Postoperative delirium risk in patients with hyperlipidemia: A prospective cohort study

STUDY OBJECTIVE

Hyperlipidemia and postoperative delirium (POD) significantly affect patients' quality of life; however, the question of whether hyperlipidemia constitutes a risk factor for POD remain unclear. This study aimed to investigate whether patients with hyperlipidemia face elevated risks of developing POD and to identify potential causes for this increased risk.

DESIGN

A prospective cohort study.

SETTING

Operating room.

PATIENTS

Patients were adults scheduled for colorectal cancer surgery in 2023.

EXPOSURES

The exposure factor was hyperlipidemia, and the patients were divided into hyperlipidemia group and non-hyperlipidemia group.

MEASUREMENTS

POD occurrence within three days post-surgery was assessed using the 3-Minute Diagnostic Interview for Confusion Assessment Method. Over one year, these patients were monitored through telephone to evaluate their survival and cognitive function. Logistic regression analysis was performed to evaluate the risk factors for POD development in patients with hyperlipidemia and to construct a clinical prediction model.

MAIN RESULTS

This study included 555 patients. POD incidence was 21.6% in the hyperlipidemia group and 12.7% in the non-hyperlipidemia group. One year following surgery, patients with hyperlipidemia and POD exhibited significantly higher rates of mortality and cognitive decline than did those without POD (p < 0.001). A multifactorial logistic clinical prediction model was constructed from seven independent risk factors for POD development in patients with hyperlipidemia, including education, preoperative total cholesterol (TC), preoperative triglyceride (TG), diet, history of hypertension, Sedation-Agitation Scale, and postoperative trimethylamine N-oxide expression level, and it had the highest predictive value for POD development in patients with hyperlipidemia.

CONCLUSIONS

Compared with those without hyperlipidemia, patients with hyperlipidemia had higher POD incidence. Elevated serum TC and TG levels are independent risk factors for POD in patients with hyperlipidemia. The study's findings could help develop strategies for improving POD and hyperlipidemia treatment.

Postoperative cognitive disorders and delirium in gynecologic surgery: Which surgery and anesthetic techniques to use to reduce the risk?

Despite their general good health, an increasing proportion of elderly individuals require surgery due to an increase in average lifespan. However, because of their increased vulnerability, these patients need to be handled carefully to make sure that surgery does not cause more harm than good. Age-related postoperative cognitive disorders (POCD) and postoperative delirium (POD), two serious consequences that are marked by adverse neuropsychologic alterations after surgery, are particularly dangerous for the elderly. In the context of gynecologic procedures, POCD and POD are examined in this narrative review. The main question is how to limit the rates of POCD and POD in older women undergoing gynecologic procedures by maximizing the risk-benefit balance. Three crucial endpoints are considered: (1) surgical procedures to lower the rates of POCD and POD, (2) anesthetic techniques to lessen the occurrence and (3) the identification of individuals at high risk for post-surgery cognitive impairments. Risks associated with laparoscopic gynecologic procedures include the Trendelenburg posture and CO2 exposure during pneumoperitoneum, despite statistical similarities in POD and POCD frequency between laparoscopic and laparotomy techniques. Numerous risk factors are associated with surgical interventions, such as blood loss, length of operation, and position holding, all of which reduce the chance of complications when they are minimized. In order to emphasize the essential role that anesthesia and surgery play in patient care, anesthesiologists are vital in making sure that anesthesia is given as sparingly and quickly as feasible. In addition, people who are genetically predisposed to POCD may be more susceptible to the disorder. The significance of a thorough strategy combining surgical and anesthetic concerns is highlighted in this article, in order to maximize results for senior patients having gynecologic surgery.

Early and Long-Term Results of Simultaneous and Staged Revascularization of Coronary and Carotid Arteries

BACKGROUND

Carotid artery disease is prevalent among patients with coronary heart disease. The concomitant severe lesions in the carotid and coronary arteries may necessitate either simultaneous or staged revascularization involving coronary bypass and carotid endarterectomy. However, there is presently a lack of consensus on the optimal choice of surgical treatment tactics for patients with significant stenoses in both carotid and coronary arteries. The aim of the current study was to compare the 30-day and long-term outcomes of coronary and carotid artery revascularization surgery based on the simultaneous or staged surgical tactics.

MATERIAL AND METHODS

This single-center retrospective study involved 192 patients with concurrent coronary artery disease and carotid artery stenosis ≥ 70%, of whom 106 patients underwent simultaneous intervention (CABG + CEA) and 86 patients underwent staged CABG/CEA. The mean time between stages ranged from 1 to 4 months (mean 1.88 ± 0.9 months). The endpoints included death from any cause, non-fatal stroke, non-fatal myocardial infarction (MI), and major adverse cardiovascular events (MACEs) (death + non-fatal MI + non-fatal stroke) within 30 days after the last intervention and in the long-term follow-up period (median follow-up-6 years).

RESULTS

The 30-day all-cause mortality, incidence of postoperative non-fatal MI, non-fatal stroke, and MACEs did not exhibit differences between the groups after single-stage and staged interventions. However, the overall risk of postoperative complications (adjusted for the risk of any complication per patient) (OR 2.214, 95% CI 1.048-4.674, p = 0.035), as well as the duration of ventilatory support (p = 0.004), was elevated in the group after simultaneous interventions compared with the staged intervention group. This difference did not result in an increased incidence of death and MACEs in the group after simultaneous interventions. In the long-term follow-up period, there were no significant differences observed when comparing simultaneous or staged surgical tactics in terms of overall survival (54.9% and 62.6% in Groups 1 and 2, respectively, P log-rank = 0.068), non-fatal stroke-free survival (45.6% and 33.6% in Groups 1 and 2, respectively, P log-rank = 0.364), non-fatal MI-survival (57.6% and 73.5% in Groups 1 and 2, respectively, P log-rank = 0.169), and MACE-free survival (7.1% and 30.2% in Groups 1 and 2, respectively, P log-rank = 0.060). The risk factors associated with an unfavorable outcome included age, smoking, BMI, LV EF, and atherosclerosis of the lower extremity arteries.

