Development of a Novel Self-administered Cognitive Assessment Tool and Normative Data for Older Adults

Postoperative Delirium and the Older Adult: Untangling the Confusion

Postoperative delirium is one of the most prevalent postoperative complications, affecting mostly older adults. Its incidence is expected to rise because of surgical advances, shifting demographics, and increased life expectancy. Although an acute alteration in brain function, postoperative delirium is associated with adverse outcomes, including progressive cognitive decline and dementia, that place significant burdens on patients' lives and healthcare systems. This has prompted efforts to understand the mechanisms of postoperative delirium to provide effective prevention and treatment. There are multiple mechanisms involved in the etiology of postoperative delirium that share similarities with the physiological changes associated with the aging brain. In addition, older patients often have multiple comorbidities including increased cognitive impairment that is also implicated in the genesis of delirium. These tangled connections pinpointed a shift toward creation of a holistic model of the pathophysiology of postoperative delirium. Scientific advancements integrating clinical risk factors, possible postoperative delirium biomarkers, genetic features, digital platforms, and other biotechnical and information technological innovations, will become available in the near future. Advances in artificial intelligence, for example, will aggregate cognitive testing platforms with patient-specific postoperative delirium risk stratification studies, panels of serum and cerebrospinal fluid molecules, electroencephalogram signatures, and gut microbiome features, along with the integration of novel polygenetic variants of sleep and cognition. These advances will allow for the enrollment of high-risk patients into prevention programs and help uncover new pharmacologic targets.

Diagnosing delirium in perioperative and intensive care medicine

PURPOSE OF REVIEW

This article reviews the current literature on instruments used for screening and diagnosing delirium in perioperative and intensive care medicine. It summarizes recent findings to guide clinicians and researchers in choosing the most appropriate tools.

RECENT FINDINGS

The incidence of delirium in hospitalized patients ranges from 5% to over 50%, depending on the population of patients studied. Failure to diagnose delirium in a timely manner is associated with serious adverse outcomes, including death and institutionalization. Valid assessment tests are needed for delirium detection, as early identification and treatment of delirium may help to prevent complications. Currently, there are more than 30 available instruments, which have been developed to assist with the screening and diagnosis of delirium. However, these tools vary greatly in sensitivity, specificity, and administration time, and their overabundance challenges the selection of specific tool as well as direct comparisons and interpretation of results across studies.

SUMMARY

Overlooking or misdiagnosing delirium may result in poor patient outcomes. Familiarizing healthcare workers with the variety of delirium assessments and selecting the most appropriate tool to their needs is an important step toward improving awareness and recognition of delirium.

Independent External Validation of a Preoperative Prediction Model for Delirium After Cardiac Surgery: A Prospective Observational Cohort Study

OBJECTIVE

This investigation provided independent external validation of an existing preoperative risk prediction model.

DESIGN

A prospective observational cohort study of patients undergoing cardiac surgery covering the period between April 16, 2018 and January 18, 2022.

SETTING

Two academic hospitals in Switzerland.

PARTICIPANTS

Adult patients (≥60 years of age) who underwent elective cardiac surgery, including coronary artery bypass graft, mitral or aortic valve replacement or repair, and combined procedures.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The primary outcome measure was the incidence of postoperative delirium (POD) in the intensive or intermediate care unit, diagnosed using the Intensive Care Delirium Screening Checklist. The prediction model contained 4 preoperative risk factors to which the following points were assigned: Mini-Mental State Examination (MMSE) score ≤23 received 2 points; MMSE 24-27, Geriatric Depression Scale (GDS) >4, prior stroke and/or transient ischemic attack (TIA), and abnormal serum albumin (≤3.5 or ≥4.5 g/dL) received 1 point each. The missing data were handled using multiple imputation. In total, 348 patients were included in the study. Sixty patients (17.4%) developed POD. For point levels in the prediction model of 0, 1, 2, and ≥3, the cumulative incidence of POD was 12.6%, 22.8%, 25.8%, and 35%, respectively. The validation resulted in a pooled area under the receiver operating characteristics curve of 0.60 (median CI, 0.525-0.679).

CONCLUSIONS

The evaluated predictive model for delirium after cardiac surgery in this patient cohort showed only poor discriminative capacity but fair calibration.

