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.

Effect of intranasal insulin on perioperative cognitive function in older adults: a randomized, placebo-controlled, double-blind clinical trial.

BACKGROUND: Postoperative cognitive impairment are common neural complications in older surgical patients and exacerbate the burden of medical care on families and society. METHODS: A total of 140 older patients who were scheduled for elective orthopaedic surgery or pancreatic surgery with general anaesthesia were randomly assigned to Group S or Group I with a 1:1 allocation. Patients in Group S and Group I received intranasal administration of 400 µL of normal saline or 40 IU/400 µL of insulin, respectively, once daily from 5 minutes before anaesthesia induction until 3 days postoperatively. Perioperative cognitive function was assessed using the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment-Basic (MoCA-B) at 1 day before and 3 days after surgery and postoperative delirium (POD) incidence was assessed using the 3-minute Diagnostic Interview for CAM (3D-CAM) on postoperative days 1-3. Serum levels of interleukin-6 (IL-6), tumour necrosis factor α (TNF-α), S100-ß and C-reactive protein (CRP) were measured on the first day after surgery. RESULTS: Insulin treatment significantly increased postoperative MMSE and MoCA-B scores in group I than in group S (P < 0.001, P = 0.001, respectively), decreased the incidence of POD within the 3-day postoperative period in Group I than in Group S (10.9% vs 26.6%, P = 0.024), and inhibited postoperative IL-6 and S100-ß levels in Group I compared to Group S (P = 0.034, P = 0.044, respectively). CONCLUSIONS: Intranasal insulin administration is thus suggested as a potential therapy to improve postoperative cognition in older patients undergoing surgery. However, a more standardized multi-centre, large-sample study is needed to further validate these results.

Two-lung ventilation with artificial pneumothorax on cerebral desaturation and early postoperative cognitive outcome: a randomized controlled trial.

BACKGROUND: The effect of two lung ventilation (TLV) with carbon dioxide artificial pneumothorax on cerebral desaturation and postoperative neurocognitive changes in elderly patients undergoing elective minimally invasive esophagectomy (MIE) is unclear. OBJECTIVES: The first aim of this study was to compare the effect of TLV and one lung ventilation (OLV) on cerebral desaturation. The second aim was to assess changes in early postoperative cognitive outcomes of two ventilation methods. METHODS: This prospective, randomized, controlled trial enrolled patients 65 and older scheduled for MIE. Patients were randomly assigned (1:1) to TLV group or OLV group. The primary outcome was the incidence of cerebral desaturation events (CDE). Secondary outcomes were the cumulative area under the curve of desaturation for decreases in regional cerebral oxygen saturation (rSO2) values below 20% relative to the baseline value (AUC.20) and the incidence of delayed neurocognitive recovery. RESULTS: Fifty-six patients were recruited between November 2019 and August 2020. TLV group had a lower incidence of CDE than OLV group [3 (10.71%) vs. 13 (48.14%), P = 0.002]. TLV group had a lower AUC.20 [0 (0-35.86) % min vs. 0 (0-0) % min, P = 0.007], and the incidence of delayed neurocognitive recovery [2 (7.4%) vs. 11 (40.7%), P = 0.009] than OLV group. Predictors of delayed neurocognitive recovery on postoperative day 7 were age (OR 1.676, 95% CI 1.122 to 2.505, P = 0.006) and AUC.20 (OR 1.059, 95% CI 1.025 to 1.094, P < 0.001). CONCLUSION: Compared to OLV, TLV had a lower incidence of CDE and delayed neurocognitive recovery in elderly patients undergoing MIE. The method of TLV combined with carbon dioxide artificial pneumothorax may be an option for these elderly patients. Chinese Clinical Trial Registry (identifier: ChiCTR1900027454).

Value of narcotrend anesthesia depth monitoring in predicting POCD in gastrointestinal tumor anesthesia block patients.

BACKGROUND: The purpose of this research was to evaluate the efficacy of Narcotrend (NT) monitoring on cognitive dysfunction in patients undergoing anesthesia blockade for gastrointestinal tumors and its effect on cerebral oxygen metabolism and inflammatory response. METHODS: Patients preparing to undergo resection of gastrointestinal tumor resection were included and randomly divided into a control group (depth of anesthesia assessed by physician experience) and a research group (depth of anesthesia monitored by NT). HR and MAP were monitored at the preoperatively (T0), 12 h postoperative (T1), 24 h postoperative (T2), and 48 h postoperative (T3) stages. MMSE score was recorded to assess changes in cognitive function. Intracerebral oxygenation indicators (CjvO2, CERO2, and rSO2) were assessed by a blood gas analyzer. ELISA assay was conducted to explore the serum inflammatory indexes (CRP, IL-1ß, and TNF-α) and neurological function indicators (NSE and MBP). RESULTS: MAP was higher in the research group than in the control group at T1 and T2 (P < 0.05). MMSE scores at T1, T2, and T3 stages were higher in the research group than in the control (P < 0.05). The incidence of POCD was also lower in the research group compared with the control (P < 0.05). CjvO2, CERO2, and rSO2 were significantly higher (P < 0.05) and were positively correlated with the MMSE scores. Postoperative serum inflammatory indexes were significantly elevated in both groups, but more significantly in the control group (P < 0.05). Both neurological function indicators were usually reduced after surgery, but the reduction was more significant in the research group (P < 0.05). CONCLUSION: NT monitoring of anesthetic depth has a less physical impact on patients with gastrointestinal tumor anesthetic block, reduces the degree of postoperative POCD, and has significant clinical value.

