Preoperative Cognitive Impairment and Postoperative Delirium in Elderly Surgical Patients: A Retrospective Large Cohort Study (The CIPOD Study)

Supplemental Lidocaine Patches Prior to Percutaneous Nerve Evaluation, a Randomized Trial

IMPORTANCE

Improving patient comfort during percutaneous nerve evaluation (PNE), a trial procedure for sacral neuromodulation, is essential.

OBJECTIVE

The aim of the study was to determine whether the use of a lidocaine patch (LP) prior to PNE procedure improves the pain associated with PNE.

STUDY DESIGN

This double-masked, randomized controlled trial compared a 4% LP to placebo patch (PP) immediately prior to PNE. Female patients ≥18 years of age were included if they were undergoing an office PNE, performed bilaterally and without fluoroscopy, for any indication. Either a lidocaine or placebo patch was placed over the sacrum 30 minutes prior to PNE. Additional local anesthesia with 2% lidocaine without epinephrine was administered per surgeon discretion. All patients received some volume of injectable lidocaine with their procedures. Secondary outcomes included volume of injectable lidocaine used, progression to a permanent implant, amplitude of perineal sensation, and patient satisfaction.

RESULTS

Thirty-nine women were enrolled, with 20 receiving LP and 19 patients receiving PP. Lower 100-mm visual analog scale pain score was seen in the LP group (45 ± 17 with LP vs 61 ± 21 with PP, P = 0.018). This difference was statistically and clinically significantly different between groups. The total injectable lidocaine, patient satisfaction, and progression to permanent implant were similar between groups.

CONCLUSIONS

Patients experienced clinically and statistically significantly less pain at the time of PNE with a preprocedural LP when compared to placebo, despite similar use of local anesthetic. Satisfaction rates were high among all patients.

Preoperative brain volume loss is associated with postoperative delirium in advanced heart failure patients supported by left ventricular assist device

Delirium is a common neurological complication in patients with advanced heart failure (ADHF) following left ventricular assist device (LVAD) implantation, significantly impacting recovery. This study aimed to analyze non-contrast computed tomography (CT) scans of the brain in ADHF patients undergoing LVAD implantation to determine the association between pre-existing brain atrophy and postoperative delirium. A study involving 166 ADHF patients was conducted from March 2020 to July 2023. Non-contrast CT scans were analyzed using advanced quantitative neuroimaging techniques before implantation. The primary marker assessed was the lateral ventricle fraction (LVF), with secondary markers including cortical gray matter fraction (cGMF), white matter fraction (WMF), basal ganglia fraction (BGF), and thalamus fraction (TLF). A total of 56 patients (33%) experienced postoperative delirium within two weeks of implantation. Patients with delirium were older and exhibited greater brain atrophy, indicated by higher LVF and lower cGMF, WMF, BGF, and TLF values. The occurrence of delirium was strongly associated with age, and ventricular enlargement, primarily in the lateral ventricles. LVF effectively predicted delirium development, regardless of age. Preoperative brain volumetric analysis, particularly of the lateral ventricles, may be crucial in identifying patients at risk for postoperative delirium, enhancing postoperative management, and improving outcomes for LVAD recipients.

The effect of toluene sulfonic acid remimazolam on postoperative delirium in elderly patients undergoing painless bronchoscopy

Toluene sulfonic acid remimazolam is a novel benzodiazepine that differs from traditional benzodiazepines (BZDs) due to its rapid onset, swift metabolism, and lack of hepatic or renal metabolism, as well as its reduced effects on cardiac and cerebral functions. Despite its potential advantages, clinical experience with this agent remains limited. This study investigated the effect of remizolam on postoperative delirium in elderly patients undergoing painless bronchoscopy. Among elderly patients undergoing routine painless bronchoscopy examinations, 50 cases were included in the remimazolam group, while the other 50 cases were selected as the propofol group. The primary outcome measured was the incidence of delirium on the first, second, third, fifth, and seventh postoperative days. The secondary outcome was the occurrence of adverse events, including hypotension, hypoxia, physical activity, agitation during recovery, dizziness, and nausea/vomiting during the procedure.This study confirmed that no cases of delirium in the remimazolam group, which also demonstrated a significantly lower incidence of adverse events compared to the propofol group (20% vs. 50%, P < 0.05). The results indicated remimazolam provides effective sedation with minimal adverse reactions and is associated with a lack of complications such as postoperative delirium in elderly patients undergoing painless bronchoscopy.

