Ulinastatin May Significantly Improve Postoperative Cognitive Function of Elderly Patients Undergoing Spinal Surgery by Reducing the Translocation of Lipopolysaccharide and Systemic Inflammation

Effect of Surgery on Postoperative Levels of the Gut Homeostasis-Regulating Enzyme Intestinal Alkaline Phosphatase

BACKGROUND

Intestinal homeostasis is a crucial factor for complication-free short- and long-term postoperative recovery. The brush border enzyme intestinal alkaline phosphatase (IAP) is an important regulator of gut barrier function and intestinal homeostasis and prevents endotoxemia by detoxifying lipopolysaccharides (LPSs). As IAP is predominantly secreted by enterocytes in the duodenum, we hypothesized that pancreaticoduodenectomy (PD) leads to a significantly stronger decrease in IAP than other major abdominal surgery.

STUDY DESIGN

Pre- and postoperative blood, stool, and intestinal samples were collected from patients undergoing PD, as well as other major surgical procedures without duodenectomy. The samples were analyzed using enzyme histochemistry, the para -nitrophenyl phosphate method for IAP, and the limulus amebocyte lysate assay for LPS.

RESULTS

Overall, 88 patients were prospectively enrolled in the study. Fecal IAP activity negatively correlated with serum LPS (r = -0.3603, p = 0.0006). PD led to a significant decline in IAP compared to preoperative baseline levels (p < 0.0001). The decline in IAP correlated with the length of proximal small intestinal resection (r = 0.4271, p = 0.0034). Compared to controls, PD was associated with a much more pronounced reduction in IAP-also after adjusting for surgical trauma (operative time, blood loss; r = 0.4598, p = 0.0086). Simultaneously, PD triggered a clearly more prominent increase in serum LPS compared to controls (p = 0.0001). Increased postoperative LPS was associated with an elongated hospitalization (r = 0.7534, p = 0.0062) and more prominent in pancreatic cancer (p = 0.0009).

CONCLUSIONS

Based upon the functional roles for IAP, supplementation with exogenous IAP might be a new treatment option to improve short- and long-term outcome after PD.

Index of consciousness monitoring during general anesthesia may effectively enhance rehabilitation in elderly patients undergoing laparoscopic urological surgery: a randomized controlled clinical trial

BACKGROUND

Based on electroencephalogram (EEG) analysis, index of consciousness (IoC) monitoring is a new technique for monitoring anesthesia depth. IoC is divided into IoC1 (depth of sedation) and IoC2 (depth of analgesia). The potential for concurrent monitoring of IoC1 and IoC2 to expedite postoperative convalescence remains to be elucidated. We investigated whether combined monitoring of IoC1 and IoC2 can effectively enhances postoperative recovery compared with bispectral index (BIS) in elderly patients undergoing laparoscopic urological surgery under general anesthesia.

METHODS

In this prospective, controlled, double-blinded trail, 120 patients aged 65 years or older were arbitrarily assigned to either the IoC group or the control group (BIS monitoring). All patients underwent blood gas analysis at T1 (before anesthesia induction) and T2 (the end of operation). The Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) were administered to all patients at T0 (1 day before surgery) and T4 (7 days after surgery). Serum concentrations of C-reactive protein (CRP) and glial fibrillary acid protein (GFAP) were assessed at T1, T2, and T3 (24 h after surgery). Postoperative complications and the duration of hospitalization were subjected to comparative evaluation.

RESULTS

The incidence of postoperative cognitive dysfunction (POCD) was notably lower in the IoC group (10%) than in the control group (31.7%) (P = 0.003). Postoperative serum CRP and GFAP concentrations exhibited significant differences at time points T2 (CRP: P = 0.000; GFAP: P = 0.000) and T3 (CRP: P = 0.003; GFAP: P = 0.008). Postoperative blood glucose levels (P = 0.000) and the overall rate of complications (P = 0.037) were significantly lower in Group IoC than in Group control.

CONCLUSION

The employment of IoC monitoring for the management of elderly surgical patients can accelerate postoperative convalescence by mitigating intraoperative stress and reducing peripheral and central inflammatory injury.

TRIAL REGISTRATION

Chinese Clinical Trial Registry Identifier: ChiCTR1900025241 (17/08/2019).

