Why is delirium more frequent in the elderly?

A Randomized Clinical Trial of Dexmedetomidine on Delirium, Cognitive Dysfunction, and Sleep After Non-Ambulatory Orthopedic Surgery With Regional Anesthesia

BACKGROUND

Postoperative delirium (POD), emergence delirium (ED), and postoperative cognitive dysfunction (POCD) are disorders of the neuropsychiatric spectrum affecting the elderly during the postoperative period, potentially sharing a common pathophysiological pathway. Disrupted sleep postoperatively correlates with both POD and POCD, revealing overlapping risk factors. This study investigates the potential of dexmedetomidine anesthesia to reduce the incidence of POD (primary outcome), ED, POCD, impairment of sleep quality, and emergent chronic pain (secondary outcomes) in older adults undergoing major orthopedic surgery under regional anesthesia.

METHODS

In this double-blind randomized control trial, patients scheduled for major lower limb orthopedic surgery under regional anesthesia were randomized to receive either dexmedetomidine or propofol for sedation at a 1:1 ratio. POD, ED, and POCD were assessed with the Confusion Assessment Method tool, the Riker Sedation-Agitation scale, and the European Battery of psychometric tests, respectively. Sleep quality was assessed using the Pittsburg Sleep Quality Index and chronic pain with the painDETECT tool. Assessments of all outcome variables were performed before surgery, and at 48 hours and 3 months postoperatively.

RESULTS

A total of 80 patients (dexmedetomidine group n = 41) were enrolled in the study and completed the follow-up. POD, ED, and early POCD incidence were significantly lower in dexmedetomidine compared to propofol group (4.8% vs 38.4%, P = .001; 2.4% vs 38.4%, P < .001; 2.4% vs 56.4%, P < .001, respectively). Patients in the dexmedetomidine group reported improved sleep quality in the immediate postoperative period (lower PSQI score) and lower painDETECT scores at 3 months (4.4 ± 0.7 vs 13.4 ± 0.8, P < .001; 2.4 ± 0.9 vs 5.3 ± 0.9, P = .023, respectively). Intraoperative bradycardia and hemodynamic instability episodes were more common in the dexmedetomidine group while a single patient presented airway obstruction (2.4% vs 30.8%, P = .002) in the dexmedetomidine group.

CONCLUSIONS

Sedation with dexmedetomidine resulted in a statistically and clinically important reduction in the incidence of POD, ED, and early POCD, while it improved self-reported postoperative sleep quality and reduced chronic pain scores in patients undergoing major elective lower limb surgery under regional anesthesia.

Impact of prior SARS-CoV-2 infection on perioperative cardiac, pulmonary and neurocognitive complications in older patients: Study protocol for an observative case control study

BACKGROUND

Postoperative delirium is considered a serious complication in older patients. Older patients often suffer from several concomitant diseases. The reduced physical condition can increase the risk of cardiac, pulmonary and neurocognitive complications during and after surgery. SARS-CoV-2 infection primarily affects the respiratory tract but can also damage other organ systems such as the heart and brain. Given the wide range of pulmonary, cardiac and neurocognitive complications caused by SARS-CoV-2, these risks must be given special consideration during planned surgical procedures. Both surgical procedures and anesthesia are risk factors for postoperative complications in themselves. The specific impact of prior SARS-CoV-2 infection on perioperative complications in older patients has not been sufficiently researched. The aim of this study is to understand how a previous SARS-CoV-2 infection influences the occurrence of perioperative complications.

METHODS

In this case-control study, the data of patients over 60 years of age undergoing elective surgery are analyzed. Subjects are divided into two groups based on their SARS-CoV-2 infection status: those with a documented previous infection and those without. Confirmation of infection will be based on written evidence and anamnestic information. The primary endpoint of the examination is the occurrence of delirium within the first five postoperative days. In addition, further cardiac, pulmonary and neurocognitive complications are recorded in the perioperative period. The occurrence of postoperative delirium is recorded during the daily ward round in the first five days after surgery. The 3DCAM test and the 4AT are used for this purpose. In addition, the CAM-ICU will be used in the intensive care unit. The recruitment will include 266 patients. Statistical analyses will be performed to determine the correlation between a previous SARS-CoV-2 infection and the observed clinical outcomes.

DISCUSSION

The results of this study will provide new insights into the impact of prior SARS-CoV-2 infection on perioperative complications in older patients undergoing elective surgery.

TRIAL REGISTRATION

Deutsches Register Klinischer Studien: DRKS00034861.

