Peri- and postoperative cognitive and consecutive functional problems of elderly patients

Intravenous infusion of dexmedetomidine during the surgery to prevent postoperative delirium and postoperative cognitive dysfunction undergoing non-cardiac surgery: a meta-analysis of randomized controlled trials

BACKGROUND

Dexmedetomidine plays a pivotal role in mitigating postoperative delirium and cognitive dysfunction while enhancing the overall quality of life among surgical patients. Nevertheless, the influence of dexmedetomidine on such complications in various anaesthesia techniques remains inadequately explored. As such, in the present study, a meta-analysis was conducted to comprehensively evaluate its effects on postoperative delirium and cognitive dysfunction.

METHODS

A number of databases were searched for randomised controlled trials comparing intravenous dexmedetomidine to other interventions in preventing postoperative delirium and cognitive dysfunction in non-cardiac and non-neurosurgical patients. These databases included PubMed, Embase, and Cochrane Library. Statistical analysis and graphing were performed using Review Manager, STATA, the second version of the Cochrane risk-of-bias tool for randomised controlled trials, and GRADE profiler.

MAIN RESULTS

This meta-analysis comprised a total of 24 randomised controlled trials, including 20 trials assessing postoperative delirium and 6 trials assessing postoperative cognitive dysfunction. Across these 24 studies, a statistically significant positive association was observed between intravenous administration of dexmedetomidine and a reduced incidence of postoperative delirium (RR: 0.55; 95% CI 0.47 to 0.64, p < 0.00001, I2 = 2%) and postoperative cognitive dysfunction (RR: 0.60; 95% CI 0.38 to 0.96, p = 0.03, I2 = 60%). Subgroup analysis did not reveal a significant difference in the incidence of postoperative delirium between the general anaesthesia and non-general anaesthesia groups, but a significant difference was observed in the incidence of postoperative cognitive dysfunction. Nonetheless, when the data were pooled, it was evident that the utilisation of dexmedetomidine was associated with an increased incidence of hypotension (RR: 1.42; 95% CI 1.08 to 1.86, p = 0.01, I2 = 0%) and bradycardia (RR: 1.66; 95% CI 1.23 to 2.26, p = 0.001, I2 = 0%) compared with other interventions. However, there was no significantly higher occurrence of hypertension in the DEX groups (RR = 1.35, 95% CI 0.81-2.24, p = 0.25, I2 = 0%).

CONCLUSION

Compared with other interventions, intravenous dexmedetomidine infusion during non-cardiac and non-neurosurgical procedures may significantly reduce the risk of postoperative delirium and cognitive dysfunction. The results of subgroup analysis reveal a consistent preventive effect on postoperative delirium in both general and non-general anaesthesia groups. Meanwhile, continuous infusion during general anaesthesia was more effective in reducing the risk of cognitive dysfunction. Despite such findings, hypotension and bradycardia were more frequent in patients who received dexmedetomidine during surgery.

Effect of remote ischemic preconditioning on postoperative cognitive dysfunction in adult patients with general anesthesia: a meta-analysis

BACKGROUND

Remote ischemic preconditioning (RIPC) is proven to have neuroprotective protective effects. Nevertheless, the impact of RIPC on postoperative cognitive dysfunction (POCD) in patients undergoing general anesthesia is controversial. This meta-analysis of randomized controlled trials (RCTs) aimed to assess the effect of RIPC on POCD in adults after general anesthesia.

METHODS

Relevant literature was obtained by searching Embase, PubMed, Web of Science, Cochrane Library, Wanfang, and China National Knowledge Infrastructure (CNKI) databases in July 2022. RCTs were included to assess the influences of RIPC on POCD in adults following general anesthesia. Two investigators independently performed literature screening, data extraction, and quality assessment based on the inclusion and exclusion criteria. The incidence of POCD, operation time, and hospital stay were analyzed by Review manager5.4 software.

RESULTS

Thirteen RCTs with 1122 participants were selected for this meta-analysis. Compared to the control group, RIPC decreased the incidence of POCD (OR = 0.50, 95% CI 0.31-0.82), as well as reduced the duration of hospitalization (MD = - 0.98, 95% CI - 1.69 to - 0.27), but did not prolong operative time (MD = - 2.65, 95% CI - 7.68 to 2.37).

CONCLUSION

RIPC reduced the incidence of POCD in adult patients after general anesthesia and accelerated their discharge.

Cognitive prehabilitation for geriatric patients undergoing elective surgery: a PRISMA-P-compliant protocol for a systematic review

INTRODUCTION

The ageing of the population, as well as advances and improvements in surgery, and anaesthesia have greatly increased the demand for surgical services in geriatric patients. Neurocognitive disorders are the most common complications experienced in the postoperative period by older individuals. Improving perioperative brain health in older adults has become key actions for the multidisciplinary perioperative care teams. This comprehensive systematic review will assess the effectiveness and safety of cognitive prehabilitation programmes prior to surgery on cognitive functional capacity and postoperative cognitive outcomes in geriatric patients undergoing elective surgery.

