Postoperative delirium and neurocognitive disorders

Integrative analysis of circRNA networks in postoperative cognitive dysfunction

OBJECTIVE

In the quest to decipher the molecular intricacies of Postoperative Cognitive Dysfunction (POCD), this study focused on circular RNA (circRNA) and their regulatory networks.

MATERIALS AND METHODS

Analyzing the Gene Expression Omnibus Series (GSE) 147277 dataset, we pinpointed 10 differentially expressed circRNAs linked to POCD.

RESULTS

The ensuing competing endogenous RNA (ceRNA) network, featuring pivotal players like Homo sapiens(hsa)_circ_0003424 and hsa-miR-193b-5p, provided a comprehensive understanding of the molecular players at play in POCD.

CONCLUSION

Additionally, the Protein-Protein Interaction (PPI) network spotlighted 10 core Hub genes, including phosphatase and tensin homolog (PTEN) and signal transducer and activator of transcription 3(STAT3), shedding light on potential therapeutic targets.

Mitochondrial fatty acid oxidase CPT1A ameliorates postoperative cognitive dysfunction by regulating astrocyte ferroptosis

BACKGROUND

Postoperative cognitive dysfunction (POCD) is a significant surgery-related complication marked by cognitive decline. Studies indicated that neuroinflammation, ferroptosis, and mitochondrial fatty acid metabolism might play parts in POCD, and might be mediated by Carnitine palmitoyl transferase 1a (CPT1A), but requires further investigations. Therefore, this study aims to investigate the mechanism of mitochondrial fatty acid oxidase CPT1A on mitochondrial function, ferroptosis, and inflammation in POCD pathogenesis.

METHODS

SVG P12 astrocytes were used to investigate CPT1A's control over mitochondrial function, ferroptosis, and inflammation affecting neurons. CPT1A was overexpressed using shRNA, with or without oligomycin to modulate mitochondrial function. Co-culture of these astrocytes with neurons, under similar conditions, assessed CPT1A's impact on neuron damage via ferroptosis and inflammation. Gene and protein expressions of CPT1A, SYN, PSD95 were measured via RT-PCR and WB. Detection of JC-1, mitochondrial oxygen consumption rate (OCR), ROS, Fe2+ concentration, MOD, SOD and GSH/GSSG using kits was conducted to explore mitochondrial function and ferroptosis. Inflammation was quantified by ELISA for IL-6, IL-1β, and TGF-β.

RESULTS

We successfully established CPT1A overexpression and knockdown models in astrocytes, confirming CPT1A's ability to enhance mitochondrial membrane potential. Elevated CPT1A levels led to improved mitochondrial function, synaptic integrity, reduced oxidative stress, maintained iron homeostasis, and attenuated neuroinflammation, as reflected by increased SYN, PSD95, OCR, GSH and SOD, decreased ROS,GSSG, MDA, iron levels, and lowered inflammatory factors expression. Treatment with oligomycin reversed these protective effects, demonstrating the dependency of CPT1A's benefits on intact mitochondrial respiration. In co-culture experiments with hippocampal neurons, astrocytes with manipulated CPT1A levels, particularly those co-treated with oligomycin, exacerbated neuronal mitochondrial dysfunction, oxidative stress, iron accumulation, and inflammation.

CONCLUSION

Overexpression of mitochondrial fatty acid oxidase CPT1A might improve synaptic integrity and rescue POCD by ameliorating astrocyte ferroptosis and neuroinflammation.

Intra-operative blood transfusions raise the risk of postoperative delirium and impede functional recovery in elderly hip fracture patients: a propensity score-matched study

BACKGROUND

This retrospective analysis was performed to investigate the potential influence of intra-operative blood transfusion (IBT) in patients aged 65 years or older with intertrochanteric fractures (IF) who underwent intramedullary fixation.

METHODS

The outcomes of interest included the incidence of postoperative delirium (POD), pain score at discharge, length of hospital stay (LOS), functional outcomes, and mortality. The study included all surgically treated patients with IF between Jan. 2018 and Dec. 2021. Data on patient demographics, injury-related factors, surgical procedures, intraoperative details, in-hospital information, and postoperative outcomes were collected. In order to mitigate potential confounding and selection bias, the researchers employed the propensity score matching (PSM) technique using a 1:1 ratio via the caliper matching method. Following PSM, the association between IBT and outcome analyses was assessed using McNemar's Chi-square tests. Additionally, the Spearman correlations between IBT, POD and postoperative functional outcomes were computed.

RESULTS

Out of the initial 2159 consecutive patients screened, a final sample of 1681 individuals was included, consisting of 1278 in the non-IBT group and 403 in the IBT group. After PSM, each group comprised 298 participants. The disparities in POD rate and functional outcomes became significant after employing propensity score-based matching (P < 0.001 and 0.029, respectively), despite their lack of significance prior to matching. There were no notable distinctions observed in other operation-related data, LOS, and crude mortality rates at 30-day, 90-day, and 12-month intervals before and after PSM. Furthermore, incidence of POD (P = 0.006) and functional outcomes (P = 0.013) were significantly associated with IBT.

CONCLUSION

In conclusion, IBT significantly increases the incidence of POD and hinders postoperative functional recovery in elderly patients with hip fracture.

Transthyretin, a novel prognostic marker of POCD revealed by time-series RNA-sequencing analysis

Postoperative cognitive dysfunction (POCD) is defined as a declined cognition, measured by neuropsychological tests, that persists for months or even longer after surgery. Heterogeneities in the diagnosis of POCD usually involve differences in the test batteries, the cutoffs, and the timing of assessments. Although peripheral and CSF markers of neuroinflammation have been shown to correlate with increased risk of POCD, most of them are non-specific and cannot be used for POCD diagnosis. These factors hampered the understanding of the pathogenesis of POCD as well as the development of effective preventions/treatments. In this study, we found Ttr in a panel of potential POCD biomarkers identified using time-series analysis of the transcriptomes and proteomes of the hippocampi of POCD mice that diagnosed on individual basis with composite Z-scores of test batteries consisting of Y maze and open field test. Compared with their counterparts without POCD, the levels of Ttr were significantly lower in the peripheral circulation as well as in the hippocampi of the mice developed POCD at all indicated time points after surgery. The levels of peripheral TTR in human patients with delayed neurocognitive recovery were found to be reduced at 24 h after abdominal surgery, compared with those who did not. Endogenous expression of Ttr was verified in microglia cells both in vitro and in vivo. Results of in vitro assay indicated a potential role of Ttr in ameliorating LPS-induced microglial priming and protecting the differentiation of oligodendrocyte progenitor cells (OPCs) in proinflammatory microenvironment, which was one of the determinant factors in regulating the pathological progression of POCD.

Cerebral Oximetry Index-Guided Blood Pressure Management During Cardiopulmonary Bypass Reduces Postoperative Delirium in Patients with Acute Type A Aortic Dissection

OBJECTIVE(S)

To investigate whether cerebral oximetry index (COx)-guided blood pressure management during cardiopulmonary bypass (CPB) could reduce postoperative delirium (POD) in patients undergoing acute type A aortic dissection (ATAAD) repair.

DESIGN

A prospective, randomized controlled trial.

SETTING

Patients undergoing ATAAD repair with CPB.

PARTICIPANTS

157 patients with ATAAD were randomly assigned to COx-guided management (n = 76) or conventional blood pressure management (n = 81) during CPB.