Preoperative cerebrospinal fluid biomarkers may be associated with postoperative delirium in patients undergoing knee/hip arthroplasty: the PNDABLE study

BACKGROUND

In the global aging population, the incidence of postoperative delirium (POD) is increasing. Therefore, finding its effective predictive tools becomes crucial. We aimed to identify potential Cerebrospinal fluid (CSF)biomarkers for POD.

METHODS

A total of 825 patients undergoing knee/hip arthroplasty under combined spinal-epidural anesthesia were selected. The patients were aged 40 to 90 years with American Society of Anesthesiologists physical status I~II. The Mini-Mental State Examination was completed 1 day before the operation. CSF was extracted after successful spinal-epidural combined puncture, and α-synuclein (α-syn), amyloid beta₄₀ (Aβ₄₀), amyloid beta₄₂ (Aβ₄₂), t-Tau, phosphorylated Tau (p-Tau), progranulin (PGRN) and soluble triggering receptor expressed on myeloid cells 2 (sTREM2) in the CSF were measured by enzyme-linked immunosorbent assays (ELISA). The patient's operation time, anesthesia time, intraoperative blood loss and fluid input were also recorded. After the operation, the occurrence rate and severity of POD were determined by the Confusion Assessment Method and the Memorial Delirium Assessment Scale (MDAS), respectively. Patients were categorized into POD group and non-POD group. Logistic regression analysis was performed on the indicators with statistically significant differences, and the area under the ROC curve (AUC) was used to estimate the predictive accuracy of the biomarkers for POD.

RESULTS

A total of 92 patients developed POD and the incidence of POD was 11.15%. The results of the multivariable logistic regression showed that CSF t-Tau (P = 0.004, OR = 1.006, 95%CI 1.002~1.009) and α-syn (P = 0.004, OR = 1.001, 95%CI 1.000~1.001) were positively associated with the occurrence rate of POD, while Aβ₄₂ (P < 0.001, OR = 0.989, 95%CI 0.986~0.993), CSF PGRN (P = 0.002, OR = 0.999, 95%CI 0.999~1.000), Aβ₄₂/ t-Tau (P < 0.001, OR = 0.181, 95%CI 0.102~0.319) and Aβ₄₂/p-Tau (P < 0.001, OR = 0.617, 95%CI 0.526~0.725) were inversely proportional to the occurrence of POD. ROC curve analysis indicated that Aβ₄₂/t-Tau (AUC = 0.823), CSF Aβ₄₂ (AUC = 0.813), Aβ₄₂/p-Tau (AUC = 0.810), α-syn (AUC = 0.644) and PGRN (AUC = 0.638) could predict the occurrence rate of POD. The combination of all these biomarkers showed a greater AUC(0.896) than using any of them alone.

CONCLUSIONS

CSF Aβ₄₂, PGRN, α-syn, Aβ₄₂/t-Tau and Aβ₄₂/p-Tau might be associated with the occurrence rate of POD in patients undergoing knee/hip arthroplasty.

TRIAL REGISTRATION

Clinical Registration No. ChiCTR2000033439.

Targeting neuroinflammation as a preventive and therapeutic approach for perioperative neurocognitive disorders

Perioperative neurocognitive disorders (PND) is a common postoperative complication associated with regional or general anesthesia and surgery. Growing evidence in both patient and animal models of PND suggested that neuroinflammation plays a critical role in the development and progression of this problem, therefore, mounting efforts have been made to develop novel therapeutic approaches for PND by targeting specific factors or steps alongside the neuroinflammation. Multiple studies have shown that perioperative anti-neuroinflammatory strategies via administering pharmacologic agents or performing nonpharmacologic approaches exert benefits in the prevention and management of PND, although more clinical evidence is urgently needed to testify or confirm these results. Furthermore, long-term effects and outcomes with respect to cognitive functions and side effects are needed to be observed. In this review, we discuss recent preclinical and clinical studies published within a decade as potential preventive and therapeutic approaches targeting neuroinflammation for PND.

