Screening for Mild Cognitive Impairment in the Preoperative Setting: A Narrative Review

Exploring the Mechanisms of Neuronal Protection by Glial Cell Line-Derived Neurotrophic Factor in Autism Spectrum Disorder

BACKGROUND

A complicated neurological disease known as autism spectrum disorder (ASD) is typified by issues with social interaction, communication, and repetitive behavior. The neural protective mechanisms in ASD are thought to be influenced by genetic variables, including the expression of neurotrophic genes such as glial cell line-derived neurotrophic factor (GDNF).

OBJECTIVE

The aim was to examine the relationship between neuronal protection and cognitive functioning by crosslinking GDNF gene expression and serum levels in individuals with relation to Mini-Mental State Examination (MMSE) scores in ASD patients.

MATERIALS AND METHODS

After getting study approval and informed consent of patients, this case-control study experimental study was conducted for six months between July 2023 and December 2023. The blood samples (5 ml each) were drawn from the study population (n = 140), including 100 ASD patients with a disease course of 30 months based on patients' reports data and 40 healthy controls from four major clinical and hospital settings in Lahore, Karachi, and Bahawalpur from Pakistan. The analytical procedures included nucleic acid extraction, primer design and optimization, and GDNF-targeted real-time quantitative polymerase chain reaction expression analysis. To measure cognitive and behavioral deficits, enzyme-linked immunosorbent assay-based serum GDNF levels (pg/ml) and MMSE scores were compared, concluding the neuronal protection potential of GDNF.

RESULTS

In patients with ASD, lower serum levels of GDNF (9.371 ± 2.388 pg/ml) were linked to more severe behavioral and cognitive deficits confirmed by MMSE scores (13.6 ± 3.5) of ASD patients in comparison with the control group (27.1 ± 2.1). Healthy individuals showed higher relative gene fold expression (11.71) compared to the ASD patients (5.51).

CONCLUSION

There is a notable decrease in GDNF gene expression in people with ASD, which raises the possibility that GDNF is important for both cognitive performance and neuronal protection in these people. GDNF may be a useful biomarker for identifying ASD and comprehending its molecular causes, opening the door for focused treatment approaches.

Effects of dexmedetomidine on renal function, inflammatory markers, and cognitive functioning in elderly patients undergoing hip replacement surgery

OBJECTIVE

To investigate the effects of dexmedetomidine on renal function, inflammatory markers, and cognitive outcome, and to identify factors influencing early postoperative cognitive dysfunction (POCD) in elderly patients undergoing hip replacement surgery.

METHODS

A retrospective analysis was conducted on 162 elderly patients who underwent hip replacement surgery at Cangzhou Central Hospital from March 2022 to May 2023. Patients were divided into a control group (without dexmedetomidine) and an experimental group (with dexmedetomidine). Measurements included creatinine (Cr), blood urea nitrogen (BUN), interleukin 1β (IL-1β), tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), Montreal Cognitive Assessment (MoCA) score, and the incidence of POCD seven days postoperatively. Univariate and logistic regression analyses were employed to investigate the predictors of early POCD.

RESULTS

Significant differences were observed between the groups in terms of renal function, inflammatory markers, and cognitive outcome (Cr, BUN, IL-1β, TNF-α, IL-6 and MoCA scores) (all P<0.05). The experimental group showed a significantly lower incidence of POCD at seven days post-surgery (P<0.05). Logistic regression identified having a neuron-specific enolase (NSE) level seven days post-surgery ≥7.0 pg/ml as a risk factor for early POCD (P=0.001, OR=3.987, 95% CI: 1.789-8.886), whereas intraoperative use of dexmedetomidine was a protective factor (P=0.041, OR=0.424, 95% CI: 0.187-0.964).

CONCLUSION

The use of dexmedetomidine in hip replacement surgery can mitigate postoperative renal injury and inflammatory response, enhance cognitive outcome, and significantly reduce the incidence and risk of early POCD in elderly patients.

Delirium after Cardiac Surgery-A Narrative Review

Postoperative delirium (POD) after cardiac surgery is a well-known phenomenon which carries a higher risk of morbidity and mortality. Multiple patient-specific risk factors and pathophysiologic mechanisms have been identified and therapies have been proposed to mitigate risk of delirium development postoperatively. Notably, cardiac surgery frequently involves the use of an intraoperative cardiopulmonary bypass (CPB), which may contribute to the mechanisms responsible for POD. Despite our greater understanding of these causative factors, a substantial reduction in the incidence of POD remains high among cardiac surgical patients. Multiple therapeutic interventions have been implemented intraoperatively and postoperatively, many with conflicting results. This review article will highlight the incidence and impact of POD in cardiac surgical patients. It will describe some of the primary risk factors associated with POD, as well as anesthetic management and therapies postoperatively that may help to reduce delirium.

