Beyond Cognitive Screening: Establishing an Interprofessional Perioperative Brain Health Initiative

Advancing Perioperative Neurocognitive Health: A Critical Review of Predictive Tools, Diagnostic Methods, and Interventional Strategies

Perioperative neurocognitive disorders (PNDs) affect a large percentage of people who undergo surgeries that need general anesthesia. There is an increased risk of death and a major disruption to postoperative self-care as a result of this. This study compiles all the relevant materials that the authors have found to investigate postnatal depression and its causes, as well as the methods used to determine the probability and severity of PNDs and how to reduce their risk before surgery. Postnatal depression can have many causes, and this text explores some of them. These include a history of alcohol or opiate use, immunological dysregulation, advanced age, educational background, infections, neurocognitive impairment, and pre-existing chronic inflammatory disorders. It also delves into various methods used to gauge the likelihood and severity of postpartum depression. The following assessment tools were covered: the Clock Drawing Test, Domain-Specific Tests, the Mini-Mental State Examination, and the Montreal Cognitive Assessment. In addition to biochemical markers, neuroimaging techniques play an important role in diagnosis. The Frailty Fried assessment, which measures inertia, sluggishness, lack of physical activity, fatigue, and unintentional weight loss, is a key prognostic sign that is highlighted. There is strong evidence that the index, which is derived from these five characteristics, may accurately predict the likelihood of PNDs. Risk mitigation strategies are also covered in this research. Preoperative brain plasticity-based therapies, such as physical exercise and intensive cognitive training, can significantly reduce the incidence and severity of postoperative neurocognitive disorders. A peripheral nerve block, monitoring cerebral oxygen saturation, dexmedetomidine, and a reduction in anesthesia depth are all ways to improve anesthetic procedures. Methods that lower blood pressure should be avoided, the body temperature should be kept down during surgery, or the time without liquids should be lengthened; all of these raise the risk of postoperative nausea and vomiting and make it worse. Potential approaches include a Mediterranean diet, physical activity, cognitive stimulation, smoking cessation, alcohol reduction, avoidance of anticholinergic medications, and non-steroidal anti-inflammatory drug stewardship, although there is no definitive evidence for successful postoperative neurocognitive rehabilitation procedures. More standardized diagnostic criteria, evaluation methods, and PND classification are urgently needed, according to this study. Different cases of PNDs are characterized by different combinations of tests, cutoff values, and methods because there is a broad variety of diagnostic tests used to make the diagnosis. Until now, PNDs and pre-existing neurocognitive disorders have been diagnosed using the Diagnostic and Statistical Manual of Mental Disorders (DSM-V). With an aging population comes an increase in the occurrence and prevalence of PNDs, which calls for a specific way to classify and describe the condition.

Melanin-Concentrating Hormone Is Associated With Delayed Neurocognitive Recovery in Older Adult Patients With Preoperative Sleep Disorders Undergoing Spinal Anesthesia

BACKGROUND

Aging and preoperative sleep disorders are the main risk factors affecting postoperative cognitive outcomes. However, the pathogenesis of delayed neurocognitive recovery after surgery remains ambiguous, and there is still a lack of potential biomarkers for delayed neurocognitive recovery in older adult patients with preoperative sleep disorders. Our study aimed to explore the relationship between melanin-concentrating hormone (MCH) and delayed neurocognitive recovery early after surgery in older adult patients with preoperative sleep disorders.

METHODS

In this monocentric prospective observational study, 156 older adult patients (aged 65 years or older) with preoperative sleep disorders undergoing elective total hip arthroplasty (THA) or total knee arthroplasty (TKA) were included at an academic medical center in Inner Mongolia, China, from October 2021 to November 2022, and all patients underwent spinal anesthesia. The Pittsburgh Sleep Quality Index (PSQI) was applied to assess the preoperative sleep quality of all patients, and preoperative sleep disorders were defined as a score of PSQI >5. We measured the levels of cerebrospinal fluid (CSF) MCH and plasma MCH of all patients. The primary outcome was delayed neurocognitive recovery early after surgery. All patients received cognitive function assessment through the Montreal Cognitive Assessment (MoCA) 1 day before and 7 days after surgery (postoperative day 7 [POD7]). Delayed neurocognitive recovery was defined as a score of POD7 MoCA <26. The potential confounders included variables with P < .2 in the univariate logistic analysis, as well as the important risk factors of delayed neurocognitive recovery reported in the literature. Multivariable logistic regression model based on the Enter method assessed the association of MCH and delayed neurocognitive recovery in older adult patients with preoperative sleep disorders.