The use of peripheral nerve block decrease incidence of postoperative cognitive dysfunction following orthopedic surgery: A systematic review and meta-analysis.

BACKGROUND: Postoperative neurocognitive disorders (PNDs) frequently occur following orthopedic surgery and are closely associated with adverse prognosis. PNDs are an emerging concept that includes both postoperative cognitive dysfunction (POCD) and postoperative delirium (POD). The prevention of combined use of peripheral nerve block (PNB) and general anesthesia (GA) on POCD and/or POD incidence following orthopedic surgery remains unknown. We aimed to investigate the effect of this combined anesthesia method on POCD/POD incidence after orthopedic surgery, compared with GA. METHODS: The databases of PubMed, Web of Science, Embase via Ovid, and the Cochrane Central Register of Controlled Trials were searched for all available randomized controlled trials (RCTs). The incidence of POD/POCD was the primary outcome. Continuous and dichotomous outcomes are represented as standardized mean differences [SMD, 95% confidence interval (CI)] and risk ratios [RR, 95%CI], respectively. RESULTS: Meta-analysis of twelve RCTs with a total of 1488 patients revealed that compared with GA, PNB plus GA decreased the incidence of POCD (RR: 0.58, 95%CI: 0.35 to 0.95, P = 0.03, I2 = 0%), while the incidence of POD had no significant difference (RR: 0.87, 95%CI: 0.54 to 1.40, P = 0.57, I2 = 67%). Compared with GA alone, a significant decrease of intraoperative and postoperative opioid consumption (SMD: -1.54, 95%CI: -2.26 to -0.82, P < 0.0001, I2 = 89%; SMD: -7.00, 95%CI: -9.89 to -4.11, P < 0.00001, I2 = 99%) and postoperative nausea and vomiting incidence (RR: 0.16, 95%CI: 0.06 to 0.44, P = 0.0004, I2 = 0%) was found with PNB plus GA. CONCLUSIONS: The combined use of PNB and GA decreases the incidence of POCD but not POD following orthopedic surgery. TRIAL REGISTRATION: The protocol of this study was registered with PROSPERO (Registration Number: CRD42022366454).

The role of dexmedetomidine administered via intravenous infusion as adjunctive therapy to mitigate postoperative delirium and postoperative cognitive dysfunction in elderly patients undergoing regional anesthesia: a meta-analysis of randomized controlled trials.

STUDY OBJECTIVE: This meta-analysis aimed to assess whether continuous intravenous administration of DEX during surgery can be part of the measures to prevent the onset of postoperative delirium and postoperative cognitive dysfunction in elderly individuals following regional anesthesia. METHODS: We searched the databases of PubMed, Embase, the Cochrane Library and China National Knowledge Infrastructure (by June 1, 2023) for all available randomized controlled trials assessing whether intravenous application of dexmedetomidine can help with postoperative delirium and postoperative cognitive dysfunction in the elderly with regional anesthesia. Subsequently, we carried out statistical analysis and graphing using Review Manager software (RevMan version 5.4.1) and STATA software (Version 12.0). MAIN RESULTS: Within the scope of this meta-analysis, a total of 18 randomized controlled trials were included. Among them, 10 trials aimed to assess the incidence of postoperative delirium as the primary outcome, while the primary focus of the other 8 trials was on the incidence of postoperative cognitive dysfunction. The collective evidence from these 10 studies consistently supports a positive relationship between the intravenous administration of dexmedetomidine and a decreased risk of postoperative delirium (RR: 0.48; 95%CI: 0.37 to 0.63, p < 0.00001, I2 = 0%). The 8 literature articles and experiments evaluating postoperative cognitive dysfunction showed that continuous intravenous infusion of dexmedetomidine during the entire surgical procedure exhibited a positive preventive effect on cognitive dysfunction among the elderly population with no obvious heterogeneity (RR: 0.35; 95%CI: 0.25 to 0.49,p < 0.00001, I2 = 0%). CONCLUSION: Administering dexmedetomidine intravenously during surgery can potentially play a significant role in preventing postoperative delirium and postoperative cognitive dysfunction in patients older than 60 years with regional anesthesia according to this meta-analysis.