Postsurgery Subjective Cognitive and Short-Term Memory Impairment Among Middle-Aged Chinese Patients

Importance

Perioperative neurocognitive disorder, particularly postoperative cognitive impairment, is common and associated with multiple medical and social adversities, although data from China are lacking.

Objective

To examine the incidence, trajectory, and risk factors for subjective cognitive and short-term memory impairment after surgery in the Chinese population.

Design, Setting, and Participants

This cohort study used data from the China Surgery and Anesthesia Cohort to assess surgical patients aged 40 to 65 years from 2 medical centers between July 15, 2020, and March 31, 2023, with active follow-up within 1 year after the surgery. Of 11 158 patients who were successfully recruited (response rate, 94.4%), 10 149 participants were eligible and available for analysis. From this population, separate cohorts were constructed for analyzing subjective cognitive impairment (8105 noncardiac and 678 cardiac surgery patients) and short-term memory impairment (5246 noncardiac and 454 cardiac surgery patients).

Exposures

Twenty-four potential risk factors regarding comorbidities, preoperative psychological conditions, anesthesia- or surgery-related factors, and postsurgical events were included.

Main Outcomes and Measures

Outcomes included subjective cognitive function measured by the 8-Item Informant Interview to Differentiate Aging and Dementia (AD8; scores range from 0 to 8, with higher scores indicating more severe cognitive impairment) and short-term memory measured by the 3-Word Recall Test (TRT; scores range from 0 to 3, with lower scores indicating more severe short-term memory impairment) at 1, 3, 6, and 12 months after noncardiac and cardiac surgery. Generalized linear mixed models were used to identify risk factors associated with the presence of AD8 (score ≥2) or TRT (score <3) abnormality as well as the aggressively deteriorative trajectories of those cognitive measurements.

Results

For noncardiac surgery patients, the AD8 analysis included 8105 patients (mean [SD] age, 52.3 [7.1] years; 3378 [41.7%] male), and the TRT analysis included 5246 patients (mean [SD] age, 51.4 [7.0] years; 1969 [37.5%] male). The AD8 abnormality incidence rates after noncardiac surgery increased from 2.2% (175 of 8105) at 7 days to 17.1% (1059 of 6191) at 6 months after surgery, before appearing to decrease. In contrast, the TRT abnormality incidence rates followed a U-shaped pattern, with the most pronounced incidence rates seen at 7 days (38.9% [2040 of 5246]) and 12 months (49.0% [1394 of 2845]). Similar patterns were seen among cardiac surgery patients for the AD8 analysis (678 patients; mean [SD] age, 53.2 [6.3] years; 393 [58.0%] male) and TRT analysis (454 patients; mean [SD] age, 52.4 [6.4] years; 248 [54.6%] male). Among noncardiac surgery patients, the top risk factors for aggressively deteriorative AD8 trajectory and for AD8 abnormality, respectively, after surgery were preoperative sleep disturbances (Pittsburgh Sleep Quality Index ≥16 vs 0-5: odds ratios [ORs], 4.04 [95% CI, 2.20-7.40] and 4.54 [95% CI, 2.40-8.59]), intensive care unit stay of 2 days or longer (ORs, 2.43 [95% CI, 1.26-4.67] and 3.07 [95% CI, 1.67-5.65]), and preoperative depressive symptoms (ORs, 1.76 [95% CI, 1.38-2.24] and 2.23 [95% CI, 1.79-2.77]). Analyses for TRT abnormality and trajectory, as well as the analyses conducted among cardiac surgery patients, found fewer associated factors.

Conclusions and Relevance

This cohort study of middle-aged Chinese surgery patients found subjective cognitive and short-term memory impairment within 12 months after both cardiac and noncardiac surgery, with multiple identified risk factors, underscoring the potential of preoperative psychological interventions and optimized perioperative management for postoperative cognitive impairment prevention.