Ulinastatin attenuates spinal cord injury by targeting AMPK/NLRP3 signaling pathway

The AMPK and NLRP3 inflammasome signaling pathways are reported to participant in the inflammatory responses following spinal cord injury (SCI). Ulinastatin (ULI) is a urinary trypsin inhibitor with excellent anti-inflammatory effects, but the functions of ULI on SCI are rarely reported. Hence, this study was designed to investigate whether ULI could modulate SCI through regulating the AMPK/NLRP3 signaling pathway. Cell Counting Kit-8 (CCK-8) assays were used to investigate whether ULI had cytotoxic effects on BV-2 cells. Basso-Beattie-Bresnahan (BBB) scale, spinal cord water content detection, hematoxylin-eosin (HE) and Nissl stainings were used to investigate the protective effects of ULI on rat SCI. The expressions of inflammatory cytokines were detected by ELISA and RT-qPCR. The expressions of key proteins of AMPK and NLRP3 inflammasome were analyzed by western blot. The CCK-8 assays indicated that ULI did not significantly influence the viability of BV-2 cells at various concentrations below 10,000 U/ml. It was witnessed that ULI could dramatically inhibit the activation of NLRP3 inflammasome via activating the AMPK signaling pathway, thus relieving inflammatory responses. Besides, the in vivo experiment suggested that treatment with ULI remarkably relieve spinal cord edema, ameliorated spinal cord tissue architecture, and improved neurological function following SCI. The findings indicate that ULI significantly ameliorates neurological function following SCI by regulating the AMPK/NLRP3 inflammasome signaling pathway.

The Role of Gut Microbiota—Gut—Brain Axis in Perioperative Neurocognitive Dysfunction

With the aging of the world population and advances in medical and health technology, more and more elderly patients are undergoing anesthesia and surgery, and perioperative neurocognitive dysfunction (PND) is receiving increasing attention. The latest definition of PND, published simultaneously in November 2018 in 6 leading journals in the field of anesthesiology, clarifies that PND includes preoperatively cognitive impairment, postoperative delirium, delayed neurocognitive recovery, and postoperative cognitive dysfunction and meets the diagnostic criteria for neurocognitive impairment in the Diagnostic and Statistical Manual of Mental Disorders -fifth edition (DSM-5). The time frame for PND includes preoperatively and within 12 months postoperatively. Recent studies have shown that gut microbiota regulates central nervous function and behavior through the gut microbiota - gut - brain axis, but the role of the axis in the pathogenesis of PND remains unclear. Therefore, this article reviews the mechanism of the role of gut microbiota-gut-brain axis in PND, so as to help explore reasonable early treatment strategies.

Salubrious effects of ulinastatin and quercetin alone or in combination in endothelial dysfunction and vascular dementia

BACKGROUND

Vascular dementia is the second most prevalent form of dementia. Hypertension is the leading risk factor for endothelial dysfunction and the progression of dementia that is of vascular origin. This study investigates the role of ulinastatin (UTI) and quercetin alone as well as in combination in hypertension-induced endothelial dysfunction and vascular dementia (VaD).

METHOD

Two-kidney one-clip (2K1C) renovascular model was set up to induce hypertension in the Albino Wistar rats (males). Rats were assessed for mean arterial blood pressure, behavioral function (Morris water maze, attention set-shifting tests), vascular endothelial function, and biochemical levels (aortic superoxide anion and serum nitrite/nitrate), as well as brains' thiobarbituric acid reactive species-TBARS, reduced glutathione-GSH, interleukin-6, 10, tumor necrosis factor-TNF-α and acetylcholinesterase-AChE). UTI (10,000 U/kg, ip) and quercetin (60 mg/kg) were used alone and in combination for treatment. Donepezil (0.5 mg/kg) was used as a positive control.

RESULTS

2K1C rats showed impairment in learning, memory, executive functioning, and reversal learning. These rats further showed endothelial dysfunction as well as an increase in mean arterial blood pressure, brains' oxidative stress, inflammation, and AChE-activity. Treatment with UTI and quercetin alone as well in combination significantly attenuated the 2K1C model induced impairments in the behavioural, biochemical, and endothelial parameters.

CONCLUSION

2K1C renovascular hypertension-induced impairment in behavioural, biochemical, and endothelial parameters were attenuated by the treatment with UTI and quercetin alone as well as in combination. Therefore, the utility of these agents might be studied further to understand their full potential in hypertension-induced VaD.