METHODS AND ANALYSIS

This protocol was prepared using the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols. The following key electronic bibliographic databases will be searched from inception to July 2022: MEDLINE, EMBASE, CINAHL, CENTRAL, PEDro, PsycINFO, CBM, CNKI, WANFANG database and VIP. We will include randomised controlled trials published in English or Chinese that examine the effects of cognitive prehabilitation programmes on geriatric patients undergoing elective surgery. To construct the search strategy, the Patient, Intervention, Comparison, Outcome, Study scheme will be used. Two reviewers will independently complete the study screening, selection, data extraction and quality rating. The Physiotherapy Evidence Database scale will be used to assess the methodological quality of the included studies. A narrative or quantitative synthesis will be conducted based on the final data. The planned start and end dates for the study were 1 September 2021 and 1 August 2023.

ETHICS AND DISSEMINATION

Ethical approval will not be required for this protocol. The results of the final review will be disseminated via peer-reviewed journals and conference presentations.

PROSPERO REGISTRATION NUMBER

CRD42021277191.

Fluoxetine for reducing postoperative cognitive dysfunction in elderly patients after total knee replacement: study protocol for a single-centre, double-blind, randomised, parallel-group, superiority, placebo-controlled trial

INTRODUCTION

Postoperative cognitive dysfunction (POCD) is a common complication following major surgical procedures. The underlying pathophysiology is poorly understood, but the role of neuroinflammation is strongly implicated. Given the antineuroinflammatory and neuroprotective effects of fluoxetine, we hypothesise that fluoxetine may reduce the cumulative incidence of POCD in elderly patients undergoing total knee arthroplasty (TKA).

METHODS AND ANALYSIS

This is a prospective, randomised, double-blind, parallel-group, placebo-controlled, superiority trial. Five hundred elderly patients undergoing unilateral TKA will be randomly assigned to the fluoxetine and placebo groups. The fluoxetine group will receive fluoxetine 20 mg daily 8 weeks preoperatively, and the placebo group will receive placebo capsules daily 8 weeks preoperatively. The primary outcome is the cumulative incidence of POCD at 1 month postoperatively. The secondary outcomes include the occurrence of delirium, the area under the curve of the Numeric Rating Scale pain scores over time, and sleep disturbance. Data on all the results, risk factors and adverse events will also be collected and analysed.

ETHICS AND DISSEMINATION

The Fujian Provincial Hospital Ethics Board has approved the protocol for this trial (identifier number: K2021-01-009). All participants will be required to provide written informed consent before any protocol-specific procedures.

TRIAL REGISTRATION NUMBER

ChiCTR2100050424.

The effect of intraoperative dexmedetomidine on cognitive dysfunction after surgery: a updated meta-analysis

BACKGROUND

Postoperative cognitive dysfunction (POCD) is one of the most common. Neuroprotective effects of dexmedetomidine (DEX) are reported in previous studies but evidence regarding the POCD is still unclear. In order to gain latest evidence, the present study analyzes the outcomes of randomized controlled trials (RCTs) which utilized DEX with general anaesthesia perioperatively.

METHOD

Four online databases (PubMed, Embase, the Cochrane Library, and CNKI) were used to find relevant RCTs to conduct systematic analysis. All studies comparing the incidence of POCD or MMSE score between the DEX group and the placebo or comparator group in patients undergoing general anaesthetic surgery were eligible for inclusion. Based on the inclusion and exclusion criteria, the studies were selected. This meta-analysis was performed using odds ratios (ORs) with 95% confidence intervals (CIs) for dichotomous data and standardized mean difference (SMD) and 95% CIs for continuous data as effective measures.

RESULTS

In total of 21 studies were included in this meta-analysis. The results showed that the incidence of POCD in DEX group was significantly lower than the control group on the first (OR = 0.36, 95% CI 0.24-0.54),third (OR = 0.45,95% CI 0.33-0.61) and seventh (OR = 0.40,95% CI 0.26-0.60) postoperative days; the MMSE scores in DEX group were higher than the control group on the first (SMD = 1.24, 95% CI 1.08-1.41), third(SMD = 1.09, 95%CI 0.94-1.24) and seventh (SMD = 3.28, 95% CI 1.51-5.04) postoperative days.

CONCLUSIONS

Intraoperative DEX use can ameliorate the POCD of patients who received surgical operations under general anesthesia, and effectively reduce the incidence of POCD and improve MMSE score.

Perioperative Electroencephalogram Spectral Dynamics Related to Postoperative Delirium in Older Patients

BACKGROUND

Intraoperative electroencephalography (EEG) signatures related to the development of postoperative delirium (POD) in older patients are frequently studied. However, a broad analysis of the EEG dynamics including preoperative, postinduction, intraoperative and postoperative scenarios and its correlation to POD development is still lacking. We explored the relationship between perioperative EEG spectra-derived parameters and POD development, aiming to ascertain the diagnostic utility of these parameters to detect patients developing POD.

METHODS

Patients aged ≥65 years undergoing elective surgeries that were expected to last more than 60 minutes were included in this prospective, observational single center study (Biomarker Development for Postoperative Cognitive Impairment [BioCog] study). Frontal EEGs were recorded, starting before induction of anesthesia and lasting until recovery of consciousness. EEG data were analyzed based on raw EEG files and downloaded excel data files. We performed multitaper spectral analyses of relevant EEG epochs and further used multitaper spectral estimate to calculate a corresponding spectral parameter. POD assessments were performed twice daily up to the seventh postoperative day. Our primary aim was to analyze the relation between the perioperative spectral edge frequency (SEF) and the development of POD.

