. It determines an increased vulnerability to endogenous and exogenous stressors and can lead to poor outcomes. It is an emerging concept in perioperative medicine, since an increasing number of patients undergoing surgical interventions are older and the traditional models of care seem to be inadequate to satisfy these patients' emerging clinical needs. Nowadays, the progressive technical and clinical improvements allow to offer cardiac operations to an older, sicker and frail population. For these reasons, a multidisciplinary team involving cardiac surgeons, clinical cardiologists, anesthesiologists, and geriatricians, is often needed to assess, select and provide tailored care to these high-risk frail patients to optimize clinical outcomes. There is unanimous agreement that frailty assessment may capture the individual's biological decline and the heterogeneity in risk profile for poor health-related outcomes among people of the same age. However, since commonly used preoperative scores for cardiac surgery fail to capture frailty, a specific preoperative assessment with dedicated tools is warranted to correctly recognize, measure and quantify frailty in these patients. On the contrary, pre-operative and post-operative interventions can reduce the risk of complications and support patient recovery promoting surgical resilience. Minimally invasive cardiac procedures aim to reduce surgical trauma and may be associated with better clinical outcome in this specific sub-group of high-risk patients. Among postoperative adverse events, the occurrence of delirium represents a risk factor for several unfavorable outcomes including mortality and subsequent cognitive decline. Its presence should be carefully recognized, triggering an adequate, evidence based, treatment. There is evidence, from several cross-section and longitudinal studies, that frailty and delirium may frequently overlap, with frailty serving both as a predisposing factor and as an outcome of delirium and delirium being a marker of a latent condition of frailty. In conclusion, frail patients are at increased risk to experience poor outcome after cardiac surgery. A multidisciplinary approach aimed to recognize more vulnerable individuals, optimize pre-operative conditions, reduce surgical invasivity and improve post-operative recovery is required to obtain optimal long-term outcome.

Presence of Preoperative Neurodegeneration Biofluid Markers in Patients with Postoperative Delirium

BACKGROUND

The pathophysiology of delirium is incompletely understood, including what molecular pathways are involved in brain vulnerability to delirium. This study examined whether preoperative plasma neurodegeneration markers were elevated in patients who subsequently developed postoperative delirium through a retrospective case-control study.

METHODS

Inclusion criteria were patients of 65 yr of age or older, undergoing elective noncardiac surgery with a hospital stay of 2 days or more. Concentrations of preoperative plasma P-Tau181, neurofilament light chain, amyloid β1-42 (Aβ42), and glial fibrillary acidic protein were measured with a digital immunoassay platform. The primary outcome was postoperative delirium measured by the Confusion Assessment Method. The study included propensity score matching by age and sex with nearest neighbor, such that each patient in the delirium group was matched by age and sex with a patient in the no-delirium group.

RESULTS

The initial cohort consists of 189 patients with no delirium and 102 patients who developed postoperative delirium. Of 291 patients aged 72.5 ± 5.8 yr, 50.5% were women, and 102 (35%) developed postoperative delirium. The final cohort in the analysis consisted of a no-delirium group (n = 102) and a delirium group (n = 102) matched by age and sex using the propensity score method. Of the four biomarkers assayed, the median value for neurofilament light chain was 32.05 pg/ml for the delirium group versus 23.7 pg/ml in the no-delirium group. The distribution of biomarker values significantly differed between the delirium and no-delirium groups (P = 0.02 by the Kolmogorov-Smirnov test) with the largest cumulative probability difference appearing at the biomarker value of 32.05 pg/ml.

CONCLUSIONS

These results suggest that patients who subsequently developed delirium are more likely to be experiencing clinically silent neurodegenerative changes before surgery, reflected by changes in plasma neurofilament light chain biomarker concentrations, which may identify individuals with a preoperative vulnerability to subsequent cognitive decline.

EDITOR’S PERSPECTIVE

Causal relationships between delirium and Alzheimer's disease: a bidirectional two-sample Mendelian randomization study

BACKGROUND

Previous observational studies have reported that delirium has an association with an increased risk of Alzheimer's disease (AD), and that patients with AD have a higher risk of developing delirium. However, due to the limitations of observational study, it is challenging to confirm whether delirium has a causal effect on AD or reverse causation exists.

METHODS

A bidirectional two-sample Mendelian randomization (MR) was performed to investigate the relationship between delirium and AD. Summary statistics from genome-wide association studies of delirium and AD phenotypes were utilized. Inverse-variance weighted (IVW) method was used as the main analysis approach, and additional analyses were performed using MR Egger, weighted median, simple mode and weighted mode to ensure result accuracy. Heterogeneity and horizontal pleiotropy were assessed using Cochran's Q statistics and MR Egger intercept, separately.

RESULTS

The MR analyses showed that genetically predicted delirium was not associated with AD (IVW: odds ratio [OR] 0.98, 95% CI 0.91-1.05, P = 0.544; MR Egger: OR 0.98, 95% CI 0.83-1.15, P = 0.780; weighted median: OR 0.96, 95% CI 0.88-1.05, P = 0.323; simple mode: OR 0.91, 95% CI 0.80-1.04, P = 0.212; weighted mode: OR 0.93, 95% CI 0.83-1.05, P = 0.277). However, in the reverse direction, AD was associated with delirium (IVW: OR 1.32, 95% CI 1.13-1.54, P = 3.91E-04; MR Egger: OR 1.42, 95% CI 1.02-1.98, P = 5.60E-02; Weighted median: OR 1.39, 95% CI 1.18-1.63, P = 8.22E-05; Simple mode: OR 1.41, 95% CI 1.10-1.80, P = 1.41E-02; Weighted mode: OR 1.39, 95% CI 1.16-1.67, P = 3.23E-03).

CONCLUSION

Based on the results of our MR study, there is no bidirectional causality between delirium and AD, delirium is not associated with an increased risk of AD, while genetically predicted AD is a potential causal risk factor for delirium.

Insights into the pathological basis of dementia from population-based neuropathology studies

The epidemiological neuropathology perspective of population and community-based studies allows unbiased assessment of the prevalence of various pathologies and their relationships to late-life dementia. In addition, this approach provides complementary insights to conventional case-control studies, which tend to be more representative of a younger clinical cohort. The Cognitive Function and Ageing Study (CFAS) is a longitudinal study of cognitive impairment and frailty in the general United Kingdom population. In this review, we provide an overview of the major findings from CFAS, alongside other studies, which have demonstrated a high prevalence of pathology in the ageing brain, particularly Alzheimer's disease neuropathological change and vascular pathology. Increasing burdens of these pathologies are the major correlates of dementia, especially neurofibrillary tangles, but there is substantial overlap in pathology between those with and without dementia, particularly at intermediate burdens of pathology and also at the oldest ages. Furthermore, additional pathologies such as limbic-predominant age-related TDP-43 encephalopathy, ageing-related tau astrogliopathy and primary age-related tauopathies contribute to late-life dementia. Findings from ageing population-representative studies have implications for the understanding of dementia pathology in the community. The high prevalence of pathology and variable relationship to dementia status has implications for disease definition and indicate a role for modulating factors on cognitive outcome. The complexity of late-life dementia, with mixed pathologies, indicates a need for a better understanding of these processes across the life-course to direct the best research for reducing risk in later life of avoidable clinical dementia syndromes.