CONCLUSIONS

This study revealed no significant difference in the impact of simultaneous CABG + CEA or staged CABG/CEA on the incidence of death, stroke, MI, and MACEs over a 30-day and long-term follow-up period. Although the immediate results indicated an increased risk of a complicated course (attributable to overall complications) and more prolonged ventilation after simultaneous CABG + CEA compared with staged CABG/CEA, this did not lead to an increase in fatal complications. Therefore, the implementation of either tactic is considered eligible and appropriate following a thorough operative risk assessment.

Online interpretable dynamic prediction models for postoperative delirium after cardiac surgery under cardiopulmonary bypass developed based on machine learning algorithms: A retrospective cohort study

OBJECTIVE

Postoperative delirium (POD) is strongly associated with poor early and long-term prognosis in cardiac surgery patients with cardiopulmonary bypass (CPB). This study aimed to develop dynamic prediction models for POD after cardiac surgery under CPB using machine learning (ML) algorithms.

METHODS

From July 2021 to June 2022, clinical data were collected from patients undergoing cardiac surgery under CPB at Nanjing First Hospital. A dataset from the same center (October 2022 to November 2022) was also used for temporal external validation. We used ML and deep learning to build models in the training set, optimized parameters in the test set, and finally validated the best model in the validation set. The SHapley Additive exPlanations (SHAP) method was introduced to explain the best models.

RESULTS

Of the 885 patients enrolled, 221 (25.0%) developed POD. 22 (22.0%) of 100 validation cohort patients developed POD. The preoperative and postoperative artificial neural network (ANN) models exhibited optimal performance. The validation results demonstrated satisfactory predictive performance of the ANN model, with area under the receiver operator characteristic curve (AUROC) values of 0.776 and 0.684 for the preoperative and postoperative models, respectively. Based on the ANN algorithm, we constructed dynamic, highly accurate, and interpretable web risk calculators for POD.

CONCLUSIONS

We successfully developed online interpretable dynamic ANN models as clinical decision aids to identify patients at high risk of POD before and after cardiac surgery to facilitate early intervention or care.

Perioperative neurocognitive disorder changes in elderly diabetes patients within 30 days after surgery: a retrospective cohort study

BACKGROUND

Perioperative neurocognitive disorders (PND) are a common central nervous system complication that predominantly affects the elderly. PND after surgery includes postoperative delirium (POD), delayed neurocognitive recovery up to 30 days (DNR), and postoperative neurocognitive disorder up to 12 months. Diabetes is an important independent risk factor for PND. Over the years, few studies have assessed the incidence of PND and the difference in serum biomarkers between diabetic and non-diabetic patients. We sought to examine the difference in the incidence of PND between elderly diabetic and non-diabetic patients in China and identify the risk factors of PND in elderly diabetics.

METHODS

We conducted a secondary and exploratory data analysis from our prior studies, including patients aged 65 years or older who underwent non-cardiac elective surgery with general anesthesia. We used the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) and Montreal Cognitive Assessment (MoCA) to assess patient cognition.

RESULTS

A total of 236 patients were analyzed; the incidence of PND was significantly higher in diabetic than in non-diabetic patients within 30 days (59.2% vs. 36.8%) (P = 0.022). Multivariate logistic regression analysis showed that the preoperative MoCA was an independent risk factor for PND (odds ratio, 0.88 [0.8 to 0.97]; P = 0.014), and Hosmer-Lemeshow tests showed that it could predict PND in diabetic patients (P = 0.360). According to the maximum Youden index, the optimal cutoff for preoperative MoCA was 21.5 points, yielding a specificity and sensitivity of 88.0% and 55.2% for PND. The levels of glial fibrillary acidic protein (GFAP) and Tau in diabetic patients before and after surgery were significantly higher than in non-diabetic patients among cases of PND (P = 0.002 and 0.011, respectively).

CONCLUSION

The incidence of PND is higher in diabetic than in non-diabetic patients in China, and preoperative MoCA is an independent risk factor for PND in diabetics. Meanwhile, the changes in GFAP and p-Tau in diabetic patients who experienced PND were significantly higher than in non-diabetic ones.

Depletion of PIEZO1 expression is accompanied by upregulating p53 signaling in mice with perioperative neurocognitive disorder

As the common complications observed in surgical elder patients, perioperative neurocognitive disorders (PND) cause a series of serious perioperative health problems. However, there are no effective treatments, and the exact mechanisms are still largely unknown. In this study, transcriptome sequencing was performed to investigate the differentially expressed genes (DEGs) in the hippocampus of C57BL/6J aged mice with or without PND. Compared with the Mock group, the expression of 352, 395, and 772 genes changed significantly in the PND group at days 1, 7, and 21 after surgery, respectively. Gene ontology (GO) and gene set enrichment analysis (GSEA) showed that DEGs were mainly associated with p53 signaling. Moreover, GSEA revealed potentially p53-related DEGs such as leucine-rich repeat serine/threonine-protein kinase 1 (LRRK1), monooxygenase DBH-like 1 (MOXD1), and piezo type mechanosensitive ion channel component 1 (PIEZO1). Furthermore, we confirmed the decreased interaction of PIEZO1 with p53 in PND, and upregulation of PIEZO1 resulted in a decrease in p53 protein levels through increased ubiquitination of p53. In conclusion, this study contributes to the knowledge of global changes in gene expression and mechanisms during PND.

Data Science and Geriatric Anesthesia Research: Opportunity and Challenges

With an increase in geriatric population undergoing surgical procedures, research focused on enhancing their perioperative outcomes is of paramount importance. Currently, most of the evidence-based medicine protocols are driven by studies concentrating on adults encompassing all adult age groups. Given the alterations in physiology with aging, geriatric patients respond differently to anesthetics and, therefore, require specific research initiatives to further expound on the same. Large databases and the development of sophisticated analytic tools can provide meaningful insights into this. Here, we discuss a few research opportunities and challenges that data scientists face when focusing on geriatric perioperative research.

