Elevated postoperative inflammatory biomarkers are associated with short- and medium-term cognitive dysfunction after coronary artery surgery

The link between the early surgery-induced inflammatory response and postoperative cognitive dysfunction in older patients

BACKGROUND

Postoperative cognitive dysfunction (POCD) is a common complication in older patients with cancer and is associated with decreased quality of life and increased disability and mortality rates. Systemic inflammation resulting in neuroinflammation is considered important in the pathogenesis of POCD. The aim of this study was to explore the association between the early surgery-induced inflammatory response and POCD within 3 months after surgery in older cancer patients.

METHODS

Patients ≥65 years in need of surgery for a solid tumor were included in a prospective cohort study. Plasma levels of C-reactive protein (CRP), interleukin-1 beta (IL-1β), IL-6, IL-10, and Neutrophil gelatinase-associated lipocalin (NGAL) were measured perioperatively. Cognitive performance was assessed preoperatively and 3 months after surgery. POCD was defined as a decline in cognitive test scores of ≥25% on ≥2 of five tests within the different cognitive domains of memory, executive functioning, and information processing speed. Logistic regression analysis was performed.

RESULTS

POCD was observed in 44 (17.7%) of 248 included patients. Age >75, preoperative Mini-Mental State Examination (MMSE) score ≤26 and major surgery were independent significant predictors for POCD. In multivariate logistic regression analysis, no significant associations were shown between the early surgery-induced inflammatory response and either POCD or decline within the different cognitive domains.

CONCLUSIONS

This study shows that one out of six older patients with cancer developed POCD within 3 months after surgery. The early surgery-induced inflammatory response was neither associated with POCD, nor with decline in the separate cognitive domains. Further research is necessary for better understanding of the complex etiology of POCD.

Perioperative Ketamine and Cancer Recurrence: A Comprehensive Review

Cancer is a significant global health threat and a leading cause of death worldwide. Effective early-stage interventions, particularly surgery, can potentially cure many solid tumors. However, the risk of postoperative cancer recurrence remains high. Recent research highlights the influence of perioperative anesthetic and analgesic choices on the fate of residual cancer cells, potentially affecting recurrence risks. Among these agents, ketamine-a well-known anesthetic and analgesic-has garnered interest due to its antitumor properties, mainly through inhibiting the N-methyl-D-aspartate (NMDA) receptor found in various cancer tissues. Additionally, ketamine's potential immunomodulatory effects, given the expression of NMDA receptors on immune cells, suggest that it plays a significant role during the perioperative period. This review synthesizes current evidence on ketamine's impact on cancer cell biology, inflammation, immune modulation, and the role of the gut microbiota, proposing ketamine as a promising agent for enhancing oncological outcomes.

Effects of short-term preoperative intranasal dexmedetomidine plus conventional treatment on delirium following cardiac surgery in patients with sleep disorders

STUDY OBJECTIVES

To assess whether preoperative dexmedetomidine (DEX) nasal drips combined with conventional treatment could mitigate the occurrence of postoperative delirium (POD).

DESIGN

A prospective randomised controlled study.

SETTING

The cardiac surgery intensive care unit (CSICU) and patient hospitalisation ward at a university hospital.

PARTICIPANTS

A total of 100 patients (aged ≥60 years) undergoing cardiac surgery at a university hospital between 7 January 2022, and 30 November 2022 met the eligibility criteria and were included in the study.

INTERVENTIONS

Patients with sleep disorders (Pittsburgh Sleep Quality Index ≥8) were divided into two groups: Group A (the placebo group, n=50), receiving a short-term preoperative placebo combined with conventional treatment and Group B (the DEX group, n=50), receiving short-term preoperative DEX combined with conventional treatment.

MEASUREMENTS AND RESULTS

The Confusion Assessment Method for the ICU (CAM-ICU) was used for POD assessment in the CSICU, while the CAM was employed to assess delirium in the patient ward. Group B demonstrated a reduced incidence of POD compared to Group A (12% vs. 30%, odds ratio: 0.318, 95% confidence interval: 0.112-0.905, p=0.027).

CONCLUSION

The combined treatment involving DEX demonstrated a decreased incidence of POD in elderly individuals with sleep disorders undergoing cardiac surgery compared to the placebo combination treatment.

TRIAL REGISTRATION

URL: www.chictr.org.cn with registration number ChiCTR 2100043968, registered on 06/03/2021.

Single exposure to anesthesia/surgery in neonatal mice induces cognitive impairment in young adult mice

BACKGROUND

The effects of a solitary neonatal exposure to anesthesia plus surgery (anesthesia/surgery) on cognitive function and the underlying mechanism in developing brains remains largely undetermined. We, therefore, set out to investigate the impact of single exposure to anesthesia/surgery in neonatal mice.

METHODS

Six-day-old male and female mice received abdominal surgery under 3% sevoflurane plus 50% oxygen for 2 h. The new object recognition (NOR) and Morris water maze (MWM) were used to evaluate cognitive function in young adult mice. Western blot, ELISA and RT-PCR were used to measure levels of NR2B and IL-6 in medial prefrontal cortex and IL-6 in blood of the mice. We employed NR2B siRNA and IL-6 antibody in the interaction studies.

RESULTS

The anesthesia/surgery decreased the ratio of novel time to novel plus familiar time in NOR and the number of platform crossings, but not escape latency, in MWM compared to sham condition. The mice in anesthesia/surgery group had increased NR2B expression in medial prefrontal cortex, and IL-6 amounts in blood and medial prefrontal cortex. Local injection of NR2B siRNA in medial prefrontal cortex alleviated the anesthesia/surgery-induced cognitive impairment. IL-6 antibody mitigated the anesthesia/surgery-induced upregulation of NR2B and cognitive impairment in young adult mice.

CONCLUSIONS

These results suggest that a single neonatal exposure to anesthesia/surgery causes impairment of memory, but not learning, in young adult mice through IL-6-regulated increases in NR2B concentrations in medial prefrontal cortex, highlighting the need for further research on the underlying mechanisms of anesthesia/surgery's impact on cognitive function in developing brains.

Systemic inflammation, neuroinflammation and perioperative neurocognitive disorders

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

Impact of ketamine versus propofol for anesthetic induction on cognitive dysfunction, delirium, and acute kidney injury following cardiac surgery in elderly, high-risk patients

Objective

Evaluate the effects of ketamine versus propofol when used for induction of anesthesia in elderly, high-risk cardiac surgical patients on postoperative complications including cognitive dysfunction, delirium, and acute kidney injury.

Methods

Prospective, randomized study performed at a tertiary medical center. A total of 52 patients aged ≥70 and older presenting for complex cardiac surgery were randomized to receive either ketamine or propofol for induction of anesthesia. Patients underwent a battery of cognitive testing preoperatively and postoperatively and the incidence of delirium and acute kidney injury were measured. Norepinephrine (NEE) equivalents following induction were assessed for each group.

Results

A total of 49 patients were included, 25 in the ketamine group and 24 in the propofol group with 3 patients excluded from the analysis. No difference was found between groups in either postoperative cognitive dysfunction or delirium incidence. Acute kidney injury occurred in 6 (24%) patients in the ketamine group in 12 (50%) patients in the propofol group, but the difference did not meet statistical significance (P = 0.08; Relative Risk = 2.1, 95% CI 0.9-4.7). NEE equivalents were lower in the ketamine group, 9.6 ± 22.2 versus 32.7 ± 46.0, P < 0.03.

Conclusions

The use of ketamine versus propofol for induction of anesthesia did not impact the incidence of postoperative cognitive dysfunction or delirium. Twice as many patients in the propofol group developed acute kidney injury, although not reaching statistical significance and warranting further investigation. In elderly, high-risk patients, ketamine was associated with a significantly reduced need for vasopressor support following induction.