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.

Effect of LncRNA OIP5-AS1/microRNA-186-5p on isoflurane-induced cognitive dysfunction in aged rats

BACKGROUND

Post-operative recognition dysfunction (POCD) is a kind of central nervous system complication that appears after operative anesthesia. Recent studies on the mechanism of long non-coding RNA (lncRNA) in neurodegenerative diseases are abundant.

AIMS

The study aimed to explore the expression pattern and role of lncRNA OIP5-AS1 in POCD and to investigate its underlying mechanism in old rats.

METHODS

The old rats were exposed to isoflurane to mimic the POCD in the elderly, and their cognitive function was tested via Morris water maze (MWM) test. Enzyme linked immunosorbent assay was applied for the concentration detection of inflammation and oxidative stress-related factors. Luciferase reporter assay was done for the target gene analysis.

RESULTS

Downregulation of OIP5-AS1 was accompanied by isoflurane treatment in rats, overexpression of OIP5-AS1 induced the rats to spend more time in the target quadrant, and shorten escape latency time. OIP5-AS1 inhibited the release of TNF-α, IL-6 and IL-1β, GSH and superoxide dismutase, decreased the activation of caspase-3, but promoted malondialdehyde release. miR-186-5p was a target miRNA of OIP5-AS1, and exhibited high expression in rats after isoflurane exposure. miR-186-5p can abolish the beneficial role of OIP5-AS1 against cognitive impairment, inflammatory response, oxidative stress and neuron apoptosis.

CONCLUSION

OIP5-AS1 plays a neuroprotective role in elderly POCD rats through sponging miR-186-5p, and it is related to OIP5-AS1/miR-186-5p mediated inflammatory response, oxidative stress and neuron apoptosis.

Clemastine Ameliorates Perioperative Neurocognitive Disorder in Aged Mice Caused by Anesthesia and Surgery

Perioperative neurocognitive disorder (PND) leads to progressive deterioration of cognitive function, especially in aged patients. Demyelination is closely associated with cognitive dysfunction. However, the relationship between PND and demyelination remains unclear. Here we showed that demyelination was related to the pathogenesis of PND. Clemastine, an antihistamine with potency in remyelination, was predicted to have a potential therapeutic effect on PND by next-generation sequencing and bioinformatics in our previous study. In the present study, it was given at 10 mg/kg per day for 2 weeks to evaluate the effects on PND in aged mice. We found that clemastine ameliorated PND and reduced the expression levels of inflammatory factors such as tumor necrosis factor alpha (TNF-α) and interleukin-1 beta (IL-1β). Further investigation suggested clemastine increased the expression of oligodendrocyte transcription factor 2 (OLIG2) and myelin basic protein (MBP) to enhance remyelination by inhibiting the overactivation of the WNT/β-catenin pathway. At the same time, the expression of post-synaptic density protein 95 (PSD95, or DLG4), brain-derived neurotrophic factor (BDNF), synaptosomal-associated protein 25 (SNAP25) and neuronal nuclei (NEUN) were also improved. Our results suggested that clemastine might be a therapy for PND caused by anesthetic and surgical factors in aged patients.

Efficacy of Ulinastatin and Sulforaphane Alone or in Combination in Rat Model of Streptozotocin Diabetes Induced Vascular Dementia

Objective

Vascular Dementia (VaD), is associated with metabolic conditions. Diabetes is a major risk factor for the development of VaD. This study investigates the efficacy of ulinastatin (UTI) and sulforaphane (SUL) in streptozotocin (STZ)-diabetes induced vascular endothelium dysfunction and related dementia.

Methods

Single dose STZ (50 mg/kg i.p.) was administered to Albino Wistar rats (male, 200−250 g). Morris water maze and attentional set shifting tests were used to assess the spatial learning, memory, reversal learning, and executive functioning in animals. Body weight, serum glucose, serum nitrite/nitrate, vascular endothelial function, aortic superoxide anion, brains’ oxidative markers (thiobarbituric acid reactive species-TBARS, reduced glutathione-GSH, superoxide dismutase-SOD, and catalase-CAT), inflammatory markers (IL-6, IL-10, TNF-a, and myeloperoxidase-MPO), acetylcholinesterase activity-AChE, blood brain barrier (BBB) permeability and histopathological changes were also assessed. UTI (10,000 U/kg) and SUL (25 mg/kg) were used alone as well as in combination, as the treatment drugs. Donepezil (0.5 mg/kg) was used as a positive control.

