Delirium and long-term cognitive impairment

Partial Wwox Loss of Function Increases Severity of Murine Sepsis and Neuroinflammation

Rationale

WW domain-containing oxidoreductase ( WWOX ) is a gene associated implicated in both neurologic and inflammatory diseases and is susceptible to environmental stressors. We hypothesize partial loss of Wwox function will result in increased sepsis severity and neuroinflammation.

Methods

Wwox WT/P47T mice, generated by CRISPR/Cas9, and Wwox WT/WT mice were treated with intraperitoneal PBS vs LPS (10mg/kg) and euthanized 12 hours post-injection. Open Field Testing (OFT) and Murine Sepsis Severity Scores (MSS) were utilized to measure sickness behavior and sepsis severity, respectively. Brain tissue was analyzed using immunohistochemistry and PCR to measure neuroinflammation and apoptosis.

Results

Wwox WT/P47T LPS mice demonstrated a more significant response to sepsis with an increase in sickness behavior, sepsis severity, gliosis, and apoptosis compared to Wwow WT/WT LPS littermates.

Conclusions

Partial loss of Wwox function increases risk for severe sepsis and neuroinflammation. Given the susceptibility of WWOX to environmental stressors, this may be a target for future therapeutic interventions.

Modulating delirium through stimulation (MoDeSt): study protocol for a randomized, double-blind, sham-controlled trial assessing the effect of postoperative transcranial electrical stimulation on delirium incidence

BACKGROUND

Postoperative delirium (POD) is the most common neurological adverse event among elderly patients undergoing surgery. POD is associated with an increased risk for postoperative complications, long-term cognitive decline, an increase in morbidity and mortality as well as extended hospital stays. Delirium prevention and treatment options are currently limited. This study will evaluate the effect of transcranial electrical stimulation (tES) on the incidence of POD.

METHODS

We will perform a randomized, double-blind, sham-controlled trial using single-session postoperative application of tES in the recovery room in 225 patients (> 65 years) undergoing elective major surgery. Patients will be randomly allocated (ratio 1:1:1) to one of three study groups: (1) alpha-tACS over posterior parietal cortex [2 mA, 20 min], (2) anodal tDCS over left dorsolateral prefrontal cortex [2 mA, 20 min], (3) sham [2 mA, 30 s]. Delirium will be screened twice daily with the 3-min diagnostic interview Confusion Assessment Method (3D-CAM) in the 5 days following surgery. The primary outcome is the incidence of POD defined as at least one positive screening during the five first postoperative days compared between tACS and sham groups. Secondary outcomes include delirium severity, duration, phenotype, postoperative pain, postoperative nausea and vomiting, electroencephalographic (EEG) markers, and fluid biomarkers.

DISCUSSION

If effective, tES is a novel, easily applicable, non-invasive method to prevent the occurrence of POD. The comprehensive neurophysiological and biofluid assessments for markers of (neuro-)inflammation and neurodegeneration will shed light on the pathomechanisms behind POD and further elucidate the (after-)effects of tES. The potential implications for the postoperative recovery comprise enhanced patient safety, neurocognitive outcome, perioperative manageability but also reduced healthcare costs.

TRIAL REGISTRATION

German Clinical Trial Registry DRKS00033703. Registered on February 23, 2024.

Pharmacologic prophylaxis of postoperative delirium in elderly patients: A network meta-analysis of randomized controlled trials

BACKGROUND

The high incidence and mortality rates of postoperative delirium (POD) among elderly patients highlights the pressing need for tailored prophylactic strategies. Despite various pharmacologic prophylactic strategies have been reported effective, their overall benefit and safety remain unclear in the geriatric population. Our network meta-analysis (NMA) aimed to systematically evaluate and rank the effectiveness of various pharmacological interventions in preventing POD in elderly patients.

METHODS

We conducted an extensive search of PubMed, Embase, Cochrane Central Register of Controlled Trials, PsycINFO, and Google Scholar for randomized controlled trials (RCTs) published up to August 1, 2023. We included RCTs examining pharmacological prophylactic effects of POD in elderly patients. To extract data in alignment with predefined areas of interest, we employed the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. The primary outcome was the incidence of POD. For secondary outcomes, we evaluated tolerability through all-cause discontinuation or drop-out rates, as well as all-cause mortality.

RESULTS

Our analysis encompassed a total of 44 RCTs involving 11,178 patients. Out of these, 26 RCTs involved comparisons with placebo only. For delirium prevention, the treatment groups receiving atypical antipsychotics (odds ratio (OR) of 0.27 and 95% confidence interval (CI) of 0.12-0.58), haloperidol (OR of 0.42; 95% CI of 0.25-0.71), dexmedetomidine (OR of 0.51 and 95% CI of 0.37-0.71 and melatonergic agents (MMA) (OR of 0.57 and 95% CI of 0.33-0.98) had significantly lower rates of delirium compared to the placebo group. Notably, the atypical antipsychotics ranked as the most effective treatment. For tolerability, no statistically differences in rates of dropout discontinuation and all-cause mortality among groups allocated to the placebo or individual pharmacological treatments.

CONCLUSIONS

Based on indirect evidence, our network meta-analysis identified atypical antipsychotics, dexmedetomidine, MMA, and haloperidol as effective in preventing POD in the elderly, with atypical antipsychotics ranking highest. However, it is essential to note that these findings should be confirmed through further RCTs.

Principles of the Orthogeriatric Model of Care: A Primer

It is well known that over the last few decades, there has been significant growth of the aging population worldwide and especially in Europe, with an increase of more than two years per decade since the 1960's. Currently, in Europe, people aged over 65 years old represent 20% of the population, creating many new and complex challenges for national healthcare systems. In many countries, geriatric medicine is an established medical specialty, integrated into the primary and secondary care of the older population. In some countries, such as Portugal, specialist training in geriatric medicine is not available, even though the life-expectancy in Portugal is currently 81 years due to a decrease in fertility and mortality, and people aged over 60 currently represent nearly a third of the population. There is strong evidence in the medical literature that a fracture following a fall, and especially a neck of femur fracture, is one of the most serious events that can happen in an older person's lifetime. These fractures have been associated with increased morbidity, loss of independence, a high rate of institutionalization, and mortality. Rates of mortality after a year from femoral fractures have been proven to be three to four times higher than the expected in the general population, ranging between 15% to 36%. This emphasizes the importance of developing well-organized care pathways for these patients, which combine specialized geriatric care (also known as orthogeriatric care). This narrative review will focus on the core principles of orthogeriatric care and how medical professionals, including those who are not specialized in geriatric care, can effectively use them.

Prevalence and risk factors of postoperative delirium in tumor patients after free flap reconstruction: A systematic review and meta-analysis of case-control studies

BACKGROUND

Postoperative delirium is a severe complication of flap transplantation surgery, adversely affecting surgical prognoses. The intricate pathophysiology of postoperative delirium renders the elucidation of its risk factors challenging. This research aims to delineate the prevalence and the specific risk factors of postoperative delirium in patients with cancer undergoing free flap reconstruction through a systematic review and meta-analysis to enlighten proactive prevention measures.

METHODS

The researchers systematically queried both the international and Chinese databases. Searches were performed for publications from inception until September 14, 2023, using the terms "free tissue flaps," "delirium," "neoplasms," and "risk factors." Data synthesis and statistical analysis were conducted using Stata SE (version 15.0) to calculate the combined effect size for identified risk factors. Reported outcomes included weighted mean differences or odds ratios with their respective 95% confidence intervals.

RESULTS

Twelve case-control studies were included (ntotal = 3,256). Among them, 515 patients developed postoperative delirium after free flap surgery, compared with 2,741 patients who did not. The outcomes suggest that the risk factors include but are not limited to age, male, late neoplasm staging, use of hypnotic or antipsychotic, history of background diseases, psychiatric review, tracheotomy, and impaired wound healing. In contrast, early neoplasm staging and others are the protective factors with statistical significance. Multivariate analysis further identified significant correlations between preoperative albumin, perioperative blood transfusion, sleep disturbance, postoperative visual analog scale, postoperative albumin, smoking, and the appearance of postoperative delirium.

CONCLUSION

The determined risk factors were grouped into preoperative, intraoperative, and postoperative categories substantiated by current data to present instructions for postoperative delirium prevention.

Potential mechanisms of Shenmai injection against POCD based on network pharmacology and molecular docking

BACKGROUND

As the population ages, the number of patients with postoperative cognitive dysfunction increases. This study aims to investigate the mechanisms of Shenmai injection as a therapeutic strategy for postoperative cognitive dysfunction using a network pharmacology approach.

METHODS

Shenmai injection and its targets were retrieved from the Traditional Chinese Medicine Systems Pharmacology database. Postoperative cognitive dysfunction-associated protein targets were identified using the GeneCards and DisGeNET databases. Subsequently, a protein-protein interaction network was constructed using the String database. For treating postoperative cognitive dysfunction, the core targets of Shenmai injection were identified through topological analysis, followed by the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses performed for annotation. Molecular docking was performed on the screened core targets and components.

