Intravenous parecoxib for early postoperative cognitive dysfunction in elderly patients: evidence from a meta-analysis

Sevoflurane-induced cognitive effect on α7-nicotine receptor and M1 acetylcholine receptor expression in the hippocampus of aged rats

BACKGROUND

Sevoflurane treatment increases the incidence of postoperative cognitive dysfunction (POCD), and patients with POCD show a decline in cognitive abilities compared to preoperative levels.

OBJECTIVES

This study aimed to investigate whether the activation of α7 nicotinic acetylcholine receptor (α7nAChR) and the expression of M1 acetylcholine receptor (mAChR M1) in the hippocampus affects the cognitive function of aged rats.

METHODS

Forty-eight Sprague-Dawley (SD) rats of 1-week- and 12-months-old were divided into eight groups: four groups for α7nAChR and four groups for mAChR M1, respectively. All SD rats received 1.0-02% sevoflurane for α7nAChR and 1.0-02% sevoflurane for mAChR M1 for 2-6 h, respectively. The Y-maze test was used to assess the ability to learn and memory after receiving sevoflurane for 7 days at the same moment portion. RT-PCR was used to determine the expression of α7nAChR and mAChR M1 in the hippocampus of rats.

RESULTS

The α7nAChR mitigated the formation of sevoflurane-induced memory impairment by modulating the translocation of NR2B from the intracellular reservoir to the cell surface reservoir within the hippocampus. Next, sevoflurane-induced decline of cognitive function and significantly decreased mAChR M1 expression at mRNA levels.

CONCLUSION

α7nAChR regulates the trafficking of NR2B in the hippocampus of rats via the Src-family tyrosine kinase (SFK) pathway. This regulation is associated with cognitive deficits induced by sevoflurane in hippocampal development. Sevoflurane affects the cognitive function of rats by suppressing the mAChR M1 expression at mRNA levels in the hippocampus.

miR-206-3p Targets Brain-Derived Neurotrophic Factor and Affects Postoperative Cognitive Function in Aged Mice

Postoperative cognitive dysfunction (POCD) occurs after surgery and severely impairs patients' quality of life. Finding POCD-associated variables can aid in its diagnosis and prognostication. POCD is associated with noncoding RNAs, such as microRNAs (miRNAs), involved in metabolic function, immune response alteration, and cognitive ability impairment; however, the underlying mechanisms remain unclear. The aim of this study was to investigate hub miRNAs (i.e., miRNAs that have an important regulatory role in diseases) regulating postoperative cognitive function and the associated mechanisms. Hub miRNAs were identified by bioinformatics, and their expression in mouse hippocampus tissues was determined using real-time quantitative polymerase chain reaction. Hub miRNAs were overexpressed or knocked down in cell and animal models to test their effects on neuroinflammation and postoperative cognitive function. Six differentially expressed hub miRNAs were identified. miR-206-3p was the only broadly conserved miRNA, and it was used in follow-up studies and animal experiments. Its inhibitors reduced the release of proinflammatory cytokines in BV-2 microglia by regulating its target gene, brain-derived neurotrophic factor (BDNF), and the downstream signaling pathways. miR-206-3p inhibition suppressed microglial activation in the hippocampi of mice and improved learning and cognitive decline. Therefore, miR-206-3p significantly affects POCD, implying its potential as a therapeutic target.

Postoperative cognitive dysfunction: Review of pathophysiology, diagnostics and preventive strategies

Postoperative cognitive impairment is a common disorder after major surgery. Advances in medicine and treatment have resulted in an increasingly ageing population undergoing major surgical procedures. Since age is the most important risk factor for postoperative cognitive decline, it is not surprising that impairment of cognitive functions after surgery was recorded in almost a third of elderly patients. Postoperative cognitive dysfunction is part of the spectrum of postoperative cognitive impairment and researchers often confuse it with postoperative delirium and delayed neurocognitive recovery. This is the cause of great differences in the results of research that is focused on the incidence and possible prevention of postoperative cognitive dysfunction. In this review, we focused on current recommendations for a uniform nomenclature of postoperative cognitive impairment and diagnosis of postoperative cognitive dysfunction, the presumed pathophysiology of postoperative cognitive dysfunction and recommendations for its treatment and possible prevention strategies.

