Poor Performance on a Preoperative Cognitive Screening Test Predicts Postoperative Complications in Older Orthopedic Surgical Patients

Neuroanesthesiology Update

This review summarizes the literature published in 2020 that is relevant to the perioperative care of neurosurgical patients and patients with neurological diseases as well as critically ill patients with neurological diseases. Broad topics include general perioperative neuroscientific considerations, stroke, traumatic brain injury, monitoring, anesthetic neurotoxicity, and perioperative disorders of cognitive function.

Perioperative Multidisciplinary Delirium Prevention: A Longitudinal Case Report

Postoperative delirium is associated with accelerated cognitive decline, mortality, and high health care costs. The importance of perioperative risk identification is increasingly recognized but optimal prevention strategies are still evolving. We review the case of an at-risk 79-year-old who had 3 lumbar spine surgeries within a year, 2 of which were complicated by postoperative delirium and one which was not. We discuss how a comprehensive preoperative cognitive assessment successfully informed perioperative decision making, including anesthetic management and postoperative multimodal delirium prevention strategies by geriatric medicine. The case exemplifies how coordinated interdisciplinary team management may reduce postoperative delirium in high-risk individuals.

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.

Propofol Requirement and EEG Alpha Band Power During General Anesthesia Provide Complementary Views on Preoperative Cognitive Decline

Background: Although cognitive decline (CD) is associated with increased post-operative morbidity and mortality, routinely screening patients remains difficult. The main objective of this prospective study is to use the EEG response to a Propofol-based general anesthesia (GA) to reveal CD.

Methods: 42 patients with collected EEG and Propofol target concentration infusion (TCI) during GA had a preoperative cognitive assessment using MoCA. We evaluated the performance of three variables to detect CD (MoCA < 25 points): age, Propofol requirement to induce unconsciousness (TCI at SEF₉₅: 8–13 Hz) and the frontal alpha band power (AP at SEF₉₅: 8–13 Hz).

Results: The 17 patients (40%) with CD were significantly older (p < 0.001), had lower TCI (p < 0.001), and AP (p < 0.001). We found using logistic models that TCI and AP were the best set of variables associated with CD (AUC: 0.89) and performed better than age (p < 0.05). Propofol TCI had a greater impact on CD probability compared to AP, although both were complementary in detecting CD.

Conclusion: TCI and AP contribute additively to reveal patient with preoperative cognitive decline. Further research on post-operative cognitive trajectory are necessary to confirm the interest of intra operative variables in addition or as a substitute to cognitive evaluation.

Preoperative assessment and optimization of cognitive dysfunction and frailty in the ambulatory surgical patient

PURPOSE OF REVIEW

The number and the complexity of procedures taking place at ambulatory surgery centers is steadily increasing. The rate at which medically complex patients, including those with baseline neurocognitive disorders, are undergoing ambulatory procedures is seeing a concurrent rise. Given the significant physical and psychological stress associated with surgery even in the ambulatory setting, it is essential to evaluate the ability of a patient to acclimate to stressful triggers in order to assess risk of subpar medical outcomes and increased mortality. In this review, we discuss recent advances in the assessment of both cognition and frailty and describe the implementation of these tools in the ambulatory surgery setting.

RECENT FINDINGS

Recent Society for Perioperative Assessment and Quality Improvement (SPAQI) recommendations for evaluating at-risk patients focus on a two-pronged approach that encompasses screening for both impaired cognition and frailty. Screening should ideally occur as early as possible, but tools such as the Mini-Cog examination and FRAIL Questionnaire are efficient and effective even when used the day of surgery in high-risk patients.

SUMMARY

The recognition of at-risk patients using standardized screening and the use of this assessment to guide perioperative monitoring and interventions is essential for optimizing outcomes for the complex ambulatory surgery patient.

Brief Preoperative Screening for Frailty and Cognitive Impairment Predicts Delirium after Spine Surgery

BACKGROUND

Frailty and cognitive impairment are associated with postoperative delirium, but are rarely assessed preoperatively. The study was designed to test the hypothesis that preoperative screening for frailty or cognitive impairment identifies patients at risk for postoperative delirium (primary outcome).

METHODS

In this prospective cohort study, the authors administered frailty and cognitive screening instruments to 229 patients greater than or equal to 70 yr old presenting for elective spine surgery. Screening for frailty (five-item FRAIL scale [measuring fatigue, resistance, ambulation, illness, and weight loss]) and cognition (Mini-Cog, Animal Verbal Fluency) were performed at the time of the preoperative evaluation. Demographic data, perioperative variables, and postoperative outcomes were gathered. Delirium was the primary outcome detected by either the Confusion Assessment Method, assessed daily from postoperative day 1 to 3 or until discharge, if patient was discharged sooner, or comprehensive chart review. Secondary outcomes were all other-cause complications, discharge not to home, and hospital length of stay.

RESULTS

The cohort was 75 [73 to 79 yr] years of age, 124 of 219 (57%) were male. Many scored positive for prefrailty (117 of 218; 54%), frailty (53 of 218; 24%), and cognitive impairment (50 to 82 of 219; 23 to 37%). Fifty-five patients (25%) developed delirium postoperatively. On multivariable analysis, frailty (scores 3 to 5 [odds ratio, 6.6; 95% CI, 1.96 to 21.9; P = 0.002]) versus robust (score 0) on the FRAIL scale, lower animal fluency scores (odds ratio, 1.08; 95% CI, 1.01 to 1.51; P = 0.036) for each point decrease in the number of animals named, and more invasive surgical procedures (odds ratio, 2.69; 95% CI, 1.31 to 5.50; P = 0.007) versus less invasive procedures were associated with postoperative delirium.

