Does Postoperative Cognitive Decline Result in New Disability After Surgery?

The Association of Plasma Leptin, Soluble Leptin Receptor and Total and High-Molecular Weight Adiponectin With the Risk of Perioperative Neurocognitive Disorders

BACKGROUND

Perioperative neurocognitive disorders (NCD) are poorly characterized in terms of their risk factor profiles. Leptin and adiponectin are adipose-tissue-derived hormones with a role in inflammation and atherosclerosis whose function in perioperative NCD is unclear. Here, we used a cohort of older adults to examine the association of preoperative plasma concentrations of these biomarkers with the risk of perioperative NCD.

METHODS

Prospective analysis of 768 participants aged ≥ 65 years of the BioCog study. Blood was collected before surgery for measurement of plasma total and high-molecular-weight (hmw) adiponectin, leptin, and soluble leptin receptor (sOB-R). The free leptin index (FLI, leptin:sOB-R) was calculated. Postoperative delirium (POD) was assessed twice daily until postoperative day 7/discharge. Five hundred twenty-six patients (68.5%) returned for 3-month follow-up and provided data on postoperative cognitive dysfunction (POCD). POCD was defined as a decline on six neuropsychological tests that exceeded that of a nonsurgical control group. Logistic regression analyses examined the associations of each exposure with POD and POCD risk, in separate models adjusted for age, sex, fasting, surgery type, and body mass index (BMI).

RESULTS

Of 768 patients, 152 (19.8%) developed POD. Of 526 attendants of the follow-up, 54 (10.3%) had developed POCD. Leptin, sOB-R, and total and hmw adiponectin were each not associated with POD. For POCD, we observed reduced risk in patients in FLI quartile 4 compared with quartile 1 (odds ratio, 0.26; 95% CI 0.08, 0.89). Sensitivity analyses for the outcome POD revealed statistically significant interaction terms of sOB-R and total adiponectin with obesity (BMI≥30kg/m2 versus BMI<30kg/m2). For the outcome POCD, a higher sOB-R was associated with an increased risk in the obese subgroup (odds ratio, 4.00; 95% CI 1.01, 15.86).

CONCLUSIONS

We did not find consistent evidence for the role of leptin, its receptor, and total and hmw adiponectin in POD and POCD risk. Future research should be used to support or refute our findings and to fully characterize any differences in the associations of these hormones with POD/POCD between obese and nonobese individuals.

Top Ten Tips Palliative Care Clinicians Should Know Before Their Patient Undergoes Surgery?

Many seriously ill patients undergo surgical interventions. Palliative care clinicians may not be familiar with the nuances involved in perioperative care, however they can play a valuable role in enabling the delivery of patient-centered and goal-concordant perioperative care. The interval of time surrounding a surgical intervention is fraught with medical, psychosocial, and relational risks, many of which palliative care clinicians may be well-positioned to navigate. A perioperative palliative care consult may involve exploring gaps between clinician and patient expectations, facilitating continuity of symptom management or helping patients to designate a surrogate decision-maker before undergoing anesthesia. Palliative care clinicians may also be called upon to direct discussions around perioperative management of modified code status orders and to engage around the goal-concordance of proposed interventions. This article, written by a team of surgeons and anesthesiologists, many with subspecialty training in palliative medicine and/or ethics, offers ten tips to support palliative care clinicians and facilitate comprehensive discussion as they engage with patients and clinicians considering surgical interventions.

Outcomes associated with postoperative cognitive dysfunction: a systematic review and meta-analysis

BACKGROUND

Postoperative cognitive dysfunction (POCD) manifests as a subtle decline in cognition, potentially leading to unfavourable postoperative outcomes. We explored the impact of POCD on physical function, length of hospital stay (LOS), dementia and mortality outcomes.

METHODS

PubMed and Scopus were searched until May 2023. All studies of major surgical patients that assessed POCD and outcomes of interest were included. POCD effects were stratified by surgery type (cardiac and noncardiac) and time of POCD assessment (<30 and ≥30 days postsurgery).

RESULTS

Of 2316 studies, 20 met the inclusion criteria. POCD was not associated with functional decline postsurgery. Patients who experienced POCD postcardiac surgery had an increased relative risk (RR) of death of 2.04 [(95% CI: 1.18, 3.50); I2 = 0.00%]. Sensitivity analyses showed associations with intermediate-term mortality among noncardiac surgical patients, with an RR of 1.84 [(95% CI: 1.26, 2.71); I2 = 0.00%]. Patients who developed POCD <30 days postcardiac and noncardiac surgeries experienced longer LOS than those who did not [mean difference (MD) = 1.37 days (95% CI: 0.35, 2.39); I2 = 92.38% and MD = 1.94 days (95% CI: 0.48, 3.40); I2 = 83.29%, respectively]. Postoperative delirium (POD) may contribute to the heterogeneity observed, but limited data were reported within the studies included.

CONCLUSIONS

Patients undergoing cardiac and noncardiac surgeries who developed POCD <30 days postsurgery had poorer outcomes and an increased risk of premature death. Early recognition of perioperative neurocognitive disorders in at-risk patients may enable early intervention. However, POD may confound our findings, with further studies necessary to disentangle the effects of POD from POCD on clinical outcomes.

The impact of geriatric-specific variables on long-term outcomes in patients with hepatopancreatobiliary and colorectal cancer selected for resection

BACKGROUND

Preoperative geriatric-specific variables (GSV) influence short-term morbidity in surgical patients, but their impact on long-term survival in elderly patients with cancer remains undefined.

STUDY DESIGN

This observational cohort study included patients ≥65 years who underwent hepatopancreatobiliary or colorectal operations for malignancy between 2014 and 2020. Individual patient data included merged ACS NSQIP data, Procedure Targeted, and Geriatric Surgery Research variables. Patients were stratified by age: 65-74, 75-84, and ≥85 and presence of these GSVs: mobility aid, preoperative falls, surrogate signed consent, and living alone. Bivariable and multivariable analyses were used to evaluate 1-year mortality and postoperative discharge to facility.

RESULTS

577 patients were included: 62.6 % were 65-74 years old, 31.7 % 75-84, and 5.7 % ≥ 85. 96 patients were discharged to a facility with frequency increasing with age group (11.4 % vs 22.4 % vs 42.4 %, respectively, p < 0.001). 73 patients (12.7 %) died during 1-year follow-up, 32.9 % from cancer recurrence. One-year mortality was associated with undergoing hepatopancreatobiliary operations (p = 0.017), discharge to a facility (p = 0.047), and a surrogate signing consent (p = 0.035). Increasing age (p < 0.001), hepatopancreatobiliary resection (p = 0.002), living home alone (p < 0.001), and mobility aid use (p < 0.001) were associated with discharge to a facility.

CONCLUSION

Geriatric-specific variables, living alone and use of a mobility aid, were associated with discharge to a facility. A surrogate signing consent and discharge to a facility were associated with 1-year mortality. These findings underscore the importance of preoperative patient selection and optimization, efficacious discharge planning, and informed decision-making in the care of elderly cancer patients.

Surgery induces neurocognitive disorder via neuroinflammation and glymphatic dysfunction in middle-aged mice with brain lymphatic drainage impairment

Background

Brain lymphatic drainage impairment is a prevalent characteristic in both aging and neurodegeneration. Surgery is more likely to induce excessive neuroinflammation and postoperative neurocognitive disorder (PND) among patients with aging and neurodegeneration. We hypothesized that surgical trauma may aggravate PND through preexisting cerebral lymphatic drainage impairment. However, there remains limited understanding about the role of surgery in changes of neurocognitive function in the populations with preoperative brain lymphatic drainage impairment. This study aims to expand our insight into surgery-induced glymphatic dysfunction, neuroinflammation and PND in middle-aged mice with preoperative brain lymphatic drainage impairment.