Results

STZ-administered rats showed reduction in body weight, learning, memory, reversal learning, executive functioning, impairment in endothelial function, BBB permeability, increase in serum glucose, brains’ oxidative stress, inflammation, AChE-activity, BBB permeability and histopathological changes. Administration of UTI and SUL alone as well as in combination, significantly and dose dependently attenuated the STZ-diabetes-induced impairments in the behavioral, endothelial, and biochemical parameters.

Conclusion

STZ administration caused diabetes and VaD which was attenuated by the administration of UTI and SUL. Therefore, these agents may be studied further for the assessment of their full potential in diabetes induced VaD.

Management Based on Multimodal Brain Monitoring May Improve Functional Connectivity and Post-operative Neurocognition in Elderly Patients Undergoing Spinal Surgery

Perioperative neurocognitive disorder (PND) is a common condition in elderly patients undergoing surgery. Sedation, analgesia, regional cerebral oxygen saturation (rSO₂), and body temperature are known to be associated with PND, but few studies have examined the contribution of these factors combined in detail. This prospective, randomized, controlled, double-blinded study investigated whether anesthesia management based on multimodal brain monitoring—an anesthesia management algorithm designed by our group—could improve the post-operative cognitive function and brain functional connectivity (FC) in elderly patients undergoing elective spinal surgery with general anesthesia. The patients (aged ≥65 years) were randomized into two groups [control (Group C), n = 12 and intervention (Group I), n = 14]. Patients in Group I were managed with multimodal brain monitoring (patient state index, spectral edge frequency, analgesia nociception index, rSO₂, and temperature), and those in Group C were managed with routine anesthesia management. All patients were pre- and post-operatively evaluated (7 days after surgery) with the Montreal Cognitive Assessment (MoCA). Amplitude of low-frequency fluctuation (ALFF) and FC were analyzed after resting-state functional MRI. Serum C-reactive protein (CRP) and lipopolysaccharide levels were measured, and the correlation between FC and changes in inflammatory marker levels was analyzed. Mean post-operative MoCA score was higher in Group I (24.80 ± 2.09) than in Group C (22.56 ± 2.24) (p = 0.04), with no difference in PND incidence between groups (28.57 vs. 16.67%; p = 0.47). Group I also showed significantly increased ALFF values in several brain regions after surgery (p < 0.05), and FC between the left hippocampus and left orbital inferior frontal gyrus (FG), left middle FG, left superior temporal gyrus, and left precentral gyrus was enhanced (p < 0.05), which was negatively correlated with the change in serum CRP (pre vs. post-intervention) (R = −0.58, p = 0.01). These results suggest that management of elderly patients undergoing surgery by multimodal brain monitoring may improve post-operative neurocognition and FC by reducing systemic inflammation.

Clinical Trial Registration:http://www.chictr.org.cn/index.aspx, identifier: ChiCTR1900028024.

Effect of Ulinastatin on Early Postoperative Cognitive Dysfunction in Elderly Patients Undergoing Surgery: A Systemic Review and Meta-Analysis