The current state of artificial intelligence-augmented digitized neurocognitive screening test

The cognitive screening test is a brief cognitive examination that could be easily performed in a clinical setting. However, one of the main drawbacks of this test was that only a paper-based version was available, which restricts the test to be manually administered and graded by medical personnel at the health centers. The main solution to these problems was to develop a potential remote assessment for screening individuals with cognitive impairment. Currently, multiple studies have been adopting artificial intelligence (AI) technology into these tests, evolving the conventional paper-based neurocognitive test into a digitized AI-assisted neurocognitive test. These studies provided credible evidence of the potential of AI-augmented cognitive screening tests to be better and provided the framework for future studies to further improve the implementation of AI technology in the cognitive screening test. The objective of this review article is to discuss different types of AI used in digitized cognitive screening tests and their advantages and disadvantages.

Touchscreen Cognitive Tools for Mild Cognitive Impairment and Dementia Used in Primary Care Across Diverse Cultural and Literacy Populations: A Systematic Review

BACKGROUND

Touchscreen cognitive tools opened new promising opportunities for the early detection of cognitive impairment; however, most research studies are conducted in English-speaking populations and high-income countries, with a gap in knowledge about their use in populations with cultural, linguistic, and educational diversity.

OBJECTIVE

To review the touchscreen tools used in primary care settings for the cognitive assessment of mild cognitive impairment (MCI) and dementia, with a focus on populations of different cultures, languages, and literacy.

METHODS

This systematic review was conducted following the PRISMA guidelines. Studies were identified by searching across MEDLINE, EMBASE, EBSCO, OVID, SCOPUS, SCIELO, LILACS, and by cross-referencing. All studies that provide a first-level cognitive assessment for MCI and dementia with any touchscreen tools suitable to be used in the context of primary care were included.

RESULTS

Forty-two studies reporting on 30 tools and batteries were identified. Substantial differences among the tools emerged, in terms of theoretical framework, clinical validity, and features related to the application in clinical practice. A small proportion of the tools are available in multiple languages. Only 7 out of the 30 tools have a multiple languages validation. Only two tools are validated in low-educated samples, e.g., IDEA and mSTS-MCI.

CONCLUSION

General practitioners can benefit from touchscreen cognitive tools. However, easy requirements of the device, low dependence on the examiner, fast administration, and adaptation to different cultures and languages are some of the main features that we need to take into consideration when implementing touchscreen cognitive tools in the culture and language of underrepresented populations.

Effects of Atipamezole Preconditioning on Cognitive Function and Protein Expression in Related Brain Regions of Aged Rats after General Anesthesia

To explore the possible mechanism of atipamezole in improving cognitive function after general anesthesia in aged rats, forty-five aged SD rats were separated into control, model, and atipamezole groups. Rats in the model group were anesthetized by intraperitoneal injection of 75 mg/kg ketamine plus 5 mg/kg midazolam. Results showed that the escape incubation period of the atipamezole group versus model group on the 2nd, 3rd, and 4th days was shortened, residence time of platform quadrant was prolonged on the 5th day, and number of times of crossing platform quadrant was increased. Compared with the control group, the residence time in the central region of the model group was shortened on the 1st, 2nd, and 3rd days. Atipamezole group's central residence time was prolonged on the 1st, 2nd, and 3rd days compared to the model group. Concentrations of IL-1, IL-6, and TNF-α in the hippocampus of the atipamezole group decreased significantly compared to the model group. The expressions of p-CREB and c-fos proteins in the prefrontal cortex and nucleus accumbens of rats in the atimezazole group were higher than those in the model group. In conclusion, atipamezole preconditioning can reduce cognitive dysfunction in aged rats after general anesthesia, and its mechanism may be related to inhibiting hippocampal inflammatory reaction and improving protein expression levels of p-CREB and c-fos in related brain regions of aged rats.

Digital clock drawing test metrics in older patients before and after endoscopy with sedation: An exploratory analysis

BACKGROUND

In the postoperative period, clinically feasible instruments to monitor elderly patients' neurocognitive recovery and discharge-readiness, especially after short-stay procedures, are limited. Cognitive monitoring may be improved by a novel digital clock drawing test (dCDT). We screened for cognitive impairment with the 4 A Test (4AT) and then administered the dCDT pre and post short-stay procedure (endoscopy). The primary aim was to investigate whether the dCDT was sensitive to a change in cognitive status postendoscopy. We also investigated if preoperative cognitive status impacted postendoscopy dCDT variables.

