Does anaesthesia cause postoperative cognitive dysfunction? A randomised study of regional versus general anaesthesia in 438 elderly patients

Effect of sugammadex versus neostigmine/atropine combination on postoperative cognitive dysfunction after elective surgery

This study aimed to assess the effects of sugammadex and neostigmine/atropine on postoperative cognitive dysfunction (POCD) in adult patients after elective surgery. A randomised, double-blind controlled trial was carried out on 160 American Society of Anesthesiologists physical status I to III patients who were >40 years. The Mini-Mental State Evaluation, clock-drawing test and the Isaacs Set test were used to assess cognitive function at three timepoints: 1) preoperatively, 2) one hour postoperatively, and 3) at discharge. The anaesthetic protocol was the same for all patients, except for the neuromuscular block reversal, which was administered by random allocation using either sugammadex or neostigmine/atropine after the reappearance of T2 in the train-of-four sequence. POCD was defined as a decline ≥1 standard deviation in ≥2 cognitive tests. The incidence of POCD was similar in both groups at one hour postoperatively and at discharge (28% and 10%, in the neostigmine group, 23% and 5.4% in the sugammadex group, P=0.55 and 0.27 respectively). In relation to individual tests, a significant decline of clock-drawing test in the neostigmine group was observed at one hour postoperatively and at discharge. For the Isaacs Set test, a greater decline was found in the sugammadex group. These findings suggest that there are no clinically important differences in the incidence of POCD after neostigmine or sugammadex administration.

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

PURPOSE

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

DESIGN

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

METHODS

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

FINDINGS

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

CONCLUSIONS

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

Perioperative Care of Elderly Surgical Outpatients

The ambulatory setting offers potential advantages for elderly patients undergoing elective surgery due to the advancement in both surgical and anesthetic techniques resulting in quicker recovery times, fewer complications, higher patient satisfaction, and reduced costs of care. This review article aims to provide a practical guide to anesthetic management of elderly outpatients. Important considerations in the preoperative evaluation of elderly outpatients with co-existing diseases, as well as the advantages and disadvantages of different anesthetic techniques on a procedural-specific basis, and recommendations regarding the management of common postoperative complications (e.g., pain, postoperative nausea and vomiting [PONV], delirium and cognitive dysfunction, and gastrointestinal dysfunction) are discussed. The role of anesthesiologists as perioperative physicians is important for optimizing surgical outcomes for elderly patients undergoing ambulatory surgery. The implementation of high-quality, evidence-based perioperative care programs for the elderly on an ambulatory basis has assumed increased importance. Optimal management of perioperative pain using opioid-sparing multimodal analgesic techniques and preventing PONV using prophylactic antiemetics are key elements for achieving enhanced recovery after surgery.

Early and long-term cognitive outcome after conventional cardiac valve surgery

Objectives

Adverse cognitive outcome is well recognized after coronary artery bypass grafting (CABG) while little is known about the extent and duration of decline after cardiac valve surgery. We investigated changes in cognitive function following conventional cardiac valve surgery over up to 4 years.

Methods

Among 36 patients (65.2 ± 9.2 years, 36% women) who received valve surgery, we assessed serial cognitive function with a battery of 11 standardized tests across 3-4 years. Cognitive function was analysed to identify: (1) cognitive decline (i.e. within-patient changes in test scores) and (2) cognitive deficit (i.e. drop of score ≥1 SD in ≥3 tests). Diffusion-weighted magnetic resonance imaging (DW-MRI) was applied pre- and post-procedure to detect ischaemic brain injury. Data were compared to a historical cohort of 39 patients undergoing CABG.

Results

After both valve surgery and CABG, a significant decline at discharge was detected in 7 of 11 cognitive tests. The rate of patients with a cognitive deficit after valve surgery vs CABG was 39% vs 56% at discharge, 14% vs 23% at 3 months, and 16% vs 26% at 3-4 years (not significant, [n.s.]). After valve surgery, DW-MRI identified 19 (53%) patients with evidence of 50 new focal ischaemic lesions (CABG: 20 [51%] patients with 42 lesions, n.s.). Cumulative cerebral ischaemic load per patient was not significantly different between the valve surgery group and CABG group (503 ± 485 mm 3 vs 415 ± 234 mm 3 ). After correction for multiple potential risk factors in both groups, reduced verbal memory at discharge could be identified as a predictor of long-term cognitive impairment in CABG patients only ( P  = 0.04). For both the valve surgery and CABG group, no association between cognitive impairment and new ischaemic cerebral lesions was found.

Conclusions

The course of cognitive performance after valve surgery and CABG was similar with early postoperative decline followed by subsequent recovery. Although silent small brain infarcts were present in about half of all patients, they did not impact cognitive performance neither at early nor during long-term follow-up.

[Cognitive dysfunction and content of inflammatory markers in patients after coronary artery bypass graft]

AIM

To study the relationship between the content of inflammatory biomarkers and cognitive function in patients after coronary artery bypass graft (CABG) performed in condition of artificial blood circulation (ABC) or open-heart surgery (OHS).

