Cognitive impairment assessment and interventions to optimize surgical patient outcomes

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.

Co-design and mixed methods evaluation of an interdisciplinary digital resource for undergraduate health profession students to improve the prevention, recognition, and management of delirium in Ireland: a study protocol

BACKGROUND

Delirium is a common symptom of acute illness which is potentially avoidable with early recognition and intervention. Despite being a growing concern globally, delirium remains underdiagnosed and poorly reported, with limited understanding of effective delirium education for undergraduate health profession students. Digital resources could be an effective approach to improving professional knowledge of delirium, but studies utilising these with more than one profession are limited, and no evidence-based, interdisciplinary, digital delirium education resources are reported. This study aims to co-design and evaluate a digital resource for undergraduate health profession students across the island of Ireland to improve their ability to prevent, recognise, and manage delirium alongside interdisciplinary colleagues.

METHODS

Utilising a logic model, three workstreams have been identified. Workstream 1 will comprise three phases: (1) a systematic review identifying the format, methods, and content of existing digital delirium education interventions for health profession students, and their effect on knowledge, self-efficacy, and behavioural change; (2) focus groups with health profession students to determine awareness and experiences of delirium care; and (3) a Delphi survey informed by findings from the systematic review, focus groups, and input from the research team and expert reference group to identify resource priorities. Workstream 2 will involve the co-design of the digital resource through workshops (n = 4) with key stakeholders, including health profession students, professionals, and individuals with lived experience of delirium. Lastly, Workstream 3 will involve a mixed methods evaluation of the digital resource. Outcomes include changes to delirium knowledge and self-efficacy towards delirium care, and health profession students experience of using the resource.

DISCUSSION

Given the dearth of interdisciplinary educational resources on delirium for health profession students, a co-designed, interprofessional, digital education resource will be well-positioned to shape undergraduate delirium education. This research may enhance delirium education and the self-efficacy of future health professionals in providing delirium care, thereby improving practice and patients' experiences and outcomes.

TRIAL REGISTRATION

Not applicable.

Cognitive function and ability to complete a web-based geriatric assessment among older adults with cancer

BACKGROUND

The purpose of this study was determined whether cognitive impairment is associated with time taken to complete the electronic rapid fitness assessment (eRFA). We hypothesized that taking more time to complete the eRFA will indicate worsened cognitive function.

METHODS

We retrospectively identified patients who presented to the Memorial Sloan Kettering Cancer Center Geriatrics Service for preoperative evaluation and completed the eRFA as a part of their preoperative assessment from February 2015 to December 2020. Cognitive function was assessed using the Mini-Cog©, which is a screening test for cognitive function status. Patients in this study underwent elective surgery and had a hospital length of stay ≥1 day. Time to complete the eRFA was automatically recorded by a web-based tool; assistance with eRFA completion was self-reported by the patient. In total, 2599 patients were included, of which 2387 had available Mini-Cog© scores.

RESULTS

Overall, 50% of surveys were completed without assistance, 37% were completed with assistance, and 13% were completed by somebody else; Mini-Cog© scores were lower, corresponding to worsened cognitive function status, in patients requiring assistance (median score respectively, 5 vs. 4 vs. 3; p-value <0.0001; rates of cognitive impairment 7.5%, 22%, and 38%). Among patients who completed the questionnaire independently, greater cognitive impairment was associated with longer time to complete the eRFA (change in score per 5 min = -0.09; 95% CI -0.14, -0.03; p = 0.002).

CONCLUSIONS

We found evidence that requirement for assistance in completing web-based questionnaires, and time taken to complete a questionnaire, predict which patients benefit from more comprehensive cognitive function assessments. Future studies should further validate this finding in a more diverse population and establish optimal clinical pathways.

Dementia is Associated With Inferior Outcomes Following Emergency General Surgery

INTRODUCTION

Given the steadily aging United States population, we used a national database to examine the association of dementia with clinical and financial outcomes following emergency general surgery.