The m6A Reader YTHDF1 Improves Sevoflurane-Induced Neuronal Pyroptosis and Cognitive Dysfunction Through Augmenting CREB-BDNF Signaling

Sevoflurane is one of the most widely used anesthetics in surgery which is the main cause of postoperative cognitive dysfunction (POCD). Previous reports confirmed that YTHDF1 is differently expressed in sevoflurane-induced POCD, while the roles and mechanistic details remain unclear. The molecular expressions were assessed using qRT-PCR, western blot, immunofluorescence and immunohistochemistry. Pathological change in the hippocampus tissues was analyzed using HE staining. Cognitive ability in rats was measured using MWM test. Hippocampal neuronal viability and apoptosis were measured by MTT assay and flow cytometry, respectively. The levels of pro-inflammatory cytokines were assessed using ELISA. The interaction between YTHDF1 and CREB was analyzed by RNA immunoprecipitation assay. YTHDF1 was significantly decreased in hippocampus tissues by sevoflurane exposure, and its overexpression could improve sevoflurane-induced neuron damage and cognitive dysfunction. Meanwhile, YTHDF1 upregulation repressed sevoflurane-induced activation of NLRP3 inflammation and pyroptosis in hippocampus tissues. Subsequently, YTHDF1 directly interacted to CREB mRNA to augment its stability and translation via a m6A-dependent manner, thus activating CREB/BDNF pathway. In addition, the inactivation of CREB/BDNF pathway could reverse the protective effects of YTHDF1 overexpression on sevoflurane-mediated neuronal damage and pyroptosis. These findings revealed that YTHDF1 improved sevoflurane-induced neuronal pyroptosis and cognitive dysfunction through activating CREB-BDNF signaling.

Neuroinflammation: The central enabler of postoperative cognitive dysfunction

The proportion of advanced age patients undergoing surgical procedures is on the rise owing to advancements in surgical and anesthesia technologies as well as an overall aging population. As a complication of anesthesia and surgery, older patients frequently suffer from postoperative cognitive dysfunction (POCD), which may persist for weeks, months or even longer. POCD is a complex pathological process involving multiple pathogenic factors, and its mechanism is yet unclear. Potential theories include inflammation, deposition of pathogenic proteins, imbalance of neurotransmitters, and chronic stress. The identification, prevention, and treatment of POCD are still in the exploratory stages owing to the absence of standardized diagnostic criteria. Undoubtedly, comprehending the development of POCD remains crucial in overcoming the illness. Neuroinflammation is the leading hypothesis and a crucial component of the pathological network of POCD and may have complex interactions with other mechanisms. In this review, we discuss the possible ways in which surgery and anesthesia cause neuroinflammation and investigate the connection between neuroinflammation and the development of POCD. Understanding these mechanisms may likely ensure that future treatment options of POCD are more effective.

Systemic inflammation, neuroinflammation and perioperative neurocognitive disorders

Perioperative neurocognitive disorder (PND) is a common disorder following anesthesia and surgery, especially in the elderly. The complex cellular and molecular processes are involved in PND, but the underlying pathogenesis of which remains inconclusive due to conflicting data. A growing body of evidence has been shown that perioperative systemic inflammation plays important roles in the development of PND. We reviewed the relevant literature retrieved by a search in the PubMed database (on July 20, 2023). The search terms used were "delirium", "post operative cognitive dysfunction", "perioperative neurocognitive disorder", "inflammation" and "systemic", alone and in combination. All articles identified were English-language, full-text papers. The ones cited in the review are those that make a substantial contribution to the knowledge about systemic inflammation and PNDs. The aim of this review is to bring together the latest evidence for the understanding of how perioperative systemic inflammation mediates neuroinflammation and brain injury, how the inflammation is regulated and how we can translate these findings into prevention and/or treatment for PND.