INTERVENTIONS

COx-guided blood pressure management (intervention group) versus conventional blood pressure management (control group) during CPB.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was POD incidence within the first 7 postoperative days (significantly lower in the COx-guided group: 15% v 30%, p = 0.039). Secondary outcomes included lower delirium severity (Delirium Rating Scale-Revised-98 score: 5 v 10, p = 0.033), shorter POD duration (0 v 2 days, p = 0.045), reduced postoperative cerebral infarction (1.3% v 8.6%, p = 0.037), and reduced acute kidney injury (27.6% v 43.2%, p = 0.042) in the COx-guided group. Shorter time to extubation (16.9 v 18.4 hours, p = 0.027) and reduced intensive care unit stay (7.3 v 8.2 days, p = 0.042) were observed in the COx-guided group.

CONCLUSIONS

COx-guided blood pressure management during CPB was associated with reduced incidence and severity of POD following ATAAD surgery. This approach also showed potential benefits in reducing postoperative complications and improving early recovery outcomes. Further multicenter studies are needed to confirm these findings.

Bibliometric Analysis of Neuroinflammation and Postoperative Cognitive Dysfunction

BACKGROUND

The occurrence and development of postoperative cognitive dysfunction (POCD) are closely linked to neuroinflammation. This bibliometric analysis aims to provide novel insights into the research trajectory, key research topics, and potential future development trends in the field of neuroinflammation-induced POCD.

METHODS

The Web of Science Core Collection (WoSCC) database was searched to identify publications from 2012 to 2023 on neuroinflammation-induced POCD. Bibliometric analysis, involving both statistical and visual analyses, was conducted using CiteSpace, VOSviewer, and the R software.

RESULTS

Research on neuroinflammation-induced POCD has exhibited an increasing trend over the past 12 years. China had the highest number of publications, Nanjing Medical University had the most collaboration with other institutions, Zhiyi Zuo was the most published author, and the Journal of Neuroinflammation served as the primary publication in the field of neuroinflammation-induced POCD. The most frequent keyword was POCD. Keyword clustering analysis indicated that the predominant cluster is dexmedetomidine. Burst detection revealed that postoperative delirium (POD), perioperative neurocognitive disorders (PND), apoptosis, and epigenetic modifications were the future research trends.

CONCLUSIONS

Our analysis identified the following key research areas associated with neuroinflammation-induced POCD: anesthesia, surgery, dexmedetomidine, NLRP3 inflammasome, and mechanism of neuroinflammation-induced POCD. The potential future research topics comprise POD, PND, apoptosis, and epigenetic modifications.

Withaferin a modulation of microglia autophagy mitigates neuroinflammation and enhances cognitive function in POCD

With the aging process of the global population and the development of medical technology, the cases of postoperative cognitive dysfunction (POCD) are also increasing. Due to the complexity of the pathogenesis, urgent treatment has been sought. Neuroinflammation induced by the accumulation of lipid droplets (LDs) in microglia has been closely watched in recent years and is also considered to be an important cause of nerve damage. Our study found that derived from Withania somnifera, Withaferin A (WA) could reduce the accumulation of LDs in the hippocampus of POCD mice, inhibit the expression of inflammatory factor interleukin-1β (IL-1β), and improve the cognitive ability of mice. Further in vitro experimental studies showed that WA increased the autophagy level of microglia, promoted the degradation of LDs, and reduced the production of inflammatory factors. In this regard, our comprehensive research endeavor holds the potential to furnish novel insights into therapeutic strategies aimed at addressing POCD and its associated neural impairments.

Cognitive prehabilitation for older adults undergoing elective surgery: a systematic review and narrative synthesis

Background

Perioperative cognitive maintenance and protection in older adults is an important patient safety imperative. In addition to foundational care, one area of growing interest is integrating cognitive prehabilitation into the surgical trajectory. This review aimed to evaluate the effectiveness and safety of cognitive prehabilitation on cognitive functional capacity and postoperative cognitive outcomes among older adults undergoing elective surgery.

Methods

The MEDLINE, Embase, CENTRAL, CINAHL, PsycINFO, PEDro, CBM, CNKI, WANFANG, and VIP databases were systematically searched up to September 5, 2024, to identify randomized controlled trials published for English or Chinese. Two authors independently completed the study selection process, data extraction process and methodological quality assessment. The Patient, Intervention, Comparison, Outcome, Study design framework was used to construct the search strategy. The predefined primary outcomes of interest included the incidence of postoperative delirium (POD) and the incidence of delayed neurocognitive recovery (dNCR). The quality of the studies was evaluated by the PEDro scale. Owing to the small number of trials and clinical and methodological diversity, a narrative synthesis was undertaken in accordance with the Synthesis Without Meta-analysis guidelines. This study was conducted and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. The certainty of the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation system.

Results

Six studies were analysed. These trials involved 645 total participants, with 316 in the intervention group (mean age, 66.0-73.8 years; 38.4-77.8% male) and 329 in the comparator group (mean age, 67.5-72.6 years; 31.8-88.9% male). The effects of preoperative cognitive training on reducing the incidence of dNCR, the incidence of POD, the length of hospital stay and the incidence of postsurgical complications as well as improving postoperative global cognitive function and activities of daily living are quite uncertain. The results of this study should be interpreted with caution owing to the limited number of trials and low to very low certainty of evidence.

Conclusion

Current evidence on the effectiveness and safety of cognitive prehabilitation on cognitive and noncognitive outcomes in older patients undergoing elective surgery is limited and unclear.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=277191, Identifier CRD42021277191.

Preoperative gut microbiota of POCD patients induces pre- and postoperative cognitive impairment and systemic inflammation in rats

BACKGROUND

Postoperative cognitive dysfunction (POCD) is common following surgery in elderly patients. The role of the preoperative gut microbiota in POCD has attracted increasing attention, but the potential underlying mechanisms remain unclear. This research aimed to investigate the impact of the preoperative gut microbiota on POCD.

METHODS

Herein, we analyzed the preoperative gut microbiota of POCD patients through a prospective specimen collection and retrospective blinded evaluation study. Then, we transferred the preoperative gut microbiota of POCD patients to antibiotic-treated rats and established POCD model by abdominal surgery to explore the impact of the preoperative gut microbiota on pre- and postoperative cognitive function and systemic inflammation. The gut microbiota was analyzed using 16S rRNA sequencing analysis. The Morris water maze test was performed to evaluate learning and memory abilities. The inflammatory cytokines TNF-α, IL-1β and IL-6 in the serum and hippocampus were measured by ELISA. Microglia were examined by immunofluorescence staining for Iba-1.

RESULTS

Based on the decrease in the postoperative MMSE score, 24 patients were identified as having POCD and were matched with 24 control patients. Compared with control patients, POCD patients exhibited higher BMI and lower preoperative MMSE score. The preoperative gut microbiota of POCD patients had lower bacterial richness but a larger distribution, decreased abundance of Firmicutes and increased abundance of Proteobacteria than did that of control patients. Compared with rats that received preoperative fecal samples of control patients, rats that received preoperative fecal samples of POCD patients presented an increased abundance of Desulfobacterota, decreased cognitive function, increased levels of TNF-α and IL-1β in the serum, increased levels of TNF-α and greater microglial activation in the hippocampus. Additionally, correlation analysis revealed a positive association between the abundance of Desulfobacterota and the level of serum TNF-α in rats. Then, we performed abdominal surgery to investigate the impact of the preoperative gut microbiota on postoperative conditions, and the surgery did indeed cause POCD and inflammatory response. Notably, compared with rats that received preoperative fecal samples of control patients, rats that received preoperative fecal samples of POCD patients displayed exacerbated cognitive impairment; increased levels of TNF-α, IL-1β and IL-6 in the serum and hippocampus; and increased activation of microglia in the hippocampus.