RESULTS

Of the 237 included patients, 41 (17%) patients developed POD. The preoperative EEG in POD patients was associated with lower values in both SEF (POD 13.1 ± 4.6 Hz versus no postoperative delirium [NoPOD] 17.4 ± 6.9 Hz; P = .002) and corresponding γ-band power (POD -24.33 ± 2.8 dB versus NoPOD -17.9 ± 4.81 dB), as well as reduced postinduction absolute α-band power (POD -7.37 ± 4.52 dB versus NoPOD -5 ± 5.03 dB). The ratio of SEF from the preoperative to postinduction state (SEF ratio) was ~1 in POD patients, whereas NoPOD patients showed a SEF ratio >1, thus indicating a slowing of EEG with loss of unconscious. Preoperative SEF, preoperative γ-band power, and SEF ratio were independently associated with POD (P = .025; odds ratio [OR] = 0.892, 95% confidence interval [CI], 0.808-0.986; P = .029; OR = 0.568, 95% CI, 0.342-0.944; and P = .009; OR = 0.108, 95% CI, 0.021-0.568, respectively).

CONCLUSIONS

Lower preoperative SEF, absence of slowing in EEG while transitioning from preoperative state to unconscious state, and lower EEG power in relevant frequency bands in both these states are related to POD development. These findings may suggest an underlying pathophysiology and might be used as EEG-based marker for early identification of patients at risk to develop POD.

Hundred most cited articles in perioperative neurocognitive disorder: a bibliometric analysis

Background

In line with aging populations and increased application of anesthesia and surgery, perioperative neurocognitive disorder (PND) has received growing attention worldwide. Considerable researches into PND are being conducted; however, the quantity and quality of such researches have not been reported. Through a retrospective bibliometric analysis, this study aims to identify and characterize the top 100 cited publications on PND.

Methods

We searched the Web of Science database to find the top 100 cited articles focusing on PND. We collected bibliographic information, including year of publication, country of origin, article type, published journal, citation count, and authorship. To determine changes with time, we compared older and newest articles.

Results

The top 100 cited articles were published between 1955 and 2016; the number of citations ranged from 111 to 1248. The United States had the most published papers; clinical trial was the most common article type. The specialty journals of Anesthesiology and Anesthesia & Analgesia were the two most cited journals. Newest articles had a comparable number of citations to older articles, but the former had higher annual citation rates, greater funding disclosures, more focus on basic research, and more open access publications.

Conclusions

This study provides a comprehensive overview of the most cited articles and highlights the increasing attention on PND. High-quality clinical trials with a greater journal impact factor receive more citations. However, there has been a growth in the number of basic science studies as an area of research with respect to the pathogenesis of PND.

Dexmedetomidine reduces postoperative cognitive and behavioral dysfunction in adults submitted to general anesthesia for non-cardiac surgery: meta-analysis of randomized clinical trials

Introduction and objectives

Dexmedetomidine (DEX) has been associated with a decrease in postoperative cognitive and behavioral dysfunction in patients submitted to general anesthesia, whether inhalation or total intravenous anesthesia. Consequently, the DEX effects on postoperative agitation and delirium in patients submitted to general anesthesia for non-cardiac surgery have been investigated.

Method

A systematic review and meta-analysis of randomized and double-blind clinical trials (RCTs) was undertaken assessing adults submitted to elective procedures under general anesthesia receiving DEX or placebo. The search included articles published in English in the Pubmed and Web of Science databases using keywords such as dexmedetomidine, delirium, and agitation. Duplicate publications, studies involving cardiac surgery or using active control (other than saline solution) were included. A random effects model was adopted using the DerSimonian-Laird method and estimate of Odds Ratio (OR) for dichotomous variables, and weighted mean difference for continuous variables, with their respective 95% Confidence Intervals (95% CI).

Results

Of the 484 articles identified, 15 were selected comprising 2,183 patients (1,079 and 1,104 patients in the DEX and control group, respectively). The administration of DEX was considered a protective factor for postoperative cognitive and behavioral dysfunction (OR = 0.36; 95% CI 0.23–0.57 and p < 0.001), regardless of the anesthesia technique used.

Conclusion

Dexmedetomidine administration reduced by at least 43% the likelihood of postoperative cognitive and behavioral dysfunction in adult patients submitted to general anesthesia for non-cardiac surgery.

The sensitivity and specificity of statistical rules for diagnosing delayed neurocognitive recovery with Montreal cognitive assessment in elderly surgical patients: A cohort study