RESULTS

One hundred and eighty-two related targets of Shenmai injection in treating postoperative cognitive dysfunction were identified. Eleven active ingredients in Shenmai injection were detected to have a close connection with postoperative cognitive dysfunction-related targets. Additionally, Gene Ontology analysis revealed 10 biological processes, 10 cellular components and 10 molecular functions. The Kyoto Encyclopedia of Genes and Genomes analysis identified 20 signaling pathways. The docking results indicated five active ingredients from Shenmai injection can fit in the binding pockets of all three candidate targets.

CONCLUSIONS

Thus, the present work systematically explored the anti-postoperative cognitive dysfunction mechanism of potential targets and signaling pathways of Shenmai injection. These results provide an important reference for subsequent basic research on postoperative cognitive dysfunction.

Delirium in acute stroke is associated with increased cognitive and psychiatric symptoms over time: The Nor-COAST study

BACKGROUND

Delirium, an acute and fluctuating mental disturbance of attention, cognition, and consciousness, commonly occurs in acute stroke. Research on long-term outcomes of stroke patients experiencing delirium is limited, especially regarding cognitive and psychiatric symptoms.

METHODS

As part of the Nor-COAST study, 373 patients were screened for delirium using the Confusion Assessment Method (CAM) in the acute phase of stroke. Patients were included in the mixed-model linear regression analyses if they had available data from the follow-ups at three, 18 or 36 months, totaling 334 (44.6 % women, mean (SD) age: 72.1 (12.5) years, 17 (5.1 %) diagnosed with delirium). Global cognition was measured using the Montreal Cognitive Assessment (MoCA). Psychiatric symptoms were measured using the Hospital Anxiety and Depression Scale (HADS) and the Neuropsychiatric Inventory-Questionnaire (NPI-Q).

RESULTS

At three months, delirium was associated with a higher NPI-Q score (Mean (SD) 2.9 (3.6) vs 1.4 (2.2)). At 18 and 36 months, delirium was associated with a lower MoCA score (Mean (SD) 19.7 (6.6) vs 24.3 (5.0), and 20.6 (7.6) vs 24.6 (4.8)), higher HADS anxiety symptoms (5.0 (4.3) vs 3.3 (3.3), and 5.9 (4.1) vs 3.4 (3.6)), higher HADS depression symptoms (7.2 (4.7) vs 3.4 (3.3), and 6.6 (5.1) vs 3.7 (3.7)), and higher NPI-Q score (2.4 (4.4) vs 1.7 (2.3), 2.6 (4.5) vs 1.0 (1.9)). Delirium significantly predicted the psychiatric symptoms hallucinations and agitation.

CONCLUSIONS

Patients with delirium in the acute phase of stroke may be particularly vulnerable to developing cognitive and psychiatric symptoms in the chronic phase.

Characterizing medical patients with delirium: A cohort study comparing ICD-10 codes and a validated chart review method

BACKGROUND

Delirium is a major cause of preventable mortality and morbidity in hospitalized adults, but accurately determining rates of delirium remains a challenge.

OBJECTIVE

To characterize and compare medical inpatients identified as having delirium using two common methods, administrative data and retrospective chart review.

METHODS

We conducted a retrospective study of 3881 randomly selected internal medicine hospital admissions from six acute care hospitals in Toronto and Mississauga, Ontario, Canada. Delirium status was determined using ICD-10-CA codes from hospital administrative data and through a previously validated chart review method. Baseline sociodemographic and clinical characteristics, processes of care and outcomes were compared across those without delirium in hospital and those with delirium as determined by administrative data and chart review.

RESULTS

Delirium was identified in 6.3% of admissions by ICD-10-CA codes compared to 25.7% by chart review. Using chart review as the reference standard, ICD-10-CA codes for delirium had sensitivity 24.1% (95%CI: 21.5-26.8%), specificity 99.8% (95%CI: 99.5-99.9%), positive predictive value 97.6% (95%CI: 94.6-98.9%), and negative predictive value 79.2% (95%CI: 78.6-79.7%). Age over 80, male gender, and Charlson comorbidity index greater than 2 were associated with misclassification of delirium. Inpatient mortality and median costs of care were greater in patients determined to have delirium by ICD-10-CA codes (5.8% greater mortality, 95% CI: 2.0-9.5 and $6824 greater cost, 95%CI: 4713-9264) and by chart review (11.9% greater mortality, 95%CI: 9.5-14.2% and $4967 greater cost, 95%CI: 4415-5701), compared to patients without delirium.

CONCLUSIONS

Administrative data are specific but highly insensitive, missing most cases of delirium in hospital. Mortality and costs of care were greater for both the delirium cases that were detected and missed by administrative data. Better methods of routinely measuring delirium in hospital are needed.

Using machine-learning to decode postoperative hip mortality Trends: Actionable insights from an extensive clinical dataset

BACKGROUND

Hip fractures are one of the most common injuries experienced by the general population. Despite advances in surgical techniques, postoperative mortality rates remain high. identifying relevant clinical factors associated with mortality is essential to preoperative risk stratification and tailored post-surgical interventions to improve patient outcomes. The purpose of this study aimed to identify preoperative risk factors and develop predictive models for increased hip fracture-related mortality within 30 days post-surgery, using one of the largest patient cohorts to date.

METHODS

Data from the American College of Surgeons National Surgical Quality Improvement Program database, comprising 107,660 hip fracture patients treated with surgical fixation was used. A penalized regression approach, least absolute shrinkage and selection operator was employed to develop two predictive models: one using preoperative factors and the second incorporating both preoperative and postoperative factors.

RESULTS

The analysis identified 68 preoperative factor outcomes associated with 30-day mortality. The combined model revealed 84 relevant factors, showing strong predictive power for determining postoperative mortality, with an AUC of 0.83.

CONCLUSIONS

The study's comprehensive methodology provides risk assessment tools for clinicians to identify high-risk patients and optimize patient-specific care.

The impact of burn injury on the central nervous system

Burn injuries can be devastating, with life-long impacts including an increased risk of hospitalization for a wide range of secondary morbidities. One area that remains not fully understood is the impact of burn trauma on the central nervous system (CNS). This review will outline the current findings on the physiological impact that burns have on the CNS and how this may contribute to the development of neural comorbidities including mental health conditions. This review highlights the damaging effects caused by burn injuries on the CNS, characterized by changes to metabolism, molecular damage to cells and their organelles, and disturbance to sensory, motor and cognitive functions in the CNS. This damage is likely initiated by the inflammatory response that accompanies burn injury, and it is often long-lasting. Treatments used to relieve the symptoms of damage to the CNS due to burn injury often target inflammatory pathways. However, there are non-invasive treatments for burn patients that target the functional and cognitive damage caused by the burn, including transcranial magnetic stimulation and virtual reality. Future research should focus on understanding the mechanisms that underpin the impact of a burn injury on the CNS, burn severity thresholds required to inflict damage to the CNS, and acute and long-term therapies to ameliorate deleterious CNS changes after a burn.

Susceptibility to acute cognitive dysfunction in aged mice is underpinned by reduced white matter integrity and microgliosis

Age is a significant but heterogeneous risk factor for acute neuropsychiatric disturbances such as delirium. Neuroinflammation increases with aging but the determinants of underlying risk for acute dysfunction upon systemic inflammation are not clear. We hypothesised that, with advancing age, mice would become progressively more vulnerable to acute cognitive dysfunction and that neuroinflammation and neuronal integrity might predict heterogeneity in such vulnerability. Here we show region-dependent differential expression of microglial transcripts, but a ubiquitously observed primed signature: chronic Clec7a expression and exaggerated Il1b responses to systemic bacterial LPS. Cognitive frailty (vulnerability to acute disruption under acute stressors LPS and double stranded RNA; poly I:C) was increased in aged animals but showed heterogeneity and was significantly correlated with reduced myelin density, synaptic loss and severity of white matter microgliosis. The data indicate that white matter disruption and neuroinflammation may be key substrates of the progressive but heterogeneous risk for delirium in aged individuals.

Prevalence of Cognitive Impairment and Dementia After Intracerebral Hemorrhage

Objective

To study the prevalence of cognitive impairment in survivors of intracerebral hemorrhage (ICH).

Methods

Survivors of spontaneous ICH were followed up in the neurology outpatient department when they reported for follow-up after 6 months. Neuroimaging records at the onset and at follow-up visits are studied for the location of ICH, volume of ICH, intraventricular extension, and hydrocephalus. The volume of ICH is calculated by ABC/2 method on a CT scan. All patients underwent cognitive assessment with Addenbrooke's cognitive examination ACE III and were categorized as patients having cognitive impairment (or) no cognitive impairment.

Results

A total of 120 patients were studied, out of which 77 (64%) are males and 43 (36%) are females with age groups ranging from 26 to 75 years. In the study population, the mean age was found to be 62.3 years. Specifically, the mean age for males was 56.9 years, while for females it was 63.4 years. Cognitive impairment was noted in 34 of 120 patients (28%) during 6 to 12 months of examination, of which 11 of 19 were in lobar location, 21 of 94 were in sub-cortical location, and 2 of 7 were in infratentorial location.

Conclusion

It was found that 28% of survivors of ICH were cognitively impaired. Hence, it is essential to assess cognition in post-ICH patients during follow-up, so that suitable adjustments can be made in their employment, and also in educating family members in providing a good quality of life.

