New insights into the pathophysiology of postoperative cognitive dysfunction

Dexmedetomidine-mediated improvement of perioperative neurocognitive disorders by miR-184-3p-mediated NLRP3

BACKGROUND

Perioperative neurocognitive disorders (PND) is a neurological complication in the perioperative period, which may lead to severe poor prognosis. Dexmedetomidine (Dex) is a commonly used sedative in the perioperative period. However, the effect of intraoperative anesthetic Dex on PND remains complicated and confusing.

METHODS

PND model was established using aged male mice, treated with Dex, and subjected to behavioral tests. The effect of Dex on pyroptosis was assessed by western blot, enzyme-linked immunosorbent assay and immunofluorescence. In addition, the miRNA expression profile of PND mice was identified by small RNA sequencing and performed PCR to detect miRNAs. Finally, the effect of miRNA on mice neuron pyroptosis was verified in vitro.

RESULTS

We found postoperative cognitive was declined in PND mice compared with control group, while preoperative injection of Dex improved short-term working memory and anxious exploration behavior, alleviated the cognitive impairment. Intriguingly, Dex ameliorated hippocampal inflammation and neuron pyroptosis in PND mice as evidenced by the reduced GSDMD, NLRP3, IL-1β and IL-18. The miRNA expression profile of PND mice hippocampus was disordered, including 5 miRNAs up-regulated and 17 miRNAs down-regulated, compared to the sham group. Dysregulated miRNAs were mainly enriched in biological functions related to neuronal development and signaling pathways related to pyroptosis. MiR-184-3p was the key miRNA, overexpression of miR-184-3p blocked the inhibitory effect of Dex on neuron pyroptosis, which was manifested as increased expression of GSDMD and NLRP3, increased inflammatory factors IL-1β and IL-18.

CONCLUSIONS

This study revealed that miR-184-3p may mediate NLRP3 to prevent the alleviating effect of Dex on PND, which provides a new potential way to improve the therapeutic intervention of PND.

Ginsenoside Rg1 protects the blood-brain barrier and myelin sheath to prevent postoperative cognitive dysfunction in aged mice

In this study, the postoperative cognitive dysfunction (POCD) mouse model was established to observe the changes in inflammation, blood-brain barrier permeability, and myelin sheath, and we explore the effect of ginsenoside Rg1 pretreatment on improving POCD syndrome. The POCD model of 15- to 18-month-old mice was carried out with internal fixation of tibial fractures under isoflurane anesthesia. Pretreatment was performed by continuous intraperitoneal injection of ginsenoside Rg1(40 mg/kg/day) for 14 days before surgery. The cognitive function was detected by the Morris water maze. The contents of interleukin-1β and tumor necrosis factor-α in the hippocampus, cortex, and serum were detected by ELISA. The permeability of blood-brain barrier was observed by Evans blue. The mRNA levels and protein expression levels of 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase), myelin basic protein (MBP), beta-catenin, and cyclin D1 in the hippocampus were analyzed by quantitative PCR and western blotting. The protein expression levels of ZO-1 and Wnt1 in the hippocampus were analyzed by western blotting. Finally, the localizations of CNPase and MBP in the hippocampus were detected by immunofluorescence. Ginsenoside Rg1 can prevent POCD, peripheral and central inflammation, and blood-brain barrier leakage, and reverse the downregulation of ZO-1, CNPase, MBP, and Wnt pathway-related molecules in aged mice. Preclinical studies suggest that ginsenoside Rg1 improves postoperative cognitive function in aged mice by protecting the blood-brain barrier and myelin sheath, and its specific mechanism may be related to the Wnt/β-catenin pathway.

Does Melatonin Improve Sleep Following Primary Total Knee Arthroplasty? A Randomized, Double-Blind, Placebo-Controlled Trial

BACKGROUND

Sleep impairment following total knee arthroplasty (TKA) is common and may decrease patient satisfaction and recovery. Standardized postoperative recommendations for sleep disturbances have not been established. We aimed to assess whether melatonin use could promote healthy sleep and reduce sleep disturbance in the acute period following TKA.

METHODS

Patients undergoing primary, elective TKA between July 19, 2021 and January 4, 2024 were prospectively enrolled and randomized to receive either 5 mg of melatonin nightly or placebo for 14 days postoperatively. Participants recorded their nightly pain on the visual analog scale, the number of hours slept, and the number of night-time awakenings in a sleep diary starting the night of surgery (postoperative day [POD] 0). Sleep disturbance was assessed preoperatively and on POD 14 using the patient-reported outcome measurement information system sleep disturbance form. Epworth Sleepiness Scores were collected on POD 14 to assess sleep quality.

RESULTS

Of the 138 patients enrolled, 128 patients successfully completed the study protocol, with 64 patients in each group. Melatonin patients trended toward more hours of sleep on POD 2 (placebo: 5.0 ± 2.4, melatonin: 5.8 ± 2.0, P = .084), POD 3 (placebo: 5.6 ± 2.2, melatonin: 6.3 ± 2.0, P = .075), and averaged over POD 1 to 3 (placebo: 4.9 ± 2.0, melatonin: 5.6 ± 1.8, P = .073), although no differences were observed on POD 4 or after. Fewer night-time awakenings in the melatonin group were observed on POD 1 (placebo: 4.4 ± 3.9, melatonin: 3.6 ± 2.4, P = .197), although this was not statistically significant. Preoperative and postoperative Patient-Reported Outcomes Measurement Information System Sleep Disturbance score increases were comparable for both groups (placebo: 4.0 ± 8.4, melatonin: 4.6 ± 8.2, P = .894). The melatonin (65.4%) and placebo (65%) groups demonstrated similar rates of increased sleep disturbance.

CONCLUSIONS

Melatonin may promote longer sleep in the immediate postoperative period after TKA, although these benefits wane after POD 3. Disturbances in sleep should be expected for most patients, although melatonin may have an attenuating effect. Melatonin is safe and can be considered for TKA patients experiencing early sleep disturbances postoperatively.

C8-ceramide modulates microglia BDNF expression to alleviate postoperative cognition dysfunction via PKCδ/NF-κB signaling pathway

Postoperative cognitive dysfunction (POCD) is a kind of serious postoperative complication in surgery with general anesthesia and it may affect patients' normal lives. Activated microglia are thought to be one of the key factors in the regulation of POCD process. Once activated, resident microglia change their phenotype and secrete kinds of cytokines to regulate inflammatory response in tissues. Among these secretory factors, brain-derived neurotrophic factor (BDNF) is considered to be able to inhibit inflammation response and protect nervous system. Therefore, the enhancement of BDNF expression derived from resident microglia is suggested to be potential treatment for POCD. In our study, we focused on the role of C8-ceramide (a kind of interventional drug) and assessed its regulatory effect on improving the expression of BDNF secreted from microglia to treat POCD. According to the results of our study, we observed that C8-ceramide stimulated primary microglia to up-regulate the expression of BDNF mRNA after being treated with lipopolysaccharide (LPS) in vitro. We proved that C8-ceramide had ability to effectively improve POCD of mice after being accepted carotid artery exposure and their abnormal behavior recovered better than that of mice from the surgery group. Furthermore, we also demonstrated that C8-ceramide enhanced the cognitive function of mice via the PKCδ/NF-κB signaling pathway. In general, our study has confirmed a potential molecular mechanism that led to the occurrence of POCD caused by surgery and provided a new clinical strategy to treat POCD.

Postoperative cognitive dysfunction: a concept analysis

BACKGROUND

Post-operative cognitive dysfunction (POCD) is a concern for clinicians that often presents post-surgery where generalized anesthesia has been used. Its prevalence ranges from 36.6% in young adults to 42.4% in older individuals. Conceptual clarity for POCD is lacking in the currently body literature. Our two-fold purpose of this concept analysis was to (1) critically appraise the various definitions, while also providing the best definition, of POCD and (2) narratively synthesize the attributes, surrogate or related terms, antecedents (risk factors), and consequences of the concept.

METHOD

The reporting of our review was guided by the PRISMA statement and the 6-step evolutionary approach to concept analysis developed by Rodgers. Three databases, including Medline, CINAHL, and Web of Science, were searched to retrieve relevant literature on the concept of POCD. Two independent reviewers conducted abstract and full-text screening, data extraction, and appraisal. The review process yielded a final set of 86 eligible articles.

RESULT

POCD was defined with varying severities ranging from subtle-to-extensive cognitive changes (1) affecting single or multiple cognitive domains that manifest following major surgery (2), is transient and reversible, and (3) may last for several weeks to years. The consequences of POCD may include impaired quality of life, resulting from withdrawal from the labor force, increased patients' dependencies, cognitive decline, an elevated risk of dementia, rising healthcare costs, and eventual mortality.

CONCLUSION

This review resulted in a refined definition and comprehensive analysis of POCD that can be useful to both researchers and clinicians. Future research is needed to refine the operational definitions of POCD so that they better represent the defining attributes of the concept.