Effect of Quadratus Lumborum Block on Pain and Stress Response after Video Laparoscopic Surgeries: A Randomized Clinical Trial

Background: There are many surgical and anesthetic factors that affect pain and the endocrine–metabolic response to trauma. The ability of anesthetic agents and neuronal blockade to modify the response to surgical trauma has been widely studied in the last few years. Objective: To evaluate if the anterior quadratus lumborum block contributes to improved surgical recovery, using as parameters analgesia, pulmonary function and neuroendocrine response to trauma. Methods: We carried out a prospective, randomized, controlled, and blinded study, in which 51 patients scheduled for laparoscopic cholecystectomy. Patients were randomly selected and assigned to 2 groups. The control group received balanced general anesthesia and venous analgesia, and the intervention group was treated under general, venous analgesia and anterior quadratus lumborum block. The parameters evaluated were: demographic data, postoperative pain, respiratory muscle pressure and inflammatory response to surgical stress with the plasma dosage of IL-6 (Interleukin 6), CRP (C-Reactive protein) and cortisol. Results: Anterior quadratus lumborum block induced the slowing of IL-6 cytokine production and a decrease in cortisol release. This effect was accompanied by the significant reduction of postoperative pain scores. Conclusion: Anterior quadratus lumborum block is an important strategy for analgesia in abdominal laparoscopic surgery and contributes to reducing the inflammatory response to surgical trauma with an early return of preoperative baseline physiological functions.

Long-Term Seizure Outcomes and Predictors in Patients with Dysembryoplastic Neuroepithelial Tumors Associated with Epilepsy

OBJECTIVE

To determine the predictors and the long-term outcomes of patients with seizures following surgery for dysembryoplastic neuroepithelial tumors (DNTs); Methods: Clinical data were collected from medical records of consecutive patients of the Department of Neurosurgery of Sanbo Brain Hospital of Capital Medical University with a pathological diagnosis of DNT and who underwent surgery from January 2008 to July 2021. All patients were followed up after surgery for at least one year. We estimated the cumulative rate of seizure recurrence-free and generated survival curves. A log-rank (Mantel-Cox) test and a Cox proportional hazard model were performed for univariate and multivariate analysis to analyze influential predictors; Results: 63 patients (33 males and 30 females) were included in this study. At the final follow-up, 49 patients (77.8%) were seizure-free. The cumulative rate of seizure recurrence-free was 82.5% (95% confidence interval (CI) 71.8-91.3%), 79.0% (95% CI 67.8-88.6%) and 76.5% (95% CI 64.8-87.0%) at 2, 5, and 10 years, respectively. The mean time for seizure recurrence-free was 6.892 ± 0.501 years (95% CI 5.91-7.87). Gross total removal of the tumor and a short epilepsy duration were significant predictors of seizure freedom. Younger age of seizure onset, bilateral interictal epileptiform discharges, and MRI type 3 tumors were risk factors for poor prognosis; Conclusions: A favorable long-term seizure outcome was observed for patients with DNT after surgical resection. Predictor analysis could effectively guide the clinical work and evaluate the prognosis of patients with DNT associated with epilepsy.

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.

Study on the Effect of Dexmedetomidine on Postoperative Cognitive Dysfunction and Inflammation in Aged Rats

Objective

The aim of this study is to investigate the effect of dexmedetomidine on cognitive dysfunction and inflammatory cytokines in the hippocampus after surgery in aged rats.

Methods

A total of 30 healthy male Sprague Dawley rats were divided into control group, sham group, and dexmedetomidine group. A splenectomy rat model was established and dexmedetomidine was intraperitoneally injected before operation. The cognitive function of rats was examined by Morris Water-Maze Test, open field experiment, and passive avoidance memory test. And the expression levels of IL-6, IL-1β, and TNF-α in the hippocampus were examined by ELISA.

Results

The escape latency for 5 continuous days in dexmedetomidine group was significantly decreased comparing with control group (all P < 0.05). The number of times of swimming and the percentage of swimming time in dexmedetomidine group were significantly more than those in control group (all P < 0.05). What is more, rats in dexmedetomidine group had the decreased time of stay in the central square and the increased number of standing times in comparison with the control group, and the statistical differences were found (all P < 0.05). Compared with the control group, dexmedetomidine intraperitoneally injected before surgery could significantly inhibit the expression levels of IL-6, IL-1β, and TNF-α in the hippocampus, and there were statistical differences (all P < 0.05).

Conclusion

Dexmedetomidine could significantly relieve the postoperative cognitive dysfunction in aged rats. The mechanism may be associated with the decreased inflammatory cytokines in the hippocampus.

The Impact of General Anesthesia on Redox Stability and Epigenetic Inflammation Pathways: Crosstalk on Perioperative Antioxidant Therapy

Worldwide, the prevalence of surgery under general anesthesia has significantly increased, both because of modern anesthetic and pain-control techniques and because of better diagnosis and the increased complexity of surgical techniques. Apart from developing new concepts in the surgical field, researchers and clinicians are now working on minimizing the impact of surgical trauma and offering minimal invasive procedures due to the recent discoveries in the field of cellular and molecular mechanisms that have revealed a systemic inflammatory and pro-oxidative impact not only in the perioperative period but also in the long term, contributing to more difficult recovery, increased morbidity and mortality, and a negative financial impact. Detailed molecular and cellular analysis has shown an overproduction of inflammatory and pro-oxidative species, responsible for augmenting the systemic inflammatory status and making postoperative recovery more difficult. Moreover, there are a series of changes in certain epigenetic structures, the most important being the microRNAs. This review describes the most important molecular and cellular mechanisms that impact the surgical patient undergoing general anesthesia, and it presents a series of antioxidant therapies that can reduce systemic inflammation.

Is postoperative cognitive decline after cardiac surgery associated with plasma beta amyloid 1-42 levels?

Background

Postoperative cognitive decline following cardiac surgery is one of the frequently reported complications affecting postoperative outcome, characterized by impairment of memory or concentration. The aetiology is considered multifactorial and the research conducted so far has presented contradictory results. The proposed mechanisms to explain the cognitive decline associated with cardiac surgery include the neurotoxic accumulation of β-amyloid (Aβ) proteins similar to Alzheimer's disease. The comparison of coronary artery bypass grafting procedures concerning postoperative cognitive decline and plasmatic Aβ1-42 concentrations has not yet been conducted.

Methods

The research was designed as a controlled clinical study of patients with coronary artery disease undergoing surgical myocardial revascularization with or without the use of a cardiopulmonary bypass machine. All patients completed a battery of neuropsychological tests and plasmatic Aβ1-42 concentrations were collected.

Results

The neuropsychological test results postoperatively were significantly worse in the cardiopulmonary bypass group and the patients had larger shifts in the Aβ1-42 preoperative and postoperative values than the group in which off-pump coronary artery bypass was performed.

Conclusions

The conducted research confirmed the earlier suspected association of plasmatic Aβ1-42 concentration to postoperative cognitive decline and the results further showed that there were less changes and lower concentrations in the off-pump coronary artery bypass group, which correlated to less neurocognitive decline. There is a lot of clinical contribution acquired by this research, not only in everyday decision making and using amyloid proteins as biomarkers, but also in the development and application of non-pharmacological and pharmacological neuroprotective strategies.

An Association Between C-Reactive Protein Levels and the Occurrence of Cognitive Dysfunction After Heart Valve Replacement

Background

Postoperative cognitive dysfunction (POCD) is defined as cognitive dysfunction related to inflammation after surgical procedures, which is common following cardiac surgery. Cognitive deficits are thought to result from a systemic inflammatory response. C-reactive protein (CRP) and other proinflammatory cytokines, which are released in response to inflammation, disrupt the blood–brain barrier and neurotransmission, resulting in POCD. This study aimed to determine the correlation between POCD and increased levels of CRP in patients who had undergone heart valve replacement.

Methods

This study comprised 32 patients with normal cognitive function undergoing heart valve replacement. The CRP levels were measured before surgery and on the second postoperative day, and cognitive function was examined via the Indonesian-adapted Montreal Cognitive Assessment (MOCA-INA) on the third postoperative day. Data were analyzed using Spearman correlation test.