MATERIAL AND METHODS

Twenty-nine patients with ischemic heart disease who survived CABG, mean age 62.4±6.2 years, were studied. The ABC group (n=18) and OHS group (n=11) were matched for age and sex. Patients underwent standard clinical examination as well as neurological examination and neuropsychological testing. Concentrations of pro- and anti-inflammatory cytokines (IL-1β, IL-2, IL-4, IL-6, IL-10, IL-12, IL-17, IL-1RA, IFN-γ, IP-10; MCP-1, MIP-1α, MIP-1β, RANTES, TNF) were determined in blood plasma obtained 24 h before and 2h after surgery using multiplex immunofluorescence assay.

RESULTS

In both groups, an increase in concentrations of IL-6, IL-8, IL-10, IL-12, IP-10, MCP-1, MIP-1β and RANTES was observed at point T1. Concentration of IL-1RA was significantly higher only in the ABC group but not in the OHS group. After CABG, an increase in concentrations of IL-8, IP-10, MIP-1β, IL-1RA was significantly higher in the ABC group. The Montreal scale was the most sensitive test for assessment of cognitive functions in post CABG patients. A significant decrease in scores (>3) was noted in 8 out of 18 patients in the ABC group and in one patient of the OHS group. The correlations between the decrease in cognitive functioning in the 7th day after surgery and plasma cytokine concentration 2 h after surgery were identified for IL-6 (r=0.472; p=0.01); IL-8 (r=0.403; p=0.03); IP-10 (r=0.372; p=0.047); MCP-1 (r=0.470; p=0.01).

CONCLUSION

CABG is accompanied by the systemic inflammatory reaction, with the more marked inflammatory effect in patients operated under condition of extracorporeal circulation. CABG with ABC causes an impairment of cognitive functions during the first week in many patients. Impaired cognitive status was associated with the increase in concentrations of proinflammatory cytokines in blood plasma.

Mind Over Matter? The Hidden Epidemic of Cognitive Dysfunction in the Older Surgical Patient

OBJECTIVE

The aim of this study was to highlight the vulnerability of the aging brain to surgery and anesthesia, examine postoperative cognitive outcomes, and recommend possible interventions.

BACKGROUND

Surgeons are facing increasingly difficult ethical and clinical decisions given the rapidly expanding aging demographic. Cognitive function is not routinely assessed either preoperatively or postoperatively. Potential short and long-term cognitive implications are rarely discussed with the patient despite evidence that postoperative cognitive impairment occurs in up to 65% of older patients. Furthermore, surgery may accelerate the trajectory of cognitive decline and dementia.

METHODS

An electronic search was conducted using Pubmed/Medline. References from selected studies were cross-referenced and relevant articles retrieved. Data were summarized in a narrative format.

RESULTS

There is a hidden epidemic of cognitive dysfunction in the perioperative setting. Up to 40% of patients who develop postoperative delirium (POD) never return to their preoperative cognitive baseline. POD can lead to postoperative cognitive dysfunction (POCD), a more prolonged cognitive impairment associated with longer length of hospital stay and cost, premature withdrawal from the workforce, and greater 1-year mortality. Standardized perioperative cognitive assessment is needed to enable progress. Improving outcomes will depend on a multifaceted approach, including correction of modifiable preoperative risk factors and prompt treatment of POD. Risk factors are discussed and possible interventional strategies are presented.

CONCLUSION

Closer preoperative collaboration between surgeons, geriatricians, and anesthetists will enable identification of complex at-risk older patients. A paradigm shift in the approach to management of the older surgical patient is critical to improve postoperative cognitive outcomes in modern surgery.

Surgery and Anesthesia Exposure Is Not a Risk Factor for Cognitive Impairment After Major Noncardiac Surgery and Critical Illness

OBJECTIVE

The aim of this study was to determine whether surgery and anesthesia exposure is an independent risk factor for cognitive impairment after major noncardiac surgery associated with critical illness.

SUMMARY OF BACKGROUND DATA

Postoperative cognitive impairment is a prevalent individual and public health problem. Data are inconclusive as to whether this impairment is attributable to surgery and anesthesia exposure versus patients' baseline factors and hospital course.

METHODS

In a multicenter prospective cohort study, we enrolled ICU patients with major noncardiac surgery during hospital admission and with nonsurgical medical illness. At 3 and 12 months, we assessed survivors' global cognitive function with the Repeatable Battery for the Assessment of Neuropsychological Status and executive function with the Trail Making Test, Part B. We performed multivariable linear regression to study the independent association of surgery/anesthesia exposure with cognitive outcomes, adjusting initially for baseline covariates and subsequently for in-hospital covariates.

RESULTS

We enrolled 1040 patients, 402 (39%) with surgery/anesthesia exposure. Median global cognition scores were similar in patients with surgery/anesthesia exposure compared with those without exposure at 3 months (79 vs 80) and 12 months (82 vs 82). Median executive function scores were also similar at 3 months (41 vs 40) and 12 months (43 vs 42). Surgery/anesthesia exposure was not associated with worse global cognition or executive function at 3 or 12 months in models incorporating baseline or in-hospital covariates (P > 0.2). Higher baseline education level was associated with better global cognition at 3 and 12 months (P < 0.001), and longer in-hospital delirium duration was associated with worse global cognition (P < 0.02) and executive function (P < 0.01) at 3 and 12 months.

CONCLUSIONS

Cognitive impairment after major noncardiac surgery and critical illness is not associated with the surgery and anesthesia exposure but is predicted by baseline education level and in-hospital delirium.