J147 affects cognition and anxiety after surgery in Zucker rats

Vulnerable patients are at risk for neuroinflammation-mediated post-operative complications, including depression (POD) and cognitive dysfunction (POCD). Zucker rats, expressing multiple risk factors for post-operative complications in humans, may provide a clinically relevant model to study pathophysiology and explore potential interventions. J147, a newly developed anti-dementia drug, was shown to prevent POCD in young healthy rats, and improved early post-surgical recovery in Zucker rats. Aim of the present study was to investigate POCD and the therapeutic potential of J147 in male Zucker rats. Risk factors in the Zucker rat strain were evaluated by comparison with lean littermates. Zucker rats were subjected to major abdominal surgery. Acute J147 treatment was provided by a single iv injection (10 mg/kg) at the start of surgery, while chronic J147 treatment was provided in the food (aimed at 30 mg/kg/day), starting one week before surgery and up to end of protocol. Effects on behavior were assessed, and plasma, urine and brain tissue were collected and processed for immunohistochemistry and molecular analyses. Indeed, Zucker rats displayed increased risk factors for POCD, including obesity, high plasma triglycerides, low grade systemic inflammation, impaired spatial learning and decreased neurogenesis. Surgery in Zucker rats reduced exploration and increased anxiety in the Open Field test, impaired short-term spatial memory, induced a shift in circadian rhythm and increased plasma neutrophil gelatinase-associated lipocalin (NGAL), microglia activity in the CA1 and blood brain barrier leakage. Chronic, but not acute J147 treatment reduced anxiety in the Open Field test and protected against the spatial memory decline. Moreover, chronic J147 increased glucose sensitivity. Acute J147 treatment improved long-term spatial memory and reversed the circadian rhythm shift. No anti-inflammatory effects were seen for J147. Although Zucker rats displayed risk factors, surgery did not induce extensive POCD. However, increased anxiety may indicate POD. Treatment with J147 showed positive effects on behavioral and metabolic parameters, but did not affect (neuro)inflammation. The mixed effect of acute and chronic treatment may suggest a combination for optimal treatment.

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.

Physical activity compensates for isoflurane-induced selective impairment of neuronal progenitor cell proliferation in the young adult hippocampus

General anesthesia is considered a risk factor for postoperative cognitive dysfunction. However, it is unclear what the neuronal and cognitive consequences of general anesthesia are and whether they can be treated. One possible pathomechanism is hippocampal neurogenesis. We investigated how the anesthetic isoflurane affects adult hippocampal neurogenesis and associated cognitive functions and whether the neurogenic stimulus of physical activity reverses isoflurane-induced changes. We exposed young adult mice to isoflurane (ISO) - half had access to a running wheel (ISO-RW). Both groups were compared with a control condition (CTR; CTR-RW). Cell proliferation and survival in the dentate gyrus of the hippocampus were quantified histologically 48 h and 3 weeks after anesthesia by bromodeoxyuridine incorporation. Cell phenotype was determined by expression of neuronal markers, and the extent of continuous endogenous neuronal proliferation was estimated from the number of doublecortin-positive cells. The Morris water maze was used to test hippocampus-dependent functions. We found that isoflurane decreased proliferation of neuronal progenitor cells, whereas survival of mature neurons remained intact. Consistent with intact neuronal survival, spatial memory associated with neurogenesis also proved intact in the Morris water maze despite isoflurane exposure. Physical activity attenuated the observed neuronal changes by preventing the decrease in newborn neuronal progenitor cells and the decline in continuous endogenous neuronal proliferation in isoflurane-treated animals. In conclusion, isoflurane selectively impairs neuronal proliferation but not survival or neurogenesis-linked cognition in adult mice. The observed adverse effects can be attenuated by physical activity, a cost-effective means of preventing the neurogenic consequences of general anesthesia.

The elderly in the post-anesthesia care unit

It is increasingly conceivable that elderly patients will be treated in perioperative settings as the world's population shifts toward an older age distribution. They are more prone to a variety of unfavorable outcomes as a consequence of the physiological changes that accompany aging and the coexistence of multiple medical conditions. Postoperative complications in elderly patients are linked to a large increase in morbidity and mortality and the burden placed on the healthcare system. Our goal is to determine how elderly patients' recovery after anesthesia differs from that of younger patients. In addition, we will discuss the main postoperative complications experienced by elderly patients and the measures that are utilized to limit the risk of these complications developing.

Plasma lipidomics reveals potential lipid markers for the prediction of delayed neurocognitive recovery after cardiac surgery with cardiopulmonary bypass

BACKGROUND

Delayed neurocognitive recovery (DNR) is a cognitive change that affects patients after anesthesia and surgery, with a high incidence, severely impairing their quality of life. We identified relevant metabolic pathways to determine predictive lipid markers and understand the pathogenesis of DNR.

METHODS

A non-targeted lipidomic strategy using Waters Acquity I Class UPLC-Xevo G2-S QTOF UPLC-MS was employed to identify different lipids in the 24 h postoperative plasma of patients whose cognitive function was assessed 7-14 days after surgery. Principal component analysis, orthogonal partial least squares discriminant analysis, and receiver operating characteristic (ROC) curves were used to identify potential biomarkers for predicting DNR. Metabolic pathway analysis was performed using the online platform MetaboAnalyst 5.0.

RESULTS

Pre-operative hemoglobin was identified as an independent risk factor for DNR. The individual areas under the ROC curves (AUC) of the 5 representative lipids were all > 0.6, and the AUC of the combined predictor was 0.912. Glycerophospholipid metabolic pathway was dysregulated in patients with subsequent DNR.

CONCLUSION

This study identified a series of potential predictive biomarkers for DNR. These data suggested that glycerophospholipid metabolism may be the mechanism underlying the occurrence and progression of DNR.

Usability and feasibility of a digital cognitive screening tool measuring older adults' early postoperative neurocognitive recovery: a protocol for a pilot study

INTRODUCTION

Delayed neurocognitive recovery, also identified as early postoperative cognitive decline (POCD), is a common complication after surgery, with advanced age being the most important risk factor. As the geriatric population is increasing worldwide, and number of older adults undergoing surgery continues to rise, so will the incidence of POCD. Only a small proportion use digital cognitive tests for measuring postoperative neurocognitive performance compared with analogue tests. This study aims to evaluate a digital cognitive screening tool, Mindmore Postoperative version (Mindmore-P), in a perioperative setting to determine its feasibility and usability, and to compare preoperative cognition with early postoperative neurocognitive performance. Further, to determine associations between neurocognitive performance and perioperative factors as well as to explore patients' experiences of early neurocognitive recovery.

METHODS AND ANALYSIS

We will include 50 patients (aged ≥60 years) undergoing elective abdominal surgery under general anaesthesia. Cognitive functions will be measured with Mindmore-P preoperatively and on postoperative day (POD) 1 or 2 as well as 2-3 weeks after surgery. Preoperatively, frailty, (Clinical Frailty Scale), depression (Geriatric Depression Scale-15), functional status (12-item WHO Disability Assessment Schedule 2.0) and pre-recovery status (Swedish web version Quality of Recovery Scale, SwQoR) will be measured. Delirium will be assessed by Nu-DESC (Nursing Delirium Screening Scale) twice a day, with start on POD 1 and until the patient is discharged from the hospital. Outcomes at 2-3 weeks postoperatively are postoperative recovery (SwQoR), depression, functional status and usability (System Usability Scale) of Mindmore-P. Postoperative recovery will also be measured POD 1 or 2. We will also explore feasibility and experience of early postoperative neurocognitive recovery with interviews approximately 1 month after surgery.

ETHICS AND DISSEMINATION

This study is approved by the Swedish Ethical Review Authority (REC Reference: 2022-03593-01) and will follow the principles outlined in the 1964 Helsinki Declaration and its later amendments. Results from this study will be disseminated in peer-reviewed journals, scientific conferences and in social media.

TRIAL REGISTRATION NUMBER

NCT05564195.

Risk factors for postoperative cognitive dysfunction in elderly patients undergoing surgery for oral malignancies

We aimed to analyse postoperative cognitive dysfunction (POCD) incidence and risk factors in elderly adults who underwent surgery for oral malignancies. A total of 112 elderly patients (aged ≥ 55 years) were selected for expanded resection of oral malignancy and cervical lymphatic dissection at our institution from December 2020 to December 2021. Participants were cognitively evaluated using the neuropsychological test scale 1 day before and 7 days after surgery to determine whether they had developed POCD. Based on whether POCD occurred 7 days after surgery, patients were classified into the POCD and non-POCD groups. Logistic regression was applied to perioperative factors to analyse the risk factors for POCD onset. Seven days after surgery for oral malignancy, there were 37 (33.1%) POCD morbidities. Multiple factor logistic regression analysis revealed that venerable age (odds ratio [OR] = 1.269, 95% confidence interval [CI] 1.056-1.525, P < 0.05), low education levels (OR = 0.792, 95% CI 0.644-0.974, P < 0.05), hypertension (OR = 4.153, 95% CI 1.335-12.732, P < 0.05), dyssomnia (OR = 1.272, 95% CI 1.001-1.617, P < 0.05), prolonged anaesthesia (OR = 1.009, 95% CI 1.001-1.018, P < 0.05), and intraoperative hypotension (OR = 5.512, 95% CI 1.240-24.506, P < 0.05) increased the POCD risk in elderly patients who underwent surgery for oral malignancies. Venerable age, low knowledge reserve, hypertension, dyssomnia, prolonged anaesthesia, and intraoperative hypotension are independent risk factors for POCD in elderly patients with oral malignancies.