CONCLUSIONS

Our findings suggest that the preoperative gut microbiota of POCD patients can induce preoperative and aggravate postoperative cognitive impairment and systemic inflammation in rats. Modulating inflammation by targeting the gut microbiota might be a promising approach for preventing POCD.

Dexmedetomidine enhances Mitophagy via PINK1 to alleviate hippocampal neuronal Pyroptosis and improve postoperative cognitive dysfunction in elderly rat

Postoperative cognitive dysfunction (POCD) is a common complication in elderly surgical patients, significantly affecting their quality of life. Dexmedetomidine (Dex), an anesthetic, has shown promise in alleviating POCD, but its underlying mechanism remains unclear. This study aims to explore how Dex improves POCD in aged rats by targeting the PINK1-mediated mitochondrial autophagy pathway, reducing caspase-1/11-GSDMD-induced hippocampal neuronal pyroptosis. Transcriptome sequencing identified 300 differentially expressed genes enriched in the mitochondrial autophagy pathway in Dex-treated POCD rat hippocampal tissue, with Pink1 as a key candidate. In a POCD rat model, Dex treatment upregulated hippocampal PINK1 expression. In vitro experiments using H19-7 rat hippocampal neurons revealed that Dex enhanced mitochondrial autophagy and suppressed neuronal pyroptosis by upregulating PINK1. Further mechanistic validation demonstrated that Dex activated PINK1-mediated mitochondrial autophagy, inhibiting caspase-1/11-GSDMD-induced neuronal pyroptosis. In vivo experiments confirmed Dex's ability to reduce caspase-1/11-GSDMD-dependent hippocampal neuronal pyroptosis and improve postoperative cognitive function in aged rats. Dexmedetomidine improves postoperative cognitive dysfunction in elderly rats by enhancing mitochondrial autophagy via PINK1 upregulation, mitigating caspase-1/11-GSDMD-induced neuronal pyroptosis.

Association of postoperative delirium with hypotension in critically ill patients after cardiac surgery: a prospective observational study

BACKGROUND

Postoperative delirium (POD), an acute and variable disturbance in cognitive function, is an intricate and elusive phenomenon that occurs after cardiac surgery. Despite progress in surgical techniques and perioperative management, POD remains a formidable challenge, imposing a significant burden on patients, caregivers, and healthcare systems.

METHODS

This prospective observational study involved 307 patients who underwent cardiac surgery. Data on the occurrence of delirium, clinical parameters, and postoperative characteristics were collected. A multivariate analysis was performed to assess the relationship between POH and POD.

RESULTS

Sixty-one patients (21%) developed delirium, with an average onset of approximately 5 days postoperatively and a duration of approximately 6 days. On multivariate analysis, POH was significantly associated with POD, and the adjusted odds ratios indicated that patients with POH were more likely to develop delirium (OR, 5.61; p = 0.006). Advanced age (OR, 1.11; p = 0.002), emergency surgery (OR, 8.31; p = 0.001), and on-pump coronary artery bypass grafting were identified as risk factors of POD. Patients who developed delirium were typically older, more likely to be male, and had higher morbidity rates than those who did not.

CONCLUSION

POH is significantly associated with delirium in critically ill patients after cardiac surgery. Surgical complexity and advanced age contribute to the risk of developing POD and poor postoperative outcomes.

Role of the circRNA_34414/miR-6960a-5p/SIRT3 axis in postoperative delirium via CA1 Vglut1+ neurons in older mice

AIMS

Postoperative delirium (POD) is a common neurological complication in elderly patients after anesthesia/surgery. The main purpose of this study is to explore the effect of circRNA-targeted miRNA regulating SIRT3 on mitochondrial function through ceRNA mechanism under the surgical model of tibial fracture and to further explore the potential mechanism of postoperative delirium mediated by circRNA, so as to provide new ideas for clinical diagnosis and prevention of POD.

METHODS

The surgical model of tibial fracture under sevoflurane anesthesia caused acute delirium-like behavior in elderly mice. We observed that the decrease of SIRT3 and mitochondrial dysfunction was related to POD, and miRNA and circRNA (circRNA_34414) related to SIRT3 were further studied. Through luciferase and RAP, we observed that circRNA_34414, as a miRNA sponge, was involved in the regulation of SIRT3 expression.

RESULTS

Postoperative delirium in elderly mice showed decreased expression of hippocampal circRNA_34414, increased expression of miR-6960-5p, decreased expression of SIRT3, and impaired mitochondrial membrane potential. Overexpression of circRNA_34414, or knockdown of miR-6960-5p, or overexpression of SIRT3 in hippocampal CA1 glutamatergic neurons significantly upregulated hippocampal SIRT3 expression, increased mitochondrial membrane potential levels, and significantly ameliorated postoperative delirium in aged mice; CircRNA_34414 ameliorates postoperative delirium in mice, possibly by targeting miR-6960-5p to upregulate SIRT3.

CONCLUSIONS

CircRNA_34414 is involved in the improvement of postoperative delirium induced by anesthesia/surgery by upregulating SIRT3 via sponging miR-6960-5p.

Relationship between cortical brain atrophy, delirium, and long-term cognitive decline in older surgical patients

In older patients, delirium after surgery is associated with long-term cognitive decline (LTCD). The neural substrates of this association are unclear. Neurodegenerative changes associated with dementia are possible contributors. We investigated the relationship between brain atrophy rates in Alzheimer's disease (AD) and cognitive aging signature regions from magnetic resonance imaging before and one year after surgery, LTCD assessed by the general cognitive performance (GCP) score over 6 years post-operatively, and delirium in 117 elective surgery patients without dementia (mean age = 76). The annual change in cortical thickness was 0.2(1.7) % (AD-signature p = 0.09) and 0.4(1.7) % (aging-signature p = 0.01). Greater atrophy was associated with LTCD (AD-signature: beta(CI) = 0.24(0.06-0.42) points of GCP/mm of cortical thickness; p < 0.01, aging-signature: beta(CI) = 0.55(0.07-1.03); p = 0.03). Atrophy rates were not significantly different between participants with and without delirium. We found an interaction with delirium severity in the association between atrophy and LTCD (AD-signature: beta(CI) = 0.04(0.00-0.08), p = 0.04; aging-signature: beta(CI) = 0.08(0.03-0.12), p < 0.01). The rate of cortical atrophy and severity of delirium are independent, synergistic factors determining postoperative cognitive decline in the elderly.

Perioperative Blood Transfusion and Delirium after Total Knee or Hip Arthroplasty: Retrospective Analysis

We investigated the type of blood component transfusion associated with increased postoperative delirium. Adult patients who underwent total knee arthroplasty (TKA) or total hip arthroplasty (THA) between 2017 and 2022 were included. Delirium was evaluated and treated within two days after surgery. A total of 6737 patients (4112 TKA/2625 THA) were retrospectively studied; 2.48% of patients in the TKA (n = 102) and THA (n = 65) groups had postoperative delirium. The blood transfusion (BT) and non-BT groups had similar percentages of patients who experienced postoperative delirium (3.34 vs. 2.35%, p = 0.080). In the multivariable logistic regression model, BT was not associated with postoperative delirium-adjusted odds ratio (aOR): 1.03, confidence interval (CI): 0.62, 1.71; p = 0.917. Moreover, transfusion of packed red blood cells (p = 0.651), platelets (p = 0.998), and cryoprecipitate (p = 0.999) were not associated with delirium. However, transfusion of fresh frozen plasma was associated with a 5.96-fold higher incidence of delirium-aOR: 5.96, 95% CI: 2.72, 13.04; p < 0.001. In conclusion, perioperative BT was not associated with postoperative delirium in patients who underwent TKA or THA. However, FFP transfusion was associated with an increased incidence of postoperative delirium.

