Cognitive function after anaesthesia in the elderly

Relationship between intracranial pressure and neurocognitive function among older adults after radical resection of rectal cancer

BACKGROUND

Older patients are prone to postoperative cognitive decline after laparoscopic rectal cancer surgery, which may be associated with increased intraoperative intracranial pressure (ICP). This study investigated the correlation between intraoperative ICP changes, as indicated by measurements of the optic nerve sheath diameter (ONSD) using ultrasonography, and subsequent cognitive function to provide better patient care.

AIM

To evaluate changes in ICP and associated postoperative neurocognition in older adults after laparoscopic radical resection for rectal cancer.

METHODS

We included 140 patients who visited the Mianyang Central Hospital for malignant rectal tumors, measured their ONSDs before surgery and 30 and 60 minutes after the Trendelenburg position during surgery, and evaluated the patients’ cognitive function 1 day before surgery and 1, 4, and 7 days after surgery. The Mini-Mental State Examination (MMSE) and confusion assessment method (CAM) scores of the patients with different ONSDs were compared at different times after surgery.

RESULTS

In patients with an ONSD greater than 5.00 mm (group A1), the MMSE scores at 1 day and 4 days after surgery were significantly lower than those of patients with an ONSD less than or equal to 4.00 mm (group A2) (P < 0.05). The CAM scores of group A1 were significantly higher than those of group A2 (P < 0.05). The MMSE scores of group A1 on days 1 and 4 after surgery were significantly lower than those 1 day before and 7 days after surgery (P < 0.05), while the CAM scores 1 day and 4 days after surgery were significantly higher than those 1 day before and 7 days after surgery.

CONCLUSION

Decline in cognitive function among older adults after the procedure may be related to intracranial hypertension during surgery.

The Role of Intravenous Anesthetics for Neuro: Protection or Toxicity?

The primary intravenous anesthetics employed in clinical practice encompass dexmedetomidine (Dex), propofol, ketamine, etomidate, midazolam, and remimazolam. Apart from their established sedative, analgesic, and anxiolytic properties, an increasing body of research has uncovered neuroprotective effects of intravenous anesthetics in various animal and cellular models, as well as in clinical studies. However, there also exists conflicting evidence pointing to the potential neurotoxic effects of these intravenous anesthetics. The role of intravenous anesthetics for neuro on both sides of protection or toxicity has been rarely summarized. Considering the mentioned above, this work aims to offer a comprehensive understanding of the underlying mechanisms involved both in the central nerve system (CNS) and the peripheral nerve system (PNS) and provide valuable insights into the potential safety and risk associated with the clinical use of intravenous anesthetics.

Prospective comparison of three methods for detecting peri-operative neurocognitive disorders in older adults undergoing cardiac and non-cardiac surgery

Postoperative neurocognitive disorders occur frequently in older adult patients. Neuropsychological assessment is the gold standard for diagnosis, but the resources required for routine use are significant. Instead, it is common for simplified and unvalidated tests to be used for trials and in clinical practice. We undertook a single-centre prospective observational study in elective surgical patients aged ≥ 65 years recruited between September 2019 and January 2021. Patients underwent neuropsychological assessment, the Modified Telephone Interview for Cognitive Status and Montreal Cognitive Assessment before surgery. Tests were repeated at approximately four to eight postoperative weeks. We included 105 patients and 28 (27%) were lost to follow-up. Pre-operative Modified Telephone Interview for Cognitive Status and cognitive domain scores were very weakly to moderately correlated (r = 0.09-0.41). Pre-operative Montreal Cognitive Assessment and cognitive domain scores were very weakly to weakly correlated (r = 0.17-0.37) Postoperative Modified Telephone Interview for Cognitive Status and cognitive domain scores were very weakly to weakly correlated (r = 0.09-0.36). Postoperative Montreal Cognitive Assessment score and cognitive domain scores were very weakly to weakly correlated (r = 0.07-0.36). Overall, there was limited agreement between tests. We conclude that the Modified Telephone Interview for Cognitive Status and Montreal Cognitive Assessment should not be used in isolation to diagnose postoperative neurocognitive disorders. There seems to be little to no pre-operative, postoperative or pre- to postoperative correlation between these tests and the neuropsychological assessment in older adults without pre-operative cognitive impairment.

Peri-Operative Risk Factors Associated with Post-Operative Cognitive Dysfunction (POCD): An Umbrella Review of Meta-Analyses of Observational Studies

This umbrella review aimed to systematically identify the peri-operative risk factors associated with post-operative cognitive dysfunction (POCD) using meta-analyses of observational studies. To date, no review has synthesised nor assessed the strength of the available evidence examining risk factors for POCD. Database searches from journal inception to December 2022 consisted of systematic reviews with meta-analyses that included observational studies examining pre-, intra- and post-operative risk factors for POCD. A total of 330 papers were initially screened. Eleven meta-analyses were included in this umbrella review, which consisted of 73 risk factors in a total population of 67,622 participants. Most pertained to pre-operative risk factors (74%) that were predominantly examined using prospective designs and in cardiac-related surgeries (71%). Overall, 31 of the 73 factors (42%) were associated with a higher risk of POCD. However, there was no convincing (class I) or highly suggestive (class II) evidence for associations between risk factors and POCD, and suggestive evidence (class III) was limited to two risk factors (pre-operative age and pre-operative diabetes). Given that the overall strength of the evidence is limited, further large-scale studies that examine risk factors across various surgery types are recommended.

Frailty score and outcomes of patients undergoing vascular surgery and amputation: A systematic review and meta-analysis

Introduction

Frailty is associated with adverse postoperative health outcomes, including increased mortality, longer length of stay, higher rehospitalization, and other complications. There are many frailty assessment tools are to assess the level of frailty in vascular surgery patients. The aim of this study was to perform a systematic review and meta-analysis to assess the association between the frailty levels described by different frailty scores and adverse postoperative health outcomes among hospitalized vascular surgery patients and patients undergoing amputation.

Methods

Studies utilizing frailty scores and similar frailty assessment tools to describe frailty and investigate the association between frailty and health outcomes were searched. The primary outcomes of this study were in-hospital mortality, postdischarge mortality, length of hospital stay, rehospitalization, and discharge location. Additional outcomes included postoperative myocardial infarction, postoperative renal failure, cerebrovascular accident and stroke, comorbidities, and estimated glomerular filtration rate (eGFR) levels. Joanna Briggs Institute (JBI) Critical Appraisal Tools were used for quality assessment.

Results

In total, 24 studies with 1,886,611 participants were included in the final analysis. The overall results found that higher in-hospital mortality and postdischarge mortality were significantly associated with frailty. Frailty was also found to be significantly associated with a longer length of hospital stay, higher rehospitalization, and higher likelihood of non-home discharge. In addition, the results also showed that frailty was significantly associated with all kinds of comorbidities investigated, except chronic kidney disease. However, lower eGFR levels were significantly associated with frailty.

Conclusion

Among patients who underwent all types of vascular surgery and those who underwent amputations, assessment of frailty was significantly associated with adverse postoperative outcomes and multiple comorbidities.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=336374, identifier CRD42022336374.