CONCLUSIONS

Screening for frailty and cognitive impairment preoperatively using the FRAIL scale and the Animal Verbal Fluency test in older elective spine surgery patients identifies those at high risk for the development of postoperative delirium.

EDITOR’S PERSPECTIVE

Executive Function, Dexterity, and Discharge Disposition in Older Intensive Care Unit Survivors

BACKGROUND

Dexterity is a component of motor function. Executive function, a subdomain of cognition, may affect dexterity in older adults recovering from critical illness after discharge from an intensive care unit (ICU).

OBJECTIVES

To explore associations between executive function (attention and cognitive flexibility) and dexterity (fine motor coordination) in the early post-ICU period and examine dexterity by acuity of discharge disposition.

METHODS

The study involved 30 older adults who were functionally independent before hospitalization, underwent mechanical ventilation in the ICU, and had been discharged from the ICU 24 to 48 hours previously. Dexterity was evaluated with the National Institutes of Health Toolbox (NIHTB) Motor Battery 9-Hole Pegboard Dexterity Test (PDT); attention, with the NIHTB Cognition Battery Flanker Inhibitory Control and Attention Test (FICAT); and cognitive flexibility, with the NIHTB Cognition Battery Dimensional Change Card Sort Test (DCCST). Exploratory regression was used to examine associations between executive function and dexterity (fully corrected T scores). Independent-samples t tests were used to compare dexterity between participants discharged home and those discharged to a facility.

RESULTS

FICAT (β = 0.375, P = .03) and DCCST (β = 0.698, P = .001) scores were independently and positively associated with PDT scores. Further, PDT scores were worse among participants discharged to a facility than among those discharged home (mean [SD], 26.71 [6.14] vs 36.33 [10.30]; t24 = 3.003; P = .006).

CONCLUSIONS

Poor executive function is associated with worse dexterity; thus, dexterity may be a correlate of both post-ICU cognitive impairment and functional decline. Performance on dexterity tests could identify frail older ICU survivors at risk for worse discharge outcomes.

Electroencephalogram Burst-suppression during Cardiopulmonary Bypass in Elderly Patients Mediates Postoperative Delirium

BACKGROUND

Intraoperative burst-suppression is associated with postoperative delirium. Whether this association is causal remains unclear. Therefore, the authors investigated whether burst-suppression during cardiopulmonary bypass (CPB) mediates the effects of known delirium risk factors on postoperative delirium.

METHODS

This was a retrospective cohort observational substudy of the Minimizing ICU [intensive care unit] Neurological Dysfunction with Dexmedetomidine-induced Sleep (MINDDS) trial. The authors analyzed data from patients more than 60 yr old undergoing cardiac surgery (n = 159). Univariate and multivariable regression analyses were performed to assess for associations and enable causal inference. Delirium risk factors were evaluated using the abbreviated Montreal Cognitive Assessment and Patient-Reported Outcomes Measurement Information System questionnaires for applied cognition, physical function, global health, sleep, and pain. The authors also analyzed electroencephalogram data (n = 141).

RESULTS

The incidence of delirium in patients with CPB burst-suppression was 25% (15 of 60) compared with 6% (5 of 81) in patients without CPB burst-suppression. In univariate analyses, age (odds ratio, 1.08 [95% CI, 1.03 to 1.14]; P = 0.002), lowest CPB temperature (odds ratio, 0.79 [0.66 to 0.94]; P = 0.010), alpha power (odds ratio, 0.65 [0.54 to 0.80]; P < 0.001), and physical function (odds ratio, 0.95 [0.91 to 0.98]; P = 0.007) were associated with CPB burst-suppression. In separate univariate analyses, age (odds ratio, 1.09 [1.02 to 1.16]; P = 0.009), abbreviated Montreal Cognitive Assessment (odds ratio, 0.80 [0.66 to 0.97]; P = 0.024), alpha power (odds ratio, 0.75 [0.59 to 0.96]; P = 0.025), and CPB burst-suppression (odds ratio, 3.79 [1.5 to 9.6]; P = 0.005) were associated with delirium. However, only physical function (odds ratio, 0.96 [0.91 to 0.99]; P = 0.044), lowest CPB temperature (odds ratio, 0.73 [0.58 to 0.88]; P = 0.003), and electroencephalogram alpha power (odds ratio, 0.61 [0.47 to 0.76]; P < 0.001) were retained as predictors in the burst-suppression multivariable model. Burst-suppression (odds ratio, 4.1 [1.5 to 13.7]; P = 0.012) and age (odds ratio, 1.07 [0.99 to 1.15]; P = 0.090) were retained as predictors in the delirium multivariable model. Delirium was associated with decreased electroencephalogram power from 6.8 to 24.4 Hertz.

CONCLUSIONS

The inference from the present study is that CPB burst-suppression mediates the effects of physical function, lowest CPB temperature, and electroencephalogram alpha power on delirium.

Abnormal preoperative cognitive screening in aged surgical patients: a retrospective cohort analysis

BACKGROUND

Preoperative cognitive dysfunction has been associated with adverse postoperative outcomes. There are limited data characterising the epidemiology of preoperative cognitive dysfunction in older surgical patients.

METHODS

This retrospective cohort included all patients ≥65 yr old seen at the Washington University preoperative clinic between January 2013 and June 2018. Cognitive screening was performed using the Short-Blessed Test (SBT) and Eight-Item Interview to Differentiate Aging and Dementia (AD8) screen. The primary outcome of abnormal cognitive screening was defined as SBT score ≥5 or AD8 score ≥2. Multivariable logistic regression was used to identify associated factors.