Postoperative Delirium and Cognitive Dysfunction after General and Regional Anesthesia: A Systematic Review and Meta-Analysis

Background: Perioperative disorders of neurocognitive function are a set of heterogeneous conditions, which include transient post-operative delirium (POD) and more prolonged post-operative cognitive dysfunction (POCD). Since the number of annually performed surgical procedures is growing, we should identify which type of anesthesia is safer for preserving neurocognitive function. The purpose of this study was to compare the effect of general anesthesia (GA) and regional anesthesia (RA) in patients undergoing surgical procedures under general anesthesia and regional anesthesia. Material and methods: We searched for randomized controlled studies, which studied post-operative cognitive outcomes after general and regional anesthesia in the adult patient population. Results: Thirteen articles with 3633 patients: the RA group consisted of 1823 patients, and the GA group of 1810 patients, who were selected for meta-analysis. The overall effect of the model shows no difference between these two groups in terms of risk for post-operative delirium. The result is insensitive to the exclusion of any study. There was no difference between RA and GA in terms of post-operative cognitive dysfunction. Conclusions: There was no statistically significant difference between GA and RA in the incidence of POD. There was no statistically significant difference in the incidence of POCD per-protocol analysis, psychomotor/attention tests (preoperative/baseline, post-operative), memory tests (postoperatively, follow up), mini-mental state examination score 24 h postoperatively, post-operative reaction time three months postoperatively, controlled oral word association test, and digit copying test. There were no differences in the incidence of POCD in general and regional anesthesia at one week postoperatively, three months postoperatively, or total events (one week or three months). The incidence of post-operative mortality also did not differ between two groups.

Whole body vibration, an alternative for exercise to improve recovery from surgery?

Although exercise is usually associated with beneficial effects on physical and mental health, patients recovering from surgery may be hampered to perform active exercise. Whole body vibration (WBV) is suggested a passive alternative for physical training. Aim of the present study was to explore the therapeutic potential of WBV compared to physical exercise during early post-surgery recovery.

Male three months old Wistar rats underwent major abdominal surgery. Starting the day after surgery, rats were subjected to either daily WBV or exercise (treadmill running) for 15 consecutive days. Control rats underwent pseudo treatment. During the first week after surgery, effects of interventions were obtained from continuous recording of hemodynamic parameters, body temperature and activity (via an implanted transducer). Behavioral tests were performed during the second post-surgical week to evaluate anxiety-like behavior, short and long-term memory functions, cognitive flexibility and motor performance. Animals were sacrificed 15 days after surgery and brain tissue was collected for analysis of hippocampal neuroinflammation and neurogenesis.

Surgery significantly impacted all parameters measured during the first post-surgery week, irrespective of the type of surgery. Effect on cognitive performance was limited to cognitive flexibility; both WBV and exercise prevented the surgery-induced decline. Exercise, but not WBV increased anxiety-like behavior and grip strength. WBV as well as exercise prevented the surgery-induced declined neurogenesis, but surgery-associated hippocampal neuroinflammation was not affected.

Our results indicated that active exercise and WBV share similar therapeutic potentials in the prevention of surgery induced decline in cognitive flexibility and hippocampal neurogenesis. In contrast to exercise, WBV did not increase anxiety-like behavior. Since neither intervention affected hippocampal neuroinflammation, other mechanisms and/or brain areas may be involved in the behavioral effects. Taken together, we conclude that WBV may provide a relevant alternative to active exercise during the early stage of post-operative recovery.

•

Both whole body vibration (WBV) and running exercise restored the reduced cognitive flexibility caused by surgery.

•

WBV as well as active exercise prevented surgery-induced declined neurogenesis.

•

Active exercise, but not WBV, induced anxiety-like behavior after surgery.

•

Neither WBV nor active exercise affected surgery-induced neuroinflammation.

•

Neither WBV nor active exercise influenced hemodynamic recovery from surgery.

Clinically Optimal Neuropsychological Tests for Postoperative Cognitive Dysfunction in Heart Valve Surgeries

BACKGROUND

Postoperative cognitive dysfunction (POCD) is widely recognized and reported, but the lack of a uniform definition makes it difficult to evaluate its clinical impact. The aim of this study is to establish the optimal neuropsychological tests and definition of POCD relevant to clinical outcomes in heart valve surgeries.

METHODS AND RESULTS

Between June 2015 and December 2019, 315 patients undergoing elective heart valve surgeries (age ≥65 years) were enrolled. The Mini-Mental Status Examination, Montreal Cognitive Assessment (MoCA), and the Trail Making Test A and B were performed to evaluate cognitive function. Clinical endpoints were defined as readmission and death. The postoperative readmission and death rate were 17% and 3% (54/315 and 8/315; follow-up 266-1,889 days). By multivariable Cox hazard analysis, Short Physical Performance Battery (adjusted hazard ratio [HR]: 0.84, 95% confidence interval [CI]: 0.49-0.98, P=0.001), MoCA change rate (adjusted HR: 0.64, 95% CI: 0.01-1.22, P=0.024), and intensive care unit stay (adjusted HR: 0.55%, 95% CI: 0.99-1.12, P=0.054) were detected as independent risk factors for combined events. The cutoff value was -12% in the change rate of MoCA.

CONCLUSIONS

MoCA was the only neuropsychological test that predicted the clinical impact on complex events and has the potential to define POCD.

Groin Puncture to Recanalization Time May Be a Strong Predictor of mTICI 2c/3 over mTICI 2b in Patients with Large Vessel Occlusions Successfully Recanalized with Mechanical Thrombectomy

Mechanical thrombectomy (MT) is an important therapeutic option in the management of acute ischemic stroke (AIS) caused by large vessel occlusions (LVO). While achieving a modified thrombolysis in cerebral infarction (mTICI), grades of 2b, 2c, and 3 are all considered successful recanalization; recent literature suggests that mTICI grades of 2c/3 are associated with superior outcomes than 2b. The aim of this preliminary study is to determine whether any baseline or procedural parameters can predict whether successfully recanalized patients achieve an mTICI grade of 2c/3 over 2b. Consecutive patients from 9/2019 to 10/2021 who were successfully recanalized following MT for confirmed LVO were included in the study. Baseline and procedural data were collected through manual chart review and analyzed to ascertain whether any variables of interest could predict mTICI 2c/3. A total of 47 patients were included in the preliminary study cohort, with 35 (74.5%) achieving an mTICI score of 2c/3 and 12 (25.5%) achieving an mTICI score of 2b. We found that a lower groin puncture to recanalization time was a strong, independent predictor of TICI 2c/3 (p = 0.015). These findings emphasize the importance of minimizing procedure time in achieving superior reperfusion but must be corroborated in larger scale studies.

Is the analogue cognitive test from the ISPOCD equivalent to the digital cognitive test Mindmore? A protocol for a randomised cross-over study including qualitative interviews with self-reported healthy seniors

INTRODUCTION

Postoperative cognitive decline affects cognitive domains such as executive functions, memory, concentration and information processing. The analogue neuropsychological test developed by the International Study Group of Postoperative Cognitive Dysfunction (ISPOCD) is a well-established test for assessing cognitive performance. However, analogue tests are time-consuming, rarely cost-effective and can be at risk of administration bias. Digital solutions are comparable to analogue ones, have higher degrees of compliance and enable more standardised execution than analogue tests. Currently, there is a lack of recommendations for clinical evaluation of the patient's cognition in the perioperative setting, standard care usually means no cognitive assessments prior or after the surgery. There is a need to find an equivalent neuropsychological test to the ISPOCD to make it accessible and easier to implement in a clinical context for perioperative patients. This study aims to examine how healthy seniors perform on two neuropsychological tests, analogue versus digital and measure equivalency between tests with correlation analysis.

METHODS AND ANALYSIS

This study will use a randomised cross-over design, including qualitative interviews regarding test experiences. Healthy participants ≥60 years of age will be eligible to participate in the study. Cognitive function will be measured by using the ISPOCD test and the Mindmore digital test. The participants will self-report depressive symptoms with the Geriatric Depression Scale-15, user experience of the digital test using a modified version of the System Usability Scale and answer questionnaires targeting their experiences after the tests. Furthermore, according to the Swedish Quality of Recovery Scale, self-reported concentration difficulties will also be measured.