RESULTS

Fifty-nine (37.8%) older adult patients with preoperative sleep disorders experienced delayed neurocognitive recovery at POD7. Increase in CSF MCH levels (odds ratio [OR] for an increase of 1 pg/mL = 1.16, 95% confidence interval [CI], 1.09-1.23, P < .001) and decrease in plasma MCH levels (OR for an increase of 1 pg/mL = 0.92, 95% CI, 0.86-0.98, P = .003) were associated with delayed neurocognitive recovery, after adjusting for age, sex, education, baseline MoCA scores, American Society of Anesthesiologists (ASA) grade, and coronary heart disease (CHD).

CONCLUSIONS

In older adult patients with preoperative sleep disorders, MCH is associated with the occurrence of delayed neurocognitive recovery after surgery. Preoperative testing of CSF MCH or plasma MCH may increase the likelihood of identifying the high-risk population for delayed neurocognitive recovery in older adult patients with preoperative sleep disorders.

Perioperative Evaluation of Brain Health

As the global population is aging and surgical needs rise, the occurrence of perioperative neurocognitive disorders (PND) is becoming a significant concern. PND refers to cognitive changes that occur before or after surgery, including neurocognitive disorders, postoperative delirium, and delayed neurocognitive recovery. To address this issue, a brain health assessment initiative within a multidisciplinary team is an emerging concept. Assessing cognitive function, comorbidities, severity of neurocognitive disorders, medications, nutritional status, sleep quality, and other factors can help mitigate the risk of PND and improve patient outcomes.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Research progress of postoperative cognitive dysfunction in cardiac surgery under cardiopulmonary bypass

Cardiopulmonary bypass (CPB) is often used in cardiothoracic surgery because its nonphysiological state causes pathophysiological changes in the body, causing multiorgan and multitissue damage to varying degrees. Postoperative cognitive dysfunction (POCD) is a common central nervous system complication after cardiac surgery. The etiology and mechanism of POCD are not clear. Neuroinflammation, brain mitochondrial dysfunction, cerebral embolism, ischemia, hypoxia, and other factors are related to the pathogenesis of POCD. There is a close relationship between CPB and POCD, as CPB can cause inflammation, hypoxia and reperfusion injury, and microemboli formation, all of which can trigger POCD. POCD increases medical costs, seriously affects patients' quality of life, and increases mortality. Currently, there is a lack of effective treatment methods for POCD. Commonly used methods include preoperative health management, reducing inflammation response during surgery, preventing microemboli formation, and implementing individualized rehabilitation programs after surgery. Strengthening preventive measures can minimize the occurrence of POCD and its adverse effects.

Preoperative Cognitive Impairment and Postoperative Delirium in Elderly Surgical Patients: A Retrospective Large Cohort Study (The CIPOD Study)

OBJECTIVE

To test the hypothesis that in surgical patients ≥70 years, preoperative cognitive impairment is independently associated with postoperative delirium.

BACKGROUND

Postoperative delirium is common among elderly surgical patients and is associated with longer hospitalization and significant morbidity. Some evidence suggest that baseline cognitive impairment is an important risk factor. Routine screening for both preoperative cognitive impairment and postoperative delirium is recommended for older surgical patients. As of 2019, we implemented such routine perioperative screening in all elective surgical patients ≥70 years.

METHODS

Retrospective single-center analysis of prospectively collected data between January and December 2020. All elective noncardiac surgical patients ≥70 years without pre-existing dementia were included. Postoperative delirium, defined as 4A's test score ≥4, was evaluated in the postanesthesia care unit and during the initial 2 postoperative days. Patients' electronic records were also reviewed for delirium symptoms and other adverse outcomes.

RESULTS

Of 1518 eligible patients, 1338 (88%) were screened preoperatively [mean (SD) age 77 (6) years], of whom 21% (n=279) had cognitive impairment (Mini-Cog score ≤2). Postoperative delirium occurred in 15% (199/1338). Patients with cognitive impairment had more postoperative delirium [30% vs. 11%, adjusted odds ratio (95% confidence interval) 3.3 (2.3-4.7)]. They also had a higher incidence of a composite of postoperative complications [20% vs. 12%, adjusted odds ratio: 1.8 (1.2-2.5)], and median 1-day longer hospital stay [median (interquartile range): 6 (3,12) vs. 5 (3,9) days].