Protective effects of chlorogenic acid on isoflurane-induced cognitive impairment of aged mice

Postoperative cognitive dysfunction (POCD) is characterized by impairment in cognitive functions in patients following anesthesia and surgery. Chlorogenic acid (CGA) is a plant-derived compound possessing numerous bioactive properties. The aim of this study was to investigate the therapeutic potential of CGA in isoflurane (ISO)-induced cognitive dysfunction of aged mice, and further identify the mechanisms involved in the protective effects of CGA. A total of 80 male C57BL/6 mice, 20-month-old, were randomly divided into control group, isoflurane group (ISO), and ISO + 30 mg/kg CGA group and ISO + 60 mg/kg CGA. CGA was given orally once daily for 7 days to the mice and they were exposed to ISO (1.5%; 4 h). The open-field and Morris water maze tests were used to investigate the cognitive function of mice. Pretreatment with CGA significantly attenuated ISO-induced cognitive impairment. The levels of IL-1β, TNF-α, IL-6, nuclear p65 NF-kB, cleaved caspase-3, and Bax were significantly increased, while the levels of IkBα and Bcl-2 were decreased in the hippocampus 24 h after the ISO anesthesia. All the mentioned effects induced by ISO were reversed by CGA pretreatment. Furthermore, ISO exposure induced marked downregulation of SOD, CAT, HO-1, and NQO-1 and elevation of MDA and nuclear translocation of Nrf2 in the hippocampus tissue. All these parameters were reversed by CGA treatment. Importantly, the higher dose of CGA (60 mg/kg) showed a greater neuroprotective effect. In conclusion, these findings suggest that CGA attenuates the ISO-induced cognitive impairment via its anti-inflammatory, anti-oxidative, and anti-apoptotic properties in aged mice.

Risk Factors for Acute Postoperative Delirium in Cardiac Surgery Patients >65 Years Old

Background: Acute postoperative delirium is the most common neuropsychiatric disorder in cardiac surgery patients in the intensive care unit (ICU). The purpose of this study was to evaluate the possible risk factors of postoperative delirium (POD) for cardiac surgery patients in the ICU. Materials and Methods: The study population was composed of 86 cardiac surgery patients managed postoperatively in the cardiac surgery ICU. Presence of POD in patients was evaluated by the CAM-ICU scale. Results: According to the CAM-ICU scale, 22 (25.6%) patients presented POD; history of smoking, alcohol use, COPD, and preoperative permanent atrial fibrillation were associated with POD (for all, p < 0.05). The type of cardiac surgery operations, type of analgesia, and red blood cell transfusion in the ICU were not associated with POD (p > 0.05), while cardiac arrhythmia in the ICU, hypoxemia in the ICU after extubation (pO2 < 60 mmHg), and heart rate after extubation were predisposing factors for POD (for all, p < 0.05). Multivariable logistic regression analysis (adjusted to risk factors) showed that hypoxemia after extubation (OR = 20.6; 95%CI: 2.82−150), heart rate after extubation (OR = 0.95; 95% CI: 0.92−0.98), and alcohol use (OR = 74.3; 95%CI: 6.41−861) were predictive factors for acute postoperative delirium (for all, p < 0.05). Conclusion: Alcohol use and respiratory dysfunction before and after heart operation were associated with acute postoperative delirium in cardiac surgery ICU patients.

Correlation between microRNA-320 and postoperative delirium in patients undergoing tibial fracture internal fixation surgery

Background

Although the incidence of postoperative delirium (POD) in the elderly after surgery are rising as individuals are living longer, the pathogenesis of POD remains poorly understood. It has been suggested that miRNA-320 may play a role in POD based on animal study and human study.

Methods

We first carried out an animal study, and designed and conducted a human study based on the result of animal study. The aged rats were randomly assigned to five groups: the control (C), anesthesia and surgery (AS), saline (NS), agomir-320 (AG), and antagomir-320 (AT) groups. Postoperative spatial learning and memory in rats were analyzed by the Morris water maze and the open field tests. The plasma levels of insulin-like growth factor-1 (IGF-1), amyloid precursor protein (APP) proteins, miRNA320 and IGF-1mRNA were measured by ELISA and qRT-PCR, respectively. A total of 240 Chinese Han patients over 65 years who underwent tibial fracture internal fixation were included in the PNDABLE study. POD cases and non-POD controls (1:1 matched) were selected by an anesthesiologist using Confusion Assessment Method.

Results

For Group AS, the escape latency was significantly longer and the ratio of time spent in the target quadrant was significantly reduced, APP and miR-320 were upregulated and IGF-1mRNA was downregulated compared with Group C. For Group AG, the escape latency was significantly longer and the ratio of time spent in the target quadrant was significantly reduced, APP and miR-320 were upregulated and IGF-1mRNA was downregulated compared with Group AS. For Group AT, the escape latency was significantly reduced and the ratio of time spent in the target quadrant was significantly longer, APP and miR-320 were downregulated and IGF-1mRNAwas upregulated compared with Group AS. Compared with NPOD patients, the expressions of plasma miR-320 and APP protein were increased and the expression of plasma IGF-1 mRNA was decreased in POD patients after surgery.

Conclusions

MiRNA-320 might play a role in up-regulating the levels of IGF-1mRNA and APP protein, which offered a new target for POD treatment.

Trial registration

Correlation of perioperative neurocognitive disorders with lifestyle and biomarkers. ChiCTR2000033439. Registered 1 June 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-022-01612-w.

Hypercholesterolemia aggravates sevoflurane-induced cognitive impairment in aged rats by inducing neurological inflammation and apoptosis

We aimed to explore the effects of hypercholesterolemia on sevoflurane-induced cognitive impairment in aged rats and the underlying mechanism(s). Aged rats were administrated with high-fat diet, sevoflurane, or both. Thereafter, the plasma levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) were evaluated. The Morris water maze task was performed to evaluate the spatial learning and memory ability of rats. Moreover, Nissl and Evans blue staining were conducted to test nerve damage and detect the blood-brain barrier permeability, respectively. The percentage of apoptotic cells was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling assay. The messenger RNA expression of inflammatory factors and protein expression of microglial activation markers and apoptosis-related proteins were tested by real-time polymerase chain reaction, enzyme-linked immunosorbent assay, or western blot analysis, respectively. High-fat diet induced high levels of TC, TG, and LDL but decreased levels of HDL. However, sevoflurane had no effects on these levels. In contrast, sevoflurane significantly induced the impairment of learning and memory, nerve damage, neuroinflammatory damage, and neuronal apoptosis. Hypercholesterolemia exacerbated the sevoflurane-induced impairment in aged rats. These results suggested that hypercholesterolemia aggravates sevoflurane-induced cognitive impairment in aged rats, possibly by inducing neurological inflammation and apoptosis.

Neurocognitive decline in cardiac surgery-Distraction rather than destruction?

BACKGROUND

A neurocognitive decline is an undesirable event that can be observed in patients after cardiac surgery. It has been related to the use of cardiopulmonary bypass (CPB). Minor embolic or hyperinflammatory mechanisms are thought to be responsible. In this issue of the Journal of Cardiac Surgery, the neurocognitive decline was observed in 22 of 30 patients after cardiac surgery with CPB. Repeatable neuropsychological status tests were used and scores 4 days after surgery were 5%-15% lower than before. Mechanistic investigations with glycemic control and transcriptomic and cytokine analyses failed to provide an explanation but the frequency of this observation is worrisome.

DISCUSSION

However, available evidence suggests that neurocognitive dysfunction disappears within a few months, and later on no difference to controls that did not undergo surgery can be detected. In addition, similar degrees of neurocognitive dysfunction can be observed after noncardiac surgery and even after percutaneous coronary intervention (PCI). A most recent comparison of memory decline after CABG and PCI also suggests no difference between the two invasive treatment options for coronary artery disease. All these findings argue against a primarily CPB-associated mechanism. Interestingly, test subjects from a consumer investigation showed a 10% decline in their working memory just by placing their cell phone on the table, suggesting that being distracted may also affect neurocognitive function. Given the reversibility of surgery- and intervention-associated neurocognitive dysfunction, we question destructive, embolic, or inflammatory-associated mechanisms. Distractive aspects of intervention-associated stress may also play a role.