The influence of dexmedetomidine added to ropivacaine for transversus abdominis plane block on perioperative neurocognitive disorders after radical colorectal cancer surgery: randomized, double-blind, controlled trial.

OBJECTIVE: Perioperative Neurocognitive Disorders (PND) is a common neurological complication after radical colorectal cancer surgery, which increases adverse outcomes. So, our objective is to explore the influence of dexmedetomidine added to ropivacaine for transversus abdominis plane block (TAPB) on perioperative neurocognitive disorders, and to provide a new way to reduce the incidence of PND. METHODS: One hundred and eighty patients submitted to radical laparoscopic colorectal cancer surgery were randomly divided into Control group and Dex group. Ultrasound guided TAPB was performed after anesthesia induction: 0.5% ropivacaine 20 ml was injected into each transversus abdominis plane in Control group, 0.5% ropivacaine + 1 µg/kg dexmedetomidine (amounting to 20 ml) in Dex group. We observed the incidence of PND within 30 days after surgery. RESULTS: One hundred and sixty-nine cases were finally analyzed, including 84 cases in Control group and 85 cases in Dex group. Compared with Control group, there was no significant difference in terms of the incidence of PND on the 3rd day and the 7th day (P > 0.05), but the incidence significantly decreased at the 6th hour, at the 24th hour and on the 30th day after surgery (P < 0.05) in Dex group. CONCLUSION: Dexmedetomidine added to ropivacaine for TAPB can reduce the incidence of PND in the first 24 h after surgery and on the 30th postoperative day, which may be related to reduce the consumption of general anesthetics and provide satisfactory postoperative analgesia. TRIAL REGISTRATION: 29 /05/ 2021, ChiCTR2100046876.

Cognitive Training to Reduce Memory Disturbance Associated With Postoperative Cognitive Impairment After Elective Noncardiac Surgery: An Experimental Study.

PURPOSE: Assess the efficiency of a cognitive training program using an artificial intelligence application to optimize cognitive reserve and reduce memory disturbance in patients aged 55 to 75 after Class II-III elective noncardiac surgery. DESIGN: Experimental with random assignment. METHODS: The study was conducted on 80 patients undergoing surgery at the Teknon Medical Center Hospital in Barcelona, from April 2018 to June 2021. Both groups were evaluated with cognitive tests before surgery and 7 and 30 days after surgery. The experimental group was subjected to cognitive training for 10 days before surgery to improve their cognitive reserve. FINDINGS: Significant differences were found between the study groups 30 days after surgery in the three screening tests (Mini-Cog, T@M, and MFE). The intervention group presented with fewer cognitive and memory alterations. Age and pre-existing comorbidities were not correlated with an impact on memory impairment or cognitive function. CONCLUSIONS: A cognitive training program based on artificial intelligence, prescribed and monitored by anesthesia nurses has a positive impact on increasing cognitive reserve and reducing memory disturbance in patients aged 55 to 75 undergoing Class II to III elective, noncardiac surgery. This intervention may serve as a prehabilitation strategy in patients with a risk of cognitive dysfunction evaluated by anesthesia nurses for the purpose of preserving their cognitive function and optimizing their recovery.

Exploring the Potential Role of Dexmedetomidine in Reducing Postoperative Cognitive Dysfunction in Elderly Hip Fracture Patients.

BACKGROUND: Hip fractures are prevalent in the elderly; however, Postoperative Cognitive Dysfunction (POCD) is a possible complication of hip fracture surgery in elderly patients. This study examines the influence and the underlying mechanism of dexmedetomidine on POCD in elderly patients following hip fracture surgery. METHODS: The retrospective study involved elderly patients with hip fracture who were treated at the Fifth Affiliated Hospital of Xinjiang Medical University from October 2021 to August 2022. During the surgery procedures, dexmedetomidine was administrated and the peripheral blood samples were collected from the patients. Inflammatory factors were measured using Enzyme-linked immunosorbent assay (ELISA), while pyroptosis-related proteins were detected through quantitative reverse transcription PCR (RT-qPCR) and western blot. Additionally, the levels of CD4+T and CD8+T cells were assessed using flow cytometry. An aged rats hip fracture model was established to further investigate the impact of dexmedetomidine on postoperative mobility, cognition function, pyroptosis and immune cells in rats. RESULTS: Postoperative cognitive function in patients did not show significant alteration when compared with pre-operation levels (p > 0.05). There were notable reduction in the levels of interleukin-18 (IL-18), Caspase-3, Gasdermin-D (GSDMD) and NLR Family Pyrin Domain Containing 3 (NLRP3) (p < 0.001), accompanied by an increase in the proportion of CD4+T cells and an decrease in CD8+T cells after operation (p < 0.01). In aged rats, postoperative exploratory activities increased compared to their preoperative state. Compared with preoperative levels, the levels of interleukin-1ß (IL-1ß), IL-18, Caspase-3, GSDMD, and NLRP3 were significantly decreased (p < 0.001), the proportion of CD4+T cells was increased, and the proportion of CD8+T cells was decreased postoperatively (p < 0.01). CONCLUSIONS: Although there was no significant alteration in postoperative cognitive function in patients, dexmedetomidine may still play a role in mitigating POCD potentially due to its effects on reducing immune inflammation and pyroptosis markers. Further research is needed to fully understand the underlying mechanisms and its clinical implications.