Lipid dysregulation and delirium in older adults: A review of the current evidence and future directions

Delirium is a complex medical condition marked by acute episodes of cognitive dysfunction and behavioral disturbances, with a multifaceted etiology and challenging management across various clinical settings. Older adults, particularly in postoperative contexts, are at increased risk of developing delirium. Despite extensive research, a single underlying pathophysiological mechanism for delirium remains elusive. However, emerging evidence suggests a correlation between lipid dysregulation and delirium development in elderly patients, especially in postoperative settings. This connection has led to proposed treatments targeting dyslipidemia and associated neuroinflammatory effects in acute-phase delirium. This review aims to synthesize current literature on the relationship between lipid dysregulation and delirium in older adults, highlighting the need for further research into specific neurolipidome constituents and age-related lipid profile changes, potentially uncovering novel therapeutic strategies for delirium.

Association of remimazolam with delirium and cognitive function: A systematic review and meta-analysis of randomised controlled trials

BACKGROUND AND STUDY OBJECTIVE

Delirium is an organic mental syndrome significantly associated with long-term cognitive decline, increased hospital stays and higher mortality. This systematic review of randomised controlled trials (RCTs) with meta-analysis assesses the association of remimazolam with postoperative cognitive function and delirium compared with non-benzodiazepine hypnotics.

DESIGN

Systematic review of RCTs with meta-analysis.

DATA SOURCES

PubMed, Embase, Cochrane Library and Web of Science databases up to 27 April 2024.

ELIGIBILITY CRITERIA

Adult patients undergoing general anaesthesia or sedation procedures; use of remimazolam as the primary hypnotic or as an adjunct, administered via intermittent bolus or continuous infusion; comparison with other hypnotics or sedatives; evaluation of cognitive function or delirium.

MAIN RESULTS

Twenty-three RCTs with 3598 patients were included. The incidence of delirium was not significantly different between remimazolam and other sedatives in general anaesthesia and sedation procedures [ n  = 3261; odds ratio (OR) = 1.2, 95% confidence interval (CI), 0.76 to 1.91; P  = 0.378843; I2  = 17%]. Regarding cognitive function evaluation, remimazolam showed no difference compared with the control group in Mini-Mental State Examination (MMSE) scores on the first postoperative day ( n  = 263; mean difference = 0.60, 95% CI, -1.46 to 2.66; P  = 0.5684; I2  = 90%) or on the third postoperative day ( n  = 163; mean difference  = 1.33, 95% CI, -0.72 to 3.38; P  = 0.2028; I2  = 93%). Remimazolam exhibited superiority over the control group in MMSE scores on the seventh postoperative day ( n  = 247; mean difference = 0.53, 95% CI, 0.30 to 0.75; P  < 0.0001; I2  = 28%).

CONCLUSION

Remimazolam does not increase the incidence of delirium or cognitive impairments compared with non-benzodiazepine hypnotics. However, the analysis showed that the type of surgery significantly influenced the incidence of delirium. Additionally, remimazolam was associated with better short-term postoperative cognitive function.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42024532751.

Evaluation of postoperative delirium in cardiac surgery patients with the SDACS screening tool: a multicenter-multiphase study

OBJECTIVE

Postoperative delirium is a prevalent complication in cardiac surgery patients, highlighting the importance of early risk factor identification for optimal management. This study aimed to pinpoint risk factors and devise a novel screening tool, the Screening Tool for Delirium After Cardiac Surgery (SDACS), to predict postoperative delirium in cardiac surgery patients after the first day.

MATERIALS AND METHODS

This study employed a multiphase design consisting of three phases. In the first phase, through a scoping review of 38 finally selected published papers, 136 potential risk factors for identifying delirium after cardiac surgery were identified. These risk factors were then incorporated into three Delphi rounds of expert panels to develop a screening tool for postoperative delirium. Finally, 76 potential risk factors were examined on 920 cardiac surgery patients at three academic institutions between 2020 and 2023 (third phase of the study). All predictors were included into a screening instrument (SDACS), and the regression coefficient of each predictor was transformed into a risk score.

RESULTS

Delirium was diagnosed in 53% (n = 488) of 920 patients. Four independent predictors of delirium were identified: chronic opioid use (OR: 4.605, 95% CI: 2.163-9.804), hearing impairment (OR: 6.926, 95% CI: 3.630-12.215), benzodiazepine history (OR: 8.506, 95% CI: 5.651-11.805), and poor sleep quality on the first night after cardiac surgery (OR: 9.081, 95% CI: 6.225-12.248). The cross-validated area under receiver operating characteristics curve (AUC) for the screening instrument was 0.897 (95% CI: 0.876-0.916; P < 0.001).