Dexmedetomidine after deep brain stimulation for prevention of delirium in elderly patients with Parkinson's disease: protocol for a single-centre, randomised, double-blind, placebo-controlled trial in China

INTRODUCTION

Parkinson's disease is one of the most common neurodegenerative diseases. Deep brain stimulation (DBS) can improve motor symptoms in patients with middle and late Parkinson's disease, reduce the use of levodopa, and thus reduce drug-related side effects. Postoperative delirium can significantly reduce the short-term and long-term quality of life in elderly patients, which can be alleviated by dexmedetomidine (DEX). However, whether prophylactic DEX could reduce the incidence of postoperative delirium in patients with Parkinson's disease was still unknown.

METHODS AND ANALYSIS

This is a single-centre, randomised, double-blinded, placebo-controlled group trial. A total of 292 patients aged 60 years and above elected for DBS will be stratified according to DBS procedure, subthalamic nucleus or globus pallidus interna, then randomly allocated to the DEX group or the placebo control group with a 1:1 ratio, respectively. In the DEX group, patients will be injected with the DEX continuously with an electronic pump at a rate of 0.1 µg/kg/hour for 48 hours at the beginning of general anaesthesia induction. In the control group, normal saline will be administered at the same rate for patients as in the DEX group. The primary endpoint is the incidence of postoperative delirium within 5 days after surgery. Postoperative delirium is assessed by the combination of the Richmond Anxiety Scale and the Confusion Assessment Method (CAM) for the intensive care unit or the 3-minute diagnostic interview for CAM as applicable. The secondary endpoints include the incidence of adverse events and non-delirium complications, the length of stay in the intensive care unit and hospital and all-cause 30-day mortality after the operation.

ETHICS AND DISSEMINATION

The protocol has been approved by the Ethics Committee of Beijing Tiantan Hospital of Capital Medical University (KY2022-003-03). The results of this study will be disseminated through presentation at scientific conferences and publication in scientific journals.

TRIAL REGISTRATION NUMBER

NCT05197439.

Risk factors for delayed neurocognitive recovery in elderly patients undergoing thoracic surgery

BACKGROUND

To investigate the risk factors for delayed neurocognitive recovery in elderly patients undergoing thoracic surgery.

METHODS

A total of 215 elderly patients who underwent thoracic surgery between May 2022 and October 2022 were recruited in this prospective observational study. Cognitive function was tested by MoCA tests that were performed by the same trained physician before surgery, on postoperative day 4 (POD4), and on postoperative day 30 (POD30). Univariate and multivariate logistic regression models were used to analyze the risk factors for DNR.

RESULTS

A total of 154 patients (55.8% men) with an average age of 67.99 ± 3.88 years were finally included. Patients had an average preoperative MoCA score of 24.68 ± 2.75. On the 30th day after surgery, 26 (16.88%) patients had delayed postoperative cognitive recovery, and 128 (83.12%) had postoperative cognitive function recovery. Diabetes mellitus (OR = 6.508 [2.049-20.664], P = 0.001), perioperative inadvertent hypothermia (< 35℃) (OR = 5.688 [1.693-19.109], P = 0.005), history of cerebrovascular events (OR = 10.211 [2.842-36.688], P < 0.001), and VICA (sevoflurane combined with propofol anesthesia) (OR = 5.306 [1.272-22.138], P = 0.022) resulted as independent risk factors of delayed neurocognitive recovery. On the POD4, DNR was found in 61 cases (39.6%), and age ≥ 70 years (OR = 2.311 [1.096-4.876], P = 0.028) and preoperative NLR ≥ 2.5 (OR = 0.428 [0.188-0.975], P = 0.043) were identified as independent risk factors.

CONCLUSIONS

The risk factors for delayed neurocognitive recovery in elderly patients undergoing thoracic surgery include diabetes, perioperative inadvertent hypothermia (< 35℃), VICA (sevoflurane combined with propofol anesthesia), and history of cerebrovascular events.

Peri-Operative Risk Factors Associated with Post-Operative Cognitive Dysfunction (POCD): An Umbrella Review of Meta-Analyses of Observational Studies

This umbrella review aimed to systematically identify the peri-operative risk factors associated with post-operative cognitive dysfunction (POCD) using meta-analyses of observational studies. To date, no review has synthesised nor assessed the strength of the available evidence examining risk factors for POCD. Database searches from journal inception to December 2022 consisted of systematic reviews with meta-analyses that included observational studies examining pre-, intra- and post-operative risk factors for POCD. A total of 330 papers were initially screened. Eleven meta-analyses were included in this umbrella review, which consisted of 73 risk factors in a total population of 67,622 participants. Most pertained to pre-operative risk factors (74%) that were predominantly examined using prospective designs and in cardiac-related surgeries (71%). Overall, 31 of the 73 factors (42%) were associated with a higher risk of POCD. However, there was no convincing (class I) or highly suggestive (class II) evidence for associations between risk factors and POCD, and suggestive evidence (class III) was limited to two risk factors (pre-operative age and pre-operative diabetes). Given that the overall strength of the evidence is limited, further large-scale studies that examine risk factors across various surgery types are recommended.

The multifaceted role of neurofilament light chain protein in non-primary neurological diseases

The advancing validation and exploitation of CSF and blood neurofilament light chain protein as a biomarker of neuroaxonal damage has deeply changed the current diagnostic and prognostic approach to neurological diseases. Further, recent studies have provided evidence of potential new applications of this biomarker also in non-primary neurological diseases. In the present review we summarize the state of the art, future perspectives, but also limitations, of neurofilament light chain protein as a CSF and blood biomarker in several medical fields, including intensive care medicine, surgery, internal medicine and psychiatry. In particular, neurofilament light chain protein is associated with the degree of neurological impairment and outcome in patients admitted to intensive care units or in the perioperative phase and it seems to be highly interconnected with cardiovascular risk factors. Beyond that, interesting diagnostic and prognostic insights have been provided by the investigation of neurofilament light chain protein in psychiatric disorders as well as in the current coronavirus disease-19 pandemic and in normal ageing. Altogether, current data outline a multifaceted applicability of CSF and blood neurofilament light chain protein ranging from the critical clinical setting to the development of precision medicine models suggesting a strict interplay between the nervous system pathophysiology and the health-illness continuum.