Materials and methods

Deep cervical lymph nodes ligation (LdcLNs) was performed on middle-aged mice to establish preoperative brain lymphatic drainage impairment. A month later, laparotomy was performed on these mice with or without LdcLNs followed by analysis of brain neuroinflammation, glymphatic function, neuronal damage, and behavioral test.

Results

LdcLNs disrupted meningeal lymphatic drainage. In middle-aged mice with LdcLNs, surgery exacerbated more serious glymphatic dysfunction accompanied by aggravation of A1 astrocytes activation and AQP4 depolarization. Furthermore, surgery caused neuronal damage via reducing expression of neuronal nuclei (NeuN), post-synaptic density protein 95 (PSD95) and synaptophysin (SYP), as well as impairment in exploratory behavior and spatial working memory in middle-aged mice with LdcLNs. Additionally, surgery induced neuroinflammation with elevated microglia activation and increased the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6, as well as activated more expression of HMGB1/TLR-4/NF-κB pathway in middle-aged mice with LdcLNs.

Conclusion

Surgery exacerbates neuroinflammation and glymphatic dysfunction, ultimately resulting in neuronal damage and neurocognitive disorder in middle-aged mice with preoperative brain lymphatic drainage impairment. These results suggest that brain lymphatic drainage impairment may be a deteriorating factor in the progression of PND, and restoring its function may serve as a potential strategy against PND.

Serum proteomics study on cognitive impairment after cardiac valve replacement surgery: a prospective observational study

Objective

The incidence of perioperative neurocognitive disorders (PND) is high, especially after cardiac surgeries, and the underlying mechanisms remain elusive. Here, we conducted a prospective observational study to observe serum proteomics differences in PND patients after cardiac valve replacement surgery.

Methods

Two hundred and twenty-six patients who underwent cardiac valve surgery were included. They were categorized based on scoring into non-PND group (group non-P) and PND group (group P'). The risk factors associated with PND were analyzed. These patients were further divided into group C and group P by propensity score matching (PSM) to investigate the serum proteome related to the PND by serum proteomics.

Results

The postoperative 6-week incidence of PND was 16.8%. Risk factors for PND include age, chronic illness, sufentanil dosage, and time of cardiopulmonary bypass (CPB). Proteomics identified 31 down-regulated proteins and six up-regulated proteins. Finally, GSTO1, IDH1, CAT, and PFN1 were found to be associated with PND.

Conclusion

The occurrence of PND can impact some oxidative stress proteins. This study provided data for future studies about PND to general anaesthesia and surgeries.

The influence of sleep disorders on perioperative neurocognitive disorders among the elderly: A narrative review

This review comprehensively assesses the epidemiology, interaction, and impact on patient outcomes of perioperative sleep disorders (SD) and perioperative neurocognitive disorders (PND) in the elderly. The incidence of SD and PND during the perioperative period in older adults is alarmingly high, with SD significantly contributing to the occurrence of postoperative delirium. However, the clinical evidence linking SD to PND remains insufficient, despite substantial preclinical data. Therefore, this study focuses on the underlying mechanisms between SD and PND, underscoring that potential mechanisms driving SD-induced PND include uncontrolled central nervous inflammation, blood-brain barrier disruption, circadian rhythm disturbances, glial cell dysfunction, neuronal and synaptic abnormalities, impaired central metabolic waste clearance, gut microbiome dysbiosis, hippocampal oxidative stress, and altered brain network connectivity. Additionally, the review also evaluates the effectiveness of various sleep interventions, both pharmacological and nonpharmacological, in mitigating PND. Strategies such as earplugs, eye masks, restoring circadian rhythms, physical exercise, noninvasive brain stimulation, dexmedetomidine, and melatonin receptor agonists have shown efficacy in reducing PND incidence. The impact of other sleep-improvement drugs (e.g., orexin receptor antagonists) and methods (e.g., cognitive-behavioral therapy for insomnia) on PND is still unclear. However, certain drugs used for treating SD (e.g., antidepressants and first-generation antihistamines) may potentially aggravate PND. By providing valuable insights and references, this review aimed to enhance the understanding and management of PND in older adults based on SD.

Advancing Perioperative Neurocognitive Health: A Critical Review of Predictive Tools, Diagnostic Methods, and Interventional Strategies

Perioperative neurocognitive disorders (PNDs) affect a large percentage of people who undergo surgeries that need general anesthesia. There is an increased risk of death and a major disruption to postoperative self-care as a result of this. This study compiles all the relevant materials that the authors have found to investigate postnatal depression and its causes, as well as the methods used to determine the probability and severity of PNDs and how to reduce their risk before surgery. Postnatal depression can have many causes, and this text explores some of them. These include a history of alcohol or opiate use, immunological dysregulation, advanced age, educational background, infections, neurocognitive impairment, and pre-existing chronic inflammatory disorders. It also delves into various methods used to gauge the likelihood and severity of postpartum depression. The following assessment tools were covered: the Clock Drawing Test, Domain-Specific Tests, the Mini-Mental State Examination, and the Montreal Cognitive Assessment. In addition to biochemical markers, neuroimaging techniques play an important role in diagnosis. The Frailty Fried assessment, which measures inertia, sluggishness, lack of physical activity, fatigue, and unintentional weight loss, is a key prognostic sign that is highlighted. There is strong evidence that the index, which is derived from these five characteristics, may accurately predict the likelihood of PNDs. Risk mitigation strategies are also covered in this research. Preoperative brain plasticity-based therapies, such as physical exercise and intensive cognitive training, can significantly reduce the incidence and severity of postoperative neurocognitive disorders. A peripheral nerve block, monitoring cerebral oxygen saturation, dexmedetomidine, and a reduction in anesthesia depth are all ways to improve anesthetic procedures. Methods that lower blood pressure should be avoided, the body temperature should be kept down during surgery, or the time without liquids should be lengthened; all of these raise the risk of postoperative nausea and vomiting and make it worse. Potential approaches include a Mediterranean diet, physical activity, cognitive stimulation, smoking cessation, alcohol reduction, avoidance of anticholinergic medications, and non-steroidal anti-inflammatory drug stewardship, although there is no definitive evidence for successful postoperative neurocognitive rehabilitation procedures. More standardized diagnostic criteria, evaluation methods, and PND classification are urgently needed, according to this study. Different cases of PNDs are characterized by different combinations of tests, cutoff values, and methods because there is a broad variety of diagnostic tests used to make the diagnosis. Until now, PNDs and pre-existing neurocognitive disorders have been diagnosed using the Diagnostic and Statistical Manual of Mental Disorders (DSM-V). With an aging population comes an increase in the occurrence and prevalence of PNDs, which calls for a specific way to classify and describe the condition.

Perioperative Considerations in Older Kidney and Liver Transplant Recipients: A Review

With the growth of the older adult population, the number of older adults waitlisted for and undergoing kidney and liver transplantation has increased. Transplantation is an important and definitive treatment for this population. We present a contemporary review of the unique preoperative, intraoperative, and postoperative issues that patients older than 65 y face when they undergo kidney or liver transplantation. We focus on geriatric syndromes that are common in older patients listed for kidney or liver transplantation including frailty, sarcopenia, and cognitive dysfunction; discuss important considerations for older transplant recipients, which may impact preoperative risk stratification; and describe unique challenges in intraoperative and postoperative management for older patients. Intraoperative challenges in the older adult include using evidence-based best anesthetic practices, maintaining adequate perfusion pressure, and using minimally invasive surgical techniques. Postoperative concerns include controlling acute postoperative pain; preventing cardiovascular complications and delirium; optimizing immunosuppression; preventing perioperative kidney injury; and avoiding nephrotoxicity and rehabilitation. Future studies are needed throughout the perioperative period to identify interventions that will improve patients' preoperative physiologic status, prevent postoperative medical complications, and improve medical and patient-centered outcomes in this vulnerable patient population.