Results

Of the 32 patients, 28 (87.5%) experienced POCD. The median level of CRP was 6.6 mg/dL (interquartile range: 4.0, 8.3 g/dL). According to Spearman correlation test, increased levels of CRP were significantly related to POCD following heart valve replacement (p = 0.003, r = 0.501). The receiver operating characteristic curve indicated that the CRP cutoff level was 3.345 mg/dL, and the sensitivity and specificity were 89.3% and 75%, respectively.

Conclusion

High expression level of CRP was correlated with POCD following heart valve replacement.

Postoperative Effects of Dexmedetomidine on Serum Inflammatory Factors and Cognitive Malfunctioning in Patients with General Anesthesia

Objective

To investigate the effects of dexmedetomidine intervention on serum inflammatory factor concentration and postoperative cognitive malfunction in elderly patients with general anesthesia. Methodology. 174 patients with general anesthesia were selected, who were categorized into a control group (HC) and a dexmedetomidine group (HS) using the random number table method, with 87 patients in individual groups. The dexmedetomidine group was pumped intravenously with dexmedetomidine at a loading dose of 1 μg/kg before induction of anesthesia for 15 min, followed by continuous intravenous pumping at a rate of 0.4 μg/kg/h, and the dosing was stopped at 30 min before concluding the surgery. The control group was administered the identical dose of saline in the same manner. Interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) levels and MMES scores were tested at 1 h before and 24 h after anesthesia.

Results

Comparing to HC group, patients in the HS group had lower TNF-α and IL-6 levels at both scheduled points (P < 0.05).

Conclusion

Dexmedetomidine reduced the expression of inflammatory factors in elderly patients with general anesthesia and effectively reduced the incidence of postoperative cognitive dysfunction after general anesthesia surgery.

Coronary artery revascularizations and cognitive decline - A systematic review

Coronary artery disease (CAD) is a risk factor for cognitive decline. The aim of this study was to systematically review recent literature on whether coronary artery revascularizations are associated to cognitive decline and dementia. Pubmed, Scopus, and CINAHL (EBSCO) were searched systematically from January 2009 till September 2020. Studies were conducted on persons with CAD undergoing coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI) procedure compared to other coronary artery disease treatments, and the outcome was cognitive decline or dementia. Altogether four of the 680 reviewed articles met inclusion criteria. Results were inconsistent, and the outcome measurements heterogeneous between studies. Our findings indicate an evidence gap in the current understanding of long-term outcomes following coronary artery revascularization. However, evidence of long-term effects on cognition would complement our understanding of their benefits. There is a need for more studies on long-term cognitive outcomes after coronary artery revascularizations.

Genetic variations of toll-like receptors: Impact on susceptibility, severity and prognosis of bacterial meningitis

Bacterial meningitis (BM) is a serious infectious disease of the central nervous system，which is mainly caused by Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae, Group B Streptococcus and Listeria monocytogenes. Throughout the world, BM has become one of the most lethal diseases that commonly occurs in children. Toll like receptors (TLRs) are one of the most important immune defense lines in infectious diseases, and play an essential role in host defense. Accumulating evidence shows that genetic variations in TLRs are associated with host responses in BM. This review aims to summarize the role of different TLRs and their genetic variations in the susceptibility, severity and prognosis of BM and discuss the identified risk factors for better treatment and improvement of the course and outcome of BM.

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

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

Effect of quadratus lumborum block on postoperative cognitive function in elderly patients undergoing laparoscopic radical gastrectomy: a randomized controlled trial

Background

Quadratus lumborum block (QLB) is a novel and effective postoperative analgesia method for abdominal surgeries. However, whether QLB can affect early postoperative cognitive function by inhibiting surgical traumatic stress and the inflammatory response remains unclear. This study aimed to explore the effect of QLB on postoperative cognitive function in elderly patients undergoing laparoscopic radical gastrectomy.

Methods

Sixty-four elderly patients who underwent laparoscopic radical gastrectomy were randomly divided into the QLB group (Q group, n = 32) and control group (C group, n = 32). The Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) were used to measure cognitive function 1 day before and 7 days after surgery. Postoperative cognitive dysfunction (POCD) was defined as a decline of ≥ 1 SD in both tests. The visual analog scale (VAS) scores 6 h (T1), 24 h (T2), and 48 h (T3) after surgery were measured. The serum levels of high mobility group box protein 1 (HMGB1), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) were evaluated 1 day before surgery (baseline), and 1 day (day 1) and 3 days after surgery (day 3). The intraoperative remifentanil dosage, sufentanil consumption 24 h after surgery, recovery time from anesthesia, and adverse effects were also compared.

Results

POCD was present in two patients in the QLB group and eight patients in the C group 7 days after surgery (6.7 % vs. 27.6 %, P = 0.032). The MMSE and MoCA scores were similar in both groups preoperatively, and the two scores were higher in the QLB group than in the C group 7 days after surgery (P < 0.05). The VAS scores were significantly lower in the Q group at all times after surgery (P < 0.05). Compared with the C group, the levels of HMGB1, TNF-α, and IL-6 were significantly decreased 1 and 3 days after surgery in the QLB group (P < 0.05). The remifentanil consumption intraoperatively and sufentanil 24 h postoperatively were significantly lower in the QLB group (P < 0.05). The recovery time from anesthesia was shorter in the QLB group (P < 0.05). No severe adverse effects occurred in either group.

Conclusions

QLB could improve postoperative cognitive function in elderly patients undergoing laparoscopic radical gastrectomy. This may be related to the suppression of the inflammatory response after surgery.

Trial registration

Chictr.org.cn identifier ChiCTR1900027574 (Date of registry: 19/11/2019, prospectively registered).

Assessment of risk factors for postoperative cognitive dysfunction after coronary artery bypass surgery: a single-center retrospective cohort study

Aim: To find out risk factors for postoperative cognitive dysfunction (POCD) after coronary artery bypass grafting (CABG), and to provide basis for clinical prevention of POCD. A total of 88 patients who underwent CABG were surveyed with Telephone Questionnaire (TICS-M) for their cognitive impairment after 3, 7, 21, 90, 180 days post-surgery. The occurrence of POCD was diagnosed by Neuropsychological Battery which included Vocabular Learning Test (VLT), Wisconsin Card Sorting Test (WCST), Trail Making Test (TMT) and Symbol Digit Modalities Test (SDMT). The preoperative, intraoperative and postoperative risk factors were assessed by the χ² or t test. Multivariate analysis was used to study the correlation between the risk factors and the occurrence of POCD. Age, aortic plaque, carotid artery stenosis, cerebrovascular disease, anesthesia time, the rate of decline in intraoperative hemoglobin concentration (ΔHb) and systemic inflammatory response syndrome (SIRS) score on postoperative day 2 had statistically significant (P<0.05) influence on the occurrence of POCD. Aortic plaque, carotid artery stenosis, anesthesia time and SIRS score (odds ratio (OR) value > 1, P<0.05) are the risk factors for POCD. The incidence of day-21 and -180 POCD was approximately 26.1 and 22.7%, respectively.

Effects of edaravone on postoperative cognitive function in elderly patients undergoing hip joint replacement surgery: A randomized controlled trial

BACKGROUND

Postoperative cognitive dysfunction (POCD) is a complication of central nervous system in patients after surgery. Edaravone as a brain-protective agent may have protective effect on postoperative cognitive function. The study was designed to explore the effects of edaravone on postoperative cognitive function in elderly patients undergoing hip joint replacement surgery and potential mechanism.

PATIENTS AND METHODS

Patients undergoing hip joint replacement surgery were randomly allocated into 2 groups: the edaravone group (group E) and the control group (group C). Group E received intravenous edaravone at a dose of 0.5 mg/kg after induction of anesthesia, while group C received normal saline. The cognitive function was evaluated with the Mini-Mental State Examination (MMSE) 1day before surgery,3 days and the 7 days after surgery. Patients' plasma samples were collected to detect the levels of S100β protein (S100β), interleukin-6 (IL-6), matrix metalloproteinase-9 (MMP-9), superoxide dismutase (SOD) and malondialdehyde (MDA) before the induction of anesthesia, at the end of surgery and on postoperative day 3.