The Efficacy and Safety of Parecoxib Multimodal Preemptive Analgesia in Artificial Joint Replacement: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Postoperative pain after artificial joint replacement is intense and remains an unsolved problem. Some studies have shown that parecoxib can provide better analgesia in postoperative multimodal analgesia, however, doubts arise about whether its multimodal preemptive analgesia can reduce postoperative pain.

OBJECTIVES

The purpose of this systematic review and meta-analysis was to evaluate the impact of preoperative injection of parecoxib on postoperative pain in patients undergoing artificial joint replacement.

STUDY DESIGN

Systematic review and meta-analysis.

SETTING

Embase, PubMed, Cochrane Library, CNKI, VIP, Wangfang databases were searched to identify relevant randomized controlled trials. The last search was in May 2022.

METHODS

Randomized controlled trials of efficacy and adverse reactions of intra-operative and postoperative injection of parecoxib in artificial joint replacement were collected. The primary outcome was postoperative visual analog scale scores and the secondary outcomes included cumulative postoperative opioid consumption and incidence of adverse reactions. Using the Cochrane systematic review method to screen the studies, evaluate the quality of the included studies, and extract feature information, RevMan 5.4 software performs a meta-analysis of the corresponding research indicators.

RESULTS

In total, nine studies were involved in the meta-analysis with 667 patients. The trial and control group were given the same dose of parecoxib or placebo at the same time point before and after surgery. The results showed that compared with the control group, the trial group is associated with substantially reduced visual analog scale scores in 24, 48 h at rest (P < 0.05), visual analog scale scores in 24, 48, 72 h at movement (P < 0.05), dose of opioid need in trial group is notably lower than that in control group (P < 0.05), but shows no obvious effect on visual analog scale scores in 72 h at rest, and adverse events (P > 0.05).

LIMITATIONS

The major limitation of this meta-analysis relates to some low-quality studies.

CONCLUSIONS

Our results support parecoxib multimodal preemptive analgesia in reducing postoperative acute pain in hip and knee replacement patients, and reduces cumulative opioid consumption without increasing the risk of adverse drug events. Its multimodal preemptive analgesia is safe and effective in hip and knee replacement.

PROSPERO REGISTRATION

CRD42022379672.

Effects of anesthetic adjunctive agents on postoperative cognitive dysfunction in elderly patients undergoing noncardiac surgery: A Bayesian network meta-analysis

BACKGROUND

Elderly patients are prone to postoperative cognitive dysfunction (POCD). The comparison of the effects of anesthetic adjuvant drugs on POCD in elderly patients undergoing noncardiac surgery remains controversial.

METHODS

The final search took place on June 10, 2023. Randomized controlled trials including ketamine, ulinastatin, dexmedetomidine, parecoxib, and midazolam on the prevention and treatment of POCD in elderly undergoing noncardiac surgery were collected. A Bayesian network meta-analysis was performed to quantitatively combine the evidence.

RESULTS

A total of 35 randomized trials were finally included in this systematic review, and the overall risk of bias is Allocation concealment. These anesthetic adjuvant drugs did not show significant differences in preventing POCD on postoperative days 1 and 7 compared with each other, but ulinastatin may be more effective in preventing POCD than dexmedetomidine [odds ratio (OR) = 0.28, 95% confidence interval (CI) = (0.10, 0.71)] and parecoxib [OR = 0.3, 95% CI = (0.10, 0.82 on postoperative day 3. The efficiency ranking results also find that ulinastatin and ketamine might provide better effects regarding POCD prevention.

CONCLUSIONS

Ketamine and ulinastatin might have better effects in preventing POCD in elderly patients undergoing noncardiac surgery. Our meta-analysis provided evidence for the use of ulinastatin and ketamine in the prevention of POCD in elderly patients undergoing noncardiac surgery.