Relevance of Preoperative Cognitive Impairment for Predicting Postoperative Delirium in Surgical Medicine: A Prospective Cohort Study

BACKGROUND

Post-operative delirium is a dreaded complication after surgery in older patients. The identification of risk factors for delirium and comprehensive geriatric assessment is an extensive part of recent research. However, the preoperative assessment of risk factors, such as impaired cognition, is frequently not standardized.

METHODS

A comprehensive preoperative assessment was performed in 421 surgical patients to investigate the impact of preoperative cognitive impairment (PCI) on the risk of delirium and to evaluate appropriate screening tools (Six-item screener (SIS) and clock-drawing test (CDT)).

RESULTS

Both screening tools showed a significantly increased risk of delirium with p < 0.001 (OR 12.5, 95% [6.42; 24.4]) in SIS and p = 0.042 (OR 2.02, 95%CI [1.02; 4.03]) in CDT for existing cognitive impairment. A higher level of care (p < 0.001) and statutory care (p < 0.001, OR 5.42, 95%CI [2.34; 12.6]) also proved to be significant risk factors. The ROC curves of the two tests show AUC values of 0.741 (SIS) and 0.630 (CDT). The COP values for the SIS are 4 points with a Youden index of 0.447; for the CDT, the COP is 2 (Youden index = 0.177).

CONCLUSIONS

The recording of PCI should be a central component of the preoperative geriatric assessment. The tools used are simple yet effective and can be easily implemented in routine clinical practice. By reliably identifying patients at risk, the available resources can be personalized and used in a targeted approach.

Acute changes in hippocampal metabolism after anesthesia and surgery: Implications for perioperative neurocognitive disorder

BACKGROUND

The risk of developing dementia is higher in individuals who suffer from perioperative neurocognitive disorder (PND), including postoperative cognitive dysfunction (POCD) and delirium. Recent studies have indicated correlations between anesthesia, surgery and PND. Acute metabolic changes induced by anesthesia and surgery may be related to cognitive impairments. Despite a paucity of research on acute metabolic changes in the hippocampus during surgery, there are conflicting about specific metabolites.

METHODS

We developed a mouse model of cognitive impairment induced by isoflurane anesthesia and unilateral nephrectomy. Cognition was evaluated by Y maze and fear conditioning test (FCT). The hippocampus was harvested after the surgery. LC-MS (liquid chromatography-mass spectrometry) was performed. The differential metabolites involved in lipid, amino acid, nucleotide, carbohydrate metabolism were analyzed.

RESULTS

Anesthesia and surgery exposure induced cognition decline. A total of 49 metabolites were significantly up-regulated and 122 down-regulated. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway of the metabolites identified purine, glutathione, nicotinate and nicotinamide metabolism. Metabolites involved in lipid, amino acid, nucleotide, carbohydrate metabolism were identified including nicotinamide adenine dinucleotide (NAD), 1-Methylnicotinamide, propionic acid, histidine, adenosine, and guanosine cyclic monophosphate. Some metabolites exhibited a consistent change trend in the hippocampus of aging mice.

CONCLUSIONS

The study indicates that anesthesia and surgery can induce acute alterations in hippocampal metabolomics, including metabolites involved in lipid, amino acid, nucleotide, and carbohydrate metabolism. These metabolites may play a role in modulating PND through the regulation of neuroinflammation, oxidative stress, blood-brain barrier (BBB) permeability.

Effects of preoperative neoadjuvant chemotherapy on postoperative delirium in patients with gynecological tumor surgery: an observational study

PURPOSE

To investigate whether neoadjuvant chemotherapy (NACT) increases the incidence of postoperative delirium (POD) in patients with gynecological tumors undergoing radical hysterectomy.

METHODS

This study included 60 patients in the neoadjuvant chemotherapy exposure group and 60 in the non-exposure group. Preoperative cognitive function, the incidence of POD and other physiological parameters were assessed on preoperative day 1 (POD-1), postoperative day 1 (POD1), postoperative day 2 (POD2), and postoperative day 3 (POD3). Additionally, preoperative olfactory function was evaluated using an olfactory detection kit on POD-1. The primary outcome was the incidence of POD within three days after surgery.