ETHICS AND DISSEMINATION

The study has been approved by the Swedish Ethical Review Authority (Dnr 2021-05486-01) and will follow the principles outlined in the 1964 Helsinki Declaration and its later amendments. Results from this study will be disseminated in peer-reviewed journals, at scientific conferences, and in social media.

TRIAL REGISTRATION NUMBER

2021-01095; ClinicalTrials.gov.

Neuroinflammation as the Underlying Mechanism of Postoperative Cognitive Dysfunction and Therapeutic Strategies

Postoperative cognitive dysfunction (POCD) is a common neurological complication following surgery and general anesthesia, especially in elderly patients. Severe cases delay patient discharge, affect the patient’s quality of life after surgery, and are heavy burdens to society. In addition, as the population ages, surgery is increasingly used for older patients and those with higher prevalences of complications. This trend presents a huge challenge to the current healthcare system. Although studies on POCD are ongoing, the underlying pathogenesis is still unclear due to conflicting results and lack of evidence. According to existing studies, the occurrence and development of POCD are related to multiple factors. Among them, the pathogenesis of neuroinflammation in POCD has become a focus of research in recent years, and many clinical and preclinical studies have confirmed the correlation between neuroinflammation and POCD. In this article, we reviewed how central nervous system inflammation occurred, and how it could lead to POCD with changes in peripheral circulation and the pathological pathways between peripheral circulation and the central nervous system (CNS). Furthermore, we proposed some potential therapeutic targets, diagnosis and treatment strategies at the cellular and molecular levels, and clinical applications. The goal of this article was to provide a better perspective for understanding the occurrence of POCD, its development, and preventive strategies to help manage these vulnerable geriatric patients.

Suppression of Neuroinflammation Attenuates Persistent Cognitive and Neurogenic Deficits in a Rat Model of Cardiopulmonary Bypass

Post-operative cognitive dysfunction (POCD) can be a serious surgical complication, and patients undergoing cardiac procedures are at particular risk for POCD. This study examined the effect of blocking neuroinflammation on behavioral and neurogenic deficits produced in a rat model of cardiopulmonary bypass (CPB). Minocycline, a drug with established anti-inflammatory activity, or saline was administered daily for 30 days post-CPB. Treatment with minocycline reduced the number of activated microglia/macrophages observed in the dentate gyrus of the hippocampus at 6 months post-CPB, consistent with an anti-inflammatory action in this CPB model. Behavioral testing was conducted at 6 months post-CPB utilizing a win-shift task on an 8-arm radial maze. Minocycline-treated animals performed significantly better than saline-treated animals on this task after CPB. In addition, the CPB-induced reduction in adult neurogenesis was attenuated in the minocycline-treated animals. Together, these findings indicate that suppressing neuroinflammation during the early post-surgical phase can limit long-term deficits in both behavioral and neurogenic outcomes after CPB.

Recent advances and perspectives of postoperative neurological disorders in the elderly surgical patients

Postoperative neurological disorders, including postoperative delirium (POD), postoperative cognitive dysfunction (POCD), postoperative covert ischemic stroke, and hemorrhagic stroke, are challenging clinical problems in the emerging aged surgical population. These disorders can deteriorate functional outcomes and long‐term quality of life after surgery, resulting in a substantial social and financial burden to the family and society. Understanding predisposing and precipitating factors may promote individualized preventive treatment for each disorder, as several risk factors are modifiable. Besides prevention, timely identification and treatment of etiologies and symptoms can contribute to better recovery from postoperative neurological disorders and lower risk of long‐term cognitive impairment, disability, and even death. Herein, we summarize the diagnosis, risk factors, prevention, and treatment of these postoperative complications, with emphasis on recent advances and perspectives.

Effects of inhalation and propofol anaesthesia on postoperative cognitive dysfunction in elderly noncardiac surgical patients: A systematic review and meta-analysis

BACKGROUND

Postoperative cognitive dysfunction (POCD) is a very common event in elderly noncardiac surgical patients. The effects of inhalational anaesthetics and propofol on the incidence of POCD and postoperative cognitive status at different time points after surgery are currently unclear.

METHODS

We searched the Embase, Medline, Cochrane Library, and Web of Science databases for randomized controlled trials (RCTs), in which inhalation anaesthesia and propofol anaesthesia were compared. The incidence of POCD or postoperative cognitive status was assessed in elderly patients undergoing noncardiac surgery.

RESULTS

Fifteen RCTs with 1854 patients were included in this meta-analysis. The incidence of POCD on postoperative Days 2-6 after propofol anaesthesia was markedly lower than that after inhalation anaesthesia (risk ratio (RR): 0.37, 95% confidence interval (CI): 0.15-0.88, P = .025), and Mini-Mental State Examination (MMSE) scores after propofol anaesthesia were substantially higher than those after inhalation anaesthesia (standard mean difference (SMD): 0.59, 95% CI: 0.07-1.11, P = .026). The levels of interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) were much lower after propofol anaesthesia than after inhalation anaesthesia (SMD: -2.027, 95% CI: -3.748- -0.307, P = .021; SMD: -0.68, 95% CI: -0.93- -0.43, P < .001).

CONCLUSIONS

The moderate evidence from this meta-analysis shows that, in elderly noncardiac surgical patients, propofol anaesthesia is superior to inhalation anaesthesia for attenuating of early POCD incidence, and low-level evidence shows that cognitive status is higher and systemic inflammation is less severe after propofol anaesthesia in the early days after surgery.

LIMITATIONS

The sample size was not sufficiently large for systemic inflammation, and the tools to identify POCD were not uniform in the included studies.

miRNA-124-3p targeting of LPIN1 attenuates inflammation and apoptosis in aged male rats cardiopulmonary bypass model of perioperative neurocognitive disorders

Perioperative neurocognitive disorder (PND) is recently recommended to define the cognitive decrease during the perioperative period. However, the disease's underlying mechanisms remain unclear. MicroRNAs (miRNAs) are noncoding RNAs that play a vital role in regulating neuroregeneration and neuronal apoptosis. In this study, miR-124-3p was significantly reduced in the PND rat model after a cardiopulmonary bypass (CPB) procedure. MicroRNA-124 (miR-124)-3p-overexpressed lentivirus was constructed and injected via the intracerebroventricular method before CPB. Morris Water Maze test (WMW) and the Open-Field test (OFT) were used to measure behavior changes, data shows decline of cognitive function of rats after CPB. PND rats expressed higher Aβ and p-Tau Protein by using immunohistochemistry (IHC) analyses and Enzyme-Linked Immune Sorbent Assay (ELISA). Moreover, the results of IHC, ELISA, Western Blot analysis (WB) and Terminal-deoxynucleotidyl Transferase Mediated Nick End Labeling Assay (TUNEL) showed CPB procedure induced inflammation and apoptosis in rats with PND. The data also revealed the protective function of miR-124-3p overexpression against PND in relieving inflammation, cell apoptosis, and alleviating repaired cognitive function. Moreover, miR-124-3p was predicted by directly targeting LPIN1. This study gives a novel viewpoint that miR-124-3p could improve the state of PND via modulating LPIN1, therefore providing a new strategy for preventing and treating PND in a preclinical application.

Pharmacological potential of JWH133, a cannabinoid type 2 receptor agonist in neurodegenerative, neurodevelopmental and neuropsychiatric diseases

The pharmacological activation of cannabinoid type 2 receptors (CB2R) gained attention due to its ability to mitigate neuroinflammatory events without eliciting psychotropic actions, a limiting factor for the drugs targeting cannabinoid type 1 receptors (CB1R). Therefore, ligands activating CB2R are receiving enormous importance for therapeutic targeting in numerous neurological diseases including neurodegenerative, neuropsychiatric and neurodevelopmental disorders as well as traumatic injuries and neuropathic pain where neuroinflammation is a common accompaniment. Since the characterization of CB2R, many CB2R selective synthetic ligands have been developed with high selectivity and functional activity. Among numerous ligands, JWH133 has been found one of the compounds with high selectivity for CB2R. JWH133 has been reported to exhibit numerous pharmacological activities including antioxidant, anti-inflammatory, anticancer, cardioprotective, hepatoprotective, gastroprotective, nephroprotective, and immunomodulatory. Recent studies have shown that JWH133 possesses potent neuroprotective properties in several neurological disorders, including neuropathic pain, anxiety, epilepsy, depression, alcoholism, psychosis, stroke, and neurodegeneration. Additionally, JWH133 showed to protect neurons from oxidative damage and inflammation, promote neuronal survival and neurogenesis, and serve as an immunomodulatory agent. The present review comprehensively examined neuropharmacological activities of JWH133 in neurological disorders including neurodegenerative, neurodevelopmental and neuropsychiatric using synoptic tables and elucidated pharmacological mechanisms based on reported observations. Considering the cumulative data, JWH133 appears to be a promising CB2R agonist molecule for further evaluation and it can be a prototype agent in drug discovery and development for a unique class of agents in neurotherapeutics. Further, regulatory toxicology and pharmacokinetic studies are required to determine safety and proceed for clinical evaluation.