Perioperative probiotics attenuates postoperative cognitive dysfunction in elderly patients undergoing hip or knee arthroplasty: A randomized, double-blind, and placebo-controlled trial

Background

Postoperative cognitive dysfunction (POCD) is a common complication in elderly patients following surgery. The preventive and/or treatment strategies for the incidence remain limited.

Objective

This study aimed to investigate the preventive effect of perioperative probiotic treatment on POCD in elderly patients undergoing hip or knee arthroplasty.

Methods

After obtaining ethical approval and written informed consent, 106 patients (age ≥60 years) were recruited, who scheduled elective hip or knee arthroplasty, from 16 March 2021 to 25 February 2022 for this randomized, double-blind, and placebo-controlled trial. They were randomly assigned with a 1:1 ratio to receive either probiotics or placebo treatment (four capsules, twice/day) from hospital admission until discharge. Cognitive function was assessed with a battery of 11 neuropsychological tests on the admission day and the seventh day after surgery, respectively.

Results

A total of 96 of 106 patients completed the study, and their data were finally analyzed. POCD occurred in 12 (26.7%) of 45 patients in the probiotic group and 29 (56.9%) of 51 patients in the placebo group (relative risk [RR], 0.47 [95% confidence interval [CI], 0.27 to 0.81]; P = 0.003). Among them, mild POCD occurred in 11 (24.4%) in the probiotic group and 24 (47.1%) in the placebo group (RR, 0.52 [95% CI, 0.29 to 0.94]; P = 0.022). No significant difference in severe POCD incidence was found between the two groups (P = 0.209). Compared with the placebo group, the verbal memory domain cognitive function was mainly improved in the probiotic group.

Conclusion

Probiotics may be used perioperatively to prevent POCD development and improve verbal memory performance in elderly patients receiving hip or knee arthroplasty.

Clinical trial registration

www.chictr.org.cn, identifier: ChiCTR2100045620.

Functional comorbidities and brain tissue changes before and after lung transplant in adults

Background

Adults undergoing lung transplant, as a lifesaving treatment for end stage lung disease, exhibit high levels of peri-operative neurocognitive dysfunction in multiple domains, including delirium, cognition, and autonomic deficits. These complications impact healthcare costs, quality of life, and patient outcomes. Post-operative symptoms likely result from loss of brain tissue integrity in sites mediating such regulatory functions. Our aim in this study was to examine peri-operative neurocognitive dysfunction and brain tissue changes after lung transplant in adults.

Methods

We retrospectively examined the UCLA lung transplant database to identify 114 lung transplant patients with pre-operative clinical and neurocognitive data. Of 114 patients, 9 lung transplant patients had pre- and post-transplant brain magnetic resonance imaging. Clinical and neurocognitive data were summarized for all subjects, and brain tissue volume changes, using T1-weighted images, before and after transplant were examined. T1-weighted images were partitioned into gray matter (GM)-tissue type, normalized to a common space, smoothed, and the smoothed GM-volume maps were compared between pre- and post-transplant (paired t-tests; covariate, age; SPM12, p &lt; 0.005).

Results

Increased comorbidities, including the diabetes mellitus (DM), hypertension, kidney disease, and sleep disordered breathing, as well as higher rates of neurocognitive dysfunction were observed in the lung transplant patients, with 41% experiencing post-operative delirium, 49% diagnosed with a mood disorder, and 25% of patients diagnosed with cognitive deficits, despite incomplete documentation. Similarly, high levels of delirium, cognitive dysfunction, and mood disorder were noted in a subset of patients used for brain MRI evaluation. Significantly decreased GM volumes emerged in multiple brain regions, including the frontal and prefrontal, parietal, temporal, bilateral anterior cingulate and insula, putamen, and cerebellar cortices.

Conclusion

Adults undergoing lung transplant often show significant pre-operative comorbidities, including diabetes mellitus, hypertension, and chronic kidney disease, as well as neurocognitive dysfunction. In addition, patients with lung transplant show significant brain tissue changes in regions that mediate cognition, autonomic, and mood functions. The findings indicate a brain structural basis for many enhanced post-operative symptoms and suggest a need for brain tissue protection in adults undergoing lung transplant to improve health outcomes.

Potential Markers of Neurocognitive Disorders After Cardiac Surgery: A Bibliometric and Visual Analysis

Background

Identifying useful markers is essential for diagnosis and prevention of perioperative neurocognitive disorders (PNDs). Here, we attempt to understand the research basis and status, potential hotspots and trends of predictive markers associated with PNDs after cardiac surgery via bibliometric analysis.

Methods

A total of 4,609 original research articles and reviews that cited 290 articles between 2001 and 2021 were obtained from the Web of Science Core Collection (WoSCC) as the data source. We used the software CiteSpace to generate and analyze visual networks of bibliographic information, including published years and journals, collaborating institutions, co-cited references, and co-occurring keywords.

Results

The number of annual and cumulative publications from 2001 to 2021 has been increasing on the whole. The Harvard Medical School was a very prolific and important institution in this field. The journal of Ann Thorac Surg (IF 4.33) had the most publications, while New Engl J Med was the most cited journal. Neuron-specific enolase (NSE), S100b and kynurenic acid (KYNA) were frequently discussed as possible markers of PNDs in many references. Cardiopulmonary bypass (CPB) was a keyword with high frequency (430) and sigma (6.26), and inflammation was the most recent burst keyword.