Delirium and Healthcare Utilization in Patients Undergoing Hematopoietic Stem Cell Transplantation

Delirium, a common neuropsychiatric syndrome among hospitalized patients, has been associated with significant morbidity and mortality in patients undergoing hematopoietic stem cell transplantation (HSCT). Although delirium is often reversible with prompt diagnosis and appropriate management, timely screening of hospitalized patients, including HSCT recipients at risk for delirium, is lacking. The association between delirium symptoms and healthcare utilization among HSCT recipients is also limited. We conducted a retrospective analysis of 502 hospitalized patients admitted for allogeneic or autologous HSCT at 2 tertiary care hospitals between April 2016 and April 2021. We used Natural Language Processing (NLP) to identify patients with delirium symptoms, as defined by an NLP-assisted chart review of the electronic health record (EHR). We used multivariable regression models to examine the associations between delirium symptoms, clinical outcomes, and healthcare utilization, adjusting for patient-, disease-, and transplantation-related factors. Overall, 44.4% (124 of 279) of patients undergoing allogeneic HSCT and 39.0% (87 of 223) of those undergoing autologous HSCT were identified as having delirium symptoms during their index hospitalization. Two-thirds (139 of 211) of the patients with delirium symptoms were prescribed treatment with antipsychotic medications. Among allogeneic HSCT recipients, delirium symptoms were associated with longer hospital length of stay (β = 7.960; P < .001), fewer days alive and out of the hospital (β = -23.669; P < .001), and more intensive care unit admissions (odds ratio, 2.854; P = .002). In autologous HSCT recipients, delirium symptoms were associated with longer hospital length of stay (β = 2.204; P < .001). NLP-assisted EHR review is a feasible approach to identifying hospitalized patients, including HSCT recipients at risk for delirium. Because delirium symptoms are negatively associated with health care utilization during and after HSCT, our findings underscore the need to efficiently identify patients hospitalized for HSCT who are at risk of delirium to improve their outcomes. © 2023 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

Boosting Delirium Identification Accuracy With Sentiment-Based Natural Language Processing: Mixed Methods Study

BACKGROUND

Delirium is an acute neurocognitive disorder that affects up to half of older hospitalized medical patients and can lead to dementia, longer hospital stays, increased health costs, and death. Although delirium can be prevented and treated, it is difficult to identify and predict.

OBJECTIVE

This study aimed to improve machine learning models that retrospectively identify the presence of delirium during hospital stays (eg, to measure the effectiveness of delirium prevention interventions) by using the natural language processing (NLP) technique of sentiment analysis (in this case a feature that identifies sentiment toward, or away from, a delirium diagnosis).

METHODS

Using data from the General Medicine Inpatient Initiative, a Canadian hospital data and analytics network, a detailed manual review of medical records was conducted from nearly 4000 admissions at 6 Toronto area hospitals. Furthermore, 25.74% (994/3862) of the eligible hospital admissions were labeled as having delirium. Using the data set collected from this study, we developed machine learning models with, and without, the benefit of NLP methods applied to diagnostic imaging reports, and we asked the question "can NLP improve machine learning identification of delirium?"

RESULTS

Among the eligible 3862 hospital admissions, 994 (25.74%) admissions were labeled as having delirium. Identification and calibration of the models were satisfactory. The accuracy and area under the receiver operating characteristic curve of the main model with NLP in the independent testing data set were 0.807 and 0.930, respectively. The accuracy and area under the receiver operating characteristic curve of the main model without NLP in the independent testing data set were 0.811 and 0.869, respectively. Model performance was also found to be stable over the 5-year period used in the experiment, with identification for a likely future holdout test set being no worse than identification for retrospective holdout test sets.

CONCLUSIONS

Our machine learning model that included NLP (ie, sentiment analysis in medical image description text mining) produced valid identification of delirium with the sentiment analysis, providing significant additional benefit over the model without NLP.

Relation Between Diabetes and Psychiatric Disorders

Depression, anxiety, and schizophrenia are all things that have been found to be linked to the mental health of diabetics. When combined with particular mental health conditions, the management of diabetes might become very challenging. The management of diabetes requires the patient to be actively involved and is contingent on the patient's adherence to prescribed lifestyle modifications, self-monitoring, and medication. Patients who struggle to keep their mental health concerns under control are more likely to have trouble managing their diabetes on their own. People who have diabetes, because it is one of the most cognitively and behaviorally taxing chronic medical conditions, may be especially susceptible to developing mental health disorders. It is more prevalent in those who suffer from mental problems than it is in the general population. Diabetics frequently struggle with a variety of mental health conditions, including but not limited to schizophrenia, anxiety, and depression. Diagnosing and treating mental health disorders is an important component of diabetes treatment that can be accomplished through the collaborative efforts of members of a multidisciplinary team. Patients who fall into this category can benefit from a wide range of services provided by pharmacists who work with them, including individual assessments, joint goal-setting, skill development, ongoing monitoring, and medication management. These services are designed to help patients feel better and function better.

Microglial Response in Triggering Receptor Expressed on Myeloid Cells 2 (Trem2) Knock-Out Mice After Systemic Stimulation with Escherichia Coli

BACKGROUND

Systemic infection is an important risk factor for delirium, associated with neurodegeneration and subsequent cognitive impairment in older people. Microglial cell response is a known key player in this process and we hypothesize that the triggering receptor expressed on myeloid cells 2 (TREM2) plays an important role in the regulation of this response.

METHODS

8- to 10-week old male wild-type (WT) and TREM2 knock-out (Trem2^-/-) mice were intraperitoneally inoculated with live Escherichia coli (E. coli) or saline. After inoculation, all mice were treated with ceftriaxone (an antimicrobial drug) at 12 and 24 hours and were sacrificed after 2 and 3 days. Microglial response was determined by immunohistochemical staining with an ionized calcium-binding adaptor molecule 1 (Iba-1) antibody and flow cytometry. mRNA expression of pro- and anti-inflammatory mediators was measured to quantify the inflammatory response.

RESULTS

We observed increased Iba-1 positive cells number in thalamus of Trem2^-/- mice at 3d after inoculation compared to WT mice (mean 120 cell/mm² [SD 8] vs. 105 cell/mm² [SD 11]; p=0.03). Flow cytometry showed no differences in forward scatter or expression of CD11b, CD45 and CD14 between WT and Trem2^-/- mice. The brain mRNA expression levels of tumor necrosis factor alpha (TNF-α) of Trem2^-/- mice at 2d were higher compared to WT mice (p=0.003). Higher mRNA expression of interleukin 1 beta (IL-1β), Iba-1, CD11b and mitogen-activated protein kinase 1 (MAPK-1) was found in brain of WT mice at 2d compared to Trem2^-/- mice (respectively p=0.02; p=0.001; p=0.03 and p=0.02). In spleen there were no differences in inflammatory mediators, between WT and Trem2^-/- mice.

INTERPRETATION

Although the loss of function of TREM2 during systemic infection led to an increased number of activated microglia in the thalamus, we did not observe a consistent increase in expression of inflammatory genes in the brain. The role of TREM2 in the neuro-inflammatory response following systemic infection therefore appears to be limited.

Epigenetic Mechanisms of Postoperative Cognitive Impairment Induced by Anesthesia and Neuroinflammation

Cognitive impairment after surgery is a common problem, affects mainly the elderly, and can be divided into postoperative delirium and postoperative cognitive dysfunction. Both phenomena are accompanied by neuroinflammation; however, the precise molecular mechanisms underlying cognitive impairment after anesthesia are not yet fully understood. Anesthesiological drugs can have a longer-term influence on protein transcription, thus, epigenetics is a possible mechanism that impacts on cognitive function. Epigenetic mechanisms may be responsible for long-lasting effects and may implicate novel therapeutic approaches. Hence, we here summarize the existing literature connecting postoperative cognitive impairment to anesthesia. It becomes clear that anesthetics alter the expression of DNA and histone modifying enzymes, which, in turn, affect epigenetic markers, such as methylation, histone acetylation and histone methylation on inflammatory genes (e.g., TNF-alpha, IL-6 or IL1 beta) and genes which are responsible for neuronal development (such as brain-derived neurotrophic factor). Neuroinflammation is generally increased after anesthesia and neuronal growth decreased. All these changes can induce cognitive impairment. The inhibition of histone deacetylase especially alleviates cognitive impairment after surgery and might be a novel therapeutic option for treatment. However, further research with human subjects is necessary because most findings are from animal models.

Epidemiology of delirium in hospitalized patients in Latin America: A systematic review

BACKGROUND

Accurate epidemiological data are essential for the planning of policies aimed at the identification, prevention, and management of delirium. The reported occurrence of delirium in hospitalized patients varies widely among studies, ranging between 5% to more than 80% in the international literature. The exact occurrence in Latin America is not well described.

OBJECTIVE

The aim of this study is to conduct a systematic analysis of the published data on the epidemiology of delirium in hospitalized patients in Latin America.

METHODS

We conducted a systematic review following PRISMA guidelines. Both MEDLINE and LILACS databases were searched for original research articles reporting the occurrence of delirium among adult hospitalized patients in Latin American countries. Studies including pediatric populations were excluded from this analysis. Two authors independently applied eligibility criteria, assessed quality, and extracted data. The corresponding authors of the original articles were contacted to obtain relevant information about the study when this was not present in the published manuscripts.

