Postoperative Delirium and Postoperative Cognitive Dysfunction: Overlap and Divergence

Mitophagy in perioperative neurocognitive disorder: mechanisms and therapeutic strategies

Perioperative neurocognitive disorder (PND) is a common neurological complication after surgery/anesthesia in elderly patients that affect postoperative outcome and long-term quality of life, which increases the cost of family and social resources. The pathological mechanism of PND is complex and not fully understood, and the methods of prevention and treatment of PND are very limited, so it is particularly important to analyze the mechanism of PND. Research indicates that mitochondrial dysfunction is pivotal in the initiation and progression of PND, although the precise mechanisms remain elusive and could involve disrupted mitophagy. We reviewed recent studies on the link between mitophagy and PND, highlighting the role of key proteins in abnormal mitophagy and discussing therapeutic strategies aimed at mitophagy regulation. This provides insights into the mechanisms underlying PND and potential therapeutic targets.

Intelligent Medical Assessment of the Impact of Anesthesia and Sedation Depth on Cognitive Function after Gynecological Laparoscopic Surgery

In recent years, the research on post operational cognitive dysfunction (POCD) has received increasing attention. Some patients may experience complications such as mental disorder and memory impairment after gynecological laparoscopic surgery, which are cognitive, social, and personality issues of postoperative patients. This article divided patients after gynecological laparoscopic surgery into three groups based on different BIS (biological index) ranges. Before clinical use, artificial intelligence was used to sort out patients' complete history records, physical examination and analyze laboratory examination results, so as to determine the anesthetic dose and depth and reduce the incidence of accidents during surgery. This article adopted a combination of midazolam propofol radiocuronium bromide general anesthesia to adjust blood targeted concentration and maintain the depth of general anesthesia for patients. Using POCD as a starting point, the occurrence of POCD after gynecological laparoscopic surgery was evaluated through preoperative and postoperative neuropsychological measurements on the 14th day, as well as MMSE (Minimal State Examination) scores, and the impact of different anesthesia depths on POCD was also explored, which can provide a theoretical basis for the prevention and treatment of POCD. The MMSE score of Group A patients on the day before anesthesia was 23.9, while the MMSE score of Group B patients on the day before anesthesia was 23.8. The application of intelligent medicine in the study of the impact of anesthesia and sedation depth on gynecological laparoscopic surgery can improve the safety of surgery and the quality of life of patients, and has an important promoting role in clinical practice. The innovation of the research in this paper lies in the use of intelligent medical technology, through neuropsychological testing and MMSE scoring, in-depth analysis of the relationship between anesthesia depth and POCD.Combined anesthesia with midazolam and propofol was used, and the depth of anesthesia was precisely adjusted according to the BIS value.The study found that shallow anesthesia (low BIS value) may reduce the incidence of POCD, which provides theoretical and practical guidance for optimizing anesthesia strategies.

TREM2 Modulates Postoperative Cognitive Function in Aged Mice by Inhibiting the NLRP3/caspase-1 Pathway and Apoptosis via PLCγ2 Activation

Postoperative cognitive dysfunction (POCD) is a prevalent complication in elderly patients, with neuroinflammation identified as a key contributing factor. This study investigates the therapeutic potential of the TREM2-PLCγ2 signaling pathway in mitigating neuroinflammation, neuronal apoptosis and cognitive impairment following surgery. We employed both in vivo and in vitro models to investigate the effects of TREM2 activation and its interaction with PLCγ2. Mice subjected to surgery were pre-treated with the TREM2-activating peptide COG1410, and subsequently evaluated for neuroinflammation, neuronal apoptosis, and cognitive function. In vitro studies using microglial cells were conducted to examine the mechanistic relationship between TREM2 and PLCγ2 phosphorylation via SYK. Knockdown experiments and SYK inhibition were performed to determine the hierarchical interaction between TREM2, PLCγ2, and their downstream influence on the NLRP3 inflammasome. Surgery significantly elevated the activation of the NLRP3 inflammasome, along with increased Cleaved Caspase-1, IL-1β, IL-18, and neuronal apoptosis markers. Pre-treatment with COG1410 effectively reduced these pro-inflammatory and pro-apoptotic markers, while alleviating cognitive impairment. TREM2 activation promoted SYK-dependent phosphorylation of PLCγ2, which inhibited NLRP3 inflammasome activation and reduced neuroinflammation. TREM2 knockdown exacerbated microglial inflammation, while PLCγ2 knockdown suppressed NLRP3 activation. Inhibition of SYK impaired the protective effects of the TREM2-PLCγ2 pathway and delayed cognitive recovery in mice. RNA-sequencing further revealed significant alterations in pathways related to neuroinflammation and apoptosis. TREM2 modulates PLCγ2 activity through SYK phosphorylation, thereby alleviating microglial-driven neuroinflammation and neuronal apoptosis, and improving cognitive impairment following surgery. Targeting the TREM2-PLCγ2 pathway presents a promising strategy for the prevention and treatment of POCD.

Metformin activates the PI3K/AKT/BDNF axis to attenuate postoperative cognitive dysfunction

Postoperative cognitive dysfunction (POCD) is a prevalent neurocognitive complication of anesthesia and surgery. Metformin, a widely used antidiabetic drug, has neuroprotective properties and improves cognitive impairment and memory deficits. However, the mechanisms underlying its action in improving cognitive dysfunction after anesthesia and surgery remain unclear. This study aimed to explore the effects of metformin on POCD and the underlying mechanisms at play. We established an in vivo POCD model using isoflurane inhalation anesthesia with exploratory laparotomy. We found that pretreatment with metformin significantly improved cognitive function and anxiety-like behaviors in mice. Additionally, metformin attenuated the impairment of synaptic plasticity induced by POCD and restored levels of synaptic proteins and dendritic density in the hippocampus. Furthermore, metformin attenuated neuroinflammation by downregulating the expression of interleukin (IL)-6, IL-1β, and tumor necrosis factor-α, and reducing neuronal apoptosis. It also activates the PI3K/AKT signaling pathway, resulting in increased expression of brain-derived neurotrophic factor (BDNF). Finally, the PI3K inhibitor, LY294002, reversed the effects of metformin on the levels of PI3K, AKT phosphorylation, and BDNF in vitro cultured HT-22 cells. Additionally, in an in vivo model of POCD, it was observed that cognitive function in mice was significantly suppressed by treatment with the PI3K inhibitor LY294002. These results reveal that metformin may alleviate POCD by modulating the PI3K/AKT/BDNF axis. Our study may provide a novel strategy for preventing and treating POCD with this medication.

Peripheral blood mononuclear cell transcriptomic trajectories reveal dynamic regulation of inflammatory actors in delirium

Delirium is a neurologic syndrome characterized by inattention and cognitive impairment frequently encountered in the medically ill. Peripheral inflammation is a key trigger of delirium, but the patient-specific immune responses associated with delirium development and resolution are unknown. This retrospective cohort study of prospectively collected biospecimens examines RNA sequencing from peripheral blood mononuclear cells of adults hospitalized for COVID-19 to better understand patient-specific factors associated with delirium (n = 64). Longitudinal transcriptomic analyses highlight persistent immune dysregulation in delirium, marked by increasing expression trajectories of genes linked to innate immune pathways, including complement activation, cytokine production, and monocyte/macrophage recruitment. Genes involved adaptive immunity showed a declining trajectory over time in patients with delirium. Although corticosteroid treatment suppressed some aspects of immune hyperactivation, aberrant responses contributing to delirium were exacerbated. Delirium resolution was characterized by normalization of key transcripts such as CCL2 and innate immune markers. Novel associations with delirium were found in genes related to stress granule assembly and DUSP2 and KLF10, which mediate T-cell responses. These findings provide insights into the peripheral immune responses accompanying delirium and their modulation by corticosteroids. Future trials targeting aberrant inflammatory responses may mitigate the severe outcomes associated with delirium due to COVID19.

Association of post-stroke delirium with short-term trajectories of cognition

BACKGROUND

Delirium could increase the risk of cognitive decline. We aimed to determine if changes in cognitive functions shortly after stroke differ between patients with and patients without delirium.

METHODS

We included patients who participated in the Prospective Observational Polish Study on post-stroke delirium and underwent the Montreal Cognitive Assessment (MoCA) at day 1, day 8 and 3 months after stroke. Delirium was diagnosed using DSM-5 criteria. We used mixed linear regression models to characterize changes in mean adjusted MoCA scores over time.

RESULTS

We included 402 patients (mean age: 68.9 ± 13.3 years; mean NIHSS on admission: 6.2 ± 5.5; 48.8 % female). Delirium occurred in 18.9 % of them. Mean adjusted MoCA scores increased from day 1 to day 8 (20.48 vs 23.34, P < 0.001) and then declined from day 8 to month 3 (23.34 vs 22.21, P < 0.001). The rate of change in total MoCA scores from day 1 to day 8 (net effect: 0.65, 95 %CI: -1.19; 2.49, P = 0.489) and from day 8 to month 3 (net effect: -2.43, 95 %CI: -4.84; -0.02, P = 0.147) did not differ between patients with and patients without delirium. Compared with patients without delirium, those with delirium showed a greater improvement in naming, orientation and attention, accompanied by a worsening in memory from day 1 to day 8. They also experienced a greater decline in attention and orientation, along with a greater improvement in memory from day 8 to 3 months.

CONCLUSIONS

Post-stroke delirium is associated with short-term trajectories of specific cognitive domains, but not with changes in global cognition.

Role of Microglial Mitophagy in Alleviating Postoperative Cognitive Dysfunction: a Mechanistic Study

Postoperative cognitive dysfunction (POCD), a common complication following anesthesia and surgery, is influenced by hippocampal neuroinflammation and microglial activation. Mitophagy, a process regulating inflammatory responses by limiting the accumulation of damaged mitochondria, plays a significant role. This study aimed to determine whether regulating microglial mitophagy and the cGAS-STING pathway could alleviate cognitive decline after surgery. Exploratory laparotomy was performed to establish a POCD model using mice. Western blotting, immunofluorescence staining, transmission electron microscopy, and mt-Keima assays were used to examine microglial mitophagy and the cGAS-STING pathway. Quantitative polymerase chain reaction (qPCR) was used to detect inflammatory mediators and cytosolic mitochondrial DNA (mtDNA) levels in BV2 cells. Exploratory laparotomy triggered mitophagy and enhanced the cGAS-STING pathway in mice hippocampi. Pharmacological treatment reduced microglial activation, neuroinflammation, and cognitive impairment after surgery. Mitophagy suppressed the cGAS-STING pathway in mice hippocampi. In vitro, microglia-induced inflammation was mediated by mitophagy and the cGAS-STING pathway. Small interfering RNA (siRNA) of PINK1 hindered mitophagy activation and facilitated the cytosolic release of mtDNA, resulting in the initiation of the cGAS-STING pathway and innate immune response. Microglial mitophagy inhibited inflammatory responses via the mtDNA-cGAS-STING pathway inducing microglial mitophagy and inhibiting the mtDNA-cGAS-STING pathway may be an effective therapeutic approach for patients with POCD.