taVNS Alleviates Sevoflurane-Induced Cognitive Dysfunction in Aged Rats Via Activating Basal Forebrain Cholinergic Neurons.

Postoperative cognitive dysfunction (POCD) is a common complication of central nervous system after anesthesia or surgery. Sevoflurane, an inhalation anesthetic, may inhibit cholinergic pathway that induce neuronal death and neuroinflammation, ultimately leading to POCD. Transauricular vagus nerve stimulation (taVNS) has neuroprotective effects in POCD rats, but the mechanisms related to cholinergic system have not been revealed. Sprague-Dawley rats were anesthetized with sevoflurane to construct the POCD model. The immunotoxin 192-IgG-saporin (192-sap) selectively lesioned cholinergic neurons in the basal forebrain, which is the major source of cholinergic projections to hippocampus. After lesion, rats received 5 days of taVNS treatment (30 min per day) starting 24 h before anesthesia. Open field test and Morris water maze were used to test the cognitive function. In this study, rats exposed to sevoflurane exhibited cognitive impairment that was attenuated by taVNS. In addition, taVNS treatment activated cholinergic system in the basal forebrain and hippocampus, and downregulated the expression of apoptosis- and necroptosis-related proteins, such as cleaved Caspase-3 and p-MLKL, in the hippocampus. Meanwhile, the activation of Iba1+ microglial by sevoflurane was reduced by taVNS. 192-sap blocked the cholinergic system activation in the basal forebrain and hippocampus and inhibited taVNS-mediated neuroprotection and anti-inflammation effects in the hippocampus. Generally, our study indicated that taVNS might alleviate sevoflurane-induced hippocampal neuronal apoptosis, necroptosis and microglial activation though activating cholinergic system in the basal forebrain.

Prevention of Postoperative Cognitive Dysfunction by Minocycline in Elderly Patients after Total Knee Arthroplasty: A Randomized, Double-blind, Placebo-controlled Clinical Trial.

BACKGROUND: There are no effective pharmacologic interventions for preventing postoperative cognitive dysfunction in daily practice. Since the antibiotic minocycline is known to suppress postoperative neuroinflammation, this study hypothesized and investigated whether minocycline might have a preventive effect on postoperative cognitive dysfunction after noncardiac surgery. METHODS: This study included patients aged more than 60 yr undergoing total knee arthroplasty under general anesthesia. They were randomly assigned to minocycline and placebo groups, to orally receive 100 mg of minocycline or placebo twice daily from the day before surgery until the seventh day after surgery. Cognitive function was evaluated before surgery, and 1 week and 3 months after surgery, using a battery of four cognitive function tests, including Visual Verbal Learning Test, Trail Making Test, Stroop Color and Word Test, and Letter-Digit Coding Task. Additionally, 30 healthy volunteers were subjected to the same tests as the patients to examine the learning effect of repeated tests. The occurrence of postoperative cognitive dysfunction was judged from the results of the neurocognitive test battery, with consideration of the learning effect. The secondary endpoints were the effects of minocycline on postoperative delirium and postoperative pain. RESULTS: A total of 100 patients were randomized to the minocycline group, and 102 were randomized to the placebo group. The average age of patients was 75 yr. Evaluation showed no significant difference in the incidence of postoperative cognitive dysfunction between the minocycline and placebo groups at both 1 week (8 of 90 [8.9%] vs. 4 of 95 [4.2%]; odds ratio, 2.22 [95% CI, 0.64 to 7.65]; P = 0.240) and 3 months (15.3 of 90 [17.0%] vs. 15.3 of 95 [16.1%]; odds ratio, 1.07 [95% CI, 0.49 to 2.32]; P = 0.889) postoperatively. Missing data 3 months after surgery were corrected by the multiple imputation method. There were no differences between the two groups in postoperative delirium and postoperative pain. CONCLUSIONS: Minocycline is likely to have no preventive effect on postoperative cognitive dysfunction.