Scopolamine causes delirium-like brain network dysfunction and reversible cognitive impairment without neuronal loss

Delirium is a severe acute neuropsychiatric syndrome that commonly occurs in the elderly and is considered an independent risk factor for later dementia. However, given its inherent complexity, few animal models of delirium have been established and the mechanism underlying the onset of delirium remains elusive. Here, we conducted a comparison of three mouse models of delirium induced by clinically relevant risk factors, including anesthesia with surgery (AS), systemic inflammation, and neurotransmission modulation. We found that both bacterial lipopolysaccharide (LPS) and cholinergic receptor antagonist scopolamine (Scop) induction reduced neuronal activities in the delirium-related brain network, with the latter presenting a similar pattern of reduction as found in delirium patients. Consistently, Scop injection resulted in reversible cognitive impairment with hyperactive behavior. No loss of cholinergic neurons was found with treatment, but hippocampal synaptic functions were affected. These findings provide further clues regarding the mechanism underlying delirium onset and demonstrate the successful application of the Scop injection model in mimicking delirium-like phenotypes in mice.

Identifying hormones and other perioperative risk factors for postoperative delirium after endoscope-assisted transsphenoidal pituitary adenoma resection: A retrospective, matched cohort study

OBJECTIVE

As a complex and acute brain dysfunction, if postoperative delirium (POD) occurs in the postoperative period, it will lead to a prolonged length of stay in the critical care unit, with increased hospitalization costs and higher mortality. A few case reports inspired us to pay close attention to pituitary tumor-associated delirium. We hypothesized that the changes in hormone levels after pituitary tumor resection might be associated with POD occurrence.

METHODS

Retrospective analysis was performed on data from a single-center cohort study conducted at Southwest Hospital between January 2018 and May 2022. A total of 360 patients with pituitary tumors who underwent endoscope-assisted transsphenoidal pituitary tumor resection were divided into two groups at a 1:3 ratio, with 36 patients in the POD group and 108 patients in the non-POD group matched by propensity score, age, sex, and tumor size. Basic characteristics, pituitary adenoma features, endocrine levels and other biochemical indicators, and Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) for postoperative delirium were documented for further analysis.

RESULTS

Lower insulin-like growth factor-1 (IGF-1, p = .024) and corticotropin-releasing hormone (CRH, p = .005) levels were closely associated with postoperative delirium and with high levels of blood glucose (GLU, p = .023) after surgery. Subsequent analysis indicated that serum potassium (OR: 0.311, 95% CI 0.103-0.935), sodium (OR: 0.991, 95% CI 0.983-1.000), CRH (OR: 0.964, 95% CI 0.936-0.994), and GLU (OR: 1.654, 95% CI 1.137-2.406) levels in the perioperative period were independent risk factors for delirium.

CONCLUSIONS

Our study indicated that lower serum CRH, potassium, sodium, and GLU levels may be associated with the occurrence of POD after endoscopic-assisted transsphenoidal surgery. These data provide preliminary evidence for the management of POD in pituitary adenoma patients after surgery. Further studies are needed to identify pharmacological and nonpharmacological multicomponent treatment strategies.

Donepezil treatment is associated with improved outcomes in critically ill dementia patients via a reduction in delirium

INTRODUCTION

During hospital admissions, patients with dementia are at risk for developing delirium, an acute state of brain failure associated with significant morbidity. There are currently no pharmacologic tools to treat or prevent delirium. Decreased cholinergic signaling plays a role in the pathophysiology of both disorders. Whether enhanced pre-hospital cholinergic signaling in patients with dementia improves outcomes during critical illness remains unknown.

METHODS

We utilized the Medical Information Mart for Intensive Care III (MIMIC-III) database to determine whether pre-hospital donepezil use was associated with improved outcomes during critical illness in dementia patients.

RESULTS

We identified 2734 subjects with dementia admitted to the intensive care unit (ICU; 447 received donepezil). After adjusting for confounders, patients with dementia who were receiving donepezil had a significantly reduced in-hospital and 90-day mortality, ICU length of stay, and duration of mechanical ventilation. Donepezil use was associated with, and its benefit was mediated by, reduced delirium.

DISCUSSION

Patients with dementia who are treated with donepezil have improved outcomes during critical illness and reductions in delirium.

HIGHLIGHTS

No pharmacologic treatments exist to reduce delirium in patients with dementia. Donepezil improves outcomes during critical illness in patients with dementia. Improved outcomes are mediated by a reduction in hospital delirium. Future studies in patients with dementia should prospectively evaluate donepezil in the prevention of delirium.

Caregivers’ experience with Tele-Savvy Caregiver Program post-hospitalization

Despite the frequent hospitalizations and readmissions of persons living with dementia (PLWD), no telehealth transitional care interventions focus on PLWDs' unpaid caregivers. Tele-Savvy Caregiver Program is a 43-day evidence-based online psychoeducational intervention for PLWDs' caregivers. The aim of this formative evaluation was to explore caregivers' acceptability of and experience with their participation in Tele-Savvy after their PLWDs' hospital discharge. Additionally, we gathered caregivers' feedback on the recommended features of a transitional care intervention, suitable for caregivers' schedule and needs post-discharge. Fifteen caregivers completed the interviews. Data were analyzed via conventional content analysis. Four categories were identified: (1) Tele-Savvy improved participants' understanding of dementia and caregiving; (2) hospitalization started a "new level of normal"; (3) PLWDs' health concerns; and (4) transitional care intervention development. Participation in Tele-Savvy was acceptable for most caregivers. Participants' feedback provides content and structural guidance for the development of a new transitional care intervention for PLWDs' caregivers.

Altered Tryptophan-Kynurenine Pathway in Delirium: A Review of the Current Literature

Delirium, a common form of acute brain dysfunction, is associated with increased morbidity and mortality, especially in older patients. The underlying pathophysiology of delirium is not clearly understood, but acute systemic inflammation is known to drive delirium in cases of acute illnesses, such as sepsis, trauma, and surgery. Based on psychomotor presentations, delirium has three main subtypes, such as hypoactive, hyperactive, and mixed subtype. There are similarities in the initial presentation of delirium with depression and dementia, especially in the hypoactive subtype. Hence, patients with hypoactive delirium are frequently misdiagnosed. The altered kynurenine pathway (KP) is a promising molecular pathway implicated in the pathogenesis of delirium. The KP is highly regulated in the immune system and influences neurological functions. The activation of indoleamine 2,3-dioxygenase, and specific KP neuroactive metabolites, such as quinolinic acid and kynurenic acid, could play a role in the event of delirium. Here, we collectively describe the roles of the KP and speculate on its relevance in delirium.