Conclusion

Potential markers of PNDs has received growing attention across various disciplines for many years. The research basis mainly focuses on three classic biomarkers of S100b, NSE, and KYNA. The most active frontiers are the inflammation-related biomarkers (e.g., inflammatory cells, cytokines, or mediators) and surgery-related monitoring parameters (e.g., perfusion, oxygen saturation, and the depth of anesthesia).

Effects of dexmedetomidine on cognitive dysfunction and neuroinflammation via the HDAC2/HIF-1α/PFKFB3 axis in a murine model of postoperative cognitive dysfunction

Inhibition of histone deacetylase (HDAC) may be a useful approach in the treatment of disorders characterized by cognitive dysfunction. Dexmedetomidine (DEX), an α2-adrenoceptor (α2-AR) agonist, has demonstrated neuroprotective effects. Here, we attempted to investigate the protective effects of DEX on postoperative cognitive dysfunction (POCD) involving HDAC2. Male C57BL/6 mice were selected to develop a POCD model, where HDAC2, HIF-1α, and PFKFB3 expression was quantified. DEX was administered before POCD modeling. Then the cognitive function of POCD mice was evaluated with the open field and Y-maze tests. Meanwhile, lipopolysaccharide (LPS) was employed to induce BV-2 microglial cells to simulate the inflammatory response. The contents of TNF-α, IL-6, and IL-10 were measured by enzyme-linked immunosorbent assay (ELISA) in mouse serum and BV-2 cell supernatant. Abundant expression of HDAC2, HIF-1α, and PFKFB3 was confirmed in POCD mice (p < 0.05). Cognitive dysfunction in POCD mice could be alleviated following pharmacological inhibition of HDAC2 by FK228 (p < 0.05). Mechanistically, HDAC2 upregulated HIF-1α and PFKFB3 and promoted the secretion of inflammatory factors in LPS-exposed BV-2 cells (p < 0.05). DEX attenuated neuroinflammation and the resulting cognitive dysfunction by decreasing HDAC2 expression and HIF-1α-dependent PFKFB3 upregulation in POCD mice (p < 0.05). In conclusion, DEX-regulated HDAC2 may play an inhibitory role in mice with POCD through regulation of the HIF-1α/PFKFB3 axis.

The effect of intraoperative dexmedetomidine on cognitive dysfunction after surgery: a updated meta-analysis

BACKGROUND

Postoperative cognitive dysfunction (POCD) is one of the most common. Neuroprotective effects of dexmedetomidine (DEX) are reported in previous studies but evidence regarding the POCD is still unclear. In order to gain latest evidence, the present study analyzes the outcomes of randomized controlled trials (RCTs) which utilized DEX with general anaesthesia perioperatively.

METHOD

Four online databases (PubMed, Embase, the Cochrane Library, and CNKI) were used to find relevant RCTs to conduct systematic analysis. All studies comparing the incidence of POCD or MMSE score between the DEX group and the placebo or comparator group in patients undergoing general anaesthetic surgery were eligible for inclusion. Based on the inclusion and exclusion criteria, the studies were selected. This meta-analysis was performed using odds ratios (ORs) with 95% confidence intervals (CIs) for dichotomous data and standardized mean difference (SMD) and 95% CIs for continuous data as effective measures.

RESULTS

In total of 21 studies were included in this meta-analysis. The results showed that the incidence of POCD in DEX group was significantly lower than the control group on the first (OR = 0.36, 95% CI 0.24-0.54),third (OR = 0.45,95% CI 0.33-0.61) and seventh (OR = 0.40,95% CI 0.26-0.60) postoperative days; the MMSE scores in DEX group were higher than the control group on the first (SMD = 1.24, 95% CI 1.08-1.41), third(SMD = 1.09, 95%CI 0.94-1.24) and seventh (SMD = 3.28, 95% CI 1.51-5.04) postoperative days.

CONCLUSIONS

Intraoperative DEX use can ameliorate the POCD of patients who received surgical operations under general anesthesia, and effectively reduce the incidence of POCD and improve MMSE score.

Incidence, risk factors, and consequences of emergence delirium after elective brain tumor resection

BACKGROUND

Emergence delirium (ED) is a common phenomenon occurring in the recovery period. The aim of this study was to investigate the incidence, risk factors, and consequences of ED in adults after elective brain tumor resection.

METHODS

We retrospectively analyzed the data of a prospective cohort performed in a tertiary university hospital. Adult patients admitted to the intensive care unit (ICU) immediately after elective brain tumor resection were consecutively enrolled. Level of consciousness was assessed using the Richmond Agitation-Sedation Scale and ED was assessed using the Confusion Assessment Method for the ICU. Risk factors for ED were determined by multivariable logistic regression.

RESULTS

A total of 659 patients met the inclusion criteria, of which 41 patients with coma were excluded. Among the remaining 618 patients, 131 (21.2%) developed ED. Independent risk factors for ED were: age, education level, use of anticholinergic and mannitol, Glasgow Coma Score and arterial partial pressure of oxygen postoperatively, postoperative pain, malignant tumor, and frontal approach craniotomy. ED was associated with increased postoperative delirium, longer length of hospital stay, and higher hospitalization costs. There was no significant difference in the neurological function deficits (modified Rankin Scale score) between ED and non-ED groups.

CONCLUSIONS

ED has a high incidence and is associated with poor outcomes in adults after elective brain tumor resection. Early screening and prevention for ED should be established in perioperative management of this population.

κ-Opioid Receptor Agonist Ameliorates Postoperative Neurocognitive Disorder by Activating the Ca2+/CaMKII/CREB Pathway

Objective

Cardiopulmonary bypass (CPB) is an important cardiac operation and also a high-risk procedure, leading to postoperative neurocognitive disorder. However, there are few effective drugs to treat the aftermath of CPB. Therefore, we observe the effect of kappa opioid receptor (KOR) agonist on cognitive disorders of rats after cardiopulmonary bypass (CPB) and investigate the mechanism of the Ca²⁺/calmodulin-dependent protein kinase (CaMKII)/cAMP responsive element-binding protein (CREB) pathway.