CONCLUSIONS

One-fifth of elective surgical patients ≥70 years present to surgery with preoperative cognitive impairment. These patients are at increased risk of postoperative delirium and major adverse outcomes.

Perioperative Neurocognitive Disorders in Adults Requiring Cardiac Surgery: Screening, Prevention, and Management

Neurocognitive changes are the most common complication after cardiac surgery, ranging from acute postoperative delirium to prolonged postoperative neurocognitive disorder. Changes in cognition are distressing to patients and families and associated with worse outcomes overall. This review outlines definitions and diagnostic criteria, risk factors for, and mechanisms of Perioperative Neurocognitive Disorders and offers strategies for preoperative screening and perioperative prevention and management of neurocognitive complications.

Age-Related Perioperative Neurocognitive Disorders: Experimental Models and Druggable Targets

With the worldwide increase in life span, surgical patients are becoming older and have a greater propensity for postoperative cognitive impairment, either new onset or through deterioration of an existing condition; in both conditions, knowledge of the patient's preoperative cognitive function and postoperative cognitive trajectory is imperative. We describe the clinical utility of a tablet-based technique for rapid assessment of the memory and attentiveness domains required for executive function. The pathogenic mechanisms for perioperative neurocognitive disorders have been investigated in animal models in which excessive and/or prolonged postoperative neuroinflammation has emerged as a likely contender. The cellular and molecular species involved in postoperative neuroinflammation are the putative targets for future therapeutic interventions that are efficacious and do not interfere with the surgical patient's healing process.

Identification of individuals at risk for postoperative cognitive dysfunction (POCD)

Postoperative cognitive dysfunction (POCD) is common, occurring in around 10-54% of individuals within first few weeks after surgery. Although the majority of POCD is less commonly persistent later than 3 months following surgery, the condition increases length of stay (LOS), mortality and long-term cognitive decline, raising the need for a broad screening to identify individuals at risk for POCD during the perioperative period. In this narrative review, we summarize preoperative, intraoperative and postoperative risk factors for POCD reported in last 5 years and discuss neuropsychological tools and potential biomarkers and time points for assessment that might be suitable for clinical use. We aim to provide crucial information for developing a strategy of routine screening for POCD, which may assist with better identification of at-risk individuals for early interventions. Very importantly, the utilization of a standardized strategy may also allow higher consistency and comparability across different studies.

A proposal for virtual, telephone-based preoperative cognitive assessment in older adults undergoing elective surgery

OBJECTIVE

To assess the feasibility of administering the MoCA 5-minute test/Telephone (T-MoCA), an abbreviated version of the Montreal Cognitive Assessment to older adults perioperatively DESIGN: A feasibility study including patients aged ≥ 70 years scheduled for surgery from December 2020 to March 2021 SETTING: Preoperative virtual clinic PATIENTS: Patients ≥70 years undergoing major elective surgery INTERVENTION: A study investigator called eligible patients prior to surgery, obtained consent, and completed the preoperative cognitive assessment. Follow-up assessment was completed 1-month postoperatively, and participating clinicians were surveyed at the completion of the study.

MEASUREMENTS

An attention test, T-MoCA, Activities of Daily Living (ADL), Instrumental Activities of Daily Living (IADL), and Generalized Anxiety Disorder 2-item (GAD-2) MAIN RESULTS: Overall, 37/40 (92.5%) patients completed the pre- and post-operative assessments. The cohort was 50% female, white (97.5%), with a median age of 76 years (interquartile range (IQR) 73-79), and education level was higher than high school in 82.5% of patients. Preoperatively, the median number of medications was 8 (IQR 7-11), 27/40 (67.5%) had medications with anticholinergic effects, and 6/40 (15%) had benzodiazepines. Median completion time of the phone assessment was 10 min (IQR 8.25-12) and 4 min (IQR 3-5) for the T-MoCA with a median T-MoCA score of 13 (IQR 12-14). Most patients (37/40) completed the post-operative assessment, and 6/37 (16.2%) reported they had experienced a change in memory or attention post-operatively. Clinician's survey reported ease and feasibility in performing T-MoCA as a preoperative cognitive evaluation.

CONCLUSION

Preoperative cognitive assessment of older adults using T-MoCA over the phone is easy to perform by clinicians and had a high completion rate by patients. This test is feasible for virtual assessments. Further research is needed to better define validity and correlation with postoperative outcomes.