POSTOPED: improving surveillance of postoperative delirium in a Scottish tertiary hospital

Delirium is the most common postoperative complication among patients over the age of 65 years. It is associated with increased morbidity and is a significant financial cost to healthcare systems.We aimed to improve the detection of delirium on the surgical wards of a tertiary surgical centre. This would take the form of completion of 4AT assessments (the 4 AT test for delirium, on admission and 1 day postoperatively). Prior to this project, the 4AT was in use in the surgical admission clerking paperwork for over 65 s, however, 4AT assessments were not routinely performed as part of day 1 postoperative assessment. By introducing routine postoperative assessment and reinforcing the importance of admission assessment, we hoped to allow for objective comparisons to be made about patients cognitive state and thereafter improve delirium identification.After a baseline snapshot data collection period, we conducted five (Plan, Do, Study, Act) cycles following which repeat snapshot data were collected. Improvement strategies included 'tea-trolley' teaching sessions, adhesive 4AT pro-forma, targeted accompaniment of specialty ward rounds with reminders to complete 4AT assessments and working with nursing staff to promote awareness of delirium among permanent non-rotating healthcare professionals.For the admission 4ATs, completion improved from a baseline of 74.1%-90.5% in cycle 5. Completion of postoperative 4AT assessments rose from 14.8% at baseline to 47.6% in cycle 5.We were able to improve the use of a delirium screening tool, (the 4AT) among the postoperative elderly population in this centre via the use of regular teaching sessions, targeted interventions on ward rounds as well working with non-rotating staff. Further improvements could be made by widening access to delirium champion programmes and including delirium as an outcome measure of national surgical audits such as the National Emergency Laparotomy Audit.

Risk factors for delirium in advanced cancer patients: A systematic review and meta-analysis

PURPOSE

To systematically collect published research in order to identify and quantify risk factors for delirium in advanced cancer patients.

METHODS

The Cochrane Library, PubMed, Proquest, CINAHL, Web of Science, Ovid MEDLINE, Embase, Scopus, Chinese Wanfang Data, Chinese Periodical Full-text Database (VIP), Chinese Biomedical Literature Database (CBM), and Chinese National Knowledge Infrastructure (CNKI) were systematically searched for cohort or case-control studies reporting individual risk factors for delirium among advanced-stage cancer patients published prior to March 2022. The Newcastle-Ottawa Scale was used to assess the methodological quality of included studies. The pooled adjusted odds ratio (aOR) and its 95% confidence interval were calculated using the RevMan 5.4 software package.

RESULTS

A total of 15 studies with data from 3106 advanced cancer patients were included in our analysis. Nine studies were high-quality and six were of moderate quality. Pooled analyses revealed that 11 risk factors were statistically significant. High-intensity risk factors included sleep disturbance, infection, cachexia and the Palliative Prognostic Index; medium-intensity risk factors included male sex, renal failure, dehydration and drowsiness; low-intensity risk factors included age, total bilirubin and opioid use. Antibiotic use was found to have been a protective factor.

CONCLUSIONS

We identified 12 independent risk factors that were significantly associated with delirium in advanced cancer patients and provide an evidence-based foundation to implement appropriate preventive strategies.

Cerebrospinal fluid quinolinic acid is strongly associated with delirium and mortality in hip-fracture patients

BACKGROUNDThe kynurenine pathway (KP) has been identified as a potential mediator linking acute illness to cognitive dysfunction by generating neuroactive metabolites in response to inflammation. Delirium (acute confusion) is a common complication of acute illness and is associated with increased risk of dementia and mortality. However, the molecular mechanisms underlying delirium, particularly in relation to the KP, remain elusive.METHODSWe undertook a multicenter observational study with 586 hospitalized patients (248 with delirium) and investigated associations between delirium and KP metabolites measured in cerebrospinal fluid (CSF) and serum by targeted metabolomics. We also explored associations between KP metabolites and markers of neuronal damage and 1-year mortality.RESULTSIn delirium, we found concentrations of the neurotoxic metabolite quinolinic acid in CSF (CSF-QA) (OR 2.26 [1.78, 2.87], P < 0.001) to be increased and also found increases in several other KP metabolites in serum and CSF. In addition, CSF-QA was associated with the neuronal damage marker neurofilament light chain (NfL) (β 0.43, P < 0.001) and was a strong predictor of 1-year mortality (HR 4.35 [2.93, 6.45] for CSF-QA ≥ 100 nmol/L, P < 0.001). The associations between CSF-QA and delirium, neuronal damage, and mortality remained highly significant following adjustment for confounders and multiple comparisons.CONCLUSIONOur data identified how systemic inflammation, neurotoxicity, and delirium are strongly linked via the KP and should inform future delirium prevention and treatment clinical trials that target enzymes of the KP.FUNDINGNorwegian Health Association and South-Eastern Norway Regional Health Authorities.

Delirium in older hospitalized patients-A prospective analysis of the detailed course of delirium in geriatric inpatients

BACKGROUND

Delirium in older hospitalized patients (> 65) is a common clinical syndrome, which is frequently unrecognized.

AIMS

We aimed to describe the detailed clinical course of delirium and related cognitive functioning in geriatric patients in a mainly non-postoperative setting in association with demographic and clinical parameters and additionally to identify risk factors for delirium in this common setting.

METHODS

Inpatients of a geriatric ward were screened for delirium and in the case of presence of delirium included into the study. Patients received three assessments including Mini-Mental-Status-Examination (MMSE) and the Delirium Rating Scale Revised 98 (DRS-R-98). We conducted correlation and linear mixed-effects model analyses to detect associations.

RESULTS

Overall 31 patients (82 years (mean)) met the criteria for delirium and were included in the prospective observational study. Within one week of treatment, mean delirium symptom severity fell below the predefined cut-off. While overall cognitive functioning improved over time, short- and long-term memory deficits remained. Neuroradiological conspicuities were associated with cognitive deficits, but not with delirium severity.

DISCUSSION

The temporal stability of some delirium symptoms (short-/long-term memory, language) on the one hand and on the other hand decrease in others (hallucinations, orientation) shown in our study visualizes the heterogeneity of symptoms attributed to delirium and their different courses, which complicates the differentiation between delirium and a preexisting cognitive decline. The recovery from delirium seems to be independent of preclinical cognitive status.

CONCLUSION

Treatment of the acute medical condition is associated with a fast decrease in delirium severity. Given the high incidence and prevalence of delirium in hospitalized older patients and its detrimental impact on cognition, abilities and personal independence further research needs to be done.

Regional cerebral hypometabolism on 18F-FDG PET/CT scan in delirium is independent of acute illness and dementia

INTRODUCTION

Delirium is associated with new onset dementia and accelerated cognitive decline; however, its pathophysiology remains unknown. Cerebral glucose metabolism previously seen in delirium may have been attributable to acute illness and/or dementia. We aimed to statistically map cerebral glucose metabolism attributable to delirium.

METHODS

We assessed cerebral glucose metabolism using ¹⁸ F-fluorodeoxyglucose positron emission tomography (FDG-PET) in sick, older patients with and without delirium, all without clinical dementia (N = 20). Strict exclusion criteria were adopted to minimize the effect of established confounders on FDG-PET.

RESULTS

Patients with delirium demonstrated hypometabolism in the bilateral thalami and right superior frontal, right posterior cingulate, right infero-lateral anterior temporal, and left superior parietal cortices. Regional hypometabolism correlated with delirium severity and performance on neuropsychological testing.

DISCUSSION

In patients with acute illness but without clinical dementia, delirium is accompanied by regional cerebral hypometabolism. While some hypometabolic regions may represent preclinical Alzheimer's disease (AD), thalamic hypometabolism is atypical of AD and consistent with the clinical features that are unique to delirium.