CONCLUSION

In any case, neurocognitive decline after cardiac surgery does not appear to be surgery-specific.

Effects of dopamine transporter changes in the ventral tegmental area of the midbrain on cognitive function in aged rats

The pathogenesis of Perioperative neurocognitive disorders (PND) is a synergistic effect of many factors. Up to now, the exact mechanism remains unclear. The dopamine pathway in the brain is one of the paths involved in the means of cognitive function. Therefore, the purpose of this study was to investigate the relationship between changes in dopamine transporters in the ventral tegmental area (VTA) of the midbrain and postoperative cognitive dysfunction in elderly rats. In this study, a mental dysfunction model in elderly rats was established after splenectomy under general anesthesia. Eighty male SD rats, aged 18-20 months, with a body mass of 300-500 g. Randomly divided into eight groups: Normal group (Normal, N) and Sham group (sham, S), Model 3 day group(PND, P3), Model 7 day group(PND, P7), Virus 3 days AAV·DAT·RNAi (AAV3), Virus 7 days AAV·DAT·RNAi (AAV7), Virus control for three days AAV·NC(NC3), Virus control for seven days AAV·NC(NC7). The results show that knockdown of dopamine transporter in the VTA region can significantly improve the cognitive dysfunction of elderly rats after surgery. These results suggest that dopamine transporter in the VTA region is involved in cognitive dysfunction in elderly rats. The effect of DAT changes in the VTA region on postoperative cognitive function in elderly rats may be related to the regulation of α-syn and Aβ1-42 protein aggregation in the hippocampus.

Preoperative Cognitive Impairment as a Perioperative Risk Factor in Patients Undergoing Total Knee Arthroplasty

Background:

The study assessed whether pre-existing cognitive impairment (CI) prior to elective total knee arthroplasty (TKA) is associated with worse postoperative outcomes such as delirium, in-hospital medical complications, 30-day mortality, hospital length of stay and non-home discharge.

Methods:

A retrospective database analysis from the NSQIP Geriatric Surgery Pilot Project was used. There was an initial cohort of 6350 patients undergoing elective TKA, 104 patients with CI were propensity score matched to 104 patients without CI.

Results:

Analysis demonstrated a significantly increased incidence of post-operative delirium (POD) in the cohort with pre-op CI (p = < .001), a worsened functional status (p = < .001) and increased nonhome discharge postoperatively compared to the group without CI (p = 0.029). Other post-operative outcomes included 30-day mortality of 0% in both groups, and low rate of complications such as infection (2.88% vs 0.96%), pneumonia (1.92% vs 0%), failure to wean (0.96% vs 0%), and reintubation (0.96% vs 0%). Some other differences between the CI group and non-CI group, although not statistically significant, included increased rate of transfusion (10.58% vs 6.73%), and sepsis (1.92% vs 0%). The length of stay was increased in the non-CI group (4.28% vs 2.32%, p = 0.122).

Conclusion:

CI in patients undergoing TKA is associated with an increased risk of POD, worsened postoperative functional status, and discharge to non-home facility.

Short-term outcomes of sacrospinous hysteropexy through an anterior approach

INTRODUCTION AND HYPOTHESIS

The posterior approach to sacrospinous hysteropexy has been well studied but little is known about the anterior approach. This study assessed the efficacy and complications of an anterior approach to sacrospinous hysteropexy compared to hysterectomy with apical repair. We hypothesized that anterior sacrospinous hysteropexy has similar efficacy and fewer complications.

METHODS

This retrospective cohort study compared patients who underwent native-tissue anterior sacrospinous hysteropexy (cases) with those who underwent hysterectomy with apical repair (controls). Composite success was defined as (1) leading edge of prolapse not beyond the hymen and apex not descended > 1/3 total vaginal length; (2) no vaginal bulge symptoms; (3) no prolapse retreatment. Descriptive and bivariate statistics were performed as well as a Cox regression analysis for time to failure.

RESULTS

Fifty cases and 97 controls were compared. The median follow-up time was 7.6 months. Operative time was shorter in the hysteropexy group (110.7 vs. 155.9 min, p < 0.001). The composite success was 92% for both cases and controls (p = 1.000) with no difference in time to surgical failure (p = 0.183). There were no serious intraoperative complications in the hysteropexy group and six in the control group (3 transfusions, 1 conversion to laparotomy, 1 ureteral injury, 1 cystotomy; p = 0.101). There was no difference in the number of postoperative complications (22.0% vs. 30.9%, p = 0.203).

CONCLUSIONS

For primary uterine prolapse, anterior sacrospinous hysteropexy has similar short-term efficacy compared to hysterectomy with apical repair with shorter operative time and a trend towards fewer serious complications.

Dexmedetomidine Alleviates LPS-Induced Neuronal Dysfunction by Modulating the AKT/GSK-3β/CRMP-2 Pathway in Hippocampal Neurons

OBJECTIVE

Dexmedetomidine, an α2-adrenergic receptor agonist, mitigates cognitive dysfunction in elderly patients after surgery with general anesthesia. However, the underlying mechanism by which dexmedetomidine reduces cognitive dysfunction remains to be fully elucidated. The aim of this study was to investigate the effects of dexmedetomidine on lipopolysaccharide (LPS)-induced neuronal dysfunction in cultured hippocampal neurons.

METHODS

LPS, in the presence and absence of dexmedetomidine, was applied to cultured hippocampal neurons to mimic post-surgical inflammation. Neuronal morphology, including neurite outgrowth and synaptic transmission, was observed, and miniature excitatory postsynaptic currents were recorded by electrophysiological patch-clamp.

RESULTS

LPS significantly impaired neurite outgrowth in hippocampal neurons in a concentration- and time-dependent manner, which was reversed by dexmedetomidine treatment. Electrophysiological patch-clamp results showed that LPS induced synaptic transmission dysfunction, which was restored after dexmedetomidine addition. Furthermore, Western blotting assays showed that LPS suppressed the AKT/GSK-3β/CRMP-2 signaling pathway and dexmedetomidine countered the inhibitory effect of LPS by re-activating this pathway.

CONCLUSION

In general, dexmedetomidine protected against the effects of LPS-induced hippocampal neuron damage, including neurite outgrowth and synaptic transmission. Overall, dexmedetomidine modulated the AKT/GSK-3β/CRMP-2 signaling pathway to alleviate LPS-induced neurological dysfunction.

The effects of surgery on plasma vitamin C concentrations and cognitive function: a protocol for a prospective, observational study

BACKGROUND

Post-operative cognitive function has recently become an area of focus for researchers. The most commonly reported perioperative neurocognitive disorders include delirium and longer-lasting post-operative cognitive dysfunctions. The contributing pathophysiology to these complications remains unclear. A number of studies have systematically revealed a significant post-operative plasma vitamin C depletion. Recent insights have also exhibited a link between plasma vitamin C and numerous biological roles in brain function, with deficiencies potentially compromising cognitive function.

AIM

The present prospective, observational study will investigate whether there is a possible link between post-operative plasma vitamin C depletion and cognitive dysfunction.