RESULTS

The incidence of POD was 28.33% in the exposed group and 8.33% in the non-exposed group (P = 0.005). Compared to the non-exposed group, the exposed group had a higher rate of cognitive dysfunction (33.33% vs 13.33%; P = 0.010), and a higher rate of olfactory dysfunction (OD) (25.00% vs 10.00%; P = 0.031). A restricted cubic spline analysis revealed a non-linear relationship between olfactory test scores and Montreal Cognitive Assessment Scale (MoCA) scores (P for overall < 0.001, P for nonlinear = 0.001). Logistic regression identified NACT, mild and moderate cognitive dysfunction, OD, and depression as independent risk factors for POD, with all factors showing significant associations (P < 0.05). The area under the curve (AUC) of OD for predicting POD was 0.783 (95%CI 0.656-0.909).

CONCLUSIONS

This single-blind observational study suggests that NACT increases the incidence of POD in patients with gynecological tumors undergoing radical hysterectomy. Moreover, the results indicate that preoperative OD may reflect preoperative cognitive dysfunction, and have predictive value for the incidence of POD.

Association between Intraoperative Hypotension and Postoperative Delirium: A Retrospective Cohort Analysis

BACKGROUND

Intraoperative hypotension might contribute to the development of postoperative delirium through inadequate cerebral perfusion. However, evidence regarding the association between intraoperative hypotension and postoperative delirium is equivocal. Therefore, the hypothesis that intraoperative hypotension is associated with postoperative delirium in patients older than 70 yr having elective noncardiac surgery was tested .

METHODS

This was a retrospective cohort analysis of patients older than 70 yr who underwent elective noncardiac surgery in a single tertiary academic center between 2020 and 2021. Intraoperative hypotension was quantified as the area under a mean arterial pressure (MAP) threshold of 65 mmHg. Postoperative delirium was defined as a collapsed composite outcome including a positive 4 A's test during the initial 2 postoperative days, and/or delirium identification using the Chart-based Delirium Identification Instrument. The association between hypotension and postoperative delirium was assessed using multivariable logistic regression, adjusting for potential confounding variables. Several sensitivity analyses were performed using similar regression models.

RESULTS

In total, 2,352 patients were included (median age, 76 yr; 1,112 [47%] women; 1,166 [50%] American Society of Anesthesiologists Physical Status III or greater; 698 [31%] having high-risk surgeries). The median [interquartile range] intraoperative area under the curve below a threshold of MAP less than 65 mmHg was 28 [0, 103] mmHg · min. The overall incidence of postoperative delirium was 14% (327 of 2,352). After adjustment for potential confounding variables, hypotension was not associated with postoperative delirium. Compared to the first quartile of area under the curve below a threshold of MAP less than 65 mmHg, patients in the second, third, and fourth quartiles did not have more postoperative delirium, with adjusted odds ratios of 0.94 (95% CI, 0.64 to 1.36; P = 0.73), 0.95 (95% CI, 0.66 to 1.36; P = 0.78), and 0.95 (95% CI, 0.65 to 1.36; P = 0.78), respectively. Intraoperative hypotension was also not associated with postoperative delirium in any of the sensitivity and subgroup analyses performed.

CONCLUSIONS

To the extent of hypotension observed in our cohort, our results suggest that intraoperative hypotension is not associated with postoperative delirium in elderly patients having elective noncardiac surgery.

EDITOR’S PERSPECTIVE

Routine cognitive screening for older people undergoing major elective surgery: Benefits, risks and costs

Cognitive impairment and older age are major risk factors for postoperative delirium. Professional societies have advocated preoperative screening to identify at-risk individuals for implementation of interventions, which have moderate effectiveness in preventing delirium. However, it remains unclear from the guidelines whether screening should be completed routinely for all older individuals or targeted, and also which specific screening tool is preferred. In addition, the responsibility for screening remains undesignated in the guidelines provided. We reviewed the benefits and risks of routine screening. We also performed a cost-benefit analysis of routine screening (versus no screening). Furthermore, we summarised the sensitivities and specificities of commonly used screening tools and reviewed evolving screening tools that may have an increasing role in future practice. We concluded that routine screening is useful and appears to be cost-effective for reducing postoperative delirium, with a cost-benefit ratio of 2.89 (adjusted ratio of 2.34), and has additional advantages over other approaches such as targeted screening or routine intervention.