Methods

A total of 40 Sprague Dawley rats were randomly divided into the sham operation group (sham group, n = 10), CPB model group (CPB group, n = 10), CPB + KOR agonist U50488H group (UH group, n = 10), and CPB + specific CaMKII antagonist + U50488H group (CKU group, n = 10). The changes in the rats' cognitive function were evaluated using the Morris water maze, the hippocampal histopathological changes were observed via hematoxylin-eosin (H&E) staining, and the apoptosis rate of neuronal cells was detected through terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining. Moreover, enzyme-linked immunosorbent assay (ELISA) was applied to examine the changes in brain injury markers, inflammatory factors, and oxidative stress factors. The hippocampal variations in Ca²⁺ concentration and oxidative stress index (ROS) levels were measured by immunofluorescence staining, and western blotting was performed to determine the expression changes in the Ca²⁺/CaMKII/CREB pathway.

Results

The KOR agonist could shorten latency, increase the swimming distance and residence time in the target quadrant, and ameliorate postoperative neurocognitive disorder (PND). Meanwhile, the KOR agonist relieved CPB-induced hippocampal and oxidative stress injuries, reduced NSE and S-100β expression, decreased the apoptosis rate, and repressed the inflammatory response, which alleviated the brain injury. In addition, U50488H was able to decrease Ca²⁺ influx and glutamate (Glu) level, inhibit N-methyl-D-aspartate receptor (NMDAR) expression, upregulate CaMKII expression, promote CREB phosphorylation, and increase the brain-derived neurotrophic factor (BDNF) level in CPB rats. However, the protective effects of KORs against PND were suppressed following the application of the CaMKII-specific antagonist.

Conclusion

The KOR agonist activates the Ca²⁺/CaMKII/CREB pathway, which improves the brain injury and relieves PND in CPB rats.

Dexmedetomidine Ameliorates Postoperative Cognitive Dysfunction via the MicroRNA-381-Mediated EGR1/p53 Axis

Postoperative cognitive dysfunction (POCD; cognitive change associated with anesthesia and surgery) is one of the most serious long-term postoperative complications that occur in elderly patients. Dexmedetomidine (DEX) has been shown to be beneficial for improving outcomes of postoperative cognitive function. However, the exact mechanism underlying this role requires is yet to be found. The present study aims to determine the pathways involved in the protective effects of DEX against POCD in C57BL/6 J aged mice. DEX was administered after POCD modeling in C57BL/6 J aged mice. The cognitive function was evaluated after DEX treatment using novel object recognition, open field, and Y-maze tests. We also assessed its effects on neuron apoptosis and production of TNF-α and IL-1β in mouse brain tissues as well as expression levels of DNA damage-related proteins p53, p21, and γH2AX. Interactions between early growth response 1 (EGR1) and p53, microRNA (miR)-381, and EGR1 were identified by ChIP and luciferase reporter assays, and gain- and loss-of-function experiments were performed to confirm the involvement of their interaction in POCD. DEX administration attenuated hippocampal neuron apoptosis, neuroinflammation, DNA damage, and cognitive impairment in aged mice. miR-381 targeted EGR1 and disrupted its interaction with p53, leading to a decline in hippocampal neuron apoptosis, DNA damage, neuroinflammation, and cognitive impairment. Furthermore, DEX administration resulted in the enhancement of miR-381 expression and the subsequent inhibition of EGR1/p53 to protect against cognitive impairment in aged mice. Overall, these results indicate that DEX may have a potential neuroprotective effect against POCD via the miR-381/EGR1/p53 signaling, shedding light on the mechanisms involved in neuroprotection in POCD.

[Near-infrared spectroscopy : Technique, development, current use and perspectives]

Near-infrared spectroscopy (NIRS) has been available in research and clinical practice for more than four decades. Recently, there have been numerous publications and substantial developments in the field. This article describes the clinical application of NIRS in relation to current guidelines, with a focus on pediatric and cardiac anesthesia. It discusses technical and physiological principles, pitfalls in clinical use and presents (patho)physiological influencing factors and derived variables, such as fractional oxygen extraction (FOE) and the cerebral oxygen index (COx). Recommendations for the interpretation of NIRS values in connection with influencing factors, such as oxygen transport capacity, gas exchange and circulation as well as an algorithm for cardiac anesthesia are presented. Limitations of the method and the lack of comparability of values from different devices as well as generally accepted standard values are explained. Technical differences and advantages compared to pulse oxymetry and transcranial Doppler sonography are illuminated. Finally, the prognostic significance and requirements for future clinical studies are discussed.

Perioperative neurocognitive dysfunction: thinking from the gut?

With the aging of the world population, and improvements in medical and health technologies, there are increasing numbers of elderly patients undergoing anaesthesia and surgery. Perioperative neurocognitive dysfunction has gradually attracted increasing attention from academics. Very recently, 6 well-known journals jointly recommended that the term perioperative neurocognitive dysfunction (defined according to the Diagnostic and Statistical Manual of Mental Disorders, fifth edition) should be adopted to improve the quality and consistency of academic communications. Perioperative neurocognitive dysfunction currently includes preoperatively diagnosed cognitive decline, postoperative delirium, delayed neurocognitive recovery, and postoperative cognitive dysfunction. Increasing evidence shows that the gut microbiota plays a pivotal role in neuropsychiatric diseases, and in central nervous system functions via the microbiota-gut-brain axis. We recently reported that abnormalities in the composition of the gut microbiota might underlie the mechanisms of postoperative cognitive dysfunction and postoperative delirium, suggesting a critical role for the gut microbiota in perioperative neurocognitive dysfunction. This article therefore reviewed recent findings on the linkage between the gut microbiota and the underlying mechanisms of perioperative neurocognitive dysfunction.

Evaluation of the risk factors for neurological and neurocognitive impairment after selective cerebral perfusion in thoracic aortic surgery

PURPOSE

Neurologic complications are seen often after the surgery of the thoracic aorta that uses selective antegrade cerebral perfusion. The objective of this study was to evaluate the impact of atherosclerotic risk factors on neurologic complications in patients who underwent surgery to the thoracic aorta using SCP.