CONCLUSION

Chronic opioid use, hearing impairment, benzodiazepine history, and poor sleep quality post-surgery are linked to postoperative delirium in cardiac surgery patients. The SDACS screening tool effectively forecasts this syndrome early, offering bedside nurses a valuable tool for prompt intervention and improved patient outcomes. The SDACS screening tool aids in early delirium risk assessment, enabling timely interventions and better patient outcomes. By predicting postoperative delirium accurately, nurses can address risk factors proactively, potentially reducing its incidence and severity, leading to improved postoperative outcomes for patients.

Brain Structural and Functional Changes Associated With Postoperative Neurocognitive Disorders: Research Update

Postoperative neurocognitive disorders (PNDs) are frequent and serious perioperative complications in the elderly, and are associated with increased morbidity and mortality, length of hospital stay, and need for long-term care. At present, the pathogenesis of PND is not completely clear, and there are various risk factors including surgical trauma and stress mediating systemic inflammation towards neuroinflammation development which causes brain structural and functional changes namely PND. For elderly patients, perioperative neurological monitoring may provide insights into brain function status. Monitoring may also help clinicians identify potential risks which would ultimately allow timely and effective intervention for better perioperative safety and prognosis for elderly patients. In this review, we summarize the risk factors and potential mechanisms of PND, and discuss preliminary evidence regarding application of electroencephalography, functional near-infrared spectroscopy, functional magnetic resonance, and positron emission tomography imaging in monitoring the central nervous system during the postoperative period.

Practical prognostic tools to predict the risk of postoperative delirium in older patients undergoing cardiac surgery: visual and dynamic nomograms

PURPOSE

Postoperative Delirium (POD) has an incidence of up to 65% in older patients undergoing cardiac surgery. We aimed to develop two dynamic nomograms to predict the risk of POD in older patients undergoing cardiac surgery.

METHODS

This was a single-center retrospective cohort study, which included 531 older patients who underwent cardiac surgery from July 2021 to June 2022 at Nanjing First Hospital, China. Univariable and multivariable logistic regression were used to identify the significant predictors used when constructing the models. We evaluated the performances and accuracy, validated, and estimated the clinical utility and net benefit of the models using the receiver operating characteristic (ROC), the 10-fold cross-validation, and decision curve analysis (DCA).

RESULTS

A total of 30% of the patients developed POD, the significant predictors in the preoperative model were ASA ( p < 0.001 OR = 3.220), cerebrovascular disease (p < 0.001 OR = 2.326), Alb (p < 0.037 OR = 0.946), and URE (p < 0.001 OR = 1.137), while for the postoperative model they were ASA (p = 0.044, OR = 1.737), preoperative MMSE score (p = 0.005, OR = 0.782), URE (p = 0.017 OR = 1.092), CPB duration (p < 0.001 OR = 1.010) and APACHE II (p < 0.001, OR = 1.353). The preoperative and postoperative models achieved satisfactory predictive performances, with AUC values of 0.731 and 0.799, respectively. The web calculators can be accessed at https://xxh152.shinyapps.io/Pre-POD/ and https://xxh152.shinyapps.io/Post-POD/ .

CONCLUSION

We established two nomogram models based on the preoperative and postoperative time points to predict POD risk and guide the flexible implementation of possible interventions at different time points.

Risk factors of delirium after cardiac surgery: a systematic review and meta-analysis

BACKGROUND

Post-operative delirium (POD) is a relatively common occurrence following surgical procedures, particularly cardiac surgeries. Given that the majority of pharmacologic treatments for delirium have demonstrated inadequate efficacy, it is of great importance to identify risk factors to prevent delirium or reduce its complications. Consequently, in this systematic review and meta-analysis, we identified risk factors of POD after cardiac surgery.

METHOD

A comprehensive search of the literature was conducted using the databases Scopus, PubMed, and Web of Science from the inception to April 22, 2024. The objective was to identify prospective cohorts that had assessed the risk factors associated with POD in patients undergoing cardiac surgery using multivariate regression.

RESULTS

Of the 3,166 studies that were initially screened, 23 were included in the review. Nine risk factors were evaluated including age (OR 1.06, 95% CI (1.04, 1.08), p < 0.001), pre-operative depression (OR 3.71, 95% CI (2.45, 5.62), p < 0.001), post-operative atrial fibrillation (AF) (OR 2.39, 95% CI (1.79, 3.21), p < 0.001), hypertension (HTN) (OR 1.64, 95% CI (0.75, 3.56), p = 0.212), age ≥ 65 (OR 3.32, 95% CI (2.40, 4.60), p < 0.001), pre-operative AF (OR 4.43, 95% CI (2.56, 7.69), p < 0.001), diabetes mellitus (OR 2.16, 95% CI (1.39, 3.35), p = 0.001), combined coronary artery bypass graft (CABG) + valve surgery (OR 2.73, 95% CI (1.66, 4.49), p < 0.001), and cardiopulmonary bypass (CPB) time (OR 1.02, 95% CI (1.01, 1.04), p = 0.001).