RESULTS

Overall, 21 666 patients ≥65 yr old completed screening during the study period; 23.5% (n=5099) of cognitive screens were abnormal. Abnormal cognitive screening was associated with increasing age, decreasing BMI, male sex, non-Caucasian race, decreased functional independence, and decreased metabolic functional capacity. Patients with a history of stroke or transient ischaemic attack, chronic obstructive pulmonary disease, diabetes mellitus, hepatic cirrhosis, and heavy alcohol use were also more likely to have an abnormal cognitive screen. Predictive modelling showed no combination of patient factors was able to reliably identify patients who had a <10% probability of abnormal cognitive screening.

CONCLUSIONS

Routine preoperative cognitive screening of unselected aged surgical patients often revealed deficits consistent with cognitive impairment or dementia. Such deficits were associated with increased age, decreased function, decreased BMI, and several common medical comorbidities. Further research is necessary to characterise the clinical implications of preoperative cognitive dysfunction and identify interventions that may reduce related postoperative complications.

American Society for Enhanced Recovery and Perioperative Quality Initiative Joint Consensus Statement on Postoperative Delirium Prevention

Postoperative delirium is a geriatric syndrome that manifests as changes in cognition, attention, and levels of consciousness after surgery. It occurs in up to 50% of patients after major surgery and is associated with adverse outcomes, including increased hospital length of stay, higher cost of care, higher rates of institutionalization after discharge, and higher rates of readmission. Furthermore, it is associated with functional decline and cognitive impairments after surgery. As the age and medical complexity of our surgical population increases, practitioners need the skills to identify and prevent delirium in this high-risk population. Because delirium is a common and consequential postoperative complication, there has been an abundance of recent research focused on delirium, conducted by clinicians from a variety of specialties. There have also been several reviews and recommendation statements; however, these have not been based on robust evidence. The Sixth Perioperative Quality Initiative (POQI-6) consensus conference brought together a team of multidisciplinary experts to formally survey and evaluate the literature on postoperative delirium prevention and provide evidence-based recommendations using an iterative Delphi process and Grading of Recommendations Assessment, Development and Evaluation (GRADE) Criteria for evaluating biomedical literature.

Peri-operative management of frailty in the orthopedic patient

The purpose of this investigation was to summarize current research on diagnosis, outcomes, and management of frail patients undergoing orthopedic surgery. Because frail patients are at increased risk of negative post-operative outcomes including increased 30-day mortality and post-operative complications including infections and delirium, such a review is timely. Strategies including supervised exercise training programs before surgery, early identification of frailty, prophylactic antibiotics, regular drug chart review, regular monitoring of electrolytes, and other strategies to prevent post-operative delirium are helpful in the management of frail orthopedic patients. It is important for surgeons and anesthesiologists to take action in attempt to alleviate adverse post-operative outcomes in frail patients. Ultimately, more research is needed to identify new strategies and to evaluate whether pre-operative optimization can effectively mitigate post-operative outcomes in large-scale randomized controlled trials.

Preoperative Cognitive Assessment Recommendations for the Older Adult

PURPOSE

The purpose of this project was to identify the need for and to improve the preoperative cognitive assessment of the older adult.

DESIGN

A retrospective chart review was used to explore the incidence of postoperative delirium (PD) and characteristics associated with it.

METHODS

A retrospective chart review was used to identify the incidence of PD in a community hospital. The data were analyzed using descriptive statistics for trends in demographic and physiological characteristics of older adults undergoing elective hip or knee surgery.

FINDINGS

The incidence of PD was found to be 11%. Older adults with PD had an increased mean age and comorbid conditions. PD was associated with a mean increase in hospital stay, postoperative complications, and 30-day readmission.

CONCLUSIONS

Preoperative cognitive assessment can identify high-risk patients, stratify care, medically optimize the older adult before surgery, and improve perioperative outcomes.

The Prevalence and Impact of Undiagnosed Mild Cognitive Impairment in Elderly Patients Undergoing Thoracic Surgery: A Prospective Cohort Study

OBJECTIVES

The objective of this study was to explore the prevalence of undiagnosed mild cognitive impairment (MCI) and its association with adverse outcomes in elderly patients undergoing thoracic surgery.

DESIGN

A prospective cohort study.

SETTING

Large tertiary medical center.

PARTICIPANTS

The authors enrolled 170 patients aged 65 years or older who were scheduled for thoracic surgery between November 7, 2018, and April 1, 2019, at the Shanghai Chest Hospital. Patients with a history of schizophrenia or dementia disease, uncorrected vision or hearing impairment, and refusal to participate were excluded.

INTERVENTIONS

A total of 154 elderly patients completed the Chinese version of the Montreal Cognitive Assessment (MoCA) test preoperatively and were included in the final analysis. They were categorized into a normal group (MoCA ≥ 26 scores, group N) and an abnormal group (MoCA < 26 scores, group AN) based on test results. Delirium was assessed with the Confusion Assessment Method twice daily during the first 3 postoperative days.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was the incidence of postoperative delirium (POD). Secondary outcomes included the incidence of postoperative pulmonary complications (PPCs), cardiovascular complications, other complications, intensive care unit (ICU) stay, and the hospital length of stay (LOS). The incidence of MCI before thoracic surgery in elderly patients was 49.4% (76 of 154). Compared with group N, MCI could increase the incidence of POD (14.1% v 30.3%, p = 0.016) and median LOS (4 d v 5 d, p = 0.016). However, the differences in pulmonary complications, cardiovascular and other complications, and ICU stay were not significant. Multivariable logistic regression analysis showed preoperative MCI (OR = 2.573, 95% CI =1.092 to 6.060, p = 0.031) as an independent risk factor of POD. Compared with the elderly patients without POD, POD could increase the risk of PPCs (17.5% v 35.3%, p = 0.026) and median LOS (4 d v 5 d, p < 0.001).