Acute pain management and long term outcomes

PURPOSE OF REVIEW

The acute inflammatory reaction induced by tissue trauma causes pain but also promotes recovery. Recovery is highly variable among peoples. Effective acute pain (AP) management is very important but remains suboptimal what could affect long term outcomes. The review questions the impact of either failure or effectiveness of AP treatments and the choice of analgesic drugs on different long-term outcomes after tissue trauma.

RECENT FINDINGS

Pain control during mobilization is mandatory to reduce the risk of complications which exacerbate and prolong the inflammatory response to trauma, impairing physical recovery. Common analgesic treatments show considerable variability in effectiveness among peoples what argues for an urgent need to develop personalized AP management, that is, finding better responders to common analgesics and targeting challenging patients for more invasive procedures. Optimal multimodal analgesia to spare opioids administration remains a priority as opioids may enhance neuroinflammation, which underlies pain persistence and precipitates neurocognitive decline in frail patients. Finally, recent findings demonstrate that AP treatments which modulate nociceptive and inflammatory pain should be used with caution as drugs which inhibit inflammation like nonsteroidal antiinflammatory drugs and corticoids might interfere with natural recovery processes.

SUMMARY

Effective and safe AP management is of far greater importance than previously realized. Evidence of suboptimal AP management in many patients and recent reports pointing out the impact of current treatments on long term outcomes argue for further research in the field.

Ac-YVAD-cmk ameliorated sevoflurane-induced cognitive dysfunction and revised mitophagy impairment

It is common for elderly patients to develop postoperative cognitive dysfunction (POCD), but the pathophysiological mechanisms have not yet been fully explored. NLRP3 inflammasome activation and mitophagy impairment was involved in neurodegenerative disease. This study investigated the interaction of NLRP3 inflammasome and mitophagy in sevoflurane-induced cognitive dysfunction. We found that sevoflurane induced cleaved caspase-1 level, IL-1β and IL-18 maturation, and activated NLRP3 inflammasome in aged mice and the primary hippocampus neuron. The cleaved caspase-1 was demonstrated in microglia of hippocampus. Ac-YVAD-cmk, a selected caspase-1 inhibitor, reduced the expression of cleaved caspase-1, IL-1β, IL-18 and NLRP3 inflammasome activation induced by sevoflurane. Ac-YVAD-cmk ameliorated learning ability impairment in aged mice induced by sevoflurane using Morris water maze. Moreover, Ac-YVAD-cmk reversed the mitophagy flux dysfunction induced by sevoflurane in aged mice by western blotting, immunostaining and mt-Keima reporters. For the first time, we found caspase-1 inhibitor mitigated mitochondria dysfunction and revised mitophagy impairment induced by sevoflurane.

Hippocampal gene expression patterns in Sevoflurane anesthesia associated neurocognitive disorders: A bioinformatic analysis

Background

Several studies indicate general anesthetics can produce lasting effects on cognitive function. The commonly utilized anesthetic agent Sevoflurane has been implicated in neurodegenerative processes. The present study aimed to identify molecular underpinnings of Sevoflurane anesthesia linked neurocognitive changes by leveraging publically available datasets for bioinformatics analysis.

Methods

A Sevoflurane anesthesia related gene expression dataset was obtained. Sevoflurane related genes were obtained from the CTD database. Neurocognitive disorders (NCD) related genes were downloaded from DisGeNET and CTD. Intersecting differentially expressed genes between Sevoflurane and NCD were identified as cross-talk genes. A protein-protein interaction (PPI) network was constructed. Hub genes were selected using LASSO regression. Single sample gene set enrichment analysis; functional network analysis, pathway correlations, composite network analysis and drug sensitivity analysis were performed.