Delayed neurocognitive recovery (DNR) is common in elderly patients after major noncardiac surgery. This study was designed to investigate the best statistical rule in diagnosing DNR with the Montreal cognitive assessment (MoCA) in elderly surgical patients.This was a cohort study. One hundred seventy-five elderly (60 years or over) patients who were scheduled to undergo major noncardiac surgery were enrolled. A battery of neuropsychological tests and the MoCA were employed to test cognitive function at the day before and on fifth day after surgery. Fifty-three age- and education-matched nonsurgical control subjects completed cognitive assessment with the same instruments at the same time interval. The definition of the international study of postoperative cognitive dysfunction (ISPOCD 1) was adopted as the standard reference for diagnosing DNR. With the MoCA, the following rules were used to diagnose DNR: the cut-off point of ≤26; the 1 standard deviation decline from baseline; the 2 scores decline from baseline; and the Z score of ≥1.96. The sensitivity and specificity as well as the area under receiver operating characteristic curve for the above rules in diagnosis of DNR were calculated.The incidence of DNR was 13.1% (23/175) according to the ISPOCD1 definition. When compared with the standard reference, the 2 scores rule showed the best combination of sensitivity (82.6%, 95% confidence interval [CI] 67.1%-98.1%) and specificity (82.2%, 95% CI 76.2%-88.3%); it also had the largest area under receiver operating characteristic curve (0.824, 95% CI 0.728-0.921, P < .001). The cut-off point rule showed high sensitivity (95.7%) and low specificity (37.5%), whereas the 1 standard deviation and the Z score rules showed low sensitivity (47.8% and 21.7%, respectively) and high specificity (93.4% and 97.3%, respectively).Compared with the ISPOCD1 definition, the 2 scores rule with MoCA had the best combination of sensitivity and specificity to diagnose DNR.

Effect of dexmedetomidine on brain function and hemodynamics in patients undergoing lung cancer resection

Effect of dexmedetomidine on the brain function and hemodynamics in patients undergoing lung cancer resection were explored. Eighty-seven patients with lung cancer undergoing lung cancer resection in Weifang People's Hospital from January 2014 to June 2018 were enrolled in this study. Patients conventionally anesthetized by propofol, midazolam, sufentanil, or cisatracurium besilate (41 cases) were assigned to the control group and those anesthetized by conventional anesthetic and dexmedetomidine (46 cases) were assigned to the research group. The hemodynamic parameters, neuron-specific enolase (NSE), and astrocyte S-100p protein (S-100β) were compared between the two groups before induction (T0), 5 min after induction (T1), at the end of surgery (T2), time of extubation (T3), and 5 min after extubation (T4). The cognitive function of patients was graded by the mini-mental state examination (MMSE) after patients recovered from anesthesia. In both the control group and the research group, the levels of mean arterial pressure (MAP), heart rate (HR), and central venous pressure (CVP). were statistically higher at T2 and T3 than those at T0 (all P<0.05). The levels of MAP, HR, and CVP were statistically lower in the research group than those in the control group at T2 and T3 (P<0.05). The levels of serum NSE and S100β protein in the research group and the control group increased at T2, T3, and T4, the control group was higher than the research group at each time point, and the difference was statistically significant (P<0.05). Comparison of the MMSE score and the total case number of adverse reactions between the two groups showed no statistical difference (both P>0.05). The MMSE score was positively correlated with the serum levels of NSE and S100β in the two groups (r-values were 0.661 and 0.585, P<0.05). Dexmedetomidine can effectively protect patients' perioperative brain function with small impacts on perioperative hemodynamics, so it is worthy of clinical application.

Diverging Awareness of Postoperative Delirium and Cognitive Dysfunction in German Health Care Providers

Purpose

Postoperative cognitive dysfunction (POCD) appears in up to 30% of patients suffering from postoperative delirium (POD). Both are associated with higher mortality and postoperative complications, prolonged hospital stays, and increased costs. Multi-modal models with pre-admission risk reduction counselling, perioperative monitoring, and training of multidisciplinary patient care providers have been shown to decrease the prevalence of both. The aim of our study is to understand how far those measures are known and implemented in routine care and to detect potential gaps in the current practice regarding risk communication and information flow between involved caregivers for patients at risk for POD/POCD.

Patients and Methods

As part of a multicenter study, seven semi-structured focus group (FG) discussions with nurses and physicians from tertiary care hospitals (surgery, anesthesiology, and orthopedics, n=31) and general practitioners (GPs) in private practice (n=7) were performed. Transcribed discussions were analyzed using qualitative content analysis.

Results

POD is present above all in the daily work of nurses, whereas physicians do not perceive it as a relevant problem. Physicians report that no regular risk assessment or risk communication was performed prior to elective surgery. Information about POD often gets lost during hand-offs and is not regularly reported in discharge letters. Thus, persisting cognitive dysfunction is often missed. The importance of standardized documentation and continuous education concerning risks, screening, and treatment was emphasized. The often-suggested pre-OP medication adjustment was seen as less important; in contrast, avoiding withdrawal was regarded as far more important.

Conclusion

Altogether, it seems that standards and available best practice concepts are rarely implemented. In contrast to physicians, nurses are highly aware of delirium and ask for standardized procedures and more responsibility. Therefore, raising awareness regarding risks, screening tools, and effective preventive measures for POD/POCD seems an urgent goal. Nurses should have a central role in coordination and care of POD to prevent the risk for POCD.

Comparative Effect of Local Anesthesia with Lidocaine 2% Versus Topical Anesthesia on Cognitive Function in Ophthalmic Surgery

Background

Multiple clinical trials targeted the assessment of cognitive function following local versus general anesthesia in patients undergoing ophthalmic surgery, but no previous clinical trials have focused on the effect of topical anesthesia on cognitive function.

Objectives

This study aimed to compare the effect of local anesthesia with lidocaine 2% versus topical anesthesia with Oxybuprocaine (benoxinate hydrochloride 0.4%) on cognitive function in patients undergoing elective cataract surgery.