Lasting impact of general anaesthesia on the brain: mechanisms and relevance

General anaesthesia is usually considered to safely induce a reversible brain state allowing the performance of surgery under optimal conditions. An increasing number of clinical and experimental observations, however, suggest that anaesthetic drugs, especially when they are administered at the extremes of age, can trigger long-term morphological and functional alterations in the brain. Here, we review available mechanistic data linking general-anaesthesia exposure to impaired cognitive performance in both young and mature nervous systems. We also provide a critical appraisal of the translational value of animal models and highlight the important challenges that need to be addressed to strengthen the link between laboratory work and clinical investigations in the field of anaesthesia-neurotoxicity research.

Edaravone improves spatial memory and modulates endoplasmic reticulum stress-mediated apoptosis after abdominal surgery in mice

Patients who receive major surgery often develop postoperative cognitive dysfunction (POCD); however, there is a lack of effective management as the pathogenesis of this disorder has not been fully elucidated. The neuroprotective effects of edaravone have been characterized in both in vitro cultured cells and in experimental animal models. The present study aimed to determine the potential role of edaravone in surgery-induced cognitive decline in mice. Animals were assigned to three groups: Control group (n=32), where mice received local anesthesia; surgery group (n=32), where mice underwent abdominal surgery under anesthesia; and edaravone group (n=32), where mice received abdominal surgery and were administered with edaravone (3 mg/kg). Morris water maze and T-maze tests demonstrated that edaravone attenuated surgery-induced cognitive impairment. Nissl staining indicated that edaravone prevented neuronal loss in the hippocampus of mice that underwent surgery. Furthermore, treatment with edaravone mitigated the surgery-induced upregulation of glucose-regulated protein 78 and CCAAT-enhancer-binding homologous protein and reduced the number of terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling-positive nuclei in mice hippocampi. In conclusion, edaravone may prevent POCD-induced neuronal apoptosis through attenuating endoplasmic reticulum stress.

Multimodal analgesia and regional anaesthesia

Multimodal analgesia provides quality analgesia, with fewer side effects due to the use of combined analgesics or analgesic techniques. Regional anaesthesia plays a fundamental role in achieving this goal. The different techniques of regional anaesthesia that include both peripheral and central blocks in either a single dose or in continuous infusion help to modulate the nociceptive stimuli that access the central level. The emergence of the ultrasound as an effective system to perform regional anaesthesia techniques has allowed the development of new regional anaesthesia techniques that formerly could not be carried out since only neurostimulation or skin references were used. It is essential to take into account that even with effective blocking it is advisable to associate other drugs by other routes, in this way we will be able to reduce the required doses individually and attempt to achieve a synergistic, not purely additive, effect.

Role of β2-microglobulin in postoperative cognitive decline

Aim: β2-microglobulin (β2M) was proved to affect hippocampal functions in mice. Materials & methods: Seventy-one patients undergoing aortic valve replacement were analyzed in prospective observational study. Kidney biomarkers and Mini Mental State Examinations (MMSEs) were performed before procedure, at discharge and after 6 months. Results: Patients with β2M increase over the median change (>0.42 mg/l) experienced a significant in-hospital drop in MMSE (p = 0.005). Patients with β2M increase over the median change also failed to improve a delayed-word-recall domain of the test (p = 0.826) while patients with a lower increase improved results in the domain (p = 0.004). After 6 months, MMSE improvement was associated with a significant decrease in β2M (p = 0.042). Conclusion: These are the first in man data demonstrating relation between changes in cognition and β2M. The phenomenon was reversible which indicates its therapeutic potential.

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

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

Neurologic Complications in Noncardiac Surgery

In this article, the incidence of nervous system injuries associated with noncardiac surgery is reviewed briefly. In general, these can be divided into injuries that are clinically apparent (eg, stroke or peripheral nerve damage), which may generally be detectable on clinical examination, and more subtle forms of brain injury (eg, personality changes and postoperative cognitive dysfunction), injuries that are primarily detected by neuropsychological testing.

Postoperative cognitive changes after total knee arthroplasty under regional anesthesia

BACKGROUND

The type of postoperative cognitive decline after surgery under spinal anesthesia is unknown. We investigated the type of postoperative cognitive decline after total knee arthroplasty (TKA). Neuropsychological testing was conducted and the changes in cerebrospinal fluid (CSF) biomarkers after surgery were evaluated.

METHODS

Fifteen patients who required bilateral TKA at a 1-week interval under spinal anesthesia were included. Neuropsychological tests were performed twice, once the day before the first operation and just before the second operation (usually 1 week after the first test) to determine cognitive decline. Validated neuropsychological tests were used to examine 4 types of cognitive decline: memory, frontal-executive, language-semantic, and others. Concentrations of CSF amyloid peptide, tau protein, and S100B were measured twice during spinal anesthesia at a 1-week interval. The patients showed poor performance in frontal-executive function (forward digit span, semantic fluency, letter-phonemic fluency, and Stroop color reading) at the second compared to the first neuropsychological assessment.

RESULTS

S100B concentration decreased significantly 1 week after the operation compared to the basal value (638 ± 178 vs 509 ± 167 pg/mL) (P = 0.019). Amyloid protein β1-42, total tau, and phosphorylated tau concentrations tended to decrease but the changes were not significant.