Effect of parecoxib on postoperative cognitive function and analgesic safety in elderly patients undergoing gastrointestinal tumor resection: A retrospective study

Neuroinflammation is associated with the development of postoperative cognitive dysfunction (POCD). Parecoxib has powerful anti-inflammatory and analgesic effects, which may reduce the occurrence of POCD. We hypothesized that parecoxib could reduce the incidence of POCD and relieve postoperative pain without increasing postoperative complications in elderly patients with gastrointestinal cancer. The study analyzed the effect of parecoxib on elderly patients undergoing elective radical resection of gastrointestinal tumors. Patients were divided into the NSAIDs group and the non-NSAIDs group according to whether parecoxib was administered. Demographic and clinical data were collected and compared. The incidence of POCD was set as the primary outcome, and postoperative pain as the secondary outcome. Among the 440 enrolled patients, the POCD incidence rates within 7 days after surgery in the NSAIDs and non-NSAIDs groups were 42.60% and 40.30%, respectively, with no statistically significant difference (P > 0.05). Patients in the NSAIDs group experienced significantly less pain on the first and second days after surgery compared to the non-NSAIDs group (P < 0.05). There were no statistically significant differences in postoperative adverse events between the two groups (P > 0.05). Parecoxib had no significant negative effect on early postoperative cognitive function, effectively alleviating early postoperative acute pain without increasing postoperative complications. The findings have implications for the broader use of parecoxib in postoperative pain management in elderly patients undergoing major surgery.

Red light-induced localized release of carbon monoxide for alleviating postoperative cognitive dysfunction

Inflammation within the central nervous system (CNS), which may be triggered by surgical trauma, has been implicated as a significant factor contributing to postoperative cognitive dysfunction (POCD). The relationship between mitigating inflammation at peripheral surgical sites and its potential to attenuate the CNS inflammatory response, thereby easing POCD symptoms, remains uncertain. Notably, carbon monoxide (CO), a gasotransmitter, exhibits pronounced anti-inflammatory effects. Herein, we have developed carbon monoxide-releasing micelles (CORMs), a nanoparticle that safely and locally liberates CO upon exposure to 650 nm light irradiation. In a POCD mouse model, treatment with CORMs activated by light (CORMs + hv) markedly reduced the concentrations of interleukin (IL)-6, IL-1β, and tumor necrosis factor-alpha (TNF-α) in both the peripheral blood and the hippocampus, alongside a decrease in ionized calcium-binding adapter molecule 1 in the hippocampal CA1 region. Furthermore, CORMs + hv treatment diminished Evans blue extravasation, augmented the expression of tight junction proteins zonula occludens-1 and occludin, enhanced neurocognitive functions, and fostered fracture healing. Bioinformatics analysis and experimental validation has identified Htr1b and Trhr as potential key regulators in the neuroactive ligand-receptor interaction signaling pathway implicated in POCD. This work offers new perspectives on the mechanisms driving POCD and avenues for therapeutic intervention.

Perioperative approaches to prevent delayed neurocognitive recovery and postoperative neurocognitive disorder in older surgical patients: A systematic review and meta-analysis of randomized controlled trials

Background and Aims

Delayed neurocognitive recovery (DNR) and postoperative neurocognitive disorder (P-NCD) are common postoperative complications affecting older patients. This review evaluates perioperative approaches for preventing DNR and P-NCD in older noncardiac surgical patients.

Material and Methods

We searched databases for relevant articles from inception through June 2022 and updated in May 2023 (PROSPERO ID CRD42022359289). Randomized controlled trials (RCTs) utilizing intervention for DNR and/or P-NCD were included.

Results

We included 39 RCTs involving anesthetic (25 RCTs, 7422 patients) and other pharmacological and nonpharmacological approaches (14 RCTs, 2210 patients). Seventeen trials investigating four interventions were included in the meta-analysis for DNR. Perioperative dexmedetomidine (relative risk [RR]: 0.59, 95% confidence interval [CI]: 0.35-0.97; P = 0.04) and propofol-based total intravenous anesthesia (TIVA) (RR: 0.81, 95% CI: 0.66-0.98; P = 0.03) significantly decreased the risk of DNR versus control. There was no significant decrease in the risk of DNR with regional anesthesia (RA) versus general anesthesia (GA) (RR: 0.89, 95% CI: 0.63-1.26) or bispectral index (BIS) monitoring (RR: 0.79, 95% CI: 0.60-1.04) versus the control groups. Evidence regarding the effects of interventions on P-NCD is limited. Although all included trials were at low risk of bias, the quality of meta-analysis pooled estimates was low.

Conclusions

Our meta-analysis of RCTs showed that dexmedetomidine and TIVA decrease the risk of DNR in older patients undergoing noncardiac surgery by 41% and 20%, respectively, versus control. Further RCTs of adequate power and methodology on the effects of interventions on DNR and P-NCD are warranted.

Intraoperative hypotension and postoperative delirium in elderly male patients undergoing laryngectomy: a single-center retrospective cohort study

BACKGROUND

Postoperative delirium (POD) is a common, transient postoperative cognitive dysfunction in elderly patients. The relationship between POD and intraoperative hypotension remains unclear. This study aims to determine if intraoperative hypotension predicts POD in elderly male patients undergoing laryngectomy.

METHODS

This study included male patients over 65 years old who underwent laryngectomy between April 2018 and January 2022. The Confusion Assessment Method (CAM) was used to diagnose delirium. Intraoperative hypotension was defined as a Mean Arterial Pressure (MAP) during surgery that was less than 30% of the preoperative level for at least 30 minutes. The relationship between intraoperative hypotension and POD incidence was adjusted for patient demographics and surgery-related factors.

RESULTS

Out of 428 male patients, 77 (18.0%) developed POD, and 166 (38.8%) experienced intraoperative hypotension. Surgery duration ≥ 300 minutes (OR = 1.873, 95% CI 1.041-3.241, p = 0.036), intraoperative hypotension (OR = 1.739, 95% CI 1.039-2.912, p = 0.035), and schooling (OR = 2.655, 95% CI 1.338-5.268) were independent risk factors for POD. The association between intraoperative hypotension and POD was significantly influenced by surgery duration (p for interaction = 0.008), with a stronger association in prolonged surgeries (adjusted OR = 4.902; 95% CI 1.816-13.230).

CONCLUSIONS

Intraoperative hypotension and low education level are associated with an increased risk of POD in elderly male patients undergoing laryngectomy, especially with prolonged surgery duration.

Postoperative cognitive dysfunction: Review of pathophysiology, diagnostics and preventive strategies

Postoperative cognitive impairment is a common disorder after major surgery. Advances in medicine and treatment have resulted in an increasingly ageing population undergoing major surgical procedures. Since age is the most important risk factor for postoperative cognitive decline, it is not surprising that impairment of cognitive functions after surgery was recorded in almost a third of elderly patients. Postoperative cognitive dysfunction is part of the spectrum of postoperative cognitive impairment and researchers often confuse it with postoperative delirium and delayed neurocognitive recovery. This is the cause of great differences in the results of research that is focused on the incidence and possible prevention of postoperative cognitive dysfunction. In this review, we focused on current recommendations for a uniform nomenclature of postoperative cognitive impairment and diagnosis of postoperative cognitive dysfunction, the presumed pathophysiology of postoperative cognitive dysfunction and recommendations for its treatment and possible prevention strategies.

Assessment of cognitive function after surgery for colorectal cancer-a scoping review

OBJECTIVE

Colorectal cancer is primarily treated with surgery. Major surgery and older age are risk factors associated with postoperative decline in cognitive function. In clinical research, a wide range of instruments have been used to assess cognitive function. There are no clear criteria for the measurement of postoperative cognitive dysfunction. This scoping review aimed to map how and when cognitive function has been assessed after surgery for colorectal cancer and the reported incidence of postoperative cognitive decline.

DESIGN

Systematic scoping review following the JBI approach.

DATA SOURCES

Scopus and PubMed. Last search January 2023.

ELIGIBILITY CRITERIA

Reports with outcomes of postoperatively assessed cognitive function in colorectal cancer patients with first assessment within 1 year of surgery were included.

DATA EXTRACTION AND SYNTHESIS

Data were extracted by one researcher and controlled for accuracy by a second researcher. Data were summarised in tables and charts.

RESULTS

In total, 49 reports were included (16 clinical trials, 33 cohort studies). Cognitive function was assessed with patient-reported outcome measures, clinical screening tools, neurophysiological testing and complication classification. The definition was most often related to the specific instrument, as predefined cut-off or change from baseline. Assessments were performed between 1 hour and 36 months after surgery-few reports included follow-up both within and after 30 days postoperatively. Incidence of cognitive decline varied considerably (0%-64%), depending on the instrument, definition criteria and time of assessment. Most studies reported a decline in cognitive function after surgery with recovery during follow-up.

CONCLUSIONS

This study showed a heterogeneity in the choice of assessment method and measurement criteria for cognitive dysfunction after colorectal cancer surgery. A more unified measurement approach in further research would be beneficial to evaluate postoperative cognitive function and understand its impact on the daily lives of patients with colorectal cancer.

TRIAL REGISTRATION NUMBER

10.17605/OSF.IO/2M3DT.