Risk Factors for Postoperative Cognitive Decline After Orthopedic Surgery in Elderly Chinese Patients: A Retrospective Cohort Study

Purpose

We aimed to identify the risk factors for postoperative cognitive decline (POCD) by evaluating the outcomes from preoperative comprehensive geriatric assessment (CGA) and intraoperative anesthetic interventions.

Patients and Methods

Data used in the study were obtained from the Aged Patient Perioperative Longitudinal Evaluation-Multidisciplinary Trial (APPLE-MDT) cohort recruited from the Department of Orthopedics in Xuanwu Hospital, Capital Medical University between March, 2019 and June, 2022. All patients accepted preoperative CGA by the multidisciplinary team using 13 common scales across 15 domains reflecting the multi-organ functions. The variables included demographic data, scales in CGA, comorbidities, laboratory tests and intraoperative anesthetic data. Cognitive function was assessed by Montreal Cognitive Assessment scale within 48 hours after admission and after surgery. Dropping of ≥1 point between the preoperative and postoperative scale was defined as POCD.

Results

We enrolled 119 patients. The median age was 80.00 years [IQR, 77.00, 82.00] and 68 patients (57.1%) were female. Forty-two patients (35.3%) developed POCD. Three cognitive domains including calculation (P = 0.046), recall (P = 0.047) and attention (P = 0.007) were significantly worsened after surgery. Univariate analysis showed that disability of instrumental activity of daily living, incidence rate of postoperative respiratory failure (PRF) ≥4.2%, STOP-Bang scale score, Caprini risk scale score and Sufentanil for maintenance of anesthesia were different between the POCD and non-POCD patients. In the multivariable logistic regression analysis, PRF ≥ 4.2% (odds ratio [OR] = 2.343; 95% confidence interval [CI]: 1.028-5.551; P = 0.046) and Sufentanil for maintenance of anesthesia (OR = 0.260; 95% CI: 0.057-0.859; P = 0.044) was independently associated with POCD as risk and protective factors, respectively.

Conclusion

Our study suggests that POCD is frequent among older patients undergoing elective orthopedic surgery, in which decline of calculation, recall and attention was predominant. Preoperative comprehensive geriatric assessments are important to identify the high-risk individuals of POCD.

Clinical Outcomes After Traumatic Brain Injury and Exposure to Extracranial Surgery: A TRACK-TBI Study

Importance

Traumatic brain injury (TBI) is associated with persistent functional and cognitive deficits, which may be susceptible to secondary insults. The implications of exposure to surgery and anesthesia after TBI warrant investigation, given that surgery has been associated with neurocognitive disorders.

Objective

To examine whether exposure to extracranial (EC) surgery and anesthesia is related to worse functional and cognitive outcomes after TBI.

Design, Setting, and Participants

This study was a retrospective, secondary analysis of data from the Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) study, a prospective cohort study that assessed longitudinal outcomes of participants enrolled at 18 level I US trauma centers between February 1, 2014, and August 31, 2018. Participants were 17 years or older, presented within 24 hours of trauma, were admitted to an inpatient unit from the emergency department, had known Glasgow Coma Scale (GCS) and head computed tomography (CT) status, and did not undergo cranial surgery. This analysis was conducted between January 2, 2020, and August 8, 2023.

Exposure

Participants who underwent EC surgery during the index admission were compared with participants with no surgery in groups with a peripheral orthopedic injury or a TBI and were classified as having uncomplicated mild TBI (GCS score of 13-15 and negative CT results [CT- mTBI]), complicated mild TBI (GCS score of 13-15 and positive CT results [CT+ mTBI]), or moderate to severe TBI (GCS score of 3-12 [m/sTBI]).

Main Outcomes and Measures

The primary outcomes were functional limitations quantified by the Glasgow Outcome Scale-Extended for all injuries (GOSE-ALL) and brain injury (GOSE-TBI) and neurocognitive outcomes at 2 weeks and 6 months after injury.

Results

A total of 1835 participants (mean [SD] age, 42.2 [17.8] years; 1279 [70%] male; 299 Black, 1412 White, and 96 other) were analyzed, including 1349 nonsurgical participants and 486 participants undergoing EC surgery. The participants undergoing EC surgery across all TBI severities had significantly worse GOSE-ALL scores at 2 weeks and 6 months compared with their nonsurgical counterparts. At 6 months after injury, m/sTBI and CT+ mTBI participants who underwent EC surgery had significantly worse GOSE-TBI scores (B = -1.11 [95% CI, -1.53 to -0.68] in participants with m/sTBI and -0.39 [95% CI, -0.77 to -0.01] in participants with CT+ mTBI) and performed worse on the Trail Making Test Part B (B = 30.1 [95% CI, 11.9-48.2] in participants with m/sTBI and 26.3 [95% CI, 11.3-41.2] in participants with CT+ mTBI).

Conclusions and Relevance

This study found that exposure to EC surgery and anesthesia was associated with adverse functional outcomes and impaired executive function after TBI. This unfavorable association warrants further investigation of the potential mechanisms and clinical implications that could inform decisions regarding the timing of surgical interventions in patients after TBI.

Comparing analog and digital neurocognitive tests with older adults: a study of the ISPOCD battery vs. a digital test battery from Mindmore

BACKGROUND

Delayed neurocognitive recovery and neurocognitive disorder are common postoperative complications among older adults. The assessment of these complications traditionally relies on analog neurocognitive tests, predominantly using the test battery from the ISPOCD-study as the standard approach. However, analog tests are time-consuming and necessitate trained staff which poses limitations. The potential availability of a digital neurocognitive test as an alternative to the ISPOCD remains unknown. We conducted a comparative study between the analog test battery from ISPOCD and the self-administrated digital test battery developed by Mindmore.

METHODS

We conducted a crossover study with 50 cognitively healthy older adults ≥ 60 years of age recruited in Stockholm Sweden, between February and April 2022. The primary outcome focused on measuring comparability between the two test batteries. Our secondary outcomes included assessing participants' perceptions and attitudes about the tests with qualitative interviews and their usability experiences.

RESULTS

Fifty older adults, mean age 76, female 56%, with a university or college degree 48% participated in the study. The sub tests in two test batteries demonstrated a medium-large correlation (r = 0.3-0.5), except for one measure. For four out of six measures, significant differences were found with medium to large effect sizes, ranging from 0.57-1.43. Two categories were recognized in the qualitative analysis: self-competing in a safe environment, and experience with technology. Participants expressed feeling safe and at ease during the assessment, with some preferring the digital test over the analog. Participants reported a high level of usability with the digital test and a majority participants (n = 47) reported they would undergo the digital test for a potential future surgery.

CONCLUSIONS

The digital test battery developed by Mindmore offers several advantages, including rapid access to test results, easy comprehension, and use for participants, thereby increased accessibility of cognitive screening.

TRIAL REGISTRATION NUMBER

NCT05253612; ClinicalTrials.gov, 24/02/2022.