Electroencephalogram Biomarkers from Anesthesia Induction to Identify Vulnerable Patients at Risk for Postoperative Delirium

BACKGROUND

Postoperative delirium is a common complication in elderly patients undergoing anesthesia. Even though it is increasingly recognized as an important health issue, the early detection of patients at risk for postoperative delirium remains a challenge. This study aims to identify predictors of postoperative delirium by analyzing frontal electroencephalogram at propofol-induced loss of consciousness.

METHODS

This prospective, observational single-center study included patients older than 70 yr undergoing general anesthesia for a planned surgery. Frontal electroencephalogram was recorded on the day before surgery (baseline) and during anesthesia induction (1, 2, and 15 min after loss of consciousness). Postoperative patients were screened for postoperative delirium twice daily for 5 days. Spectral analysis was performed using the multitaper method. The electroencephalogram spectrum was decomposed in periodic and aperiodic (correlates to asynchronous spectrum wide activity) components. The aperiodic component is characterized by its offset (y intercept) and exponent (the slope of the curve). Computed electroencephalogram parameters were compared between patients who developed postoperative delirium and those who did not. Significant electroencephalogram parameters were included in a binary logistic regression analysis to predict vulnerability for postoperative delirium.

RESULTS

Of 151 patients, 50 (33%) developed postoperative delirium. At 1 min after loss of consciousness, postoperative delirium patients demonstrated decreased alpha (postoperative delirium: 0.3 μV2 [0.21 to 0.71], no postoperative delirium: 0.55 μV2 [0.36 to 0.74]; P = 0.019] and beta band power [postoperative delirium: 0.27 μV2 [0.12 to 0.38], no postoperative delirium: 0.38 μV2 [0.25 to 0.48]; P = 0.003) and lower spectral edge frequency (postoperative delirium: 10.45 Hz [5.65 to 15.04], no postoperative delirium: 14.56 Hz [9.51 to 16.65]; P = 0.01). At 15 min after loss of consciousness, postoperative delirium patients displayed a decreased aperiodic offset (postoperative delirium: 0.42 μV2 (0.11 to 0.69), no postoperative delirium: 0.62 μV2 [0.37 to 0.79]; P = 0.004). The logistic regression model predicting postoperative delirium vulnerability demonstrated an area under the curve of 0.73 (0.69 to 0.75).

CONCLUSIONS

The findings suggest that electroencephalogram markers obtained during loss of consciousness at anesthesia induction may serve as electroencephalogram-based biomarkers to identify at an early time patients at risk of developing postoperative delirium.

EDITOR’S PERSPECTIVE

Integrative proteomics and metabolomics data analysis exploring the mechanism of brain injury after cardiac surgery in chronic stress rats

OBJECTIVE

Preoperative chronic stress (CS) is associated with postoperative brain injury in patients undergoing open heart cardiac surgery. This research is to explore the potential molecular biological mechanisms of brain damage following cardiac surgery in preoperative CS rats by the analyses combining proteomics and metabolomics.

METHODS

We constructed the chronic unpredictable stress (CUS) and cardiac surgery models in adult rats. We proved the brain injury in CUS cardiac surgery rats by Hematoxylin-Eosin (H&E) staining, followed by separating the hippocampal tissue and investigating the potential mechanisms of brain injury by the methods of data-independent acquisition proteomics and untargeted metabolomics.

RESULTS

The signaling pathways of glycoproteins and metabolism of amino acids were the main possible mechanisms of brain injury in CUS rats following cardiac surgery according to the proteomics and metabolomics. In addition, the pathways of animo acids metabolism such as the pathways of lysine degradation and β-alanine metabolism may be the main mechanism of cardiac surgery related brain injury in preoperative CUS rats.

CONCLUSIONS

The pathways of animo acids metabolism such as lysine degradation and β-alanine metabolism may be the potential mechanisms of brain injury in CUS rats following cardiac surgery. We should focus on the varieties of bioproteins and metabolites in these pathways, and related changes in other signaling pathways induced by the two pathways.

Unveiling the role of astrocytes in postoperative cognitive dysfunction

Alzheimer's disease (AD) is the most common neurodegenerative disorder, characterized by progressive cognitive decline and the accumulation of amyloid-beta plaques, tau tangles, and neuroinflammation in the brain. Postoperative cognitive dysfunction (POCD) is a prevalent and debilitating condition characterized by cognitive decline following neuroinflammation and oxidative stress induced by procedures. POCD and AD are two conditions that share similarities in the underlying mechanisms and pathophysiology. Compared to normal aging individuals, individuals with POCD are at a higher risk for developing AD. Emerging evidence suggests that astrocytes, the most abundant glial cells in the central nervous system, play a critical role in the pathogenesis of these conditions. Comprehensive functions of astrocyte in AD has been extensively explored, but very little is known about POCD may experience late-onset AD pathogenesis. Herein, in this context, we mainly explore the multifaceted roles of astrocytes in the context of POCD, highlighting their involvement in neuroinflammation, neurotransmitter regulation, synaptic plasticity and neurotrophic support, and discuss how POCD may augment the onset of AD. Additionally, we discuss potential therapeutic strategies targeting astrocytes to mitigate or prevent POCD, which hold promise for improving the quality of life for patients undergoing surgeries and against AD in the future.

Risk factors for postoperative delirium in elderly patients undergoing heart valve surgery with cardiopulmonary bypass

BACKGROUND

The aim of this study was to identify the risk factors for postoperative delirium (POD) in elderly patients undergoing heart valve surgery with cardiopulmonary bypass (CPB).

METHODS

Elderly patients undergoing elective heart valve surgery with CPB in The First Affiliated Hospital of Wenzhou Medical University between March 2022 and March 2023 were selected for this investigation. They were divided into a POD group and a non-POD group. Their baseline information was collected and recorded, and the patients were subjected to neurocognitive function assessment using the Mini-Mental State Examination and the Montreal Cognitive Assessment scales before surgery. We also recorded their intraoperative indicators such as duration of surgery, duration of CPB, duration of aortic cross-clamp, blood transfusion, and postoperative indicators such as duration of mechanical ventilation, postoperative 24-hour drainage volume, and pain score. Regional cerebral oxygen saturation was monitored intraoperatively by near-infrared spectroscopy based INVOS5100C Regional Oximeter. Patients were assessed for the occurrence of POD using Confusion Assessment Method for the Intensive Care Unit, and logistic regression analysis of risk factors for POD was performed.

RESULTS

The study finally included 132 patients, with 47 patients in the POD group and 85 ones in the non-POD group. There were no significant differences in baseline information and preoperative indicators between the two groups. However, marked differences were identified in duration of surgery, duration of CPB, duration of aortic cross-clamp, duration of postoperative mechanical ventilation, postoperative length of stay in cardiac intensive care unit, postoperative length of hospital stay, intraoperative blood transfusion, postoperative pain score, and postoperative 24-hour drainage volume between the two groups (p < 0.05). Additionally, the two groups had significant differences in rScO2 at each intraoperative time point and in the difference of rScO2 from baseline at each intraoperative time point (p < 0.05). Multivariate logistic regression analysis showed that duration of surgery > 285 min (OR, 1.021 [95% CI, 1.008-1.035]; p = 0.002), duration of postoperative mechanical ventilation > 23.5 h (OR, 6.210 [95% CI, 1.619-23.815]; p = 0.008), and postoperative CCU stay > 3.5 d (OR, 3.927 [95% CI, 1.046-14.735]; p = 0.043) were independent risk factors of the occurrence of POD while change of rScO2 at T1>50.5 (OR, 0.832 [95% CI 0.736-0.941]; p = 0.003) was a protective factor for POD.