The Effects of Sevoflurane and Aβ Interaction on CA1 Dendritic Spine Dynamics and MEGF10-Related Astrocytic Synapse Engulfment

General anesthetics may accelerate the neuropathological changes related to Alzheimer's disease (AD), of which amyloid beta (Aβ)-induced toxicity is one of the main causes. However, the interaction of general anesthetics with different Aβ-isoforms remains unclear. In this study, we investigated the effects of sevoflurane (0.4 and 1.2 maximal alveolar concentration (MAC)) on four Aβ species-induced changes on dendritic spine density (DSD) in hippocampal brain slices of Thy1-eGFP mice and multiple epidermal growth factor-like domains 10 (MEGF10)-related astrocyte-mediated synaptic engulfment in hippocampal brain slices of C57BL/6 mice. We found that both sevoflurane and Aβ downregulated CA1-dendritic spines. Moreover, compared with either sevoflurane or Aβ alone, pre-treatment with Aβ isoforms followed by sevoflurane application in general further enhanced spine loss. This enhancement was related to MEGF10-related astrocyte-dependent synaptic engulfment, only in AβpE3 + 1.2 MAC sevoflurane and 3NTyrAβ + 1.2 MAC sevoflurane condition. In addition, removal of sevoflurane alleviated spine loss in Aβ + sevoflurane. In summary, these results suggest that both synapses and astrocytes are sensitive targets for sevoflurane; in the presence of 3NTyrAβ, 1.2 MAC sevoflurane alleviated astrocyte-mediated synaptic engulfment and exerted a lasting effect on dendritic spine remodeling.

A Novel Preoperative Electroencephalogram-Derived Index to Predict Early Postoperative Delirium in Elderly Patients After Hip Fracture Surgeries: Development of a Prediction Model

Introduction

It is appealing to accurately predict postoperative delirium (POD) before surgeries. In this study, it was hypothesized that a novel electroencephalogram-derived index, the delirium index (DELi), could extract latent information regarding the predisposing factors of POD preoperatively. This study was aimed at developing a concise model that incorporated this DELi score to predict the early POD of elderly patients after hip surgeries.

Materials and Methods

Elderly patients scheduled for elective hip fracture surgeries were prospectively enrolled in a tertiary care hospital from November 2020 to June 2022. DELi scores and patient characteristics (age, sex, types of fracture and surgery, the time interval between fracture and surgery, cognitive function assessed using the Montreal Cognitive Assessment (MoCA), and frailty status assessed using the FRAIL scale) were collected preoperatively as candidate predictors. POD diagnosed using the confusion assessment method (CAM) was the outcome. Least absolute shrinkage and selection operator (LASSO) regression analysis was used to select predictors. Then, these predictors were entered into a backward logistical regression analysis to develop a prediction model. Discrimination, calibration and clinical utility were validated using the bootstrapping method.

Results

All data (144 qualified patients of 170) were used for development. POD was observed in 71 patients (49.3%). Preoperative DELi scores predicted early POD (the area under the curve (AUC) = .786, 95% confidence interval (CI): .712, .860, in internal validation). A nomogram with MoCA, FRAIL scale and DELi score was constructed with excellent discrimination (AUC = .920, 95% CI: .876, .963, in internal validation), accredited calibration (P = .733, Hosmer‒Lemeshow test), and a wide range of threshold probabilities (5% to 95%).

Conclusions

Preoperative DELi scores predicted the early POD of elderly patients after hip surgeries. A concise prediction model was developed and demonstrated excellent discrimination.

Preoperative cognitive impairment and postoperative delirium among Holocaust survivors who achieved longevity

BACKGROUND

Holocaust survivors (HS) experience higher rates of physiological and psychological morbidities, increasing their vulnerability to perioperative complications. Limited information exists regarding their perioperative neurocognitive disorders. This study aimed to assess the rates of preoperative cognitive impairment, postoperative delirium, and other complications among HS aged 75+ undergoing elective surgery.