Effects of regional cerebral oxygen saturation monitoring on postoperative cognitive dysfunction in older patients: a systematic review and meta-analysis.

BACKGROUND: Postoperative cognitive dysfunction (POCD) is common after surgery and anesthesia, particularly in older patients. It has been reported that regional cerebral oxygen saturation (rSO2) monitoring potentially influences the occurrence of POCD. However, its role in the prevention of POCD remains controversial in older patients. Additionally, the quality of evidence on this topic is still relatively poor. METHODS: The electronic databases PubMed, EMBASE, Web of Science, and Cochrane Library were systematically searched using the indicated keywords from their inception to June 10, 2022. We limited our meta-analysis to randomized controlled trials (RCTs) that assessed the effects of rSO2 monitoring on POCD in older patients. Methodological quality and risk of bias were assessed. The primary outcome was the incidence of POCD during hospitalization. The secondary outcomes were postoperative complications and the length of hospital stay (LOS). Odds ratios (OR) and 95% confidence intervals (CI) were calculated to determine the incidence of POCD and postoperative complications. The standardized mean difference (SMD) instead of the raw mean difference and 95% CI were calculated for LOS. RESULTS: Six RCTs, involving 377 older patients, were included in this meta-analysis. The incidence of POCD ranges from 17 to 89%, with an overall prevalence of 47% in our pooled analysis. Our results demonstrated that rSO2-guided intervention could reduce the incidence of POCD in older patients undergoing non-cardiac surgery (OR, 0.44; 95% CI, 0.25 to 0.79; P = 0.006) rather than cardiac surgery (OR, 0.69; 95% CI, 0.32 to 1.52; P = 0.36). Intraoperative rSO2 monitoring was also associated with a significantly shorter LOS in older patients undergoing non-cardiac surgery (SMD, -0.93; 95% CI, -1.75 to -0.11; P = 0.03). Neither the incidence of postoperative cardiovascular (OR, 1.12; 95% CI, 0.40 to 3.17; P = 0.83) nor surgical (OR, 0.78; 95% CI, 0.35 to 1.75; P = 0.54) complications were affected by the use of rSO2 monitoring. CONCLUSION: The use of rSO2 monitoring is associated with a lower risk of POCD and a shorter LOS in older patients undergoing non-cardiac surgery. This may have the potential to prevent POCD in high-risk populations. Further large RCTs are still warranted to support these preliminary findings.

Effects of anterior approach to quadratus lumborum block on postoperative cognitive function following hip surgery in older people: a randomized controlled clinical trial.

BACKGROUND: Peripheral nerve block, including the quadratus lumborum block (QLB), has been used for postoperative analgesia in hip surgery. However, the effects of QLB on cognitive function after hip surgery remain unknown. This study aimed to assess the effects of the anterior approach to QLB on postoperative cognitive function in older people undergoing hip surgery. METHODS: Sixty older people who underwent hip surgery from May 2021 to May 2022 were randomly divided into the QLB (n = 30) and control groups (n = 30). The Montreal Cognitive Assessment (MoCA) score (mean ± SD) was measured one day preoperatively and seven and 30 days postoperatively. The frequency (%) of postoperative cognitive dysfunction (POCD) was examined seven and 30 days postoperatively. The visual analog scale (VAS) scores at rest and Bruggrmann comfort scale (BCS) scores [Median (IQR)] 6 h (t1), 12 h (t2), 24 h (t3), and 48 h (t4) after surgery were assessed. The plasma high mobility group box protein 1 (HMGB1) and levels of interleukin-6 (IL-6) (mean ± SD) were evaluated 1 h preoperatively (baseline) and 24 h postoperatively (day 1). The requirement for rescue analgesia [Median (IQR)], time to first off-bed activity (mean ± SD), and adverse effects after surgery were also recorded. RESULTS: Compared with the control group, the frequency of POCD was significantly lower in the QLB group seven days postoperatively (10.7% vs. 34.5%, P = 0.033), but no difference at 30 days postoperatively (3.6% vs. 10.3%, P = 0.319). There was no significant difference in MoCA scores between the two groups at one day preoperatively and 30 days postoperatively. However, the MoCA scores at seven days postoperatively were higher in the QLB group than in the control group (27.4 ± 1.81 vs. 26.4 ± 1.83, P = 0.043). In the QLB group, the VAS scores at t1, t2, and t3 were lower [3(2-4) vs. 4(3-4), P = 0.028; 3(2-3) vs. 4(3-5), P = 0.009; 2(1-3) vs. 2(2-3), P = 0.025], and the BCS scores at t1, t2, and t3 were higher than those in the control group [3(1-3) vs. 1(1-2), P = 0.006; 3(2-3) vs. 2(1-3), P = 0.011; 3(2-4) vs. 2(2-3), P = 0.041]. The patients in the QLB group reported significantly fewer requirements for rescue analgesia [0(0-1) vs. 1(0-2), P = 0.014]. The plasma levels of HMGB1 and IL-6 at 24 h postoperatively in the QLB group were significantly lower than in the control group (749.0 ± 185.7 vs. 842.1 ± 157.9, P = 0.046; 24.8 ± 8.1 vs. 31.9 ± 5.5, P < 0.001). The time to first off-bed activity from the end of surgery was shorter in the QLB group (25.3 ± 5.3 vs. 29.7 ± 6.9, P = 0.009). There was no significant difference in the incidence of postoperative complications between the two groups. CONCLUSIONS: Anterior QLB given to older people undergoing hip surgery could promote early postoperative cognitive function recovery, provide adequate postoperative analgesia, and inhibit the release of inflammatory factors. TRIAL REGISTRATION: Chictr.org.cn identifier ChiCTR2000040724 (Date of registry: 08/12/2020, prospectively registered).