CONCLUSION

Duration of surgery duration of postoperative mechanical ventilation and postoperative CCU stay are risk factors for POD while change of rScO2 at T1 is a protective factor for POD in elderly patients undergoing heart valve surgery with CPB.

Ultrasound-guided serratus anterior plane block to prevent neurocognitive impairment in elderly patients after thoracoscopic lobectomy: protocol for a single-centre, double-blind, randomised controlled trial

INTRODUCTION

Postoperative neurocognitive dysfunction (PND), including postoperative delirium (POD), is a common complication in elderly patients after major surgeries, often leading to poor postoperative recovery. Although the pathological mechanism underlying PND is still unclear, postoperative pain is strongly associated with the development of PND. The ultrasound-guided serratus anterior plane block (SAPB) has been reported to relieve postoperative pain in thoracic surgery. Therefore, this prospective trial hypothesises that SAPB may reduce the incidence of PND in the elderly undergoing thoracoscopic lobectomy.

METHODS AND ANALYSIS

This study is designed as a single-centre, double-blind, randomised controlled clinical trial. A total of 256 elderly patients scheduled to undergo thoracoscopic lobectomy at Shanghai Pulmonary Hospital will be randomly assigned to general anaesthesia group or SAPB group. The primary outcome is the incidence of PND 7 days postoperatively or before discharge from hospital. The secondary outcomes include the occurrence of POD, the postoperative pain scores, Quality of Recovery at 1-2 days postoperatively and incidence of PND at 3 months postoperatively. The levels of fasting blood glucose in peripheral blood will be examined before and 1-2 days postoperatively.

ETHICS AND DISSEMINATION

The trial has been approved by the Clinical Research Ethics Committee of Shanghai Pulmonary Hospital (identifier: K20-290). All participants will be required to provide written informed consent before any protocol-specific procedures. Findings will be disseminated in a peer-reviewed journal and in national and/or international meetings to guide future practice.

TRIAL REGISTRATION NUMBER

ChiCTR2100052633.

The risk factors for and the frequency and outcomes of subsyndromal delirium among patients who have undergone cardiac surgery: a protocol for systematic review and meta-analysis

INTRODUCTION

Several key symptoms must be present for the accurate diagnosis of patients with postoperative cardiac delirium. Some patients present with symptoms of delirium but do not meet the diagnostic criteria for delirium; such individuals are considered to have having subsyndromal delirium (SSD). SSD is associated with misdiagnosis and poor outcomes. However, to date, no systematic review (SR) has examined the frequency of, risk factors for, and outcomes of SSD among adults who have undergone cardiac surgery.

METHODS AND ANALYSIS

The aim of this SR is to identify those studies that have explored SSD after cardiac surgery. MeSH and free entry terms associated with "subsyndromal delirium" and "subclinical delirium" will be used to search for relevant studies. The PubMed, Web of Science, OVID, Cochrane Library, CINAHL, EMBASE, PsycINFO, China National Knowledge Infrastructure, Wanfang data, VIP database and SinoMed will be searched from inception to the date of retrieval without any restrictions. The primary outcomes will be the frequency of SSD, the risk factors for SSD, and the outcomes of SSD. Analyses will be performed using STATA V.16.0, and descriptive analyses will be performed if the data are not suitable for meta-analysis (ie, data with significant heterogeneity or from different comparisons).

ETHICS AND DISSEMINATION

The SR will examine the frequency of, risk factors for and outcomes of SSD in adults who have undergone cardiac surgery. The results will provide guidance for the identification of knowledge gaps in this field, and areas for further research will be highlighted. The review protocol will be submitted for publication in peer-reviewed journals for dissemination of the findings. Individual patient data will not be included in this protocol, so ethical approval will not be needed.

PROSPERO REGISTRATION NUMBER

CRD42022379211.

The effect of intravenous lidocaine on postoperative cognitive dysfunction: a systematic review and meta-analysis

BACKGROUND

Postoperative cognitive dysfunction (POCD) has been reported as a significant complication in elderly patients. Various methods have been proposed for reducing the incidence and severity of POCD. Intravenous lidocaine administration has been reported in the literature to reduce POCD, but the effect of lidocaine remains controversial.

METHODS

We screened Medline, Embase, Cochrane Library, and China National Knowledge Infrastructure (up to April 2022) databases following a search strategy for intravenous lidocaine on POCD. We also screened related bibliographies on lidocaine for POCD. Ten articles comprising 1517 patients were selected and analyzed. We divided the postoperative follow-up period as follows: short term (<30 days), medium term (30-90 days), and long term (>90 days).

OUTCOMES

We found that lidocaine could attenuate the overall incidence of POCD, especially in the short term. There were no differences between lidocaine and placebo on the overall severity of POCD.

CONCLUSION

Lidocaine administered intravenously could attenuate the overall incidence of POCD and its severity in the short term.

Intravenous lidocaine improves postoperative cognition in patients undergoing laparoscopic colorectal surgery: a randomized, double-blind, controlled study

BACKGROUND

The risk of postoperative cognitive dysfunction(POCD) in laparoscopic surgery should not be overlooked. Intravenous lidocaine can reduce perioperative inflammatory response in patients undergoing laparoscopic surgery, while the effect of intraoperative intravenous lidocaine on postoperative cognitive function in patients undergoing laparoscopic colorectal cancer surgery has not been well studied. We investigated whether intraoperative lidocaine improves postoperative cognitive function after laparoscopic radical resection for colorectal cancer.

METHODS

We conducted a prospective, randomized double blinded controlled trial to investigate the effect of intravenous lidocaine on rapid postoperative recovery in patients undergoing laparoscopic radical resection of colorectal cancer. The patients were randomly assigned to receive either intravenous lidocaine or saline. The primary outcome was cognitive dysfunction defined by a decrease from pre- to postoperative ≥ 2 of the Mini-Mental State Examination (MMSE) score, at the 3rd and the 7th postoperative days. Secondary outcomes were the MMSE raw score and parameters of the patients' postoperative recovery such as agitation and length of stay in the post-anaesthesia care unit (PACU), length of hospital stay, markers of inflammation (white blood cell count and CRP), and incidence of complications.

RESULTS

Seventy-three patients in the lidocaine group and 77 patients in the control group completed the trial. The rate of cognitive dysfunction was lower in the lidocaine group than that in the control group, both at the 3rd (18.57% vs. 63.64% for each group respectively; RR = 0.26, 95%CI = 0.19-0.32; p < 0.0001) and at the 7th postoperative day (12.33% vs. 53.25% for each group respectively; RR = 0.28, 95%CI = 0.22-0.35; P < 0.001). The postoperative MMSE scores were also higher in the lidocaine group than in the control group both at the 3rd (median 25 vs. 24 respectively) and at the 7th postoperative day (26 vs. 24 respectively). Also, patients in the lidocaine group displayed a lower white blood cell count than the control group at the 1st postoperative day (8.5 ± 2.7 vs. 10.4 ± 3.3; p < 0. 001). No differences were evidenced for the other secondary outcomes.