Methods

This is a prospective randomized clinical trial carried out on 60 patients undergoing elective cataract surgery by phacoemulsification. Thirty patients received local anesthesia with lidocaine 2% and thirty patients received topical anesthesia with Oxybuprocaine (benoxinate hydrochloride 0.4%). Patients’ satisfaction was assessed postoperatively using the Iowa satisfaction with anesthesia scale (ISAS). Cognitive assessment for all patients was done preoperatively and 1 week postoperatively using paired-associate learning test (PALT) and category verbal fluency (VF) test (animal category).

Results

There was no statistically significant difference between local and topical anesthesia groups in the mean of responses to the 11 statements of ISAS (P = 0.071). Regarding cognitive assessment, there was a statistically significant postoperative decline in the local anesthesia group in both PALT scores (P = 0.005) and VF scores (P = 0.01). In the topical anesthesia group, there was no statistically significant difference between pre- and postoperative PALT scores (P = 0.326) or VF scores (P = 0.199).

Conclusions

Postoperative cognitive dysfunction following elective cataract surgeries under local anesthesia can be attributed to the effect of local anesthesia rather than the effect of surgery.

Intraoperative hyperglycemia increases the incidence of postoperative delirium

BACKGROUND

Hyperglycemia frequently occurs during major surgery and is associated with adverse postoperative outcomes. This study aimed to investigate the influence of intraoperative hyperglycemia on incidences of postoperative delirium (POD) and postoperative cognitive dysfunction (POCD).

METHODS

Eighty-seven patients aged ≥65 years undergoing elective surgery were included in this prospective observational subproject of the BioCog study. Blood glucose (BG) levels were measured every 20 minutes intraoperatively. Hyperglycemia was defined as BG levels ≥150 mg·dL-1. Patients were assessed for POD twice daily until postoperative day 7. The occurrence of POCD was determined three months after surgery. Multivariable logistic regression was used to identify associations between hyperglycemia and POD as well as POCD. Secondary endpoints comprised duration of hyperglycemia, maximum glucose level (Glucosemax) and differences between diabetic and non-diabetic patients.

RESULTS

POD occurred in 41 (47.1%), POCD in five (15.2%) patients. In two separate multivariable logistic regression models, hyperglycemia was significantly associated with POD (OR 3.86 [CI 95% 1.13, 39.49], P=0.044) but not POCD (3.59 [NaN, NaN], P=0.157). Relative duration of hyperglycemia was higher in POD patients compared to patients without POD (20 [0; 71] % versus 0 [0; 55] %, P=0.075), whereas the maximum glucose levels during surgery were similar between the two groups. Considering only non-diabetic patients, relative duration of hyperglycemia (P=0.003) and Glucosemax (P=0.015) were significantly higher in patients with POD.

CONCLUSIONS

Intraoperative hyperglycemia was independently associated with POD but not POCD. Relative duration of hyperglycemia appeared thereby to also play a role. Especially hyperglycemic non-diabetic patients might be at high risk for POD.

Dexmedetomidine for the prevention of postoperative delirium in elderly patients undergoing noncardiac surgery: A meta-analysis of randomized controlled trials

BACKGROUND

Postoperative delirium (POD) among the elderly population that undergoes noncardiac surgery is significantly associated with adverse clinical outcomes. We conducted this meta-analysis to evaluate the effectiveness and safety of dexmedetomidine for the prophylaxis of POD among the elderly population after noncardiac surgery.

METHODS

We searched Embase, PubMed, and the Cochrane Library from inception date to March 2019 for randomized controlled trials (RCTs) that compared dexmedetomidine and placebo for the prevention of POD and evaluated the major cardiovascular outcomes among elderly people after noncardiac surgery. Two authors independently screened the studies and extracted data from the published articles. The main outcome was the incidence of POD. The secondary outcomes included the occurrence of bradycardia, hypotension, hypertension, tachycardia, myocardial infarction, stroke, hypoxaemia, and all-cause mortality.

RESULTS

A total of 6 RCTs with 2102 participants were included. Compared with placebo, dexmedetomidine significantly reduced the prevalence of POD (RR = 0.61, 95% CI 0.34-0.76, P = 0.001, I2 = 66%), and the risk of tachycardia (RR = 0.48, 95% CI 0.30-0.76, P = 0.002, I2 = 0%), hypertension (RR = 0.59, 95% CI 0.44-0.79, P < 0.001, I2 = 20%), stroke (RR = 0.22, 95% CI 0.06-0.76, P = 0.02, I2 = 0%), and hypoxaemia (RR = 0.50, 95% CI 0.32-0.78, P = 0.002, I2 = 0%) in elderly patients who underwent noncardiac surgery. However, dexmedetomidine accelerated the occurrence of bradycardia (RR = 1.36, 95% CI 1.11-1.67, P = 0.003, I2 = 0%). Furthermore, no significant differences were observed in the incidence of hypotension, myocardial infarction, and all-cause mortality between the dexmedetomidine and placebo groups.

CONCLUSIONS

Among elderly patients after noncardiac surgery, the prophylactic use of dexmedetomidine, compared with the use of placebo, was related to a decline in the incidence of POD.

Cerebral microbleeds are not associated with postoperative delirium and postoperative cognitive dysfunction in older individuals

Background

Cerebral microbleeds (CMB) occur in the context of cerebral small vessel disease. Other brain MRI markers of cerebral small vessel disease are associated with the occurrence of postoperative delirium (POD) and postoperative cognitive dysfunction (POCD), but for CMB this is unknown. We aimed to study the association between CMB and the occurrence of POD and POCD in older individuals.