METHODS

The cohort will consist of surgical patients, between the ages of 65 and 85 years, undergoing hip replacement surgery or a control group not exposed to surgical trauma. Participants will have their plasma vitamin C concentrations tested alongside a battery of computer-based cognitive assessments and paper and pen based cognitive tests. Further assessments will include dietary nutritional intake, serum vitamin B12 concentrations, cardiovascular biomarkers, wound healing, sleep quality, pain, mood and inflammatory cytokines. Participants will be tested at baseline (1-2 weeks prior to surgery) and subsequent testing sessions will be performed within 1 week, 4-6 weeks, 3 months and 6 months following surgery.

CONCLUSIONS

Findings from this observational study will provide insight into whether there is a concomitant depletion in post-operative plasma vitamin C concentrations and cognition function. Extrapolated results may prompt future, extensive randomized controlled trials to assess whether vitamin C supplementation can alleviate or even prevent post-operative cognitive complications.

Management of Common Postoperative Complications

Postoperative complications are common. Major guidelines have been published on stratifying and managing adverse cardiovascular events and thromboembolic events, but there is often less literature supporting management of other, more common, postoperative complications, including acute kidney injury, gastrointestinal complications, postoperative anemia, fever, and delirium. These common conditions are frequently seen in hospital and can contribute to longer lengths of stay and rising health care costs. These complications are often due to the interplay between both patient-specific and surgery-specific risk factors. Identifying these risk factors, while addressing and optimizing modifiable risks, can mitigate the likelihood of developing these postoperative complications. Often, a multidisciplinary approach, including care team members through all phases of the surgical encounter, is needed. Cardiovascular and thrombotic complications have been addressed in prior articles in this perioperative series. We aim to cover other common postoperative complications, such as acute renal failure, postoperative gastrointestinal complications, anemia, fever, and delirium that often contribute to longer lengths of stay, rising health care costs, and increased morbidity and mortality for patients.

Social Cognitive Dysfunction in Elderly Patients After Anesthesia and Surgery

Extensive studies have revealed that cognitive processing was impaired after anesthesia and surgery, particularly for the elderly patients. However, most of the existing studies focused on the general cognitive deficits (e.g., delayed neuro-cognitive recovery and POCD). Although diagnosis of social abilities has been used in various clinical fields, few studies have investigated the potential deficit on social cognition after anesthesia and surgery. The current study examined whether there was any social cognitive dysfunction after anesthesia and surgery. We achieved this by taking biological motion (BM) as the stimuli of interest, the perception of which has been taken as the hallmark of social cognition. The elderly patients (aged ≥ 60 years) were required to judge whether an upright BM stimulus appeared among the dynamic noises to test their social cognition, as well as do a Mini-Mental State Examination to test their general cognition. The two tests were performed at both 1-day before and 7-day after the surgery. Results showed that 31.25% of patients exhibited BM perception deficit after anesthesia and surgery relative to before anesthesia and surgery, implying that social cognitive dysfunction existed. Meanwhile, social cognitive dysfunction was independent from delayed neurocognitive recovery.

Outpatient, dental care of adult vulnerable patients under general anaesthesia-a retrospective evaluation of need for treatment and dental follow-up care

Objectives

To analyse the treatment needs of patients who had received dental treatment under GA and the effectiveness of the treatment provided.

Materials and methods

Retrospective chart analysis of adult at risk and vulnerable patients requiring dental treatment under GA (2007–2017). Outcome variables were indications for GA, DMF/T, and type of treatment, failure rates of treated teeth, emergencies and recall intervals after GA.

Results

Four hundred fourteen subjects (median age 42 years, range 18–93 years) were assigned to four groups (people with disabilities (pwdis), dementias (pwd), dental phobias (pwph), and addictions/psychosocial disorders (pwapd)) and attended the pre-GA assessment. Of these, 247 subjects (median 37 years, range 18–93 years) were treated under GA, mostly pwdis (n = 154, 69.7%). The main indication for treatment under GA was suspicion of pain (n = 178, 72.1%). Pwd had the highest degree of restoration (46.7%), DMF/T value (23.8), and most missing teeth (5.8). Pwapd had the most decayed teeth (12.9). There was a 12-month recall augmented by 2–4 oral hygiene sessions depending on compliance. The failure rate of all treated teeth was 4%. Two dental emergencies were reported for patients who received a GA.

Conclusions

Dental treatment need was high for adult vulnerable people. The diagnostic groups differed mainly in their subjective reason for need of a GA, their DMF/T, treatment needs and type of treatments performed. Failure and dental emergency rates after GA were low in spite of a recall interval of 12 months.

Clinical Relevance

Regular annual recalls could avoid dental emergencies in patients requiring treatment under GA.

Cognitive impairment assessment and interventions to optimize surgical patient outcomes

For elderly patients undergoing elective surgical procedures, preoperative evaluation of cognition is often overlooked. Patients may experience postoperative delirium (POD) and postoperative cognitive decline (POCD), especially those with certain risk factors, including advanced age. Preoperative cognitive impairment is a leading risk factor for both POD and POCD, and studies have noted that identifying these deficiencies is critical during the preoperative period so that appropriate preventive strategies can be implemented. Comprehensive geriatric assessment is a useful approach which evaluates a patient's medical, psycho-social, and functional domains objectively. Various screening tools are available for preoperatively identifying patients with cognitive impairment. The Enhanced Recovery After Surgery (ERAS) protocols have been discussed in the context of prehabilitation as an effort to optimize a patient's physical status prior to surgery and decrease the risk of POD and POCD. Evidence-based protocols are warranted to standardize care in efforts to effectively meet the needs of these patients.

Sevoflurane anesthesia-mediated oxidative stress and cognitive impairment in hippocampal neurons of old rats can be ameliorated by expression of brain derived neurotrophic factor

Postoperative cognitive dysfunction in elderly patients has been related to neurodegenerative disorders and mortality. Sevoflurane anesthesia has been implicated in both postoperative cognitive dysfunction and neurotoxicity. Given the advantages of using inhaled anesthetics like sevoflurane, it is important to understand how their usage results in neurotoxicity and subsequently devise ways to circumvent or attenuate the anesthetic-mediated induction in neurotoxicity. We have used an aged rat model to investigate the molecular mechanisms by which sevoflurane inhalation results in neurotoxicity and whether modulation of these molecular mechanisms can inhibit or attenuate neurotoxicity and cognitive learning and memory impairment in these animals. Low- or high-dose of sevoflurane resulted in reactive oxygen species generation, increased NADPH oxidase protein expression, apoptosis and autophagy. Sevoflurane inhalation resulted in significant inhibition of brain derived neurotrophic factor (BDNF) and cognitive impairment. And the activation of PI3K/Akt/mTOR signaling pathways are attenuated in sevoflurane-mediated anesthesia. Adeno-associated virus (AAV)-mediated expression of Bdnf, but not controls EGFP, attenuated sevoflurane-induced oxidative stress and cognitive impairment in the rats. Our results highlight that AAV-mediated gene therapy might offer a potential therapeutic opportunity to treat post-operative cognitive impairment resulting from inhaled anesthetics.

Electroacupuncture reduces astrocyte number and oxidative stress in aged rats with surgery-induced cognitive dysfunction

Objectives

To investigate the effects of electroacupuncture in regulating astrocytes and oxidative stress in a rat model of postoperative cognitive dysfunction (POCD).

Methods

Male aged Sprague-Dawley rats were randomized to undergo left hepatic lobe resection to induce POCD, followed by either electroacupuncture or no treatment; or similar surgery without left lobe resection or electroacupuncture (sham). Postsurgical cognitive function, hippocampal astrocyte number and oxidative stress indicators were measured.