Three key areas in progressing delirium practice and knowledge: recognition and relief of distress, new directions in delirium epidemiology and developing better research assessments

Delirium presents formidable challenges: it affects one in four of older hospitalised adults, greatly elevates the risk of multiple short- and long-term complications including dementia and causes significant distress. Delirium care remains generally poor. Yet, there are clear grounds for optimism; the last decade has seen impactful policy advances and a tripling of research output. Here, we highlight three linked areas which have strong potential to transform delirium practice and knowledge in the near term. Delirium-related distress is strikingly underrepresented in practice guidance and research. Proactive recognition combined with effective clinical responses based on good communication provides a critical and largely untapped opportunity to improve care. Delirium epidemiology research is well positioned to produce novel insights through advanced prospective designs in populations such as emergency medical patients with detailed pre-, intra- and post-delirium assessments allied with fluid, imaging and other biomarkers. Research-grade assessment of delirium currently involves a chaotic array of tools, methods and diagnostic algorithms. Areas for development: expand and analytically distinguish the range of features assessed (including distress), optimise feature assessment including use of validated neuropsychological tests where possible, produce standardised algorithms which articulate explicit pathways from features to diagnosis, and create new fine-grained approaches to the measurement of severity. Delirium practice and knowledge show accelerating growth. This is encouraging but much of the necessary progress is still to come. Innovation in these three highlighted areas, as well as many others, will open up exciting possibilities in enhancing the care of patients with this common and often devastating condition.

Inflammatory and blood gas markers of COVID-19 delirium compared to non-COVID-19 delirium: a cross-sectional study

OBJECTIVES

We aimed to find the association of inflammation and respiratory failure with delirium in COVID-19 patients. We compare the inflammatory and arterial blood gas markers between patients with COVID-19 delirium and delirium in other medical disorders.

METHODS

This cross-sectional study used the CHART-DEL, a validated research tool, to screen patients for delirium retrospectively from clinical notes. Inflammatory markers C-reactive protein (CRP) and white cell count (WBC), and the partial pressures of oxygen (PO₂) and carbon dioxide (PCO₂) were compared between patients with COVID-19 delirium and delirium in other medical disorders.

RESULTS

In bivariate analysis, CRP (mg/L) was significantly higher in the COVID-19 group, (81.7 ± 80.0 vs. 58.8 ± 87.7, p = 0.04), and WBC (10⁹/L) was significantly lower (7.44 ± 3.42 vs. 9.71 ± 5.45, p = 0.04). The geometric mean of CRP in the COVID-19 group was 140% higher in multiple linear regression (95% CI = 7-439%, p = 0.03) with age and sex as covariates. There were no significant differences in pO₂ or pCO₂ across groups.

CONCLUSION

The association between higher CRP and COVID-19 in patients with delirium may suggest an inflammatory basis for delirium in COVID-19. Our findings may assist clinicians in establishing whether delirium is due to COVID-19, which may improve management and outcomes of infected patients.

The inter-relationship between delirium and dementia: the importance of delirium prevention

Delirium and dementia are two frequent causes of cognitive impairment among older adults and have a distinct, complex and interconnected relationship. Delirium is an acute confusional state characterized by inattention, cognitive dysfunction and an altered level of consciousness, whereas dementia is an insidious, chronic and progressive loss of a previously acquired cognitive ability. People with dementia have a higher risk of developing delirium than the general population, and the occurrence of delirium is an independent risk factor for subsequent development of dementia. Furthermore, delirium in individuals with dementia can accelerate the trajectory of the underlying cognitive decline. Delirium prevention strategies can reduce the incidence of delirium and associated adverse outcomes, including falls and functional decline. Therefore, delirium might represent a modifiable risk factor for dementia, and interventions that prevent or minimize delirium might also reduce or prevent long-term cognitive impairment. Additionally, understanding the pathophysiology of delirium and the connection between delirium and dementia might ultimately lead to additional treatments for both conditions. In this Review, we explore mechanisms that might be common to both delirium and dementia by reviewing evidence on shared biomarkers, and we discuss the importance of delirium recognition and prevention in people with dementia.

In this Review, Fong and Inouye explore mechanisms that might be common to both delirium and dementia. They present delirium as a possible modifiable risk factor for dementia and discuss the importance of delirium prevention strategies in reducing this risk.

Delirium and dementia are frequent causes of cognitive impairment among older adults and have a distinct, complex and interconnected relationship.

Delirium prevention strategies have been shown to reduce not only the incidence of delirium but also the incidence of adverse outcomes associated with delirium such as falls and functional decline.

Adverse outcomes associated with delirium, such as the onset of dementia symptoms in individuals with preclinical dementia, and/or the acceleration of cognitive decline in individuals with dementia might also be delayed by the implementation of delirium prevention strategies.

Evidence regarding the association of systemic inflammatory and neuroinflammatory biomarkers with delirium is variable, possibly as a result of co-occurring dementia pathology or disruption of the blood–brain barrier.

Alzheimer disease pathology, even prior to the onset of symptoms, might have an effect on delirium risk, with potential mechanisms including neuroinflammation and gene–protein interactions with the APOE ε4 allele.

Novel strategies, including proteomics, multi-omics, neuroimaging, transcranial magnetic stimulation and EEG, are beginning to reveal how changes in cerebral blood flow, spectral power and connectivity can be associated with delirium; further work is needed to expand these findings to patients with delirium superimposed upon dementia.

Proposing a Scientific and Technological Approach to the Summaries of Clinical Issues of Inpatient Elderly with Delirium: A Viewpoint

Background/rationale: Despite mounting evidence about delirium, this complex geriatric syndrome is still not well managed in clinical contexts. The aging population creates a very demanding area for innovation and technology in healthcare. For instance, an outline of an aging-friendly healthcare environment and clear guidance for technology-supported improvements for people at delirium risk are lacking. Objective: We aimed to foster debate about the importance of technical support in optimizing healthcare professional practice and improving the outcomes for inpatients’ at delirium risk. We focused on critical clinical points in the field of delirium worthy of being addressed by a multidisciplinary approach. Methods: Starting from a consensus workshop sponsored by the Management Perfectioning Course based at the Marco Biagi Foundation (Modena, Italy) about clinical issues related to delirium management still not addressed in our healthcare organizations, we developed a requirements’ analysis among the representatives of different disciplines and tried to formulate how technology could support the summaries of the clinical issues. We analyzed the national and international panorama by a PubMed consultation of articles with the following keywords in advanced research: “delirium”, “delirium management”, “technology in healthcare”, and “elderly population”. Results: Despite international recommendations, delirium remains underdiagnosed, underdetected, underreported, and mismanaged in the acute hospital, increasing healthcare costs, healthcare professionals’ job distress, and poor clinical outcomes. Discussion: Although all healthcare professionals recognize delirium as a severe and potentially preventable source of morbidity and mortality for hospitalized older people, it receives insufficient attention in resource allocation and multidisciplinary research. We synthesized how tech-based tools could offer potential solutions to the critical clinical points in delirium management.

Functional decline, long term symptoms and course of frailty at 3-months follow-up in COVID-19 older survivors, a prospective observational cohort study

BACKGROUND

Aging is one of the most important prognostic factors increasing the risk of clinical severity and mortality of COVID-19 infection. However, among patients over 75 years, little is known about post-acute functional decline.

OBJECTIVE

The aim of this study was to identify factors associated with functional decline 3 months after COVID-19 onset, to identify long term COVID-19 symptoms and transitions between frailty statesafter COVID-19 onset in older hospitalized patients.