M1-Type Microglia-Derived Extracellular Vesicles Overexpressing IL-1R1 Promote Postoperative Cognitive Dysfunction by Regulating Neuronal Inflammation

Postoperative cognitive dysfunction (POCD) is a common complication after surgical anesthesia, mainly manifested as memory impairment, decreased attention, and cognitive function with mood and personality changes. Activated microglia (M1-type microglia) have been demonstrated to release inflammatory substances (IL-1β, TNF-α, etc.) that cause neuronal degeneration and death by activating the NF-κB signaling pathway and upregulating Caspase-3 and Bax. However, the pathogenesis of POCD is still not fully understood and needs further research. In the present study, we investigated the effect of M1-type microglia-derived extracellular vesicles (EVsM1-Microglia) in the pathological process of POCD. The levels of NF-κB phosphorylation and IL-1β protein expression in hippocampal neurons were significantly increased in the Surgery group, while PSD95 and MAP2 were significantly decreased. Surgery induced microglia activation, synapse-associated protein decrease, and neuronal degeneration in hippocampus. And the amount of spine and mushroom spine significantly decreased in surgical mice, which was reverted in the presence of IL-1R1 siRNA. In addition, EVsM1-Microglia promoted synaptic loss and neuron degeneration independent of surgery and microglia activation. Furthermore, EVsM1-Microglia promoted memory defects in surgical mice. We demonstrated that EVsM1-Microglia with high expression of IL-1R1 promote POCD development by regulating neuronal inflammation.

Inhibition of adult hippocampal neurogenesis induced by postoperative CD8 + T-cell infiltration is associated with cognitive decline later following surgery in adult mice

BACKGROUND

Some patients show persistent cognitive decline for weeks, months or even years after surgery, which seriously affects their long-term prognosis and quality of life. However, most previous basic studies have focused mainly on the mechanisms of early postoperative cognitive decline, whereas cognitive decline in the longer term after surgery is less well-understood. The subgranular zone of the dentate gyrus exhibits life-long neurogenesis, supporting hippocampus-dependent learning and memory.

MAIN TEXT

The aim of this study was to investigate whether adult hippocampal neurogenesis (AHN) involves in cognitive decline later following surgery and to further explore the roles of CD8 + T lymphocytes infiltrating the hippocampal parenchyma after surgery in this pathological process. Cognitive function was examined in adult mice that underwent laparotomy combined with partial hepatectomy, and the results showed that cognitive decline persisted in mice who underwent surgery during the first postoperative month, even though there was a trend toward continuous improvement over time. Significantly decreased numbers of DCX + cells, BrdU + cells, and BrdU + /DCX + cells were observed on day 8 after surgery, and a significantly decreased number of NeuN + /BrdU + cells was observed on day 28 after surgery, which indicated inhibition of AHN. After surgery, T lymphocytes, the majority of which were CD8 + T cells, infiltrated the hippocampus and secreted Interferon-γ (IFN-γ). Depletion of CD8 + T cells could inhibit the increase of IFN-γ synthesis, improve hippocampal neurogenesis, and improve postoperative cognitive function. Hippocampal microinjection of IFN-γ neutralizing antibody or adeno-associated virus to knock down IFN-γ receptor 1 (IFNGR1) could also partially attenuate the inhibition of AHN and improve postoperative cognitive function.

CONCLUSIONS

These results demonstrate that postoperative infiltration of CD8 + T cells into the hippocampus and subsequent secretion of IFN-γ contribute to the inhibition of AHN and cognitive decline later following surgery.

Effect of transcutaneous electrical acupoint stimulation on postoperative cognitive function in older patients with lung cancer: A randomized, double-blind, placebo-controlled trial

Objective

This trial was to examine the effect of transcutaneous electrical acupoint stimulation (TEAS) on postoperative cognitive function in older patients who underwent thoracoscopic pulmonary resection.

Methods

This was a prospective, randomized, double-blind, placebo-controlled study. 128 patients scheduled for surgery were randomly assigned to the TEAS group and sham-TEAS group. A standardized intervention of TEAS or sham-TEAS on the acupoints of Baihui (DU20) and bilateral Neiguan (PC6), Hegu (LI4), and Zusanli (ST36) from 30 min before anesthesia induction until the end of the surgery, combined with a general anesthetic protocol performed in the two groups respectively. The primary outcome was the incidence of postoperative cognitive dysfunction (POCD) assessed via the Montreal Cognitive Assessment (MoCA) scale at each time point. The secondary outcomes included the results of the Mini-Mental State Examination (MMSE) score, the Numerical Rating Scale (NRS) on pain and sleep, the European Organization for Research and Treatment of Cancer Quality of Life (EORTC-QLQ-C30), and a chronic pain questionnaire at relative time points.

Results

Participants who completed the 12-month trial of the two groups were well-matched in baseline demographic and clinical parameters. At postoperative day 1, day 7, and day 30 time points, the incidence of POCD in the sham-TEAS group was always significantly higher than in the TEAS group (65.4% vs 20%, 43.6% vs 7.3%, 40% vs 3.6%, all P < 0.001). Also, the TEAS group showed better scores of MMSE, sleep, and pain compared with the sham-TEAS group (all P < 0.001). At 6 and 12 months points, the global health scores of the TEAS group were still significantly higher than the sham-TEAS group, and the prevalence of chronic pain was significantly lower than the sham-TEAS group (all P < 0.05).

Conclusion

TEAS could effectively improve the postoperative cognitive function and long-term life quality of geriatric patients with lung cancer.

High preoperative blood oxaloacetate and 2-aminoadipic acid levels are associated with postoperative delayed neurocognitive recovery

Introduction

This study aimed to identify preoperative blood biomarkers related to development of delayed neurocognitive recovery (dNCR) following surgery.

Methods

A total of 67 patients (≥65 years old) who underwent head and neck tumor resection under general anesthesia were assessed using the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA). Preoperative serum metabolomics were determined using widely targeted metabolomics technology.

Results

Of the 67 patients, 25 developed dNCR and were matched to 25 randomly selected patients from the remaining 42 without dNCR. Differential metabolites were selected using the criteria of variable importance in projection > 1.0 in orthogonal partial least squares discrimination analysis, false discovery rate <0.05, and fold-change >1.2 or <0.83 to minimize false positives. Preoperative serum levels of oxaloacetate (OR: 1.054, 95% CI: 1.027-1.095, P = 0.001) and 2-aminoadipic acid (2-AAA) (OR: 1.181, 95% CI: 1.087-1.334, P = 0.001) were associated with postoperative dNCR after adjusting for anesthesia duration, education, and age. Areas under the curve for oxaloacetate and 2-AAA were 0.86 (sensitivity: 0.84, specificity: 0.88) and 0.86 (sensitivity: 0.84, specificity: 0.84), respectively. High levels of preoperative oxaloacetate and 2-AAA also were associated with postoperative decreased MoCA (β: 0.022, 95% CI: 0.005-0.04, P = 0.013 for oxaloacetate; β: 0.077, 95%CI: 0.016-0.137, P = 0.014 for 2-AAA) and MMSE (β: 0.024, 95% CI: 0.009-0.039, P = 0.002 for oxaloacetate; β: 0.083, 95% CI: 0.032-0.135, P = 0.002 for 2-AAA) scores after adjusting for age, education level, and operation time.

Conclusion

High preoperative blood levels of oxaloacetate and 2-AAA were associated with increased risk of postoperative dNCR.

Clinical trial registration

https://classic.clinicaltrials.gov/ct2/show/NCT05105451, identifier NCT05105451.

Effect of internal jugular vein catheterization on intracranial pressure and postoperative cognitive function in patients undergoing robot-assisted laparoscopic surgery

Background

We aimed to evaluate the effects of internal jugular vein (IJV) catheterization on intracranial pressure (ICP) and postoperative delirium (POD) during robot-assisted laparoscopic surgery by measuring the optic nerve sheath diameter (ONSD).

Methods

Data from a prospective single-center cohort study, conducted from October 2021 to February 2022, were used. Forty out of 80 patients scheduled for laparoscopic radical hysterectomy or prostatectomy were assigned to the group receiving IJV catheterization (Group I), and the other 40 only received peripheral venous cannulation (Group C) according to clinical need of patients. Ultrasonography of ONSDs, the proportion of regurgitation time in a cardiac cycle, and hemodynamic parameters were measured at four time points: immediately after induction of anesthesia in the supine position (T0), 30 min (T1), 60 min (T2) after orienting to the Trendelenburg position, and before returning to the supine position at the end of surgery (T3). Time to eye opening and emergence stay, POD, and QoR-15 were compared.