RESULTS

The MMSE scores in group E were higher than those of group C 3 days after surgery (25.98 ± 1.99 vs 24.86 ± 1.86, p = 0.003). There were remarkable rises (p < 0.05) in plasma IL-6, S100βand MMP-9 levels at the end of surgery and on postoperative day 3 in the two groups, however, edaravone pretreatment could reduce these levels to a certain extent compared with group C (p < 0.05).In group E, the SOD concentration was higher at the end of surgery (16.03 ± 2.46U/ml vs. 13.65 ± 2.53U/ml, p = 0.0001), while the MDA level was lower on postoperative day 3 than those in group C (7.01 ± 2.37 nmol/ml vs. 11.34 ± 3.18 nmol/ml, p = 0.0001).

CONCLUSION

The results indicated that preoperative intervention with edaravone may improve the postoperative cognitive function in elderly patients undergoing hip joint replacement surgery.

Predisposing and Precipitating Factors Associated With Postoperative Delirium in Patients Undergoing Cardiac Surgery at a Veterans Affairs Medical Center: A Pilot Retrospective Analysis

OBJECTIVE

Patients treated at Veterans Affairs (VA) medical centers are in poorer health, experience more medical and psychiatric conditions, and make greater use of medical resources than do patients in the general population. In the present pilot study, the authors examined their recent experience at a VA medical center to determine the incidence and risk factors associated with the development of postoperative delirium in VA patients after cardiac surgery and hypothesized that the risk factors for postoperative delirium after cardiac surgery are different between VA and non-VA patients.

DESIGN

Retrospective cohort study.

SETTING

Clement J. Zablocki Veterans Affairs Medical Center.

PARTICIPANTS

The study comprised 250 consecutive patients undergoing cardiac surgery from July 2014 to March 2016.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Demographics, coexisting diseases, and medications were obtained from the VA electronic medical record. The European System for Cardiac Operative Evaluation II mortality risk index was calculated for each patient. The type and duration of the procedure and the duration of bypass were recorded. Intraoperative crystalloid, colloid, cell saver, and blood product volumes were compiled. Progress notes and International Classification of Diseases, Tenth Revision, Clinical Modification codes were searched for documentation of postoperative delirium. Thirty-eight patients (15.2%) developed postoperative delirium. Stepwise logistic regression analysis demonstrated that the European System for Cardiac Operative Evaluation II mortality risk index (odds ratio [OR] 1.036, 95% confidence interval [CI] [1.003-1.070]; p = 0.0344), congestive heart failure (OR 2.223 [95% CI 1.046-4.722]; p = 0.0377), pre-existing cognitive impairment (OR 5.147 [95% CI 1.994-13.28]; p = 0.0007), and the presence of a neuropsychiatric disorder (OR 2.015 [95% CI 1.004-4.043]; p = 0.0487) were predisposing factors associated with higher odds of postoperative delirium. The duration of surgery; transfusion of blood products (including packed red blood cells, fresh frozen plasma, and platelets); the durations of mechanical ventilation and conscious sedation (using either propofol or dexmedetomidine); and the length of intensive care unit stay were precipitating factors associated with higher odds of postoperative delirium.

CONCLUSIONS

The results demonstrate that congestive heart failure, pre-existing cognitive impairment, and the presence of a neuropsychiatric disorder are predisposing risk factors for postoperative delirium after cardiac surgery in VA patients, whereas the duration of surgery, transfusion of blood products, durations of mechanical ventilation and conscious sedation, and length of intensive care unit stay are precipitating factors for postoperative delirium. These findings in VA patients generally are similar to those observed in the civilian population despite the differences between these cohorts.

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

BACKGROUND

Inflammation plays a key role in the etiology and pathology of postoperative cognitive dysfunction (POCD). Cyclooxygenase (COX)-2 inhibitor parecoxib is used for the treatment of acute pain due to its potent anti-inflammatory and analgesic effects. Herein, we evaluated the efficacy and safety of parecoxib on early POCD in geriatric patients.

OBJECTIVE

This study was performed to evaluate the efficacy and safety of parecoxib for early postoperative cognitive dysfunction (POCD) in elderly patients.

METHODS

Comprehensive literature search based on six electronic databases was applied to retrieve all related randomized controlled trials (RCTs). Two independent reviewers screened each article for eligibility according to the predetermined inclusion criteria. The Cochrane's Tool was applied to evaluate the methodological quality of included studies. RevMan 5.3 was used to conduct meta-analysis.

RESULTS

Eight RCTs comprising a total of 1106 subjects prepared for orthopedic surgical operation were selected. All the identified RCTs were conducted in China. The methodological qualities of included studies were judged to be medium to high. The integrated data showed that perioperative intravenous parecoxib could remarkably reduce the incidence of POCD with improved Mini-Mental State Examination (MMSE) score. Parecoxib could significantly reduce the concentrations of interleukin-6, but results regarding the changes in tumor necrosis factor-alpha, C-reactive protein, and S100β levels remained inconsistent.

CONCLUSION

Perioperative parecoxib administration is effective in reducing the incidence of POCD and improving the MMSE score compared with control. However, the beneficial effect of parecoxib has been tested only in the Chinese population. Future RCTs in western countries with larger-scale and more comprehensive neurological tests are needed.

Neurological dysfunction after cardiac surgery and cardiac intensive care admission: A narrative review part 2: Cognitive dysfunction after critical illness; potential contributors in surgery and intensive care; pathogenesis; and therapies to prevent/treat perioperative neurological dysfunction

Severe cognitive decline and cognitive dysfunction has been attributed to patient's stay in the cardiovascular intensive care unit. Prolonged mechanical ventilation, long duration of stay, sedation protocols, and sleep deprivation contribute to patients developing neurocognitive disorder after intensive care admission and it is associated with poor clinical outcomes. Trauma of surgery, stress of critical care, and administration of anaesthesia evoke a systemic inflammatory response and trigger neuroinflammation and oxidative stress. Anaesthetic agents modulate the function of the GABA receptors. The persistence of these effects in the postoperative period promotes development of cognitive dysfunction. A number of drugs are under investigation to restrict or prevent this cognitive decline.

Relationship among anesthesia technique, surgical stress, and cognitive dysfunction following spinal surgery: a randomized trial

OBJECTIVE

Surgical trauma is known to result in systemic inflammatory changes that can lead to postoperative cognitive dysfunction. In the present study, the authors compared the effects of an epidural anesthesia protocol to those of traditional anesthesia with regard to postoperative inflammatory changes, cellular immunity, and cognitive dysfunction.

METHODS

Forty-eight patients, ages 45-60 years, underwent multilevel thoracolumbar decompression and fusion and were randomly assigned to one of two groups: group 1 (27 patients) had combined epidural and general anesthesia, followed by epidural analgesia for 48 hours after surgery, and group 2 (21 patients) had general anesthesia, followed by traditional opioid pain management after surgery. At multiple time points, data on pain control, cognitive function, cellular immunity, and inflammatory markers were collected.

RESULTS

Group 1 patients demonstrated lower pain levels, less systemic inflammation, less cellular immune dysfunction, and less postoperative cognitive dysfunction than group 2 patients.

CONCLUSIONS

The use of combined epidural and general anesthesia followed by postoperative epidural analgesia during the first 48 hours after multilevel thoracolumbar decompression and fusion surgery had a significant positive effect on pain management, cellular immune function, systemic inflammation, and postoperative cognitive function.Clinical trial registration no.: 115080510080 (http://rosrid.ru).

C-reactive protein for risk prediction of post-operative delirium and post-operative neurocognitive disorder

BACKGROUND

Post-operative delirium (POD) and post-operative neurocognitive disorder (NCD) are frequently seen in the elderly. Development of biomarkers for pre-operative risk prediction is of major relevance. As inflammation present before surgery might predispose to POD and post-operative NCD development, we aim to determine associations between pre-operative C-reactive protein (CRP) and the incidence of POD and post-operative NCD.