Background: Postoperative cognitive dysfunction (POCD) is associated with neuroinflammation by triggering the systemic inflammatory responses. Related studies have demonstrated that ulinastatin, which is a urinary trypsin inhibitor, inhibited the release of inflammatory mediators and improved postoperative cognitive function in elderly patients undergoing major surgery. However, there are controversial results put forwarded by some studies. This systemic review aimed to evaluate the effect of ulinastatin on POCD in elderly patients undergoing surgery. Methods: We searched PubMed, Embase, Cochrane Library, Web of Science, and Ovid to find relevant randomized controlled trials (RCTs) of ulinastatin on POCD in elderly patients undergoing surgery. The primary outcomes included the incidence of POCD and the Mini-Mental State Examination (MMSE) scores. The secondary outcome was the levels of inflammatory cytokines such as tumor necrosis factor (TNF)-α, S100β, C-reactive protein (CRP), interleukin (IL)-6, and IL-10. RevMan 5.3 was used to conduct the meta-analysis. Results: Ten RCTs were included finally. Compared with controls, ulinastatin significantly reduced the incidence of POCD [risk ratio (RR) = 0.29, 95% CI 0.21-0.41, test of RR = 1: Z = 7.05, p < 0.00001]. In addition, patients in the ulinastatin group have lower levels of TNF-α, S100β, CRP, and IL-6 and higher level of IL-10 in serum following surgery. Conclusion: These findings suggested that ulinastatin can be used as an anti-inflammatory drug for POCD prevention in elderly patients undergoing surgery. Systematic Review Registration Number: CRD42019137449.

Ulinastatin inhibits NLRP3-induced apoptosis in a PD cell model

Background

Emerging evidence suggests that inflammation induced by the inflammasome plays a crucial role in the course of Parkinson’s disease (PD). Ulinastatin (UTI) has shown significant anti-inflammatory effects. However, few studies have examined whether UTI protects neurons through its anti-inflammatory effects in PD. The purpose of this study is to determine whether UTI exerts neuroprotection in a PD cell model and to explore the mechanisms.

Methods

SH-SY5Y cells and nerve growth factor (NGF)-treated PC12 cells were used to establish MPP⁺ induced PD cell models. Cells were pre-treated with UTI, then cell viabilities were detected using the MTT assay. Lactate dehydrogenase (LDH) release was detected using the LDH release assay kit. Inflammatory factors such as IL-1β, IL-6, and TNF-α were detected using ELISA. The expression levels of TH, NLRP3, caspase-1, ASC, IL-1β, and IL-18 were measured using western blotting, and DA release was detected using HPLC. A NLRP3 activator Nigericin was used to verify the effect of NLRP3 in the neuroprotective mechanism of UTI.

Results

We observed decreased cell viability, increased apoptosis, and increased inflammatory factors such as IL-1β, IL-6, and TNF-α in the MPP⁺ induced PD model. We also found decreased DA secretion and TH expression, as well as increased NLRP3, caspase-1, ASC, IL-1α, and IL-18 expression in the MPP⁺ induced PD model. These changes were significantly attenuated by UTI pre-treatment in a dose dependent manner. NLRP3 activator Nigericin markedly increased LDH release, accelerated apoptosis, increased inflammation levels and decreased DA secretion and TH expression, suggesting that Nigericin eliminated the neuroprotective effect of UTI on MPP⁺ treated cells.

Conclusions

Our data demonstrated that UTI pre-treatment performed a neuroprotective role in the MPP⁺ induced PD cell models by inhibiting the NLRP3 pathway.

Preoperative red cell distribution width predicts postoperative cognitive dysfunction after coronary artery bypass grafting

We assessed the relationship between red blodd cell distribution width (RDW) and postoperative cognitive dysfunction (POCD) after coronary artery bypass grafting (CABG) in patients who usually had obvious hemodynamic changes. We enrolled 362 coronary heart disease patients who received CABG. POCD was assessed through neuropsychological examination at 21 days after operation. Demographics, history of diseases, blood biochemical parameters and perioperative data were collected. The receiver operating characteristic (ROC) curve was used to find the best cut-off value of RDW for diagnosis of POCD. Logistic regression was used to explore the relationship between RDW and POCD. The 21-day incidence of POCD in patients receiving CABG was 27.1% (98/362). The RDW of POCD patients was significantly higher than in the non-POCD patients (17.4 vs. 13.2). The sensitivity and specificity of RDW for predicting POCD were 82.7 and 64.8%, respectively. The POCD patients also tended to be older and had higher fasting plasma glucose, hypersensitive c-reactive protein, tumor necrosis factor-α, white blood cell levels and longer surgery time. No significant differences were found in other parameters. The 21-day neuropsychological test results were better in the POCD patients than the non-POCD patients. After adjustment of potential factors, the preoperative high RDW was still associated with an increased risk of POCD (odds ratio (OR) = 2.52, 95% confidence interval (CI): 1.28–4.31). Our study indicates that preoperative RDW is significantly elevated in POCD patients receiving CABG. The elevated preoperative RDW is associated with an increased risk of POCD and preoperative RDW can be an independent predictor of POCD.

