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Recognition of Delirium Superimposed on Dementia: Is There an Ideal Tool?

Delirium in persons with dementia (DSD) is a common occurrence. Over the past three decades, several tools have been developed and validated to diagnose delirium, yet there is still a shortage of tools recommended in persons with dementia and there is a lack of sufficient research on the accuracy of performance of such tools in this growing population. The purpose of this article is to (1) conduct a clinical review of the detection of DSD across settings of care by formal health care professionals and informal family members and care partners; (2) identify barriers and facilitators to detection and highlight delirium tools that have been tested in person with dementia; and (3) make recommendations for future research, practice, and policy. Given this review, an "ideal" tool for DSD would point to tools being brief, easy to integrate into the EMR, and accurate with at least 90% accuracy given the poor outcomes associated with delirium and DSD. Knowing the baseline and communication between family members and healthcare professionals should be a top priority for education, research, and health systems policy. More work is needed in better understanding DSD and optimizing and standardizing feature assessment, especially the acute change feature at the bedside for DSD.

Prevention of Delirium in Older Adults With Dementia: A Systematic Literature Review

Although dementia is the largest independent risk factor for delirium and leads to poor health outcomes, we know little about how to prevent delirium in persons with dementia (PWD). The purpose of the current systematic literature review was to identify interventions designed to prevent delirium in older PWD. Seven studies meeting inclusion criteria were extracted. Five studies were in the acute care setting and two were community settings. One study used a randomized controlled trial design. Five of the seven interventions comprised multiple components addressing delirium risk factors, including education. Two studies addressed delirium by administration of medication or vitamin supplementation. Using the GRADE framework for the evaluation of study quality, we scored three studies as moderate and four studies as low. Thus, high-quality research studies to guide how best to prevent delirium in PWD are lacking. Although more research is required, the current review suggests that multicomponent approaches addressing delirium risk factors should be considered by health care professionals when supporting older PWD. [Journal of Gerontological Nursing, 46(10), 43-54.].

Complexity in Lipid Membrane Composition Induces Resilience to Aβ42 Aggregation

The molecular origins of Alzheimer's disease are associated with the aggregation of the amyloid-β peptide (Aβ). This process is controlled by a complex cellular homeostasis system, which involves a variety of components, including proteins, metabolites, and lipids. It has been shown in particular that certain components of lipid membranes can speed up Aβ aggregation. This observation prompts the question of whether there are protective cellular mechanisms to counterbalance this effect. Here, to address this issue, we investigate the role of the composition of lipid membranes in modulating the aggregation process of Aβ. By adopting a chemical kinetics approach, we first identify a panel of lipids that affect the aggregation of the 42-residue form of Aβ (Aβ₄₂), ranging from enhancement to inhibition. We then show that these effects tend to average out in mixtures of these lipids, as such mixtures buffer extreme aggregation behaviors as the number of components increases. These results indicate that a degree of quality control on protein aggregation can be achieved through a mechanism by which an increase in the molecular complexity of lipid membranes balances opposite effects and creates resilience to aggregation.

The consistent burden in published estimates of delirium occurrence in medical inpatients over four decades: a systematic review and meta-analysis study

INTRODUCTION

Delirium is associated with a wide range of adverse patient safety outcomes, yet it remains consistently under-diagnosed. We undertook a systematic review of studies describing delirium in adult medical patients in secondary care. We investigated if changes in healthcare complexity were associated with trends in reported delirium over the last four decades.

METHODS

We used identical criteria to a previous systematic review, only including studies using internationally accepted diagnostic criteria for delirium (the Diagnostic and Statistical Manual of Mental Disorders and the International Statistical Classification of Diseases). Estimates were pooled across studies using random effects meta-analysis, and we estimated temporal changes using meta-regression. We investigated publication bias with funnel plots.