CONCLUSION

Our results suggest that frontal-executive function declined 1 week after TKA under spinal anesthesia. The CSF biomarker analysis indicated that TKA under regional anesthesia might not cause neuronal damage.

Voluntary exercise rescues sevoflurane-induced memory impairment in aged male mice

Postoperative cognitive impairment is especially common in older patients following major surgery. Although exposure to sevoflurane is known to cause memory deficits, few studies have examined the putative approaches to reduce such impairments. This study tested the hypotheses that sevoflurane exposure can decrease NR2B subunit-containing NMDA receptor activity in hippocampus of aged mice, and voluntary exercise may counteract the declining hippocampal functions. We found that long exposure (3 h/day for 3 days), but not short exposure (1 h/day for 3 days), to 3 % sevoflurane produced a long-lasting spatial memory deficits up to 3 weeks in aged mice, and such an effect was not due to the neuronal loss in the hippocampus, but was correlated with a long-term decrease in Fyn kinase expression and NR2B subunit phosphorylation in the hippocampus. Furthermore, voluntary exercise rescued sevoflurane-induced spatial memory deficits in aged mice and restored Fyn kinase expression and NR2B subunit phosphorylation in the hippocampus to a level comparable to control animals. Generally, our results suggested that Fyn-mediated NR2B subunit phosphorylation may play a critical role in sevoflurane-induced impairment in cognitive functions in aged animals, and voluntary exercise might be an important non-pharmacological approach to treatment of inhaled anesthetics-induced postoperative cognitive impairment in clinical settings.

Pathological changes of the hippocampus and cognitive dysfunction following frontal lobe surgery in a rat model

BACKGROUND

Postoperative cognitive dysfunction (POCD) is a known complication after intracranial surgery. Impaired hippocampal neurogenesis has been associated with cognitive dysfunction in animal models.

METHODS

In order to assess hippocampal changes after brain surgery, a frontal lobe corticectomy was performed in ten adult Wistar rats (group 4). Three different control groups (n = 10 each) included no treatment (G1), general anesthesia alone (G2), and craniectomy without dural opening (G3). Twenty-four hours after surgery, half of the animals were killed, and the mRNA levels for IL-6, TNF-α, and brain-derived growth factor (BDNF) in the contralateral hippocampus were assessed by qPCR. Seven days later, the remaining animals underwent anxiety and memory testing. Afterwards, the number of immature neurons in the hippocampal cortex was measured by doublecortin (DCX) staining.

RESULTS

Twenty-four hours after surgery, mRNA levels of IL-6 and TNF-α increased and BDNF decreased in both surgical groups G3 and G4 (p = 0.012). Cognitive tests demonstrated an increase in anxiety levels and memory impairment in surgical groups compared with non-surgical animals. These changes correlated with an inhibition of hippocampal neurogenesis evidenced by a decreased number of new neurons (mean ± SD for G1-4: 66.4 ± 24; 57.6 ± 22.2; 21.3 ± 3.78; 5.7 ± 1.05, p < 0.001, non-parametric ANOVA).

CONCLUSIONS

Intracranial surgery was demonstrated to induce an inflammatory reaction within the hippocampus that compromised neurogenesis and impaired normal cognitive processing. Corticectomy had a greater effect than craniotomy alone, indicating a central trigger for hippocampal inflammatory changes. POCD after craniotomy may originate from a central inflammatory response resulting from surgical trauma to the brain parenchyma.

No convincing association between post-operative delirium and post-operative cognitive dysfunction: a secondary analysis

BACKGROUND

Post-operative delirium and post-operative cognitive dysfunction (POCD) are both common but it has not been clarified how closely they are associated. We aimed to assess the possible relationship in a secondary analysis of data from the 'Surgery Depth of anaesthesia and Cognitive outcome'- study.

METHODS

We included patients aged ≥ 60 years undergoing non-cardiac surgery planned for longer than 60 min. Delirium was assessed according to the Diagnostic and Statistical Manual of Mental Disorders IV criteria in the post-anaesthesia care unit (PACU) as well as within the first week after surgery. Cognitive function was assessed with a neuropsychological test battery. Multivariable analysis of POCD was performed with consideration of predisposing and precipitating factors.

RESULTS

Of 1277 randomized patients, 850 (66.6%) had complete data. Delirium was found in 270 patients (32.9% of 850). We detected POCD in 162 (20.9% of 776) at 1 week and in 52 (9.4% of 553) at 3 months. In multivariable analysis (n = 808), delirium had no overall effect on POCD (P = 0.30). Patients with no delirium in PACU but with postoperative delirium within 7 days had an increased risk of POCD at 3 months (OR = 2.56 (95%-confidence interval: 1.07-6.16), P = 0.035). No significant association was found for the other subgroups.

CONCLUSIONS

There is no clear evidence that postoperative delirium is independently associated with POCD up to 3 months.

Influence of General Anesthesia on Impulsivity and Learning Ability-Experimental Study

Objective: To investigate the effect of anesthesia on rats’ ability of learning and over their impulsivity.