METHODS

This prospective observational study included COVID-19 patients consecutively hospitalized from March to December 2020 in Acute Geriatric Ward in Nantes University Hospital. Functional decline, frailty status and long term symptoms were assessed at 3 month follow up. Functional status was assessed using the Activities of Daily Living simplified scale (ADL). Frailty status was evaluated using Clinical Frailty Scale (CFS). We performed multivariable analyses to identify factors associated with functional decline.

RESULTS

Among the 318 patients hospitalized for COVID-19 infection, 198 were alive 3 months after discharge. At 3 months, functional decline occurred in 69 (36%) patients. In multivariable analysis, a significant association was found between functional decline and stroke (OR = 4,57, p = 0,003), history of depressive disorder (OR = 3,05, p = 0,016), complications (OR = 2,24, p = 0,039), length of stay (OR = 1,05, p = 0,025) and age (OR = 1,08, p = 0,028). At 3 months, 75 patients described long-term symptoms (49.0%). Of those with frailty (CFS scores ≥5) at 3-months follow-up, 30% were not frail at baseline. Increasing frailty defined by a worse CFS state between baseline and 3 months occurred in 41 patients (26.8%).

CONCLUSIONS

This study provides evidence that both the severity of the COVID-19 infection and preexisting medical conditions correlates with a functional decline at distance of the infection. This encourages practitioners to establish discharge personalized care plan based on a multidimensional geriatric assessment and in parallel on clinical severity evaluation.

Alpha-2-adrenergic receptor agonists for the prevention of delirium and cognitive decline after open heart surgery (ALPHA2PREVENT): protocol for a multicentre randomised controlled trial

INTRODUCTION

Postoperative delirium is common in older cardiac surgery patients and associated with negative short-term and long-term outcomes. The alpha-2-adrenergic receptor agonist dexmedetomidine shows promise as prophylaxis and treatment for delirium in intensive care units (ICU) and postoperative settings. Clonidine has similar pharmacological properties and can be administered both parenterally and orally. We aim to study whether repurposing of clonidine can represent a novel treatment option for delirium, and the possible effects of dexmedetomidine and clonidine on long-term cognitive trajectories, motor activity patterns and biomarkers of neuronal injury, and whether these effects are associated with frailty status.

METHODS AND ANALYSIS

This five-centre, double-blind randomised controlled trial will include 900 cardiac surgery patients aged 70+ years. Participants will be randomised 1:1:1 to dexmedetomidine or clonidine or placebo. The study drug will be given as a continuous intravenous infusion from the start of cardiopulmonary bypass, at a rate of 0.4 µg/kg/hour. The infusion rate will be decreased to 0.2 µg/kg/hour postoperatively and be continued until discharge from the ICU or 24 hours postoperatively, whichever happens first.Primary end point is the 7-day cumulative incidence of postoperative delirium (Diagnostic and Statistical Manual of Mental Disorders, fifth edition). Secondary end points include the composite end point of coma, delirium or death, in addition to delirium severity and motor activity patterns, levels of circulating biomarkers of neuronal injury, cognitive function and frailty status 1 and 6 months after surgery.

ETHICS AND DISSEMINATION

This trial is approved by the Regional Committee for Ethics in Medical Research in Norway (South-East Norway) and by the Norwegian Medicines Agency. Dissemination plans include publication in peer-reviewed medical journals and presentation at scientific meetings.

TRIAL REGISTRATION NUMBER

NCT05029050.

The evidence for introducing case-finding for delirium and dementia in older medical inpatients in a New Zealand hospital

OBJECTIVE

The aim of this project was to make the case to the managers of a large urban teaching hospital in New Zealand for the introduction of systematic case-finding for pre-existing cognitive impairment/dementia in older hospital inpatients that screen positive for delirium.

METHOD

Two hundred consecutive acute admissions aged 75+ in four medical wards were assessed using the 4AT assessment tool for delirium and the Alzheimer Questionnaire (AQ) for pre-existing cognitive impairment/dementia. Length of stay and mortality at 1 year were also collected.

RESULTS

Over a third of the sample screened positive for delirium and nearly two-thirds of these also screened positive for dementia. The median length of stay was 5 days for delirium without dementia and 7 days for delirium with dementia, compared to 3 days for those who screened negative for both. After adjustment for age, gender and ethnic group, people who screened positive for delirium (with or without dementia) had 50% longer length of stay (p < 0.05) and at least double the risk of death (p < 0.05).

CONCLUSION

Older hospital inpatients that screen positive for delirium and dementia using 4AT and AQ have longer lengths of stay and higher mortality. Identification may lead to more timely interventions that help to improve health outcomes and reduce hospital costs.

Monocyte NLRP3-IL-1β Hyperactivation Mediates Neuronal and Synaptic Dysfunction in Perioperative Neurocognitive Disorder

Perioperative neurocognitive disorder may develop in vulnerable patients following major operation. While neuroinflammation is linked to the cognitive effects of surgery, how surgery and immune signaling modulate neuronal circuits, leading to learning and memory impairment remains unknown. Using in vivo two-photon microscopy, Ca²⁺ activity and postsynaptic dendritic spines of layer 5 pyramidal neurons in the primary motor cortex of a mouse model of thoracic surgery are imaged. It is found that surgery causes neuronal hypoactivity, impairments in learning-dependent dendritic spine formation, and deficits in multiple learning tasks. These neuronal and synaptic alterations in the cortex are mediated by peripheral monocytes through the NLRP3 inflammasome-dependent IL-1β production. Depleting peripheral monocytes or inactivating NLRP3 inflammasomes before surgery reduces levels of IL-1β and ameliorates neuronal and behavioral deficits in mice. Furthermore, adoptive transfer of IL-1β-producing myeloid cells from mice undertaking thoracic surgery is sufficient to induce neuronal and behavioral deficits in naïve mice. Together, these findings suggest that surgery leads to excessive NLRP3 activation in monocytes and elevated IL-1β signaling, which in turn causes neuronal hypoactivity and perioperative neurocognitive disorder.

Impact of COVID-19 on the Onset and Progression of Alzheimer's Disease and Related Dementias: A Roadmap for Future Research

COVID-19 causes lasting neurological symptoms in some survivors. Like other infections, COVID-19 may increase risk of cognitive impairment. This perspective highlights four knowledge gaps about COVID-19 that need to be filled to avoid this possible health issue. The first is the need to identify the COVID-19 symptoms, genetic polymorphisms and treatment decisions associated with risk of cognitive impairment. The second is the absence of model systems in which to test hypotheses relating infection to cognition. The third is the need for consortia for studying both existing and new longitudinal cohorts in which to monitor long term consequences of COVID-19 infection. A final knowledge gap discussed is the impact of the isolation and lack of social services brought about by quarantine/lockdowns on people living with dementia and their caregivers. Research into these areas may lead to interventions that reduce the overall risk of cognitive decline for COVID-19 survivors.