METHODS

All adults undergoing non-elective appendectomy, cholecystectomy, small bowel resection, large bowel resection, repair of perforated ulcer, or lysis of adhesions were identified within the 2016-2019 Nationwide Readmissions Database. Entropy balancing and multivariable regressions were used to assess the risk-adjusted association between dementia and in-hospital mortality, complications, length of stay, costs, non-home discharge, and 30-day unplanned readmissions.

RESULTS

Of an estimated 1,332,922 patients, 2.7% had dementia. Compared to those without, patients with dementia were older, more commonly male, and had a greater burden of chronic conditions. Following entropy balancing and multivariable risk-adjustment, dementia was associated with increased odds of mortality and sepsis across all operations except perforated ulcer repair. Dementia was also linked to greater likelihood of pneumonia across all operative categories. Moreover, dementia was associated with increased length of stay for patients in all operative categories except perforated ulcer repair, while costs were only increased for those undergoing appendectomy, cholecystectomy, and lysis of adhesions. Dementia was also linked to higher odds of non-home discharge following all operations, while non-elective readmissions were only increased for patients undergoing cholecystectomy.

CONCLUSIONS

The present study found dementia to be associated with a significant clinical and financial burden. Our findings may help inform shared decision making with patients and their families.

Effects of Different Injection Rates of Propofol on Postoperative Cognition in Elderly Patients Undergoing Laparoscopic Inguinal Hernia Repair

Purpose

This study aimed to explore the effects of different injection rates of propofol on postoperative cognition in elderly patients undergoing laparoscopic inguinal hernia repair.

Methods

A total of 180 elderly patients who planned to undergo laparoscopic inguinal hernia repair were randomly divided into three groups: slow injection of propofol (V_S-Group, 30 mg kg^-1 h^-1); medium injection of propofol (V_M-Group, 100 mg kg^-1 h^-1) or fast injection of propofol (V_F-Group, 300 mg kg^-1 h^-1). Propofol was induced by microinfusion pump, and the depth of anesthesia was monitored by bispectral index (BIS). Propofol and remifentanil were continuously infused during anesthesia maintenance and adjusted according to BIS. The primary outcome was the use of the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA) to measure the incidence of postoperative cognitive decline (POCD) in elderly patients on the first and seventh postoperative day. Secondary outcomes included induced dose of propofol, incidence of burst suppression and maximum electroencephalographic (EEG) effect of propofol (BIS-min) during induction.

Results

The incidence of POCD on the first and seventh day postoperatively was similar among the three groups (P > 0.05). However, with the increase of propofol injection rate, induced dose of propofol, incidence of burst suppression and BIS-min during induction, the number of patients requiring vasoactive agents were significantly increased (P < 0.001). Multivariate regression analysis showed that the brief duration of burst suppression during induction did not affect the occurrence of POCD, while age and duration of hospitalization were risk factors for POCD.

Conclusion

For elderly patients undergoing laparoscopic inguinal hernia repair, lowering the injection rate of propofol (such as 30 mg kg^-1 h^-1) cannot decrease the incidence of early POCD, but reduces induction dose of propofol and use of vasoactive drugs, making the patient's hemodynamics more stable.

Preoperative frailty vs. cognitive impairment: Which one matters most for postoperative delirium among older adults with cancer?

INTRODUCTION

Limited data are available to explore the association between preoperative frailty and cognitive impairment with postoperative delirium among older adults with cancer. We explored this association in a single Comprehensive Cancer Center where postoperative delirium and frailty are assessed in routine care using the Confusion Assessment Method (CAM) and Memorial Sloan Kettering Frailty Index (MSK-FI), respectively.

MATERIALS AND METHODS

Retrospective study on patients with cancer, aged 65+, who underwent surgery from April 2018 to March 2019 with hospital stay ≥1 day. We used logistic regression with postoperative delirium as the outcome, primary predictor MSK-FI, adjusted for age, operative time, and preoperative albumin. As the MSK-FI includes a component related to cognitive impairment, we additionally evaluated the impact of this component, separately from the rest of the score, on the association between frailty and postoperative delirium.