RESULTS

Seven hundred and eighteen original articles were identified. After screening titles and abstracts, 149 studies were included in the final analysis. The occurrence of delirium varied depending on the clinical scenario: (1) in the general medico-surgical wards, it ranged from 2.1% to 60.4%, (2) in the Intensive Care Units (ICUs), from 9.6% to 94.8%, (3) in the post-operatory population, from 5.45% and 52.3%, and (4) it was found to be between 10.7% and 62% in the emergency department setting. The most used delirium assessment tools were the "Confusion Assessment Method" (CAM; in the general population), and the "Confusion Assessment Method for the ICU" (CAM-ICU). Fourteen out of 149 studies were conducted in clinical settings who actively implemented some form of non-pharmacological delirium prevention bundles, most of them as part of ICU sedation-analgesia protocols.

CONCLUSION

Delirium occurs frequently in hospitalized patients in Latin America throughout a variety of clinical scenarios, including ICU, general wards, post-operatory populations, and among the emergency department setting. The CAM and the CAM-ICU are the most used delirium assessment tools. Bundles of non-pharmacological interventions to prevent delirium are not universally implemented.

The relationship of acute delirium with cognitive and psychiatric symptoms after stroke: a longitudinal study

OBJECTIVE

Delirium, a common complication after stroke, is often overlooked, and long-term consequences are poorly understood. This study aims to explore whether delirium in the acute phase of stroke predicts cognitive and psychiatric symptoms three, 18 and 36 months later.

METHOD

As part of the Norwegian Cognitive Impairment After Stroke Study (Nor-COAST), 139 hospitalized stroke patients (49% women, mean (SD) age: 71.4 (13.4) years; mean (SD) National Institutes of Health Stroke Scale (NIHSS) 3.0 (4.0)) were screened for delirium with the Confusion Assessment Method (CAM). Global cognition was measured with the Montreal Cognitive Assessment (MoCA), while psychiatric symptoms were measured using the Hospital Anxiety and Depression Scale (HADS) and the Neuropsychiatric Inventory-Questionnaire (NPI-Q). Data was analyzed using mixed-model linear regression, adjusting for age, gender, education, NIHSS score at baseline and premorbid dementia.

RESULTS

Thirteen patients met the criteria for delirium. Patients with delirium had lower MoCA scores compared to non-delirious patients, with the largest between-group difference found at 18 months (Mean (SE): 20.8 (1.4) versus (25.1 (0.4)). Delirium was associated with higher NPI-Q scores at 3 months (Mean (SE): 2.4 (0.6) versus 0.8 (0.1)), and higher HADS anxiety scores at 18 and 36 months, with the largest difference found at 36 months (Mean (SE): 6.2 (1.3) versus 2.2 (0.3)).

CONCLUSIONS

Suffering a delirium in the acute phase of stroke predicted more cognitive and psychiatric symptoms at follow-up, compared to non-delirious patients. Preventing and treating delirium may be important for decreasing the burden of post-stroke disability.

Twelve-Month Cognitive and Functional Outcomes Following Cardiac Surgery: The DEXACET Trial of Intravenous Acetaminophen Versus Placebo

Background: Delirium, an acute decline in attention and global cognitive dysfunction, occurs frequently following cardiac surgery and has been demonstrated to be significantly associated with cognitive dysfunction and reduced functional ability. In the DEXACET trial, we demonstrated a significant reduction in postoperative in-hospital delirium with intravenous (IV) acetaminophen when compared with placebo. In this analysis we examined whether this protective association also extended to 12 month cognitive and functional outcomes.

Methods: This study was a prospective, randomized, placebo-controlled, triple-blinded, factorial design trial conducted at Beth Israel Deaconess Medical Center, approved by the IRB. In this trial, 120 older cardiac surgical patients were randomly assigned to receive either intravenous (IV) acetaminophen or placebo in addition to propofol or dexmedetomidine. Those receiving IV acetaminophen displayed a significant reduction in in-hospital delirium. We collected cognitive, mood and functional outcome data using the Montreal Cognitive Assessment, telephone version (T-MoCA), Geriatric Depression Scale (GDS) and the Basic and Instrumental Activities of Daily Living (ADLs, IADLs) at 1 month and 12 months after surgery.

Results: Of the 120 enrolled patients in the primary trial, 93 (77.5%) and 83 (69.2%) patients responded to assessments at 1 month and 12 months, respectively. No statistically significant differences in median T-MoCA scores were observed between acetaminophen and placebo groups at 1 month (18.0 vs.18.0, p = 0.52) or 12 months (19.0 vs.18.0, p = 0.62) following surgery. There were similarly no differences in GDS, ADLs or IADLs between treatment groups. Losses to follow-up limited the sample sizes and 10 of the 23 (45%) original study participants who had postoperative delirium were lost to follow up.

Conclusion: Administration of intravenous acetaminophen was not associated with a difference in long term cognitive or functional status following cardiac surgery. Additional research on long-term outcomes following postoperative delirium with a larger sample size and improved cohort retention strategies will be needed to address this important area.

Caring for patients with cognitive dysfunction, fluctuations and dementia caused by Parkinson's disease

Cognitive dysfunction is one of the most prevalent non-motor symptoms in patients with Parkinson's disease (PD). While it tends to worsen in the later stages of disease, it can occur at any time, with 15-20% of patients exhibiting cognitive deficits at diagnosis (Aarsland et al., 2010; Goldman and Sieg, 2020). The characteristic features of cognitive dysfunction include impairment in executive function, visuospatial abilities, and attention, which vary in severity from subtle impairment to overt dementia (Martinez-Horta and Kulisevsky, 2019). To complicate matters, cognitive dysfunction is prone to fluctuate in PD patients, impacting diagnosis and the ability to assess progression and decision-making capacity. The diagnosis of cognitive impairment or dementia has a huge impact on patient independence, quality of life, life expectancy and caregiver burden (Corallo et al., 2017; Lawson et al., 2016; Leroi et al., 2012). It is therefore essential that physicians caring for patients with PD provide education, screening and treatment for this aspect of the disease. In this chapter, we provide a practical guide for the assessment and management of various degrees of cognitive dysfunction in patients with PD by approaching the disease at different stages. We address risk factors for cognitive dysfunction, prevention strategies prior to making the diagnosis, available tools for screening. Lastly, we review aspects of care, management and considerations, including decision-making capacity, that occur after the patient has been diagnosed with cognitive dysfunction or dementia.

Management of Delirium in the Intensive Care Unit

In the intensive care unit, delirium is a major contributor to morbidity and mortality in adult patients. Patients with delirium have been shown to have increased length of stay, decreased functional outcomes, and increased risk for requiring placement at the time of discharge. In addition, decreased cognitive function and dementia have been shown to be long-term complications from delirium. The mainstay of treatment and prevention include therapy- and behavioral-based interventions, including frequent orientation, cognitive stimulation, mobilization, sleep restoration, and providing hearing and visual aids. Refractory delirium may require pharmacologic intervention with antipsychotics or alpha-2 agonists.

Major Surgery and Long Term Cognitive Outcomes: The Effect of Postoperative Delirium on Dementia in the Year Following Discharge

BACKGROUND

Delirium is among the most common complications following major surgery. Delirium following medical illness is associated with the development of chronic cognitive decline. The objective of this study was to determine the association of postoperative delirium with dementia in the year following surgery.

MATERIALS AND METHODS

This was a retrospective cohort study in a large health network (January 2013 to December 2019). All patients over age 50 undergoing surgery requiring an inpatient stay were included. Our main exposure was an episode of delirium. The primary outcome was a new dementia diagnosis in the 1 y following discharge. Secondary outcomes included hospital length of stay, non-home discharge destination, mortality and rehospitalizations in 1 y.

RESULTS

There were 39,665 patients included, with a median age of 66. There were 4156 of 39,665 emergencies (10.5%). Specialties were general surgery (12,285/39,665, 31%) and orthopedics (11,503/39,665, 29%). There were 3327 (8.4%) patients with delirium. Delirious patients were older and were more likely to have comorbid conditions and undergone complex procedures. There were 1353 of 39,665 (3.5%) patients who developed dementia in the year following their surgery; 4930 of 39,665 (12.4%) who died; and 8200 of 39,665 (20.7%) who were readmitted. Delirium was associated with a new dementia diagnosis after adjusting for baseline characteristics (Odds ratio [OR] 13.9; 95% CI, 12.2-15.7). Similarly, delirium was also associated with 1 y mortality (OR 3.1; 95% CI 2.9-3.4) and readmission (OR 1.9, 95% CI 1.7-2.0).

CONCLUSIONS

Postoperative delirium is the strongest factor associated with development of dementia in the year following a major operation. Strategies to prevent, identify, and treat delirium in the postoperative setting may improve long-term cognitive recovery.

Implementation of the telephone montreal cognitive assessment in a telemedicine based pre-admission testing clinic during COVID-19

Introduction

Postoperative delirium (POD) affects 10-70% of patients 60 years or older and has been linked to increasing length of hospitalization, mortality, and morbidity. Pre-existing cognitive impairment is a predictor of POD. COVID-19 restricted use of in-person cognitive screens. The Telephone Montreal Cognitive Assessment (T-MoCA) can screen for cognitive dysfunction remotely. We evaluated the feasibility of administering T-MoCA in a multiethnic population during pre-operative testing televisits.