Methods

The current study consists of 65 patients (72±5 years) from the BIOCOG study, which is a prospective, observational study of patients who underwent an elective surgery of at least 60 minutes. Patients in the current study received a preoperative cerebral MRI scan including a 3D susceptibility-weighted imaging sequence to detect CMB. The occurrence of POD was screened for twice a day until postoperative day 7 by using the DSM-5, NuDesc, CAM, and CAM-ICU. The occurrence of POCD was determined by the reliable change index model at 7 days after surgery or discharge, respectively, and 3 months after surgery. Statistical analyses consisted of logistic regression adjusted for age and gender.

Results

A total of 39 CMB were detected in 17 patients (26%) prior to surgery. POD occurred in 14 out of 65 patients (22%). POCD at 7 days after surgery occurred in 11 out of 54 patients (20%) and in 3 out of 40 patients at the 3 month follow-up (8%). Preoperative CMB were not associated with the occurrence of POD (OR (95%-CI): 0.28 (0.05, 1.57); p = 0.147) or POCD at 7 days after surgery (0.76 (0.16, 3.54); p = 0.727) or at 3 months follow-up (0.61 (0.03, 11.64); p = 0.740).

Conclusion

We did not find an association between preoperative CMB and the occurrence of POD or POCD.

Trial registration

clinicaltrials.gov (NCT02265263) on 23 September 2014.

Effect of dexmedetomidine on postoperative cognitive dysfunction and inflammation in patients after general anaesthesia: A PRISMA-compliant systematic review and meta-analysis

BACKGROUND

Neuroprotective effects of dexmedetomidine are reported in preclinical and clinical studies but evidence regarding the postoperative neurocognitive function is still unclear. This study performed a meta-analysis on outcomes of studies which examined neurocognitive performance and inflammatory factors to investigate the effects of dexmedetomidine on postoperative cognitive dysfunction (POCD) and inflammation in patients after general anaesthesia.

METHODS

Literatures were searched in several electronic databases and studies were selected by following precise inclusion criteria. We searched PubMed, EMBASE, the Cochrane Library, China Academic Journals full-text database (CNKI), and Google Scholar to find randomized controlled trials (RCTs) of the influence of dexmedetomidine on POCD and inflammation in patients who had undergone general anaesthesia. Two researchers independently screened the literature, extracted data, and evaluated quality of methodology against inclusion and exclusion criteria. Meta-analyses of pooled ORs of POCD incidences and mean differences in neurocognitive assessment scores and inflammation levels were carried out and subgroup analyses were performed. Stata 12.0 was used to conduct our meta-analysis.

RESULTS

Twenty-six RCTs were included. Compared with controls, perioperative dexmedetomidine treatment significantly reduced the incidence of POCD (pooled ORs = 0.59, 95% confidence interval (CI) 0.45-2.95) and improved Mini-Mental State Examination (MMSE) score (standardized mean difference (SMD) = 1.74, 95% CI 0.43-3.05) on the first postoperative day. Furthermore, perioperative dexmedetomidine treatment significantly decreased IL-6 (SMD = -1.31, 95% CI -1.87-0.75, P < .001) and TNF-α (SMD = -2.14, 95% CI -3.14-1.14, P < .001) compared to saline/comparators treatment. In the stratified analysis by surgical type, age, type of control, and study region, the differences were also significant between dexmedetomidine- and saline-treated patients.

CONCLUSION

Perioperative dexmedetomidine treatment is associated with significantly reduced incidence of POCD and inflammation and better neurocognitive function postoperatively in comparison with both saline controls and comparator anaesthetics.

Diabetes, but Not Hypertension and Obesity, Is Associated with Postoperative Cognitive Dysfunction

BACKGROUND/AIMS

Older people undergoing surgery are at risk of developing postoperative cognitive dysfunction (POCD), but little is known of risk factors predisposing patients to POCD. Our objective was to estimate the risk of POCD associated with exposure to preoperative diabetes, hypertension, and obesity.

METHODS

Original data from 3 randomised controlled trials (OCTOPUS, DECS, SuDoCo) were obtained for secondary analysis on diabetes, hypertension, baseline blood pressure, obesity (BMI ≥30 kg/m2), and BMI as risk factors for POCD in multiple logistic regression models. Risk estimates were pooled across the 3 studies.

RESULTS

Analyses totalled 1,034 patients. POCD occurred in 5.2% of patients in DECS, in 9.4% in SuDoCo, and in 32.1% of patients in OCTOPUS. After adjustment for age, sex, surgery type, randomisation, obesity, and hypertension, diabetes was associated with a 1.84-fold increased risk of POCD (OR 1.84; 95% CI 1.14, 2.97; p = 0.01). Obesity, BMI, hypertension, and baseline blood pressure were each not associated with POCD in fully adjusted models (all p > 0.05).

CONCLUSION

Diabetes, but not obesity or hypertension, is associated with increased POCD risk. Consideration of diabetes status may be helpful for risk assessment of surgical patients.