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.

Risk assessment of perioperative neurocognitive disorders, where are we now?

PURPOSE OF REVIEW

Perioperative neurocognitive disorders (PNDs) are among the most frequent complications after surgery and are associated with considerable morbidity and mortality. We analysed the recent literature regarding risk assessment of PND.

RECENT FINDINGS

Certain genetic variants of the cholinergic receptor muscarinic 2 and 4, as well as a marked degree of frailty but not the kind of anaesthesia (general or spinal) are associated with the risk to develop postoperative delirium (POD). Models predict POD with a discriminative power, for example, area under the receiver operating characteristics curve between 0.52 and 0.94.

SUMMARY

Advanced age as well as preexisting cognitive, functional and sensory deficits remain to be the main risk factors for the development of PND. Therefore, aged patients should be routinely examined for both preexisting and new developing deficits, as recommended in international guidelines. Appropriate tests should have a high discrimination rate, be feasible to be administered by staff that do not require excessive training, and only take a short time to be practical for a busy outpatient clinic. Models to predict PND, should be validated appropriately (and externally if possible) and should not contain a too large number of predictors to prevent overfitting of models.

Does Preoperative Cognitive Optimization Improve Postoperative Outcomes in the Elderly?

Perioperative neurocognitive disorder (PND) is a growing concern, affecting several million elderly patients each year in the United States, but strategies for its effective prevention have not yet been established. Humeidan et al. recently demonstrated that preoperative brain exercise resulted in a decrease in postoperative delirium incidence in elderly surgical patients, suggesting the potential of presurgical cognitive optimization to improve postoperative cognitive outcomes. This brief review summarizes the current knowledge regarding preoperative cognitive optimization and highlights landmark studies, as well as current ongoing studies, as the field is rapidly growing. This review further discusses the benefit of cognitive training in non-surgical elderly populations and the role of cognitive training in patients with preexisting cognitive impairment or dementia. The review also examines preclinical evidence in support of cognitive training, which can facilitate understanding of brain plasticity and the pathophysiology of PND. The literature suggests positive impacts of presurgical cognitive optimization, but further studies are encouraged to establish effective cognitive training programs for elderly presurgical patients.

Gut microbiota: a new player in the pathogenesis of perioperative neurocognitive disorder?

Perioperative neurocognitive disorder (PND), including postoperative delirium and postoperative cognitive dysfunction (POCD), is a common postoperative complication in elderly patients, who represent an expanding segment of our population. PND is a multifactorial disease resulting in higher morbidity and mortality. The precise mechanism of PND is yet to be fully delineated. Identifying the modifiable risk factors and mechanisms for PND would be an important step forward in preventing such adverse events and thus improving patients' outcomes. It is increasingly recognized that gut microbiota also manifest effects in the central nervous system via the microbiota-gut-brain axis, which has emerged as an important player in shaping aspects of behavior and cognitive function. Recent studies have found that patients with cognitive dysfunction after surgery and anesthesia have obvious gut microbiome disorders. These findings are paralleled by a growing body of preclinical investigations aimed at better understanding how surgery and anesthesia affect the central nervous system and possibly contribute to cognitive decline. Here, we present a broad topical review of the literature supporting the role of gut microbiota in PND. We provide an overview of the mechanisms underlying the pathogenesis of PND from pre-clinical and human studies. Therefore, gut microbiota could be a putative therapeutic target for PND in the future.

Improving perioperative brain health: an expert consensus review of key actions for the perioperative care team

Delirium and postoperative neurocognitive disorder are the commonest perioperative complications in patients more than 65 yr of age. However, data suggest that we often fail to screen patients for preoperative cognitive impairment, to warn patients and families of risk, and to take preventive measures to reduce the incidence of perioperative neurocognitive disorders. As part of the American Society of Anesthesiologists (ASA) Perioperative Brain Health Initiative, an international group of experts was invited to review published best practice statements and guidelines. The expert group aimed to achieve consensus on a small number of practical recommendations that could be implemented by anaesthetists and their partners to reduce the incidence of perioperative neurocognitive disorders. Six statements were selected based not only on the strength of the evidence, but also on the potential for impact and the feasibility of widespread implementation. The actions focus on education, cognitive and delirium screening, non-pharmacologic interventions, pain control, and avoidance of antipsychotics. Strategies for effective implementation are discussed. Anaesthetists should be key members of multidisciplinary perioperative care teams to implement these recommendations.