Methods

Patients scheduled for surgery between July 2020 and August 2020 were asked to participate in the T-MoCA at the end of their preadmission testing (PAT) televisit. A retrospective chart review was conducted to collect patient comorbidities and demographics. Patients were stratified by negative (T-MoCA≥19) or positive (T-MoCA<19) for mild cognitive impairment (MCI) and compared using 2-tailed χ2-tests. Univariate logistic regression was used to identify associations between patient characteristics and positive T-MoCA result.

Results

Fifty out of 65 (77%) patients who consented to the T-MoCA completed the test. The average time to complete the assessment was 10.5 mins. Twenty two (44%) had a negative score and 28 (56%) had a positive score. Patients who had a positive T-MoCA were older (70.04±7.61 yrs) compared to those with a negative T-MoCA (67.68±4.69 yrs, p=0.007), although the distribution of patients above and below age 65 was not different (p=0.243). The two groups did not vary by gender, race/ethnicity, obesity, surgery type, or medical co-morbidities. When we examined our population for predictors of a positive T-MoCA, we found a trend toward men being less likely to score positive on T-MoCA (OR=0.33, 95% CI: 0.10-1.10, p=0.07) compared to women; and that patients with Hispanic race/ethnicity were more likely to test positive on the T-MoCA (OR=4.13, 95% CI: 0.84-20.28, p=0.08) compared to Non-Hispanic Whites.

Conclusions

Implementation of the T-MoCA in a telemedicine-based PAT setting is feasible. In our cohort, most people who consented to the assessment completed it, and more than half scored positively, which may have important implications on the surgical plan and post-operative recovery. There may be limitations in using T-MoCA in certain populations, such as non-English preferred language, hearing difficulties, lack of focus, and use of external aids, which would need to be explored in a larger sample size.

Delirium in adult patients in intensive care: nursing interventions

BACKGROUND

Delirium is a neuropsychiatric syndrome of high incidence in the critically ill patient. It is characterised by changes in acute attention and cognition, has a multifactorial aetiology and has a negative impact on the patient's clinical situation and future quality of life. Prevention of delirium and early identification can reduce associated morbidity and mortality. Consequently, it is vital that intensive care unit (ICU) nurses perform targeted patient monitoring to identify acute cognitive changes.

OBJECTIVE

To identify nursing interventions directed at the prevention and management of delirium in adult patients in ICU.

METHOD

A scoping review was undertaken based on the principles recommended by the Joanna Briggs Institute.

RESULTS

Seven studies were selected for inclusion. Non-pharmacological and pharmacological nursing interventions were identified.

CONCLUSION

The interventions identified were predominantly aimed at the prevention of delirium. The training of nurses and wider clinical team in preventing and identifying this syndrome is crucial.

Probable Delirium and Associated Patient Characteristics in Long-Term Care and Complex Continuing Care: A Population-Based Observational Study

OBJECTIVES

To estimate the prevalence of probable delirium in long-term care (LTC) and complex continuing care (CCC) settings and to describe the resident characteristics associated with probable delirium.

DESIGN

Population-based cross-sectional study using routinely collected administrative health data.

SETTING AND PARTICIPANTS

All LTC and CCC residents in Ontario, Canada, assessed with the Resident Assessment Instrument-Minimum Dataset (RAI-MDS) assessment between July 1, 2016, and December 31, 2016 (LTC n=86,454, CCC n=10,217).

METHODS

Probable delirium was identified via the delirium Clinical Assessment Protocol on the RAI-MDS assessment, which is triggered when individuals display at least 1 of 6 delirium symptoms that are of recent onset and different from their usual functioning. RAI-MDS assessments were linked to demographic and health services utilization databases to ascertain resident demographics and health status. Multivariable logistic regression was used to identify characteristics associated with probable delirium, with adjusted odds ratios (ORs) and 95% confidence intervals (CIs) reported.

RESULTS

Delirium was probable in 3.6% of LTC residents and 16.5% of CCC patients. LTC patients displayed fewer delirium symptoms than CCC patients. The most common delirium symptom in LTC was periods of lethargy (44.6% of delirium cases); in CCC, it was mental function varying over the course of the day (63.5% of delirium cases). The odds of probable delirium varied across individual demographics and health characteristics, with increased health instability having the strongest association with the outcome in both care settings (LTC: OR 30.4, 95% CI 26.2-35.3; CCC: OR 21.0, 95% CI 16.7-26.5 for high vs low instability).

CONCLUSIONS AND IMPLICATIONS

There were differences in the presentation and burden of delirium symptoms between LTC and CCC, potentially reflecting differences in delirium severity or symptom identification. Several risk factors for probable delirium in LTC and CCC were identified that may be amenable to interventions to prevent this highly distressing condition.

Impaired Executive Function and Depression as Independent Risk Factors for Reported Delirium Symptoms: An Observational Cohort Study Over 8 Years

BACKGROUND

Acute medical illnesses, surgical interventions, or admissions to hospital in older individuals are frequently associated with a delirium. In this cohort study, we investigated the impact of specific cognitive domains and depression before the occurrence of delirium symptoms in an 8-year observation of older non-hospitalized individuals.

METHODS

In total, we included 807 participants (48-83 years). Deficits in specific cognitive domains were measured using the CERAD test battery, and depressive symptoms were measured using Beck Depression Inventory and the Geriatric Depression Scale (GDS) before the onset of a delirium. Delirium symptoms were retrospectively assessed by a questionnaire based on the established Nursing Delirium Screening Scale.

RESULTS

Fifty-eight of eight hundred seven participants (7.2%) reported delirium symptoms over the 8-year course of the study. Sixty-nine percent (n = 40) of reported delirium symptoms were related to surgeries. In multivariate regression analysis, impaired executive function was an independent risk factor (p = 0.034) for the occurrence of delirium symptoms. Furthermore, age (p = 0.014), comorbidities [captured by the Charlson Comorbidity Index (CCI)] (p < 0.001), and depression (p = 0.012) were significantly associated with reported delirium symptoms.

CONCLUSION

Especially prior to elective surgery or medical interventions, screening for impaired executive function and depression could be helpful to identify patients who are at risk to develop delirium symptoms.

Why is delirium more frequent in the elderly?

An aging-related reduction in the brain's functional reserve may explain why delirium is more frequent in the elderly than in younger people insofar as the reserve becomes inadequate to cover the metabolic requirements that are critically increased by stressors. The aim of this paper is to review the normal aging-related changes that theoretically compromise complex mental activities, neuronal and synaptic densities, and the neurocomputational flexibility of the functional reserve. A pivotal factor is diminished connectivity, which is substantially due to the loss of synapses and should specifically affect association systems and cholinergic fibres in delirious patients. However, micro-angiopathy with impaired blood flow autoregulation, increased blood/brain barrier permeability, changes in cerebrospinal fluid dynamics, weakened mitochondrial performance, and a pro-inflammatory involution of the immune system may also jointly affect neurons and their synaptic assets, and even cause the progression of delirium to dementia regardless of the presence of co-existing plaques, tangles, or other pathological markers. On the other hand, the developmental growth in functional reserve during childhood and adolescence makes the brain increasingly resistant to delirium, and residual reserve can allow the elderly to recover. These data support the view that functional reserve is the variable that confronts stressors and governs the risk and intensity of and recovery from delirium. Although people of any age are at risk of delirium, the elderly are at greater risk because aging and age-dependent structural changes inevitably affect the brain's functional reserve.

Recurrent delirium over 12 months predicts dementia: results of the Delirium and Cognitive Impact in Dementia (DECIDE) study

Background

Delirium is common, distressing and associated with poor outcomes. Previous studies investigating the impact of delirium on cognitive outcomes have been limited by incomplete ascertainment of baseline cognition or lack of prospective delirium assessments. This study quantified the association between delirium and cognitive function over time by prospectively ascertaining delirium in a cohort aged ≥ 65 years in whom baseline cognition had previously been established.

Methods

For 12 months, we assessed participants from the Cognitive Function and Ageing Study II-Newcastle for delirium daily during hospital admissions. At 1-year, we assessed cognitive decline and dementia in those with and without delirium. We evaluated the effect of delirium (including its duration and number of episodes) on cognitive function over time, independently of baseline cognition and illness severity.

Results

Eighty two of 205 participants recruited developed delirium in hospital (40%). One-year outcome data were available for 173 participants: 18 had a new dementia diagnosis, 38 had died. Delirium was associated with cognitive decline (−1.8 Mini-Mental State Examination points [95% CI –3.5 to –0.2]) and an increased risk of new dementia diagnosis at follow up (OR 8.8 [95% CI 1.9–41.4]). More than one episode and more days with delirium (>5 days) were associated with worse cognitive outcomes.

Conclusions

Delirium increases risk of future cognitive decline and dementia, independent of illness severity and baseline cognition, with more episodes associated with worse cognitive outcomes. Given that delirium has been shown to be preventable in some cases, we propose that delirium is a potentially modifiable risk factor for dementia.