METHODS

This is a single-center retrospective cohort study that analyzed prospectively collected data. All surgical patients born before 1945 who underwent elective noncardiac surgery at a tertiary hospital in Israel during 2020-2021 were included. The HS group was identified through the hospital's information system. Preoperative cognitive impairment was assessed using the Mini-Cog test. Postoperative delirium was defined as a combined outcome, which included a positive 4A's-Test (4AT) result during the postanesthesia care unit stay up to the second postoperative day, a positive 3-Minute Diagnostic Confusion Assessment Method (3D-CAM) test administered by the geriatric team, and identification through the medical records using the Chart-based Delirium Identification Instrument (CHART-DEL). We used multivariable regression to assess the risk factors for postoperative delirium.

RESULTS

Out of 1332 eligible patients, 422 (32%) were HS, while the others served as controls. Both groups had a similar rate of preoperative cognitive impairment (24%, p = 0.89) and postoperative delirium (16%, p = 0.95). HS exhibited a higher risk of the composite adverse events (24% vs. 20%, p = 0.05, aOR [95% CI] 1.3 [1.0-1.7]), driven mainly by falls during hospitalization (4% vs. 2%, p = 0.03, aOR 2.1 [1.1-4.1]). HS patients were more likely to be childless (33% vs. 11%, p = 0.001) and had higher rates of chronic antidepressant and benzodiazepine use.

CONCLUSIONS

HS achieving longevity do not face increased risks of preoperative cognitive impairment and postoperative delirium. However, special care is still warranted due to their elevated rate of other complications during hospitalization.

Association Between Preoperative Sleep Disturbance and Postoperative Delirium in Elderly: A Retrospective Cohort Study

Purpose

Postoperative sleep disturbance, characterized by diminished postoperative sleep quality, is a risk factor for postoperative delirium (POD); however, the association between pre-existing sleep disturbance and POD remains unclear. This study aimed to evaluate the association between preoperative sleep disturbance and POD in elderly patients after non-cardiac surgery.

Patients and methods

This retrospective cohort study was conducted at a single center and enrolled 489 elderly patients who underwent surgery between May 1, 2020, and March 31, 2021. Patients were divided into the sleep disorder (SD) and non-sleep disorder (NSD) groups according to the occurrence of one or more symptoms of insomnia within one month or sleep- Numerical Rating Scale (NRS)≥6 before surgery. The primary outcome was the incidence of POD. Propensity score matching analysis was performed between the two groups. Multiple logistic regression analysis was performed to identify the risk factors for POD.

Results

In both the unmatched cohort (16.0% vs 6.7%, P=0.003) and the matched cohort (17.0% vs 6.2%, P=0.023), the incidence of POD was higher in the SD group than in the NSD group. In addition, the postoperative sleep quality and the VAS score at postoperative 24 h were significantly lower in the SD group than in the NSD group. Multivariate logistic regression analysis indicated that age (Odds Ratio, 1.13 [95% CI: 1.04-1.23], P=0.003) and preoperative sleep disturbance (Odds Ratio, 3.03 [95% CI: 1.09-9.52], P=0.034) were independent risk factors for the development of POD.

Conclusion

The incidence of POD was higher in patients with pre-existing sleep disturbance than those without it. Whether improving sleep quality for preoperative sleep disturbance may help prevent POD remains to be determined.

Comprehensive overview of the anesthesiology research landscape: A machine Learning Analysis of 737 NIH-funded anesthesiology primary Investigator's publication trends

Background

Anesthesiology plays a crucial role in perioperative care, critical care, and pain management, impacting patient experiences and clinical outcomes. However, our understanding of the anesthesiology research landscape is limited. Accordingly, we initiated a data-driven analysis through topic modeling to uncover research trends, enabling informed decision-making and fostering progress within the field.

Methods

The easyPubMed R package was used to collect 32,300 PubMed abstracts spanning from 2000 to 2022. These abstracts were authored by 737 Anesthesiology Principal Investigators (PIs) who were recipients of National Institute of Health (NIH) funding from 2010 to 2022. Abstracts were preprocessed, vectorized, and analyzed with the state-of-the-art BERTopic algorithm to identify pillar topics and trending subtopics within anesthesiology research. Temporal trends were assessed using the Mann-Kendall test.