Perioperative Sleep Disorder: A Review

Patients in the perioperative period usually present with different types and degrees of sleep disorders, which can severely affect their post-operative outcomes. Multiple risk factors may lead to the occurrence of perioperative sleep disorders, including personal factors, psychological factors, surgery factors, and environmental factors. In this review, we summarize the potential risk factors for perioperative sleep disorders during hospitalization. And it also provides an overview of perioperative outcomes and potential therapeutic prevention of perioperative sleep disorders. However, the further search is necessary to investigate the effectiveness and safety of preventions in the clinical practice and push forward the therapies.

The international ENIGMA-II substudy on postoperative cognitive disorders (ISEP)

There is a large controversy as to whether nitrous oxide (N₂O) added to the anaesthetic gas mixture is harmful or harmless for postoperative cognitive function recovery. We performed a nested study in the ENIGMA-II trial and compared postoperative neurocognitive recovery of patients randomly receiving N₂O (70%) or Air (70%) in 30% O₂ during anesthesia. We included adults having non cardiac surgery. We compared recovery scores for episodic memory, decision making/processing speed and executive functions measured with the computerised Cambridge Neuropsychological Test Automated Battery (CANTAB). Assessments were performed at baseline, seven and ninety days. At first interim analysis, following recruitment of 140 participants, the trial was suspended. We found that the mean (95%CI) changes of scores for episodic memory were in the Pocock futility boundaries. Decision making/processing speed did not differ either between groups (P > 0.182). But for executive functions at seven days, the mean number (95% CI) of problems successfully solved and the number of correct box choices made was higher in the N2O group, P = 0.029. N₂O with the limitations of an interim analysis appears to have no harmful effect on cognitive functions (memory/processing speed). It may improve the early recovery process of executive functions. This preliminary finding warrants further investigations.

Effect of phenylephrine on cerebral oxygen saturation and cardiac output in adults when used to treat intraoperative hypotension: a systematic review

OBJECTIVE

The objective of this review was to examine the effect of phenylephrine on cerebral oxygen saturation, cardiac output, and middle cerebral artery blood flow velocity when used to treat intraoperative hypotension.

INTRODUCTION

While the etiology of postoperative cognitive dysfunction in adults following surgery is likely multifactorial, intraoperative cerebral hypoperfusion is a commonly proposed mechanism. Research evidence and expert opinion are emerging that suggest phenylephrine adversely affects cerebral oxygen saturation and may also adversely affect cerebral perfusion via a reduction in cardiac output or cerebral vascular vasoconstriction. The administration of phenylephrine to treat intraoperative hypotension is common anesthesia practice, despite a lack of evidence to show it improves cerebral perfusion. Therefore, a systematic review of the effect of phenylephrine on cerebral hemodynamics has significant implications for anesthesia practice and future research.

INCLUSION CRITERIA

Studies of adults 18 years and over undergoing elective, non-neurosurgical procedures involving anesthesia were included. In these studies, participants received phenylephrine to treat intraoperative hypotension. The effect of phenylephrine on cerebral oxygen saturation, cardiac output, or middle cerebral artery blood flow velocity was measured.

METHODS

Key information sources searched included MEDLINE (Ovid), Embase, CINAHL (EBSCO), and Google Scholar. The scope of the search was limited to English-language studies published from 1999 through 2017. The recommended JBI approach to critical appraisal, study selection, data extraction, and data synthesis were used.

RESULTS

This systematic review found that phenylephrine consistently decreased cerebral oxygen saturation values despite simultaneously increasing mean arterial pressure to normal range. Results also found that ephedrine and dopamine were superior to phenylephrine in maintaining or increasing values. Phenylephrine was found to be similar to vasopressin in the extent to which both decreased cerebral oxygen saturation values. Results also showed that phenylephrine resulted in statistically significant declines in cardiac output, or failed to improve abnormally low preintervention values. The effect of phenylephrine on middle cerebral artery blood flow velocity was only measured in one study and showed that phenylephrine increased flow velocity by about 20%. Statistical pooling of the study results was not possible due to the gross variation in how the intervention was administered and how effect was measured.

CONCLUSIONS

This review found that phenylephrine administration resulted in declines in cerebral oxygen saturation and cardiac output. However, the research studies were ineffective in informing phenylephrine's mechanism of action or its impact on postoperative cognitive function.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO (CRD42018100740).

Impairment of Cognitive Function in Different Domains Early After Lung Transplantation

In this prospective observational pilot study patients with the diagnosis of end-stage lung disease and listed for lung transplantation underwent a cognitive function test battery before and after lung transplantation to investigate postoperative cognitive function in three domains (visual and verbal memory, executive functioning, concentration/speed of processing). Additionally we investigated intraoperative risk factors for postoperative cognitive dysfunction. In total, 24 patients were included in this pilot study. The incidence of postoperative cognitive dysfunction was 58.3%. In the cognitive dysfunction group, the domains executive functioning and concentration/attention were significantly impaired whereas memory was not affected. Patients with cognitive impairment had a significantly longer ICU stay. The strongest independent risk factor for the development of cognitive dysfunction was operation time. No influence of cerebral oxygen desaturations on cognitive dysfunction was found. This might have important implications for early psychological rehabilitation strategies in this high-risk patient collective.

Biomarkers of Cerebral Injury for Prediction of Postoperative Cognitive Dysfunction in Patients Undergoing Cardiac Surgery

OBJECTIVES

To assess the ability of the biomarkers neuron-specific enolase (NSE), tau, neurofilament light chain (NFL), and glial fibrillary acidic protein (GFAP) to predict postoperative cognitive dysfunction (POCD) at discharge in patients who underwent cardiac surgery.

DESIGN

Post hoc analyses (with tests being prespecified before data analyses) from a randomized clinical trial.

SETTING

Single-center study from a primary heart center in Denmark.

PARTICIPANTS

Adult patients undergoing elective or subacute on-pump coronary artery bypass grafting and/or aortic valve replacement.

INTERVENTIONS

Blood was collected before induction of anesthesia, after 24 hours, after 48 hours, and at discharge from the surgical ward. The International Study of Postoperative Cognitive Dysfunction test battery was applied to diagnose POCD at discharge and after three months. Linear mixed models of covariance were used to assess whether repeated measurements of biomarker levels were associated with POCD. Receiver operating characteristic (ROC) curves were applied to assess the predictive value of each biomarker measurement for POCD.

MEASUREMENTS AND MAIN RESULTS

A total of 168 patients had biomarkers measured at baseline, and 47 (28%) fulfilled the POCD criteria at discharge. Patients with POCD at discharge had significantly higher levels of tau (p = 0.02) and GFAP (p = 0.01) from baseline to discharge. The biomarker measurements achieving the highest area under the ROC curve for prediction of POCD at discharge were NFL measured at discharge (AUC, 0.64; 95% confidence interval [CI], 0.54-0.73), GFAP measured 48 hours after induction (AUC, 0.64; 95% CI, 0.55-0.73), and GFAP measured at discharge (AUC, 0.64; 95% CI, 0.54-0.74), corresponding to a moderate predictive ability.

CONCLUSIONS

Postoperative serum levels of tau and GFAP were elevated significantly in patients with POCD who underwent cardiac surgery at discharge; however, the biomarkers achieved only modest predictive abilities for POCD at discharge. Postoperative levels of NSE were not associated with POCD at discharge.

The role of intraoperative hypotension on the development of postoperative cognitive dysfunction: a systematic review

STUDY OBJECTIVE

To clarify whether intraoperative hypotension contributes to the development of postoperative cognitive dysfunction.

DESIGN

A systematic review of prospective studies reporting on intraoperative hypotension and postoperative cognitive dysfunction in elective, non-cognitive impaired, adult surgical patients. PubMed, EMBASE and the Cochrane Library were searched up to the 1st of January 2021.

SETTING

Studies had to use a clear definition of hypotension, although differing definitions were accepted. Neurocognitive tests to determine postoperative cognitive dysfunction had to be done pre- and postoperatively, with a minimum follow-up of seven days postoperatively.

MEASUREMENTS

Risk of bias was assessed using the Cochrane Risk of Bias Tool 2.0 for randomized controlled trials and the Newcastle-Ottawa Scale for cohort studies.

MAIN RESULTS

Out of 941 studies screened, five randomized controlled trials and four cohort studies were included for qualitative analysis. Extensive methodological differences between studies were present hindering proper quantitive analysis. No studies reported statistically significant differences in incidence of postoperative cognitive dysfunction in hypo- compared to normotensive patients. Five studies reported exact incidences of postoperative cognitive dysfunction.