Brain health: A concern for anaesthesiologists and intensivists

Damage to the brain can have disastrous and long-lasting consequences. The European Society of Anaesthesiology and Intensive Care (ESAIC) is aware of the importance of taking good care of the brain, both of patients and of anaesthesia and intensive care unit (ICU) caregivers, and has organised a complete learning track on brain health to bring this concern to the attention of practitioners. This learning track included an online Focus Meeting on Brain Health (November 25, 2023). We here provide readers with a digest of the information that was delivered during that meeting in an opinion paper driven by the authors' own reading of the literature. It is divided according to the meeting's sessions, including how to improve the health of an injured brain, how to keep a young or old brain healthy, how to keep a healthy adult brain unimpaired, how monitoring can impact brain health in the operating room and in the intensive care unit, and how to keep the anaesthesia and ICU caregivers' brain healthy. Each part is a brief and focused summary. The main delivered messages are that the management of injured brain patients involves an adequate choice of sedation, adequate brain monitoring, and focused attention to specific points depending on the underlying pathology; that several measures can be undertaken to protect the brain of the very young needing anaesthesia; that it is possible to detect older patients at risk of postoperative neurocognitive disorders, and that dedicated perioperative management by a multidisciplinary expert team may improve their outcomes; that apparently healthy adult brains may suffer during anaesthesia; that the electroencephalogram may track peri-operative brain dysfunction, and that female patients should be given special care in this respect; that multimodal brain monitoring helps to detect pathological processes and to maintain brain homeostasis; and that burnout in anaesthesiologists can be effectively fought using personal, organisational, managerial and legal approaches.

Effect of desflurane, sevoflurane or propofol on the incidence of postoperative delirium in older adults undergoing moderate- to high-risk major non-cardiac surgery: study protocol for a prospective, randomised, observer-blinded, clinical trial (RAPID-II trial)

INTRODUCTION

The effect of different anaesthetics on the incidence of postoperative delirium is still not entirely clear. Therefore, we will evaluate the effect of desflurane versus sevoflurane versus propofol for the maintenance of anaesthesia on the incidence of postoperative delirium in older adults undergoing moderate- to high-risk major non-cardiac surgery. We will further compare the incidences of delayed neurocognitive recovery, long-term postoperative neurocognitive disorder, postoperative nausea and vomiting between the groups.

METHODS AND ANALYSIS

In this multicentre, prospective, observer-blinded, randomised controlled clinical trial, we will include 1332 patients ≥65 years of age undergoing moderate- to high-risk major non-cardiac surgery lasting at least 2 hours. Patients will be randomly 1:1:1 assigned to receive desflurane, sevoflurane or propofol for anaesthesia. Maintenance of anaesthesia will be performed in a goal-directed manner using processed electroencephalography with an intraoperative goal of bispectral index 40-60. Our primary outcome will be the incidence of postoperative delirium within the first five postoperative days. Postoperative delirium will be assessed using the three-dimensional-confusion assessment method (3D-CAM) or CAM-intensive care unit (ICU) in the morning and evening of the first five postoperative days by blinded study personnel. The primary outcome, the incidence of postoperative delirium, will be compared between the three study groups using a χ2 test. Furthermore, a logistic regression model for the incidence of postoperative delirium will be performed, accounting for randomised groups as well as other predefined confounding factors.

ETHICS AND DISSEMINATION

This clinical trial has been approved by the ethics committee and the Federal Office for Safety in Healthcare as the competent authority for clinical trials in Austria. The results of this trial will be published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT05990790.

A Prospective Observational Cohort Study of Language Preference and Preoperative Cognitive Screening in Older Adults: Do Language Disparities Exist in Cognitive Screening and Does the Association Between Test Results and Postoperative Delirium Differ Based on Language Preference?

BACKGROUND

A greater percentage of surgical procedures are being performed each year on patients 65 years of age or older. Concurrently, a growing proportion of patients in English-speaking countries such as the United States, United Kingdom, Australia, and Canada have a language other than English (LOE) preference. We aimed to measure whether patients with LOE underwent cognitive screening at the same rates as their English-speaking counterparts when routine screening was instituted. We also aimed to measure the association between preoperative Mini-Cog and postoperative delirium (POD) in both English-speaking and LOE patients.

METHODS

We conducted a single-center, observational cohort study in patients 65 years old or older, scheduled for surgery and evaluated in the preoperative clinic. Cognitive screening of older adults was recommended as an institutional program for all patients 65 and older presenting to the preoperative clinic. We measured program adherence for cognitive screening. We also assessed the association of preoperative impairment on Mini-Cog and POD in both English-speaking and LOE patients, and whether the association differed for the 2 groups. A Mini-Cog score ≤2 was considered impaired. Postoperatively, patients were assessed for POD using the Confusion Assessment Method (CAM) and by systematic chart review.

RESULTS

Over a 3-year period (February 2019-January 2022), 2446 patients 65 years old or older were assessed in the preoperative clinic prior. Of those 1956 patients underwent cognitive screening. Eighty-nine percent of English-speaking patients underwent preoperative cognitive screening, compared to 58% of LOE patients. The odds of having a Mini-Cog assessment were 5.6 times higher (95% confidence interval [CI], 4.6-7.0) P < .001 for English-speaking patients compared to LOE patients. In English-speaking patients with a positive Mini-Cog screen, the odds of having postop delirium were 3.5 times higher (95% CI, 2.6-4.8) P < .001 when compared to negative Mini-Cog. In LOE patients, the odds of having postop delirium were 3.9 times higher (95% CI, 2.1-7.3) P < .001 for those with a positive Mini-Cog compared to a negative Mini-Cog. The difference between these 2 odds ratios was not significant ( P = .753).

CONCLUSIONS

We observed a disparity in the rates LOE patients were cognitively screened before surgery, despite the Mini-Cog being associated with POD in both English-speaking and LOE patients. Efforts should be made to identify barriers to cognitive screening in limited English-proficient older adults.

Functional role of lncRNA MEG3 on pyroptosis through interacting with EZH2 and YTHDC1 in postoperative cognitive dysfunction

BACKGROUND

The molecular biology mechanisms underlying postoperative cognitive dysfunction (POCD) remain unclear, resulting in a lack of specific therapeutic targets and limited clinical treatment options. The NLRP3 pyroptotic pathway, induced by neuroinflammation, is known to promote the development of POCD. Research has shown that lncRNA MEG3 exacerbates cell pyroptosis in various neurological injuries, though the precise mechanism remains to be investigated.

METHODS

In vitro and in vivo models of POCD were established through treatment with sevoflurane. Gene and protein expression were investigated using qRT-PCR, Western blot analysis, ELISA, and histological staining. Additionally, cell viability and injury were assessed through CCK-8 and LDH assays. Hippocampal-dependent memory and cognitive abilities were evaluated using the Morris Water Maze (MWM) test. Furthermore, the interactions between MEG3 and EZH2/YTHDC1 were validated through RNA immunoprecipitation (RIP) and chromatin immunoprecipitation (ChIP).

RESULTS

Our findings reveal that sevoflurane significantly reduced MEG3 and pyroptosis-related proteins in mice. The overexpression of MEG3 protected mice against sevoflurane-induced cognitive dysfunction and reversed sevoflurane-induced pyroptosis in hippocampal neurons. MEG3 induced the downregulation of NLRP3 expression and reduced mRNA stability through its interaction with EZH2/YTHDC1.

CONCLUSION

In conclusion, our study elucidates that MEG3 inhibits the NLRP3 inflammasome and hippocampal neuron pyroptosis through the recruitment of EZH2/YTHDC1. These findings shed light on the underlying mechanism of MEG3 in the regulation of POCD and suggest that MEG3 could serve as a potential therapeutic target for the treatment of POCD.

The association of pre-operative biomarkers of endothelial dysfunction with the risk of post-operative neurocognitive disorders: results from the BioCog study

INTRODUCTION

Endothelial dysfunction (ED) promotes the development of atherosclerosis, and studies suggest an association with age-related neurocognitive disorders. It is currently unclear whether ED is also associated with the risk of perioperative neurocognitive disorders.

METHOD

We included 788 participants aged ≥ 65 years of the BioCog study. Patients were scheduled to undergo elective surgery with expected duration > 60 min. Blood was collected before surgery for measurement of 5 biomarkers of ED: asymmetric and symmetric dimethylarginine (ADMA; SDMA), intercellular and vascular adhesion molecule (ICAM-1, VCAM-1), and von Willebrand factor (vWF). Patients were monitored for the occurrence of postoperative delirium (POD) daily until the 7th postoperative day. 537 (68.1%) patients returned for a 3-month follow-up. Post-operative cognitive dysfunction (POCD) was defined from the change in results on a battery of 6 neuropsychological tests between baseline and 3 months, compared to the change in results of a control group during the 3-month interval. The associations of each of the 5 ED biomarkers with POD and POCD respectively were determined using multiple logistic regression analyses with adjustment for age, sex, surgery type, pre-morbid IQ, body mass index, hypertension, diabetes, HbA1C, triglyceride, total and HDL cholesterol.

RESULTS

19.8% of 788 patients developed POD; 10.1% of 537 patients had POCD at 3 months. Concentrations of ED biomarkers were not significantly associated with a POD. A higher VCAM-1 concentration was associated with a reduced POCD risk (adjusted odds ratio 0.55; 95% CI: 0.35-0.86). No further statistically significant results were found.

CONCLUSION

Pre-operative concentrations of ED biomarkers were not associated with POD risk. We unexpectedly found higher VCAM-1 to be associated with a reduced POCD risk. Further studies are needed to evaluate these findings.

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

BACKGROUND

Postoperative neurocognitive disorders (PNDs) frequently occur following orthopedic surgery and are closely associated with adverse prognosis. PNDs are an emerging concept that includes both postoperative cognitive dysfunction (POCD) and postoperative delirium (POD). The prevention of combined use of peripheral nerve block (PNB) and general anesthesia (GA) on POCD and/or POD incidence following orthopedic surgery remains unknown. We aimed to investigate the effect of this combined anesthesia method on POCD/POD incidence after orthopedic surgery, compared with GA.

METHODS

The databases of PubMed, Web of Science, Embase via Ovid, and the Cochrane Central Register of Controlled Trials were searched for all available randomized controlled trials (RCTs). The incidence of POD/POCD was the primary outcome. Continuous and dichotomous outcomes are represented as standardized mean differences [SMD, 95% confidence interval (CI)] and risk ratios [RR, 95%CI], respectively.

RESULTS

Meta-analysis of twelve RCTs with a total of 1488 patients revealed that compared with GA, PNB plus GA decreased the incidence of POCD (RR: 0.58, 95%CI: 0.35 to 0.95, P = 0.03, I2 = 0%), while the incidence of POD had no significant difference (RR: 0.87, 95%CI: 0.54 to 1.40, P = 0.57, I2 = 67%). Compared with GA alone, a significant decrease of intraoperative and postoperative opioid consumption (SMD: -1.54, 95%CI: -2.26 to -0.82, P < 0.0001, I2 = 89%; SMD: -7.00, 95%CI: -9.89 to -4.11, P < 0.00001, I2 = 99%) and postoperative nausea and vomiting incidence (RR: 0.16, 95%CI: 0.06 to 0.44, P = 0.0004, I2 = 0%) was found with PNB plus GA.