Results

At days 1, 3 and 7 following surgery, escape latency was significantly shorter and platform crossing frequency was increased with electroacupuncture versus other groups. At postoperative day 1, the electroacupuncture group showed significantly fewer glial fibrillary acidic protein (GFAP)-positive hippocampal astrocytes versus the POCD model group. In POCD rats, electroacupuncture significantly decreased serum S100 calcium binding protein B and neuron-specific enolase levels, and increased brain-derived neurotrophic factor and glial cell-derived neurotrophic factor levels, at days 1, 3 and 7. Electroacupuncture significantly attenuated the hippocampal POCD-induced increase in malondialdehyde and decreased superoxide dismutase levels at day 1 following surgery.

Conclusion

Electroacupuncture may improve cognitive function in rats with POCD by reducing hippocampal GFAP-positive astrocyte number and suppressing oxidative stress.

Assessing the feasibility of using the Dalhousie Computerized Attention Battery to measure postoperative cognitive dysfunction in older patients

Purpose

Postoperative cognitive dysfunction is difficult to predict and diagnose, and can have severe consequences in the long term. The purpose of this study was to examine the feasibility of using a computerised test battery, the Dalhousie Computerized Assessment Battery in the perioperative clinic to detect cognitive changes after surgery.

Methods

Fifty patients were recruited for this study. Patients completed the Dalhousie Computerized Assessment Battery and tests of general cognition, mood and pain at baseline and at three months postoperatively.

Results

This pilot study had a screening rate (85.4%) and low attrition rate (12%). At baseline, patients exhibited no significant cognitive differences compared to a normative dataset. Postoperative cognitive dysfunction incidence was 2.7% on Montreal Cognitive Assessment, 13.6% with Dalhousie Computerized Assessment Battery and 36.3% based on subjective reports.

Conclusion

Computerised cognitive testing in the perioperative setting proved feasible. Deficits in spatial working memory and dual tasks may be most compromised by surgically related variables.

Microarray Expression Profiles of lncRNAs and mRNAs in Postoperative Cognitive Dysfunction

Postoperative cognitive dysfunction (POCD) is serious disorder in the central nervous system common in aged patients after anesthesia. Although its clinical symptoms are well recognized, however, the molecular etiology of the POCD remains unrevealed. Similarly, neither gold standard molecular diagnosis nor effective treatment is available for POCD until the present. Therefore, we aimed to explore the molecular mechanism of this disorder through investigating lncRNAs and mRNAs associated with POCD human patients and investigate their underlying regulatory pathways. In this study, we recruited 200 patients requiring hip or knee replacement surgery. Their neurological functions were assessed at two time points, 1 day before the surgery and 30 days post-surgery. In parallel, serum samples were collected from the participants to analyze lncRNAs and mRNAs differential expression profile between POCD and non-POCD patients using microarray analysis. To further investigate the role differentially expressed mRNA and lncRNAs, Gene Ontology (GO), pathway analyses on mRNAs and lncRNA-mRNA interaction network were performed. As a result, 68 lncRNAs and 115 mRNAs were dysregulated in the POCD group compared to non-POCD group. Among them, the top 10 upregulated lncRNAs and 10 downregulated lncRNAs were listed for enrichment analysis. Interestingly, we found that these lncRNA and mRNA are involved in biological process, molecular function, and cellular component in addition to various signaling pathways, suggesting that the pathogenesis of POCD involves lncRNAs and mRNAs differential expression. Consequently, the genetic dysregulation between the non-POCD and POCD patients participates in the occurrence and development of POCD, and could be served as diagnostic biomarkers and drug targets for POCD treatment.

Perioperative Research into Memory (PRiMe): Cognitive impairment following a severe burn injury and critical care admission, part 1

INTRODUCTION

An investigation into long-term cognitive impairment and Quality of Life (QoL) after severe burns.

METHODS

A proof of principle, cohort design, prospective, observational clinical study. Patients with severe burns (>15% TBSA) admitted to Burns ICU for invasive ventilation were recruited for psychocognitive assessment with a convenience sample of age and sex-matched controls. Participants completed psychological and QoL questionnaires, the Cogstate^® electronic battery, Hopkins Verbal Learning, Verbal Fluency and Trail making tasks.

RESULTS

15 patients (11M, 4F; 41±14 years; TBSA 38.4%±18.5) and comparators (11M, 4F; 40±13 years) were recruited. Burns patients reported worse QoL (Neuro-QoL Short Form v2, patient 30.1±8.2, control 38.7±3.2, p=0.0004) and cognitive function (patient composite z-score 0.01, IQR -0.11 to 0.33, control 0.13, IQR 0.47-0.73, p=0.02). Compared to estimated premorbid FSIQ, patients dropped an equivalent of 8 IQ points (p=0.002). Cognitive function negatively correlated with burn severity (rBaux score, p=0.04). QoL strongly correlated with depressive symptoms (Rho=-0.67, p=0.009) but not cognitive function.

CONCLUSIONS

Severe burns injuries are associated with a significant, global, cognitive deficit. Patients also report worse QoL, depression and post-traumatic stress. Perceived QoL from cognitive impairment was more closely associated with depression than cognitive impairment.

KIF17 mediates the learning and memory impairment in offspring induced by maternal exposure to propofol during middle pregnancy

Preclinical studies suggest that propofol may cause neuronal injury to the developing brain. A previous study demonstrated that, in a rat model, maternal exposure to propofol during early or late pregnancy caused learning and memory impairment in the offspring. However, whether propofol exposure during middle pregnancy can cause long‑term behavioral deficits in the offspring remains to be elucidated. N‑methyl‑D‑aspartate receptor 2B subunit (NR2B) serves a critical role in memory modulation. To exert its function, NR2B must be transported to the neuronal membrane by kinesin family member 17 (KIF17). The aim of the present study was to investigate the role of KIF17 in learning and memory impairment in rat offspring caused by propofol exposure during middle pregnancy. Pregnant rats were exposed to propofol on gestational day 14 (G14) for 4 and 8 h, with control pregnant rats receiving an equal volume of normal saline. The learning and memory of the offspring was assessed using Morris water maze tests from postnatal day 30 (P30) to P36. The levels of KIF17 protein, total NR2B (T‑NR2B) and membrane NR2B (M‑NR2B) in the hippocampus were detected using western blotting. The results demonstrated that propofol exposure caused learning and memory deficits and decreased KIF17 and M‑NR2B protein levels in the hippocampus; however, no but changes in the expression of T‑NR2B were observed. These results indicate that maternal propofol exposure during middle pregnancy impairs learning and memory in offspring rats by suppressing the expression of KIF17 and inhibiting the translocation of NR2B to the neuronal membrane.

Effect of Sevoflurane Anesthesia on Brain Is Mediated by lncRNA HOTAIR

Postoperative cognitive dysfunction in elderly patients has been related to neurodegenerative disorders and mortality. Sevoflurane anesthesia has been implicated in both postoperative cognitive dysfunction and neurotoxicity. Given the advantages of using inhaled anesthetics like sevoflurane, it is important to understand how their usage results in neurotoxicity and subsequently devise ways to circumvent or attenuate the anesthetic-mediated induction in neurotoxicity. Long noncoding RNAs (LncRNAs) are a group of > 200 bp long RNAs and show specific spatiotemporal expression profiles. Several recent reports suggest that lncRNAs are involved in responses of the central nervous system (CNS) following acute injuries. However, their role in sevoflurane anesthesia-mediated cognitive dysfunction has not been studied. RNA immunoprecipitation (RIP) combined with qRT-PCR detection of six different lncRNAs showed that the HOTAIR lncRNAs were significantly more bound to both Sin3A and coREST, both corepressors of the RE-1 silencing transcription factor, within rat hippocampus following sevoflurane anesthesia compared with sham. Sevoflurane inhalation resulted in significant inhibition of brain-derived neurotrophic factor (BDNF) and cognitive impairment. Treatment with a combination of siRNAs targeting HOTAIR rescued BDNF expression and improved cognitive responses. Taken together, our results suggest that sevoflurane-mediated brain function impairment is at least in part mediated by the HOTAIR lncRNA.