Pharmacologic interventions for preventing delirium in adult patients after cardiac surgery: Protocol of a systematic review and network meta-analysis

BACKGROUND

Delirium is common in adult patients undergoing cardiac surgery and related to a high morbidity and mortality. Although a variety of pharmacologic interventions have been applied in delirium prevention, there is still uncertainty concerning which drug is optimal. Thus, we plan to conduct a systematic review and network meta-analysis (NMA) of published studies to assess the efficacy and safety of pharmacologic interventions for preventing delirium among those patients.

METHODS

A systematic literature search will be conducted in Embase, PubMed, and the Cochrane Library. The primary outcome will be the incidence of postoperative delirium. Secondary outcomes will include all-cause mortality and length of hospital or intensive care unit stay. A frequentist NMA will be conducted using Stata version 14.0. The inconsistency between direct and indirect comparisons will be evaluated using a node splitting method. In addition, surface under the cumulative ranking area will be used to evaluate superiority of different treatments.

RESULTS

The findings of our review will be submitted to a peer-reviewed publication.

CONCLUSION

Our study will generate convincing evidence regarding the effectiveness and safety of different pharmacologic interventions for delirium prevention in cardiac surgery patients.

Use of statins and the risk of delirium in critically ill and surgical patients: Protocol of a systematic review and meta-analysis

BACKGROUND

The critically ill and surgical patients are at significant risk of delirium, which is associated with a high morbidity and mortality. The association between statin use and the incidence of delirium is still controversial. In this article, we will perform a systematic review and meta-analysis of published studies to evaluate the effectiveness of statins for the prophylaxis of delirium among critically ill and surgical patients.

METHODS

We will conduct a systematic literature search in EMBASE, PubMed, and the Cochrane Library from inception date to October 2018 for randomized controlled trials (RCTs) and observational studies (either cohort or case-control studies) investigating the association between use of statins and delirium risk. The Cochrane Collaboration's tool for evaluating the risk of bias and Newcastle-Ottawa scale (NOS) will be used to assess the methodological quality of RCTs and observational studies, separately. The primary outcome will be the risk of incident delirium associated with statin use. Pooled odds ratios (ORs) with corresponding 95% confidence intervals (CIs) will be calculated by a random-effects or fixed-effects model according to heterogeneity among included studies. Subgroup analyses, meta-regression method, and assessment of publication bias will be also performed. Statistical analyses will be conducted with RevMan (version 5.3.5) and Stata (version 14.0) software. In addition, the grading of recommendations assessment, development and evaluation (GRADE) approach will be applied to evaluate the quality of evidence.

RESULTS

The study will provide a high-quality synthesis and evaluate the effectiveness of statins for delirium prevention among critically ill and surgical patients.

CONCLUSIONS

The systematic review and meta-analysis will provide convincing evidence concerning the effect of statins against delirium in critically ill and surgical patients.

Tacrine(10)-Hupyridone Prevents Post-operative Cognitive Dysfunction via the Activation of BDNF Pathway and the Inhibition of AChE in Aged Mice

Post-operative cognitive dysfunction (POCD) could cause short-term or long-term cognitive disruption lasting weeks or months after anesthesia and surgery in elderly. However, no effective treatment of POCD is currently available. Previous studies indicated that the enhancement of brain-derived neurotrophic factor (BDNF) expression, and the elevation the cholinergic system, might be effective to prevent POCD. In this study, we have discovered that tacrine(10)-hupyridone (A10E), a novel acetylcholinesterase (AChE) inhibitor derived from tacrine and huperzine A, could prevent surgery-induced short-term and long-term impairments of recognition and spatial cognition, as evidenced by the novel object recognition test and Morris water maze (MWM) tests, in aged mice. Moreover, A10E significantly increased the expression of BDNF and activated the downstream Akt and extracellular regulated kinase (ERK) signaling in the surgery-treated mice. Furthermore, A10E substantially enhanced choline acetyltransferase (ChAT)-positive area and decreased AChE activity, in the hippocampus regions of surgery-treated mice, indicating that A10E could prevent surgery-induced dysfunction of cholinergic system, possibly via increasing the synthesis of acetylcholine and the inhibition of AChE. In conclusion, our results suggested that A10E might prevent POCD via the activation of BDNF pathway and the inhibition of AChE, concurrently, in aged mice. These findings also provided a support that A10E might be developed as a potential drug lead for POCD.

Intraoperative ketamine administration to prevent delirium or postoperative cognitive dysfunction: A systematic review and meta-analysis

BACKGROUND

Postoperative cognitive complications are associated with substantial morbidity and mortality. Ketamine has been suggested to have neuroprotective effects in various settings. This systematic review evaluates the effects of intraoperative ketamine administration on postoperative delirium and postoperative cognitive dysfunction (POCD).

METHODS

Medline, Embase and Central were searched to 4 March 2018 without date or language restrictions. We considered randomised controlled trials (RCTs) comparing intraoperative ketamine administration versus no intervention in adults undergoing surgery under general anaesthesia. Primary outcomes were postoperative delirium and POCD. Non-cognitive adverse events, mortality and length of stay were considered as secondary outcomes. Data were independently extracted. The quality of the evidence (GRADE approach) was assessed following recommendations from the Cochrane collaboration. Risk ratios were calculated for binary outcomes, mean differences for continuous outcomes. We planned to explore the effects of age, specific anaesthesia regimen, depth of anaesthesia and intraoperative haemodynamic events through subgroup analyses.