Material and Methods: We studied eight Wistar adult male rats, test and drug naive subjects. Animals were separated in two groups, group A and B with four members each. Group A included the anesthetized animals. The combination of ketamine, xylazine and piplophen in 2ml/kg body weight dosage was used and testing was done 24 hours after anesthesia. Group B was taken as control. The study was conducted using the ”Delay discounting” apparatus. Experiments assessing impulsive behavior were conducted using automated operant chambers, equipped with two nose-poke holes (holes where pellets of food were released). Rat’s answer was considered touching the nose-poke hole. One answer was rewarded with pellets of food of 45 mg each (small reward), while another hole released five pellets of 45 mg each (high reward). Both types of rewards were presented immediately after rat’s answer and were followed for a period of 25 seconds timeout. During the training phase, rats were placed in operant chambers 30 minutes per day, 5 consecutive days. The growing percent of preference for greater reward indicates learning. For the testing phase the procedure was similar, but a delay was introduced before the release of the big reward. During this phase, the preference for higher reward was indicative for non-impulsive behaviour.

Results: The results didn’t show significant statistically differences between the two groups.

Conclusions: Anesthesia had no effect on learning ability nor on impulsivity.

Perioperative regional anaesthesia and postoperative longer-term outcomes

Regional anaesthesia provides effective anaesthesia and analgesia in the perioperative setting. Central neuraxial blocks-that is, spinal and epidural blocks-are well established as an alternative or adjunct to general anaesthesia. Peripheral blocks may be used as part of multimodal anaesthesia/analgesia in perioperative practice, reducing the need for opioid analgesics and enhancing early recovery. Furthermore, regional anaesthesia has increased in popularity and may be done with improved ease and safety with the introduction of ultrasound-guided techniques. The effects of local anaesthetics and regional anaesthesia on long-term outcomes such as morbidity, mortality, the quality of recovery beyond the duration of analgesia, and whether it can expedite the resumption of activities of daily living are less clear. It has also been suggested that regional anaesthesia may impact the risk of metastasis after cancer surgery. This article provides an overview of current evidence around quality of recovery, risk for delirium, long-term effects, and possible impact on cancer disease progression associated with the clinical use of local and regional anaesthetic techniques. In summary, there is still a lack of robust data that regional anaesthesia has a clinical impact beyond its well-acknowledged beneficial effects of reducing pain, reduced opioid consumption, and improved quality of early recovery. Further high-quality prospective studies on long-term outcomes are warranted.

Orthopedic Surgery and Post-Operative Cognitive Decline in Idiopathic Parkinson's Disease: Considerations from a Pilot Study

BACKGROUND

Post-operative cognitive dysfunction (POCD) demarks cognitive decline after major surgery but has been studied to date in "healthy" adults. Although individuals with neurodegenerative disorders such as Parkinson's disease (PD) commonly undergo elective surgery, these individuals have yet to be prospectively followed despite hypotheses of increased POCD risk.

OBJECTIVE

To conduct a pilot study examining cognitive change pre-post elective orthopedic surgery for PD relative to surgery and non-surgery peers.

METHODS

A prospective one-year longitudinal design. No-dementia idiopathic PD individuals were actively recruited along with non-PD "healthy" controls (HC) undergoing knee replacement surgery. Non-surgical PD and HC controls were also recruited. Attention/processing speed, inhibitory function, memory recall, animal (semantic) fluency, and motor speed were assessed at baseline (pre-surgery), 3 weeks, 3 months, and 1 year post- orthopedic surgery. Reliable change methods examined individual changes for PD individuals relative to control surgery and control non-surgery peers.

RESULTS

Over two years we screened 152 older adult surgery or non-surgery candidates with 19 of these individuals having a diagnosis of PD. Final participants included 8 PD (5 surgery, 3 non-surgery), 47 Control Surgery, and 21 Control Non-Surgery. Eighty percent (4 of the 5) PD surgery declined greater than 1.645 standard deviations from their baseline performance on measures assessing processing speed and inhibitory function. This was not observed for the non-surgery PD individuals.

CONCLUSION

This prospective pilot study demonstrated rationale and feasibility for examining cognitive decline in at-risk neurodegenerative populations. We discuss recruitment and design challenges for examining post-operative cognitive decline in neurodegenerative samples.

Deferoxamine pre-treatment protects against postoperative cognitive dysfunction of aged rats by depressing microglial activation via ameliorating iron accumulation in hippocampus

Postoperative cognitive dysfunction (POCD) is a common complication of elderly patients after surgery. The mechanisms of POCD have not been clarified. Iron accumulation is a feature of neurodegeneration. Recent reports showed that iron content was increased with impaired cognition induced by surgery. We sought to investigate whether iron chelation would attenuate POCD. In this study, male aged (18 months) Sprague-Dawley rats received 100 mg/kg deferoxamine or saline solution (0.9%) for 6 days before exploratory laparotomy. Cognition was evaluated by Morris water maze before and after surgery. Additional rats received deferoxamine or saline were used to determine hippocampal iron content, iron transport-related proteins (transferrin receptor, divalent metal transporter 1, ferroportin 1 and hepcidin), oxidative stress, microglial activation and brain cell apoptosis. It was found that deferoxamine improved postoperative spatial memory in aged rats. Deferoxamine significantly reduced hippocampal iron concentration and ferritin. Surgery increased divalent metal transporter 1 and hepcidin, decreased transferrin receptor and ferroportin 1, and enhanced ferroportin 1 mRNA. However, deferoxamine reversed the changes of these proteins. Furthermore, deferoxamine sharply reduced the hippocampal reactive oxygen species, malondialdehyde concentration and OX-42 that is a marker of microglia, which might reduce postoperative brain cell apoptosis. This study showed that deferoxamine may improve postoperative cognition of aged rats by ameliorating oxidative stress induced by hippocampal iron accumulation, microglial activation and brain cell apoptosis. This study suggests a potential therapeutic method for reducing POCD.