CONCLUSIONS

This systematic review showed no conclusive association between intraoperative hypotension and the development of postoperative cognitive dysfunction. Given the vast methodological differences of the included studies, the role of intraoperative hypotension in the development of postoperative cognitive dysfunction remains uncertain. Future research into the association between intraoperative hypotension and postoperative cognitive dysfunction should be conducted in a standardized manner.

Orthopedic surgery-induced cognitive dysfunction is mediated by CX3CL1/R1 signaling

Background

Postoperative pain is a common phenomenon after surgery and is closely associated with the development of postoperative cognitive dysfunction (POCD). Persistent pain and systemic inflammation caused by surgery have been suggested as key factors for the development of POCD. Fractalkine (CX3CL1) and its receptor, the CX3C chemokine receptor 1 (CX3CR1), are known to play a key role in pain and inflammation signaling pathways. Recent studies have shown that the regulation of CX3CR1/L1 signaling influences the development of various diseases including neuronal diseases. We determined whether CX3CR1/L1 signaling is a putative therapeutic target for POCD in a mouse model.

Methods

Adult (9–11 weeks) male mice were treated with neutralizing antibody to block CX3CR1/L1 signaling both before and after surgery. Inflammatory and behavioral responses including pain were assessed postoperatively. Also, CX3CR1 mRNA level was assessed. Hippocampal astrocyte activation, Mao B expression, and GABA expression were assessed at 2 days after surgery following neutralizing antibody administration.

Results

The behavioral response indicated cognitive dysfunction and development of pain in the surgery group compared with the control group. Also, increased levels of pro-inflammatory cytokines and CX3CR1 mRNA were observed in the surgery group. In addition, increased levels of GABA and increased Mao B expression were observed in reactive astrocytes in the surgery group; these responses were attenuated by neutralizing antibody administration.

Conclusions

Increased CX3CR1 after surgery is both necessary and sufficient to induce cognitive dysfunction. CX3CR1 could be an important target for therapeutic strategies to prevent the development of POCD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-021-02150-x.

Observation of the impact of the eight-step process combined with the four-track crossover quality control applied to patients with glioma surgery: a randomised trial

Background

At present, surgery is the main treatment for patients with glioma, but there are certain risks in the operation. The traction and stress reaction of related brain tissue during surgery can cause complications such as cerebral edema, which adversely affects the prognosis of patients. The purpose of the present study was to explore the effect of an eight-step process combined with four-track quality control applied to patients undergoing glioma surgery.

Methods

A total of 122 patients undergoing glioma surgery admitted to our hospital from March 2017 to March 2020 were selected and divided into two groups according to the random number table method, each with 61 cases. The control group underwent routine intervention after surgery and the observation group underwent an eight-step process combined with four-track cross-over quality control intervention after surgery. The postoperative rehabilitation effects, cancer-related fatigue, changes in quality of life, and the incidence of complications before and after intervention were compared between the two groups.

Results

The time of catheter removal, the time of first eating, the time of getting out of bed, and the length of hospital stay of the observation group were shorter than those of the control group (P<0.05). In the observation group cognitive fatigue, physical fatigue, and emotional fatigue scores were lower than those of the control group after intervention (P<0.05) and the quality-of-life scores of the observation group after intervention were higher than those of the control group (P<0.05). The total incidence of complications in the observation group was lower than that of the control group (P<0.05).

Conclusions

The eight-step process combined with four-track quality control applied to patients undergoing glioma surgery can reduce cancer-related fatigue, improve quality of life, reduce complications, and promote speedy recovery.

Does propofol ameliorate occurrence of postoperative cognitive dysfunction after general anaesthesia? A protocol of systematic review

BACKGROUND

Postoperative cognitive dysfunction (POCD) is a common condition after general anesthesia (GA). Previous studies have reported that propofol can ameliorate the occurrence of such disorder. However, its results are still inconsistent. Therefore, this systematic review will assess the efficacy and safety of propofol on POCD after GA.

METHODS

Literature sources will be sought from inception to the present in Cochrane Library, MEDLINE, EMBASE, PsycINFO, Web of Science, Scopus, Allied and Complementary Medicine Database, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure for randomized controlled trials (RCTs) assessing the administration of propofol on POCD after GA. All searches will be carried out without limitations to language and publication status. Outcomes comprise of cognitive impairments changes, impairments in short-term memory, concentration, language comprehension, social integration, quality of life, and adverse events. Cochrane risk of bias tool will be utilized to assess study quality. We will evaluate the quality of evidence for each outcome using Grading of Recommendations Assessment, Development and Evaluation approach. A narrative synthesis or a meta-analysis will be undertaken as appropriate.

DISCUSSION

This study will systematically and comprehensively search literature and integrate evidence on the efficacy and safety of propofol on POCD after GA. Our findings will be of interest to clinicians and health-related policy makers.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42020164096.

Comparative short-term outcomes of enhanced recovery after surgery (ERAS) program and non-ERAS traditional care in elderly patients undergoing lumbar arthrodesis: a retrospective study

Background

Enhanced recovery after surgery (ERAS) program is an evidence-based improvement over non-ERAS traditional care. The aim of the present study was to analyze the safety, feasibility, and efficacy of an ERAS program in patients over 70 years undergoing lumbar arthrodesis by comparison with non-ERAS traditional care.

Methods

During January 2018 to December 2018, patients enrolled received non-ERAS traditional care, while the ERAS program was implemented from January to December 2019. Demographic characteristics, comorbidities, surgical data and postoperative recovery parameters were collected from all patients. Postoperative pain scores were evaluated by visual analog scales (VAS). The clinical outcomes were length of stay (LOS), postoperative complications and postoperative pain scores. Compliance results were also collected.

Result

A total of 127 patients were enrolled, including 67 patients in the non-ERAS traditional care group and 60 patients in the ERAS group. The demographic characteristics and comorbidities of the two groups showed no significant differences. The LOS of patients treated with ERAS program (13.6 ± 4.0 days) was significantly less than that of patients treated with non-ERAS traditional care (15.6 ± 3.9 days) (p = 0.034). Complication rate was 8.3% in the ERAS group versus 20.9% in the non-ERAS traditional care group (p = 0.048). VAS (back) in the ERAS group was significantly lower on postoperative day (POD) 1 and POD2. Postoperative recovery parameters were improved in the ERAS group. The overall compliance with the ERAS program was 94%.

Conclusions

Based on our results, ERAS program is safer and more effective for elderly patients over 70 undergoing lumbar arthrodesis than non-ERAS traditional care.

Health-related quality of life and self-reported cognitive function in patients with delayed neurocognitive recovery after radical prostatectomy: a prospective follow-up study

Background

Delayed neurocognitive recovery (DNCR) is a common and serious complication after radical prostatectomy. We hypothesized that patients with DNCR in the early postoperative period would report reduced health-related quality of life (HRQoL) and more cognitive failures 12 months after surgery, compared with patients without DNCR.

Methods

We performed a 12-month follow-up on 367 patients who had been enrolled in a prospective observational trial to study the incidence of DNCR after radical prostatectomy. Patients were screened for preoperative cognitive impairment and depression. We defined DNCR as a decline in cognitive function between days 3 and 5 after surgery, compared with baseline assessments. We evaluated HRQoL and cognitive failures 12 months after surgery with the 36-item Short Form Health Survey and the Cognitive Failures Questionnaire. General linear models were used to analyze associations of DNCR with HRQoL and cognitive failures.

Results

Delayed neurocognitive recovery in the early postoperative period was significantly associated with self-reported cognitive failures (B for no DNCR =  − 0.411 [95% CI: − 0.798;0.024], p = 0.038), but not with physical (B = 0.082 [95% CI: − 0.021;0.186], p = 0.118) or mental HRQoL (B =  − 0.044 [95% CI: − 0.149;0.062], p = 0.417) 12 months after surgery. Preoperative depression screening scores were significantly associated with self-reported cognitive failures and both physical and mental HRQoL 12 months after surgery.

Conclusions

Delayed neurocognitive recovery in the early period after radical prostatectomy has a long-term impact on patients’ daily lives by impairing memory, attention, action, and perception. Therefore, prevention of DNCR must be a priority for physicians and researchers. Consequent preoperative screening for depressive symptoms may facilitate early psycho-oncological intervention to improve postoperative HRQoL.

Trials registrationDRKS00010014, date of registration: 21.03.2016, retrospectively registered.