Metformin Ameliorates Postoperative Cognitive Dysfunction through Regulation of the AMPK/SIRT1 Pathway.

BACKGROUND: Postoperative cognitive dysfunction (POCD) is a common postoperative complication in elderly patients. The purpose of this study was to investigate the mechanism through which metformin improves postoperative cognitive function. METHODS: In the in vivo experiment, 18-month-old Sprague-Dawley (SD) rats were randomly divided into four groups (n = 12 in each group): the control, metformin, operation, and operation plus metformin groups. The animals were pretreated with metformin by gavage once daily for two weeks. The Morris water maze (MWM) was used to measure cognitive ability. In the in vitro experiment, BV2 cells were divided into five groups: the control, metformin, lipopolysaccharide (LPS), LPS plus metformin, and LPS plus metformin plus compound C groups. We stimulated microglia with LPS (500 ng/mL). Immunofluorescence and Western blotting were used to assess ROS (reactive oxygen species) levels, autophagy-associated protein levels and adenosine monophosphate-activated protein kinase (AMPK)/regulator factor 2-related enzyme 1 (SIRT1) signaling pathway activity in the rat cortex and microglial cells. RESULTS: In the MWM test, the metformin-pretreated rats spent a higher proportion of time in the target quadrant. Immunofluorescence showed that the fluorescence intensity of LC3 in the cortex was increased in rats pretreated with metformin. Western blotting indicated that metformin upregulated the expression of autophagy-related and AMPK/SIRT1 signaling pathway-related proteins in the cortex after surgery. By activating the AMPK/SIRT1 signaling pathway in vitro, metformin reduced microglial activation and oxidative stress and promoted autophagy. CONCLUSIONS: Through the AMPK/SIRT1 pathway, metformin can boost autophagy and reduce oxidative stress in cortical microglia in older rats, in turn improving postoperative cognitive function.

Targeted temperature management in cardiac surgery: a systematic review and meta-analysis on postoperative cognitive outcomes.

BACKGROUND: Postoperative cognitive decline occurs commonly after cardiac surgery. The available literature is inconclusive on the role of intraoperative causal or protective factors. METHODS: We systematically reviewed studies evaluating delayed neurocognitive recovery (DNR), postoperative neurocognitive disorder (NCD), stroke, and the mortality rates among patients undergoing hypothermic or normothermic cardiopulmonary bypass (CPB). We further performed a subgroup analysis for age, surgery type (coronary artery bypass grafting [CABG], valve surgery, or combined), and the mean arterial blood pressure (MAP) during CPB, and conducted a proportion meta-analysis after calculation of single proportions and confidence intervals (CIs). RESULTS: We included a total of 58 studies with 9609 patients in our analysis. Among these, 1906 of 4010 patients (47.5%) had DNR, and 2071 of 7160 (28.9%) had postoperative NCD. Ninety of 4625 patients (2.0%) had a stroke, and 174 of 7589 (2.3%) died. There was no statistically significant relationship between the considered variables and DNR, NCD, stroke, and mortality. In the subgroup analysis comparing hypothermic with normothermic CPB, we found higher NCD rates after combined surgery; for normothermic CPB cases only, the rates of DNR and NCD were lower after combined surgery compared with CABG surgery. A MAP >70 mm Hg compared with MAP=50-70 mm Hg during CPB was associated with a lower rate of DNR. CONCLUSIONS: Temperature, MAP during cardiopulmonary bypass age, and surgery type were not associated with neurocognitive disorders, stroke, and mortality in cardiac surgery. Normothermic cardiopulmonary bypass, particularly when performed with MAP >70 mm Hg, may reduce the risk of postoperative neurocognitive decline after cardiac surgery. PROSPERO REGISTRATION NUMBER: CRD42019140844.