Results

The publishing journals with most abstracts in this dataset were Anesthesia & Analgesia 1133, Anesthesiology 992, and Pain 671. Eight pillar topics were identified and categorized as basic or clinical sciences based on a hierarchical clustering analysis. Amongst the pillar topics, "Cells & Proteomics" had both the highest annual and total number of abstracts. Interestingly, there was an overall upward trend for all topics spanning the years 2000-2022. However, when focusing on the period from 2015 to 2022, topics "Cells & Proteomics" and "Pulmonology" exhibit a downward trajectory. Additionally, various subtopics were identified, with notable increasing trends in "Aneurysms", "Covid 19 Pandemic", and "Artificial intelligence & Machine Learning".

Conclusion

Our work offers a comprehensive analysis of the anesthesiology research landscape by providing insights into pillar topics, and trending subtopics. These findings contribute to a better understanding of anesthesiology research and can guide future directions.

Differences in Delirium Evaluation and Pharmacologic Management in Children With Developmental Delay: A Retrospective Case-Control Study

Delirium is associated with increased mortality and cost, decreased neurocognition, and decreased quality of life in the pediatric intensive care unit (PICU) population. The Cornell Assessment for Pediatric Delirium (CAPD) is used in PICUs for delirium screening but lacks specificity in children with developmental delay (DD). Within a cohort of children receiving pharmacologic treatment for intensive care unit (ICU) delirium, we compared delirium scoring and medication management between children with and without DD. We hypothesized that CAPD scores and treatment decisions would differ between DD and neurotypical (NT) patients. In this retrospective case-control study, we queried the medical record of patients admitted to our PICU with respiratory failure from June 2018 to March 2022 who received antipsychotics typically used for ICU delirium. Antipsychotics prescribed for home use were excluded. Nonparametric statistics compared demographics, CAPD scores, medication choice, dosing (mg/kg), and medication continuation after discharge between those with and without DD based on the ICD-10 codes. Twenty-one DD admissions and 59 NT admissions were included. Groups did not significantly differ by demographics, LOS, drug, or initial dosage. DD patients had higher median CAPD scores at admission (17 vs 13; P = .02) and treatment initiation (18 vs 16.5; P = .05). Providers more frequently escalated doses in DD patients (13/21 vs 21/59; P = .04) and discharged them home on new antipsychotics (7/21 vs 5/59; P = .01). DD patients experience delirium screening and management differently than NT counterparts. Providers should be aware of baseline elevated scores in DD patients and carefully attend to indications for dosage escalation. Further work is needed to understand if prolonged duration, even after hospital discharge, benefits patients, or represents potential disparity in care.

The association between midazolam premedication and postoperative delirium - a retrospective cohort study

STUDY OBJECTIVE

To evaluate the association between midazolam premedication and postoperative delirium in a large retrospective cohort of patients ≥70 years.

DESIGN

Retrospective cohort study.

SETTING

A single tertiary academic medical center.

PATIENTS

Patients ≥70 years having elective non-cardiac surgery under general anesthesia from 2020 to 2021.

INTERVENTIONS

Midazolam premedication, defined as intravenous midazolam administration prior to induction of general anesthesia.

MEASUREMENTS

The primary outcome, postoperative delirium, was a collapsed composite outcome including at least one of the following: a positive 4A's test during post-anesthesia care unit stay and/or the initial 2 postoperative days; physician or nursing records reporting new-onset confusion as captured by the CHART-DEL instrument; or a positive 3D-CAM test. The association between midazolam premedication and postoperative delirium was assessed using multivariable logistic regression, adjusting for potential confounding variables. As secondary analysis, we investigated the association between midazolam premedication and a composite of other postoperative complications. Several sensitivity analyses were performed using similar regression models.

MAIN RESULTS

In total, 1973 patients were analyzed (median age 75 years, 47% women, 50% ASA score ≥ 3, 32% high risk surgery). The overall incidence of postoperative delirium was 15.3% (302/1973). Midazolam premedication was administered to 782 (40%) patients (median [IQR] dose 2 [1,2] mg). After adjustment for potential confounding variables, midazolam premedication was not associated with increased odds of postoperative delirium, with adjusted odds ratio of 1.09 (95% confidence interval 0.82-1.45; P = 0.538). Midazolam premedication was also not associated with the composite of other postoperative complications. Furthermore, no association was found between midazolam premedication and postoperative delirium in any of the sensitivity analyses preformed.