Results

The ONSDs increase gradually as the surgery progressed. Group I showed a higher value of ONSD at T1 (4.72 ± 0.29 mm vs. 4.5 ± 0.33 mm, p = 0.0057) and T3 (5.65 ± 0.33 mm vs. 5.26 ± 0.31 mm, p < 0.0001). The proportions of the regurgitation time of IJVV were greater in Group I than those in Group C at T1 (14.95, 8.5%-18.9% vs. 9.6%, 0%-17.2%, p < 0.0001) and T3 (14.3, 10.6%-18.5% vs. 10.4%, 0%-16.5%, p = 0.0003). Group I had a delayed time to eye opening (10.7 ± 1.72 min vs. 13.3 ± 2.35 min, p < 0.0001) and emergence stay (32.2 ± 5.62 min vs. 39.9 ± 6.7 min, p < 0.0001). There were no significant differences in POD and QoR-15 between the two groups on day three.

Conclusion

IJV cannulation may not be the preferred approach in robot-assisted laparoscopic surgery as it was risk factor for IJVV regurgitation, ICP elevation, emergence delayed.

Gα13-Mediated Signaling Cascade Is Related to the Tau Pathology Caused by Anesthesia and Surgery in 5XFAD Transgenic Mice

BACKGROUND

Our previous studies indicated that anesthesia and surgery could aggravate cognitive impairment of 5XFAD transgenic (Tg) mice, and this aggravation was associated with tau hyperphosphorylation. We previously identified that GNA13 (the gene encoding Gα13) was a hub gene with tau hyperphosphorylation.

OBJECTIVE

This study aims to further investigate the mechanism that whether the Gα13-mediated signaling pathway acts as an instigator to regulate cofilin activation and autophagy impairment in this process.

METHODS

5XFAD Tg mice and their littermate (LM) mice were randomly allocated into four groups: LM Control group, LM Anesthesia/Surgery group, AD Control group, and AD Anesthesia/Surgery group. For mice in the Anesthesia/Surgery groups, abdominal surgery was performed under 1.4% isoflurane anesthesia followed by sustaining anesthetic inhalation for up to 2 h.

RESULTS

Compared with the AD Control group, protein levels of Gα13, ROCK2, LPAR5, and p-tau/tau46 ratio were increased, while p-cofilin/cofilin protein expression ratio was decreased in the AD Anesthesia/Surgery group. However, the differences in these protein levels were not significant among LM groups.

CONCLUSION

This study demonstrated that anesthesia and surgery might exacerbate p-tau accumulation in 5XFAD Tg mice but not in LM mice. And this might be closely related to cofilin activation via Gα13-mediated signaling cascade.

Risk factors for delayed neurocognitive recovery in elderly patients undergoing thoracic surgery

BACKGROUND

To investigate the risk factors for delayed neurocognitive recovery in elderly patients undergoing thoracic surgery.

METHODS

A total of 215 elderly patients who underwent thoracic surgery between May 2022 and October 2022 were recruited in this prospective observational study. Cognitive function was tested by MoCA tests that were performed by the same trained physician before surgery, on postoperative day 4 (POD4), and on postoperative day 30 (POD30). Univariate and multivariate logistic regression models were used to analyze the risk factors for DNR.

RESULTS

A total of 154 patients (55.8% men) with an average age of 67.99 ± 3.88 years were finally included. Patients had an average preoperative MoCA score of 24.68 ± 2.75. On the 30th day after surgery, 26 (16.88%) patients had delayed postoperative cognitive recovery, and 128 (83.12%) had postoperative cognitive function recovery. Diabetes mellitus (OR = 6.508 [2.049-20.664], P = 0.001), perioperative inadvertent hypothermia (< 35℃) (OR = 5.688 [1.693-19.109], P = 0.005), history of cerebrovascular events (OR = 10.211 [2.842-36.688], P < 0.001), and VICA (sevoflurane combined with propofol anesthesia) (OR = 5.306 [1.272-22.138], P = 0.022) resulted as independent risk factors of delayed neurocognitive recovery. On the POD4, DNR was found in 61 cases (39.6%), and age ≥ 70 years (OR = 2.311 [1.096-4.876], P = 0.028) and preoperative NLR ≥ 2.5 (OR = 0.428 [0.188-0.975], P = 0.043) were identified as independent risk factors.

CONCLUSIONS

The risk factors for delayed neurocognitive recovery in elderly patients undergoing thoracic surgery include diabetes, perioperative inadvertent hypothermia (< 35℃), VICA (sevoflurane combined with propofol anesthesia), and history of cerebrovascular events.

METTL3 relieved the injury of SH-SY5Y cells treated with lipopolysaccharide and exposed to sevoflurane through regulating the m6A levels of Sox2

INTRODUCTION

Postoperative cognitive dysfunction (POCD) is a common complication of the central nervous system in elderly patients. The objective of this study was to investigate the role of methyltransferase 3 (METTL3) in the POCD progression.

METHODS

The SH-SY5Y cells were treated with lipopolysaccharide (LPS) and exposed to sevoflurane to establish a POCD cell model. The cell viability and proliferation were assessed with MTT and EdU assays. Besides, the cell apoptosis was determined with TUNEL staining and flow cytometry. Additionally, the inflammatory factors were measured with ELISA. N6-methyladenosine (m6A) RNA Methylation Quantification Kit was used to detect the m6A levels. The relative expressions of methyltransferase 3 (METTL3) and Sex-determining region Y-box-2 (Sox2) was measured with RT-qPCR and western blot assays. RNA methylation immunoprecipitation-real-time quantitative PCR was performed to detect the RNA that was m6A modified.

RESULTS

After LPS treatment and sevoflurane exposure, the cell viability and proliferation were decreased and the cell apoptosis was elevated. The m6A and the METTL3 expression levels in the POCD cell model were declined. METTL3 overexpression promoted the cell growth and inhibited the cell apoptosis in the POCD cell model. Besides, the Sox2 levels were reduced in the POCD cell model. METTL3 silencing declined the m6A and mRNA levels of Sox2, while overexpression of METTL3 elevated it. The relationship between METTL3 and Sox2 was confirmed with double luciferase assay. Finally, Sox2 silencing neutralized the role of METTTL3 overexpression in the POCD cell model.

CONCLUSION

METTL3 relieved the injury of the SH-SY5Y cells induced by LPS treatment and sevoflurane exposure through regulating the m6A and mRNA levels of Sox2.

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

BACKGROUND

Postoperative cognitive dysfunction (POCD) is common after surgery and anesthesia, particularly in older patients. It has been reported that regional cerebral oxygen saturation (rSO₂) monitoring potentially influences the occurrence of POCD. However, its role in the prevention of POCD remains controversial in older patients. Additionally, the quality of evidence on this topic is still relatively poor.

METHODS

The electronic databases PubMed, EMBASE, Web of Science, and Cochrane Library were systematically searched using the indicated keywords from their inception to June 10, 2022. We limited our meta-analysis to randomized controlled trials (RCTs) that assessed the effects of rSO₂ monitoring on POCD in older patients. Methodological quality and risk of bias were assessed. The primary outcome was the incidence of POCD during hospitalization. The secondary outcomes were postoperative complications and the length of hospital stay (LOS). Odds ratios (OR) and 95% confidence intervals (CI) were calculated to determine the incidence of POCD and postoperative complications. The standardized mean difference (SMD) instead of the raw mean difference and 95% CI were calculated for LOS.