CONCLUSIONS

A total of nine risk factors were evaluated, from which eight were found to have a statistically significant effect on the risk of developing POD. These factors can be employed to more effectively identify at-risk patients and to prevent the occurrence of POD. Furthermore, this approach can facilitate earlier diagnosis and more effective patient care.

Incidence of Delirium in ICU Patients With and Without COVID-19 in a Costa Rican Hospital

INTRODUCTION

 Delirium is a common and serious neurological complication in intensive care units (ICUs), often leading to poor patient outcomes and increased mortality. This study aimed to compare the incidence of delirium in ICU patients with COVID-19 to those with other respiratory infections in a private hospital in Costa Rica. Additionally, it evaluated the prevalence, severity, duration, and treatment of delirium in these critically ill patients.

METHODS

A retrospective observational study was conducted, analyzing multiple variables obtained from the electronic health records of patients hospitalized in the ICU of Hospital Clinica Biblica. The study included patients admitted between January 2020 and December 2023. It compared the incidence of delirium among patients admitted for COVID-19 and those admitted for other diagnoses. The main outcomes measured were the incidence of delirium and the correlation of its management with international guidelines. The measures included the use of mechanical ventilation, the development of delirium, and the use of sedatives.

RESULTS

A total of 137 patients were analyzed, of whom 57.7% were over 70 years old, 67.2% were men, 45.2% were admitted with a diagnosis of COVID-19, 90.5% used mechanical ventilation, and 49.6% of patients developed delirium. Dexmedetomidine was the most used sedative, which was the only one that showed a significant relationship with the development of delirium (p=0.0002). Delirium management was mainly done through the administration of dexmedetomidine (52.9%) and quetiapine (41.2%). There was no correlation between delirium development and mortality (p=0.2670).

CONCLUSION

The study results do not show a significant relationship between COVID-19-positive patients and the development of delirium. Similarly, no higher mortality was observed in those patients who experienced delirium during their ICU stay.

Postoperative Delirium and the Older Adult: Untangling the Confusion

Postoperative delirium is one of the most prevalent postoperative complications, affecting mostly older adults. Its incidence is expected to rise because of surgical advances, shifting demographics, and increased life expectancy. Although an acute alteration in brain function, postoperative delirium is associated with adverse outcomes, including progressive cognitive decline and dementia, that place significant burdens on patients' lives and healthcare systems. This has prompted efforts to understand the mechanisms of postoperative delirium to provide effective prevention and treatment. There are multiple mechanisms involved in the etiology of postoperative delirium that share similarities with the physiological changes associated with the aging brain. In addition, older patients often have multiple comorbidities including increased cognitive impairment that is also implicated in the genesis of delirium. These tangled connections pinpointed a shift toward creation of a holistic model of the pathophysiology of postoperative delirium. Scientific advancements integrating clinical risk factors, possible postoperative delirium biomarkers, genetic features, digital platforms, and other biotechnical and information technological innovations, will become available in the near future. Advances in artificial intelligence, for example, will aggregate cognitive testing platforms with patient-specific postoperative delirium risk stratification studies, panels of serum and cerebrospinal fluid molecules, electroencephalogram signatures, and gut microbiome features, along with the integration of novel polygenetic variants of sleep and cognition. These advances will allow for the enrollment of high-risk patients into prevention programs and help uncover new pharmacologic targets.

Comparison of Remimazolam and Propofol on Postoperative Delirium in Elderly Patients Undergoing Radical Resection of Colon Cancer: A Single-Center Prospective Randomized Controlled Study