CONCLUSIONS

The incidence of MCI before thoracic surgery in elderly patients was higher and associated with a higher rate of adverse postoperative outcomes. The findings may be important for preoperative patient counseling, operative planning, and eventually reducing potential risk exposure and related outcomes.

Preoperative Evaluation Before Noncardiac Surgery

The medical complexity of surgical patients is increasing and medical specialties are frequently asked to assist with the perioperative management surgical patients. Effective pre-anesthetic medical evaluations are a valuable tool in providing high-value, patient-centered surgical care and should systematically address risk assessment and identify areas for risk modification. This review outlines a structured approach to the pre-anesthetic medical evaluation, focusing on the asymptomatic patient. It discusses the evidence supporting the use of perioperative risk calculation tools and focused preoperative testing. We also introduce important key topics that will be explored in greater detail in upcoming reviews in this series.

Perioperative Continuous Femoral Nerve Block Reduces Postoperative Cognitive Dysfunction of High-Risk Patients with Femoral Neck Fracture: Evidence from a Retrospective Propensity-Matched Study

BACKGROUND Elderly patients often suffer from postoperative cognitive impairment which increases mortality, morbidity, and the economic burden. However, how continuous femoral nerve block (cFNB) influence the incidence of postoperative cognitive dysfunction (POCD) has never been reported. This study tried to explore how cFNB affects the incidence of POCD among low-risk and high-risk patients with femoral neck fractures. MATERIAL AND METHODS We conducted a retrospective propensity score-matched study and allocated matched patients (n=172) with femoral neck fractures into the cFNB group (n=86) and the control group (n=86). Demographical and clinical data were collected and compared, including the visual analog scale (VAS) score, the morphine consumption, and the POCD incidence. Subgroup analysis of high-risk patients (Mini-Cog score ≤2) and low-risk patients (Mini-Cog score ≥3) was also carried out. RESULTS After matching, baseline characteristics of 2 groups were comparable between the 2 groups (all P>0.05). Compared with the control group, the cFNB group had significantly lower visual analog scale (VAS) score and morphine consumption in the postoperative 3 days (P<0.05). For high-risk patients, the Kaplan-Meier survival curve suggested that the incidence of POCD the cFNB group was significantly lower than the control group (P=0.005), without statistical difference for total or low-risk patients (P>0.05). Multivariate Cox hazard regression analysis showed that the adoption of cFNB conferred a protective effect on POCD (HR=0.556, 95% CI 0.316-0.981, P=0.043). CONCLUSIONS For patients undergoing femoral neck fracture surgery, perioperative cFNB administration is useful in decreasing the incidence of POCD, especially for high-risk patients with a Mini-Cog score equal to or less than 2 points.

Association Between Postoperative Delirium and Long-term Cognitive Function After Major Nonemergent Surgery

Importance

Postoperative delirium is associated with decreases in long-term cognitive function in elderly populations.

Objective

To determine whether postoperative delirium is associated with decreased long-term cognition in a younger, more heterogeneous population.

Design, Setting, and Participants

A prospective cohort study was conducted at a single academic medical center (≥800 beds) in the southeastern United States from September 5, 2017, through January 15, 2018. A total of 191 patients aged 18 years or older who were English-speaking and were anticipated to require at least 1 night of hospital admission after a scheduled major nonemergent surgery were included. Prisoners, individuals without baseline cognitive assessments, and those who could not provide informed consent were excluded. Ninety-day follow-up assessments were performed on 135 patients (70.7%).

Exposures

The primary exposure was postoperative delirium defined as any instance of delirium occurring 24 to 72 hours after an operation. Delirium was diagnosed by the research team using the Confusion Assessment Method (CAM).

Main Outcomes and Measures

The primary outcome was change in cognition at 90 days after surgery compared with baseline, preoperative cognition. Cognition was measured using a telephone version of the Montreal Cognitive Assessment (T-MoCA) with cognitive impairment defined as a score less than 18 on a scale of 0 to 22.

Results

Of the 191 patients included in the study, 110 (57.6%) were women; the mean (SD) age was 56.8 (16.7) years. For the primary outcome of interest, patients with and without delirium had a small increase in T-MoCA scores at 90 days compared with baseline on unadjusted analysis (with delirium, 0.69; 95% CI, -0.34 to 1.73 vs without delirium, 0.67; 95% CI, 0.17-1.16). The initial multivariate linear regression model included age, preoperative American Society of Anesthesiologists Physical Status Classification System score, preoperative cognitive impairment, and duration of anesthesia. Preoperative cognitive impairment proved to be the only notable confounder: when adjusted for preoperative cognitive impairment, patients with delirium had a 0.70-point greater decrease in 90-day T-MoCA scores than those without delirium compared with their respective baseline scores (with delirium, 0.16; 95% CI, -0.63 to 0.94 vs without delirium, 0.86; 95% CI, 0.40-1.33).

Conclusions and Relevance

Although a statistically significant association between 90-day cognition and postoperative delirium was not noted, patients with preoperative cognitive impairment appeared to have improvements in cognition 90 days after surgery; however, this finding was attenuated if they became delirious. Preoperative cognitive impairment alone should not preclude patients from undergoing indicated surgical procedures.