CONCLUSIONS

Intraoperative intravenous lidocaine can significantly improve postoperative cognitive function in patients undergoing laparoscopic radical resection of colorectal cancer.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (16/1/2022, registration number: ChiCTR2200055683).

Postoperative Application of Dexmedetomidine is the Optimal Strategy to Reduce the Incidence of Postoperative Delirium After Cardiac Surgery: A Network Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Previous pairwise meta-analyses demonstrated the efficacy and safety of dexmedetomidine in preventing postoperative delirium (POD) after cardiac surgery; however, the optimal time of applying dexmedetomidine remains unclear.

OBJECTIVE

This network meta-analysis aimed to determine the optimal time of using dexmedetomidine to reduce the incidence of POD following cardiac surgery.

METHODS

We first retrieved eligible randomized controlled trials (RCTs) from previous meta-analyses, and then an updated search was performed to identify additional RCTs in PubMed, Embase, and the Cochrane library from January 1, 2021 to October 31, 2021. Two authors screened literature, collected data, and evaluated bias risk of eligible studies. Finally, we performed Bayesian network analysis using R version 3.6.1 with the "gemtc" and "rjags" package.

RESULTS

Eighteen studies with 2636 patients were included, and all studies were identified from previous meta-analyses. Results showed that postoperative dexmedetomidine reduced the risk of POD compared with normal saline (NS) (odds ratio [OR], 0.13; 95% credible interval [CrI], 0.03-0.35) and propofol (PRO) (OR, 0.19; 95%CrI, 0.04-0.66). Postoperative dexmedetomidine was associated with a lower incidence of POD compared with perioperative dexmedetomidine (OR, 0.21; 95% CrI, 0.04-0.82). Moreover, postoperative dexmedetomidine had the highest probability of ranking best (90.98%), followed by intraoperative dexmedetomidine (46.83%), PRO (36.94%), perioperative dexmedetomidine (30.85%), and NS (60.02%).

CONCLUSION AND RELEVANCE

Dexmedetomidine reduces the incidence of POD compared with PRO and NS in patients undergoing cardiac surgery, and postoperative application of dexmedetomidine is the optimal time.

The Effect of Consultation-Liaison Psychiatry on Postoperative Delirium in Elderly Hip Fracture Patients in the General Hospital

OBJECTIVE

The low recognition rate of postoperative delirium has gradually aroused clinical attention in China. The present study was to investigate the impact of consultation-liaison psychiatry on postoperative delirium in elderly hip fracture patients.

METHODS

From March 2012 to September 2013, 89 patients with hip fractures hospitalized in Wuhan Mental Health Center were included in this prospective study as the consultation-liaison group. A total of 81 patients selected from August 2010 to February 2012 were defined as the conventional group. The delirium was evaluated using the confusion assessment method (CAM) recommended by the American Psychiatric Association guidelines.

RESULTS

There was no difference of sex, age, trauma, surgical methods, and anesthesia between two groups (p > 0.05). The consultation rate of consultation-liaison group was significantly higher than that of conventional group (37.07% vs 17.28%, p < 0.05). After the consultation, there were 26 cases (78%) and nine cases (64%) of delirium in the consultation-liaison and conventional group, respectively (p > 0.05). In the consultation-liaison group, three patients (9.09%) were diagnosed with anxiety and three patients (9.09%) were diagnosed with depression, while in the conventional group, three patients (21.42%) were diagnosed with communication and one patient (7.14%) was diagnosed with depression. In addition, this study showed the incidence of delirium in consultation-liaison group was significantly higher than that of conventional group (29.21% vs 11.11%, p < 0.05). The average hospital stay in consultation-liaison group was significantly lower than that of conventional group (11.42 ± 2.63 vs. 15.17 ± 2.38 days, p < 0.01).

CONCLUSION

Consultation-liaison psychiatry could improve the recognition rate of postoperative delirium in elderly hip fracture patients, shorten hospitalization time. The training of mental health knowledge for non-psychiatrists could improve the ability of early identification and treatment of delirium.

Effects of Remote Ischemic Preconditioning on Postoperative Cognitive Dysfunction in Elderly Patients with Laparoscopic Cholecystectomy

Purpose

We hypothesized that remote ischemic preconditioning (RIPC) could improve postoperative cognitive dysfunction (POCD) in elderly patients following laparoscopic cholecystectomy (LC).

Patients and Methods

Eighty-eight patients were randomly assigned to either the control or the RIPC group. The RIPC was applied on the right upper limb using a blood pressure cuff inflating 200 mmHg, consisting of 3 cycles of 5 min ischemia and 5 min reperfusion. Serum concentrations of Neuron-specific Enolase (NSE) and Brain-Derived Neurotrophic Factor (BDNF) were collected at one-day preoperative (T0), at the end of the operation (T4) and one-day postoperative (T5). Z score was tested at T0 and 3 days after the operation (T6). POCD was determined if there were two Z scores ≥1.96 at the same time or an average Z score ≥1.96.

Results

There was no significant difference in the Z score of each test between the two groups at T0 (P > 0.05). Notably, the duration of Stroop test C was significantly shorter in the RIPC group than that in the Control group at T6 (P = 0.01). POCD occurred in 1/44 (2.3%) patients in the RIPC group and 8/44 (18.2%) patients in the control group at T6 (P=0.035). In addition, serum NSE concentration was significantly decreased, but serum BDNF concentration was increased compared with the control group at T4 and T5 (P<0.001).

Conclusion

RIPC could reduce the incidence of POCD in elderly patients after laparoscopic cholecystectomy.

Transcutaneous Electrical Acupoint Stimulation for Preventing Postoperative Delirium: A Meta-Analysis

Objective

This meta-analysis of randomized controlled trials (RCTs) aims to evaluate the efficacy and safety of transcutaneous electrical acupoint stimulation (TEAS) for postoperative delirium (POD) in surgical patients.

Methods

Based on database searches of the Wanfang, China National Knowledge Infrastructure (CNKI), VIP, Chinese Biology Medicine (CBM), PubMed, Cochrane Library, and Web of Science, relevant RCTs published before December 30, 2022, were extracted. Outcome indicators included the incidence of POD, changes in Confusion Assessment Method (CAM) scores, Visual Analogue Scale (VAS) scores, and the intraoperative consumption of anesthetics. Data were pooled and analyzed by Review Manager 5.3, and publication bias detection was conducted using Stata 17.0.

Results

A meta-analysis containing 715 experimental and 717 control participants from 12 RCTs was performed. The overall results showed that TEAS had obvious superiority with a lower incidence of POD on any day during the postoperative 1 week. In subgroup analyses, the CAM scores on the third postoperative day were significantly lower in the TEAS group than in the control group (MD = -0.52, 95% CI: -1.02 to -0.03, P = 0.04), the VAS scores on the first postoperative day were significantly lower in the TEAS group than in the control group (MD = -0.19, 95% CI: -0.36 to -0.02, P = 0.03), the consumption of propofol and remifentanil were both significantly lower in the TEAS group compared with the control group (MD = -23.1, 95% CI: -37.27 to -8.94, P = 0.001; MD = -105.69, 95% CI: -174.20 to -37.19, P = 0.002). No serious adverse events of TEAS were reported in any of the referenced studies.

Conclusion

TEAS has an obvious curative effect in preventing POD and pain in the earlier stage of surgical patients. It could be a promising assisted anesthesia technique in the future.