Elamipretide (SS-31) Improves Functional Connectivity in Hippocampus and Other Related Regions Following Prolonged Neuroinflammation Induced by Lipopolysaccharide in Aged Rats

Neuroinflammation has been recognized as a major cause for neurocognitive diseases. Although the hippocampus has been considered an important region for cognitive dysfunction, the influence of hippocampal neuroinflammation on brain functional connectivity (FC) has been rarely studied. In this study, lipopolysaccharide (LPS) was used to induce systemic inflammation and neuroinflammation in the aged rat brain, while elamipretide (SS-31) was used for treatment. Systemic and hippocampal inflammation were determined using ELISA, while astrocyte responses during hippocampal neuroinflammation were determined by interleukin 1 beta (IL-1β)/tumor necrosis factor alpha (TNFα) double staining immunofluorescence. Oxidative stress was determined by reactive oxidative species (ROS), electron transport chain (ETC) complex, and superoxide dismutase (SOD). Short- (<7 days) and long-term (>30 days) learning and spatial working memory were tested by the Morris water maze (MWM). Resting-state functional magnetic resonance imaging (rs-fMRI) was used to analyze the brain FC by placing seed voxels on the left and right hippocampus. Compared with the vehicle group, rats with the LPS exposure showed an impaired MWM performance, higher oxidative stress, higher levels of inflammatory cytokines, and astrocyte activation in the hippocampus. The neuroimaging examination showed decreased FC on the right orbital cortex, right olfactory bulb, and left hippocampus on day 3, 7, and 31, respectively, after treatment. In contrast, rats with SS-31 treatment showed lower levels of inflammatory cytokines, less astrocyte activation in the hippocampus, and improved MWM performance. Neuroimaging examination showed increased FC on the left-parietal association cortex (L-PAC), left sensory cortex, and left motor cortex on day 7 with the right flocculonodular lobe on day 31 as compared with those without SS-31 treatment. Our study demonstrated that inhibiting neuroinflammation in the hippocampus not only reduces inflammatory responses in the hippocampus but also improves the brain FC in regions related to the hippocampus. Furthermore, early anti-inflammatory treatment with SS-31 has a long-lasting effect on reducing the impact of LPS-induced neuroinflammation.

Exosome α-Synuclein Release in Plasma May be Associated With Postoperative Delirium in Hip Fracture Patients

Background: Little is known about the underlying mechanisms of the similarities in the core features of postoperative delirium (POD) and α-synuclein (α-syn)-related cognitive disorders. We herein investigated associations between fluctuated levels of exosomal α-syn in the plasma and POD presentation in geriatric hip fracture patients.

Methods: We conducted an observational, prospective, and 1:1 matched (on age older than 65, hip fracture diagnosis, American Society of Anesthesiologist’ (ASA) physical status, duration of surgery, and intraoperative bleeding) case-control study: POD cases and non-POD controls were selected from the overall cohort by using Confusion Assessment Method (CAM). Delirium severity was measured by the Memorial Delirium Assessment Scale (MDAS). Plasma exosome levels of α-syn were examined preoperatively and at the time that POD was diagnosed, by using an established immunocapture technology based on a putative brain-cell-specific marker. Circulating concentrations of interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were also determined. The relationship between α-syn levels and POD risk, as well as the association between α-syn and MDAS scores and plasma cytokines, were assessed.

Results: POD incidence was 8.4% (17/202). Postoperative α-syn were either elevated or lowered. As primary outcome variables, the change of α-syn in POD patients was significantly higher than non-POD ones (21.0 ± 29.3 pg.ml⁻¹ vs.1.9 ± 20.0, P = 0.047). The α-syn alteration was positively correlated to MDAS (r = 0.436, P = 0.010) and the change of IL-6 (r = 0.383, P = 0.025).

Conclusions: Exosome α-syn release in plasma may be associated with the POD development which might be due to systemic inflammation.

Clinical Trial Registration: www.clinicaltrials.gov, identifier ChiCTR-IPR-17012301.