METHODS

In this observational study, we analyzed 314 patients enrolled in the SuDoCo trial, who had a pre-operative CRP measurement the day before surgery. Primary outcomes were POD assessed according DSM-4 from day 1 until day 7 after surgery and post-operative NCD assessed 3 months after surgery. We conducted multivariable logistic regression analysis adjusted for age, sex, randomization, body mass index, MMSE, ASA status, infection/autoimmune disease/malignoma and types of surgery to determine associations between CRP with POD and post-operative NCD, respectively.

RESULTS

Pre-operative CRP was independently associated with POD [OR 1.158 (95% CI 1.040, 1.291); P = .008]. Patients with CRP values ≥5 mg/dL had a 4.8-fold increased POD risk [OR 4.771 (95% CI 1.765, 12.899; P = .002)] compared to patients with lower CRP values. However, no association was seen between pre-operative CRP and post-operative NCD [OR 0.552 (95% CI 0.193, 1.581); P = .269].

CONCLUSIONS

Pre-operative CRP levels were independently associated with POD but not post-operative NCD after three months. Moreover, higher pre-operative CRP levels showed higher risk for POD. This strengthens the role of inflammation in the development of POD. Assessment of CRP before surgery might allow risk stratification of POD.

TRIAL REGISTRATION

This study was registered with ISRCTN Register 36437985 on 02 March 2009.

Effects of deep neuromuscular blockade on the stress response during laparoscopic gastrectomy Randomized controlled trials

Maintaining deep neuromuscular block during surgery improves surgical space conditions. However, its effects on patient outcomes have not been well documented. We examined whether maintaining deep neuromuscular blockade during surgery could decrease the stress response compared to moderate neuromuscular blockade. Patients undergoing laparoscopic gastrectomy were randomly allocated to either the moderate (train-of-four counts of 1–2) or deep (post-tetanic counts of 1–2) neuromuscular blockade group. The primary outcome variable was the postoperative blood level of interleukin-6, and the secondary outcome variables were intraoperative or postoperative blood levels of tumor necrosis factor-α, interleukin-1β, interleukin-8, and C-reactive protein. A total of 96 patients were recruited and 88 (44 in each group) were included in the analyses. The levels of tumor necrosis factor-α and interleukin-1β measured at the end of surgery, interleukin-6 and interleukin-8 measured at 2 h postoperatively, and C-reactive protein measured at 48 h postoperatively were all significantly increased compared to the preoperative values, but there were no differences between the moderate and deep neuromuscular block groups. We found no differences in surgical stress response measured using determining levels of interleukin-6 and other mediators released between the moderate and deep neuromuscular blockade groups in patients undergoing laparoscopic gastrectomy.

Cognitive Effects of Perioperative Pregabalin

EDITOR’S PERSPECTIVE

What We Already Know about This Topic

Perioperative administration of pregabalin has been associated with decreased postoperative pain and opioid requirements

What This Article Tells Us That Is New

This secondary analysis of data demonstrating that perioperative administration of pregabalin was associated with a reduction in opioid requirements and incisional hyperalgesia suggests that these benefits may be compromised by an increased risk of developing impaired postoperative cognitive performance

Background

Pregabalin has shown opioid sparing and analgesic effects in the early postoperative period; however, perioperative effects on cognition have not been studied. A randomized, parallel group, placebo-controlled investigation in 80 donor nephrectomy patients was previously performed that evaluated the analgesic, opioid-sparing, and antihyperalgesic effects of pregabalin. This article describes a secondary exploratory analysis that tested the hypothesis that pregabalin would impair cognitive function compared to placebo.

Methods

Eighty patients scheduled for donor nephrectomy participated in this randomized, placebo-controlled study. Pregabalin (150 mg twice daily, n = 40) or placebo (n = 40) was administered on the day of surgery and the first postoperative day, in addition to a pain regimen consisting of opioids, steroids, local anesthetics, and acetaminophen. Specific cognitive tests measuring inhibition, sustained attention, psychomotor speed, visual memory, and strategy were performed at baseline, 24 h, and 3 to 5 days after surgery, using tests from the Cambridge Neuropsychological Test Automated Battery.

Results

In the spatial working memory within errors test, the number of errors increased with pregabalin compared to placebo 24 h after surgery; median (25th, 75th percentile) values were 1 (0, 6) versus 0 (0, 1; rate ratio [95% CI], 3.20 [1.55 to 6.62]; P = 0.002). Furthermore, pregabalin significantly increased the number of errors in the stop-signal task stop-go test compared with placebo; median (25th, 75th percentile) values were 3 (1, 6) versus 1 (0, 2; rate ratio, 2.14 [1.13 to 4.07]; P = 0.020). There were no significant differences between groups in the paired associated learning, reaction time, rapid visual processing, or spatial working memory strategy tests.

Conclusions

Perioperative pregabalin significantly negatively affected subdomains of executive functioning, including inhibition, and working memory compared to placebo, whereas psychomotor speed was not changed.

Mycobacterium vaccae immunization protects aged rats from surgery-elicited neuroinflammation and cognitive dysfunction

Aging is a major risk factor for developing postoperative cognitive dysfunction. Neuroinflammatory processes, which can play a causal role in the etiology of postoperative cognitive dysfunction, are potentiated or primed as a function of aging. Here we explored whether exposure to a microorganism with immunoregulatory and anti-inflammatory properties, Mycobacterium vaccae NCTC 11659 (M. vaccae), could ameliorate age-associated neuroinflammatory priming. Aged (24 months) and adult (3 months) male F344XBN rats were immunized with heat-killed M. vaccae (3 injections, once per week) before undergoing a laparotomy or anesthesia control procedure. Aged, but not young rats, showed postoperative learning/memory deficits in a fear-conditioning paradigm. Importantly, M. vaccae immunization protected aged rats from these surgery-induced cognitive impairments. M. vaccae immunization also shifted the aged proinflammatory hippocampal microenvironment toward an anti-inflammatory phenotype. Furthermore, M. vaccae immunization reduced age-related hyperinflammatory responses in isolated hippocampal microglia. Overall, our novel data suggest that M. vaccae can induce an anti-inflammatory milieu in the aged brain and thus mitigate the neuroinflammatory and cognitive impairments induced by surgery.

Correlation of cytokines, BDNF levels, and memory function in patients with opioid use disorder undergoing methadone maintenance treatment

BACKGROUND

Patients with opioid use disorder (OUD) show memory deficiencies and impaired treatment outcomes. Emerging evidence suggests that opioid abuse activates proinflammatory processes by increasing cytokine production and impairing neuroprotection, which damages the memory function in OUD patients. Therefore, we investigated whether plasma-based inflammatory and neurotrophic markers correlate with memory function in OUD patients.

METHOD

OUD patients undergoing methadone maintenance therapy (MMT) were investigated and followed up for 12 weeks. Plasma tumor necrosis factor (TNF)-α, C-reactive protein (CRP), interleukin (IL)-6, transforming growth factor (TGF)-β1, brain-derived neurotrophic factor (BDNF) levels, and Wechsler Memory Scale-Revised (WMS-R) scores were assessed at baseline and after 12 weeks of MMT. Multiple linear regressions and generalized estimating equations (GEEs) were used to examine the correlation between cytokines and memory performance.

RESULTS

We enrolled 89 patients at baseline; 47 patients completed the end-of-study assessments. Although Pearson correlations showed that CRP and TGF-β1 levels were significantly, negatively associated with some memory indices, the results were not significant after correction. The GEE results, controlled for several confounding factors and multiple testing, showed that changes in TNF-α levels were negatively correlated with changes in the visual memory index (P = 0.01), and that changes in IL-6 levels were negatively correlated with changes in the verbal memory index (P = 0.009).