RESULTS

We identified 15 further studies to add to 18 studies from the original review. Overall delirium occurrence was 23% (95% CI 19-26%) (33 studies) though this varied according to diagnostic criteria used (highest in DSM-IV, lowest in DSM-5). There was no change from 1980 to 2019, nor was case-mix (average age of sample, proportion with dementia) different. Overall, risk of bias was moderate or low, though there was evidence of increasing publication bias over time.

DISCUSSION

The incidence and prevalence of delirium in hospitals appears to be stable, though publication bias may have masked true changes. Nonetheless, delirium remains a challenging and urgent priority for clinical diagnosis and care pathways.

New Delirium Severity Indicators: Generation and Internal Validation in the Better Assessment of Illness (BASIL) Study

BACKGROUND

Delirium is a common and preventable geriatric syndrome. Moving beyond the binary classification of delirium present/absent, delirium severity represents a potentially important outcome for evaluating preventive and treatment interventions and tracking the course of patients. Although several delirium severity assessment tools currently exist, most have been developed in the absence of advanced measurement methodology and have not been evaluated with rigorous validation studies.

OBJECTIVE

We aimed to report our development of new delirium severity items and the results of item reduction and selection activities guided by psychometric analysis of data derived from a field study.

METHODS

Building on our literature review of delirium instruments and expert panel process to identify domains of delirium severity, we adapted items from existing delirium severity instruments and generated new items. We then fielded these items among a sample of 352 older hospitalized patients.

RESULTS

We used an expert panel process and psychometric data analysis techniques to narrow a set of 303 potential items to 17 items for use in a new delirium severity instrument. The 17-item set demonstrated good internal validity and favorable psychometric characteristics relative to comparator instruments, including the Confusion Assessment Method - Severity (CAM-S) score, the Delirium Rating Scale Revised 98, and the Memorial Delirium Assessment Scale.

CONCLUSION

We more fully conceptualized delirium severity and identified characteristics of an ideal delirium severity instrument. These characteristics include an instrument that is relatively quick to administer, is easy to use by raters with minimal training, and provides a severity rating with good content validity, high internal consistency reliability, and broad domain coverage across delirium symptoms. We anticipate these characteristics to be represented in the subsequent development of our final delirium severity instrument.

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.

Acute and long-term effects of haloperidol on surgery-induced neuroinflammation and cognitive deficits in aged rats

PURPOSE

Neuroinflammation may contribute to the pathogenesis of the cognitive symptoms of postoperative delirium (POD) and its subsequent long-term cognitive impairment. Haloperidol (HAL), a dopamine receptor antagonist, is widely used to treat POD, whereas the effects of HAL on postoperative neuroinflammation and related cognitive deficits have been underdetermined.

METHODS

Aged rats underwent sham or abdominal surgery and were subcutaneously treated with either vehicle, low-dose (0.5 mg/kg bolus, then 0.5 mg/kg/day infusion), or high-dose (2.0 mg/kg bolus, then 2.0 mg/kg/day infusion) HAL. All treatments were initiated immediately after surgery and continued for 48 h. On either postoperative day 2 (early) or 7 (late), all rats were tested for trace and context fear memory retention after acquisition of trace fear conditioning. Following the cognitive testing, the levels of pro-inflammatory cytokines, as well as dopamine and its metabolite, in hippocampus and medial prefrontal cortex (mPFC) were measured.

RESULTS

In the early postoperative period, surgery induced acute neuroinflammation along with related trace and context memory dysfunction. Dopamine turnover was increased in both hippocampus and mPFC, whereas no relationship with memory functions was observed. However, HAL even at high-dose failed to restore the surgery-induced neuroinflammation and related cognitive deficits. In the late postoperative period, chronic neuroinflammation was detected only in hippocampus, which was associated with context, but not trace memory dysfunction. Neither low- nor high-dose HAL could prevent the development of these late-phase neurocognitive deficits.

CONCLUSION

Our findings indicate that perioperative administration with HAL may have no effects on postoperative neuroinflammation and related cognitive impairment.