Music Interventions and Delirium in Adults: A Systematic Literature Review and Meta-Analysis

Delirium is a neuropsychiatric syndrome represented by an acute disturbance in attention, awareness and cognition, highly prevalent in older, and critically ill patients, and associated with poor outcomes. This review synthesized existing evidence on the effectiveness of music interventions on delirium in adults, and music interventions (MIs), psychometric assessments and outcome measures used. We searched MEDLINE, PsychINFO, SCOPUS, Clinical Trials and CENTRAL for quantitative designs comparing any MIs to standard care or another intervention. From 1150 studies 12 met the inclusion criteria, and 6 were included in the meta-analysis. Narrative synthesis showed that most studies focused on prevention, few assessed delirium severity, with the majority of studies reporting beneficial effects. The summary relative risk for incident delirium comparing music vs. no music in postsurgical and critically ill older patients was 0.52 (95% confidential interval (CI): 0.20−1.35, I2 = 79.1%, heterogeneity <0.0001) for the random effects model and 0.47 (95% CI: 0.34−0.66) using the fixed effects model. Music listening interventions were more commonly applied than music therapy delivered by credentialed music therapists, and delirium assessments methods were heterogeneous, including both standardized tools and systematic observations. Better designed studies are needed addressing effectiveness of MIs in specific patient subgroups, exploring the correlations between intervention-types/dosages and delirium symptoms.

Identification of Potential Key circRNAs in Aged Mice With Postoperative Delirium

Postoperative delirium (POD) is a common postoperative complication in elderly patients and seriously affects postoperative recovery. The exact mechanism of POD is still unclear. Therefore, it is necessary to explore the mechanism of POD in transcriptional regulation. At present, circRNAs have been proven to play an important role in a variety of mental health and cognitive disorders, such as Alzheimer’s disease, depression and schizophrenia. To reveal the effect of circRNA on POD, we used microarray to analyze the differential expression profiles of circRNAs in the hippocampus of 12-month-old mice between the tibial fracture and control groups. A total of 1,4236 circRNAs were identified. Compared with the control group, there were 500 circRNAs with increased expression and 187 with decreased expression. The accuracy of the microarray data was further verified by qRT–PCR. Finally, GO enrichment and KEGG pathway analyses indicated that changes in axon orientation, ubiquitin-mediated proteolysis, glutamate synapses, the estrogen signaling pathway, the RAS signaling pathway and other systems may be important potential pathological mechanisms in the progression of POD. In particular, we found that the HOMER1 gene and its transcript mmu_circRNA_26701 are specifically expressed in the glutamate synapse, which may provide new clues and intervention targets for the progression of this refractory disease.

Prevalence and features of delirium in older patients admitted to rehabilitation facilities: a multicenter study

BACKGROUND

Delirium is thought to be common across various settings of care; however, still little research has been conducted in rehabilitation.

AIM

We investigated the prevalence of delirium, its features and motor subtypes in older patients admitted to rehabilitation facilities during the three editions of the "Delirium Day project".

METHODS

We conducted a cross-sectional study in which 1237 older patients (age ≥ 65 years old) admitted to 50 Italian rehabilitation wards during the three editions of the "Delirium Day project" (2015 to 2017) were included. Delirium was evaluated through the 4AT and its motor subtype with the Delirium Motor Subtype Scale.

RESULTS

Delirium was detected in 226 patients (18%), and the most recurrent motor subtype was mixed (37%), followed by hypoactive (26%), hyperactive (21%) and non-motor one (16%). In a multivariate Poisson regression model with robust variance, factors associated with delirium were: disability in basic (PR 1.48, 95%CI: 1.17-1.9, p value 0.001) and instrumental activities of daily living (PR 1.58, 95%CI: 1.08-2.32, p value 0.018), dementia (PR 2.10, 95%CI: 1.62-2.73, p value < 0.0001), typical antipsychotics (PR 1.47, 95%CI: 1.10-1.95, p value 0.008), antidepressants other than selective serotonin reuptake inhibitors (PR 1.3, 95%CI: 1.02-1.66, p value 0.035), and physical restraints (PR 2.37, 95%CI: 1.68-3.36, p value < 0.0001).

CONCLUSION

This multicenter study reports that 2 out 10 patients admitted to rehabilitations had delirium on the index day. Mixed delirium was the most prevalent subtype. Delirium was associated with unmodifiable (dementia, disability) and modifiable (physical restraints, medications) factors. Identification of these factors should prompt specific interventions aimed to prevent or mitigate delirium.

Improving delirium screening in older adults at the Royal United Hospital, Bath

Aims/Background

Delirium affects around 20% of older inpatients, increasing mortality and length of stay. Around 30% of cases are preventable. The authors sought to determine compliance of the admissions to the Older People's Unit of the Royal University Hospital Bath with the national and internal guidelines for delirium screening and improve its use on admission.

Methods

A total of 60 patients' notes were inspected for compliance. Subsequently, the authors implemented teaching, changed the admission proforma and re-wrote the hospital guidelines for delirium. The notes were rescreened at 6 and 18 months.

Results

Initially, 25% of notes met the national standards and 63% met the hospital criteria. At 6 months this was 52% and 82% respectively, and at 18 months it was 41% and 87% respectively. The proportion of patients screened via multiple methods also increased.

Conclusions

There was a sustained improvement in compliance with the national and hospital standards for delirium screening. There was some degradation in the national standard but the proportion of patients meeting the National Institute for Health and Care Excellence standard was still higher than pre-intervention.

The effect of baseline cognition and delirium on long-term cognitive impairment and mortality: a prospective population-based study

Background

There is an unmet public health need to understand better the relationship between baseline cognitive function, the occurrence and severity of delirium, and subsequent cognitive decline. Our aim was to quantify the relationship between baseline cognition and delirium and follow-up cognitive impairment.

Methods

We did a prospective longitudinal study in a stable representative community sample of adults aged 70 years or older who were registered with a Camden-based general practitioner in the London Borough of Camden (London, UK). Participants were recruited by invitation letters from general practice lists or by direct recruitment of patients from memory clinics or patients recently discharged from secondary care. We quantified baseline cognitive function with the modified Telephone Interview for Cognitive Status. In patients who were admitted to hospital, we undertook daily assessments of delirium using the Memorial Delirium Assessment Scale (MDAS). We estimated the association of pre-admission baseline cognitive function with delirium prevalence, severity, and duration. We assessed subsequent cognitive function 2 years after baseline recruitment using the Telephone Interview for Cognitive Status. Regression models were adjusted by age, sex, education, illness severity, and frailty.

Findings

We recruited 1510 participants (median age 77 [IQR 73-82], 57% women) between March, 2017, and October, 2018. 209 participants were admitted to hospital across 371 episodes (1999 person-days of assessment). Better baseline cognition was associated with a lower risk of delirium (odds ratio 0·63, 95% CI 0·45 to 0·89) and with less severe delirium (-1·6 MDAS point, 95% CI -2·6 to -0·7). Individuals with high baseline cognition (baseline Z score +2·0 SD) had demonstrable decline even without delirium (follow-up Z score +1·2 SD). However, those with a high delirium burden had an even larger absolute decline of 2·2 SD in Z score (follow-up Z score -0·2). Once individuals had more than 2 days of moderate delirium, the rates of death over 2 years were similar regardless of baseline cognition; a better baseline cognition no longer conferred any mortality benefit.

Interpretation

A higher baseline cognitive function is associated with a good prognosis with regard to likelihood and severity of delirium. However, those with a high baseline cognition and with delirium had the highest degree of cognitive decline, a change similar to the decline observed in individuals with a high amyloid burden in other cohorts. Older people with a healthy baseline cognitive function who develop delirium stand to lose the most after delirium. This group could benefit from targeted cognitive rehabilitation interventions after delirium.