CONCLUSION

Memory performance, TNF-α, and IL-6 levels in OUD patients were negative correlated. Additional studies on regulating TNF-α and IL-6 expression to improve memory function in OUD patients might be warranted.

Cognitive function in patients with coronary artery disease: A literature review

Objective Cognitive function impairment is a well-documented complication of cerebrovascular disease (CBVD). Less is known about what factors affect the deterioration of cognitive function in patients with coronary artery disease (CAD). The aim of this review is to explore recent studies investigating factors associated with cognitive function in patients with CAD. Methods Studies published from 2010 to 2016 were identified through a systematic search of MEDLINE/PubMed and were included if they addressed factors affecting cognitive function in the CAD population. Results Of the 227 publications identified, 32 were selected for the review. Five factors tentatively affecting cognitive function in patients with CAD were identified: coronary artery bypass grafting (CABG) surgery, apolipoprotein E4 (APOE4) genotype, left ventricular ejection fraction (LVEF), medication use, and various hormones and biomarkers. Conclusion New techniques in CABG surgery have proven to alleviate postoperative cognitive decline. Researchers are still debating the effects of APOE4 genotype, LVEF, and the use of cardiovascular medications on cognitive function. Thyroid hormones and biomarkers are associated with cognitive function, but the exact nature of the association is debatable. Longitudinal studies should clarify those associations. In addition, cross-sectional studies addressing other causes of cognitive decline in patients with CAD are warranted.

Stress and aging act through common mechanisms to elicit neuroinflammatory priming

Over the course of an animal's lifespan, there is a protracted breakdown in basic homeostatic functions. Stressors (both psychological and physiological) can accelerate this process and compromise multiple homeostatic mechanisms. For example, both stress and aging can modulate neuroinflammatory function and cause a primed phenotype resulting in a heightened neuroinflammatory profile upon immune activation. Microglia, the brain's resident myeloid cell, produce "silent" immune machinery in response to stress and aging that does not cause immediate immune activation; rather, these changes prime the cell for a subsequent immune insult. Primed microglia exhibit a hyperinflammatory response upon immune activation that can exacerbate pathology. In this review, we will explore parallels between stress- and aging-induced neuroinflammatory priming. First, we will provide a background on the basic principles of neuroimmunology. Next, we will discuss evidence that neuroinflammatory responses become primed in the context of both stress and aging. We will also describe cell-specific contributions to neuroinflammatory priming with a focus on microglia. Finally, common mechanisms underlying priming in the context of stress and aging will be discussed: these mechanisms include glucocorticoid signaling; accumulation of danger signals; dis-inhibition of microglia; and breakdown of circadian rhythms. Overall, there are multifarious parallels between stress- and aging-elicited neuroinflammatory priming, suggesting that stress may promote a form of premature aging. Further unravelling mechanisms underlying priming could lead to improved treatments for buffering against stress- and aging-elicited behavioral pathologies.

Inflammatory markers in postoperative delirium (POD) and cognitive dysfunction (POCD): A meta-analysis of observational studies

Background

The aim of this study was to summarize and discuss the similarities and differences in inflammatory biomarkers in postoperative delirium (POD) and cognitive dysfunction (POCD).

Methods

A systematic retrieval of literature up to June 2017 in PubMed, Embase, the Cochrane Library, the China National Knowledge Infrastructure database, and the Wanfang database was conducted. Extracted data were analyzed with STATA (version 14). The standardized mean difference (SMD) and the 95% confidence interval (95% CI) of each indicator were calculated using a random effect model. We also performed tests of heterogeneity, sensitivity analysis, assessments of bias, and meta-regression in this meta-analysis.

Results

A total of 54 observational studies were included. By meta-analysis we found significantly increased C-reactive protein (CRP) (9 studies, SMD 0.883, 95% CI 0.130 to 1.637, P = 0.022 in POD; 10 studies, SMD -0.133, 95% CI -0.512 to 0.246, P = 0.429 in POCD) and interleukin (IL)-6 (7 studies, SMD 0.386, 95% CI 0.054 to 0.717, P = 0.022 in POD; 16 studies, SMD 0.089, 95% CI -0.133 to 0.311, P = 0.433 in POCD) concentrations in both POD and POCD patients. We also found that the SMDs of CRP and IL-6 from POCD patients were positively correlated with surgery type in the meta-regression (CRP: Coefficient = 1.555365, P = 0.001, 10 studies; IL-6: Coefficient = -0.6455521, P = 0.086, 16 studies).

Conclusion

Available evidence from medium-to-high quality observational studies suggests that POD and POCD are indeed correlated with the concentration of peripheral and cerebrospinal fluid (CSF) inflammatory markers. Some of these markers, such as CRP and IL-6, play roles in both POD and POCD, while others are specific to either one of them.

Interleukin-6 is both necessary and sufficient to produce perioperative neurocognitive disorder in mice

BACKGROUND

Perioperative neurocognitive disorders (PND) result in long-term morbidity and mortality with no effective interventions available. Because interleukin-6 (IL-6), a pro-inflammatory cytokine, is consistently up-regulated by trauma, including after surgery, we determined whether IL-6 is a putative therapeutic target for PND in a mouse model.

METHODS

Following institutional approval, adult (12-14 weeks) male C57/Bl6 mice were pretreated with the IL-6 receptor (IL6R) blocking antibody tocilizumab prior to open tibia fracture with internal fixation under isoflurane anaesthesia. Inflammatory and behavioural responses in a trace fear conditioning (TFC) paradigm were assessed postoperatively. Separately, the effects of IL-6 administration or of depletion of bone marrow-derived monocytes (BM-DMs) with clodrolip on the inflammatory and behavioural responses were assessed. Blood brain barrier disruption, hippocampal microglial activation, and infiltration of BM-DMs were each assessed following IL-6 administration.

RESULTS

The surgery-induced decrement in freezing time in the TFC assay, indicative of cognitive decline, was attenuated by tocilizumab (P<0.01). The surgery-induced increase in pro-inflammatory mediators was significantly reduced by tocilizumab. Exogenously administered IL-6 significantly impaired freezing behaviour (P<0.05) and up-regulated pro-inflammatory cytokines; both responses were prevented by depletion of BM-DMs. IL-6 disrupted the blood brain barrier, and increased hippocampal activation of microglia and infiltration of BM-DMs.

CONCLUSIONS

IL-6 is both necessary and sufficient to produce cognitive decline. Following further preclinical testing of its perioperative safety, the IL6R blocker tocilizumab is a candidate for prevention and/or treatment of PND.

Post-Operative Cognitive Dysfunction: An exploration of the inflammatory hypothesis and novel therapies

Post-Operative Cognitive Dysfunction (POCD) is a highly prevalent condition with significant clinical, social and financial impacts for patients and their communities. The underlying pathophysiology is becoming increasingly understood, with the role of neuroinflammation and oxidative stress secondary to surgery and anaesthesia strongly implicated. This review aims to describe the putative mechanisms by which surgery-induced inflammation produces cognitive sequelae, with a focus on identifying potential novel therapies based upon their ability to modify these pathways.

Ratio of β-amyloid protein (Aβ) and Tau predicts the postoperative cognitive dysfunction on patients undergoing total hip/knee replacement surgery

β-amyloid (Aβ) and Tau proteins are biomarkers of Alzheimer's disease neuropathogenesis. We hypothesized that they are also potential biomarkers for postoperative cognitive dysfunction (POCD). The present study was designed to evaluate the use of the Aβ-42/Tau ratio for the diagnosis of POCD in patients undergoing hip/knee replacement surgery. A total of 80 patients who underwent total hip/knee replacement surgery were grouped into POCD or non-POCD patients at 7 days, 1 and 3 months after surgery, according to a z-score recommended by the international study of POCD. Cerebrospinal fluid samples were collected prior to surgery and the concentration of Aβ-42 and Tau protein were detected. The ratio of Aβ-42/Tau was compared between the two groups at different time points. The patients completed the whole battery of neuropsychological tests following surgery. The POCD occurrence rates at 7 days, 1 and 3 months were 40, 25 and 15%, respectively. The Aβ-42/Tau ratios were much lower in the POCD group than those in the non-POCD group at 7 days (1.7±0.4 vs. 2.6±0.3), 1 month (1.6±0.5 vs. 2.4±0.4), and 3 months (1.6±0.4 vs. 2.5±0.4). The sensitivity and specificity for diagnosis of POCD as indicated by the ratios, at the three time points, were 91.7 vs. 81.2%, 86.7 vs. 70%, and 88 vs. 75.5%, respectively. The results show the incidence of POCD of patients aged at least 65 years who have undergone hip or knee fracture surgery gradually decrease as more patients recover. However, the Aβ-42/Tau ratio can be used in forecasting the occurrence of POCD elderly patients.