The Future of Cardiothoracic Surgical Critical Care Medicine as a Medical Science: A Call to Action

Cardiothoracic surgical critical care medicine (CT-CCM) is a medical discipline centered on the perioperative care of diverse groups of patients. With an aging demographic and an increase in burden of chronic diseases the utilization of cardiothoracic surgical critical care units is likely to escalate in the coming decades. Given these projections, it is important to assess the state of cardiothoracic surgical intensive care, to develop goals and objectives for the future, and to identify knowledge gaps in need of scientific inquiry. This two-part review concentrates on CT-CCM as its own subspeciality of critical care and cardiothoracic surgery and provides aspirational goals for its practitioners and scientists. In part one, a list of guiding principles and a call-to-action agenda geared towards growth and promotion of CT-CCM are offered. In part two, an evaluation of selected scientific data is performed, identifying gaps in CT-CCM knowledge, and recommending direction to future scientific endeavors.

Risk Factors for Delirium after Deep Brain Stimulation Surgery under Total Intravenous Anesthesia in Parkinson's Disease Patients

BACKGROUND

Postoperative delirium (POD) is associated with perioperative complications and mortality. Data on the risk factors for delirium after subthalamic nucleus deep brain stimulation (STN-DBS) surgery is not clarified in Parkinson's disease (PD) patients receiving total intravenous anesthesia. We aimed to investigate the risk factors for delirium after STN-DBS surgery in PD patients.

METHODS

The retrospective cohort study was conducted, including 131 PD patients who underwent STN-DBS for the first time under total intravenous anesthesia from January to December 2021. Delirium assessments were performed twice daily for 7 days after surgery or until hospital discharge using the confusion assessment method for the intensive care unit. Multivariate logistic regression analysis was used to determine the risk factor of POD.

RESULTS

In total, 22 (16.8%) of 131 patients were in the POD group, while the other 109 patients were in the Non-POD group. Multivariate logistic regression analysis showed that preoperative Mini-mental State Examination score [odds ratio = 0.855, 95% confidence interval = 0.768-0.951, p = 0.004] and unified Parkinson's disease rating scale part 3 (on state) score (odds ratio = 1.061, 95% confidence interval = 1.02-1.104, p = 0.003) were independently associated with delirium after surgery.

CONCLUSIONS

In this retrospective cohort study of PD patients, a lower Mini-mental State Examination score and a higher unified Parkinson's disease rating scale part 3 (on state) score were the independent risk factors for delirium after STN-DBS surgery in PD patients under total intravenous anesthesia.

Effect of combined use of cerebral oximetry and electroencephalogram monitoring on the incidence of perioperative neurocognitive disorders in adult cardiac and non-cardiac surgery: A systematic review of randomized and non-randomized trials

Background: There is insufficient evidence to recommend using either intraoperative cerebral oximetry or (processed) electroencephalogram (EEG) alone for preventing perioperative neurocognitive disorders (PNDs). Objective: To evaluate the effectiveness of combined use of cerebral oximetry and electroencephalogram-guided anesthesia on the incidence of PNDs in adult patients undergoing cardiac and non-cardiac interventions. Methods: A PICOS - based systematic review of English articles using Pubmed and Embase (from inception to August 2022) was performed. There were no exclusion criteria regarding the type of the study. Abstract proceedings and new study protocols or ongoing studies were not included. Review articles were analyzed in search of eligible references. All possible terms that were illustrative of PNDs were used. Results: Among the 63 full manuscripts that were analyzed in detail, 15 met the inclusion criteria. We found 2 retrospective, 8 prospective observational and 5 randomized controlled trials of which 1 did not evaluate the use of neuromonitoring in the randomization process. The definition and the methods used to diagnose PNDs were very heterogeneous. Only 8 studies used an algorithm to avoid/treat cerebral oxygen desaturation and/or to treat EEG abnormalities. Overall, there was a tendency towards less PNDs in studies where such an algorithm was used. Conclusions: Our results suggest that integrating information obtained from cerebral oximetry and an EEG monitor may reduce the incidence of PNDs whenever an adapted algorithm is used to improve brain function.

Automated machine learning-based model for the prediction of delirium in patients after surgery for degenerative spinal disease

OBJECTIVE

This study used machine learning algorithms to identify critical variables and predict postoperative delirium (POD) in patients with degenerative spinal disease.

METHODS

We included 663 patients who underwent surgery for degenerative spinal disease and received general anesthesia. The LASSO method was used to screen essential features associated with POD. Clinical characteristics, preoperative laboratory parameters, and intraoperative variables were reviewed and were used to construct nine machine learning models including a training set and validation set (80% of participants), and were then evaluated in the rest of the study sample (20% of participants). The area under the receiver-operating characteristic curve (AUROC) and Brier scores were used to compare the prediction performances of different models. The eXtreme Gradient Boosting algorithms (XGBOOST) model was used to predict POD. The SHapley Additive exPlanations (SHAP) package was used to interpret the XGBOOST model. Data of 49 patients were prospectively collected for model validation.

RESULTS

The XGBOOST model outperformed the other classifier models in the training set (area under the curve [AUC]: 92.8%, 95% confidence interval [CI]: 90.7%-95.0%), validation set (AUC: 87.0%, 95% CI: 80.7%-93.3%). This model also achieved the lowest Brier Score. Twelve vital variables, including age, serum albumin, the admission-to-surgery time interval, C-reactive protein level, hypertension, intraoperative blood loss, intraoperative minimum blood pressure, cardiovascular-cerebrovascular disease, smoking, alcohol consumption, pulmonary disease, and admission-intraoperative maximum blood pressure difference, were selected. The XGBOOST model performed well in the prospective cohort (accuracy: 85.71%).

CONCLUSION

A machine learning model and a web predictor for delirium after surgery for the degenerative spinal disease were successfully developed to demonstrate the extent of POD risk during the perioperative period, which could guide appropriate preventive measures for high-risk patients.

A crosstalk between circular RNA, microRNA, and messenger RNA in the development of various brain cognitive disorders

Patients with Alzheimer's disease (AD), Parkinson's disease (PD), traumatic brain injury (TBI), stroke, and postoperative neurocognitive disorder (POND) are commonly faced with neurocognitive disorders with limited therapeutic options. Some non-coding ribonucleic acids (ncRNAs) are involved in the development of various brain cognitive disorders. Circular RNAs (circRNAs), a typical group of ncRNAs, can function as competitive endogenous RNAs (ceRNAs) to dysregulate shared microRNAs (miRNAs) at post-transcription level, inhibiting regulation of miRNAs on their targeted messenger RNAs (mRNAs). circRNAs are abundant in central nervous system (CNS) diseases and cause brain disorders, but the exact roles of circRNAs are unclear. The crosstalk between circRNA, miRNA, and mRNA plays an important role in the pathogenesis of these neurocognitive dysfunction diseases and abnormal conditions including AD, PD, stroke, TBI, and POND. In this review, we summarized the participation of circRNA in neuroglial damage and inflammation. Finally, we aimed to highlight the regulatory mechanisms of circRNA–miRNA–mRNA networks in the development of various brain cognitive disorders and provide new insights into the therapeutics of these diseases.

Postoperative Delirium in Neurosurgical Patients: Recent Insights into the Pathogenesis

Postoperative delirium (POD) is a complication characterized by disturbances in attention, awareness, and cognitive function that occur shortly after surgery or emergence from anesthesia. Since it occurs prevalently in neurosurgical patients and poses great threats to the well-being of patients, much emphasis is placed on POD in neurosurgical units. However, there are intricate theories about its pathogenesis and limited pharmacological interventions for POD. In this study, we review the recent insights into its pathogenesis, mainly based on studies within five years, and the five dominant pathological theories that account for the development of POD, with the intention of furthering our understanding and boosting its clinical management.