CONCLUSIONS

The combined use of PNB and GA decreases the incidence of POCD but not POD following orthopedic surgery.

TRIAL REGISTRATION

The protocol of this study was registered with PROSPERO (Registration Number: CRD42022366454).

Effect of Esketamine on Postoperative Delirium in Patients Undergoing Cardiac Valve Replacement with Cardiopulmonary Bypass: A Randomized Controlled Trial

BACKGROUND

The aim of this study was to investigate the effects of esketamine on the risk of postoperative delirium (POD) in adults undergoing on-pump cardiac valve surgery.

METHODS

In this randomized, triple-blind, controlled trial, 116 adult patients with an American Society of Anesthesiologists (ASA) grade Ⅱ or Ⅲ and a New York Heart Association (NYHA) grade Ⅱ or Ⅲ who underwent cardiac valve surgery with cardiopulmonary bypass were included. Esketamine (0.25 mg/kg) or normal saline was administered intravenously before anesthesia induction. The primary outcome was POD, defined as a positive delirium assessment according to the 3-minute confusion assessment method (CAM) or the confusion assessment method for the intensive care unit (CAM-ICU) on a twice-daily basis for 7 days after surgery. Delirium duration and the delirium subtype were also recorded. The cognitive status of patients was measured according to the Mini-Mental State Examination at baseline, discharge, 30 days postoperatively and 3 months postoperatively.

RESULTS

A total of 112 patients (mean age, 52 years; 53.6% female) were enrolled; 56 were assigned to receive esketamine, and 56 were assigned to receive placebo. POD occurred in 13 (23.2%) patients in the esketamine group and in 25 (44.6%) patients in the placebo group (relative risk [RR], 0.52, 95% confidence interval [CI], 0.28-0.91; P = .018). Thirteen patients (23.2%) in the esketamine group and 24 (42.9%) patients in the placebo group had multiple episodes of delirium (RR, 0.54, 95% CI, 0.28-0.92), and 13 (23.2%) vs 22 (39.3%) patients exhibited the hyperactive subtype.

CONCLUSIONS

A single dose of esketamine (0.25 mg/kg) injected intravenously before anesthesia induction reduced the incidence of delirium in relatively young patients with ASA grade Ⅱ or Ⅲ who underwent on-pump cardiac surgery.

The effect of pre-operative exercise training on post-operative cognitive function: a systematic review

BACKGROUND

With population aging and advances in surgical and anesthetic procedures, the incidence of surgery in patients over the age of 65 years is increasing. One post-operative complication often encountered by older surgical patients is post-operative cognitive dysfunction (POCD). Preoperative exercise training can improve the overall physiological resilience of older surgical patients, yet its impact on post-operative cognition is less well-established.

METHODS

Six databases (Medline (OVID); EMBASE (OVID); EMCARE (OVID); CINAHL (EBSCOHost), the Cochrane Library, and PubMed) were searched for studies reporting the effect of pre-operative physical training on post-operative cognition. The quality of evidence was assessed using the Mixed Methods Assessment Tool.

RESULTS

A total of 3983 studies were initially identified, three of which met the inclusion criteria for this review. Two studies were pilot randomized trials, and one was a prospective randomized trial. Two of the studies were high-quality. Each study used a different type of physical exercise and cognition assessment tool. Across the studies, post-operative cognition (p = 0.005) and attention (p = 0.04) were found to be better in the intervention groups compared to control, with one study reporting no difference between the groups.

CONCLUSION

Preoperative physical training may improve post-operative cognitive function, although more research with a consistent endpoint is required. Future studies should focus on patients at high risk of POCD, such as older adults, and explore the impact of different exercise regimes, including frequency, intensity, time, and type.

Postoperative Delirium and Neurocognitive Disorders: Updates for Providers Caring for Cancer Patients

PURPOSE OF REVIEW

To provide up to date information on postoperative delirium and neurocognitive disorders in surgical cancer patients.

RECENT FINDINGS

Established risk factors such as age, psychosocial factors, comorbidities, frailty and preexisting cognitive decline continue to exhibit associations with perioperative neurocognitive disorders (PND); novel risk factors identified recently include microbiome composition and vitamin D deficiency. Prevention measures include cognitive prehabilitation, perioperative geriatric assessment and multidisciplinary care, dexmedetomidine and multimodal analgesic techniques. Studies investigating ciprofol, remimazolam, esketamine, ramelteon and suvorexant have shown encouraging results. Controversy remains regarding the use of inhalational versus intravenous general anesthesia. Innovative approaches to address PND are a rapidly developing area of research, but more studies are needed to identify effective prevention and management interventions. Despite challenges and controversy in the field, implementation of best practice can reduce the detrimental impact of PND on patients, caregivers, and society at large.

Knowledge mapping of frailty and surgery: a bibliometric and visualized analysis

PURPOSE

Frailty is common in surgical patients and is closely associated with postoperative outcomes.

AIMS

This study employed bibliometric methods to summarize and analyze research related to frailty and surgery, comprehensively analyzing the research structure and providing visualized maps.

METHODS

This study analyzed the volume of publications, countries, institutions, authors, journals, references, and keywords related to perioperative frailty in the Web of Science Core Collection from 1978 to 2024. Visual bibliometric analyses were conducted from multiple perspectives, including collaboration networks, citation analysis, and keyword clustering.

RESULTS

From 1978 to 2024, 21,879 authors from 95 countries and regions published 4,119 papers on perioperative frailty in 973 journals worldwide. The United States has the most publications, while Italy has the highest degree of international collaboration. The University of California System has the highest number of publications. The University of Kansas Medical Center is the institution with the highest centrality. The top nine authors in terms of publication volume are all from the USA. Bowers Christian A. is the most prolific author. The Journal of Vascular Surgery is the journal with the most publications. Current research directions include preoperative risk assessment of frailty, the relationship between frailty and postoperative complications, elderly frailty, and the relationship between frailty and sarcopenia. Research hotspots include risk stratification, postoperative delirium, the elderly, and sarcopenia.

CONCLUSION

This study has identified the research hotspots and trends in perioperative frailty. Our findings will enable researchers to understand this field's knowledge structure better and identify future research directions.

Stressors and coping strategies in older people hospitalised for hip surgery following a fall: a multiple case study

BACKGROUND

More than half of older persons admitted to an emergency department after a fall have a hip fracture and require surgery for a total hip replacement. This procedure has a high risk of postoperative complications and consequences for older persons, their informal caregivers, and the healthcare system. This study aimed to explore the perceptions of older persons, their informal caregivers and health professionals about intra-personal, inter-personal and extra-personal stressors arising from hip surgery following the fall of an older person hospitalised in orthopaedics, as well as the coping strategies used and the results obtained.

METHODS

A qualitative multiple case study. The sample consisted of eight cases. Each case consisted of one older person, their informal caregiver and the professionals involved in their care: a nurse, an orthopaedic surgeon and a physiotherapist. A total of 32 participants were recruited. Data were collected between August 2018 and February 2019 in a public hospital in French-speaking Switzerland. Intra- and inter-case analyses were performed.

RESULTS

Five topics emerged: two concerning stressors for older persons (the physical and psychological consequences of the fall and hospitalisation; the loss of relational and environmental markers and habits); two relating to the coping strategies used to face the stressors (being resilient and involved in their own care; partially meeting the older person's needs); and one regarding the results of the strategies used (reassurance through consideration of some of their needs).

CONCLUSIONS

Older persons hospitalised for hip surgery after a fall are confronted with various intra-, inter- and extra-personal stressors and have to explore, together with their informal caregivers, strategies to cope with the consequences of these stressors. Healthcare professionals should possess efficient intervention strategies to help identify and support older persons who experience various types of stressors during hospitalisation for hip surgery following a fall.

Using Systems Engineering and Implementation Science to Design an Implementation Package for Preoperative Comprehensive Geriatric Assessment Among Older Adults Having Major Abdominal Surgery: Protocol for a 3-Phase Study

BACKGROUND

Older Americans, a growing segment of the population, have an increasing need for surgical services, and they experience a disproportionate burden of postoperative complications compared to their younger counterparts. A preoperative comprehensive geriatric assessment (pCGA) is recommended to reduce risk and improve surgical care delivery for this population, which has been identified as vulnerable. The pCGA optimizes multiple chronic conditions and factors commonly overlooked in routine preoperative planning, including physical function, polypharmacy, nutrition, cognition, mental health, and social and environmental support. The pCGA has been shown to decrease postoperative morbidity, mortality, and length of stay in a variety of surgical specialties. Although national guidelines recommend the use of the pCGA, a paucity of strategic guidance for implementation limits its uptake to a few academic medical centers. By applying implementation science and human factors engineering methods, this study will provide the necessary evidence to optimize the implementation of the pCGA in a variety of health care settings.

OBJECTIVE

The purpose of this paper is to describe the study protocol to design an adaptable, user-centered pCGA implementation package for use among older adults before major abdominal surgery.

METHODS

This protocol uses systems engineering methods to develop, tailor, and pilot-test a user-centered pCGA implementation package, which can be adapted to community-based hospitals in preparation for a multisite implementation trial. The protocol is based upon the National Institutes of Health Stage Model for Behavioral Intervention Development and aligns with the goal to develop behavioral interventions with an eye to real-world implementation. In phase 1, we will use observation and interviews to map the pCGA process and identify system-based barriers and facilitators to its use among older adults undergoing major abdominal surgery. In phase 2, we will apply user-centered design methods, engaging health care providers, patients, and caregivers to co-design a pCGA implementation package. This package will be applicable to a diverse population of older patients undergoing major abdominal surgery at a large academic hospital and an affiliate community site. In phase 3, we will pilot-test and refine the pCGA implementation package in preparation for a future randomized controlled implementation-effectiveness trial. We anticipate that this study will take approximately 60 months (April 2023-March 2028).

RESULTS

This study protocol will generate (1) a detailed process map of the pCGA; (2) an adaptable, user-centered pCGA implementation package ready for feasibility testing in a pilot trial; and (3) preliminary pilot data on the implementation and effectiveness of the package. We anticipate that these data will serve as the basis for future multisite hybrid implementation-effectiveness clinical trials of the pCGA in older adults undergoing major abdominal surgery.

CONCLUSIONS

The expected results of this study will contribute to improving perioperative care processes for older adults before major abdominal surgery.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/59428.