A systematic review and meta-analysis of the accuracy of the clock drawing test (CDT) in the identification of delirium in older hospitalised patients

Objective: Delirium is a common neurocognitive syndrome among hospitalised older adults. The clock drawing test (CDT) is a relatively simple bedside test of cognitive function. This systematic review and meta-analysis examine the accuracy of the CDT in identifying delirium in hospitalised older adults.Methods: PRISMA guidelines were used to report the identified studies. Pubmed, SCOPUS, and Ovid and EBSCO platforms (including MEDLINE ®, PsycINFO, PsycEXTRA, EMCARE, CINAHL and EMBASE databases) were searched. Studies were assessed for methodological quality using the Downs and Black Tool. Data were extracted regarding the number of delirious/not delirious, number with normal and abnormal CDT, age, and MMSE scores, and information regarding CDT scoring, criteria for diagnosis of delirium and setting of the study. Analysis was carried out with the "Mada" and "Metatron" packages of R software.Results: Fifteen studies were examined. The number of participants was 2199, of whom 597 (27.15%) were diagnosed with delirium. The overall sensitivity of CDT in the absence of any formal cognitive test was 0.76 (0.58-0.87) with specificity of 0.70 (0.51-0.83). When the MMSE was taken into account, the specificity and sensitivity reduced to 0.51. Diagnostic criteria for delirium, scoring method of CDT, age of participants and setting significantly (p < 0.05) affect the sensitivity and specificity of the CDT.Conclusion: Although, the CDT is generally considered to be a simple and easy to administer screening tool for cognitive impairment in older hospitalised adults, when a more formal cognitive test is used its sensitivity and specificity to detect delirium is low.

Aging and Microglial Response following Systemic Stimulation with Escherichia coli in Mice

Systemic infection is an important risk factor for the development cognitive impairment and neurodegeneration in older people. Animal experiments show that systemic challenges with live bacteria cause a neuro-inflammatory response, but the effect of age on this response in these models is unknown. Young (2 months) and middle-aged mice (13-14 months) were intraperitoneally challenged with live Escherichia coli (E. coli) or saline. The mice were sacrificed at 2, 3 and 7 days after inoculation; for all time points, the mice were treated with ceftriaxone (an antimicrobial drug) at 12 and 24 h after inoculation. Microglial response was monitored by immunohistochemical staining with an ionized calcium-binding adaptor molecule 1 (Iba-1) antibody and flow cytometry, and inflammatory response by mRNA expression of pro- and anti-inflammatory mediators. We observed an increased microglial cell number and moderate morphologically activated microglial cells in middle-aged mice, as compared to young mice, after intraperitoneal challenge with live E. coli. Flow cytometry of microglial cells showed higher CD45 and CD11b expressions in middle-aged infected mice compared to young infected mice. The brain expression levels of pro-inflammatory genes were higher in middle-aged than in young infected mice, while middle-aged infected mice had similar expression levels of these genes in the systemic compartment. We conclude that systemic challenge with live bacteria causes an age-dependent neuro-inflammatory and microglial response. Our data show signs of an age-dependent disconnection of the inflammatory transcriptional signature between the brain and the systemic compartment.

Frequency and Causes of Delirium in Pediatric Intensive Care Unit: A Prospective Observational Study

Background

The number of studies evaluating delirium and its frequency in critically ill infants, children, and adolescents is increasing day by day. The primary objective of this study was to evaluate all patients hospitalized in our pediatric intensive care unit (PICU) in terms of pediatric delirium, to determine the frequency and risk factors of pediatric delirium.

Patients and methods

The patients included in this study had been hospitalized in the PICU between November 1, 2018, and August 31, 2019, and were followed up for more than 48 hours.

Results

Delirium was detected in 14 patients (9.9%) through regular evaluations. The Pediatric Index of Mortality 2 (PIM2) scores and the length of stay in the PICU were higher in patients with delirium (p = 0.03 and p = 0.01, respectively). The use of respiratory support, sedation-analgesia, vasoactive and corticosteroid treatments, and physical restraints were higher in patients with delirium and were statistically significant (p <0.05). Following admission to the PICU, psychosocial interventions were implemented for 76.1% of the whole cohort. Delirium developed in only five (4.5%) of the 108 patients who underwent psychosocial interventions, while it was detected in nine (26.5%) of the 34 patients who did not receive psychosocial interventions (p = 0.001). The psychosocial intervention was associated with a lower likelihood of delirium (odds ratio [OR], 0.237; p = 0.044). An increasing number of days in the PICU was independently associated with increasing odds of delirium (OR, 1.095; p = 0.037 for each day).

Conclusions

We observed that the risk factors associated with delirium were similar to previous studies. Additionally, psychosocial intervention before delirium symptoms developed was associated with a lower risk of developing delirium. However, multicenter randomized controlled trials are needed on this subject.

How to cite this article

Yontem A, Yildizdas D, Horoz OO, et al. Frequency and Causes of Delirium in Pediatric Intensive Care Unit: A Prospective Observational Study. Indian J Crit Care Med 2021;25(6):715-719.

Protocol for the Prognosticating Delirium Recovery Outcomes Using Wakefulness and Sleep Electroencephalography (P-DROWS-E) study: a prospective observational study of delirium in elderly cardiac surgical patients

INTRODUCTION

Delirium is a potentially preventable disorder characterised by acute disturbances in attention and cognition with fluctuating severity. Postoperative delirium is associated with prolonged intensive care unit and hospital stay, cognitive decline and mortality. The development of biomarkers for tracking delirium could potentially aid in the early detection, mitigation and assessment of response to interventions. Because sleep disruption has been posited as a contributor to the development of this syndrome, expression of abnormal electroencephalography (EEG) patterns during sleep and wakefulness may be informative. Here we hypothesise that abnormal EEG patterns of sleep and wakefulness may serve as predictive and diagnostic markers for postoperative delirium. Such abnormal EEG patterns would mechanistically link disrupted thalamocortical connectivity to this important clinical syndrome.

METHODS AND ANALYSIS

P-DROWS-E (Prognosticating Delirium Recovery Outcomes Using Wakefulness and Sleep Electroencephalography) is a 220-patient prospective observational study. Patient eligibility criteria include those who are English-speaking, age 60 years or older and undergoing elective cardiac surgery requiring cardiopulmonary bypass. EEG acquisition will occur 1-2 nights preoperatively, intraoperatively, and up to 7 days postoperatively. Concurrent with EEG recordings, two times per day postoperative Confusion Assessment Method (CAM) evaluations will quantify the presence and severity of delirium. EEG slow wave activity, sleep spindle density and peak frequency of the posterior dominant rhythm will be quantified. Linear mixed-effects models will be used to evaluate the relationships between delirium severity/duration and EEG measures as a function of time.

ETHICS AND DISSEMINATION

P-DROWS-E is approved by the ethics board at Washington University in St. Louis. Recruitment began in October 2018. Dissemination plans include presentations at scientific conferences, scientific publications and mass media.

TRIAL REGISTRATION NUMBER

NCT03291626.

Association of Positive Delirium Screening with Incident Dementia in Skilled Nursing Facilities

BACKGROUND AND OBJECTIVE

Early detection of delirium in skilled nursing facilities (SNFs) is a priority. The extent to which delirium screening leads to a potentially inappropriate diagnosis of Alzheimer's disease and related dementia (ADRD) is unknown.

DESIGN

Nationwide retrospective cohort study from 2011 to 2013.

SETTING

An SNF.

PARTICIPANTS

A total of 1,175,550 Medicare enrollees who entered the SNF from a hospital and had no prior diagnosis of dementia.

EXPOSURE

A positive screen for delirium using the validated Confusion Assessment Method (CAM), performed as part of the federally mandated Minimum Data Set (MDS) assessment.

MEASUREMENTS

Incident all-cause dementia, ascertained through International Classification of Diseases, Ninth Revision (ICD-9), diagnosis in Medicare claims or active diagnoses in MDS.

RESULTS

Positive screening for delirium was identified in 7.7% of cases (n = 90,449), and most occurred within the first 7 days of SNF admission (62.5%). The overall incidence of ADRD was 6.3% (n = 73,542). Nearly all new diagnoses of ADRD (93.5%) occurred within the first 30 days of SNF admission. Patients who screened CAM positive for delirium had a nearly threefold increased risk of receiving an incident ADRD diagnosis on the same day (hazard ratio (HR) = 2.63; 95% confidence interval (CI) = 1.50-4.63). Among patients who screened CAM positive for delirium, those who were cognitively intact or had mild cognitive impairments were, on average, six times more likely to receive an incident ADRD diagnosis (HR = 6.64; 95% CI = 1.76-25.0) relative to those testing CAM negative.

CONCLUSION AND RELEVANCE

Among older adults not previously diagnosed with dementia, a positive screen for delirium was significantly associated with higher risk of ADRD diagnosis after admission to a SNF. This risk was highest for patients in the first days of their stay and with the least cognitive impairment, suggesting that the ADRD diagnosis was potentially inappropriate.

Microglia: A Potential Therapeutic Target for Sepsis-Associated Encephalopathy and Sepsis-Associated Chronic Pain

Neurological dysfunction, one of the severe manifestations of sepsis in patients, is closely related to increased mortality and long-term complications in intensive care units, including sepsis-associated encephalopathy (SAE) and chronic pain. The underlying mechanisms of these sepsis-induced neurological dysfunctions are elusive. However, it has been well established that microglia, the dominant resident immune cell in the central nervous system, play essential roles in the initiation and development of SAE and chronic pain. Microglia can be activated by inflammatory mediators, adjacent cells and neurotransmitters in the acute phase of sepsis and then induce neuronal dysfunction in the brain. With the spotlight focused on the relationship between microglia and sepsis, a deeper understanding of microglia in SAE and chronic pain can be achieved. More importantly, clarifying the mechanisms of sepsis-associated signaling pathways in microglia would shed new light on treatment strategies for SAE and chronic pain.