Ferroptosis is involved in regulating perioperative neurocognitive disorders: emerging perspectives

Since the twenty-first century, the development of technological advances in anesthesia and surgery has brought benefits to human health. However, the adverse neurological effects of perioperative-related factors (e.g., surgical trauma, anesthesia, etc.) as stressors cannot be ignored as well. The nervous system appears to be more "fragile" and vulnerable to damage in developing and aging individuals. Ferroptosis is a novel form of programmed cell death proposed in 2012. In recent years, the regulation of ferroptosis to treat cancer, immune system disorders, and neurodegenerative diseases have seen an unprecedented surge of interest. The association of ferroptosis with perioperative neurocognitive disorders has also received much attention. Cognitive impairment can not only affect the individual's quality of life, but also impose a burden on the family and society. Therefore, the search for effective preventive and therapeutic methods to alleviate cognitive impairment caused by perioperative-related factors is a challenge that needs to be urgently addressed. In our review, we first briefly describe the connection between iron accumulation in neurons and impairment of brain function during development and aging. It is followed by a review of the pathways of ferroptosis, mainly including iron metabolism, amino acid metabolism, and lipid metabolism pathway. Furthermore, we analyze the connection between ferroptosis and perioperative-related factors. The surgery itself, general anesthetic drugs, and many other relevant factors in the perioperative period may affect neuronal iron homeostasis. Finally, we summarize the experimental evidence for ameliorating developmental and degenerative neurotoxicity by modulating ferroptosis. The suppression of ferroptosis seems to provide the possibility to prevent and improve perioperative neurocognitive impairment.

Effects of subanaesthetic S-ketamine on postoperative delirium and cognitive function in elderly patients undergoing non-cardiac thoracic surgery: a protocol for a randomised, double-blinded, placebo-controlled and positive-controlled, non-inferiority trial (SKED trial)

INTRODUCTION

Postoperative delirium (POD) is a common and distressing complication after thoracic surgery. S-ketamine has neuroprotective properties as a dissociative anaesthetic. Emerging literature has indicated that S-ketamine can reduce cognitive impairment in patients with depression. However, the role of S-ketamine in preventing POD remains unknown. Therefore, this study aims to evaluate the effect of intraoperative prophylactic S-ketamine compared with that of dexmedetomidine on the incidence of POD in elderly patients undergoing non-cardiac thoracic surgery.

METHODS AND ANALYSIS

This will be a randomised, double-blinded, placebo-controlled, positive-controlled, non-inferiority trial that enrolled patients aged 60-90 years undergoing thoracic surgery. The patients will be randomly allocated in a ratio of 1:1:1 to S-ketamine, dexmedetomidine or normal saline placebo groups using computer-generated randomisation with a block size of six. The primary outcome will be the incidence of POD within 4 days after surgery and this will be assessed using a 3-Minute Diagnostic Confusion Assessment Method two times per day. The severity and duration of POD, the incidence of emergence delirium, postoperative pain, quality of sleep, cognitive function, and the plasma concentrations of acetylcholine, brain-derived neurotrophic factor, tumour necrosis factor-α and incidence of adverse events will be evaluated as secondary outcomes.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the Institutional Review Board of the Cancer Hospital and the Institute of Guangzhou Medical University (ZN202119). At the end of the trial, we commit to making a public disclosure available, regardless of the outcome. The public disclosure will include a publication in an appropriate journal and an oral presentation at academic meetings.

TRIAL REGISTRATION NUMBER

ChiCTR2100052750 (NCT05242692).

Short Sleep Duration on the Night Before Surgery Is Associated With Postoperative Cognitive Decline in Elderly Patients: A Prospective Cohort Study

As the world is rapidly aging, and the number of elderly patients who undergo surgery is rising, postoperative cognitive decline among those patients has become an increasing healthcare problem. Although understanding the risk factors and mechanisms underlying the pathogenesis of postoperative cognitive decline is critically important from a preventative viewpoint, such knowledge and evidence are lacking. A growing body of evidence suggest an association between cognitive function and sleep duration. The purpose of this study was to investigate the association between postoperative cognitive function and sleep duration on the night before surgery using a wearable sleep tracker. In this 6-month prospective cohort study, we analyzed data from 194 patients aged ≥ 65 years who underwent elective non-cardiac and non-cranial surgery under general anesthesia. According to the sleep duration on the night before surgery, patients were categorized into following four groups: <5, 5–7, 7–9, and >9 h. Perioperative cognitive function and domains were assessed using a neuropsychological test battery, and the incidence and prevalence of cognitive decline over 6 months after surgery were analyzed using the multiple logistic regression analysis. During the 6-month follow-up period, 41 patients (21%) developed cognitive decline. The incidence of cognitive decline was significantly elevated for the patients with sleep duration < 5 h (vs. 7–9 h; surgical duration-adjusted odds ratio, 3.50; 95% confidence interval, 1.20–10.2; P < 0.05). The association between sleep duration and prevalence of cognitive decline was limited to the early postoperative period (at 1 week and 1 month). Among the cognitive domains assessed, attentional function was significantly impaired in patients with a sleep duration < 5 h [vs. 7–9 h at 1 week; 4/37 (10.8%) vs. 0/73 (0%); P < 0.05]. In conclusion, sleep duration < 5 h on the night before surgery was significantly associated with worse attentional function after surgery and higher incidence of cognitive decline. The present results indicate that sleep deprivation on the night before surgery may have a temporary but significantly negative influence on the patient's postoperative cognitive function and is a potential target for preventing cognitive decline.

Predicting Delayed Neurocognitive Recovery After Non-cardiac Surgery Using Resting-State Brain Network Patterns Combined With Machine Learning

Delayed neurocognitive recovery (DNR) is a common subtype of postoperative neurocognitive disorders. An objective approach for identifying subjects at high risk of DNR is yet lacking. The present study aimed to predict DNR using the machine learning method based on multiple cognitive-related brain network features. A total of 74 elderly patients (≥ 60-years-old) undergoing non-cardiac surgery were subjected to resting-state functional magnetic resonance imaging (rs-fMRI) before the surgery. Seed-based whole-brain functional connectivity (FC) was analyzed with 18 regions of interest (ROIs) located in the default mode network (DMN), limbic network, salience network (SN), and central executive network (CEN). Multiple machine learning models (support vector machine, decision tree, and random forest) were constructed to recognize the DNR based on FC network features. The experiment has three parts, including performance comparison, feature screening, and parameter adjustment. Then, the model with the best predictive efficacy for DNR was identified. Finally, independent testing was conducted to validate the established predictive model. Compared to the non-DNR group, the DNR group exhibited aberrant whole-brain FC in seven ROIs, including the right posterior cingulate cortex, right medial prefrontal cortex, and left lateral parietal cortex in the DMN, the right insula in the SN, the left anterior prefrontal cortex in the CEN, and the left ventral hippocampus and left amygdala in the limbic network. The machine learning experimental results identified a random forest model combined with FC features of DMN and CEN as the best prediction model. The area under the curve was 0.958 (accuracy = 0.935, precision = 0.899, recall = 0.900, F1 = 0.890) on the test set. Thus, the current study indicated that the random forest machine learning model based on rs-FC features of DMN and CEN predicts the DNR following non-cardiac surgery, which could be beneficial to the early prevention of DNR. Clinical Trial Registration: The study was registered at the Chinese Clinical Trial Registry (Identification number: ChiCTR-DCD-15006096).