Effect of dexmedetomidine-induced anesthesia on the postoperative cognitive function of elder patients after laparoscopic ovarian cystectomy

Objective

To investigate the effect of dexmedetomidine at maintenance dose on the postoperative function of elder patients after general anesthesia for laparoscopic ovarian cystectomy.

Methods

We enrolled a total of 96 elder patients who were admitted to this hospital for laparoscopic ovarian cystectomy under general anesthesia between March 2015 and March 2017, and divided them into two groups, Group A (n = 48) and B (n = 48). Patients in both groups received the same methods for anesthesia induction and maintenance drugs. At the beginning of operation, patients in Group A received the intravenous injection of dexmedetomidine (0.8 μg/kg) followed by maintenance dose [0.5 μg/(kg h)] to the end of operation, while those in Group B underwent intravenous injection of 0.9% normal saline at the same rate, during which blood pressure, heart rate, oxyhemoglobin saturation and dosage of anesthetics at T1 (5 min after being delivered into the operation room), T2 (immediately after anesthesia induction), T3 (immediately after intubation), T4 (immediately after operation), T5 (immediately after end of operation) and T6 (immediately after extubation). Then, the levels of NSE, IL-6, CRP and HMGB1 were compared between two groups at 24 h before the operation, at the end, 24 h, 3 d and 7 d after operation. Besides, we also compared the postoperative cognitive functions and incidence of adverse reactions at 1 d before, 1, 2, 3 and 7 d after operation through MOCA scales.

Results

At T3, T4 and T6, comparisons of the average arterial pressure and heart rate showed that the differences between the two groups had statistical significance (p < .05). At the end of operation, and at 24 h, 3 d and 7 d after operation, we found that the levels of IL-6 and CRP in patients of two groups were all significantly elevated when compared with those before operation; at the end of operation and at 24 h and 3 d after operation, the levels of IL-6 and CRP in the Group B were higher than those in the Group A, and the differences had statistical significance (p < .05). At the end of operation and at 24 h and 3 d after operation, the levels of NSE and HMGB1 in two group were higher than those before operation, and a more significant elevation was identified in Group B with statistically significant differences (p < .05); at 7 d after operation, a decreasing trend was found in the level of HMGB1, which, however, remained higher than the preoperative level, and the level in Group B was still higher than that in Group A with statistically significant differences (p < .05). At 2 d after operation, we found that the scores of MOCA in the Group B were remarkably decreased in comparison with the scores in Group A with a statistically significant difference (p < .05). Moreover, the incidence rate of postoperative cognitive dysfunction (POCD) in the Group A was significantly lower than that in the Group B, and the difference had statistical significance (p < .05).

Conclusion

Dexmedetomidine can ameliorate the postoperative cognitive functions of elder patients who received the laparoscopic ovarian cystectomy under general anesthesia, and effectively decrease the incidence rate of POCD without any obvious or severe adverse reaction. Thus, it can serve as a kind of adjuvant drug for general anesthesia in clinical practice.

A Retrospective Observational Study of Anesthetic Induction Dosing Practices in Female Elderly Surgical Patients: Are We Overdosing Older Patients?

BACKGROUND/OBJECTIVES

Despite guidelines suggesting a 25-50 % reduction in induction doses of intravenous anesthetic agents in the elderly (≥65 years), we hypothesized that practitioners were not sufficiently correcting drug administration for age, contributing to an increased incidence of hypotension in older patients undergoing general anesthesia.

STUDY DESIGN

We conducted a retrospective, observational study in a tertiary-care academic hospital. The study included 768 female patients undergoing gynecologic surgeries who received propofol-based induction of general anesthesia.

MAIN OUTCOME MEASURES

Weight-adjusted anesthetic induction dosing, age-associated differences in dosing by ASA-PS (American Society of Anesthesiology-Physical Status), and hemodynamic outcomes between younger (18-64 years, n = 537) and older (≥65 years, n = 231) female patients were analyzed.

RESULTS

Older patients received lower doses of propofol and midazolam than younger patients (propofol: 2.037 ± 0.783 vs 2.322 ± 0.834 mg/kg, p < 0.001; midazolam: 0.013 ± 0.014 vs 0.023 ± 0.042 mg/kg, p < 0.001). However, practitioners still consistently exceeded the FDA recommended dose (1-1.5 mg/kg) of propofol for elderly patients. There was no significant difference in the doses of fentanyl administered between the two age groups (1.343 ± 0.744 vs 1.363 ± 0.763 μg/kg, p = 0.744), and doses of fentanyl in older patients exceeded the recommended dose (0.5-1.0 μg/kg). Corresponding to observed overdosing of induction agents, older patients experienced larger decreases in post-induction blood pressure and were more likely to receive vasopressor therapy.

CONCLUSIONS

Anesthetic induction doses of fentanyl and propofol were not sufficiently corrected in older patients in accordance with recommendations. Significantly greater frequency of post-induction hypotension occurred amongst older patients. Quality improvement efforts may lead to improved outcomes in this vulnerable population.

Perioperative prediction of agitated (hyperactive) delirium after cardiac surgery in adults - The development of a practical scorecard

BACKGROUND

Delirium is a temporary mental disorder that occurs frequently among hospitalized patients. In this study we sought to develop a user-friendly scorecard based on perioperative features to identify patients at risk of developing agitated delirium after cardiac surgery.

METHODS

Retrospective analysis was performed on adult patients undergoing cardiac surgery in a single center. A parsimonious predictive model was created, with subsequent internal validation. Then a simple scorecard was developed that can be used to predict the probability of agitated delirium.

RESULTS

Among the 5584 patients who met the study criteria, 614 (11.4%) developed postoperative agitated delirium. Independent predictors of postoperative agitated delirium were age, male gender, history of cerebrovascular disease, procedure other than isolated Coronary Arteries Bypass Surgery, transfusion of blood products within the first 48h, mechanical ventilation for >24h, length of stay in the Intensive Care Unit. The scorecard stratified patients into 4 categories at risk of postoperative agitated delirium ranging from <5% to >30%.

CONCLUSION

Using a large cohort of adult patient's undergoing cardiac surgery, a user-friendly scorecard was developed and validated, which will facilitate the implementation of timely interventions to mitigate adverse effects of agitated delirium in this high risk population.