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.

Comparison of the type and severity of early attentional network decline after total intravenous or epidural anesthesia in middle-aged women after gynecological surgery

Compared with regional anesthesia, general anesthesia may increase the risk of postoperative cognitive decline. This study aimed to investigate the type and severity of attentional network decline and the recovery of attentional networks in middle-aged women after gynecological surgery. A total of 140 consenting women undergoing elective gynecological surgery were enrolled in the study. Patients were assigned randomly to receive either total intravenous anesthesia or epidural anesthesia. To determine the efficacy of the attentional networks, patients were examined for alerting, orienting, and executive networks on the preoperative day and on the first and fifth postoperative days using the attentional network test. Significant differences were observed in the effect scores of the three attentional networks at all time points. These effect scores differed significantly between groups and between 1 and 5 days postoperation (DPO). Participants showed significantly lower effect scores for the alerting and orienting network tasks and had more difficulties in resolving conflict at 1 DPO compared with the baseline. On comparing effect scores between baseline and 5 DPO, no significant differences on the alerting and orienting network tasks were observed in the epidural anesthesia group, a significant difference on the orienting network task was observed in the general anesthesia group, and significant differences on the executive control network were observed in both the groups. Compared with epidural anesthesia, total intravenous anesthesia is more likely to impair and delay the recovery of attentional networks in middle-aged women undergoing elective hysterectomy. The executive control function showed marked damage and there were difficulties in recovery from either type of anesthesia.

Influence of different anesthetic and analgesic methods on early cognitive function of elderly patients receiving non-cardiac surgery

Objective:

To discuss over influence of two different anesthetic and analgesic methods on early cognitive function of elderly patients who received non-cardiac surgery.

Methods:

Two hundred and six elderly patients who underwent non-cardiac surgery were selected as research subjects. They were randomly divided into observation group (103 cases) and control group (103 cases). Patients in observation group were given combined spinal and epidural anesthesia and epidural analgesia, while patients in control group adopted general anesthesia and intravenous analgesia. Neurological function test was carried out one day before surgery and on the 7^th day after surgery. Moreover, changes of postoperative pain degree, neuropsychological function and cognitive function were observed and compared.

Results:

On the 7^th day after surgery, incidence of cognition impairment in observation group and control group was 48.50% (50/103 cases) and 44.70% (46/103 cases), and difference between groups had no statistical significance. Visual Analogue Scale (VAS) Score of observation group was much lower than control group in the 12^th, 24^th and 48^th h after surgery (p < 0.05). Logistic regression analysis suggested that, short education years and general surgery were independent risk factors for early cognition impairment.

Conclusion:

About 46.60% elderly patients undergoing non-cardiac surgery developed cognition impairment, but influence of different anesthetic and analgesic methods on incidence of postoperative cognition impairment of elderly patients had no significant difference.

Original Research: Establishment of an early embolus-related cerebral injury model after cardiopulmonary bypass in miniature pigs

Embolus-related cerebral injury is still a serious adverse event after cardiopulmonary bypass (CPB). But there is no stable animal model for basic and clinical research purposes. We chose miniature pig to establish a stable animal model of embolus-related cerebral injury after CPB and verified the validity of results by correlating the histopathological findings with those of diffusion-weighted magnetic resonance imaging (DW-MRI). Based on different treatment regimens, 24 male miniature pigs were randomly assigned into four groups: Control, CPB, embolus, and CPB-embolus groups. DW-MRI was performed before and after surgery to diagnose and locate the brain lesions. Histopathological changes in brain tissues were examined using H&E and Nissl staining. All surgical procedures were uneventful with 100% postoperative survival of pigs. Two animals in the Embolus group and six animals in the CPB-embolus group showed signs of ischemic penumbra on DW-MRI performed 6 h after surgery. Consistent with the results of DW-MRI, histopathological examination showed necrosis and ischemic lesions. In this paper, we demonstrate the feasibility and validity of a pig model of embolus-related cerebral injury associated with CPB. This model may be used in the future for basic and translational research.

Impact of Controlled Induced Hypotension on Cognitive Functions of Patients Undergoing Functional Endoscopic Sinus Surgery

Background

Controlled induced hypotension guarantees less blood loss and better visibility of the surgical site. The impact of hypotension on post-operative cognitive functions is still being discussed. The objective of this study was to evaluate the effects of controlled induced hypotension on the cognitive functions of patients undergoing functional endoscopic sinus surgery (FESS).

Material/Methods

We allocated 47 patients with a good grade of preoperative cognitive functions evaluated with the Mini-Mental State Examination to 3 groups (1 – mild hypotension, 2 – intermediate hypotension, 3 – severe hypotension) according to the degree of mean intraoperative arterial pressure compared with preoperative blood pressure. Cognitive functions were evaluated preoperatively, 6 h, and 30 h postoperatively with standardized tests: the Stroop Test, Trail Making Test (TMT), and Verbal Fluency Test (VFT). A decrease in the test results and increase in the number of mistakes made were considered an impairment of cognitive functions.