Cognitive decline after major oncological surgery in the elderly

BACKGROUND

Elderly patients undergoing oncological surgery experience postoperative cognitive decline. The aims of this study were to examine the incidence of cognitive decline 3 months after surgery and identify potential patient-, disease- and surgery-related risk factors for postoperative cognitive decline in onco-geriatric patients.

METHODS

A consecutive series of elderly patients (≥65 years) undergoing surgery for the removal of a solid tumour were included (n = 307). Cognitive performance was assessed pre-operatively and 3 months postoperatively. Postoperative decline was defined as a decline in scores of cognitive tests of ≥25% on ≥2 of 5 tests.

RESULTS

Of the patients who had completed the assessments, 117 (53%, 95% confidence interval [CI]: 47-60) had improved cognitive test scores, whereas 26 (12%, 95% CI: 7.6-16) showed cognitive decline at 3 months postoperatively. In patients aged >75 years, the incidence of overall cognitive decline 3 months postoperatively was 18% (95% CI: 9.3-27). In patients with lower pre-operative Mini-Mental State Examination (MMSE) score (≤26) the incidence was 37% (95% CI: 18-57), and in patients undergoing major surgery it was 18% (95% CI: 10.6-26). Of the cognitive domains, executive function was the most vulnerable to decline.

CONCLUSION

About half of the elderly patients show improvement in postoperative cognitive performance after oncological surgery, whereas 12% show cognitive decline. Advanced age, lower pre-operative MMSE score and major surgery are risk factors for cognitive decline at 3 months postoperatively and should be taken into account in the clinical decision-making progress. Research to develop interventions to preserve quality of life should focus on this high-risk subpopulation.

Postoperative Cognitive Dysfunction in the Elderly: A Review Comparing the Effects of Desflurane and Sevflurane

PURPOSE

The incidence of postoperative cognitive dysfunction (POCD) remains a relatively common complication in the elderly following surgery. Use of anesthesia for surgery might precipitate certain cognitive alterations. The purpose of this review is to address the impact of two volatile anesthetic agents, desflurane and sevoflurane, on POCD.

DESIGN

The focus of this review was on postoperative recovery and complications using two anesthetic agents.

METHODS

Several databases including PubMed and Cochrane were searched from the date of inception. The search words POCD, elderly, general anesthetics, desflurane, and sevoflurane were used and the search was limited to human, randomized clinical trials, and English.

FINDINGS

The findings show no difference in the emergence time between sevoflurane and desflurane and the incidence of POCD.

CONCLUSIONS

No definitive conclusion can be drawn about the type of anesthetic used and its relation to occurrence of POCD. However, the information presented is crucial, which can help to improve anesthetic usage and patient safety.

Influence of the postoperative inflammatory response on cognitive decline in elderly patients undergoing on-pump cardiac surgery: a controlled, prospective observational study

Background

The role of non-infective inflammatory response (IR) in the aetiology of postoperative cognitive dysfunction (POCD) is still controversial. The aim of this controlled, prospective observational study was to assess the possible relationship between the grade of IR, defined by procalcitonin (PCT) changes, and development of POCD related to cardiac surgery.

Methods

Forty-two patients, who were ≥ 60 years of age and scheduled for elective cardiac surgery, were separated into the low inflammatory (LIR) and high inflammatory (HIR) response groups based on their PCT levels measured on the first postoperative day. A matched normative control group of 32 subjects was recruited from primary care practice. The PCT and C-reactive protein (CRP) levels were monitored daily during the first five postoperative days. The cognitive function and mood state were preoperatively tested with a set of five neurocognitive tests and two mood inventories and at the seventh postoperative day. The Reliable Change Index modified for practice (RCIp) using data from normative controls was applied to determine the significant decline in test performance.

Results

The LIR (n = 20) and HIR (n = 22) groups differed significantly in the PCT (p < 0.001) but not in the CRP time courses. The incidence of POCD at the first postoperative week was 35.7% in the cohort. The LIR and HIR groups did not vary in the RCIp Z scores of neurocognitive tests and frequencies of POCD (7 vs 8 cases, respectively, p > 0.05). Additionally, there was no difference in the mood states, anxiety levels and perioperative parameters known to influence the development of POCD.

Conclusions

In this study, the magnitude of the non-infective inflammatory response generated by on-pump cardiac surgery did not influence the development of POCD in the early postoperative period in elderly patients.

A Prospective Evaluation of Systemic Biomarkers and Cognitive Function Associated with Carotid Revascularization

OBJECTIVE

To determine factors affecting cognition and identify predictors of long-term cognitive impairment following carotid revascularization procedures.

BACKGROUND

Cognitive impairment is common in older patients with carotid occlusive diseases.

METHODS

Patients undergoing carotid intervention for severe occlusive diseases were prospectively recruited. Patients received neurocognitive testing before, 1, and 6 months after carotid interventions. Plasma samples were also collected within 24 hours after carotid intervention and inflammatory cytokines were analyzed. Univariate and multivariate logistic regressions were performed to identify risk factors associated with significant cognitive deterioration (>10% decline).

RESULTS

A total of 98 patients (48% symptomatic) were recruited, including 55 patients receiving carotid stenting and 43 receiving endarterectomy. Mean age was 69 (range 54-91 years). Patients had overall improvement in cognitive measures 1 month after revascularization. When compared with carotid stenting, endarterectomy patients demonstrated postoperative improvement in cognition at 1 and 6 months compared with baseline. Carotid stenting (odds ratio 6.49, P = 0.020) and age greater than 80 years (odds ratio 12.6, P = 0.023) were associated with a significant long-term cognitive impairment. Multiple inflammatory cytokines also showed significant changes after revascularization. On multivariate analysis, after controlling for procedure and age, IL-12p40 (P = 0.041) was associated with a higher risk of significant cognitive impairment at 1 month; SDF1-α (P = 0.004) and tumor necrosis factor alpha (P = 0.006) were independent predictors of cognitive impairment, whereas interleukin-6 (P = 0.019) demonstrated cognitive protective effects at 6 months after revascularization.

CONCLUSIONS

Carotid interventions affect cognitive function. Systemic biomarkers can be used to identify patients at risk of significant cognitive decline postprocedures that benefit from targeted cognitive training.

Effects of ulinastatin on early postoperative cognitive function after one-lung ventilation surgery in elderly patients receiving neoadjuvant chemotherapy

We investigated the effects of ulinastatin on early postoperative cognitive dysfunction (POCD) after one-lung ventilation (OLV) surgery in elderly patients receiving neoadjuvant chemotherapy. Eighty elderly patients with preoperative neoadjuvant chemotherapy scheduling for radical esophagectomy under OLV were recruited. They were randomly divided into an ulinastatin pretreatment group (U group, n = 40) and a control group (C group, n = 40). The U group received 10,000 U/kg ulinastatin before anesthesia and 5000 U/kg daily on postoperative days 1 to 3, while C group received saline. Levels of interleukin (IL)-6, IL-10, C-reactive protein (CRP), and S-100β protein were assayed before surgery, at the end of surgery, and on postoperative days 1 and 3. Patients underwent cognitive assessment 1 day before and 7 days after surgery. 38 patients in U group and 37 patients in C group completed the neuropsychological tests. The U group had a lower incidence of POCD than C group (23.7 % versus 45.9 %, P = 0.043). The levels of S-100β protein, IL-6, IL-10, and CRP in both groups increased after surgery. The postoperative concentrations of S-100β protein, IL-6, and CRP in U group were lower than those in C group. On postoperative day 3, compared with C group, the level of CRP in U group was lower, while that of IL-10 was higher. These findings demonstrate that ulinastatin can attenuate the elevation of S100β protein levels and the incidence of POCD, most likely by the mechanism of reducing serum IL-6 and CRP levels and increasing IL-10 levels.