Results

Fourteen intersecting cross-talk genes potentially were identified. These were mainly involved in biological processes including peptidyl-serine phosphorylation, cellular response to starvation, and response to gamma radiation, regulation of p53 signaling pathway, AGE-RAGE signaling pathway and FoxO signaling. Egr1 showed a central role in the PPI network. Cdkn1a, Egr1, Gadd45a, Slc2a1, and Slc3a2 were identified as important or hub cross-talk genes. Among the interacting pathways, Interleukin-10 signaling and NF-kappa B signaling enriched among Sevoflurane-related DEGs were highly correlated with HIF-1 signaling enriched in NCD-related genes. Composite network analysis showed Egr1 interacted with AGE-RAGE signaling and Apelin signaling pathways, Cdkn1a, and Gadd45a. Cdkn1a was implicated in in FoxO signaling, PI3K-Akt signaling, ErbB signaling, and Oxytocin signaling pathways, and Gadd45a. Gadd45a was involved in NF-kappa B signaling and FoxO signaling pathways. Drug sensitivity analysis showed Egr1 was highly sensitive to GENIPIN.

Conclusion

A suite of bioinformatics analysis revealed several key candidate hippocampal genes and associated functional signaling pathways that could underlie Sevoflurane associated neurodegenerative processes.

Perioperative neurocognitive disorders: A narrative review focusing on diagnosis, prevention, and treatment

Perioperative neurocognitive disorders (NCDs) refer to neurocognitive abnormalities detected during the perioperative periods, including preexisting cognitive impairment, preoperative delirium, delirium occurring up to 7 days after surgery, delayed neurocognitive recovery, and postoperative NCD. The Diagnostic and Statistical Manual of Mental Disorders‐5th edition (DSM‐5) is the golden standard for diagnosing perioperative NCDs. Given the impracticality of using the DSM‐5 by non‐psychiatric practitioners, many diagnostic tools have been developed and validated for different clinical scenarios. The etiology of perioperative NCDs is multifactorial and includes predisposing and precipitating factors. Identifying these risk factors is conducive to preoperative risk stratification and perioperative risk reduction. Prevention for perioperative NCDs should include avoiding possible contributors and implementing nonpharmacologic and pharmacological interventions. The former generally includes avoiding benzodiazepines, anticholinergics, prolonged liquid fasting, deep anesthesia, cerebral oxygen desaturation, and intraoperative hypothermia. Nonpharmacologic measures include preoperative cognitive prehabilitation, comprehensive geriatric assessment, implementing fast‐track surgery, combined use of regional block, and sleep promotion. Pharmacological measures including dexmedetomidine, nonsteroidal anti‐inflammatory drugs, and acetaminophen are found to have beneficial effects. Nonpharmacological treatments are the first‐line measures for established perioperative NCDs. Pharmacological treatments are still limited to severely agitated or distressed patients.

Effect of Anesthesia on Oligodendrocyte Development in the Brain

Oligodendrocytes (OLs) participate in the formation of myelin, promoting the propagation of action potentials, and disruption of their proliferation and differentiation leads to central nervous system (CNS) damage. As surgical techniques have advanced, there is an increasing number of children who undergo multiple procedures early in life, and recent experiments have demonstrated effects on brain development after a single or multiple anesthetics. An increasing number of clinical studies showing the effects of anesthetic drugs on the development of the nervous system may mainly reside in the connections between neurons, where myelin development will receive more research attention. In this article, we review the relationship between anesthesia exposure and the brain and OLs, provide new insights into the development of the relationship between anesthesia exposure and OLs, and provide a theoretical basis for clinical prevention of neurodevelopmental risks of general anesthesia drugs.

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.

Progress in Research on the Effect of Melatonin on Postoperative Cognitive Dysfunction in Older Patients

Postoperative cognitive dysfunction (POCD) is a common complication of the central nervous system in elderly patients after operation. It will prolong the length of stay, reduce the independence and quality of daily life, and increase the risk of death. However, at present, there is a lack of safe and effective ideal drugs for the prevention and treatment of POCD. Melatonin is one of the hormones secreted by the pineal gland of the brain, which has the functions of regulating circadian rhythm, anti-inflammation, anti-oxidation, anti-apoptosis, and so on. Some recent studies have shown that MT can prevent and treat POCD by adjusting circadian rhythm, restoring cholinergic system function, neuroprotection, and so on. This article will introduce POCD, melatonin and the mechanism of melatonin on POCD, respectively, to provide a basis for clinical prevention and treatment of POCD in the elderly.