Rapid in-person cognitive screening in the preoperative setting: Test considerations and recommendations from the Society for Perioperative Assessment and Quality Improvement (SPAQI)

There are few cognitive screening tools appropriate for fast-paced settings with limited staffing, and particularly in preoperative evaluation clinics. The Society for Perioperative Assessment and Quality Improvement (SPAQI) convened experts in neuropsychology, geriatric medicine, and anesthesiology to conduct a review of the literature and compile a comprehensive list of cognitive screening tools used within primary care and preoperative settings. This Recommendations Statement: 1. summarizes a review of the literature on existing cognitive screening tools used within preoperative settings; 2. discusses factors to consider when selecting cognitive screening tools in a preoperative environment; and 3. includes a work flow diagram to guide use of these screening measures. Methodology involved searching peer-reviewed literature for 29 cognitive screening tools which were identified from the literature that fit inclusion criteria. Of these 29, seven tests have been used in preoperative settings and are discussed. These seven had an average administration time ranging from one to ten minutes. Memory, language, and attention were the most commonly evaluated cognitive domains. Most had adequate sensitivity and specificity to detect cognitive impairment/dementia. While information on the psychometric properties of these tools is limited, the tools discussed are appropriate for lay examiners, are short in duration, and accessible for free or at a low cost. We describe factors that must be considered prior to instrument selection.

Rapid In-Person Cognitive Screening in the Preoperative Setting: Test Considerations and Recommendations from the Society for Perioperative Assessment and Quality Improvement (SPAQI)

There are few cognitive screening tools appropriate for fast-paced settings with limited staffing, and particularly in preoperative evaluation clinics. The Society for Perioperative Assessment and Quality Improvement (SPAQI) convened experts in neuropsychology, geriatric medicine, and anesthesiology to conduct a review of the literature and compile a comprehensive list of cognitive screening tools used within primary care and preoperative settings. This Recommendations Statement: 1. summarizes a review of the literature on existing cognitive screening tools used within preoperative settings; 2. discusses factors to consider when selecting cognitive screening tools in a preoperative environment; and 3. includes a work flow diagram to guide use of these screening measures. Methodology involved searching peer-reviewed literature for 29 cognitive screening tools which were identified from the literature that fit inclusion criteria. Of these 29, seven tests have been used in preoperative settings and are discussed. These seven had an average administration time ranging from one to ten minutes. Memory, language, and attention were the most commonly evaluated cognitive domains. Most had adequate sensitivity and specificity to detect cognitive impairment/dementia. While information on the psychometric properties of these tools is limited, the tools discussed are appropriate for lay examiners, are short in duration, and accessible for free or at a low cost. We describe factors that must be considered prior to instrument selection.

Prevalence and Multivariable Factors Associated With Preoperative Cognitive Impairment in Outpatient Surgery in the United States

Preoperative cognitive impairment increases the risk of adverse events after surgery but its prevalence in outpatient surgery has not been defined. We aimed to determine the prevalence and multivariable factors associated with cognitive impairment in individuals who present for outpatient surgery. We used data from the Health and Retirement Study, a longitudinal panel survey of older Americans. Of 1836 participants who reported having outpatient surgery, we found that 16.1% had evidence of cognitive impairment. Significant multivariable factors associated with preoperative cognitive impairment included non-Hispanic African American race, prior stroke, preoperative functional dependence, and lower socioeconomic status and education level.

A Preoperative Cognitive Screening Test Predicts Increased Length of Stay in a Frail Population: A Retrospective Case-Control Study

BACKGROUND

Frailty is associated with adverse perioperative outcomes including major morbidity, mortality, and increased length of stay. We sought to elucidate the role that a preoperatively assessed Mini-Cog can play in assessing the risk of adverse perioperative outcomes in a population at high risk of frailty.

METHODS

In this retrospective case-control study, patients who were >60 years of age, nonambulatory, or had >5 documented medications were preoperatively assessed for handgrip strength, walking speed, and Mini-Cog score. The Emory University Clinical Data Warehouse was then used to extract this information and other perioperative data elements and outcomes data.

RESULTS

Data were available for 1132 patients undergoing a wide variety of surgical procedures. For the subset of 747 patients with data for observed-to-expected length of stay, an abnormal Mini-Cog was associated with an increased odds of observed-to-expected >1 (odds ratio, 1.52; 95% CI, 1.05-2.19; P = .025). There was no association of abnormal Mini-Cog with intensive care unit length of stay >3 days (P = .182) discharge to home with self-care (P = .873) or risk of readmission (P = .104). Decreased baseline hemoglobin was associated with increased risk of 2 of the 4 outcomes studied.

CONCLUSIONS

In a high-risk pool of patients, Mini-Cog may not be sensitive enough to detect significant differences for most adverse outcomes. Further work is needed to assess whether cognitive screens with greater resolution are of value in this context and to compare tools for assessing overall frailty status.

Retrospective Analysis of Perioperative Variables Associated With Postoperative Delirium and Other Adverse Outcomes in Older Patients After Spine Surgery

BACKGROUND

The aim of this retrospective study was to identify perioperative variables predictive of the development of delirium in older surgical patients after spine surgery.

MATERIALS AND METHODS

We collected preoperative, intraoperative, and postoperative data on patients 65 years of age and above having spine surgery between July 1, 2015 and March 15, 2017. The primary outcome was the development of postoperative delirium. Data were analyzed using univariate and multivariable analysis.