RESULTS

Among 1,257 patients with available MSK-FI and CAM measures, 47 patients (3.7%) had postoperative delirium. Increased frailty was associated with increased risk of postoperative delirium (odds ratio [OR] 1.51; 95% confidence interval [CI] 1.26, 1.81; p < 0.001). However, this was largely related to the effect of cognitive impairment (OR 15.29; 95% CI 7.18; 32.56; p < 0.001). In patients with cognitive impairment, the association between frailty and postoperative delirium was not significant (OR 0.97; 95% CI 0.65, 1.44; p-value = 0.9), as having cognitive impairment put patients at high risk for postoperative delirium even without taking into account the other components of the MSK-FI. While the association between frailty and postoperative delirium in patients with intact cognitive function was statistically significant (OR 1.58; 95% CI 1.27, 1.96; p < 0.001), it was not clinically meaningful, particularly considering the low risk of delirium among patients with intact cognitive function (e.g., 1.3% vs 3.2% for MSK-FI 1 vs 3).

DISCUSSION

Cognitive function should be a greater focus than frailty, as measured by the MSK-FI, in preoperative assessment for the prediction of postoperative delirium.

Postoperative Application of Dexmedetomidine is the Optimal Strategy to Reduce the Incidence of Postoperative Delirium After Cardiac Surgery: A Network Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Previous pairwise meta-analyses demonstrated the efficacy and safety of dexmedetomidine in preventing postoperative delirium (POD) after cardiac surgery; however, the optimal time of applying dexmedetomidine remains unclear.

OBJECTIVE

This network meta-analysis aimed to determine the optimal time of using dexmedetomidine to reduce the incidence of POD following cardiac surgery.

METHODS

We first retrieved eligible randomized controlled trials (RCTs) from previous meta-analyses, and then an updated search was performed to identify additional RCTs in PubMed, Embase, and the Cochrane library from January 1, 2021 to October 31, 2021. Two authors screened literature, collected data, and evaluated bias risk of eligible studies. Finally, we performed Bayesian network analysis using R version 3.6.1 with the "gemtc" and "rjags" package.

RESULTS

Eighteen studies with 2636 patients were included, and all studies were identified from previous meta-analyses. Results showed that postoperative dexmedetomidine reduced the risk of POD compared with normal saline (NS) (odds ratio [OR], 0.13; 95% credible interval [CrI], 0.03-0.35) and propofol (PRO) (OR, 0.19; 95%CrI, 0.04-0.66). Postoperative dexmedetomidine was associated with a lower incidence of POD compared with perioperative dexmedetomidine (OR, 0.21; 95% CrI, 0.04-0.82). Moreover, postoperative dexmedetomidine had the highest probability of ranking best (90.98%), followed by intraoperative dexmedetomidine (46.83%), PRO (36.94%), perioperative dexmedetomidine (30.85%), and NS (60.02%).

CONCLUSION AND RELEVANCE

Dexmedetomidine reduces the incidence of POD compared with PRO and NS in patients undergoing cardiac surgery, and postoperative application of dexmedetomidine is the optimal time.

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.

Future Perspectives on Prehabilitation Interventions in Cancer Surgery

OBJECTIVE

This article provides a map of key knowledge gaps regarding the evidence supporting prehabilitation and its integration with enhanced recovery after surgery (ERAS) programs. Filling this lack of knowledge with future research will further establish the effectiveness of prehabilitation.

DATA SOURCES

These are electronic databases including PubMed and CINAHL.

CONCLUSION

Future efforts must embrace the elderly frail or cognitively impaired patient with specific needs to further promote restoration of postoperative function throughout the surgical pathway. Prehabilitation should be coupled and integrated within the existent concept of the ERAS framework, to facilitate the continuous evolution of screening, assessment, and optimization of high-risk surgical patients who are at risk of not being restored to physical and psychological function after surgery, including independence.