Postoperative Delirium and Neurocognitive Disorders: A Comprehensive Review of Pathophysiology, Risk Factors, and Management Strategies

Postoperative delirium (POD) and neurocognitive disorders (NCDs) are common and serious complications that can occur after surgery, particularly in older adults and those with preexisting cognitive impairments. These conditions are associated with significant morbidity, increased healthcare costs, and reduced quality of life. Understanding the underlying mechanisms, risk factors, and effective management strategies for POD and NCDs is critical for improving patient outcomes and reducing the burden on healthcare systems. This comprehensive review aims to synthesize current knowledge on the pathophysiology, risk factors, and management strategies for POD and NCDs. It explores the neurobiological and molecular mechanisms contributing to these conditions, identifies the patient-related, surgical, and environmental factors that increase risk, and evaluates pharmacological and non-pharmacological approaches to prevention and treatment. A thorough literature review was conducted using recent studies, clinical guidelines, and expert consensus to provide a detailed overview of the pathophysiology, risk factors, clinical presentation, prevention, and management of POD and NCDs. The pathophysiology of POD and NCDs involves complex interactions between neuroinflammatory processes, neurotransmitter imbalances, and brain network disruptions. Risk factors include advanced age, preexisting cognitive impairment, type and duration of surgery, and perioperative complications. Management strategies emphasize a multidisciplinary approach, incorporating preoperative optimization, careful intraoperative management, and postoperative interventions. Pharmacological treatments, such as antipsychotics, and non-pharmacological approaches, including environmental modifications and cognitive rehabilitation, play crucial roles in management. Postoperative delirium and NCDs are multifactorial conditions with significant impacts on surgical outcomes. Effective management requires a comprehensive understanding of their pathophysiology and risk factors and the implementation of targeted prevention and treatment strategies. Future research should focus on personalized approaches to prevention and treatment, further elucidation of mechanisms, and developing predictive models to enhance care for patients at risk of these neurocognitive complications.

Personalised blood pressure management during major noncardiac surgery and postoperative neurocognitive disorders: a randomised trial

Background

It remains unknown whether there is a causal relationship between intraoperative hypotension and postoperative neurocognitive disorders. We tested the hypothesis that personalised-compared to routine-intraoperative blood pressure management reduces the incidence of postoperative neurocognitive disorders in patients having major noncardiac surgery.

Methods

In this single-centre trial, 328 elective major noncardiac surgery patients were randomly allocated to receive personalised blood pressure management (i.e. maintaining intraoperative mean arterial pressure [MAP] above preoperative baseline MAP from automated 24-h blood pressure monitoring) or routine blood pressure management (i.e. maintaining MAP above 65 mm Hg). The primary outcome was the incidence of neurocognitive disorders (composite of delayed neurocognitive recovery and delirium) between postoperative days 3 and 7.

Results

The primary outcome, neurocognitive disorders, occurred in 18 of 147 patients (12%) assigned to personalised and 21 of 148 patients (14%) assigned to routine blood pressure management (odds ratio [OR]=0.84, 95% confidence interval [CI]: 0.40-1.75, P=0.622). Delayed neurocognitive recovery occurred in 17 of 146 patients (12%) assigned to personalised and 17 of 145 patients (12%) assigned to routine blood pressure management (OR=0.99, 95% CI: 0.45-2.17, P=0.983). Delirium occurred in 2 of 157 patients (1%) assigned to personalised and 4 of 158 patients (3%) assigned to routine blood pressure management (OR=0.50, 95% CI: 0.04-3.53, P=0.684).

Conclusions

Personalised intraoperative blood pressure management maintaining preoperative baseline MAP neither reduced the incidence of the composite primary outcome neurocognitive disorders between postoperative days 3 and 7 nor the incidences of the components of the composite primary outcome-delayed neurocognitive recovery and delirium-compared to routine blood pressure management in patients having major noncardiac surgery.

Clinical trial registration

ClinicalTrials.gov (NCT03442907).

Emerging Trends and Hot Topics of Non-Invasive Electroencephalography Research in the Elderly: A Bibliometric Analysis from 2014 to 2023

Background

Electroencephalography (EEG) has been rapidly developed and is widely used in both clinical and scientific fields. Original studies on non-invasive EEG in the elderly have been of great importance owing to the global aging trend. The present study aimed to provide a bibliometric overview on current status and trends in this research field.

Methods

We searched the Web of Science Core Collection for articles published during 2014 and 2023. Synonyms for EEG and the elderly were combined as a retrieval strategy. Invasive EEG and secondary studies were excluded. Online filters and manual reviews were applied to select eligible articles. Basic bibliometric parameters were analyzed and visualized using VOSviewer and Excel software.

Results

A total of 1656 publications were filtered, and 655 of which were finally included. In general, publication counts have steadily increased over the last 10 years. A sharp rise in publications occurred in 2021, and then remained at a high level. Authors and institutions from high-income countries/regions such as the United States of America (USA), China, and Germany were more productive and made significant contributions. Journals specialized in neuroscience, such as Frontiers in Aging Neuroscience, Neurobiology of Aging, and Clinical Neurophysiology, were popular among authors. Articles on aging, Alzheimer's disease (AD), mild cognitive impairment (MCI), dementia, memory, event-related potentials, attention, and the brain were more likely to use EEG. The newer topics included anesthesia, postoperative delirium (POD), confusion assessment method, connectivity, validation, and power.

Conclusion

This bibliometric study provides fundamental knowledge on the current status and hot spots of the original studies on EEG in elderly, which is beneficial to researchers in paving future investigations of neuroscience and neural diseases.

Incidence and related risk factors for postoperative delirium following revision total knee arthroplasty: a retrospective nationwide inpatient sample database study

BACKGROUND

Postoperative delirium (POD) is a common surgical complication. However, the incidence and risk factors associated with postoperative delirium after revision total knee arthroplasty (rTKA) have not been comprehensively explored through extensive national databases.

METHODS

Utilizing the National Inpatient Sample (NIS), the largest comprehensive U.S. hospital healthcare database, we undertook a retrospective investigation involving 127,400 patients who underwent rTKA between 2010 and 2019. We assessed various aspects, including patient demographics, hospital characteristics, pre-existing medical conditions, and perioperative complications.

RESULTS

The overall incidence of postoperative delirium (POD) in patients undergoing rTKA between 2010 and 2019 was 0.97%. The highest incidence rate of 1.31% was recorded in 2013. Notably, this patient cohort demonstrated advanced age, increased burden of co-morbidities, prolonged hospital stays, increased hospitalization costs, and elevated in-hospital mortality rates (P < 0.001). Moreover, non-elective admissions, non-private insurance payments, and a preference for teaching hospitals were commonly observed among these patients. During their hospitalization, individuals who developed delirium subsequent to rTKA were more prone to experiencing certain perioperative complications. These complications encompassed medical issues like acute myocardial infarction, continuous invasive mechanical ventilation, postoperative shock, sepsis, stroke and other medical problems. Additionally, surgical complications including hemorrhage / seroma / hematoma, irrigation and debridement, prosthetic joint infection, periprosthetic fracture, and wound dehiscence / nonunion were noted. Several risk factors were found to be linked with the development of POD. These included advanced age (≥ 75 years), alcohol abuse, coagulation disorders, congestive heart failure, depression, fluid and electrolyte imbalances, and more. Conversely, female sex, having private insurance, and undergoing elective hospitalization emerged as protective factors against POD.

CONCLUSION

Our findings suggest that the general prevalence of POD in rTKA is relatively low according to NIS. There was a significant connection between the POD of rTKA and advanced age, prolonged length of stay (LOS), more in-patients' costs, higher in-hospital mortality rate, increased comorbidities, postoperative medical complications and postoperative surgical complications. This study helps to understand the risk factors associated with POD to improve poor outcomes.

Exploring Cognitive Changes in High-Risk Cardiac Patients Receiving Dexmedetomidine and Evaluating the Correlation between Different Cognitive Tools: A Cohort Study

Background

Mini-mental State Examination (MMSE) is widely accepted clinically for postoperative cognitive dysfunction (POCD) assessment. This study aims to investigate the post-operative cognitive changes among high-risk cardiothoracic patients and establish a standardised approach to post-surgery cognitive assessment.

Methods

This is a prospective cohort study, where cognitive assessments were done 1-day before surgery, at discharge, and during 6 weeks of follow-up. Sample size calculation, accounting for an estimated 20% dropout rate, determined a minimum of 170 subjects were required for the study. Reduction of MMSE score of more than 2.5 was considered as having POCD. Score differences between groups were analysed using T-test and analysis of variance (ANOVA), while consistency between tools was analysed using correlation and regression.

Results

A total of 188 patients completed the study, with a POCD prevalence of 20.2% and 6.9% at discharge and at the 6 week follow up, respectively. All cognitive tools show a significant difference between preoperative and postoperative scores. All tests show a significant moderate correlation with MMSE.

Conclusions

In conclusion, it is imperative to employ a battery of cognitive assessments to evaluate cognitive changes comprehensively.

Preoperative ketamine administration for prevention of postoperative neurocognitive disorders after major orthopedic surgery in elderly patients: A multicenter randomized blinded placebo-controlled trial

BACKGROUND

Preventive anesthetic impact on the high rates of postoperative neurocognitive disorders in elderly patients is debated. The Prevention of postOperative Cognitive dysfunction by Ketamine (POCK) study aimed to assess the effect of ketamine on this condition.

METHODS

This is a multicenter, randomized, double-blind, interventional study. Patients ≥60 years undergoing major orthopedic surgery were randomly assigned in a 1:1 ratio to receive preoperative ketamine 0.5 mg/kg as an intravenous bolus (n = 152) or placebo (n = 149) in random blocks stratified according to the study site, preoperative cognitive status and age. The primary outcome was the proportion of objective delayed neurocognitive recovery (dNR) defined as a decline of one or more neuropsychological assessment standard deviations on postoperative day 7. Secondary outcomes included a three-month incidence of objective postoperative neurocognitive disorder (POND), as well as delirium, anxiety, and symptoms of depression seven days and three months after surgery.

RESULTS

Among 301 patients included, 292 (97%) completed the trial. Objective dNR occurred in 50 (38.8%) patients in the ketamine group and 54 (40.9%) patients in the placebo group (OR [95% CI] 0.92 [0.56; 1.51], p = 0.73) on postoperative day 7. Incidence of objective POND three months after surgery did not differ significantly between the two groups nor did incidence of delirium, anxiety, apathy, and fatigue. Symptoms of depression were less frequent in the ketamine group three months after surgery (OR [95% CI] 0.34 [0.13-0.86]).

CONCLUSIONS

A single preoperative bolus of intravenous ketamine does not prevent the occurrence of dNR or POND in elderly patients scheduled for major orthopedic surgery. (Clinicaltrials.gov NCT02892916).