RESULTS

Among the 716 patients included in this study 127 (18%) developed postoperative delirium. On multivariable analysis, independent predictors of postoperative delirium included older age (odds ratio [OR]=1.04; 95% confidence interval [CI], 1.00-1.09; P=0.048), American Society of Anesthesiologists physical status >2 (OR=1.89 [95% CI, 1.04-3.59]; P=0.042), metabolic equivalents of task <4 (OR=1.84 [95% CI, 1.10-3.07]; P=0.019), depression (OR=2.01 [95% CI, 1.21-3.32]; P=0.006), nonelective surgery (OR=4.81 [95% CI, 1.75-12.79]; P=0.002), invasive surgical procedures (OR=1.97 [95% CI, 1.10-3.69]; P=0.028) and higher mean pain scores on postoperative day 1 (OR=1.28 [95% CI, 1.11-1.48]; P<0.001).

CONCLUSIONS

Postoperative delirium is a common complication in older patients after spine surgery, and there are several perioperative risk factors associated with its development.

Feasibility and Rationale for Incorporating Frailty and Cognitive Screening Protocols in a Preoperative Anesthesia Clinic

BACKGROUND

Advanced age, frailty, low education level, and impaired cognition are generally reported to be associated with postoperative cognitive complications. To translate research findings into hospital-wide preoperative assessment clinical practice, we examined the feasibility of implementing a preoperative frailty and cognitive assessment for all older adults electing surgical procedures in a tertiary medical center. We examined associations among age, education, frailty, and comorbidity with the clock and 3-word memory scores, estimated the prevalence of mild to major cognitive impairment in the presurgical sample, and examined factors related to hospital length of stay.

METHODS

Medical staff screened adults ≥65 years of age for frailty, general cognition (via the clock-drawing test command and copy, 3-word memory test), and obtained years of education. Feasibility was studied in 2 phases: (1) a pilot phase involving 4 advanced nurse practitioners and (2) a 2-month implementation phase involving all preoperative staff. We tracked sources of missing data, investigated associations of study variables with measures of cognition, and used 2 approaches to estimate the likelihood of dementia in our sample (ie, using extant data and logistic regression modeling and using Mini-Cog cut scores). We explored which protocol variables related to hospital length of stay.

RESULTS

The final implementation phase sample included 678 patients. Clock and 3-word memory scores were significantly associated with age, frailty, and education. Education, clock scores, and 3-word scores were not significantly different by surgery type. Likelihood of preoperative cognitive impairment was approximately 20%, with no difference by surgery type. Length of stay was significantly associated with preoperative comorbidity and performance on the clock copy condition.

CONCLUSIONS

Frailty and cognitive screening protocols are feasible and provide information for perioperative care planning. Challenges to clinical adaptation include staff training, missing data, and additional administration time. These challenges appear minimal relative to the benefits of identifying frailty and cognitive impairment in a group at risk for negative postoperative cognitive outcome.

The Growing Challenge of the Older Surgical Population

The population of older adults is rapidly growing. With the continued advancement of medical and surgical interventions, the average age of this population will continue to increase. Nearly one-third of surgical procedures are performed in older adults. Physiologic changes, multiple comorbidities, frailty, and postoperative cognitive dysfunction affect an elderly patient's postoperative recovery. Anesthesia providers can play a key role in creating perioperative geriatric pathways. The perioperative care of a geriatric patient is associated with unique and anesthetic risks. Perioperative care must be tailored to individual patients to reduce perioperative complications in this important, vulnerable population.

The older adult with preexisting neurocognitive disorder

PURPOSE OF REVIEW

With the ageing population, there is an increasing number of patients with a neurocognitive disorder (NCD) who undergo surgical procedures. The aim of this review is to highlight the epidemiology of preoperative NCD.

RECENT FINDINGS

New guidelines have defined NCD into mild NCD and major NCD consistent with terminology from the wider clinical community. Several assessment tools have been used in the preoperative setting to identify patients with evidence of cognitive decline. NCD prior to surgery remains a major risk factor postoperative delirium.

SUMMARY

Cognitive dysfunction is common prior to surgery. Awareness of dysfunction, especially when taking care of older adults, is critical given the high risk of complications in this population.

The association of cognitive impairment as screened by the Mini-Cog with long term post-hospitalization outcomes

BACKGROUND

Prior studies have suggested that patients with cognitive impairment are at increased risk for adverse post-hospitalization outcomes. We aimed to determine if cognitive status assessed by the Mini-Cog, a quick bedside screening test, is associated with long-term outcomes.

METHODS

In this secondary analysis of data from a prospective cohort study, 668 patients >65 years of age admitted to a tertiary care academic hospital over a two-year period were screened for cognitive impairment with the Mini-Cog within 24 h of admission. We performed multivariable regression adjusting for demographics, comorbidities, principal diagnoses and functional status to determine association between cognitive impairment and discharge to post-acute care, 90-day readmission and one-year mortality.

RESULTS

Overall 35% screened positive for cognitive impairment. Those with impairment were older (median age 83 versus 78), less likely to be admitted from home and had lower functional independence and self-reported performance scores (p < 0.001 for all). Patients with cognitive impairment were more likely to be discharged to post-acute care facilities (54% versus 39%, p < 0.001). 90-day readmission rate of patients with and without cognitive impairment was 35% versus 27%; one-year survival 77% versus 84% and median length-of-stay was 4 days for both groups. Differences in readmission and mortality were not statistically significant after adjusting for covariates.

CONCLUSION

Cognitive impairment as screened for by the Mini-Cog was not associated with readmission, length-of-stay, or 1-year mortality but was associated with discharge to post-acute care. Other tools such as frailty assessment may be more useful in predicting these outcomes in hospitalized older adults.