IMPLICATIONS FOR NURSING PRACTICE

In the future, the ERAS nurse will be an essential figure of the prehabilitation program, proactively coordinating the assessment, optimization, and adjustment of perioperative comorbidity and guiding the rehabilitation process to improve patients' outcomes. These skills and characteristics will be required to provide optimal nursing care in the context of an integrated prehabilitation ERAS pathway.

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.

Comparison of Postoperative Cognitive Decline Using the Mini-Mental State Examination and Montreal Cognitive Assessment After Minor Elective Surgery in Elderly

Introduction and aim

Postoperative cognitive dysfunction (POCD) is an important complication associated with increased morbidity, mortality, and reduced quality of life. Generally, studies have focused on major surgery so there is little evidence of the incidence of cognitive dysfunction in minor surgery. We aimed to compare the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) in terms of detecting cognitive decline in elderly patients after elective inguinal herniorrhaphy procedure with general or spinal anesthesia.

Material and methods

This observational study was conducted from June 2014 to March 2015 at Ankara Numune Education and Research Hospital. The type of anesthesia was determined according to the anesthesiologist’s preference who is blind to the study. Patients were grouped according to anesthesia received: general or spinal anesthesia. The MMSE and MoCA were evaluated presurgery and 24 hours after the operation.

Results

The postoperative (24th hour) MMSE scores of patients (26.23±2.77) were significantly lower than the preoperative scores (27.17±1.93) in only the general anesthesia group (p =0.003). The postoperative (24th hour) MoCA scores (22.87±3.88 for general and 23.13±4.08 for spinal anesthesia) were significantly lower than the preoperative scores (24.32±3.19 for general and 24.35±2.84 for spinal anesthesia) in both the general and spinal anesthesia groups (p =0.000 and 0.019, respectively). The incidence of postoperative cognitive dysfunction was 32.9% using the MoCA and 15.2% using the MMSE (p=0,018).

Conclusion

Early POCD is an important problem after elective minor surgeries, even with spinal anesthesia, in elderly patients. The MoCA is an alternative tool that can be more sensitive than the MMSE to identify cognitive decline in elderly patients undergoing minor surgeries under both general and spinal anesthesia. 

The Association Between Hearing Loss and Surgical Complications in Older Adults

OBJECTIVES

In this study, we sought to evaluate whether older patients with hearing loss who underwent surgery were at greater risk of postsurgical complications, increased inpatient length-of-stay (LOS), and hospital readmission.

DESIGN

This was a retrospective cohort study of patients receiving surgery at a tertiary medical center. Utilizing electronic health record data from two merged datasets, we identified patients 65 years and older, undergoing major surgery between January 1, 2014 and January 31, 2017, and who had audiometric evaluation before surgery. Patients were classified as having either normal hearing or hearing loss based on pure-tone average in the better ear. A Generalized Estimating Equations approach was used to fit multivariable regression models for outcome variables of interest.

RESULTS

Of patients ≥65 years undergoing major surgery in our time frame, a total of 742 surgical procedures were performed on 621 patients with available audiometric data. After adjusting for age, sex, race, and comorbidities, hearing loss was associated with an increase in the odds of developing postoperative complications. Every 10 dB increase in hearing loss was associated with a 14% increase in the odds of developing a postoperative complication (odds ratio = 1.14, 95% confidence interval = 1.01-1.29, p = 0.031). Hearing loss was not significantly associated with increased hospital LOS, 30-day readmission, or 90-day readmission.

CONCLUSION

Hearing loss was significantly associated with developing postoperative complications in older adults undergoing major surgery. Screening for hearing impairment may be a useful addition to the preoperative assessment and perioperative management of older patients undergoing surgery.

Is Perioperative Dexmedetomidine Associated With a Reduced Risk of Perioperative Neurocognitive Disorders Following Cardiac Surgery? A Systematic Review and Meta-Analysis With Trial Sequential Analysis of Randomized Controlled Trials

Background: To assess the effect of dexmedetomidine on the reducing risk of perioperative neurocognitive disorders (PNDs) following cardiac surgery.