Prior Presentation: The abstract of this work has been selected for presentation in the 2019 ANESTHESIOLOGY Journal Symposium “What’s New with the old,” and it has been present in the ASA 2019 annual meeting October 21st, 2019 in Florida.

Electric vagal nerve stimulation inhibits inflammation and improves early postoperation cognitive dysfunction in aged rats

BACKGROUND

This study aimed to evaluate effects of electric vagal nerve stimulation on early postoperation cognitive dysfunction in aged rats.

METHODS

A total of 33 male Sprague Dawley rats were selected and assigned randomly to three groups, control group (C, n = 10), splenectomy group (S, n = 10) and splenectomy+vagal nerve stimulation group (SV, n = 13). Behavior and memory of rats were evaluated by Open Field Test and Morris Water Maze. Levels of TNF-α, IL-6 and IL-10 in serum were measured by ELISA. The level of TNF-α protein in hippocampus was assessed by Western blotting. rt-PCR was used to detect mRNA expression of NF-κB in hippocampus.

RESULTS

During anesthesia/operation, vital life signs of rats were stable. In SV group, vagal nerve stimulation decreased heart rate lower than 10% of basic level and kept it at a stable range by regulating stimulation intensity. After stimulation stop, heart rate returned to the basic level again. This indicated that the model of vagal nerve stimulation was successful. Serum levels of TNF-α and IL-6 increased by the operation/anesthesia, but they decreased with vagal nerve stimulation (all P < 0.05). TNF-α protein and mRNA expression of NF-κB in hippocampus were also eliminated by vagal nerve stimulation compared to S group (P < 0.05). Results of Morris Water Maze showed escape latency of postoperation in S group was significantly longer than C group (P < 0.05), and times of crossing platform in S group was lower than that of C group (P < 0.05). Although escape latency of postopration in SV group was shorter than that of S group, there was no significant difference between two groups. Meanwhile there were no significant differences of behavior test in Open Field test between three groups, although vagal nerve stimulation improved partly active explore behavior compared to S group.

CONCLUSION

The inflammation caused by operation and general anesthesia was an important reason of early postoperation cognitive dysfunction, and electric vagal nerve stimulation could inhibit the inflammation. Meanwhile, vagal nerve stimulation could ameliorate early postoperation cognitive dysfunction partly, but its protective effects were not enough and should be studied and improved in future.

[Effect of ulinastatin on isoflurane-induced neuronal apoptosis in the hippocampus of rats]

OBJECTIVE

To investigate the effect of ulinastatin pretreatment on isoflurane-induced mitochondria-dependent neuronal apoptosis in the hippocampus of rats.

METHODS

Thirty-six male SD rats were randomly assigned into control group, isoflurane group and ulinastatin group. In the latter two groups, the rats were subjected to acute exposure to 0.75% isoflurane for 6 h and pretreated with 50 000 U/kg of ulinastatin before isoflurane exposure, respectively. After the treatments, apoptosis of the hippocampal neurons was detected using TUNEL assay, and the mitochondrial membrane potential (△ ψm) was measured using JC-1 mitochondrial membrane potential kit; cytochrome C release and caspase-3 activity were examined with Western blotting, and intracellular reactive oxygen species (ROS) was detected using the fluorescent probe H2DCFDA.

RESULTS

Compared with those in the control group, the rats with acute exposure to isoflurane showed markedly increased TUNEL-positive cells in the hippocampus (P &lt; 0.05), which were obviously reduced by ulinastatin pretreatment (P &lt; 0.05). The △ψm of the hippocampal neurons was significantly reduced after isoflurane exposure (P &lt; 0.05), and was partly recovered by ulinastatin pretreatment (P &lt; 0.05). Acute exposure to isoflurane resulted in obviously increased cellular ROS, cytochrome C release and caspase-3 activity in the hippocampal neurons (P &lt; 0.05), and these changes were significantly inhibited by ulinastatin pretreatment (P &lt; 0.05).

CONCLUSIONS

Ulinastatin pretreatment provides neuroprotection against isoflurane-induced apoptosis of the hippocampal neurons in rats possibly by inhibiting mitochondria-dependent apoptosis pathway.