Preoperative Assessment of Older Adults

Older patients undergoing surgery have reduced physiologic reserve caused by the combined impact of physiologic age-related changes and the increased burden of comorbid conditions. The preoperative assessment of older patients is directed at evaluating the patient's functional reserve and identifying opportunities to minimize any potential for complications. In addition to a standard preoperative evaluation that includes cardiac risk and a systematic review of systems, the evaluation should be supplemented with a review of geriatric syndromes. Age-based laboratory testing protocols can lead to unnecessary testing, and all testing should be requested if indicated by underlying disease and surgical risk.

Special Considerations for the Aging Brain and Perioperative Neurocognitive Dysfunction

Postoperative delirium and postoperative cognitive dysfunction (POCD) occur commonly in older adults after surgery and are frequently underrecognized. Delirium has been associated with worse outcomes, and both delirium and cognitive dysfunction increase the risk of long-term cognitive decline. Although the pathophysiology of delirium and POCD have not been clearly defined, risk factors for both include increasing age, lower levels of education, and baseline cognitive impairment. In addition, developing delirium increases the risk of POCD. This article examines interventions that may reduce the risk of developing delirium and POCD and improve long-term recovery and outcomes in the vulnerable older population.

Better Brain and Cognition Prior to Surgery Is Associated With Elevated Postoperative Brain Extracellular Free-Water in Older Adults

For adults age 65 and older, the brain shows acute functional connectivity decreases after total knee arthroplasty with the severity of change predicted by preoperative cognitive function and brain disease burden. The extent of acute structural microstructural brain changes acutely after surgery remains unknown within the literature. For the current study, we report on the severity of acute post-surgery microstructural brain changes as measured by diffusion imaging and free-water analysis. Participants who underwent total knee arthroplasty under general anesthesia and non-surgery peers were part of a federally funded prospective cohort investigation involving participants. Recruitment occurred between 2013 and 2017. Data were collected in outpatient and inpatient settings within a university-affiliated medical center. A total of 232 TKA patients were referred by the study surgeon and contacted for study inclusion. Of these, 78 met inclusion and exclusion criteria and completed assessment. Five participants were excluded due to anesthetic protocol changes (spinal instead of general) with an additional 12 excluded for imaging-related complications. The total included sample size was 61. A total of 127 non-surgery participants were screened with 66 enrolled. One non-surgery participant was excluded for an imaging-related complication. Total knee arthroplasty and general anesthetic protocols were standardized. Participants received preoperative neurocognitive assessment and brain magnetic resonance imaging, with repeat imaging 48 h after surgery or pseudo surgery. Free-water analyses were performed using diffusion weighted images and tract-based spatial statistics with baseline cognitive data used to predict free-water changes. Surgery participants had widespread increases in white matter free-water. Surgery participants with higher cognitive functions as measured by immediate memory and less evidence of brain atrophy and disease (i.e., brain integrity) had greater free-water increase. Non-surgery peers had no free-water change. We interpret the surgery group’s free-water change as indicating widespread brain white matter glial response, with greater change indicative of better brain response to the acute surgery/anesthesia experience.

EEG power spectral density under Propofol and its association with burst suppression, a marker of cerebral fragility

OBJECTIVE

Under General Anesthesia (GA), age and Burst Suppression (BS) are associated with cognitive postoperative complications, yet how these parameters are related to per-operative EEG and hypnotic doses is unclear. In this prospective study, we address this question comparing age and BS occurrences with a new score (BP_TIVA) based on Propofol doses, EEG and alpha-band power spectral densities, evaluated for SEF₉₅ = 8-13 Hz.

METHODS

59 patients (55 [34-67] yr, 67% female) undergoing neuroradiology or orthopedic surgery were included. Total IntraVenous Anesthesia was used for Propofol and analgesics infusion. Cerebral activity was monitored from a frontal electrodes montage EEG.

RESULTS

BP_TIVA was inversely correlated with age (Pearson r = -0.78, p < 0.001), and was significantly lower (p < 0.001) when BS occurred during the GA first minutes (induction). Additionally, the age-free BP_TIVA score was better associated with BS at induction than age (AUC = 0.94 versus 0.82, p < 0.05).

CONCLUSION

We designed BP_TIVA score based on hypnotics and EEG. It was correlated with age yet was better associated to BS occurring during GA induction, the latter being a cerebral fragility sign.

SIGNIFICANCE

This advocate for an approach based on evaluating the cerebral physiological age («brain age») to predict postoperative cognitive evolution.

Clinical predictors of postoperative delirium, functional status, and mortality in geriatric patients undergoing non-elective surgery for hip fracture

STUDY OBJECTIVE

To identify modifiable preoperative factors that might influence the morbidity and mortality associated with non-elective, inpatient hip fracture surgeries in the geriatric surgical population.

DESIGN

Retrospective database analysis from the American College of Surgeons National Surgical Quality Improvement Program Geriatric Surgery Pilot Project.

SETTING

Inpatient, perioperative.

PATIENTS

Geriatric patients undergoing surgery.

INTERVENTIONS

Non-elective hip repair surgery.

MEASUREMENTS

Preoperative demographic, medical, surgical, and anesthetic variables; post-operative rates of delirium, decline in functional status, and 30-day mortality.

MAIN RESULTS

The 1261 patients in this study were predominantly female (74%), white (89%), and non-Hispanic (92%). Ages were distributed across groups from 65 to over 90 years. Most patients were categorized as American Society of Anesthesiologists Physical Status class 3 (64%). General anesthesia (57%) was the most common anesthetic, followed by spinal (38%). Preoperative functional status was recorded in 79% as independent in activities of daily living (ADLs). About one third of patients had baseline dementia. Post-operatively, 42% experienced delirium, and most patients required partial or total assistance with ADLs (72% and 12%, respectively). Reoperation was required in 2.8% of cases. Mortality at 30 days was 5.0%. In the multivariable analysis, risk factors associated with post-operative delirium included dementia and lack of competency to sign consent. In the analysis for postoperative decline in functional status, the major risk factor was a history of falls, while emergently performed surgery was protective. The analysis for mortality at thirty days was under-powered.