Results

A total of 47 patients (group 1 – mild hypotension – 15, group 2 – intermediate hypotension – 19, group 3 – severe hypotension – 13) were included in the study. A significant decrease was observed in all the 3 groups after Stroop A test 6h postoperatively but it improved 30h postoperatively, without differences between the groups. Neither a significant decrease in the test results nor an increase in the number of mistakes was noted for Stroop B tests, TMT A&B tests and VFT.

Conclusions

The degree of controlled intraoperative hypotension during FESS did not influence the results of psychometric tests.

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.

Changes in cerebral oxygen saturation and early postoperative cognitive function after laparoscopic gastrectomy: a comparison with conventional open surgery

BACKGROUND

Laparoscopic gastrectomy requires a reverse-Trendelenburg position and prolonged pneumoperitoneum and it could cause significant changes in cerebral homeostasis and lead to cognitive dysfunction. We compared changes in regional cerebral oxygen saturation (rSO2), early postoperative cognitive function and hemodynamic variables in patients undergoing laparoscopic gastrectomy with those patients that underwent conventional open gastrectomy.

METHODS

Sixty patients were enrolled in this study and the patients were distributed to receive either laparoscopic gastrectomy (laparoscopy group, n = 30) or open conventional gastrectomy (open group, n = 30). rSO2, end-tidal carbon dioxide tension, hemodynamic variables and arterial blood gas analysis were monitored during the operation. The enrolled patients underwent the mini-mental state examination 1 day before and 5 days after surgery for evaluation of early postoperative cognitive function.

RESULTS

Compared to baseline value, rSO2 and end-tidal carbon dioxide tension increased significantly in the laparoscopy group after pneumoperitoneum, whereas no change was observed in the open group. No patient experienced cerebral oxygen desaturation or postoperative cognitive dysfunction. Changes in mean arterial pressure over time were significantly different between the groups (P < 0.001).

CONCLUSIONS

Both laparoscopic and open gastrectomy did not induce cerebral desaturation or early postoperative cognitive dysfunction in patients under desflurane anesthesia. However, rSO2 values during surgery favoured laparoscopic surgery, which was possibly related to increased cerebral blood flow due to increased carbon dioxide tension and the effect of a reverse Trendelenburg position.

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.

Neuroprotective Effects Against POCD by Photobiomodulation: Evidence from Assembly/Disassembly of the Cytoskeleton

Postoperative cognitive dysfunction (POCD) is a decline in memory following anaesthesia and surgery in elderly patients. While often reversible, it consumes medical resources, compromises patient well-being, and possibly accelerates progression into Alzheimer's disease. Anesthetics have been implicated in POCD, as has neuroinflammation, as indicated by cytokine inflammatory markers. Photobiomodulation (PBM) is an effective treatment for a number of conditions, including inflammation. PBM also has a direct effect on microtubule disassembly in neurons with the formation of small, reversible varicosities, which cause neural blockade and alleviation of pain symptoms. This mimics endogenously formed varicosities that are neuroprotective against damage, toxins, and the formation of larger, destructive varicosities and focal swellings. It is proposed that PBM may be effective as a preconditioning treatment against POCD; similar to the PBM treatment, protective and abscopal effects that have been demonstrated in experimental models of macular degeneration, neurological, and cardiac conditions.

Regional versus general anaesthesia for improved cognitive function after procedures other than cardiac surgery or neurosurgery in adult and paediatric patients

This is the protocol for a review and there is no abstract. The objectives are as follows: The objective of this review is to compare the effects of regional versus general anaesthesia on cognitive function after procedures other than cardiac surgery or neurosurgery in adult and in paediatric patients.

Effects of anesthesia type on short-term postoperative cognitive function in obstetric patients following cesarean section

OBJECTIVE

We aimed to compare the effects of general and spinal anesthesia on cognitive functions in pregnant patients undergoing elective cesarean section.

MATERIAL AND METHODS

Seventy-five American Society of Anesthesiology (ASA) I pregnant patients aged 18-40 years who were scheduled to undergo elective cesarean section were divided into three groups. Group sevoflurane (Group S) and Group desflurane (Group D) were administered general anesthesia, whereas Group regional (Group R) was administered spinal anesthesia. Hemodynamic variables, bispectral index, oxygen saturation were measured at baseline, after induction, spinal injection, and during the surgery. Extubation and eye opening time and Aldrete scores were recorded. Mini-mental state examination, Trieger dot test, and clock drawing test were performed one day before the surgery and repeated at the 1(st), 3(rd) and 24(th) h postoperatively.

RESULTS

There was no statistically significant difference among the groups in terms of demographic data and duration of surgery (p>0.05). Durations of anesthesia for Group S, Group R, and Group D were significantly different (p<0.05). Duration of anesthesia for Group R was significantly longer than for Groups S and D (p<0.0001). Aldrete recovery scores and total remifentanil consumption were significantly higher in Group D than in Group S (p<0.05). Extubation and eye opening times were significantly shorter in Group D than in Group S (p<0.01). According to TDT, statistical significance was found among Group S, Group R, and Group D at the 3rd and 24th h postoperatively (p<0.05), and there was a statistically high significant difference in Groups S and R (p<0.0001).

CONCLUSION

We concluded that general anesthesia with sevoflurane or desflurane and spinal anesthesia had no effects on cognitive functions in patients undergoing cesarean operation.