RESULTS

Six RCTs, involving 377 older patients, were included in this meta-analysis. The incidence of POCD ranges from 17 to 89%, with an overall prevalence of 47% in our pooled analysis. Our results demonstrated that rSO₂-guided intervention could reduce the incidence of POCD in older patients undergoing non-cardiac surgery (OR, 0.44; 95% CI, 0.25 to 0.79; P = 0.006) rather than cardiac surgery (OR, 0.69; 95% CI, 0.32 to 1.52; P = 0.36). Intraoperative rSO₂ monitoring was also associated with a significantly shorter LOS in older patients undergoing non-cardiac surgery (SMD, -0.93; 95% CI, -1.75 to -0.11; P = 0.03). Neither the incidence of postoperative cardiovascular (OR, 1.12; 95% CI, 0.40 to 3.17; P = 0.83) nor surgical (OR, 0.78; 95% CI, 0.35 to 1.75; P = 0.54) complications were affected by the use of rSO₂ monitoring.

CONCLUSION

The use of rSO₂ monitoring is associated with a lower risk of POCD and a shorter LOS in older patients undergoing non-cardiac surgery. This may have the potential to prevent POCD in high-risk populations. Further large RCTs are still warranted to support these preliminary findings.

Preoperative frailty risk in deep brain stimulation patients: Risk analysis index predicts Clavien-Dindo IV complications

OBJECTIVE

Deep brain stimulation (DBS) improves patients' quality of life in multiple movement disorders and chronic neurodegenerative diseases. There are no published studies assessing frailty's impact on DBS outcomes. We evaluated frailty's impacts on DBS outcomes, comparing discriminative thresholds of the risk analysis index (RAI) to modified frailty index-5 (mFI-5) for predicting Clavien-Dindo complications (CDIV).

METHODS

Patients who underwent DBS between 2015 and 2019 in the ACS-NSQIP registry were included. We employed receiver operating characteristic (ROC) curve to examine the discriminative thresholds of RAI and mFI-5 and multivariable analyses for postoperative outcomes. Our primary outcome was CDIV, and secondary outcomes were discharge to higher-level care facility, unplanned reoperation within 30 days, in any hospital, for any procedure related to the index procedure, and extended length of stay.

RESULTS

A total of 3795 patients were included. In the ROC analysis for CDIV, RAI showed superior discriminative threshold (C-statistic = 0.70, 95% CI 0.61-0.80, <0.001) than mFI-5 (C-statistic = 0.60, 95% CI 0.49-0.70, P = 0.08). On multivariable analyses, frailty stratified by RAI, had independent associations with CDIV, i.e., pre-frail 2-fold increase OR 2.04 (95% CI: 1.94-2.14) p < 0.001, and frail 39% increase OR 1.39 (95% CI: 1.27-1.53), p < 0.001.

CONCLUSION

Frailty was an independent risk-factor for CDIV. The RAI had superior discriminative thresholds than mFI-5 in predicting CDIV after DBS. Our ability to identify frail patients prior to DBS presents a novel clinical opportunity for quality improvement strategies to target this specific patient population. RAI may be a useful primary frailty screening modality for potential DBS candidates.

Isoflurane impairs GluN2B-containing NMDA receptors trafficking and cognition via decreasing histone acetylation and EphB2 expression in aged hippocampal neurons

Perioperative neurocognitive disorders (PND) is a common complication that occurs among elderly patients in the perioperative course. Current clinical evidence has shown that isoflurane exposure could cause cognitive decline, but the exact molecular mechanisms remain unclear. As both NMDARs-dependent synaptic plasticity and histone acetylation play vital roles in processing learning and memory, we postulated that these alternations might occur in the isoflurane-associated PND. Here, we found that isoflurane impaired fear memory in aged mice, decreased GluN2B-containing NMDA receptors phosphorylation and trafficking, as well as the expression of EphB2, a key regulator of synaptic localization of NMDA receptors. We also identified that isoflurane could increase the expression of HDAC2, which was significantly enriched at the ephb2 gene promoter and regulated the transcription of ephb2. Furthermore, we showed that suberoylanilide hydroxamic acid (SAHA), a nonselective HDAC inhibitor or knocking-down HDAC2 rescued the cognitive dysfunction in isoflurane-treated aged mice via increasing acetylation of H3Ac, expression of EphB2 and promoting NMDA receptor trafficking. Collectively, our study highlighted the crucial role of histone posttranslational modifications for EphB2-GluN2B signals in isoflurane-associated PND, and modulating HDAC2 might be a new therapeutic strategy for isoflurane-associated PND.

Age-Related Perioperative Neurocognitive Disorders: Experimental Models and Druggable Targets

With the worldwide increase in life span, surgical patients are becoming older and have a greater propensity for postoperative cognitive impairment, either new onset or through deterioration of an existing condition; in both conditions, knowledge of the patient's preoperative cognitive function and postoperative cognitive trajectory is imperative. We describe the clinical utility of a tablet-based technique for rapid assessment of the memory and attentiveness domains required for executive function. The pathogenic mechanisms for perioperative neurocognitive disorders have been investigated in animal models in which excessive and/or prolonged postoperative neuroinflammation has emerged as a likely contender. The cellular and molecular species involved in postoperative neuroinflammation are the putative targets for future therapeutic interventions that are efficacious and do not interfere with the surgical patient's healing process.

Perioperative probiotics attenuates postoperative cognitive dysfunction in elderly patients undergoing hip or knee arthroplasty: A randomized, double-blind, and placebo-controlled trial

Background

Postoperative cognitive dysfunction (POCD) is a common complication in elderly patients following surgery. The preventive and/or treatment strategies for the incidence remain limited.

Objective

This study aimed to investigate the preventive effect of perioperative probiotic treatment on POCD in elderly patients undergoing hip or knee arthroplasty.

Methods

After obtaining ethical approval and written informed consent, 106 patients (age ≥60 years) were recruited, who scheduled elective hip or knee arthroplasty, from 16 March 2021 to 25 February 2022 for this randomized, double-blind, and placebo-controlled trial. They were randomly assigned with a 1:1 ratio to receive either probiotics or placebo treatment (four capsules, twice/day) from hospital admission until discharge. Cognitive function was assessed with a battery of 11 neuropsychological tests on the admission day and the seventh day after surgery, respectively.

Results

A total of 96 of 106 patients completed the study, and their data were finally analyzed. POCD occurred in 12 (26.7%) of 45 patients in the probiotic group and 29 (56.9%) of 51 patients in the placebo group (relative risk [RR], 0.47 [95% confidence interval [CI], 0.27 to 0.81]; P = 0.003). Among them, mild POCD occurred in 11 (24.4%) in the probiotic group and 24 (47.1%) in the placebo group (RR, 0.52 [95% CI, 0.29 to 0.94]; P = 0.022). No significant difference in severe POCD incidence was found between the two groups (P = 0.209). Compared with the placebo group, the verbal memory domain cognitive function was mainly improved in the probiotic group.

Conclusion

Probiotics may be used perioperatively to prevent POCD development and improve verbal memory performance in elderly patients receiving hip or knee arthroplasty.

Clinical trial registration

www.chictr.org.cn, identifier: ChiCTR2100045620.

Gut microbiota-mediated metabolic restructuring aggravates emotional deficits after anesthesia/surgery in rats with preoperative stress

Patients with preoperative stress are prone to postoperative emotional deficits. However, the underlying mechanisms are largely unknown. Here, we characterize the changes of microbial composition and specific metabolites after anesthesia/surgery in rats with preoperative stress based on 16S rRNA gene sequencing and non-targeted metabolomics technique. Consequently, we found that anesthesia/surgery aggravated anxiety-like and depression-like behaviors in rats under preoperative stress. Microglia were activated and pro-inflammatory cytokines, including interleukin 6 (IL-6) and tumor necrosis factor ɑ (TNF-α) were upregulated after anesthesia/surgery. The postoperative gut microbiota and metabolite composition of rats exposed to preoperative stress differed from those of control rats. Lastly, emotional impairments, metabolic alterations, and neuroinflammation returned normal in antibiotics-treated rats. Our findings provide further evidence that abnormalities in the gut microbiota contribute to postoperative metabolic restructuring, neuroinflammation, and psychiatric deficits in rats under preoperative stress.