Summary of the Clinical Evidence for Non-Pharmacological Management of Postoperative Delirium in Adults: An Evidence Synthesis

Objective

To retrieve, evaluate, and summarise the clinical evidence for non-pharmacological interventions in adult postoperative delirium (POD), encompassing the preoperative, intraoperative, and postoperative phases.

Methods

The methods included conducting searches on UpToDate Clinical Consultants, the Scottish Intercollegiate Guidelines Network, the National Institute for Health and Care Excellence, the Registered Nurses' Association of Ontario, BMJ Best Practice, the Cochrane Library, Web of Science, PubMed, China National Knowledge Infrastructure, Wanfang, VIP, and the Chinese Biomedical Literature Service System. Clinical practice guidelines, clinical decision-making, evidence summaries, evidence synthesis, expert consensus, systematic reviews, and meta-analyses on non-pharmacological interventions for adult POD were examined, and the search period spanned between the establishment of each database and 30 October 2023.

Results

A total of 17 documents were included, comprising three guidelines, one expert consensus, one clinical decision-making article, four evidence summaries, three systematic reviews, and five meta-analyses. These documents primarily focused on the following three aspects: preoperative, intraoperative, and postoperative care. In total, 30 "best evidence" instances were compiled.

Conclusion

Considering the complexity and potential harm of adult POD, an accurate and timely evaluation of high-risk factors, alongside effective medical nursing strategies, is vital in its prevention and treatment. Non-pharmacological interventions remain the preferred choice for preventing and treating POD. Medical institutions should establish standardised processes for non-pharmacological intervention in adult POD, based on evidence-based medicine, to enhance the level of clinical care in this field.

Predictiveness of preoperative laboratory values for postoperative delirium

Background

Postoperative delirium (POD) is a common postoperative complication, especially in patients over 60 years, with an incidence ranging from 15% to 50%. In most cases, POD manifests in the first 5 days after surgery. Multiple contributing risk factors for POD have been detected. Besides the predisposing factors such as higher age, cognitive impairment, high blood pressure, atrial fibrillation, and past stroke, pathophysiological mechanisms like neuroinflammation are also considered as contributing factors.

Methods

In a subanalysis of the "PRe- Operative  Prediction of postoperative  DElirium by appropriate  SCreening" (PROPDESC) study, the preoperative laboratory values of sodium, potassium, total protein, hemoglobin concentration (Hgb), and white blood cells as well as the biomarkers creatinine, HbA1c, NT-pro-BNP, high sensitive Troponin T (hsTnT), and C-reactive protein (CRP) were assessed to investigate a possible relationship to the occurrence of POD.

Results

After correction for age, physical status classification, surgery risk after Johns Hopkins, and operative discipline (cardiac surgery vs. noncardiac surgery), male patients with a Hgb <13 g/dL had significantly higher odds for POD (p = 0.025). Furthermore, patients with CRP ≥ 10 mg/L, HbA1c value ≥ 8.5% as well as patients with hypernatraemia (>145 mmol/L) presented significantly higher odds to develop POD (p = 0.011, p < 0.001, and p = 0.021, respectively). A raised (>14-52 ng/L) or high (>52 ng/L) hsTnT value was also associated with a significantly higher chance for POD compared to the patient group with hsTnT <14 ng/L (p < 0.001 and p = 0.016, respectively).

Conclusions

Preoperative Hgb, CRP, HbA1c, sodium, and hsTnT could be used to complement and refine the preoperative screening for patients at risk for POD. Further studies should track these correlations to investigate the potential of targeted POD protection and enabling hospital staff to initiate POD-preventing measures in time.

Postoperative cognitive dysfunction: a concept analysis

BACKGROUND

Post-operative cognitive dysfunction (POCD) is a concern for clinicians that often presents post-surgery where generalized anesthesia has been used. Its prevalence ranges from 36.6% in young adults to 42.4% in older individuals. Conceptual clarity for POCD is lacking in the currently body literature. Our two-fold purpose of this concept analysis was to (1) critically appraise the various definitions, while also providing the best definition, of POCD and (2) narratively synthesize the attributes, surrogate or related terms, antecedents (risk factors), and consequences of the concept.

METHOD

The reporting of our review was guided by the PRISMA statement and the 6-step evolutionary approach to concept analysis developed by Rodgers. Three databases, including Medline, CINAHL, and Web of Science, were searched to retrieve relevant literature on the concept of POCD. Two independent reviewers conducted abstract and full-text screening, data extraction, and appraisal. The review process yielded a final set of 86 eligible articles.

RESULT

POCD was defined with varying severities ranging from subtle-to-extensive cognitive changes (1) affecting single or multiple cognitive domains that manifest following major surgery (2), is transient and reversible, and (3) may last for several weeks to years. The consequences of POCD may include impaired quality of life, resulting from withdrawal from the labor force, increased patients' dependencies, cognitive decline, an elevated risk of dementia, rising healthcare costs, and eventual mortality.

CONCLUSION

This review resulted in a refined definition and comprehensive analysis of POCD that can be useful to both researchers and clinicians. Future research is needed to refine the operational definitions of POCD so that they better represent the defining attributes of the concept.

Efficacy and safety of intranasal insulin on postoperative cognitive dysfunction in elderly patients after laparoscopic radical resection of colorectal cancer: a double-blind pilot study

Objective

To evaluate the efficacy and safety of intranasal insulin on postoperative cognitive dysfunction (POCD) in elderly patients after laparoscopic radical resection of colorectal cancer.

Methods

Older patients scheduled for laparoscopic radical resection of colorectal cancer at Beijing Luhe Hospital, Capital Medical University, between August 2023 and November 2023, were enrolled in this double-blind pilot study. Patients were randomized to the control and insulin groups at a 1:1 ratio. The primary outcome was the rate of POCD at postoperative 7 days.

Results

A total of 61 patients (30 in the insulin group) were analyzed. The insulin group had a significantly lower POCD rate compared with the control group at postoperative day 7 [4(13.3%) vs. 12 (38.7%), p = 0.024]. The serum levels of IL-6, TNF-α and S100β at T2-5 in the insulin group were significantly lower than those of the control group (IL-6: mean difference at T2, -4.14, p = 0.036; T3, -3.84, p = 0.039; T4, -3.37, p = 0.013; T5, -2.57, p = 0.042; TNF-α: mean difference at T2, -3.19, p = 0.002; T3, -2.35, p = 0.028; T4, -2.30, p = 0.019; T5, -1.96, p = 0.0181; S100β: mean difference at T2, -8.30, p = 0.019; T3, -23.95, p = 0.020; T4, -20.01, p = 0.023; T5, -17.67, p = 0.010). No insulin allergic reactions, nasal irritation, or hypoglycemic reactions were observed in either of the groups.

Conclusion

Intranasal insulin may decrease the risk of POCD and inhibit the elevated serum IL-6, TNF-α, and S100β levels in elderly patients after laparoscopic radical resection of colorectal cancer, which proves that intranasal insulin may be a promising therapeutic option for POCD.

Clinical trial registration

Identifier, ChiCTR2300074423.

Global research and scientific publications on PND between 1969 and 2022: A bibliometric analysis

Objectives

We hope to offer a comprehensive understanding of the advancements and patterns in research on PND. Methods: We performed a thorough search on the Web of Science Core Collection to locate relevant studies published from 1969 to 2022 and utilized four distinct tools, namely VOSviewer (J Data Inf Sci, 2017, 2, 1; J Am Soc Inf Sci, 1973, 24, 265; Amer Doc, 1963, 14, 10 and Scientometrics, 2010, 82, 581), CiteSpace (Scientometrics, 2010, 84, 523), Scimago Graphica, and R-bibliometrix which allowed us to examine various aspects. Results: We included a total of 6787 articles and reviews for analysis which described PND research, the sources, and the subfields; highlighted the significant developments in this field; identified three main directions in PND.Conclusion: This study highlights the rapid growth of research on PND in recent years and provided an overview of previous studies in the field of PND, thereby establishing the overall landscape of PND research and identifying potential avenues for future investigations.

Methods

We performed a thorough search on the Web of Science Core Collection to locate relevant studies published from 1969 to 2022. To perform bibliometric analysis and network visualization, we utilized four distinct tools, namely VOSviewer (J Data Inf Sci, 2017, 2, 1; J Am Soc Inf Sci, 1973, 24, 265; Amer Doc, 1963, 14, 10 and Scientometrics, 2010, 82, 581), CiteSpace (Scientometrics, 2010, 84, 523), Scimago Graphica, and R-bibliometrix. These tools allowed us to examine various aspects, including the yearly publication output, the contribution of different countries or regions, the involvement of active journals, co-citation analysis, publication status, keywords, and terms, as well as scientific categories. We hope to offer a comprehensive understanding of the advancements and patterns in research on PND. The insights gained from this study can assist researchers and clinicians in enhancing the management and implementation of their work in this field.

Results

In this study, we included a total of 6787 articles and reviews for analysis. First, publication trends and contribution by country analysis described PND research. Second, a historical analysis described PND research, the sources, and the subfields. Third, an analysis of keywords highlighted the significant developments in this field. Fourth, an analysis of research themes identified three main directions in PND.

Conclusion

In summary, the research volume exhibits exponential growth over time. Furthermore, the majority of contributions originate from Western countries and China. The interdisciplinary nature of the field is evident, with its roots in biology and medicine and further branching into psychology and social sciences. POCD, delirium-predominant associated clinical management were major research themes about PND.

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

OBJECTIVE

Perioperative Neurocognitive Disorders (PND) is a common neurological complication after radical colorectal cancer surgery, which increases adverse outcomes. So, our objective is to explore the influence of dexmedetomidine added to ropivacaine for transversus abdominis plane block (TAPB) on perioperative neurocognitive disorders, and to provide a new way to reduce the incidence of PND.

METHODS

One hundred and eighty patients submitted to radical laparoscopic colorectal cancer surgery were randomly divided into Control group and Dex group. Ultrasound guided TAPB was performed after anesthesia induction: 0.5% ropivacaine 20 ml was injected into each transversus abdominis plane in Control group, 0.5% ropivacaine + 1 μg/kg dexmedetomidine (amounting to 20 ml) in Dex group. We observed the incidence of PND within 30 days after surgery.

RESULTS

One hundred and sixty-nine cases were finally analyzed, including 84 cases in Control group and 85 cases in Dex group. Compared with Control group, there was no significant difference in terms of the incidence of PND on the 3rd day and the 7th day (P > 0.05), but the incidence significantly decreased at the 6th hour, at the 24th hour and on the 30th day after surgery (P < 0.05) in Dex group.