The Alarmin HMGB1 Mediates Age-Induced Neuroinflammatory Priming

Amplified neuroinflammatory responses following an immune challenge occur with normal aging and can elicit or exacerbate neuropathology. The mechanisms mediating this sensitized or "primed" immune response in the aged brain are not fully understood. The alarmin high mobility group box 1 (HMGB1) can be released under chronic pathological conditions and initiate inflammatory cascades. This led us to investigate whether HMGB1 regulates age-related priming of the neuroinflammatory response. Here, we show that HMGB1 protein and mRNA were elevated in the hippocampus of unmanipulated aged rats (24-month-old F344XBN rats). Furthermore, aged rats had increased HMGB1 in the CSF, suggesting increased HMGB1 release. We demonstrate that blocking HMGB1 signaling with an intracisterna magna (ICM) injection of the competitive antagonist to HMGB1, Box-A, downregulates basal expression of several inflammatory pathway genes in the hippocampus of aged rats. This indicates that blocking the actions of HMGB1 might reduce age-associated inflammatory priming. To test this hypothesis, we evaluated whether HMGB1 antagonism blocks the protracted neuroinflammatory and sickness response to peripheral Escherichia coli (E. coli) infection in aged rats. ICM pretreatment of aged rats with Box-A 24 h before E. coli infection prevented the extended hippocampal cytokine response and associated cognitive and affective behavioral changes. ICM pretreatment with Box-A also inhibited aging-induced potentiation of the microglial proinflammatory response to lipopolysaccharide ex vivo Together, these results suggest that HMGB1 mediates neuroinflammatory priming in the aged brain. Blocking the actions of HMGB1 appears to "desensitize" aged microglia to an immune challenge, thereby preventing exaggerated behavioral and neuroinflammatory responses following infection.

SIGNIFICANCE STATEMENT

The world's population is aging, highlighting a need to develop treatments that promote quality of life in aged individuals. Normal aging is associated with precipitous drops in cognition, typically following events that induce peripheral inflammation (e.g., infection, surgery, heart attack). Peripheral immune stimuli cause exaggerated immune responses in the aged brain, which likely underlie these behavioral deficits. Here, we investigated whether the alarmin high mobility group box 1 (HMGB1) mediates age-associated "priming" of the neuroinflammatory response. HMGB1 is elevated in aged rodent brain and CSF. Blocking HMGB1 signaling downregulated expression of inflammatory pathway genes in aged rat brain. Further, HMGB1 antagonism prevented prolonged infection-induced neuroinflammatory and sickness responses in aged rats. Overall, blocking HMGB1 "desensitized" microglia in the aged brain, thereby preventing pathological infection-elicited neuroinflammatory responses.

A mutation in β-amyloid precursor protein renders SH‑SY5Y cells vulnerable to isoflurane toxicity: The role of inositol 1,4,5‑trisphosphate receptors

Isoflurane is a commonly used inhaled anesthetic, which induces apoptosis of SH-SY5Y cells in a dose- and time-dependent manner; however, the underlying mechanisms remain unknown. The authors of the present study hypothesized that a mutation in β-amyloid precursor protein (APP), which is a gene associated with familial Alzheimer's disease, may render cells vulnerable to isoflurane-induced cytotoxicity via activation of inositol 1,4,5-trisphosphate receptors (IP3R). In the present study, SH-SY5Y cells were transfected with a vector or with mutated APP, and were treated with the equivalent of 1 minimum alveolar concentration (MAC) isoflurane for 8 h. Cell apoptosis rate, alterations to cytosolic calcium concentrations ([Ca²⁺]c), and protein levels of IP3R were determined following exposure of cells to isoflurane. In addition, the effects of the IP3R antagonist xestospongin C were determined on isoflurane-induced cytotoxicity and calcium release from the endoplasmic reticulum (ER) of mutated APP- and vector-transfected SH-SY5Y cells. Treatment with isoflurane (1 MAC) for 8 h induced a higher degree of cytotoxicity, and a marked increase in [Ca²⁺]c and IP3R protein levels in mutated APP-transfected SH-SY5Y cells compared with vector-transfected SH-SY5Y cells. Xestospongin C significantly attenuated isoflurane-mediated cytotoxicity and inhibited calcium release from the ER of SH-SY5Y cells. These results indicated that the APP mutation may render SH-SY5Y cells vulnerable to isoflurane neurotoxicity, and the underlying mechanism may be associated with Ca²⁺ dysregulation via overactivation of IP3R.

Risk factors of post-operative delirium after elective vascular surgery in the elderly: A systematic review

BACKGROUND

Postoperative delirium is a common and serious adverse event in the elderly patient and is associated with significant morbidity and mortality. It is of great importance to identify patients at risk for delirium, in order to focus preventive strategies. The aim of this article is to systematically review current available literature on pre-operative risk factors for delirium after vascular surgery.

METHODS

A systematic literature search was conducted using PubMed and EMBASE, using the MeSH terms and key words "delirium", "surgery" and "risk factor". Studies were retained for review after meeting strict inclusion criteria that included only prospective studies evaluating risk factors for delirium in patients who had elective vascular surgery. Diagnosis of delirium needed to be confirmed using the Diagnostic and Statistical Manual of Mental Disorders (DSM) or ICD-10.

RESULTS

Fifteen articles were selected for inclusion, incidence of delirium across the studies ranged from 5% to 39%. Many factors have been associated with increased risk of delirium, including age, cognitive impairment, comorbidity, depression, smoking, alcohol, visual and hearing impairment, ASA-score, biochemical abnormalities, operative strategies and blood loss.

CONCLUSIONS

Delirium is a common complication after elective vascular surgery in elderly. The highest delirium incidence was observed after open aortic surgery as well as after surgery for critical limb ischemia. A picture starts to form of which predisposing factors lead to increased risk of delirium. The leading risk factors consistently identified in this systematic review were advanced age and cognitive impairment. Multi-disciplinary specialist-led interventions in the preoperative phase could decrease incidence and severity of delirium and should be focused on identified high-risk patients.

Post-operative cognitive dysfunction at 3 months in adults after non-cardiac surgery: a qualitative systematic review

BACKGROUND

Post-operative cognitive dysfunction is defined as a decline in cognitive functions that occurs after surgery, but different diagnostic criteria and incidences have been reported in medical literature. Our aim was to determine incidence of post-operative cognitive dysfunction 3 months after non-cardiac surgery in adults.

METHODS

A systematic review of available evidence was performed by PRISMA guidelines. A search was done in May-July 2015 on PubMed, EMBASE, CINAHL, LILACS, Scielo, Clinical Trials, and Grey Literature Reports. Inclusion criteria were prospective design studies with patients over 18 years old, surgery under general or regional anesthesia, follow-up for 3 months, and use of a neurocognitive battery for diagnosis. We excluded studies made on cardiac or brain surgery patients. Risk of bias was assessed using tools from National Heart Lung and Blood Institute.

RESULTS

We selected 24 studies. Average age was 68 years. Only five studies reported incidence of cognitive decline for a non-surgical control group. Median number of tests used was 5 (range 3-13). Pooled incidence of post-operative cognitive dysfunction at 3 months was 11.7% [95% CI 10.9-12.5] but with several methodological differences between studies. Increasing age was the most consistent risk factor identified (seven studies).

CONCLUSIONS

Post-operative cognitive dysfunction in patients is frequent, especially in patients over 60 years old. Limitations include methodological differences in studies. Efforts must be made to reach a consensus in definition and diagnosis for future research.

Approach to Evaluating the Multimorbid Patient with Cardiovascular Disease Undergoing Noncardiac Surgery

Older patients undergo more inpatient and outpatient procedures than do younger individuals, and their risk of suffering undesired outcomes is greater. The performance of a productive preoperative assessment entails more than the application of the sundry clinical practice guidelines relating to a patient's various medical diagnoses. A better approach involves adoption of a physiologically integrated, whole-person assessment that takes into account the patient's cognitive function, mood, physical function and mobility (including the possibility of frailty), social support, nutritional status, and medication use. This article outlines such an approach and highlights the many gaps in the current evidence base.