Inhibition of unfolded protein response prevents post-anesthesia neuronal hyperactivity and synapse loss in aged mice

Delirium is the most common postoperative complication in older patients after prolonged anesthesia and surgery and is associated with accelerated cognitive decline and dementia. The neuronal pathogenesis of postoperative delirium is largely unknown. The unfolded protein response (UPR) is an adaptive reaction of cells to perturbations in endoplasmic reticulum function. Dysregulation of UPR has been implicated in a variety of diseases including Alzheimer's disease and related dementias. However, whether UPR plays a role in anesthesia-induced cognitive impairment remains unexplored. By performing in vivo calcium imaging in the mouse frontal cortex, we showed that exposure of aged mice to the inhalational anesthetic sevoflurane for 2 hours resulted in a marked elevation of neuronal activity during recovery, which lasted for at least 24 hours after the end of exposure. Concomitantly, sevoflurane anesthesia caused a prolonged increase in phosphorylation of PERK and eIF2α, the markers of UPR activation. Genetic deletion or pharmacological inhibition of PERK prevented neuronal hyperactivity and memory impairment induced by sevoflurane. Moreover, we showed that PERK suppression also reversed various molecular and synaptic changes induced by sevoflurane anesthesia, including alterations of synaptic NMDA receptors, tau protein phosphorylation, and dendritic spine loss. Together, these findings suggest that sevoflurane anesthesia causes abnormal UPR in the aged brain, which contributes to neuronal hyperactivity, synapse loss and cognitive decline in aged mice.

Impact of a dementia-friendly program on detection and management of patients with cognitive impairment and delirium in acute-care hospital units: a controlled clinical trial design

Background

Frail older persons with cognitive impairment (CI) are at special risk of experiencing delirium during acute hospitalisation. The purpose of this study was to investigate whether a dementia-friendly hospital program contributes to improved detection and management of patients with CI and risk of delirium at an acute-care hospital in Norway. Furthermore, we aimed to explore whether the program affected the detection of delirium, pharmacological treatment, 30-day re-hospitalisation, 30-day mortality and institutionalisation afterwards.

Methods

This study was part of a larger quality improvement project aiming at developing and implementing a new program for early screening and management of patients with CI. This study, evaluating the program are designed as a controlled clinical trial with a historical control group. It was conducted at two different medical wards at a large acute-care hospital in Norway from September 2018 to December 2019. A total of 423 acute hospitalised patients 75 years of age or older were included in the study. Delirium screening and cognitive tests were recorded by research staff with the 4 ‘A’s Test (4AT) and the Confusion Assessment Measure (CAM), while demographic and medical information was recorded from the electronic medical records (EMR).

Results

Implementation of the dementia-friendly hospital program did not show any significant changes in the identification of patients with CI. However, the share of patients screened with 4AT within 24 h increased from 0% to 35.5% (P < .001). The proportion of the patients with CI identified by the clinical staff, who received measures to promote “dementia-friendly” care and reduce the risk for delirium increased by 32.2% (P < .001), compared to the control group. Furthermore, the number of patients with CI who were prescribed antipsychotic, hypnotic or sedative medications was reduced by 24.5% (P < .001). There were no differences in delirium detection, 30-day readmission or 30-day mortality.

Conclusions

A model for early screening and multifactorial non-pharmacological interventions for patients with CI and delirium may improve management of this patient group, and reduce prescriptions of antipsychotic, hypnotic and sedative medications. The implementation in clinical practice of early screening using quality improvement methodology deserves attention.

Trial registration

The protocol of this study was retrospectively registered in the ClinicalTrials.gov Protocol Registration and Results System with the registration number: NCT04737733 and date of registration: 03/02/2021.

'Brain fog', guilt, and gratitude: experiences of symptoms and life changes in older survivors 6 months after hospitalisation for COVID-19

Aim

The aim of the study is to explore older participants’ experiences of symptoms and life changes approximately 6 months after hospitalisation for COVID-19.

Findings

The participants experienced various persistent physical and cognitive symptoms. At the same time, they experienced gratitude for having survived and for having achieved new life perspectives.

Message

Despite suffering from the post-COVID-19 condition the older adults’ coping resources helped them achieve new life perspectives.

Purpose

Several of those who have been infected with COVID-19 suffer from the post-COVID-19 condition months after the acute infection. Little is known about how older survivors have experienced the consequences and how these have affected their lives. The aim of this study was to explore how older survivors experienced post-COVID-19 condition and life changes approximately 6 months after hospitalisation for COVID-19.

Methods

The study had an explorative and descriptive design. Semi-structured interviews were performed with 17 participants from two local hospitals, 11 men and 6 women, aged 60 years and older (age range 60–96), approximately 6 months after hospitalisation for COVID-19. A thematic descriptive analysis inspired by Braun and Clarke was used.

Results

Two main themes and seven subthemes were revealed. The main themes were: From few to various persistent symptoms and Existential thoughts and reflections. Most of the participants experienced various physical and/or cognitive symptoms, such as reduced physical fitness, heavy breathing, fatigue, and ‘brain fog’. On the other hand, they also experienced guilt and gratitude for having survived. The recognition of having achieved other life perspectives was also present.

Conclusion

Six months after undergone COVID-19 the participants still experienced various distressing symptoms, which were in line with larger studies. The novel findings of this study were connected to the existential area, where the patients’ thoughts and reflections of guilt, gratitude, and new life perspectives were revealed. These findings are important for health professionals to consider when treating patients after COVID-19.

Positive scores on the 4AT delirium assessment tool at hospital admission are linked to mortality, length of stay and home time: two-centre study of 82,770 emergency admissions

BACKGROUND

Studies investigating outcomes of delirium using large-scale routine data are rare. We performed a two-centre study using the 4 'A's Test (4AT) delirium detection tool to analyse relationships between delirium and 30-day mortality, length of stay and home time (days at home in the year following admission).

METHODS

The 4AT was performed as part of usual care. Data from emergency admissions in patients ≥65 years in Lothian, UK (n = 43,946) and Salford, UK (n = 38,824) over a period of $\sim$3 years were analysed using logistic regression models adjusted for age and sex.

RESULTS

4AT completion rates were 77% in Lothian and 49% in Salford. 4AT scores indicating delirium (≥4/12) were present in 18% of patients in Lothian, and 25% of patients in Salford. Thirty-day mortality with 4AT ≥4 was 5.5-fold greater than the 4AT 0/12 group in Lothian (adjusted odds ratio (aOR) 5.53, 95% confidence interval [CI] 4.99-6.13) and 3.4-fold greater in Salford (aOR 3.39, 95% CI 2.98-3.87). Length of stay was more than double in patients with 4AT scores of 1-3/12 (indicating cognitive impairment) or ≥ 4/12 compared with 4AT 0/12. Median home time at 1 year was reduced by 112 days (Lothian) and 61 days (Salford) in the 4AT ≥4 group (P < 0.001).

CONCLUSIONS

Scores on the 4AT used at scale in practice are strongly linked with 30-day mortality, length of hospital stay and home time. The findings highlight the need for better understanding of why delirium is linked with poor outcomes and also the need to improve delirium detection and treatment.