Nonopioid Analgesics for the Perioperative Geriatric Patient: A Narrative Review

Management of acute perioperative pain in the geriatric patient can be challenging as the physiologic and pharmacokinetic changes associated with aging may predispose older patients to opioid-related side effects. Furthermore, elderly adults are more susceptible to postoperative delirium and postoperative cognitive dysfunction, which may be exacerbated by both poorly controlled postoperative pain and commonly used pain medications. This narrative review summarizes the literature published in the past 10 years for several nonopioid analgesics commonly prescribed to the geriatric patient in the perioperative period. Nonopioid analgesics are broken down as follows: medications prescribed throughout the perioperative period (acetaminophen and nonsteroidal anti-inflammatory drugs), medications limited to the acute perioperative setting (N-methyl-D-aspartate receptor antagonists, dexmedetomidine, dexamethasone, and local anesthetics), and medications to be used with caution in the geriatric patient population (gabapentinoids and muscle relaxants). Our search identified 1757 citations, but only 33 specifically focused on geriatric analgesia. Of these, only 21 were randomized clinical trials' and 1 was a systematic review. While guidance in tailoring pain regimens that focus on the use of nonopioid medications in the geriatric patient is lacking, we summarize the current literature and highlight that some nonopioid medications may extend benefits to the geriatric patient beyond analgesia.

Immune Modulatory Effects of Nonsteroidal Anti-inflammatory Drugs in the Perioperative Period and Their Consequence on Postoperative Outcome

Nonsteroidal anti-inflammatory drugs are among the most commonly administered drugs in the perioperative period due to their prominent role in pain management. However, they potentially have perioperative consequences due to immune-modulating effects through the inhibition of prostanoid synthesis, thereby affecting the levels of various cytokines. These effects may have a direct impact on the postoperative outcome of patients since the immune system aims to restore homeostasis and plays an indispensable role in regeneration and repair. By affecting the immune response, consequences can be expected on various organ systems. This narrative review aims to highlight these potential immune system-related consequences, which include systemic inflammatory response syndrome, acute respiratory distress syndrome, immediate and persistent postoperative pain, effects on oncological and neurologic outcome, and wound, anastomotic, and bone healing.

Neuroinflammation in perioperative neurocognitive disorders: From bench to the bedside

The perioperative neurocognitive disorders (PNDs) are one of the most common complications in elderly patients characterized by various forms of cognitive decline after anesthesia and surgery. Although the etiology for PNDs remained unclear, neuroinflammation has been characterized as one of the major causes, especially in the elderly patients. The activation of glial cells including microglia and astrocytes plays a significant role in the inflammatory responses in central nerve system (CNS). Although carefully designed, clinical studies on PNDs showed controversial results. Meanwhile, preclinical studies provided evidence from various levels, including behavior performance, protein levels, and gene expression. In this review, we summarize high‐quality studies and recent advances from both clinical and preclinical studies and provide a broad view from the onset of PNDs to its potential therapeutic targets. Future studies are needed to investigate the signaling pathways in PNDs for prevention and treatment, as well as the relationship of PNDs and future neurocognitive dysfunction.

Transcutaneous electrical acupoint stimulation for postoperative cognitive dysfunction in geriatric patients with gastrointestinal tumor: a randomized controlled trial

Background

This study aimed to evaluate the effect of perioperative transcutaneous electrical acupoint stimulation (TEAS) on postoperative cognitive dysfunction (POCD) in older patients who were diagnosed with gastrointestinal tumor and received radical resection of gastrointestinal tumors under general anesthesia.