"The Big Three" of geriatrics: A review of perioperative cognitive impairment, frailty and malnutrition

Cognitive impairment, frailty, and malnutrition are three of the most impactful pathologies facing an aging population, having dramatic effects on morbidity and mortality across nearly all facets of medical care and intervention. By 2050, the World Health Organization estimates that the population of individuals over the age of sixty worldwide will nearly double, and the public health toll of these demographic changes cannot be understated. With these changing demographics comes a need for a sharpened focus on the care and management of this vulnerable population. The average patient presenting for surgery is getting older, and this necessitates that clinicians understand the implications of these pathologies for both their immediate medical care needs and for appropriate procedural selection and prognostication of surgical outcomes. We believe it is incumbent on clinicians to consider the frailty, nutritional status, and cognitive function of each individual patient when offering a surgical intervention, as well as consider interventions that may delay the progression of these pathologies. Unfortunately, despite excellent evidence supporting things like routine pre-operative frailty screening and nutritional optimization, many interventions that would specifically benefit this population still have not been integrated into routine practice. In this review, we will synthesize the existing literature on these topics to provide a pragmatic approach and understanding for anesthesiologists and intensivists faced with this complex population.

Associations of postoperative delirium with activities of daily living in older people after major surgery: A prospective cohort study

AIMS

To assess the association of postoperative delirium developed in the post-anaesthetic care unit (PACU) with older patients' ability to perform activities of daily living (ADL) during the first five postoperative days.

BACKGROUND

Previous studies have focused on the association between postoperative delirium and long-term function decline, however the association between postoperative delirium and the ability to perform ADL, particularly in the immediate postoperative period, needs further investigation.

DESIGN

A prospective cohort study.

METHODS

A total of 271 older patients who underwent elective or emergency surgery at a tertiary care hospital in Victoria, Australia, participated in the study. Data were collected between July 2021 and December 2021. Delirium was assessed using the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5). The Katz Index of Independence in Activities of Daily Living (KATZ ADL) scale was used to measure ADL. ADL was assessed preoperatively and daily during the first five postoperative days. The STROBE checklist was used to report this study.

RESULTS

Results showed that 44 (16.2%) patients developed new episode of delirium. Postoperative delirium was independently associated with decline in ADL (RR = 2.83, 95% CI = 2.71-2.97; p < 0.001).

CONCLUSIONS

Postoperative delirium was associated with a decline in ADL among older people during the first five postoperative days. Screening for delirium in the PACU is essential to identify delirium during the early stages of postoperative period and implement a timely comprehensive plan.

RELEVANCE TO CLINICAL PRACTICE

Delirium assessment of older patients in the PACU, and for at least the first five postoperative days, is strongly recommended. We also recommend engagement of patients in a focused physical and cognitive daily activity plan, particularly for older patients undergoing major surgery.

PATIENT OR PUBLIC CONTRIBUTION

Patients and nurses helped in data collection at a tertiary care hospital.

Preoperative optimization: Physical and cognitive pre-habilitation and management of chronic medication

Surgery is a significant stressor for older patient. Most are at higher risk of complications due to frailty and comorbidities. This article will review the impact of surgery on the older patient, perioperative risk assessment and stratification, prehabilitation, and specific screenings and interventions. Electronic searches of PubMed were conducted to identify relevant literature using the following search terms: prehabilitation, sarcopenia, osteosarcopenia, frailty, perioperative evaluation, and polypharmacy. Using the frailty phenotype allows for the early identification of geriatric syndromes and potential targets for interventions. However, it does not inform on potential cognitive impairment, which must be assessed separately. Prehabilitation, especially using multimodal interventions, aims to increase functional capacity during the preoperative period in anticipation of the upcoming stress of surgery and the metabolic cost of recovery. It comprises aerobic and resistance training, dietary interventions, psychological interventions, and cessation of adverse health behaviors. Addressing polypharmacy is also important during the perioperative period. Several frailty assessment tools exist, and special tests only take minutes to perform such as the gait speed and chair stand test. Early identification by surgeons leads to early referral to prehabilitation, which needs about four to six weeks to improve function. The decision to enroll patients in a prehabilitation program is based on the understanding of the needs to maintain a structured and personalized intervention taking into consideration the patient's health status, the type of surgery, and the state of the disease. Perioperative evaluation and prehabilitation for older adults are evolving fields, which are generating clinical and scientific interest. This article will review relevant topics to help clinicians adapt usual perioperative care to older patients' particular needs.

Pain Management in the Postoperative Period for People With Dementia: An Integrative Review

Objective

With the increased global prevalence of older people with dementia, more will present for surgery over the coming decades. Therefore, the objective of this study was to synthesize the existing research about how pain in managed for people with dementia in the postoperative period and discuss the implications for clinical practice.