BACKGROUND We compared the effect of remimazolam and propofol intravenous anesthesia on postoperative delirium in elderly patients undergoing laparoscopic radical resection of colon cancer. MATERIAL AND METHODS One hundred patients undergoing elective radical operation of colon cancer under general anesthesia were divided into a remimazolam group (group R) and propofol group (group P) by a random number table method. During anesthesia induction and maintenance, group R was intravenously injected with remimazolam to exert sedation; however, in group P, propofol was injected instead of remimazolam. The occurrence of postoperative delirium was assessed with the Confusion Assessment Method for the Intensive Care Unit scale and postoperative pain was assessed with the visual analogue score (VAS). The primary outcome measures were the incidence and duration of delirium within 7 days following surgery. Secondary outcome measures included postoperative VAS scores, intraoperative anesthetic drug dosage, and adverse reactions, including nausea and vomiting, hypoxemia, and respiratory depression. RESULTS There was no significant difference in baseline data between the 2 groups (P>0.05). There was no statistically significant difference in the incidence and duration of postoperative delirium between the 2 groups (P>0.05). There were no significant differences in VAS scores, remifentanil consumption, and adverse reactions, including nausea and vomiting, hypoxemia, and respiratory depression between the 2 groups (P>0.05). CONCLUSIONS In elderly patients undergoing radical colon cancer surgery, remimazolam administration did not improve or aggravate the incidence and duration of delirium, compared with propofol.

Delirium in older adults after percutaneous coronary intervention: Prevalence, risks, and clinical phenotypes

INTRODUCTION

In-hospital delirium is more common among older adults and is associated with increased mortality and adverse health-related outcomes. We aim to establish the contemporary prevalence of delirium among older adults undergoing percutaneous coronary intervention (PCI) and the impact of delirium on in-hospital complications.

METHODS

We identified older adults aged ≥75 years in the National Inpatient Sample who underwent inpatient PCI for any reason from 2016 to 2020 and stratified them into those with and without delirium. The primary outcome was in-hospital mortality, and secondary outcomes encompassed post-procedural complications.

RESULTS

Delirium occurred in 14,130 (2.6 %) hospitalizations in which PCI was performed. Patients who developed delirium were older and had more comorbidities. Patients with in-hospital delirium had higher odds of in-hospital mortality (adjusted odds ratio [aOR] 1.27, p = 0.002) and non-home discharge (aOR 3.17, p < 0.001). Delirium was also associated with higher odds of intracranial hemorrhage (aOR 2.49, p < 0.001), gastrointestinal hemorrhage (aOR 1.25, p = 0.030), need for blood transfusion (aOR 1.52, p < 0.001), acute kidney injury (aOR 1.62, p < 0.001), and fall in hospital (aOR 1.97, p < 0.001).

CONCLUSION

Delirium among older adults undergoing PCI is relatively common and associated with higher odds of in-hospital mortality and adverse events. This highlights the importance of vigilant delirium prevention and early recognition in the peri-procedural setting, especially for older adults.

Dementia and Postoperative Delirium in Surgical Hip Fracture Patients: Unveiling Contrasting Risk Factors and Implications

Postoperative delirium is a serious complication, particularly in older adults with hip fractures. Using the 2019 American College of Surgeons National Surgical Quality Improvement Program data file, we performed multiple regression analyses to compare risk factors for postoperative delirium in hip fracture patients with and without dementia. Preoperative delirium and mobility aid use were common risk factors in both groups. However, differential effects were observed for other factors. Pathological fracture increased delirium risk in patients with dementia but had a protective effect in those without dementia. In patients with dementia, American Society of Anesthesiology score IV/V was identified as a risk factor, whereas advanced age, severe chronic obstructive pulmonary disease, weight loss, sepsis, elevated international normalized ratio, and serum creatinine level were additional risk factors in patients without dementia. These findings enhance our understanding of the complex relationship among dementia, hip fractures, and postoperative delirium. Identifying specific risk factors for each group can inform tailored interventions and preventive strategies. Further research is needed to validate and expand these findings, ultimately improving care and outcomes. [Journal of Gerontological Nursing, 49(12), 25-30.].

Intestinal microbiota: a new perspective on delaying aging?

The global aging situation is severe, and the medical pressures associated with aging issues should not be underestimated. The need and feasibility of studying aging and intervening in aging have been confirmed. Aging is a complex natural physiological progression, which involves the irreversible deterioration of body cells, tissues, and organs with age, leading to enhanced risk of disease and ultimately death. The intestinal microbiota has a significant role in sustaining host dynamic balance, and the study of bidirectional communication networks such as the brain-gut axis provides important directions for human disease research. Moreover, the intestinal microbiota is intimately linked to aging. This review describes the intestinal microbiota changes in human aging and analyzes the causal controversy between gut microbiota changes and aging, which are believed to be mutually causal, mutually reinforcing, and inextricably linked. Finally, from an anti-aging perspective, this study summarizes how to achieve delayed aging by targeting the intestinal microbiota. Accordingly, the study aims to provide guidance for further research on the intestinal microbiota and aging.