Methods

A total of 68 patients who received radical resection of gastrointestinal tumors under general anesthesia were randomly divided into two groups. TEAS group patients received TEAS treatment. The treatment time was 30 min before the induction of anesthesia until the end of the surgery, 1 day before operation and from the first day to the third day after the operation. Except on the day of surgery, we treated the patients for 30 min once a day. In the sham TEAS group, the electronic stimulation was not applied and the treatment was the same as the TEAS group. The primary outcome was perioperative cognition evaluated by the Mini-Mental State Examination (MMSE) and secondary outcomes were the perioperative level of interleukin-6 (IL-6), S100 calcium-binding protein β (S100β), and C-reactive protein (CRP).

Results

The postoperative score of MMSE, orientation, memory, and short-term recall in the sham TEAS group was significantly lower than the preoperative and TEAS group (P < 0.05). The incidence of POCD in the TEAS group (21.88%) was lower than those in the sham TEAS group (40.63%). S100β, IL-6, and CRP in the TEAS group were significantly lower than those in the sham TEAS group on the third day after the operation (P< 0.05). Postoperative S100β, IL-6, and CRP in two groups were significantly higher than those before operation except for S100β on the third day after the operation in the TEAS group (P < 0.05).

Conclusions

Perioperative TEAS treatment reduced the postoperative inflammatory response and increased the postoperative cognitive function score and decrease the incidence of POCD in geriatric patients with gastrointestinal tumor.

Trial registration

ClinicalTrials.gov NCT04606888. Registered on 27 October 2020. https://register.clinicaltrials.gov.

Update on the Mechanism and Treatment of Sevoflurane-Induced Postoperative Cognitive Dysfunction

Sevoflurane is one of the most widely used anesthetics for the induction and maintenance of general anesthesia in surgical patients. Sevoflurane treatment may increase the incidence of postoperative cognitive dysfunction (POCD), and patients with POCD exhibit lower cognitive abilities than before the operation. POCD affects the lives of patients and places an additional burden on patients and their families. Understanding the mechanism of sevoflurane-induced POCD may improve prevention and treatment of POCD. In this paper, we review the diagnosis of POCD, introduce animal models of POCD in clinical research, analyze the possible mechanisms of sevoflurane-induced POCD, and summarize advances in treatment for this condition.

Dexmedetomidine Mitigated NLRP3-Mediated Neuroinflammation via the Ubiquitin-Autophagy Pathway to Improve Perioperative Neurocognitive Disorder in Mice

Background: Surgery and anesthesia-induced perioperative neurocognitive disorder (PND) are closely related to NOD-like receptors (NLR) family, pyrin domain containing 3 (NLRP3) inflammasome microglia inflammatory response. Inhibiting the occurrence of neuroinflammation is an important treatment method to improve postoperative delirium. Fewer NLRP3-targeting molecules are currently available in the clinic to reduce the incidence of postoperative delirium. Dexmedetomidine (DEX), an α2 adrenergic receptor agonist has been shown to have antioxidant and anti-inflammatory activities. The present study showed that DEX reduced the production of cleaved caspase1 (CASP1) and destroyed the NLRP3–PYD And CARD Domain Containing (PYCARD)–CASP1 complex assembly, thereby reducing the secretion of IL-1β interleukin beta (IL-1β). DEX promoted the autophagy process of microglia and reduced NLRP3 expression. More interestingly, it promoted the ubiquitination and degradation of NLRP3. Thus, this study demonstrated that DEX reduced NLRP3-mediated inflammation through the activation of the ubiquitin-autophagy pathway. This study provided a new mechanism for treating PND using DEX.