METHODS

Data were collected retrospectively on 94 patients who underwent elective ascending aorta/aortic arch replacement. Concomitant procedures were performed as needed. All patients had magnetic resonance imaging (MRI), angiography (MRA) and carotid ultrasound before surgery. Individual cognitive status was measured using four neuropsychological tests before surgery and 7 days after extubation. We compared perioperative factors for risk factors associated with postoperative stroke and postoperative cognitive decline (POCD).

RESULTS

11 patients had strokes after surgery. Operation and extracorporeal circulation times were significantly longer in patients with stroke than those without stroke. Coronary artery disease and SCP time > 150 min were independently associated with postoperative stroke. Of the 83 patients without postoperative stroke, 20 suffered POCD. POCD patients had a significantly higher rate of heterogeneous carotid plaque, and operation time was significant longer in patients with POCD than those without POCD. Independent predictors of POCD were concomitant CABG, heterogeneous carotid plaque, history of cerebrovascular disease and operation time > 450 min.

CONCLUSIONS

We found that prolonged SCP time and coronary artery disease increased the risk of postoperative stroke. Heterogeneous carotid plaque, history of cerebrovascular disease, concomitant CABG and prolonged operation time were further significant predictors of POCD.

Glymphatic System Function in Relation to Anesthesia and Sleep States

The brain is one of the most metabolically active organs in the body. The brain's high energy demand associated with wakefulness persists during rapid eye movement sleep, and even during non-rapid eye movement sleep, cerebral oxygen consumption is only reduced by 20%. The active bioenergetic state parallels metabolic waste production at a higher rate than in other organs, and the lack of lymphatic vasculature in brain parenchyma is therefore a conundrum. A common assumption has been that with a tight blood-brain barrier restricting solute and fluid movements, a lymphatic system is superfluous in the central nervous system. Cerebrospinal fluid (CSF) flow has long been thought to facilitate central nervous system tissue "detoxification" in place of lymphatics. Nonetheless, while CSF production and transport have been studied for decades, the exact processes involved in toxic waste clearance remain poorly understood. Over the past 5 years, emerging data have begun to shed new light on these processes in the form of the "glymphatic system," a novel brain-wide perivascular transit passageway dedicated to CSF transport and metabolic waste drainage from the brain. Here, we review the key anatomical components and operational drivers of the brain's glymphatic system, with a focus on its unique functional dependence on the state of arousal and anesthetic regimens. We also discuss evidence for why clinical exploration of this novel system may in the future provide valuable insight into new strategies for preventing delirium and cognitive dysfunction in perioperative and critical care settings.

Aortic cannula orientation and flow impacts embolic trajectories: computational cardiopulmonary bypass

INTRODUCTION

Emboli events are associated with the aortic cannula insertion and final position in the ascending aorta. However, the impact of subtle changes in aortic cannula movement and flow influencing embolic transport throughout the aortic arch is not well understood. The present study evaluated the aortic cannula's outflow and orientation effect on emboli entering the aortic branch arteries.

METHODS

A simplified aortic computational model was anteriorly cannulated in the distal ascending aorta with a 21-French straight aortic cannula, and two orientations were analysed by injecting gaseous and solid emboli at pump flows 2, 3 and 5 L/minute. The first aortic cannula orientation (forward flow cannula) was directed towards the lesser curvature. The second aortic cannula orientation (rear flow cannula) was tilted slightly backwards by 15°, providing flow in the retrograde direction.

RESULTS

Forward flow cannula produced a primary arch flow, whereas rear flow cannula produced a secondary arch flow resulting in four times longer emboli arch resident times than forward flow cannula. The rear flow cannula had the highest percentage of gaseous emboli entering the brachiocephalic artery of 8%, 12% and 36% (at 2, 3 and 5 L/minute, respectively). Rear flow cannula provided a positive aortic branch arterial flow at all pump flows, whereas at forward flow cannula, the brachiocephalic artery experienced retrograde flows of -1.0% (3 L/minute) and -4.0% (5 L/minute), with the left common carotid -0.23% (5 L/minute). No significant number of solid emboli entered the aortic branch arteries.

CONCLUSION

This numerical study illustrated distinct trajectory behaviours between gaseous and solid emboli where slight changes in aortic cannula orientation influenced idealised emboli direction with higher pump flows magnifying the effects.

Dexmedetomidine for the prevention of postoperative delirium in elderly patients undergoing noncardiac surgery: A meta-analysis of randomized controlled trials

BACKGROUND

Postoperative delirium (POD) among the elderly population that undergoes noncardiac surgery is significantly associated with adverse clinical outcomes. We conducted this meta-analysis to evaluate the effectiveness and safety of dexmedetomidine for the prophylaxis of POD among the elderly population after noncardiac surgery.

METHODS

We searched Embase, PubMed, and the Cochrane Library from inception date to March 2019 for randomized controlled trials (RCTs) that compared dexmedetomidine and placebo for the prevention of POD and evaluated the major cardiovascular outcomes among elderly people after noncardiac surgery. Two authors independently screened the studies and extracted data from the published articles. The main outcome was the incidence of POD. The secondary outcomes included the occurrence of bradycardia, hypotension, hypertension, tachycardia, myocardial infarction, stroke, hypoxaemia, and all-cause mortality.

RESULTS

A total of 6 RCTs with 2102 participants were included. Compared with placebo, dexmedetomidine significantly reduced the prevalence of POD (RR = 0.61, 95% CI 0.34-0.76, P = 0.001, I2 = 66%), and the risk of tachycardia (RR = 0.48, 95% CI 0.30-0.76, P = 0.002, I2 = 0%), hypertension (RR = 0.59, 95% CI 0.44-0.79, P < 0.001, I2 = 20%), stroke (RR = 0.22, 95% CI 0.06-0.76, P = 0.02, I2 = 0%), and hypoxaemia (RR = 0.50, 95% CI 0.32-0.78, P = 0.002, I2 = 0%) in elderly patients who underwent noncardiac surgery. However, dexmedetomidine accelerated the occurrence of bradycardia (RR = 1.36, 95% CI 1.11-1.67, P = 0.003, I2 = 0%). Furthermore, no significant differences were observed in the incidence of hypotension, myocardial infarction, and all-cause mortality between the dexmedetomidine and placebo groups.