Methods

For this integrative review, the Cumulative Index to Nursing and Allied Health literature, Medline/Pubmed, ProQuest, ERIC, and Health Source Nursing were searched to identify original empirical research published between 2000 and 2021. Tasks were divided between reviewers to ensure independent study selection, data extraction, and risk of bias assessment.

Results

Eleven articles were eligible. The evidence is incompletely developed therefore the review focused on pain assessment, the types and amount of pain relief, that people with dementia receive less analgesia than people without dementia and the challenges for effective pain management. Most studies were surgery for hip fracture so there is scope to look at outcomes for other types of surgery. Analgesia was administered but it was noted that even over a 20-year period, people with dementia received less than cognitively intact people. Pain management could have a stronger evidence-base with more psychometric development of pain assessment tools. Challenges are due to the impaired ability of the person with dementia to communicate pain and that clinicians have difficulty understanding pain behavior in people with dementia.

Conclusion

Adequate pain management for people with dementia in the postoperative period is important for a faster and better recovery.

Prevalence of preoperative cognitive impairment among elderly thoracic surgery patients and association with postoperative delirium: a prospective observational study

Background

Preoperative cognitive impairment (PCI) may increase the incidence of postoperative delirium (POD), yet screening for cognitive impairment is rarely performed. This study hypothesized that Mini-Cog for preoperative cognitive impairment screening predicts postoperative delirium.

Methods

The prospective observational study recruited 153 elderly patients presenting for elective thoracic surgery. Cognitive function of these patients was screened using Mini-Cog preoperatively. We considered that patients with Mini-Cog scores ≤ 3 had cognitive impairment. Delirium was assessed using the Short CAM scale on postoperative days 1-5.

Results

Of the 153 participants, 54 (35.3%) were assigned to the PCI group, and 99 (64.7%) were assigned to the Normal group. Place of residence, education level, and history of hypertension were significantly different between the two groups (P < 0.05). 51 (33.3%) patients developed POD. Multifactorial analysis revealed that PCI (OR = 2.37, P = 0.028), older age (OR = 1.13, P = 0.009), ASA grade III (OR = 2.75, P = 0.012), and longer duration of anesthesia (OR = 1.01, P = 0.007) were associated with POD.

Conclusion

Preoperative cognitive impairment is strongly associated with POD. Mini-Cog could be recommended for screening PCI.

Clinical trial registration

ClinicalTrials.gov, identifier NCT05798767.

Cerebral effects of different prime solutions used during cardiopulmonary bypass

Background

This study aims to compare the cerebral, hemodynamic, and metabolic effects of different prime solutions used in patients undergoing coronary artery bypass grafting.

Methods

Between May 2013 and May 2014, a total of 30 patients (25 males, 5 females; mean age: 59.5±9 years; range, 42 to 78 years) who were schedule for elective isolated coronary artery bypass grafting were included in this prospective study. The patients were randomized into three groups: Group 1 (n=10) (ringer"s lactate [RL]), Group 2 (n=10) (6% hydroxyethyl starch [HES] 130/0.4), and Group 3 (n=10) (RL + 6% HES 130/0.4). Hemodynamic parameters, arterial blood gas analyses, hemoglobin, hematocrit, cerebral regional oxygen saturation, urine output and fluid balance were recorded preoperatively, before and after anesthesia, 10 min after the transition to extracorporeal circulation, while weaning from extracorporeal circulation, and at the end of surgery. Preoperatively and on postoperative Day 5, neuron-specific enolase enzyme and S-100 β protein were assessed. On Day 5 and Week 3 postoperatively, the Standardized Mini-Mental Test was administered to the patients.

Results

The serum neuron-specific enolase enzyme and S-100 β protein levels of the patients were within physiological limits, and there were no clinical findings suggestive of cerebral damage, or changes in the Standardized Mini-Mental Test scores in any of the patients. There was a decrease of more than 20% of the baseline value of cerebral regional oxygen saturation in a total of four patients, one in Group 1 and three in Group 3. No significant difference was observed among the groups in terms of the other parameters.

Conclusion

The prime solution content has no effect on the development of cerebral damage after cardiopulmonary bypass, and the main factor in preventing the development of cerebral damage was the preservation of cerebral perfusion, which can be achieved by monitoring cerebral perfusion in these patients.