RESULTS

Six RCTs were included. The incidence of postoperative delirium did not differ between groups (4 trials, 557 patients, RR 0.83, 95% CI [0.25, 2.80]), but patients receiving ketamine seemed at lower risk of POCD (3 trials, 163 patients, RR 0.34, 95% CI [0.15, 0.73]). However, both analyses presented limitations. Therefore, the quality of the evidence (GRADE) was deemed low (postoperative delirium) and very low (POCD).

CONCLUSION

The effect of ketamine on postoperative delirium remains unclear but its administration may offer some protection towards POCD. Large, well-designed randomised trials are urgently needed to further clarify the efficacy of ketamine on neurocognitive outcomes.

Intraoperative Infusion of Dexmedetomidine for Prevention of Postoperative Delirium and Cognitive Dysfunction in Elderly Patients Undergoing Major Elective Noncardiac Surgery: A Randomized Clinical Trial

Importance

Postoperative delirium occurs in 10% to 60% of elderly patients having major surgery and is associated with longer hospital stays, increased hospital costs, and 1-year mortality. Emerging literature suggests that dexmedetomidine sedation in critical care units is associated with reduced incidence of delirium. However, intraoperative use of dexmedetomidine for prevention of delirium has not been well studied.

Objective

To evaluate whether an intraoperative infusion of dexmedetomidine reduces postoperative delirium.

Design, Setting, and Participants

This study was a multicenter, double-blind, randomized, placebo-controlled trial that randomly assigned patients to dexmedetomidine or saline placebo infused during surgery and for 2 hours in the recovery room. Patients were assessed daily for postoperative delirium (primary outcome) and secondarily for postoperative cognitive decline. Participants were elderly (>68 years) patients undergoing major elective noncardiac surgery. The study dates were February 2008 to May 2014.

Interventions

Dexmedetomidine infusion (0.5 µg/kg/h) during surgery and up to 2 hours in the recovery room.

Main Outcomes and Measures

The primary hypothesis tested was that intraoperative dexmedetomidine administration would reduce postoperative delirium. Secondarily, the study examined the correlation between dexmedetomidine use and postoperative cognitive change.

Results

In total, 404 patients were randomized; 390 completed in-hospital delirium assessments (median [interquartile range] age, 74.0 [71.0-78.0] years; 51.3% [200 of 390] female). There was no difference in postoperative delirium between the dexmedetomidine and placebo groups (12.2% [23 of 189] vs 11.4% [23 of 201], P = .94). After adjustment for age and educational level, there was no difference in the postoperative cognitive performance between treatment groups at 3 months and 6 months. Adverse events were comparably distributed in the treatment groups.

Conclusions and Relevance

Intraoperative dexmedetomidine does not prevent postoperative delirium. The reduction in delirium previously demonstrated in numerous surgical intensive care unit studies was not observed, which underscores the importance of timing when administering the drug to prevent delirium.

Trial Registration

clinicaltrials.gov Identifier NCT00561678.

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.

Postoperative delirium in patients with history of alcohol abuse

INTRODUCTION

Postoperative delirium (POD) is an acute confusional state characterized by changes in consciousness and cognition, which may be fluctuating, developing in a small period of time. The aim of this study was to evaluate the relationship between alcohol abuse and the development of POD.

METHODS

We prospectively evaluated consecutively all postoperative patients admitted in the Post-anesthesia Care Unit over a 1-month period for delirium, using the Portuguese versions of the the Nursing Delirium Screening Scale. Before surgery, alcohol consumption was inquired and alcohol abuse was assessed by the CAGE (Cutting Down, Annoyance, Guilt and Eye-opener) questionnaire; a score ≥2 defined alcohol abuse. Fischer exact test or chi-square was applied for comparisons. Risk factors were analyzed in a multivariate analysis using a logistic regression with odds ratios (OR) and 95% confidence intervals (95%CI).

RESULTS

Two hundred twenty-one patients were enrolled. Delirium was seen in 11% patients. The incidence of alcohol abuse was 10%. Patients with alcohol abuse were more frequently men (P<.001) and had a higher ASA physical status III/IV (P=.021). POD was more frequent in patients with alcohol abuse (30% vs. 9%; P=.002). Age (OR: 5.9; 95%CI: 2.2-15.9; P<.001 for patients ≥65years), ASA physical statusIII/IV (OR: 4.2; 95%CI: 1.7-10.7; P=.002) and alcohol abuse (OR: 4.2; 95%CI: 1.4-12.9; P=.013) were found to be independent predictors for POD.

CONCLUSIONS

Older patients, higher ASA physical status and alcohol abuse were more frequent in patients with POD. Alcohol abuse was considered an independent risk factor for POD.

[Joint replacement in the elderly]

Special characteristics must be taken into consideration for replacement arthroplasty in the elderly. The indications, preoperative preparation, postoperative care, implant selection, intraoperative technique, as well as clinical results reveal sometimes substantial differences compared to younger patients. Based on these findings it is important to individualize the approach to patient therapy, especially due to distinct differences between chronological and biological age in the elderly, in association with the level of activity and expectations on the new joint. All types of implants, each with implant-specific characteristics that must be taken into consideration, are available independent of the age of the patient. In summary, attributes such as stability and pain-free mobility have to be given priority in the elderly.