Preventing and treating delirium in clinical settings for older adults

Delirium is a serious consequence of many acute or worsening chronic medical conditions, a side effect of medications, and a precipitant of worsening functional and cognitive status in older adults. It is a syndrome characterized by fluctuations in cognition and impaired attention that develops over a short period of time in response to an underlying medical condition, a substance (prescribed, over the counter, or recreational), or substance withdrawal and can be multi-factorial. We present a narrative review of the literature on nonpharmacologic and pharmacologic approaches to prevention and treatment of delirium with a focus on older adults as a vulnerable population. Older adult patients are most at risk due to decreasing physiologic reserves, with delirium rates of up to 80% in critical care settings. Presentation of delirium can be hyperactive, hypoactive, or mixed, making identification and study challenging as patients with hypoactive delirium are less likely to come to attention in an inpatient or long-term care setting. Studies of delirium focus on prevention and treatment with nonpharmacological or medication interventions, with the preponderance of evidence favoring multi-component nonpharmacological approaches to prevention as the most effective. Though use of antipsychotic medication in delirium is common, existing evidence does not support routine use, showing no clear benefit in clinically significant outcome measures and with evidence of harm in some studies. We therefore suggest that antipsychotics be used to treat agitation, psychosis, and distress associated with delirium at the lowest effective doses and shortest possible duration and not be considered a treatment of delirium itself. Future studies may clarify the use of other agents, such as melatonin and melatonin receptor agonists, alpha-2 receptor agonists, and anti-epileptics.

Lipopolysaccharide-Induced Delirium-like Behaviour in a Rat Model of Chronic Cerebral Hypoperfusion Is Associated with Increased Indoleamine 2,3-Dioxygenase Expression and Endotoxin Tolerance

Indoleamine 2,3-dioxygenase (IDO) and the tryptophan-kynurenine pathway (TRP-KP) are upregulated in ageing and could be implicated in the pathogenesis of delirium. This study evaluated the role of IDO/KP in lipopolysaccharide (LPS)-induced delirium in an animal model of chronic cerebral hypoperfusion (CCH), a proposed model for delirium. CCH was induced by a permanent bilateral common carotid artery ligation (BCCAL) in Sprague Dawley rats to trigger chronic neuroinflammation-induced neurodegeneration. Eight weeks after permanent BCCAL, the rats were treated with a single systemic LPS. The rats were divided into three groups: (1) post-BCCAL rats treated with intraperitoneal (i.p.) saline, (2) post-BCCAL rats treated with i.p. LPS 100 μg/kg, and (3) sham-operated rats treated with i.p. LPS 100 μg/kg. Each group consisted of 10 male rats. To elucidate the LPS-induced delirium-like behaviour, natural and learned behaviour changes were assessed by a buried food test (BFT), open field test (OFT), and Y-maze test at 0, 24-, 48-, and 72 h after LPS treatment. Serum was collected after each session of behavioural assessment. The rats were euthanised after the last serum collection, and the hippocampi and cerebral cortex were collected. The TRP-KP neuroactive metabolites were measured in both serum and brain tissues using ELISA. Our data show that LPS treatment in CCH rats was associated with acute, transient, and fluctuated deficits in natural and learned behaviour, consistent with features of delirium. These behaviour deficits were mild compared to the sham-operated rats, which exhibited robust behaviour impairments. Additionally, heightened hippocampal IDO expression in the LPS-treated CCH rats was associated with reduced serum KP activity together with a decrease in the hippocampal quinolinic acid (QA) expression compared to the sham-operated rats, suggested for the presence of endotoxin tolerance through the immunomodulatory activity of IDO in the brain. These data provide new insight into the underlying mechanisms of delirium, and future studies should further explore the role of IDO modulation and its therapeutic potential in delirium.

Persistent Postoperative Delirium Following Laparoscopic Cholecystectomy

Gallstones are the primary cause of symptomatic gallbladder disease and lead to a significant portion of hospitalizations related to gastrointestinal diseases. The gold standard treatment for gallbladder disease continues to be cholecystectomy, which is commonly done laparoscopically, and improves patients' quality of life. With any surgical intervention there are inherent risks, and in the setting of severe illness, the risk of potential complications increases immensely. Postoperative altered mental status, namely, delirium, may occur in the elderly and a high index of suspicion is required to recognize the clinical signs for swift diagnosis and management. This case involves a 61-year-old male who underwent laparoscopic cholecystectomy and developed persistent delirium during the hospital course. This report aims to explore the multiple risk factors that lead to postoperative delirium and review the diagnostic and therapeutic strategies utilized in managing this patient.