CONCLUSION

Dexmedetomidine added to ropivacaine for TAPB can reduce the incidence of PND in the first 24 h after surgery and on the 30th postoperative day, which may be related to reduce the consumption of general anesthetics and provide satisfactory postoperative analgesia.

TRIAL REGISTRATION

29 /05/ 2021, ChiCTR2100046876.

Characteristics of the top 100 cited electroencephalography articles on aging: a bibliometric analysis

Electroencephalography (EEG) is a widely used tool in neuroscience. To explore the features of the top 100 cited articles related to EEG and aging over the past decade, we conducted a bibliometric analysis using Web of Science Core Collection (WoSCC) data as of January 21, 2024. The selected top 100 cited papers were analyzed using VOSviewer and Excel. We examined the distribution of publication years, authors, institutions, countries/regions, and journals. Hotspots were identified through keyword analysis. The analyzed articles were published between 2014 and 2021, with the majority being published before 2020 (n=91). Citation counts in WoSCC ranged from 24 to 250, with a median of 40 and a mean of 53. A total of 818 authors from 283 institutions in 35 countries/territories contributed to these top papers. The United States of America (USA) (n=37), Germany (n=14), and Canada (n=11) ranked in the top three in terms of total publications or citations. The predominant journals were in the fields of Neuroscience (n=58), Geriatrics & Gerontology (n=22), Clinical Neurology (n=13), and Anesthesiology (n=9), which published most of the high-quality articles. Key themes included EEG, aging, Alzheimer's disease, mild cognitive impairment, functional connectivity, and alpha oscillations. Emerging topics included sleep, machine learning, delirium, postoperative cognitive function, virtual reality, monitoring, resting state, coherence, and transcranial direct current stimulation. In conclusion, this study provides a comprehensive overview of the trends in scientific literature on EEG in aging over the past decade. Authors and institutions from North America, Europe, and East Asia led in contributions. Journals focusing on neuroscience, geriatrics, and anesthesiology published the majority of articles. Degenerative neurological diseases and cognitive impairment were prominent topics, suggesting future studies should explore EEG's diagnostic utility for these disorders.

Lower alpha frequency of intraoperative frontal EEG is associated with postoperative delirium: A secondary propensity-matched analysis

BACKGROUND

Postoperative delirium (POD) is a serious complication of surgery, especially in the elderly patient population. It has been proposed that decreasing the amount of anesthetics by titrating to an EEG index will lower POD rate, but clear evidence is missing. A strong age-dependent negative correlation has been reported between the peak oscillatory frequency of alpha waves and end-tidal anesthetic concentration, with older patients generating slower alpha frequencies. We hypothesized, that slower alpha oscillations are associated with a higher rate of POD.

METHOD

Retrospective analysis of patients` data from a prospective observational study in cardiac surgical patients approved by the Bernese Ethics committee. Frontal EEG was recorded during Isoflurane effect-site concentrations of 0.7 to 0.8 and peak alpha frequency was measured at highest power between 6 and 17 Hz. Delirium was assessed by chart review. Demographic and clinical characteristics were compared between POD and non-POD groups. Selection bias was addressed using nearest neighbor propensity score matching (PSM) for best balance. This incorporated 18 variables, whereas patients with missing variable information or without an alpha oscillation were excluded.

RESULT

Of the 1072 patients in the original study, 828 were included, 73 with POD, 755 without. PSM allowed 328 patients into the final analysis, 67 with, 261 without POD. Before PSM, 8 variables were significantly different between POD and non-POD groups, none thereafter. Mean peak alpha frequency was significantly lower in the POD in contrast to non-POD group before and after matching (7.9 vs 8.9 Hz, 7.9 vs 8.8 Hz respectively, SD 1.3, p < 0.001).

CONCLUSION

Intraoperative slower frontal peak alpha frequency is independently associated with POD after cardiac surgery and may be a simple intraoperative neurophysiological marker of a vulnerable brain for POD. Further studies are needed to investigate if there is a causal link between alpha frequency and POD.

Dexmedetomidine alleviates sevoflurane-induced neuroinflammation and neurocognitive disorders by suppressing the P2X4R/NLRP3 pathway in aged mice

PURPOSE

Microglia-mediated inflammation is associated with perioperative neurocognitive disorders (PNDs) caused by sevoflurane. Dexmedetomidine has been reported to protect against sevoflurane-induced cognitive impairment. In this study, we investigated the effects and underlying mechanisms of dexmedetomidine on sevoflurane-induced microglial neuroinflammation and PNDs.

METHODS

Wild-type and purinergic ionotropic 4 receptor (P2X4R) overexpressing C57/BL6 mice were intraperitoneally injected with 20 μg/kg dexmedetomidine or an equal volume of normal saline 2 h prior to sevoflurane exposure. The Morris water maze (MWM) test was performed to assess cognitive function. Immunofluorescence staining was employed to detect microglial activation. The expression levels of proinflammatory cytokines were measured by real-time quantitative PCR (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA). The protein levels of P2X4R and NOD-like receptor protein 3 (NLRP3) were detected by Western Blotting.

RESULTS

Sevoflurane increased the number of microglia, upregulated the levels of proinflammatory cytokines, elevated the protein levels of P2X4R and NLRP3 in the hippocampus and induced cognitive decline, while pretreatment with dexmedetomidine downregulated the protein levels of P2X4R and NLRP3, alleviated sevoflurane-induced microglial neuroinflammation and improved cognitive dysfunction. Moreover, overexpression of P2X4R weakened the neuroprotective effect of dexmedetomidine.

CONCLUSIONS

Dexmedetomidine protected against sevoflurane-induced neuroinflammation and neurocognitive disorders by suppressing the P2X4R/NLRP3 pathway.

Triglyceride-glucose index predicts postoperative delirium in elderly patients with type 2 diabetes mellitus: a retrospective cohort study

BACKGROUND

Postoperative delirium (POD) is more prevalent among elderly patients with type 2 diabetes mellitus (T2DM). Insulin resistance (IR) can be assessed using the triglyceride-glucose (TyG) index, a novel biomarker. This study aims to investigate the predictive potential of the TyG index for POD in elderly patients with T2DM.

MATERIALS AND METHODS

Elderly patients (≥ 65) with T2DM who underwent non-neurosurgery and non-cardiac surgery were enrolled. Univariate and multivariate logistic regression analyses were conducted to assess the association between the TyG index and POD. Additionally, subgroup analyses were performed to compare the sex-specific differences in the predictive ability of the TyG index for POD.

RESULTS

A total of 4566 patients were included in this retrospective cohort. The receiver operating characteristic (ROC) curve analysis determined the optimal cut-off value for the TyG index to be 8.678. In the univariate model, a TyG index > 8.678 exhibited an odds ratio (OR) of 1.668 (95% CI: 1.210-2.324, P = 0.002) for predicting POD. In the multivariate regression models, the ORs were 1.590 (95% CI: 1.133-2.252, P < 0.008), 1.661 (95% CI: 1.199-2.325, P < 0.003), and 1.603 (95% CI: 1.137-2.283, P = 0.008) for different models. Subgroup analyses demonstrated that the predictive ability of the TyG index was more pronounced in females compared to males.

CONCLUSION

The TyG index shows promise as a novel biomarker for predicting the occurrence of POD in elderly surgical patients with T2DM.

Intraoperative EEG-based monitors: are we looking under the lamppost?

PURPOSE OF REVIEW

While electroencephalogram (EEG)-based depth of anesthesia monitors have been in use clinically for decades, there is still a major debate concerning their efficacy for detecting awareness under anesthesia (AUA). Further utilization of these monitors has also been discussed vividly, for example, reduction of postoperative delirium (POD).It seems that with regard to reducing AUA and POD, these monitors might be applicable, under specific anesthetic protocols. But in other settings, such monitoring might be less contributive and may have a 'built-it glass ceiling'.Recent advances in other venues of electrophysiological monitoring might have a strong theoretical rationale, and early supporting results, to offer a breakthrough out of this metaphorical glass ceiling. The purpose of this review is to present this possibility.

RECENT FINDINGS

Following previous findings, it might be concluded that for some anesthesia protocols, the prevailing depth of anesthesia monitors may prevent incidences of AUA and POD. However, in other settings, which may involve other anesthesia protocols, or specifically for POD - other perioperative causes, they may not. Attention-related processes measured by easy-to-use real-time electrophysiological markers are becoming feasible, also under anesthesia, and might be applicable for more comprehensive prevention of AUA, POD and possibly other perioperative complications.

SUMMARY

Attention-related monitoring might have a strong theoretical basis for the prevention of AUA, POD, and potentially other distressing postoperative outcomes, such as stroke and postoperative neurocognitive disorder. There seems to be already some initial supporting evidence in this regard.

Knowledge, attitudes, and practice toward postoperative cognitive dysfunction among anesthesiologists in China: a cross-sectional study

BACKGROUND

To investigate the knowledge, attitudes, and practice (KAP) toward postoperative cognitive dysfunction (POCD) among anesthesiologists in China.

METHODS

This cross-sectional study was conducted nationwide among Chinese anesthesiologists between December 2022 and January 2023. The demographic information and KAP scores of the respondents were collected using a web-based questionnaire. The mean KAP dimension scores ≥ 60% were considered good.

RESULTS

This study enrolled 1032 anesthesiologists (51.2% male). The mean total scores of knowledge, positive attitude, and positive practice were 9.3 ± 1.2 (max 12), 34.8 ± 3.3 (max 40), and 30.6 ± 6.7 (max 40), respectively. The knowledge items with correctness scores < 60% were "the anesthetic drugs that tend to cause POCD" (23.3%) and "Treatment of POCD" (40.3%). Multivariable analysis showed that ≥ 40 years old, master's degree or above, intermediate professional title (i.e., attending physician), senior professional title (i.e., chief physician), and working in tertiary hospitals were independently associated with adequate knowledge. Multivariable analysis showed that the attitude scores, middle professional title, and ≥ 16 years of experience were independently associated with good practice.

CONCLUSIONS

These results suggest that Chinese anesthesiologists have good knowledge, favorable attitudes, and good practice toward POCD. Still, some points remain to be improved (e.g., the drugs causing POCD and managing POCD) and should be emphasized in training and continuing education.

TRIAL REGISTRATION

ChiCTR2200066749.