Methods: C57BL/6 mice were pre-administered DEX 3 days in advance, and an abdominal exploration model was used to establish a perioperative neurocognitive disorder model. The anti-inflammatory effect of DEX was explored in vivo by detecting NLRP3-CASP1/IL-1β protein expression and behavioral testing. Primary microglia were stimulated with lipopolysaccharide (LPS) and adenosine triphosphate (ATP) in vitro, the expression of CASP1 and IL-1β was detected in the supernatant of cells, and the expression of autophagy-related proteins microtubule-associated protein 1 light chain 3 beta (MAP1LC3B) and sequestosome 1 (SQSTM1) was examined in the cytoplasm. Meanwhile, Co-immunoprecipitation (Co-IP) was used to detect NLRP3 protein ubiquitination so as to clarify the new mechanism underlying the anti-inflammatory effect of DEX.

Results: Pre-administration of DEX reduced the protein expression of NLRP3, CASP1, and IL-1β in the hippocampus of mice induced by surgery and also improved the impairment of learning and memory ability. At the same time, DEX also effectively relieved the decrease in spine density of the hippocampal brain induced by surgery. DEX decreased the cleaved CASP1 expression, blocked the assembly of NLRP3–PYCARD–CASP1 complex, and also reduced the secretion of mature IL-1β in vitro. Mechanically, it accelerated the degradation of NLRP3 inflammasome via the autophagy–ubiquitin pathway and reduced the green fluorescent protein/red fluorescent protein MAP1LC3B ratio, which was comparable to the effect when using the autophagy activator rapamycin (Rapa). Furthermore, it increased the ubiquitination of NLRP3 after LPS plus ATP stimulated microglia.

Conclusion: DEX attenuated the hippocampal brain inflammation by promoting NLRP3 inflammasome degradation via the autophagy–ubiquitin pathway, thus improving cognitive impairment in mice.

[Correlation of cerebrospinal fluid amyloid β-protein 42 and neurofilament light protein levels with postoperative neurocognitive dysfunction in elderly patients]

OBJECTIVE

To detect cerebrospinal fluid levels of amyloid beta- protein 42 (Aβ42) and neurofilament light protein (NFL) and explore their correlation with postoperative neurocognitive dysfunction (PNCD) in elderly patients.

OBJECTIVE

A total of 90 elderly patients undergoing hip or knee replacement with joint epidural anesthesia in our Hospital between January, 2017 and December, 2018 were recruited in this study. The levels of Aβ42 and NFL in the cerebrospinal fluid were detected using ELISA. Simple cognitive status assessment scale (MMSE) was used to evaluate the cognitive status of the patients 1 day before and 7 days after the surgery. All the patients underwent neurocognitive function tests, and the z-score method was used to determine the occurrence of PNCD. Spearman rank correlation analysis was used to analyze the correlation of Aβ42 and NFL levels in the cerebrospinal fluid with MMSE scores. Receiver operating characteristic curve (ROC) was used to analyze the predictive value of cerebrospinal fluid Aβ42 and NFL levels for PNCD.

OBJECTIVE

PNCD occurred in 38 of the 90 elderly patients, with an incidence of 42.2%. The level of Aβ42 in the cerebrospinal fluid was significantly lower in PNCD group than in the nonPNCD group (1.96 vs 2.54 ng/mL; t=3.29, P < 0.05); the concentration of NFL in the cerebrospinal fluid was significantly higher in PNCD group than in non- PNCD group (4.59 vs 3.16 ng/mL; t=3.72, P < 0.05). Aβ42 level in the cerebrospinal fluid was positively correlated while NFL was negatively correlated with the MMSE score of the patients (r=-0.659, P < 0.05; r=-0.626, P < 0.05). ROC curve analysis showed that the area under the curve (AUC) of cerebrospinal fluid Aβ42 and NFL levels were 0.744 and 0.768, respectively; the AUC of their combination was 0.847 for prediction of PNCD.

OBJECTIVE

Elderly patients with PNCD have significantly higher levels of Aβ42 and NFL in the cerebrospinal fluid than those without PNCD. Both Aβ42 and NFL levels in the cerebrospinal fluid can help to predict the occurrence of POCD in elderly patients, and their combination has a higher diagnostic value.