The nomogram to predict the occurrence of sepsis-associated encephalopathy in elderly patients in the intensive care units: A retrospective cohort study

Background

Sepsis-associated encephalopathy (SAE) is a critical and common problem in elderly patients with sepsis, which is still short of efficient predictive tools. Therefore, this study aims to screen the risk factors and establish a useful predictive nomogram for SAE in elderly patients with sepsis in the intensive care unit (ICU).

Patients and methods

Elderly patients (age ≥ 65 years) with sepsis were selected from the Medical Information Mart for Intensive Care (MIMIC)-IV database. Data from demographics and laboratory examinations were collected on the first day of admission to the ICU. SAE was defined by two criteria in the presence of sepsis: ① a Glasgow Coma Scale (GCS) score of < 15 or ② delirium. Differences in demographics and laboratory tests were calculated between SAE and non-SAE groups. Participants were randomly divided into a training set and a validation set without replacement at a ratio of 6:4. A predictive nomogram was constructed in the training set by logistic regression analysis and then validated. The predictive capability of the nomogram was demonstrated by receiver operating characteristic (ROC) analysis and calibration curve analysis.

Results

A total of 22,361 patients were selected, of which 2,809 patients (12.7%) died in the hospital and 8,290 patients (37.1%) had SAE. In-hospital mortality in the SAE group was higher than that in the non-SAE group (18.8 vs. 8.9%, p < 0.001). Based on the results of logistic regression analysis, a nomogram integrating age, Na⁺, Sequential Organ Failure Assessment (SOFA) score, heart rate, and body temperature were constructed. The area under the curve (AUC) of the nomogram was 80.2% in the training set and 80.9% in the validation set. Calibration curve analysis showed a good predictive capacity of the nomogram.

Conclusion

SAE is an independent risk of in-hospital mortality in elderly patients in the intensive care unit. The nomogram has an excellent predictive capability of SAE and helps in clinical practice.

Incidence and interaction factors of delirium as an independent risk of mortality in elderly patients in the intensive units: a retrospective analysis from MIMIC-IV database

BACKGROUND

As delirium is a common problem in critcal elderly patients, the aim of the study was to investigate the interaction factors of delirium as an independent risk of mortality in elderly patients in the intensive care unit (ICU).

PATIENTS AND METHODS

Elderly patients (age ≥ 65) were selected from Medical Information Mart for Intensive Care (MIMIC)-IV database. Demographics data were collected on the 1st day of admission to ICU. The main outcome is in-hospital mortality. Propensity score matching analysis (PSMA) was used to remove the influence of comfounding factors between survival and nonsurvival groups. Chi-square test and logistic regression analysis was used to identify the association between delirium and in-hospital death. Stratified analysis and interaction analysis was used to evaluate the interaction factors of delirium as a risk of in-hospital mortality.

RESULTS

22,361 patients were selected, and in which 2809 patients died. 5453 patients had delirium (about 24.4%). There is a significant difference in delirium between the survival and nonsurvival groups before and after PSMA (p = 0.000 and p = 0.030). Logistic regression showed delirium, sequential organ failure assessment (SOFA), and hemoglobin were all significantly related to in-hospital death (p = 0.000). SOFA score and hemoglobin concentration were proved to be remarkable interaction factors of delirium (p = 0.000, and p = 0.041). Significant correlation between delirium and hospital mortality was inhibited when SOFA was more than 12 or hemoglobin was higher than 15 g/dL. In-hospital mortality (49.1% vs. 10.5%, p = 0.000) and shock incidence (87.9% vs. 15.8%, p = 0.000) of the patients with SOFA ≥ 12 was much higher than that of the patients with SOFA ≤ 11.

CONCLUSION

SOFA and hemoglobin are interaction factors of delirium as an independent risk of in-hospital mortality in elderly patients in the intensive care unit.

Pathogenesis of sepsis-associated encephalopathy: more than blood-brain barrier dysfunction

Sepsis-associated encephalopathy is a common neurological complication of sepsis and is responsible for higher mortality and poorer long-term outcomes in septic patients. Sepsis-associated encephalopathy symptoms can range from mild delirium to deep coma, which occurs in up to 70% of patients in intensive care units. The pathological changes in the brain associated with sepsis include cerebral ischaemia, cerebral haemorrhage, abscess and progressive multifocal necrotic leukoencephalopathy. Several mechanisms are involved in the pathogenesis of sepsis-associated encephalopathy, such as blood-brain barrier dysfunction, cerebral blood flow impairment, glial cell activation, leukocyte transmigration, and neurotransmitter disturbances. These events are interrelated and influence each other, therefore they do not act as independent factors. This review is focused on new evidence showing the pathological process of sepsis-associated encephalopathy.