METHODS

We recruited 100 patients ≥65 years presenting for endoscopy day procedures at a single metropolitan hospital. Participants were assessed after admission and immediately before discharge from the hospital. We administered the 4AT, followed by both command and copy clock conditions of the dCDT. We analysed the total drawing time (dCDT time), as well as scored the drawn clock against the established Montreal Cognitive Assessment (MoCA) criteria both before and after endoscopy.

RESULTS

Linear regression showed higher 4AT test scores (poorer performance) were associated with longer postoperative dCDT time (β = 5.6, p = 0.012) for the command condition after adjusting for preoperative baseline dCDT metrics, sex, age, and years of education.

CONCLUSION

Postoperative dCDT time-based variables slowed in those with baseline cognitive impairment detected by the 4AT, but not for those without cognitive impairment. Our results suggest the dCDT, using the command mode, may help detect cognitive impairment in patients aged >65 years after elective endoscopy.

Testing a Novel Web-Based Neurocognitive Battery in the General Community: Validation and Usability Study

BACKGROUND

In recent years, there has been increased interest in the development of remote psychological assessments. These platforms increase accessibility and allow clinicians to monitor important health metrics, thereby informing patient-centered treatment.

OBJECTIVE

In this study, we report the properties and usability of a new web-based neurocognitive assessment battery and present a normative data set for future use.

METHODS

A total of 781 participants completed a portion of 8 tasks that captured performance in auditory processing, visual-spatial working memory, visual-spatial learning, cognitive flexibility, and emotional processing. A subset of individuals (n=195) completed a 5-question survey measuring the acceptability of the tasks.

RESULTS

Between 252 and 426 participants completed each task. Younger individuals outperformed their older counterparts in 6 of the 8 tasks. Therefore, central tendency data metrics were presented using 7 different age bins. The broad majority of participants found the tasks interesting and enjoyable and endorsed some interest in playing them at home. Only 1 of 195 individuals endorsed not at all for the statement, "I understood the instructions." Older individuals were less likely to understand the instructions; however, 72% (49/68) of individuals over the age of 60 years still felt that they mostly or very much understood the instructions.

CONCLUSIONS

Overall, the tasks were found to be widely acceptable to the participants. The use of web-based neurocognitive tasks such as these may increase the ability to deploy precise data-informed interventions to a wider population.

A novel digital clock drawing test as a screening tool for perioperative neurocognitive disorders: A feasibility study

BACKGROUND

We developed a digital clock drawing test (dCDT), an adaptation of the original pen and paper clock test, that may be advantageous over previous dCDTs in the perioperative environment. We trialed our dCDT on a tablet device in the preoperative period to determine the feasibility of administration in this setting. To assess the clinical utility of this test, we examined the relationship between the performance on the test and compared derived digital clock measures with the 4 A's Test (4AT), a delirium and cognition screening tool.

METHODS

We recruited a sample of 102 adults aged 65 years and over presenting for elective surgery in a single tertiary hospital. Participants completed the 4AT, followed by both command and copy clock conditions of the dCDT. We recorded time-based clock-drawing metrics, alongside clock replications scored using the Montreal Cognitive Assessment (MoCA) clock scoring criteria.

RESULTS

The dCDT had an acceptance rate of 99%. After controlling for demographic variables and prior tablet use, regression analyses showed higher 4AT scores were associated with greater dCDT time (seconds) for both command (β = 8.2, P = .020) and copy clocks (β = 12, P = .005) and lower MoCA-based clock scores in both command (OR = 0.19, P = .001) and copy conditions (OR = 0.14, P = .012).

CONCLUSION

The digital clock drawing test is feasible to administer and is highly acceptable to older adults in a preoperative setting. We demonstrated a significant association between both the dCDT time and clock score metrics, with the established 4AT. Our results provide convergent validity of the dCDT in the preoperative setting.

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.

Neuroanesthesiology Update

This review is intended to provide a summary of the literature pertaining to the perioperative care of neurosurgical patients and patients with neurological diseases. General topics addressed in this review include general neurosurgical considerations, stroke, neurological monitoring, and perioperative disorders of cognitive function.

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.