Effects of biophilic virtual reality on cognitive function of patients undergoing laparoscopic surgery: study protocol for a sham randomised controlled trial

INTRODUCTION

Virtual reality (VR) is already being used for cognitive or emotional rehabilitation. However, its role in postoperative cognitive dysfunction (POCD) has not been fully recognised. Due to the lack of an effective postoperative follow-up system, the incidence of POCD in China is not clear, and although many drugs have been proposed to improve POCD in the animal study, their clinical applications are limited, while VR provides an innovative method to provide non-pharmacological management.

METHODS AND DESIGN

This is a single-centre, randomised, double-blind, sham-controlled clinical trial. In this study, 600 patients over 55 years old undergoing laparoscopic surgery will be recruited. Participants will be randomly assigned to receive biophilic VR or sham VR (1:1 ratio), all patients have 20 min of exposure per day during the hospital stay. The primary outcome is the impact of VR on the incidence of POCD. Secondary outcomes include perioperative anxiety and instrumental activities of daily living. Changes in the performance of the neurocognitive batteries are measured by a local resident doctor. Serum samples will be collected on the day before surgery and 7 days after surgery.

ETHICS AND DISSEMINATION

This trial has ethical approval from the Medical Ethics Committee of the Affiliated Hospital of Medical School of Ningbo University (KY20210302). The study is sponsored by Ningbo University and Ningbo Science and Technology Bureau.

CONTACT

Dr. Mao Haijiao, Chair of the hospital medical Ethics committee (ndfylunli@126.com). Trial results will be submitted for publication in peer-reviewed journals, patient recruitment began in April 2021. Written informed consent is obtained for all participants. All information acquired will be disseminated via national or international conferences and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ChiCTR2000040919.

Cognitive impairment and frailty screening in older surgical patients: a rural tertiary care centre experience

Introduction

Despite a clear association between cognitive impairment and physical frailty and poor postoperative outcomes in older adults, preoperative rates are rarely assessed. We sought to implement a preoperative cognitive impairment and frailty screening programme to meet the unique needs of our rural academic centre.

Methods

Through stakeholder interviews, we identified five primary drivers underlying screening implementation: staff education, technology infrastructure, workload impact, screening value and patient–provider communication. Based on these findings, we implemented cognitive dysfunction (AD8, Mini-Cog) and frailty (Clinical Frailty Scale) screening in our preoperative care clinic and select surgical clinics.

Results

In the preoperative care clinic, many of our patients scored positive for clinical frailty (428 of 1231, 35%) and for cognitive impairment (264 of 1781, 14.8%). In our surgical clinics, 27% (35 of 131) and 9% (12 of 131) scored positive for clinical frailty and cognitive impairment, respectively. Compliance to screening improved from 48% to 86% 1 year later.

Conclusion

We qualitatively analysed stakeholder feedback to drive the successful implementation of a preoperative cognitive impairment and frailty screening programme in our rural tertiary care centre. Preliminary data suggest that a clinically significant proportion of older adults screen positive for preoperative cognitive impairment and frailty and would benefit from tailored inpatient care.

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

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

Postoperative cognitive dysfunction in older surgical patients associated with increased healthcare utilization: a prospective study from an upper-middle-income country

BACKGROUND

Perioperative neurocognitive disorder includes postoperative cognitive dysfunction (POCD) and postoperative delirium (POD). Concerning inconclusive consequences of POCD compared with POD, we explored the association between either POCD or POD and functional decline as well as healthcare utilization.

METHODS

Patients aged at least 60 years who underwent a major operation were enrolled. POCD was defined as a decrease in the Montreal Cognitive Assessment (MoCA) score (≥ 2) 1 week after surgery. Postoperative delirium (POD) was defined according to the criteria of the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). The primary outcome was instrumental activities of daily living (IADLs) 3 months after discharge. Secondary outcomes were the length of stay (LOS), hospital cost, and factors that affected functional decline 3 months after surgery. The multivariate model, including potential confounding factors, namely age, gender, surgery type, and postoperative complications, was used to analyze possible factors that influenced a reduction in function, and the results were expressed by using adjusted relative risk (RR) and 95%CI.

RESULTS

Two hundred eighty-nine patients with a mean age of 72 years were enrolled. The incidence of POCD at 1 week was 28.5%. At their 3-month follow-ups, the patients with POCD were not associated with IADL decline. Nevertheless, patients with POCD were more likely to need a prolonged LOS (11 days [1, 46] vs. 8 days [2, 42]; P = 0.01), and incur higher hospital costs (8973.43 USD [3481.69, 11 763.74] vs. 5913.62 USD [332.43, 19 567.33]; P < 0.001). Additionally, the patients experiencing POD demonstrated increased risks of reducing their IADLs (adjusted RR 2.33; 95% CI, 1.15-4.71; P = 0.02).

CONCLUSIONS

POCD at 1 week leaded to increase healthcare utilization in a middle-income country. POD during hospitalization was associated with a decline in function after surgery and increased health care utilization.

TRIAL REGISTRATION

Thai Clinical Trials Registry TCTR20190115001 .

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

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

Varenicline improved laparotomy-induced cognitive impairment by restoring mitophagy in aged mice

Growing incidence of postoperative cognitive dysfunction (POCD) in the elderly populations after major surgery challenges us to provide stable and effective treatments. Mitochondria dysfunction is essential in the pathogenesis of aging and neurodegenerative diseases. It is hypothesized that varenicline improves cognitive impairment through restoring mitophagy and tau phosphorylation. Wild type C57BL/6 mice (male, 18-month-old) were subjected to laparotomy with or without chronic varenicline administration. Postoperative cognition and anxiety were determined by Morris water maze and elevated plus maze tests. Meanwhile, oxidative stress, mitochondria function, mitophagy and tau phosphorylation, as well as the correlation of PKR and STAT3 were characterized. In aged mice following laparotomy, persistent cognitive dysfunction in spatial learning and memory were indicated by longer escape latency and less crossing frequency in the target quadrant. Laparotomy also induced anxiety responses deficits. After postoperative 14 days, significant ROS accumulation and smaller mitochondria with impaired function were presented in the hippocampus. Simultaneously, there were abundant of neuronal apoptosis and translocation of tau phosphorylation in the mitochondria. Enhanced mitophagy and down regulated ChAT activity were distributed in the mice subjected to laparotomy. PKR signaling was activated and required for subcellular activation of STAT3 in the brain. After chronic varenicline administration (1 mg/kg/day), cognitive dysfunction, hippocampal oxidative stress, as well as fragile mitophagy were improved. Our results highlight that laparotomy caused cognitive impairment with persistent oxidative stress, mitochondria dysfunction and autophagy dysregulation. PKR/STAT3 maybe the potential mechanism, and perioperative varenicline treatment could be an efficient therapeutic strategy for POCD.

Does Preoperative Cognitive Optimization Improve Postoperative Outcomes in the Elderly?

Perioperative neurocognitive disorder (PND) is a growing concern, affecting several million elderly patients each year in the United States, but strategies for its effective prevention have not yet been established. Humeidan et al. recently demonstrated that preoperative brain exercise resulted in a decrease in postoperative delirium incidence in elderly surgical patients, suggesting the potential of presurgical cognitive optimization to improve postoperative cognitive outcomes. This brief review summarizes the current knowledge regarding preoperative cognitive optimization and highlights landmark studies, as well as current ongoing studies, as the field is rapidly growing. This review further discusses the benefit of cognitive training in non-surgical elderly populations and the role of cognitive training in patients with preexisting cognitive impairment or dementia. The review also examines preclinical evidence in support of cognitive training, which can facilitate understanding of brain plasticity and the pathophysiology of PND. The literature suggests positive impacts of presurgical cognitive optimization, but further studies are encouraged to establish effective cognitive training programs for elderly presurgical patients.