The 4 'A's test for detecting delirium in acute medical patients: a diagnostic accuracy study

BACKGROUND

Delirium is a common and serious neuropsychiatric syndrome, usually triggered by illness or drugs. It remains underdetected. One reason for this is a lack of brief, pragmatic assessment tools. The 4 'A's test (Arousal, Attention, Abbreviated Mental Test - 4, Acute change) (4AT) is a screening tool designed for routine use. This project evaluated its usability, diagnostic accuracy and cost.

METHODS

Phase 1 - the usability of the 4AT in routine practice was measured with two surveys and two qualitative studies of health-care professionals, and a review of current clinical use of the 4AT as well as its presence in guidelines and reports. Phase 2 - the 4AT's diagnostic accuracy was assessed in newly admitted acute medical patients aged ≥ 70 years. Its performance was compared with that of the Confusion Assessment Method (CAM; a longer screening tool). The performance of individual 4AT test items was related to cognitive status, length of stay, new institutionalisation, mortality at 12 weeks and outcomes. The method used was a prospective, double-blind diagnostic test accuracy study in emergency departments or in acute general medical wards in three UK sites. Each patient underwent a reference standard delirium assessment and was also randomised to receive an assessment with either the 4AT (n = 421) or the CAM (n = 420). A health economics analysis was also conducted.

RESULTS

Phase 1 found evidence that delirium awareness is increasing, but also that there is a need for education on delirium in general and on the 4AT in particular. Most users reported that the 4AT was useful, and it was in widespread use both in the UK and beyond. No changes to the 4AT were considered necessary. Phase 2 involved 785 individuals who had data for analysis; their mean age was 81.4 (standard deviation 6.4) years, 45% were male, 99% were white and 9% had a known dementia diagnosis. The 4AT (n = 392) had an area under the receiver operating characteristic curve of 0.90. A positive 4AT score (> 3) had a specificity of 95% [95% confidence interval (CI) 92% to 97%] and a sensitivity of 76% (95% CI 61% to 87%) for reference standard delirium. The CAM (n = 382) had a specificity of 100% (95% CI 98% to 100%) and a sensitivity of 40% (95% CI 26% to 57%) in the subset of participants whom it was possible to assess using this. Patients with positive 4AT scores had longer lengths of stay (median 5 days, interquartile range 2.0-14.0 days) than did those with negative 4AT scores (median 2 days, interquartile range 1.0-6.0 days), and they had a higher 12-week mortality rate (16.1% and 9.2%, respectively). The estimated 12-week costs of an initial inpatient stay for patients with delirium were more than double the costs of an inpatient stay for patients without delirium (e.g. in Scotland, £7559, 95% CI £7362 to £7755, vs. £4215, 95% CI £4175 to £4254). The estimated cost of false-positive cases was £4653, of false-negative cases was £8956, and of a missed diagnosis was £2067.

LIMITATIONS

Patients were aged ≥ 70 years and were assessed soon after they were admitted, limiting generalisability. The treatment of patients in accordance with reference standard diagnosis limited the ability to assess comparative cost-effectiveness.

CONCLUSIONS

These findings support the use of the 4AT as a rapid delirium assessment instrument. The 4AT has acceptable diagnostic accuracy for acute older patients aged > 70 years.

FUTURE WORK

Further research should address the real-world implementation of delirium assessment. The 4AT should be tested in other populations.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN53388093.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 40. See the NIHR Journals Library website for further project information. The funder specified that any new delirium assessment tool should be compared against the CAM, but had no other role in the study design or conduct of the study.

Downregulation of synapse-associated protein expression and loss of homeostatic microglial control in cerebrospinal fluid of infectious patients with delirium and patients with Alzheimer's disease

Delirium is a complex and multifactorial condition associated with long-term cognitive decline. Due to the strong links between systemic inflammation, delirium and dementia we hypothesized that responses within the brain in patients who develop delirium could show biochemical overlap with patients with Alzheimer's disease (AD). In this observational study we analyzed protein expression signatures in cerebrospinal fluid (CSF) from 15 patients with infectious delirium and compared these to 29 patients with AD, 30 infectious patients without delirium and 15 non-infectious controls free of neurological disease. A proximity extension assay was performed measuring a total of 184 inflammatory and neurology-related proteins. Eight inflammatory proteins (4%), including the key neuron-microglia communication marker CX3CL1 (fractalkine), were significantly upregulated in both delirium and AD, compared to infectious patients without delirium. Likewise, 23 proteins (13%) showed downregulation in both delirium and AD, relative to infectious patients without delirium, which interestingly included CD200R1, another neuron-microglia communication marker, as well as a cluster of proteins related to synapse formation and function. Synaptopathy is an early event in AD and correlates strongly with cognitive dysfunction. These results were partially mediated by aging, which is an important predisposing risk factor among many others for both conditions. Within this study we report the first in vivo human evidence suggesting that synapse pathology and loss of homeostatic microglial control is involved in the pathophysiology of both infectious delirium and AD and thus may provide a link for the association between infections, delirium and long-term cognitive decline.

Delirium, insulin-like growth factor I, growth hormone in older inpatients

BACKGROUND

Delirium is a common disorder in elderly medical inpatients with serious adverse outcomes and is characterized by sudden onset, disturbance in attention, awareness, consciousness and cognition, and often with behavioural disturbances. Central to understanding delirium, is understanding mechanisms by which body and brain wellbeing are linked and in particular how brain responses to bodily homeostatic stress is mediated. A number of studies have investigated the relationship between insulin-like growth factor I (IGF-I) and delirium in medically ill hospitalised patients with conflicting results. However, none have investigated growth hormone (GH) which is related to IGF-I via negative feedback.

AIM

To investigate the relationship between serum levels of IGF-I and GH, and the occurrence of delirium.

METHODS

Prospective, longitudinal, observational study. Consecutive elderly inpatients (aged 70+), were assessed twice weekly with Montreal cognitive assessment (MoCA), Confusion assessment method (CAM), Acute Physiology and Chronic Health Evaluation II. Delirium was defined using CAM. Previous history of dementia was evaluated with the Informant Questionnaire on Cognitive Decline in the Elderly. IGF-I and GH levels were estimated with the ELISA method. Generalized estimating equations (GEE) model was applied for the first five assessments to analyze those longitudinal data.

RESULTS

The sample consisted of 198 participants (mean age 80.63 ± 6.81; range 70-97). Of these 92 (46.5%) were females. Eighty six (43.4%) were identified with a history of dementia. Incident or prevalent delirium during hospitalisation was identified with CAM in 40 participants (20.2%). Evaluation of missing values with Little's MCAR test indicated that they were missing completely at random (MCAR χ² = 12.24, u: 9, P = 0.20). Using GEE for the analysis we found that low MoCA scores, low levels of IGF-I and high levels of GH were significantly associated with any delirium (prevalence, incident, or fluctuating , during the study period (Wald χ² = 12.231; u: 1, P < 0.001, Wald χ² = 7.196, u: 1, P = 0.007, Wald χ² = 6.210; : u: 1, P = 0.013 respectively).

CONCLUSION

The results show that low levels of IGF-I, high levels of GH and low scores in cognition are independently associated with the occurrence of any delirium during the hospitalisation of medically ill older people. The results of the study supports the hypothesis that deficits in the immunoreactivity of the brain (low cerebral reserve) may be associated with delirium.

Neuropsychological functioning in severe acute respiratory disorders caused by the coronavirus: Implications for the current COVID-19 pandemic

Objective: The coronavirus class of respiratory viruses - including Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19) - has been associated with central nervous system (CNS) disease. In fact, multiple mechanisms of CNS involvement have been proposed, making it difficult to identify a unitary syndrome that can be the focus of clinical work and research. Neuropsychologists need to understand the potential cognitive and psychological sequelae of COVID-19 and the impact of the interventions (e.g., ICU, ventilation) that have been used in treating patients with severe forms of the illness.Method: We briefly review the literature regarding the neurological and neuropsychological effects of similar coronaviruses, the limited information that has been published to date on COVID-19, and the literature regarding the long-term cognitive and psychological effects of undergoing treatment in the intensive care unit (ICU).Results: We discuss the roles that neuropsychologists can play in assessing and treating the cognitive difficulties and psychiatric symptoms described.Conclusions: At this time, the mechanisms, correlates, and effects of COVID-19 are poorly understood, but information gleaned from the literature on similar viruses and utilized interventions should help inform neuropsychologists as they begin to work with this population.

The occurrence and timing of delirium in acute care hospitalizations in the last year of life: A population-based retrospective cohort study

BACKGROUND

Delirium is a distressing neurocognitive disorder that is common among terminally ill individuals, although few studies have described its occurrence in the acute care setting among this population.

AIM

To describe the prevalence of delirium in patients admitted to acute care hospitals in Ontario, Canada, in their last year of life and identify factors associated with delirium.

DESIGN

Population-based retrospective cohort study using linked health administrative data. Delirium was identified through diagnosis codes on hospitalization records.