Melatonin and Its Analogs for Prevention of Post-cardiac Surgery Delirium: A Systematic Review and Meta-Analysis

Background

The effectiveness of melatonin and its analogs in preventing postoperative delirium (POD) following cardiac surgery is controversial. The purpose of this systematic review and meta-analysis was to confirm the benefits of melatonin and its analogs on delirium prevention in adults who underwent cardiac surgery.

Methods

We systematically searched the PubMed, Cochrane Library, Web of Science, Embase, and EBSCOhost databases, the last search was performed in October 2021 and repeated before publication. The controlled studies were included if investigated the impact of melatonin and its analogs on POD in adults who underwent cardiac surgery. The primary outcome was the incidence of delirium. The Stata statistical software 17.0 was used to perform this study.

Results

This meta-analysis included eight randomized controlled trials (RCTs) and two cohort studies with a total of 1,714 patients. The results showed that melatonin and ramelteon administration were associated with a significantly lower incidence of POD in adults who underwent cardiac surgery (odds ratio [OR], 0.46; 95% confidence interval [CI], 0.29–0.74; P = 0.001). The subgroup analyses confirmed that melatonin 3 mg (OR, 0.37; 95% CI, 0.18–0.76; P = 0.007) and 5 mg (OR, 0.34; 95% CI, 0.21–0.56; P < 0.001) significantly reduced the incidence of POD.

Conclusion

Melatonin at dosages of 5 and 3 mg considerably decreased the risk of delirium in adults who underwent cardiac surgery, according to our results. Cautious interpretation of our results is important owing to the modest number of studies included in this meta-analysis and the heterogeneity among them.

Systematic Review Registration

PROSPERO registration number: CRD42021246984.

Structured delirium management in the hospital—a randomized controlled trial

BACKGROUND

Delirium is a common and serious complication of inpatient hospital care in older patients. The current approaches to prevention and treatment followed in German hospitals are inconsistent. The aim of this study was to test the effectiveness of a standardized multiprofessional approach to the management of delirium in inpatients.

METHODS

The patients included in the study were all >65 years old, were treated for at least 3 days on an internal medicine, trauma surgery, or orthopedic ward at Münster University Hospital between January 2016 and December 2017, and showed cognitive deficits on standardized screening at the time of admission (a score of ≤=25 on the Montreal Cognitive Assessment [MoCA] test). Patients in the intervention group received standardized delirium prevention and treatment measures; those in the control group did not. The primary outcomes measured were the incidence and duration of delirium during the hospital stay; the secondary outcomes measured were cognitive deficits relevant to daily living at 12 months after discharge (MoCA and Instrumental Activities of Daily Living [I-ADL]).

RESULTS

The data of 772 patients were analyzed. Both the rate and the duration of delirium were lower in the intervention group than in the control group (6.8% versus 20.5%, odds ratio 0.28, 95% confidence interval [0.18; 0.45]; 3 days [interquartile range, IQR 2-4] versus 6 days [IQR 4-8]). A year after discharge, the patients with delirium in the intervention group showed fewer cognitive deficits relevant to daily living than those in the control group (I-ADL score 2.5 [IQR 2-4] versus 1 [IQR 1-2], P = 0.02).

CONCLUSION

Structured multiprofessional management reduces the incidence and duration of delirium and lowers the number of lasting cognitive deficits relevant to daily living after hospital discharge.

Blood-Based Biomarkers of Neuroinflammation in Alzheimer's Disease: A Central Role for Periphery?

Neuroinflammation represents a central feature in the development of Alzheimer’s disease (AD). The resident innate immune cells of the brain are the principal players in neuroinflammation, and their activation leads to a defensive response aimed at promoting β-amyloid (Aβ) clearance. However, it is now widely accepted that the peripheral immune system—by virtue of a dysfunctional blood–brain barrier (BBB)—is involved in the pathogenesis and progression of AD; microglial and astrocytic activation leads to the release of chemokines able to recruit peripheral immune cells into the central nervous system (CNS); at the same time, cytokines released by peripheral cells are able to cross the BBB and act upon glial cells, modifying their phenotype. To successfully fight this neurodegenerative disorder, accurate and sensitive biomarkers are required to be used for implementing an early diagnosis, monitoring the disease progression and treatment effectiveness. Interestingly, as a result of the bidirectional communication between the brain and the periphery, the blood compartment ends up reflecting several pathological changes occurring in the AD brain and can represent an accessible source for such biomarkers. In this review, we provide an overview on some of the most promising peripheral biomarkers of neuroinflammation, discussing their pathogenic role in AD.