CONCLUSIONS

Hip fractures remain a major source of morbidity in geriatric patients. Baseline dementia and inability to sign surgical consent are significant risk factors for adverse outcomes after hip fractures and should be considered in the informed consent process. Data from this study and currently ongoing randomized trials will help guide reductions in morbidity and mortality in this population.

Preoperative Sleep Disturbance Exaggerates Surgery-Induced Neuroinflammation and Neuronal Damage in Aged Mice

Postoperative cognitive dysfunction (POCD) is defined as new cognitive impairment (memory impairment and impaired performance) after surgery, especially in aged patients. Sleep disturbance is a common phenomenon before surgery that has been increasingly thought to affect patient recovery. However, little is known about the functional impact of preoperative sleep disturbance on POCD. Here, we showed that tibial fracture surgery induced cognitive deficit and production of proinflammatory cytokines interleukin-6 (IL-6) and IL-1β, along with microglia and astrocyte activation, neuronal damage, and blood-brain barrier (BBB) disruption. Preoperative sleep disturbance enhanced the surgery-induced neuroinflammation, neuronal damage, BBB disruption, and memory impairment 24 h after surgery. Taken together, these results demonstrated that preoperative sleep disturbance aggravated postoperative cognitive function in aged mice and the mechanism may be related to central nervous system (CNS) inflammation and neuronal damage.

Neuropsychological Functioning in Older Adults with Obesity: Implications for Bariatric Surgery

Bariatric surgery is the most effective approach to treating morbid obesity, resulting in decreased morbidity, mortality, and improved quality of life. Research on outcomes has generally been restricted to young and middle-aged adults, despite a growing epidemic of obesity in older adults. The use of bariatric surgery has been limited in older individuals, in part due to concerns that preexisting cognitive dysfunction increases the risk of poor post-surgical outcomes, including cognitive decline. The literature on the relationship between obesity and cognition in older adults is emerging, but fraught by several methodological limitations. While there is insufficient research to determine the nature of cognitive outcomes following bariatric surgery in older adults, the aim of this paper is to review the existing evidence and make the case for further study.

Perioperative cognitive evaluation

PURPOSE OF REVIEW

This article reviews the recent clinical evidence published between January 2017 and June 2018 - related to perioperative cognitive evaluation. Namely, new insights into risk factors, prevention, diagnosis and diagnostic tools and treatment.

RECENT FINDINGS

Several risk factors (preoperative, intraoperative and postoperative) have been found to be associated with the development of postoperative delirium (POD) and/or postoperative cognitive dysfunction (POCD). Short-term and long-term postoperative consequences can be reduced by targeting risk factors, introducing preventive strategies and including frequent cognitive monitoring. Administration of medications such as ketamine, opioids and benzodiazepines are associated with increased cognitive dysfunction. Prevention of POD/POCD starts with creating an environment, which promotes return to preoperative baseline functioning. This includes frequent monitoring of cognitive status, access to rehabilitation and psychological and social supports, and avoiding polypharmacy. In addition, patients should have early access to their sensory aids and maintain normal circadian rhythm. Treatment of POD/POCD has pharmacological and nonpharmacological approaches.

SUMMARY

Clinical evidence on POD/POCD is continuously evolving, which is essential in guiding clinical management to provide the highest quality of clinical care.

Cognitive Impairment Is Associated with Absolute Intraoperative Frontal α-Band Power but Not with Baseline α-Band Power: A Pilot Study

BACKGROUND

Cognitive abilities decline with aging, leading to a higher risk for the development of postoperative delirium or postoperative neurocognitive disorders after general anesthesia. Since frontal α-band power is known to be highly correlated with cognitive function in general, we hypothesized that preoperative cognitive impairment is associated with lower baseline and intraoperative frontal α-band power in older adults.

METHODS

Patients aged ≥65 years undergoing elective surgery were included in this prospective observational study. Cognitive function was assessed on the day before surgery using six age-sensitive cognitive tests. Scores on those tests were entered into a principal component analysis to calculate a composite "g score" of global cognitive ability. Patient groups were dichotomized into a lower cognitive group (LC) reaching the lower 1/3 of "g scores" and a normal cognitive group (NC) consisting of the upper 2/3 of "g scores." Continuous pre- and intraoperative frontal electroencephalograms (EEGs) were recorded. EEG spectra were analyzed at baseline, before start of anesthesia medication, and during a stable intraoperative period. Significant differences in band power between the NC and LC groups were computed by using a frequency domain (δ 0.5-3 Hz, θ 4-7 Hz, α 8-12 Hz, β 13-30 Hz)-based bootstrapping algorithm.

RESULTS

Of 38 included patients (mean age 72 years), 24 patients were in the NC group, and 14 patients had lower cognitive abilities (LC). Intraoperative α-band power was significantly reduced in the LC group compared to the NC group (NC -1.6 [-4.48/1.17] dB vs. LC -6.0 [-9.02/-2.64] dB), and intraoperative α-band power was positively correlated with "g score" (Spearman correlation: r = 0.381; p = 0.018). Baseline EEG power did not show any associations with "g."

CONCLUSIONS

Preoperative cognitive impairment in older adults is associated with intraoperative absolute frontal α-band power, but not baseline α-band power.