Association Between Anesthetics and Postoperative Delirium in Elderly Patients Undergoing Spine Surgery: Propofol Versus Sevoflurane

STUDY DESIGNS

Retrospective Observational StudyObjectives: To compare the incidence of POD after propofol- and sevoflurane-based anesthesia in elderly patients undergoing spine surgery.

METHODS

In this study, the medical records of elderly patients ≥ 65 years of age who underwent spine surgery under total intravenous anesthesia with propofol or inhalational anesthesia with sevoflurane were reviewed. The primary outcome was the incidence of POD after propofol- and sevoflurane-based anesthesia. Secondary outcomes included postoperative 30-day complications, length of postoperative hospital stay, associations of patient characteristics, and surgery- and anesthesia-related data with the development of POD, and associations of anesthetics with clinical outcomes such as postoperative 30-day complications, and length of postoperative hospital stay.

RESULTS

Of the 281 patients, POD occurred in 29 patients (10.3%). POD occurred more frequently in the sevoflurane group than in the propofol group (15.7% vs. 5.0%, respectively; P=.003). The multivariable logistic regression analysis showed that sevoflurane-based anesthesia was associated with an increased risk of POD compared with propofol-based anesthesia (odds ratio [OR], 4.120; 95% confidence interval [CI], 1.549-10.954; P = .005), whereas anesthetics were not associated with postoperative 30-day complications and the length of postoperative hospital stay. Older age (OR, 1.242 CI, 1.130-1.366; P < .001) and higher mean pain score at postoperative day 1 (OR, 1.338 CI, 1.056-1.696; P = .016) were also associated with an increased risk of POD.

CONCLUSIONS

Propofol-based anesthesia was associated with a lower incidence of POD than sevoflurane-based anesthesia in elderly patients after spine surgery.

Unveiling the role of astrocytes in postoperative cognitive dysfunction

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

Postoperative cognitive worsening in seniors with an age above life expectancy: a prospective longitudinal study

BACKGROUND

The growing number of elderly patients in hospitals is a challenge for healthcare systems. The main objective is to measure the postoperative change in the cognitive status at hospital discharge and one year after discharge in elderly patients undergoing planned or deferrable surgery.

METHODS

We planned a prospective longitudinal study, single-center study: secondary care level hospital, enrolment from September 2018 to May 2019. We enroll elderly patients, aged above life expectancy in Italy, who underwent planned or deferrable surgery (men over 80.5 years old, women over 85.0 years old). In six months, we enrolled 76 eligible patients. We collected the scores of the clinical impairment scales Charlson Index, Barthel Index, and Six-Item Cognitive Impairment Test (6CIT). The primary endpoint was the postoperative worsening of the cognitive status at one-year follow-up. Secondary endpoints aimed to describe postoperative disabilities and complications, to investigate possible risk factors for cognitive worsening, and to measure the role of anesthesia in cognitive changes.

RESULTS

We recorded an increased rate of pathological 6CIT values during the hospitalization period, rising from 39.47% to 55.26% (McNemar test, P=0.007), and this rate was still increased at 55.56% (P=0.021) one year after discharge. Anesthesia did not show any significant harmful effect on cognitive status. The preoperative hemoglobin value seems to be a risk factor for cognitive status and one-year mortality.

CONCLUSIONS

Elderly patients had a significantly worse 6CIT value after planned surgery, which may derive in part from age and in part from hospitalization. It is difficult to determine if general anesthesia alone has no harmful effects on cognitive performance in patients at discharge and one year later. Further data are necessary.

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

STUDY OBJECTIVE

This meta-analysis aimed to assess whether continuous intravenous administration of DEX during surgery can be part of the measures to prevent the onset of postoperative delirium and postoperative cognitive dysfunction in elderly individuals following regional anesthesia.

METHODS

We searched the databases of PubMed, Embase, the Cochrane Library and China National Knowledge Infrastructure (by June 1, 2023) for all available randomized controlled trials assessing whether intravenous application of dexmedetomidine can help with postoperative delirium and postoperative cognitive dysfunction in the elderly with regional anesthesia. Subsequently, we carried out statistical analysis and graphing using Review Manager software (RevMan version 5.4.1) and STATA software (Version 12.0).

MAIN RESULTS

Within the scope of this meta-analysis, a total of 18 randomized controlled trials were included. Among them, 10 trials aimed to assess the incidence of postoperative delirium as the primary outcome, while the primary focus of the other 8 trials was on the incidence of postoperative cognitive dysfunction. The collective evidence from these 10 studies consistently supports a positive relationship between the intravenous administration of dexmedetomidine and a decreased risk of postoperative delirium (RR: 0.48; 95%CI: 0.37 to 0.63, p < 0.00001, I2 = 0%). The 8 literature articles and experiments evaluating postoperative cognitive dysfunction showed that continuous intravenous infusion of dexmedetomidine during the entire surgical procedure exhibited a positive preventive effect on cognitive dysfunction among the elderly population with no obvious heterogeneity (RR: 0.35; 95%CI: 0.25 to 0.49,p < 0.00001, I2 = 0%).

CONCLUSION

Administering dexmedetomidine intravenously during surgery can potentially play a significant role in preventing postoperative delirium and postoperative cognitive dysfunction in patients older than 60 years with regional anesthesia according to this meta-analysis.

Role of Intraoperative Neuromonitoring to Predict Postoperative Delirium in Cardiovascular Surgery

OBJECTIVE

Postoperative delirium (POD) can occur in up to 50% of older patients undergoing cardiovascular surgery, resulting in hospitalization and significant morbidity and mortality. This study aimed to determine whether intraoperative neurophysiologic monitoring (IONM) modalities can be used to predict delirium in patients undergoing cardiovascular surgery.

DESIGN

Adult patients undergoing cardiovascular surgery with IONM between 2019 and 2021 were reviewed retrospectively. Delirium was assessed multiple times using the Intensive Care Delirium Screening Checklist (ICDSC). Patients with an ICDSC score ≥4 were considered to have POD. Significant IONM changes were evaluated based on a visual review of electroencephalography (EEG) and somatosensory evoked potentials data and documentation of significant changes during surgery.

SETTING

University of Pittsburgh Medical Center hospitals.

PARTICIPANTS

Patients 18 years old and older undergoing cardiovascular surgery with IONM monitoring.

MEASUREMENTS AND MAIN RESULTS

Of the 578 patients undergoing cardiovascular surgery with IONM, 126 had POD (21.8%). Significant IONM changes were noted in 134 patients, of whom 49 patients had delirium (36.6%). In contrast, 444 patients had no IONM changes during surgery, of whom 77 (17.3%) patients had POD. Upon multivariate analysis, IONM changes were associated with POD (odds ratio 2.12; 95% CI 1.31-3.44; p < 0.001). Additionally, baseline EEG abnormalities were associated with POD (p = 0.002).

CONCLUSION

Significant IONM changes are associated with an increased risk of POD in patients undergoing cardiovascular surgery. These findings offer a basis for future research and analysis of EEG and somatosensory evoked potential monitoring to predict, detect, and prevent POD.

Early postoperative neurocognitive complications in elderly patients: comparing those with and without preexisting mild cognitive impairment- a prospective study

BACKGROUND

As societies age, increasing numbers of older adults undergo surgeries with anesthesia. Postoperative delirium (POD) and postoperative cognitive dysfunction (POCD) frequently occur in older surgical patients. Most of these patients already have preoperative mild cognitive impairment (MCI). However, the correlation between MCI and POD remains unclear. This study aimed to determine the incidence of POD in elderly patients with and without preexisting MCI.

METHODS

A prospective study enrolled patients aged 60 years and above scheduled for major surgeries between December 2017 and April 2022. Preoperative MCI was determined by a Montreal Cognitive Assessment (MoCA) score between 18 and 24. POD was diagnosed using criteria from the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). POCD was characterized by a MoCA score reduction of 2 or more points from the preoperative score. The primary outcome was the incidence of POD within the first 72 h postoperatively. Secondary outcomes encompassed other postoperative complications, including POCD.

RESULTS

The study comprised 223 elderly patients with MCI and 56 without MCI. The incidence of POD was 16.6% in the MCI group and 14.3% in the non-MCI group (P = 0.839). POCD occurred in 24.3% of MCI patients and 50% of non-MCI patients (P = 0.001). There were no significant differences in other postoperative complications between the groups. Postoperatively, the MCI group notably declined in visuospatial, attention, and orientation domains, while the non-MCI group declined in all domains except delayed recall.

CONCLUSIONS

The incidence of POD was similar in the MCI and non-MCI groups. However, the non-MCI group demonstrated a higher incidence of POCD than the MCI group. This was identified by a reduction in postoperative MoCA scores for the visuospatial, naming, attention, language, abstraction, and orientation domains. These findings underscore the importance of postoperative cognitive assessments for both elderly patients with preexisting MCI and those with previously intact cognitive functions.

TRIAL REGISTRATION

This trial was retrospectively registered in the Thai Clinical Trials Registry on 15/01/2019 (registration number: TCTR20190115001).

Effects of liposomal bupivacaine in preoperative fascia iliac block on postoperative pain and delirium in elderly patients undergoing hip fracture surgery: a study protocol for a randomised, parallel controlled prospective clinical study

INTRODUCTION

Postoperative delirium (POD) is the most common acute fluctuating mental state change after hip fractures in older adults. Postoperative pain is a Grade A risk factor for POD and is closely related to the prognosis of patients undergoing hip fracture surgery. The fascia iliac block has a definite analgesic effect and few side effects, and several studies have reported that it reduces the occurrence of POD in patients undergoing general anaesthesia for hip fracture surgery. Liposomal bupivacaine is a local anaesthetic with a long half-life that significantly reduces the use of opioids and is conducive to patient prognosis and recovery. However, whether regional nerve block analgesia can decrease the occurrence of POD in elderly patients undergoing hip fracture surgery has not been reported.

METHODS AND ANALYSIS

This is a single-blinded, randomised, parallel-controlled prospective clinical study. Participants will be randomly assigned preoperatively to either the liposomal bupivacaine (ie, Exparel) or ropivacaine groups by block randomisation. Then, the occurrence of POD (primary outcome) and postoperative pain (secondary outcome) will be evaluated.

ETHICS AND DISSEMINATION

This research protocol complies with the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) 2013 guidelines and is approved by the Ethics Committee of Shanghai General Hospital (ID 2023-437). The original data are expected to be released in July 2029 on the ResMan original data-sharing platform (IPD-sharing platform) of the China Clinical Trial Registry, which can be viewed on the following website: http://www.medresman.org.cn.

PROSPERO REGISTRATION NUMBER

ChiCTR2300074022.