A Review of the Biological Mechanisms of Dexmedetomidine for Postoperative Neurocognitive Disorders.

Postoperative neurocognitive disorders are common neurological complications following surgery that are generally characterized by varying degrees of cognitive impairment. Postoperative neurocognitive disorders can exhibit as short-term postoperative delirium and/or long-term postoperative cognitive dysfunction. In addition, postoperative neurocognitive disorders may result in poor outcomes in patients, and are a leading cause of postoperative morbidity and mortality, particularly in elderly patients. Recently, there has been a heightened interest in mechanisms and clinical treatments for postoperative neurocognitive disorders. Though some influencing factors and mechanisms of postoperative neurocognitive disorders have been revealed, they remain troublesome problems in clinical departments. Dexmedetomidine is a commonly used anesthetic adjuvant that may help improve postoperative cognitive impairment, especially the conditions of a postoperative acute event (postoperative delirium, within 1 week after operation) and delayed neurocognitive recovery (postoperative cognitive dysfunction, up to 30 days). In the recent literature, dexmedetomidine has been shown to exert positive effects on cognitive impairment in clinical and animal studies, especially for postoperative neurocognitive disorders. However, not all clinical findings support this efficacy. Though some mechanisms of dexmedetomidine on postoperative neurocognitive disorders have been proposed, such as signaling pathways associated with inflammation and apoptosis, this evidence is fragmentary and disputed in the literature. Therefore, this article aims to review the potential biological mechanisms underlying dexmedetomidine's effects on postoperative neurocognitive disorders, providing a reference for future studies.

Ginkgolide B improved postoperative cognitive dysfunction by inhibiting microgliosis-mediated neuroinflammation in the hippocampus of mice.

BACKGROUND: Postoperative cognitive dysfunction (POCD) are a common complication of the central nervous system following surgery and anesthesia. The specific pathogenesis and effective therapeutics of POCD need to be further studied. Ginkgolide B (GB), a platelet-activating factor receptor-specific antagonist, has been suggested to have strong anti-inflammatory effects. Here we tested the effects and mechanism of GB on POCD of aged rats. METHODS: Neurobehavioral tests were used to investigate the effect of GB pretreatment on POCD. The hippocampus were harvested to test the expression of proinflammatory cytokines by ELISA. The expression of the microglial marker ionized calcium-binding adaptor molecule-1 (Iba-1) in the hippocampus was evaluated by western blot assay and immunohistochemistry. A Nissl staining experiment was used to detect the neuronal numbers in the hippocampus. RESULTS: Surgery might result in the overexpression of platelet activating factor (PAF) in the plasma and hippocampus and might cause hippocampus-dependent memory impairment. GB pretreatment, inhibited the activation of microglia, reduced the levels of IL-1ß and TNF-α, decreased the loss of neurons after surgery, and prevented POCD in aged rats. CONCLUSION: Our findings suggested that PAF was involved in the development of POCD. Improvement of POCD by PAF antagonist GB was associated with the inhibition of microgliosis-mediated neuroinflammation and neuronal apoptosis in aged rats.

Does propofol definitely improve postoperative cognitive dysfunction?-a review of propofol-related cognitive impairment.

Postoperative cognitive dysfunction (POCD) is a common brain function-related complication after surgery. In addition to old age being an independent risk factor, anesthetics are also important predisposing factors. Among them, propofol is the most commonly used intravenous anesthetic in clinical practice. It has a rapid onset, short half-life, and high recovery quality. Many studies report that propofol can attenuate surgery-induced cognitive impairment, however, some other studies reveal that propofol also induces cognitive dysfunction. Therefore, this review summarizes the effects of propofol on the cognition, and discusses possible related mechanisms, which aims to provide some evidence for the follow-up studies.

Electroacupuncture relieves postoperative cognitive dysfunction in elderly rats via regulating amp-activated protein kinase autophagy signaling.

Postoperative cognitive dysfunction (POCD) is a common complication after surgery in elderly patients. Electroacupuncture (EA) has been reported to relieve POCD in animal models, but the mechanism remains fully elucidated. The objective of this work was to clarify whether EA could alleviate POCD via regulating autophagy. In this study, aged rats were assigned into 4 groups: control, surgery (rats underwent exploratory laparotomy to induce POCD), EA + S (rats received EA pre-stimulation before surgery), and EA + S + Chloroquine (CQ) (rats were intraperitoneally injected with CQ before EA stimulation and then underwent surgery). The cognitive function of rats was assessed by Morris Water Maze (MWM) test after surgery, and autophagy in hippocampal tissues of rats was evaluated by western blotting and transmission electron microscope. Results indicated that the MWM test revealed that rats showed reduced platform crossing and increased total swimming distance after surgery. However, this impaired spatial memory was improved by EA and EA plus CQ pre-treatment. Besides, the surgery caused an increased expression in LC3II, Beclin-1, AMP-activated protein kinase (AMPK), and p-AMPK in hippocampal tissues of rats, while EA and EA plus CQ pre-treatment also reversed this effect. In addition, the surgery-induced increased amount of autophagic vesicles in hippocampal tissues of rats was reduced by EA and EA plus CQ pre-treatment. In conclusion, EA pre-stimulation could effectively attenuate cognitive impairment in aged rats with POCD via inhibiting AMPK signaling-mediated autophagy.