TNF-α receptor antagonist attenuates isoflurane-induced cognitive impairment in aged rats

Postoperative cognitive dysfunction (POCD), a common clinical in aged patients, is characterized by deficits in cognitive functions in patients following anesthesia and surgery. It has been demonstrated that isoflurane may lead to cognitive impairment in aged rats; however, effective clinical interventions for preventing this disorder are limited. Tumor necrosis factor (TNF)-α has been suggested to be involved in neuroinflammation as well as the development of POCD. Accordingly, the present study aimed to investigate whether TNF-α signaling is involved in the isoflurane-induced cognitive impairment in aged rats, and whether TNF-α receptor antagonist are able to attenuate isoflurane-induced cognitive impairment in aged rats. A population of 20-month-old rats were administered TNF-α receptor antagonist R-7050 or an equal volume of saline by intraperitoneal injection 12 h prior to exposure to isoflurane to model cognitive impairment following anesthesia in old patients. Then the rats were exposed to 1.3% isoflurane for 4 h. In the control group, rats showed impaired cognitive functions evaluated by Morris water maze assay after isoflurane exposure. Furthermore, isoflurane exposure induced marked upregulation of proinflammatory cytokines, including interleukin (IL)-1β, TNF-α, IL-6 and IL-8 in the hippocampus tissue. In the experimental group, intracisternal administration of TNF-α receptor antagonist R-7050 significantly attenuated isoflurane-induced cognitive impairment and upregulation of proinflammatory cytokines. Further investigation revealed that intracisternal administration of TNF-α receptor antagonist R-7050 notably suppressed isoflurane-induced activation of NF-κB and MAPK signaling. Collectively, the present results suggest that TNF-α receptor antagonist may serve as a potential agent for the prevention of anesthesia-induced cognitive decline in aged patients.

Assessment of selected cognitive processes in elderly patients after urologic surgery

INTRODUCTION

The issue of postoperative disorders of cognitive functions is a highly topical problem as more and more elderly people undergo medical treatments. Patients may lose the ability of assimilating information and their linguistic functions may deteriorate. Cognitive disorders may result in the temporary exclusion of the patient from social activity.

AIM

The purpose of the paper was to assess the incidence of certain cognitive disorders in the elderly after urological surgeries.

MATERIAL AND METHODS

The study was conducted in a group of 218 patients aged over 65, male and female, after an urological surgery under different types of anesthesia. Standardized neuropsychological tests of cognitive functions were employed in the study.

RESULTS

Analysis of the data showed that in the control group were obtained similar results in the study of the first and second. However, in the test group demonstrated a reduction cognitive function in all the tests in a second study.

CONCLUSIONS

The reduction of cognitive functions in the study group was observed in all the domains but it was the most marked in visual memory tests. Postoperative reduction of cognitive functions is correlated with the patient's age, education and mood. Postoperative reduction of cognitive functions is not correlated with the type of surgery, anesthesia and its duration.

Selective impairment of attention networks during propofol anesthesia after gynecological surgery in middle-aged women

BACKGROUND

Postoperative cognitive dysfunction is a common complication of anesthesia and surgery. Attention networks are essential components of cognitive function and are subject to impairment after anesthesia and surgery. It is not known whether such impairment represents a global attention deficit or relates to a specific attention network. We used an Attention Network Task (ANT) to examine the efficiency of the alerting, orienting, and executive control attention networks in middle-aged women (40-60 years) undergoing gynecologic surgery. A matched group of medical inpatients were recruited as a control.

METHODS

Fifty female patients undergoing gynecologic surgery (observation group) and 50 female medical inpatients (control group) participated in this study. Preoperatively patients were administered a mini-mental state examination as a screening method. The preoperative efficiencies of three attention networks in an attention network test were compared to the 1st and 5th post-operative days.

RESULTS

The control group did not have any significant attention network impairments. On the 1st postoperative day, significant impairment was shown in the alerting (p=0.003 vs. control group, p=0.015 vs. baseline), orienting (p<0.001 vs. both baseline level and control group), and executive control networks (p=0.007 vs. control group, p=0.002 vs. baseline) of the observation group. By the 5th postoperative day, the alerting network efficiency had recovered to preoperative levels (p=0.464 vs. baseline) and the orienting network efficiency had recovered partially (p=0.031 vs. 1st post-operative day), but not to preoperative levels (p=0.01 vs. baseline). The executive control network did not recover by the 5th postoperative day (p=0.001 vs. baseline, p=0.680 vs. 1st post-operative day).

CONCLUSIONS

Attention networks of middle-aged women show a varying degree of significant impairment and differing levels of recovery after surgery and propofol anesthetic.

Intranasal Insulin Prevents Anesthesia-Induced Spatial Learning and Memory Deficit in Mice

Elderly individuals are at increased risk of cognitive decline after anesthesia. General anesthesia is believed to be a risk factor for Alzheimer’s disease (AD). At present, there is no treatment that can prevent anesthesia-induced postoperative cognitive dysfunction. Here, we treated mice with daily intranasal administration of insulin (1.75 U/day) for one week before anesthesia induced by intraperitoneal injection of propofol and maintained by inhalation of sevoflurane for 1 hr. We found that the insulin treatment prevented anesthesia-induced deficit in spatial learning and memory, as measured by Morris water maze task during 1–5 days after exposure to anesthesia. The insulin treatment also attenuated anesthesia-induced hyperphosphorylation of tau and promoted the expression of synaptic proteins and insulin signaling in the brain. These findings show a therapeutic potential of intranasal administration of insulin before surgery to reduce the risk of anesthesia-induced cognitive decline and AD.

Melatonin pretreatment prevents isoflurane-induced cognitive dysfunction by modulating sleep-wake rhythm in mice

BACKGROUND

Sleep plays an important role in memory processing. However, its role in anesthesia-induced cognitive dysfunction was not revealed. Our study sought to investigate the connection between the cognition decline and sleep-wake rhythm disorders after long-term isoflurane anesthesia in mice. Also, we examined the effect of exogenous melatonin pretreatment on both cognitive function and circadian rhythm. Furthermore, we discussed whether NR2B (N-methyl-D-aspartate receptor 2B subunit)-CREB (cAMP-response element binding protein) signaling pathway was involved in this course.

METHODS

2-month-old male C57/BL-6J mice were submitted to long-term anesthesia using 1% isoflurane from CT (Circadian Time) 14 to CT20. Melatonin pretreatment were conducted before anesthesia for 7 Days. Intellicage for mice and Mini-Mitter were applied to monitor spatial memory and gross motor activity which can reflect cognition and sleep-wake rhythm. Messenger RNA and protein expression of right hippocampus NR2B and CREB were examined by RT-PCR and Western blot.

RESULTS

6h isoflurane anesthesia led to impaired spatial memory from Day 3 to Day 10 in mice accompanied by the disruption of sleep-wake rhythm. Meanwhile, the hippocampus CREB and NR2B expression declined in step. Melatonin pretreatment ameliorated disturbed sleep-wake cycle, improved isoflurane-induced cognitive dysfunction, and reversed the down-regulation of CREB and NR2B expression.

CONCLUSIONS

Our data demonstrate that sleep-wake rhythm is involved in the isoflurane-induced cognition impairment and pretreatment of melatonin has a positive effect on circadian normalization and cognition reversal. Also, NR2B-CREB signaling pathway has a critical role in this process. This study provides us a new strategy for anesthesia-induced cognitive dysfunction therapy.