Independent Predictors of the Duration and Overall Burden of Postoperative Delirium After Cardiac Surgery in Adults: An Observational Cohort Study

OBJECTIVE

Postoperative delirium (POD) is a common complication after cardiac surgery and is associated with increased patient morbidity and mortality. The objective of this study was to identify risk factors for long duration and overall burden of POD after cardiac surgery.

DESIGN

One-year, single-center, retrospective, observational cohort study.

SETTING

University hospital.

PARTICIPANTS

Adult patients undergoing cardiac surgery with cardiopulmonary bypass in 2013.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patients were screened for POD using the Intensive Care Delirium Screening Checklist. The primary outcome measure was the incidence of POD. Secondary outcome measures were the duration of POD and the area under the curve determined using the Intensive Care Delirium Screening Checklist score over time. Independent predictors of POD were estimated in multivariable logistic regression models. Hospital length of stay, medications, and outcome data also were analyzed. Among the 656 patients included in the cohort, 618 were analyzed. The overall incidence of POD was 39%. Older patient age (odds ratio [95% confidence interval]) 1.06 [1.04-1.09] for an increase of 1 year, p < 0.001); low preoperative serum albumin (1.08 [1.03-1.13] for a decrease of 1 g/L, p < 0.001); a history of atrial fibrillation (2.30 [1.30-4.09], p = 0.004); perioperative stroke (6.27 [1.54-43.64], p = 0.008); ascending aortic replacement surgery (2.99 [1.50-6.05], p = 0.002); longer duration of procedure (1.37 [1.16-1.63] for an increase of 1 hour, p < 0.001); and increased postoperative C-reactive protein concentration (2.16 [1.49-3.16] for a 2-fold increase, p < 0.001) were associated with higher odds of POD. Among patients affected by POD, older age, perioperative stroke, longer procedure time, and increased postoperative C-reactive protein were consistently predictive of longer duration of POD and greater area under the curve.

CONCLUSIONS

Known risk factors for the development of POD after cardiac surgery also are predictive of prolonged duration and high overall burden of POD.

Pathogenesis and treatment of post-operative cognitive dysfunction

Cognitive disorders common in the post-operative period, are the post-operative delirium (POD) and the post-operative cognitive dysfunction (POCD). The Diagnostic and Statistical Manual of Mental Disorders (DSM) does not mention POCD as a separate disease entity, and thus little is known about the pathogenesis of this disorder. The aim of this study was to review, detect and highlight the most important data cited, regarding pathogenesis mechanisms and treatment of the post-operative cognitive dysfunction (POCD). The study was carried out from March 2015 to June 2015. Literature review was achieved by searching a number of bibliographic databases including PubMed, Google Scholar and SCOPUS, surveying published articles from 1955 to 2014. As far as the selection criteria, the material consists of scientific articles published mainly over the last fifteen years, while material published before 2000 was selected because it was considered to be important. This review showed that deficits are observed in one or more discrete areas of the patient's mental state, such as attention, concentration, memory, psychomotor speed and more. This condition is usually developed over a period of more than a week or month after surgery and is more common in elderly patients. Mechanisms that have been proposed to explain this phenomenon are hyperventilation, hypotension, cerebral microemboli and inflammatory mechanisms. Its differential diagnosis will be made mainly from delirium. POCD treatment will first include the exclusion of any other serious diseases that can cause organic psychosyndrome and then focus on the actual symptoms.

Peripheral surgical wounding may induce cognitive impairment through interlukin-6-dependent mechanisms in aged mice

Post-operative cognitive dysfunction (POCD) is associated with morbidity, mortality and increased cost of medical care. However, the neuropathogenesis and targeted interventions of POCD remain largely to be determined. We have found that the peripheral surgical wounding induces an age-dependent Aβ accumulation, neuroinflammation and cognitive impairment in aged mice. Pro-inflammatory cytokine interlukin-6 (IL-6) has been reported to be associated with cognitive impairment in rodents and humans. However, the role of IL-6 in the neuropathogenesis of POCD is unknown. We therefore employed pharmacological (IL-6 antibody) and genetic (knockout of IL-6) approach to investigate whether IL-6 contributed to the peripheral surgical wounding-induced cognitive impairment in aged mice. Abdominal surgery under local anesthesia (peripheral surgical wounding) was established in 18-month-old wild-type and IL-6 knockout mice (n = 6 to 10 in each group). Brain level of IL-6 and cognitive function in the mice were determined by western blot, ELISA at the end of procedure, and Fear Conditioning System at 7 days after the procedure. The peripheral surgical wounding increased the level of IL-6 in the hippocampus of aged wild-type, but not IL-6 knockout mice. IL-6 antibody ameliorated the peripheral surgical wounding-induced cognitive impairment in the aged wild-type mice. Finally, the peripheral surgical wounding did not induce cognitive impairment in the aged IL-6 knockout mice. These data suggested that IL-6 would be a required pro-inflammatory cytokine for the peripheral surgical wounding-induced cognitive impairment. Given this, further studies are warranted to investigate the role of IL-6 in the neuropathogenesis and targeted interventions of POCD.

The Post-Anaesthesia N-acetylcysteine Cognitive Evaluation (PANACEA) trial: study protocol for a randomised controlled trial

Background

Some degree of cognitive decline after surgery occurs in as many as one quarter of elderly surgical patients, and this decline is associated with increased morbidity and mortality. Cognition may be affected across a range of domains, including memory, psychomotor skills, and executive function. Whilst the exact mechanisms of cognitive change after surgery are not precisely known, oxidative stress and subsequent neuroinflammation have been implicated. N-acetylcysteine (NAC) acts via multiple interrelated mechanisms to influence oxidative homeostasis, neuronal transmission, and inflammation. NAC has been shown to reduce oxidative stress and inflammation in both human and animal models. There is clinical evidence to suggest that NAC may be beneficial in preventing the cognitive decline associated with both acute physiological insults and dementia-related disorders. To date, no trials have examined perioperative NAC as a potential moderator of postoperative cognitive changes in the noncardiac surgery setting.

Methods and design

This is a single-centre, randomised, double-blind, placebo-controlled clinical trial, with a between-group, repeated-measures, longitudinal design. The study will recruit 370 noncardiac surgical patients at the University Hospital Geelong, aged 60 years or older. Participants are randomly assigned to receive either NAC or placebo (1:1 ratio), and groups are stratified by age and surgery type. Participants undergo a series of neuropsychological tests prior to surgery, 7 days, 3 months, and 12 months post surgery. It is hypothesised that the perioperative administration of NAC will reduce the degree of postoperative cognitive changes at early and long-term follow-up, as measured by changes on individual measures of the neurocognitive battery, when compared with placebo. Serum samples are taken on the day of surgery and on day 2 post surgery to quantitate any changes in levels of biomarkers of inflammation and oxidative stress.

Discussion

The PANACEA trial aims to examine the potential efficacy of perioperative NAC to reduce the severity of postoperative cognitive dysfunction in an elderly, noncardiac surgery population. This is an entirely novel approach to the prevention of postoperative cognitive dysfunction and will have high impact and translatable outcomes if NAC is found to be beneficial.

Trial registration

The PANACEA trial has been registered with the Therapeutic Goods Administration, and the Australian New Zealand Clinical Trials Registry: ACTRN12614000411640; registered on 15 April 2014.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1529-4) contains supplementary material, which is available to authorized users.