The Role of Perioperative Sleep Disturbance in Postoperative Neurocognitive Disorders

Postoperative neurocognitive disorder (PND) increases the length of hospital stay, mortality, and risk of long-term cognitive impairment. Perioperative sleep disturbance is prevalent and commonly ignored and may increase the risk of PND. However, the role of perioperative sleep disturbances in PND remains unclear. Nocturnal sleep plays an indispensable role in learning, memory, and maintenance of cerebral microenvironmental homeostasis. Hospitalized sleep disturbances also increase the incidence of postoperative delirium and cognitive dysfunction. This review summarizes the role of perioperative sleep disturbances in PND and elucidates the potential mechanisms underlying sleep-deprivation-mediated PND. Activated neuroinflammation and oxidative stress; impaired function of the blood-brain barrier and glymphatic pathway; decreased hippocampal brain-derived neurotrophic factor, adult neurogenesis, and sirtuin1 expression; and accumulated amyloid-beta proteins are associated with PND in individuals with perioperative sleep disorders. These findings suggest that the improvement of perioperative sleep might reduce the incidence of postoperative delirium and postoperative cognitive dysfunction. Future studies should further investigate the role of perioperative sleep disturbance in PND.

Evaluation of the efficiency of propofol versus isoflurane anesthesia interventions in treating elderly patients with postoperative cognitive dysfunction: A protocol for systematic review and meta-analysis

BACKGROUND

The aim of this study was to systematically evaluate the efficiency of propofol versus isoflurane anesthesia interventions in treating elderly patients with postoperative cognitive dysfunction.

METHODS

We performed an in-depth search in the PubMed, EMBASE, Cochrane Library, Chongqing VIP, WanFang, China National Knowledge Infrastructure, and SinoMed. Additionally, we reviewed the reference lists of included studies. Two independent authors examined the quality of the study and the quality of the extracted data. Regarding the dichotomous outcomes, we stated the results as relative risk, with 95% confidence intervals. We further expressed incessant outcomes as mean difference with a confidence level of 95%.

RESULTS

The findings of the study will be published in a peer-reviewed journal.

CONCLUSION

Findings of this study will help in providing insight to establish if propofol is a suitable intervention to treat postoperative cognitive dysfunction in elderly patients.

SYSTEMATIC REVIEW REGISTRATION NUMBER

INPLASY202090042.

SIRT1 mediates improvement of cardiac surgery-induced postoperative cognitive dysfunction via the TLR4/NF-κB pathway

OBJECTIVES

Clinically, there is no effective therapy for postoperative cognitive dysfunction (POCD). Inflammation after surgery is closely associated with POCD.

METHODS

In this study, we explored the role of sirtuin 1 (SIRT1) in POCD. POCD in mice was induced by cardiac surgery. The mRNA and protein levels of related genes were determined by real-time polymerase chain reaction and western blot, respectively. Plasma concentrations of inflammatory factors were measured using an ELISA kit. Novel object and novel location recognition tests were carried out to measure recognition ability. The Morris water maze (MWM) test was performed to measure learning and memory ability.

RESULTS

There was a clear decrease in SIRT1 expression after POCD. The SIRT1 activator SRT1720 promoted recognition, learning, and memory ability of mice with POCD. Moreover, SRT1720 treatment greatly inhibited plasma inflammatory cytokine levels and TLR4 and P65 protein expression in the hippocampus of POCD mice. The effect of SRT1720 on POCD was in a TLR4-dependent manner.

CONCLUSIONS

SIRT1 mediates the improvement of cardiac surgery-induced postoperative cognitive dysfunction via the TLR4/NF-κB pathway.

Astaxanthin protects cognitive function of vascular dementia

OBJECTIVE

The purpose of this study was to evaluate the effect of astaxanthin (AST) on cognition function, inflammatory response and oxidative stress in vascular dementia (VD) mice.

METHOD

VD mice model was established by left unilateral common carotid arteries occlusion (LUCCAO). Following LUCCAO, AST was intragastrically administered for 30 days. Object recognition test and morris water maze test were used to evaluate cognitive function. Hematoxylin and eosin staining was performed to observe the hippocampal neuron structure. Enzyme-linked immunosorbent assay kit and bicinchoninic acid kit were respectively adopted to measure IL-1β and IL-4 protein expression and superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in hippocampus and prefrontal cortex.

RESULTS

AST improved the discrimination ability of VD mice. The escape latency and path length of VD mice treated with AST were dramatically reduced. Besides, AST 200 mg/kg enhanced crossing platform time and the number of times crossing the platform quadrant, and alleviated the morphological impairment in VD mice. Moreover, we found that AST inhibited IL-1β expression and MDA content, whereas promoted IL-4 expression and SOD activity in a dose-dependent manner.

CONCLUSION

AST could improve cognitive impairment and hippocampal neurons in VD mice, which may be related to suppression of inflammatory response and oxidative stress.

Association between increased neutrophil-to-lymphocyte ratio and postoperative delirium in elderly patients with total hip arthroplasty for hip fracture

BACKGROUND

Delirium is a common complication in elderly patients with total hip arthroplasty (THA) for hip fracture. The mechanism of postoperative delirium (POD) is associated with the neuroinflammatory process. The aim of this study was to the incidence and perioperative risk factors of POD and investigate whether NLR could serve as a potential marker for POD in elderly patients with THA for hip fracture.

METHODS

This was a multicenter prospective study, we included elderly patients with THA for hip fracture under general anesthesia. Receiver operating characteristic (ROC) curve was performed to identify the optimal cut point of NLR for POD. The relationship between NLR and POD was analyzed by multivariable analysis.

RESULTS

Seven hundred eighty patients (mean age 73.33 ± 7.66) were eligible for inclusion in the study. 23.33% (182/780) of patients had POD. ROC curve analysis showed that the optimal cut point of NLR for POD was NLR ≥ 3.5. Compared with no POD, higher NLR, older age, diabetes, and higher neutrophil count were more likely in patients with POD(P < 0.05). Multivariate logistic regression analysis showed that NLR ≥ 3.50 [adjusted odds ratio(aOR), 3.93; confidence interval (CI), 2.47-6.25; P < 0.001)], older age (aOR, 1.04; 95%CI, 1.02-1.07; P = 0.001), diabetes (aOR, 1.58; 95% CI, 1.06-2.36; P = 0.025),higher neutrophil count (aOR, 1.25; 95%CI, 1.15-1.35; P < 0.001) were associated with increased risk of POD.

CONCLUSIONS

Older age, diabetes, higher neutrophil count, and NLR ≥ 3.5 were independent risk factors for POD, and NLR can be used as a potential marker for prediction of delirium in elderly patients with THA for hip fracture.

Investigating Association between Intraoperative Hypotension and Postoperative Neurocognitive Disorders in Non-Cardiac Surgery: A Comprehensive Review

Postoperative delirium (POD) and postoperative cognitive decline (deficit) (POCD) are related to a higher risk of postoperative complications and long-term disability. Pathophysiology of POD and POCD is complex, elusive and multifactorial. Intraoperative hypotension (IOH) constitutes a frequent and vital health hazard in the perioperative period. Unfortunately, there are no international recommendations in terms of diagnostics and treatment of neurocognitive complications which may arise from hypotension-related hypoperfusion. Therefore, we performed a comprehensive review of the literature evaluating the association between IOH and POD/POCD in the non-cardiac setting. We have concluded that available data are quite inconsistent and there is a paucity of high-quality evidence convincing that IOH is a risk factor for POD/POCD development. Considerable heterogeneity between studies is the major limitation to set up reliable recommendations regarding intraoperative blood pressure management to protect the brain against hypotension-related hypoperfusion. Further well-designed and effectively-performed research is needed to elucidate true impact of intraoperative blood pressure variations on postoperative cognitive functioning.

Current Evidence Regarding Biomarkers Used to Aid Postoperative Delirium Diagnosis in the Field of Cardiac Surgery-Review

Postoperative cognitive disorders after cardiac surgery may manifest as postoperative delirium (POD) or later as postoperative cognitive dysfunction (POCD). The incidence of POD after cardiac surgery ranges from 16% to 73%. In contrast to POD, POCD is usually diagnosed after the discharge from hospital, with an incidence of 30 to 70% of cases, very often noticed only by close relative or friends, decreasing after six (20–30%) and twelve (15–25%) months after surgery. Perioperative cognitive disorders are associated with adverse short- and long-term effects, including increased morbidity and mortality. Due to the complexity of delirium pathomechanisms and the difficulties in the diagnosis, researchers have not yet found a clear answer to the question of which patient will be at a higher risk of developing delirium. The risk for POD and POCD in older patients with numerous comorbidities like hypertension, diabetes, and previous ischemic stroke is relatively high, and the predisposing cognitive profile for both conditions is important. The aim of this narrative review was to identify and describe biomarkers used in the diagnosis of delirium after cardiac surgery by presenting a search through studies regarding this subject, which have been published during the last ten years. The authors discussed brain-derived biomarkers, inflammation-related biomarkers, neurotransmitter-based biomarkers, and others. Work based on inflammation-related biomarkers, which are characterized by the low cost of implementation and the effectiveness of delirium diagnosis, seems to be the closest to the goal of discovering an inexpensive and effective marker. Currently, the use of a panel of tests, and not a single biomarker, brings us closer to the discovery of a test, or rather a set of tests ideal for the diagnosis of delirium after cardiac surgery.