Enhanced Recovery After Surgery (ERAS) for gastrointestinal surgery, part 1: pathophysiological considerations

BACKGROUND

The present article has been written to convey concepts of anaesthetic care within the context of an Enhanced Recovery After Surgery (ERAS) programme, thus aligning the practice of anaesthesia with the care delivered by the surgical team before, during and after surgery.

METHODS

The physiological principles supporting the implementation of the ERAS programmes in patients undergoing major abdominal procedures are reviewed using an updated literature search and discussed by a multidisciplinary group composed of anaesthesiologists and surgeons with the aim to improve perioperative care.

RESULTS

The pathophysiology of some key perioperative elements disturbing the homoeostatic mechanisms such as insulin resistance, ileus and pain is here discussed.

CONCLUSIONS

Evidence-based strategies aimed at controlling the disruption of homoeostasis need to be evaluated in the context of ERAS programmes. Anaesthesiologists could, therefore, play a crucial role in facilitating the recovery process.

Interleukin17A Promotes Postoperative Cognitive Dysfunction by Triggering β-Amyloid Accumulation via the Transforming Growth Factor-β (TGFβ)/Smad Signaling Pathway

Although postoperative cognitive dysfunction (POCD) is relatively common in elderly patients who have undergone major surgery, the mechanisms underlying this postoperative complication are unclear. Previously, we have investigated the role of cytokine-mediated hippocampal inflammation in the development of POCD in a rat model. Here, we sought to determine in mice the role of cytokine interleukin17A (IL17A) in POCD and to characterize the associated signaling pathways. Old mice underwent hepatectomy surgery in the presence or absence of IL17A monoclonal antibody, and cognitive function, hippocampal neuroinflammation, and pathologic markers of Alzheimer’s disease (AD) were assessed. We found that the level of IL17A in the hippocampus was increased in hepatectomy mice and that cognitive impairment after surgery was associated with the appearance of certain pathological hallmarks of AD: activation of astrocytes, β-amyloid_1-42 (Aβ_1–42) production, upregulation of transforming growth factor-β (TGFβ), and increased phosphorylation of signaling mother against decapentaplegic peptide 3 (Smad3) protein in the hippocampus. Surgery-induced changes in cognitive dysfunction and changes in Aβ_1–42 and TGFβ/Smad signaling were prevented by the administration of IL17A monoclonal antibody. In addition, IL17A-stimulated TGFβ/Smad activation and Aβ_1–42 expression were reversed by IL17A receptor small interfering RNA and a TGFβ receptor inhibitor in cultured astrocytes. Our findings suggest that surgery can provoke IL17A-related hippocampal damage, as characterized by activation of astrocytes and TGFβ/Smad pathway dependent Aβ_1–42 accumulation in old subjects. These changes likely contribute to the cognitive decline seen in POCD.

Totally extraperitoneal (TEP) endoscopic hernia repair in elderly patients

BACKGROUND

Inguinal hernias are common in elderly males. We addressed outcome following totally extraperitoneal (TEP) hernia repair in patients older than 70 years.

METHODS

We prospectively collected data of patients >70 years with a unilateral or bilateral inguinal hernia operated in our hospital between January 2005 and January 2010 using the TEP technique.

RESULTS

A total of 429 patients underwent TEP hernia repair under general anaesthesia, mostly men (n = 405; 94.4%). Median age was 74 years (range 70-89). The mean pre-operative pain score was 3.7 (SD ± 2.5). Ninety-four percent of patients had an ASA score of 1 or 2. Three hundred thirty-six patients underwent a unilateral repair (78%). The conversion rate to an anterior procedure was 0.7 % (n = 3). In 8 patients (1.9%), intra-operative complications occurred, and the postoperative course was complicated in 3 patients (0.7 %). Severe complications attributable to the endoscopic approach occurred in 6 patients (1.4%): a bladder injury (n = 5) and a trocar-induced bowel perforation (n = 1). The mean postoperative pain score after 6 weeks was 1.6 (SD ± 1.2). Patients were able to resume their daily activities after a median of 7 days (range 1-42).

CONCLUSION

Totally, extraperitoneal endoscopic inguinal hernia repair in elderly patients is associated with low overall complication rates and a fast recovery. In a small proportion of patients, severe complications occur attributable to the endoscopic approach.

General versus spinal anaesthesia and postoperative delirium in an orthogeriatric population

AIM

Postoperative delirium is common among elderly hip surgery patients. We aimed to pragmatically evaluate whether type of anaesthesia influenced postoperative delirium in an orthogeriatric population following hip fracture.

METHOD

This observational study comprises prospectively collected data on hip fracture patients admitted between October 2010 and November 2011. Delirium was diagnosed clinically by geriatricians.

RESULTS

Of the 344 patients admitted, seven managed conservatively and 19 with incomplete data were excluded; 318 patients were analysed. Average age was 81.6 (SD 9.8) years; 28% were men and 167 (53%) were administered general anaesthesia. Mean length of stay was 18 (SD 9.4) days. Overall, 172 patients (54%) experienced delirium. There was no apparent difference in postoperative delirium by anaesthetic type (88 vs 84, P = 0.15).

CONCLUSION

Delirium was common in both general and spinal anaesthetic patients. Further randomised controlled trials would be required to determine whether anaesthesia type influenced delirium rates.