SETTING/PARTICIPANTS

Ontario decedents (1 January 2014 to 31 December 2016) admitted to an acute care hospital in their last year of life, excluding individuals age of <18 years or >105 years at admission, those not eligible for the provincial health insurance plan between their hospitalization and death dates, and non-Ontario residents.

RESULTS

Delirium was recorded as a diagnosis in 8.2% of hospitalizations. The frequency of delirium-related hospitalizations increased as death approached. Delirium prevalence was higher in patients with dementia (prevalence ratio: 1.43; 95% confidence interval: 1.36-1.50), frailty (prevalence ratio: 1.67; 95% confidence interval: 1.56-1.80), or organ failure-related cause of death (prevalence ratio: 1.23; 95% confidence interval: 1.16-1.31) and an opioid prescription (prevalence ratio: 1.17; 95% confidence interval: 1.12-1.21). Prevalence also varied by age, sex, chronic conditions, antipsychotic use, receipt of long-term care or home care, and hospitalization characteristics.

CONCLUSION

This study described the occurrence and timing of delirium in acute care hospitals in the last year of life and identified factors associated with delirium. These findings can be used to support delirium prevention and early detection in the hospital setting.

Post-traumatic stress disorder: A differential diagnostic consideration for COVID-19 survivors

Objective: SARS-CoV-2 infection and its oft-associated illness COVID-19 may lead to neuropsychological deficits, either through direct mechanisms (i.e., neurovirulance) or indirect mechanisms, most notably complications caused by the virus (e.g., stroke) or medical procedures (e.g., intubation). The history of past human coronavirus outbreaks resulting in similar health emergencies suggests there will be a substantial prevalence of post-traumatic stress disorder (PTSD) among COVID-19 survivors. To prepare neuropsychologists for the difficult task of differentiating PTSD-related from neuropathology-related deficits in the oncoming wave of COVID-19 survivors, we integrate research across a spectrum of related areas.Methods: Several areas of literature were reviewed: psychiatric, neurologic, and neuropathological outcomes of SARS and MERS patients; neurological outcomes in COVID-19 survivors; PTSD associated with procedures common to COVID-19 patients; and differentiating neuropsychological deficits due to PTSD from those due to acquired brain injuries in other patient groups.Conclusions: Heightened risk of PTSD occurred in MERS and SARS survivors. While data concerning COVID-19 is lacking, PTSD is known to occur in patient groups who undergo similar hospital courses, including ICU survivors, patients who are intubated and mechanically ventilated, and those that experience delirium. Research with patients who develop PTSD in the context of mild traumatic brain injury further suggests that PTSD may account for some or all of a patient's subjective cognitive complaints and neuropsychological test performance. Recommendations are provided for assessing PTSD in the context of COVID-19.

Incidence and risk factors for acute delirium in older patients with a hip fracture: A retrospective cohort study

This retrospective cohort study aimed to determine the incidence, and preoperative, intraoperative, and postoperative risk factors for postoperative delirium in older patients undergoing surgical fixation of a hip fracture. Electronic medical records were examined of 260 patients who underwent a surgical fixation of a hip fracture between June 2017 and October 2018 at a university-affiliated tertiary care hospital in Victoria, Australia. Demographic, clinical, and perioperative data were examined for potential risk factors for postoperative delirium. Of the 260 patients, 63 patients (24.2%) developed delirium postoperatively. Univariate logistic regression analysis indicated that advanced age, comorbidity, cognitive impairment, dementia, American Society of Anesthesiologists score, and antipsychotic usage were significant risk factors for delirium, while doses of paracetamol, fentanyl, and diazepam showed complex associations. Multivariate logistic regression analysis determined comorbidity and cognitive impairment as independent risk factors for the development of delirium. This study demonstrates the importance of evaluation of medications prescribed in the perioperative period as modifiable risk factors, in order to identify patients at high risk of delirium and enable targeted monitoring and treatment during patients' hospitalization.

Sleep and Delirium in Older Adults

Purpose of Review

Poor sleep and delirium are common in older patients but recognition and management are challenging, particularly in the intensive care unit (ICU) setting. The purpose of this review is to highlight current research on these conditions, their inter-relationship, modes of measurement, and current approaches to management.

Recent Findings

Sleep deprivation and delirium are closely linked, with shared clinical characteristics, risk factors, and neurochemical abnormalities. Acetylcholine and dopamine are important neurochemicals in the regulation of sleep and wakefulness and their dysregulation has been implicated in development of delirium. In the hospital setting, poor sleep and delirium are associated with adverse outcomes; non-pharmacological interventions are recommended, but tend to be resource intensive and hindered by a lack of reliable sleep measurement tools. Delirium is easier to identify, with validated tools available in both ICU and non-ICU settings; however, an optimal treatment approach remains unclear. Antipsychotics are used widely to prevent and treat delirium, although the efficacy data are equivocal. Bundled non-pharmacologic approaches represent a promising framework for prevention and management.

Summary

Poor sleep and delirium are common problems in older patients. While these phenomena appear linked, a causal relationship is not clearly established. At present, there are no established sleep-focused guidelines for preventing or treating delirium. Novel interventions are needed that address poor sleep and delirium, particularly in older adults.

Delirium in hospitalised children

Delirium is a syndrome characterised by an acute and fluctuating alteration in cognition and awareness. It occurs frequently in children with serious medical illness, and is associated with adverse outcomes such as increased length of hospital stay, duration of mechanical ventilation, hospital costs, and mortality. Delirium-especially the hypoactive subtype-is often overlooked by paediatric practitioners, but can be reduced by mitigating risks and effectively managed if detected early. Non-modifiable risk factors of delirium include young age (age <2 years), cognitive or neurological disabilities, need for invasive mechanical ventilation, severe underlying illness and pre-existing chronic conditions, and poor nutritional status. Routine bedside screening using validated tools can enable early detection of delirium. To reduce delirium in hospitalised children, health-care providers should optimise the hospital environment (eg, by reducing sleep disruption and keeping the child stimulated during the day), improve pain management, and decrease sedation (particularly use of benzodiazepines).

Common Bacterial Infections and Risk of Dementia or Cognitive Decline: A Systematic Review

BACKGROUND

Bacterial infections may be associated with dementia, but the temporality of any relationship remains unclear.

OBJECTIVES

To summarize existing literature on the association between common bacterial infections and the risk of dementia and cognitive decline in longitudinal studies.

METHODS

We performed a comprehensive search of 10 databases of published and grey literature from inception to 18 March 2019 using search terms for common bacterial infections, dementia, cognitive decline, and longitudinal study designs. Two reviewers independently performed the study selection, data extraction, risk of bias and overall quality assessment. Data were summarized through a narrative synthesis as high heterogeneity precluded a meta-analysis.

RESULTS

We identified 3,488 studies. 9 met the eligibility criteria; 6 were conducted in the United States and 3 in Taiwan. 7 studies reported on dementia and 2 investigated cognitive decline. Multiple infections were assessed in two studies. All studies found sepsis (n = 6), pneumonia (n = 3), urinary tract infection (n = 1), and cellulitis (n = 1) increased dementia risk (HR 1.10; 95% CI 1.02-1.19) to (OR 2.60; 95% CI 1.84-3.66). The range of effect estimates was similar when limited to three studies with no domains at high risk of bias. However, the overall quality of evidence was rated very low. Studies on cognitive decline found no association with infection but had low power.

CONCLUSION

Our review suggests common bacterial infections may be associated with an increased risk of subsequent dementia, after adjustment for multiple confounders, but further high-quality, large-scale longitudinal studies, across different healthcare settings, are recommended to further explore this association.

Common bacterial infections and risk of incident cognitive decline or dementia: a systematic review protocol

INTRODUCTION

The global burden of dementia is rising, emphasising the urgent need to develop effective approaches to risk reduction. Recent evidence suggests that common bacterial infections may increase the risk of dementia, however the magnitude and timing of the association as well as the patient groups affected remains unclear. We will review existing evidence of the association between common bacterial infections and incident cognitive decline or dementia.

METHODS AND ANALYSIS

We will conduct a comprehensive search of published and grey literature from inception to 18 March 2019. The following electronic databases will be searched; MEDLINE, EMBASE, Global health, PsycINFO, Web of Science, Scopus, Cochrane Library, the Cumulative Index to Nursing and Allied Health Literature, Open Grey and the British Library of Electronic Theses databases. There will be no restrictions on the date, language or geographical location of the studies. We will include longitudinal studies with a common clinically symptomatic bacterial infection as an exposure and incident cognitive decline or dementia as an outcome. Study selection, data extraction and risk of bias will be performed independently by two researchers. We will assess the risk of bias using the Cochrane collaboration approach. The overall quality of the studies will be assessed using the Grading of Recommendations, Assessment, Development and Evaluations criteria. We will explore the heterogeneity of relevant studies and, if feasible, a meta-analysis will be performed, otherwise we will present a narrative synthesis. We will group the results by exposure and outcome definitions and differences will be described by subgroups and outcomes.

ETHICS AND DISSEMINATION

Ethical approval will not be required as this is a systematic review of existing research in the public domain. Results will be disseminated in a peer-reviewed journal and presented at national and international meetings and conferences.

PROSPERO REGISTRATION NUMBER

CRD42018119294.