Methods: A systematic review and meta-analysis with trial sequential analysis (TSA) of randomized controlled trials were performed. PubMed, Embase, Cochrane Library, and CNKI databases (to August 16, 2020) were searched for relevant articles to analyze the incidence of PND for intraoperative or postoperative dexmedetomidine administration after cardiac surgery. PND included postoperative cognitive dysfunction (POCD) and postoperative delirium (POD).

Results: A total of 24 studies with 3,610 patients were included. Compared with the control group, the incidence of POD in the dexmedetomidine group was significantly lower (odds ratio [OR]: 0.59, 95% CI: 0.43–0.82, P = 0.001), with firm evidence from TSA. Subgroup analyses confirmed that dexmedetomidine reduced the incidence of POD with firm evidence following coronary artery bypass grafting surgery (OR: 0.45, 95% CI: 0.26–0.79, P = 0.005), and intervention during the postoperative period (OR: 0.48, 95% CI: 0.34–0.67, P < 0.001). Furthermore, the incidence of POD in the dexmedetomidine group was also decreased in mixed cardiac surgery (OR: 0.68, 95% CI: 0.47–0.98, P = 0.039). Irrespective of whether “Confusion Assessment Method/Confusion Assessment Method for intensive care unit” or “other tools” were used as diagnostic tools, the results showed a decreased risk of POD in the dexmedetomidine group. There was no significant difference in the incidence of POCD (OR: 0.47, 95% CI: 0.22–1.03, P = 0.060) between the two groups, but this result lacked firm evidence from TSA.

Conclusion: The administration of dexmedetomidine during the perioperative period reduced the incidence of POD in patients after cardiac surgery, but there was no significant benefit in the incidence of POCD. The effect of dexmedetomidine on the incidence of POD or POCD following different types of surgery and the optimal dose and timing of dexmedetomidine warrant further investigation.

Trial registration: PROSPERO registration number: CRD42020203980. Registered on September 13, 2020.

Conversion between Mini-Mental State Examination and Montreal Cognitive Assessment scores in older adults undergoing selective surgery using Rasch analysis

AIMS

To develop and validate a conversion table between the MMSE and the MoCA using Rasch analysis in older adults undergoing selective surgery and examine its diagnostic accuracy in detecting cognitive impairment.

DESIGN

Cross-sectional study.

METHODS

Older patients [N = 129; age 66.0 (4.6) years, education 7.7 (3.5) years] undergoing elective surgery were recruited from December 2017 to June 2018. All participants completed the MMSE and MoCA and 113 of them completed a battery of neuropsychological tests. Common person linking based on Rasch analysis was performed to develop the conversion table. The conversions were validated by calculating the intraclass correlation coefficient (ICC), score differences between actual and converted scores, and root mean squared error of the difference (RMSE). The diagnostic accuracy of the conversions for detecting cognitive impairment was also tested.

RESULTS

The MoCA [person measure: 1.3 (1.1) logits] was better targeted to the patients than the MMSE [person measure: 3.2 (1.3) logits]. Conversion from MoCA to MMSE scores (ICC 0.84, 95% CI 0.77-0.88; RMSE 1.36) was more precise than conversion from MMSE to MoCA (ICC 0.82, 95% CI 0.75-0.87; RMSE 2.56). Conversion from MoCA to MMSE demonstrated better diagnostic accuracy in detecting cognitive impairment than the actual MMSE, whereas conversion from MMSE to MoCA exhibited the opposite pattern.

CONCLUSION

Conversion from MoCA to MMSE was more precise and had better diagnostic accuracy in detecting pre-operative cognitive impairment in older patients undergoing selective surgery than conversion from MMSE into MoCA.

IMPACT

The finding is useful for interpreting, comparing, and integrating cognitive measurements in surgical settings and clinical research. Statistically sound conversion between MoCA and MMSE based on Rasch analysis is now possible for surgical setting and clinical research.