Prevention of dexmedetomidine on postoperative delirium and early postoperative cognitive dysfunction in elderly patients undergoing hepatic lobectomy. / å³ç¾Žæ‰˜å’ªå®šå¯¹è€å¹´æ‚£è€ è‚å¶åˆ‡é™¤æœ¯åŽè°µå¦„å’Œæ—©æœŸæœ¯åŽè®¤çŸ¥åŠŸèƒ½éšœç¢çš„é¢„é˜²æ•ˆæžœ.

OBJECTIVES: Postoperative delirium (POD) and postoperative cognitive dysfunction (POCD) are common operative neurocognitive disorders, which places a heavy burden on patients, families and society. Therefore, it is very important to search for preventive drugs. Previous studies have demonstrated that perioperative use of dexmedetomidine resulted in a decrease the incidence of POD and POCD. But the specific effect of dexmedetomidine on elderly patients undergoing hepatic lobectomy and its potential mechanism are not clear. This study aims to evaluate the efficacy of intraoperative use of dexmedetomidine on preventing POD and POCD in elderly patients undergoing hepatic lobectomy and the influence on the balance between proinflammation and anti-inflammation. METHODS: This trial was designed as a single-center, prospective, randomized, controlled study. One hundred and twenty hospitalized patients from January 2019 to December 2020, aged 60-80 years old with American Society of Anesthesiologists (ASA) II-III and scheduled for hepatic lobectomy, were randomly allocated into 3 groups (n=40) using a random number table: A C group, a Dex1 group, and a Dex2 group. After anesthesia induction, saline in the C group, dexmedetomidine [0.3 µg/(kg·h)] in the Dex1 group, and dexmedetomidine [0.6 µg/(kg·h)] in the Dex2 group were infused until the end of operation. The incidences of hypotension and bradycardia were compared among the 3 groups. Confusion Assessment Method (CAM) for assessing POD and Mini Mental State Examination (MMSE) for evaluating POCD were recorded and venous blood samples were obtained for the determination of neuron specific enolase (NSE), TNF-α, IL-1ß, and IL-10 at the different time below: the time before anesthesia (T0), and the first day (T1), the third day (T2), the fifth day (T3), and the seventh day (T4) after operation. RESULTS: Compared with the C group, the incidences of bradycardia in the Dex1 group or the Dex2 group increased (both P<0.05) and there was no difference in hypotension in the Dex1 group or the Dex2 group (both P>0.05). The incidences of POD in the C group, the Dex1 group, and the Dex2 group were 22.5%, 5.0%, and 7.5%, respectively. The incidences of POD in the Dex1 group or the Dex2 group declined significantly as compared to the C group (both P<0.05). However, there is no difference in the incidence of POD between the Dex1 group and the Dex2 group (P>0.05). The incidences of POCD in the C group, the Dex1 group, and the Dex2 group were 30.0%, 12.5%, and 10.0%, respectively. The incidences of POCD in the Dex1 group and the Dex2 group declined significantly as compared to the C group (both P<0.05). And no obvious difference was seen in the incidence of POCD in the Dex1 group and the Dex2 group (P>0.05). Compared with the C group, the level of TNF-α and IL-1ß decreased and the level of IL-10 increased at each time points (from T1 to T4) in the Dex1 group and the Dex2 group (all P<0.05). Compared with the Dex1 group, the level of IL-1ß at T2 and IL-10 from T1 to T3 elevated in the Dex2 group (all P<0.05). Compared with the T0, the concentrations of NSE in C group at each time points (from T1 to T4) and in the Dex1 group and the Dex2 group from T1 to T3 increased (all P<0.05). Compared with the C group, the level of NSE decreased from T1 to T4 in the Dex1 group and the Dex2 group (all P<0.05). CONCLUSIONS: Intraoperative dexmedetomidine infusion can reduce the incidence of POCD and POD in elderly patients undergoing hepatic lobectomy, and the protective mechanism appears to involve the down-regulation of TNF-α and IL-1ß and upregulation of IL-10 expression, which lead to rebalance between proinflammation and anti-inflammation.