CONCLUSIONS

Among elderly patients after noncardiac surgery, the prophylactic use of dexmedetomidine, compared with the use of placebo, was related to a decline in the incidence of POD.

Effect of dexmedetomidine on postoperative cognitive dysfunction and inflammation in patients after general anaesthesia: A PRISMA-compliant systematic review and meta-analysis

BACKGROUND

Neuroprotective effects of dexmedetomidine are reported in preclinical and clinical studies but evidence regarding the postoperative neurocognitive function is still unclear. This study performed a meta-analysis on outcomes of studies which examined neurocognitive performance and inflammatory factors to investigate the effects of dexmedetomidine on postoperative cognitive dysfunction (POCD) and inflammation in patients after general anaesthesia.

METHODS

Literatures were searched in several electronic databases and studies were selected by following precise inclusion criteria. We searched PubMed, EMBASE, the Cochrane Library, China Academic Journals full-text database (CNKI), and Google Scholar to find randomized controlled trials (RCTs) of the influence of dexmedetomidine on POCD and inflammation in patients who had undergone general anaesthesia. Two researchers independently screened the literature, extracted data, and evaluated quality of methodology against inclusion and exclusion criteria. Meta-analyses of pooled ORs of POCD incidences and mean differences in neurocognitive assessment scores and inflammation levels were carried out and subgroup analyses were performed. Stata 12.0 was used to conduct our meta-analysis.

RESULTS

Twenty-six RCTs were included. Compared with controls, perioperative dexmedetomidine treatment significantly reduced the incidence of POCD (pooled ORs = 0.59, 95% confidence interval (CI) 0.45-2.95) and improved Mini-Mental State Examination (MMSE) score (standardized mean difference (SMD) = 1.74, 95% CI 0.43-3.05) on the first postoperative day. Furthermore, perioperative dexmedetomidine treatment significantly decreased IL-6 (SMD = -1.31, 95% CI -1.87-0.75, P < .001) and TNF-α (SMD = -2.14, 95% CI -3.14-1.14, P < .001) compared to saline/comparators treatment. In the stratified analysis by surgical type, age, type of control, and study region, the differences were also significant between dexmedetomidine- and saline-treated patients.

CONCLUSION

Perioperative dexmedetomidine treatment is associated with significantly reduced incidence of POCD and inflammation and better neurocognitive function postoperatively in comparison with both saline controls and comparator anaesthetics.

Postoperative cognitive dysfunction is rare after fast-track hip- and knee arthroplasty - But potentially related to opioid use

STUDY OBJECTIVE

Postoperative cognitive dysfunction (POCD) remains a frequent postoperative complication in non-fast-track surgeries, with negative implications for return to daily activities and work. In fast-track total hip and -knee arthroplasty (THA/TKA) an 8-9% incidence of POCD after 3 months has been reported, but without details on specific perioperative risk factors. Thus, we re-investigated the incidence and role of suggested factors for POCD in a well-controlled patient cohort, to guide future preventive interventions.

DESIGN

A subanalysis of a prospective study.

SETTING

Hospital ward, patients own home.

PATIENTS

One-hundred-and-four patients undergoing elective THA/TKA.

INTERVENTIONS

A full contextual and validated cognitive test battery pre- and 2-3 weeks postoperatively by interview by research nurse.

MEASUREMENTS

Results from the cognitive test battery were corrected for learning effect by normative data from an age-matched unoperated control group. Potential perioperative risk factors (age, procedure, gender, inflammation, blood-percentage, opioids etc.) associated with POCD was investigated by univariate and multivariate logistic analysis, with a 5% significance level.

MAIN RESULTS

Four patients (3.9%) developed POCD. POCD-positive patients consumed higher dose of opioids in the acute postoperative period (postoperative days 0-3: median 214 mg), vs. POCD-negative patients (postoperative days 0-3: median 98 mg, p = 0.008), and during the 2-3-week study period (POCD-positive vs. POCD-negative patients, median 739 mg vs. 208 mg, respectively). Other pre and postoperative factors were non-significant but associated with the development of POCD.

CONCLUSION

POCD is rare in fast-track THA/TKA patients and may be related to postoperative opioid consumption, supporting the ongoing focus on opioid-sparing analgesia.

[Characteristics of postoperative cerebral dysfunction depending on the type and position of the implanted prosthetic heart valve]

AIM

To study the prevalence and structure of postoperative cerebral dysfunction depending on the type and position of the implanted prosthetic heart valve in patients who underwent surgery for the acquired heart valve disease.

MATERIAL AND METHODS

The study included 115 patients (70 men and 45 women; 64 [56; 72] years old), who underwent elective replacement or repair surgery for the acquired heart valve disease.

RESULTS AND CONCLUSION

The postoperative cerebral dysfunction was diagnosed in 40.9% patients, including replacement in the aortic position (45.5%), in the mitral position (55%), in several positions (20%). Replacement surgery was accompanied by three clinical types of postoperative cerebral dysfunction and repair surgery - by deferred cognitive impairment only. Postoperative cerebral dysfunction after the replacement in the mitral position was more common (odds ratio 4.47, 95% confidence interval 1.21-18.35, p=0.041), including its acute clinical types - perioperative stroke and symptomatic delirium of the early postoperative period (p=0.029), compared to that after the repair heart valve surgery. After the replacement in the aortic position, acute clinical types of postoperative cerebral dysfunction were more common (p=0.036). After the replacement with biological prosthesis, symptomatic delirium of the early postoperative period was more common (p=0.047). The occurrence of the deferred cognitive impairment didn't depend on the type and position of the implanted prosthetic heart valve.