Social Cognitive Dysfunction in Elderly Patients After Anesthesia and Surgery

Extensive studies have revealed that cognitive processing was impaired after anesthesia and surgery, particularly for the elderly patients. However, most of the existing studies focused on the general cognitive deficits (e.g., delayed neuro-cognitive recovery and POCD). Although diagnosis of social abilities has been used in various clinical fields, few studies have investigated the potential deficit on social cognition after anesthesia and surgery. The current study examined whether there was any social cognitive dysfunction after anesthesia and surgery. We achieved this by taking biological motion (BM) as the stimuli of interest, the perception of which has been taken as the hallmark of social cognition. The elderly patients (aged ≥ 60 years) were required to judge whether an upright BM stimulus appeared among the dynamic noises to test their social cognition, as well as do a Mini-Mental State Examination to test their general cognition. The two tests were performed at both 1-day before and 7-day after the surgery. Results showed that 31.25% of patients exhibited BM perception deficit after anesthesia and surgery relative to before anesthesia and surgery, implying that social cognitive dysfunction existed. Meanwhile, social cognitive dysfunction was independent from delayed neurocognitive recovery.

Postoperative cognitive dysfunction in elderly patients undergoing hip arthroplasty

Even after successful hip arthroplasty, elderly patients who have undergone this procedure remain subject to cognitive decline and may collectively develop postoperative cognitive dysfunction (POCD). However, no consensus exists as to the risk factors resulting in a higher likelihood that a patient may present with this complication, and the aetiology of POCD is not well understood. We conducted a systematic review of papers concerning the influence of POCD-related risk factors in patients undergoing hip arthroplasty but limited the literature search to papers in English. A systematic and electronic search for manuscripts in the PubMed database was performed in order to identify all studies in which the risk factors for POCD were investigated. Articles were also obtained from the authors' files. Keywords for the search were postoperative cognitive dysfunction/change/impairment/decline/deficit, elderly/older/aged patients, and hip arthroplasty/replacement surgery. The evidence published to date suggests that POCD is a multifactorial disease, which includes an individual patient's characteristics, surgery, type of anaesthesia, and pain levels. All of these factors can increase the risk of POCD incidence. There are a number of factors that appear to influence the risk of early cognitive dysfunction after hip arthroplasty. Nevertheless, the specific mechanism and explicit risk factors associated with this cognitive dysfunction are not completely understood. Hip arthroplasty has made it possible for older patients to find relief from pain and improve their function, whereas it also increases the risk for suffering POCD that may affect these patients' quality of life and increase their mortality. Therefore, it is worthwhile investigating the mechanism of POCD in future studies in order to prevent and treat this condition.

Effects of PYRIN-containing Apaf1-like protein 1 on isoflurane-induced postoperative cognitive dysfunction in aged rats

Postoperative cognitive dysfunction (POCD) is a prevalent neurocognitive disorder following surgery and anesthesia, particularly in elderly patients. Isoflurane is a widely used anesthetic agent, which is associated with the development of POCD; however, the precise mechanisms remain unclear. In the present study, aged rats were exposed to 2% isoflurane to establish a POCD model. The expression of PYRIN-containing Apaf1-like protein 1 (PYPAF1) was knocked down using a lentivirus containing specific short hairpin RNA. Subsequently, the spatial learning ability of rats was assessed using the Morris water maze. In addition, mRNA and protein expression levels were detected using reverse transcription-quantitative PCR and western blot analysis, respectively. Immunofluorescence double staining was also used to determine the expression of PYPAF1 and Iba-1 in the hippocampus. Neural apoptosis was observed using TUNEL-NeuN double staining. The results revealed that isoflurane exposure impaired the spatial learning ability of rats, while PYPAF1 knockdown alleviated cognitive impairment. In addition, isoflurane exposure induced activation of the PYPAF1 inflammasome, as evidenced by elevated expression of PYPAF1 and apoptosis-associated speck-like protein containing a caspase recruitment domain, while silencing of PYPAF1 partially reversed this effect. Furthermore, isoflurane exposure promoted the activation of microglia and caspase-1, and the secretion of interleukin (IL)-1β and IL-18, all of which were alleviated following PYPAF1 silencing. Moreover, isoflurane exposure induced neuronal apoptosis, elevated the levels of Bax and cleaved caspase-3, and inhibited the expression of Bcl-2; all of these effects were partially abrogated following PYPAF1 silencing. In conclusion, the results of the present study indicated that PYPAF1 silencing partially abolished isoflurane-induced cognitive impairment, neuroinflammation and neuronal apoptosis. Therefore, PYPAF1 may be a potential therapeutic target for treatment of POCD.

Hippocampal complement C3 might contribute to cognitive impairment induced by anesthesia and surgery

Postoperative cognitive dysfunction is a well-recognized complication after major surgery in the elderly, but its pathophysiological mechanism is not fully understood. In the present study, we used liquid chromatography-tandem mass spectrometry combined with tandem mass tags to identify differentially expressed proteins and perform further functional studies on protein of interest. Here, we showed that hippocampal complement C3 was significantly upregulated after surgery, which was accompanied by marked decreases in synaptic related proteins and density. In aged patients undergoing gastrointestinal surgery, we also found significantly increased plasma level of C3b postoperatively and were negatively associated with cognitive performance. Notably, selective inhibition of complement C3 by compstatin was able to rescue synaptic and cognitive impairments induced by surgery in aged mice. Collectively, our study confirms that surgery can induce cognitive impairments, and the possible mechanisms might be related to abnormal complement signaling and synaptic disruption.

Exosomes of Antler Mesenchymal Stem Cells Improve Postoperative Cognitive Dysfunction in Cardiopulmonary Bypass Rats through Inhibiting the TLR2/TLR4 Signaling Pathway

Postoperative cognitive dysfunction (POCD) is a severe complication of cardiopulmonary bypass (CPB) and has common characteristics such as acute cognitive dysfunction, impaired memory, and inattention. Mesenchymal stem cells (MSCs) are multipotent cells that have therapeutic potentials mainly through paracrine action via secreting growth factors and cytokines. Exosomes are one of the important paracrine factors and have been reported as potential cell-free therapy for the treatment of autoimmune and central nervous system disorders. In this study, we examined exosomes derived from antler MSCs (AMSCs) of POCD rats after CPB and evaluated their potential regulatory mechanisms. AMSC-derived exosomes reduced neurological damage and brain damage and prevent apoptosis in CPB rats. Furthermore, AMSC-derived exosomes were found to reduce hippocampal neuronal apoptosis and the expression of TLR2, TLR4, MyD88, and NF-κB in CPB rats. However, the above effects of AMSC-derived exosomes on CPB rats were abolished partially by toll-like receptor 2/4 (TLR2/TLR4) agonist (LPS-EB). In conclusion, AMSC-derived exosomes can improve cognitive function in CPB rats through inhibiting the TLR2/TLR4 signaling pathway.

Aliskiren and captopril improve cognitive deficits in poorly controlled STZ-induced diabetic rats via amelioration of the hippocampal P-ERK, GSK3β, P-GSK3β pathway

Learning and memory deficits are obvious symptoms that develop over time in patients with poorly controlled diabetes. Hyperactivity of the renin-angiotensin system (RAS) is directly associated with β-cell dysfunction and diabetic complications, including cognitive impairment. Here, we investigated the protective and molecular effects of two RAS modifiers, aliskiren; renin inhibitor and captopril; angiotensin converting enzyme inhibitor, on cognitive deficits in the rat hippocampus. Injection of low dose streptozotocin for 4 days resulted in type 1 diabetes. Then, poorly controlled diabetes was mimicked with ineffective daily doses of insulin for 4 weeks. The hyperglycaemia and pancreatic atrophy caused memory disturbance that were identifiable in behavioural tests, hippocampal neurodegeneration, and the following significant changes in the hippocampus, increases in the inflammatory marker interleukin 1β, cholinesterase, the oxidative stress marker malondialdehyde and protein expression of phosphorylated extracellular-signal-regulated kinase and glycogen synthase kinase-3 beta versus decrease in the antioxidant reduced glutathione and protein expression of phosphorylated glycogen synthase kinase-3 beta. Blocking RAS with either drugs along with insulin amended all previously mentioned parameters. Aliskiren stabilized the blood glucose level and restored normal pancreatic integrity and hippocampal malondialdehyde level. Aliskiren showed superior protection against the hippocampal degeneration displayed in the earlier behavioural modification in the passive avoidance test, and the aliskiren group outperformed the control group in the novel object recognition test. We therefore conclude that aliskiren and captopril reversed the diabetic state and cognitive deficits in rats with poorly controlled STZ-induced diabetes through reducing oxidative stress and inflammation and modulating protein expression.