CONCLUSIONS

Our results suggest that low doses of midazolam can be safely used to pre-medicate elective surgical patients 70 years or older before non-cardiac surgery, without significant effect on the risk of developing postoperative delirium.

Role of Blood-Brain Barrier Dysfunction in Delirium following Non-cardiac Surgery in Older Adults

OBJECTIVE

Although animal models suggest a role for blood-brain barrier dysfunction in postoperative delirium-like behavior, its role in postoperative delirium and postoperative recovery in humans is unclear. Thus, we evaluated the role of blood-brain barrier dysfunction in postoperative delirium and hospital length of stay among older surgery patients.

METHODS

Cognitive testing, delirium assessment, and cerebrospinal fluid and blood sampling were prospectively performed before and after non-cardiac, non-neurologic surgery. Blood-brain barrier dysfunction was assessed using the cerebrospinal fluid-to-plasma albumin ratio (CPAR).

RESULTS

Of 207 patients (median age = 68 years, 45% female) with complete CPAR and delirium data, 26 (12.6%) developed postoperative delirium. Overall, CPAR increased from before to 24 hours after surgery (median change = 0.28, interquartile range [IQR] = -0.48 to 1.24, Wilcoxon p = 0.001). Preoperative to 24 hours postoperative change in CPAR was greater among patients who developed delirium versus those who did not (median [IQR] = 1.31 [0.004 to 2.34] vs 0.19 [-0.55 to 1.08], p = 0.003). In a multivariable model adjusting for age, baseline cognition, and surgery type, preoperative to 24 hours postoperative change in CPAR was independently associated with delirium occurrence (per CPAR increase of 1, odds ratio = 1.30, 95% confidence interval [CI] = 1.03-1.63, p = 0.026) and increased hospital length of stay (incidence rate ratio = 1.15, 95% CI = 1.09-1.22, p < 0.001).

INTERPRETATION

Postoperative increases in blood-brain barrier permeability are independently associated with increased delirium rates and postoperative hospital length of stay. Although these findings do not establish causality, studies are warranted to determine whether interventions to reduce postoperative blood-brain barrier dysfunction would reduce postoperative delirium rates and hospital length of stay. ANN NEUROL 2023;94:1024-1035.

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.

A Role for Blood-brain Barrier Dysfunction in Delirium following Non-Cardiac Surgery in Older adults

Objective

Although animal models suggest a role for blood-brain barrier dysfunction in postoperative delirium-like behavior, its role in postoperative delirium and postoperative recovery in humans is unclear. Thus, we evaluated the role of blood-brain barrier dysfunction in postoperative delirium and hospital length of stay among older surgery patients.

Methods

Cognitive testing, delirium assessment, and cerebrospinal fluid and blood sampling were prospectively performed before and after non-cardiac, non-neurologic surgery. Blood-brain barrier dysfunction was assessed using the cerebrospinal fluid-to-plasma albumin ratio (CPAR).

Results

Of 207 patients (median age 68, 45% female) with complete CPAR and delirium data, 26 (12.6%) developed postoperative delirium. Overall, CPAR increased from before to 24-hours after surgery (median postoperative change 0.28, [IQR] [-0.48-1.24]; Wilcoxon p=0.001). Preoperative to 24-hour postoperative change in CPAR was greater among patients who developed delirium vs those who did not (median [IQR] 1.31 [0.004, 2.34] vs 0.19 [-0.55, 1.08]; p=0.003). In a multivariable model adjusting for age, baseline cognition, and surgery type, preoperative to 24-hour postoperative change in CPAR was independently associated with delirium incidence (per CPAR increase of 1, OR = 1.30, [95% CI 1.03-1.63]; p=0.026) and increased hospital length of stay (IRR = 1.15 [95% CI 1.09-1.22]; p<0.001).

Interpretation

Postoperative increases in blood-brain barrier permeability are independently associated with increased delirium rates and postoperative hospital length of stay. Although these findings do not establish causality, studies are warranted to determine whether interventions to reduce postoperative blood-brain barrier dysfunction would reduce postoperative delirium rates and hospital length of stay.