Discharge Destinations of Delirious Patients: Findings from a Prospective Cohort Study of 27,026 Patients From a Large Health Care System

OBJECTIVES

Delirium is known to contribute to increased rates of institutionalization and mortality. The full extent of adverse outcomes, however, remains understudied. We aimed to systematically assess the discharge destinations and mortality risk in delirious patients in a large sample across all hospital services.

DESIGN

Pragmatic prospective cohort study of consecutive admissions to a large health care system.

SETTING AND PARTICIPANTS

A total of 27,026 consecutive adults (>18 years old) with length of stay of at least 24 hours in a tertiary care center from January 1 to December 31, 2014.

METHODS

Presence of delirium determined by routine delirium screening. Clinical characteristics, discharge destination, and mortality were collected. Calculation of odds ratios (ORs) with logistic regression with adjustment for age, sex, and Charlson comorbidity index (CCI).

RESULTS

Delirium was detected in 19.7% of patients (5313 of 27,026), median age of delirious patients was 56 years (25-75 interquartile range = 37-70). The electronic health record (DSM-5-based) delirium algorithm correctly identified 93.3% of delirium diagnoses made by consultation-liaison psychiatrists. Across services, the odds of delirious patients returning home was significantly reduced [OR 0.12; confidence interval (CI) 0.10-0.13; P < .001]. Rather, these patients were transferred to acute rehabilitation (OR 4.15; CI 3.78-4.55; P < .001) or nursing homes (OR 4.12; CI 3.45-4.93; P < .001). Delirious patients had a significantly increased adjusted mortality risk (OR 30.0; CI 23.2-39.4; P < .001).

CONCLUSIONS AND IMPLICATIONS

This study advances our understanding of the discharge destination across all services in adults admitted to a large hospital system. Delirium was associated with reduced odds of returning home, increased odds of discharge to a setting of higher dependency, and excess mortality independent of comorbidity, age, and sex. These findings emphasize the potentially devastating outcomes associated with delirium and highlight the need for timely diagnosis and hospital-wide management.

Evaluation of Bedside Tests of Attention and Arousal Assessing Delirium in Parkinson's Disease, Dementia, and Older Adults

BACKGROUND

Delirium is a serious acute neuropsychiatric condition associated with altered attention and arousal.

OBJECTIVE

To evaluate simple bedside tests for attention and arousal to detect delirium in those with and without Parkinson's disease (PD) and dementia.

METHODS

Participants from two prospective delirium studies were pooled comprising 30 with PD without cognitive impairment, 24 with Lewy body cognitive impairment (PD dementia or dementia with Lewy bodies), 16 with another dementia and 179 PD and dementia-free older adults. Participants completed standardised delirium assessments including tests of attention: digit span, Memorial Delirium Assessment Scale (MDAS) attention and months of the year backwards; and arousal: Glasgow Coma Scale (GSC), Observational Scale of Level of Arousal (OSLA), Modified Richmond Agitation Scale and MDAS consciousness. Delirium was diagnosed using the DSM-5 criteria.

RESULTS

On their first admission, 21.7%participants had prevalent delirium. Arousal measures accurately detected delirium in all participants (p < 0.01 for all), but only selected attention measures detected delirium in PD and dementia. In PD and dementia-free older adults, impaired digit span and OSLA were the optimal tests to detect delirium (area under the curve [AUC] = 0.838, p < 0.001) while in PD and dementia the optimal tests were MDAS attention and GCS (AUC=0.90 and 0.84, respectively, p < 0.001 for both).

CONCLUSION

Simple bedside tests of attention and arousal at a single visit could accurately detect delirium in PD, dementia and PD and dementia-free older adults; however, the optimal tests differed between groups. Combined attention and arousal scores increased accuracy, which could have clinical utility to aid the identification of delirium neurodegenerative disorders.

Population-Based Studies in Dementia and Ageing Research: A Local and National Experience in Cambridgeshire and the UK

Dementia has been recognised as a key challenge in many ageing societies across the world. Several population-based studies have been developed to investigate dementia and cognitive ageing from perspectives of biology, health, psychology and social sciences. However, there is a need to provide a better understanding of 'contexts', the circumstance where these ageing populations existed, and heterogeneity within and across the populations in different time and places. In this article, we summarise some examples of earlier population-based studies undertaken by our research groups in England and Wales and their contribution to the epidemiology of dementia, neuropathology, cognitive and mental health in older age. We also describe how these studies illustrated variation among ageing populations and changes in their health conditions across time and place. These findings highlight the contribution that population-based studies can make, along with the vital to incorporate contexts in ageing research. A lifecourse approach within social context is needed to integrate life experiences, social circumstances, and multiple dimensions of cognition, functioning, physical health and wellbeing over the ageing process. We also discuss how evidence from population-based studies can support various international initiatives on dementia, healthy ageing and Sustainable Development Goals and facilitate tailored approaches for diverse populations across global societies.

Cognitive Trajectories Following Acute Infection in Older Patients With and Without Cognitive Impairment: An 1-Year Follow-Up Study

Introduction: Dementia is a known risk factor for both delirium and acute systemic infections which may also play a significant role in promoting or accelerating neurodegenerative disease. Infections are both the main causes of hospitalization of dementia patients and can be a major precipitant of delirium but currently it is not possible to predict the risk of cognitive decline in older patients exposed to acute infection. Objectives: We aimed to determine the level of cognitive change at 1-year follow up in individuals with different patterns of cognitive function (dementia, delirium, delirium superimposed on dementia) at the time of their hospitalization due to a systemic infection and to correlate these cognitive patterns with clinical status variables. Methods: We recruited 53 hospitalized geriatric patients with a systemic infection, and we collected 12-months follow up data for 34 patients. These patients were classified in four groups: no cognitive impairment (controls-C), delirium only (D), dementia only (Dem), and delirium superimposed to dementia (DD). Cognitive performance was measured by change in score on the Montreal Cognitive Assessment (MoCA) and delirium was identified using Confusion Assessment Measure (CAM). We examined performance on the MoCA in the first year after hospitalization, controlling for demographic characteristics, coexisting medical conditions, and type of infection. Results: For the 34 patients to whom follow-up data was available, delirium presence in individuals with prior dementia (DD group) was associated with a negative mean change score of 3-point (p < 0.02) at 1 year follow up, whereas dementia patients without delirium had a mean change score of 1.5-point lower at 12-months (p = 0.04), when comparing follow-up and baseline MoCA scores. Cognitively healthy patients did not significantly decrease their MoCA score at follow-up (p = 0.15). MoCA and NPI scores during hospitalization were significantly correlated with the level of cognitive decline in the four groups (r = 0.658, p < 0.01 and r = 0.439, p = 0.02, respectively). Conclusions: Premorbid dementia and delirium superimposed on dementia during hospitalization in older patients with acute infections predict cognitive decline at 1 year following admission. Taken together, our findings suggest a pathophysiological interaction between neurodegenerative changes, acute infection, and delirium.

Characterizing the long-term cognitive impairment following delirium episodes: A call to action

The possible link between delirium and a long-term cognitive impairment is significant for patients, carers, and clinicians. To make progress, we need urgently novel advances in understanding the neural substrates underlying this cognitive impairment and any accompanying behavioral symptoms.