Processed intraoperative burst suppression and postoperative cognitive dysfunction in a cohort of older noncardiac surgery patients

Postoperative cognitive dysfunction (POCD) is a decline in cognitive test performance which persists months after surgery. There has been great interest in the anesthesia community regarding whether variables generated by commercially available processed EEG monitors originally marketed to prevent awareness under anesthesia can be used to guide intraoperative anesthetic management to prevent POCD. Processed EEG monitors represent an opportunity for anesthesiologists to directly monitor the brain even if they have not been trained to interpret EEG waveforms. There is continued equipoise regarding whether any of the variables generated by the machines' interpretation of raw data are associated with POCD. Most literature has focused on the depth of anesthesia number, however recent studies have shown that processed depth may not be accurate in older age groups due to reduced alpha band power. Burst suppression is an encephalographic pattern of high voltage activity alternating with periods of electrical silence and is another marker of depth which can be obtained from commercial processed EEG monitors. We performed a prospective cohort study to determine whether burst suppression and burst suppression ratio as measured by the BIS Monitor (Bispectral Index, BIS Medtronic, Boulder CO), is associated with cognitive dysfunction 3 months after surgery. We recruited 167 elective surgery patients, 65 years of age and older, anticipated to require at least 2 day inpatient admission. Our main outcome measure was cognitive decline in composite z-score on the Alzheimer's Disease Research Center UDS Battery of at least 1 standard deviation 3 months after surgery relative to preoperative baseline. 14% experienced POCD, this group was older (72 [70, 74] versus 70 [67, 75] years), and had frailty scores as measured by the FRAIL Scale (2 [0, 3] versus 1 [0, 2]) and lower baseline z-scores (- 0.2 [- 0.6, 0.5] versus 0.1 [- 0.3, 0.5]). There was a univariable association between suppression ratio > 10 (SR > 10) and POCD (4.8 [0, 37.3] versus 15.4 [4.0-142.4] min), p = .038. However, after adjustment this relationship did not persist, only anesthetic technique, age, and pain remained in the model. In our cohort of older elective noncardiac surgery patients we found a marginal association between processed burst suppression (total burst suppression p = .067, SR > 5 p = .052, SR > 10.038) which did not persist in a multivariable model. Patients with POCD had almost twice the number of minutes of burst suppression, and three times the amount of time for SR > 5 and > 10. Our finding may be a limitation of the monitor's ability to detect burst suppression. The consistent trend towards more intraoperative burst suppression in patients who developed POCD suggests that future studies are needed to investigate the relationship of raw intraoperative burst suppression and POCD.Trial registry Clinical trial number and registry URL: Optimizing Postoperative Cognitive Dysfunction in the Elderly-PRESERVE, Clinical Trials Gov# NCT02650687; https://clinicaltrials.gov/ct2/show/NCT02650687 .

Depression and anxiety symptoms are related to pain and frailty but not cognition or delirium in older surgical patients

OBJECTIVE

In community dwelling older adults, depression and anxiety symptoms can be associated with early cognitive decline. Symptoms of depression and anxiety are common in older adults prior to surgery. However, their significance is unknown. Our objective was to determine whether preoperative depression and anxiety symptoms are associated with postoperative cognitive decline (POCD) and in-hospital delirium, in older surgical patients.

METHODS

We conducted a secondary data analysis of postoperative cognitive dysfunction in a cohort study of patients 65 and older undergoing elective noncardiac surgery. We used the Hospital Anxiety and Depression Scale (HADS) to screen for depression and anxiety symptoms at a home visit prior to surgery and 3 months after surgery. Patients with a history of psychiatric (major depressive disorder, bipolar disorder, and schizophrenia) or neurologic disorder (Parkinson's disease and stroke) were excluded from the parent study.

RESULTS

Out of the 167 patients, 9.6% (n = 16) reported significant depressive symptoms and 21.6% (n = 36) reported significant anxiety symptoms on preoperative screening. There was no association between preoperative or new-onset postoperative depression and anxiety symptoms and the incidence of delirium or POCD three months after surgery. Patients with preoperative depressive symptoms had higher preoperative pain (scores 69 vs. 35.7, p = .002) and frailty (56 vs. 14.6, p <.001).

CONCLUSION

In our cohort, we did not detect an association between preoperative depression and anxiety symptoms and neurocognitive disorders. Preoperative depression and anxiety symptoms were related to physical pain and frailty. Taken together, these suggest that in patients without a formal psychiatric diagnosis, preoperative depression and anxiety symptoms are related to physical state rather than a harbinger of early cognitive decline. Future studies are needed to understand the nature of the relationship between depression and anxiety symptoms and physical state in surgical patients.

Effects of modified version of the Hospital Elder Life Program on post-discharge cognitive function and activities of daily living among older adults undergoing total knee arthroplasty

OBJECTIVES

This study aimed to investigate the effects of a modified Hospital Elder Life Program (mHELP) on post-discharge cognition and physical function among older adults undergoing total knee arthroplasty (TKA), and to evaluate the incidence of postoperative delirium.

DESIGN

Non-randomized intervention trial.

SETTING AND PARTICIPANTS

A total of 140 patients aged 60 years and older scheduled for elective orthopedic surgery at our institution between August 2017 and December 2018 were included.

METHODS

Ward-level stratification was used with one surgical ward receiving mHELP (intervention group), including orientation communication, early mobilization, vision/hearing impairment equipment, and dehydration prevention, and another ward providing usual care (control group). All participants were assigned to two surgical wards. Outcome measures were collected using MMSE telephone version (tMMSE), activities of daily living (ADL) and instrumental activities of daily living (IADL) instruments at 1, 6, and 12 months after discharge. Multiple linear regression analysis was used to measure effects of mHELP intervention on mean differences in tMMSE, ADL and IADL scores from baseline to 1-, 6- and 12-months.

RESULTS

Effects of mHELP intervention significantly preserved cognitive function at 1 and 12 months, but not at 6 months, compared with controls, regardless of adjustments for confounders. However, no intervention effects were noted in ADL and IADL scores. Postoperative delirium in the whole cohort was 3.6 % (2.5 % in intervention group, 5.1 % in control group, P = 0.41).

CONCLUSIONS

mHELP intervention preserves post-discharge cognitive function, but has no notable effect on ADL and IADL function in older adults undergoing elective TKA surgery.

NLRP3 inflammasomes are involved in the progression of postoperative cognitive dysfunction: from mechanism to treatment

Postoperative cognitive dysfunction (POCD) involves patient memory and learning decline after surgery. POCD not only presents challenges for postoperative nursing and recovery but may also cause permanent brain damage for patients, including children and the aged, with vulnerable central nervous systems. Its occurrence is mainly influenced by surgical trauma, anesthetics, and the health condition of the patient. There is a lack of imaging and experimental diagnosis; therefore, patients can only be diagnosed by clinical observation, which may underestimate the morbidity, resulting in decreased treatment efficacy. Except for symptomatic support therapy, there is a relative lack of effective drugs specific for the treatment of POCD, because the precise mechanism of POCD remains to be determined. One current hypothesis is that postoperative inflammation promotes the progression of POCD. Accumulating research has indicated that overactivation of NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasomes contribute to the POCD progression, suggesting that targeting NLRP3 inflammasomes may be an effective therapy to treat POCD. In this review, we summarize recent studies and systematically describe the pathogenesis, treatment progression, and potential treatment options of targeting NLRP3 inflammasomes in POCD patients.