Risk factors for postoperative delirium: An umbrella review of systematic reviews

Mitochondrial Dysfunction of Peripheral Platelets as a Predictive Biomarker for Postoperative Delirium in Elderly Patients

OBJECTIVE

To determine the association between the preoperative Bioenergetic Health Index (BHI) of platelets and the occurrence of postoperative delirium (POD) in elderly patients.

METHODS

Elderly patients scheduled for major abdominal surgery under general anesthesia were included. The presence of POD was assessed within the 3 days after surgery. Seahorse XF analysis and transmission electron microscopy were utilized to evaluate the mitochondrial metabolism and morphology of platelets.

RESULTS

A total of 20 out of 162 participants developed POD. Participants with POD showed lower preoperative Mini-Mental State Examination scores and total protein levels, fewer educational years, longer surgery duration, higher mean platelet volume, and lower platelet BHI compared with those without POD. Damaged mitochondria with swollen appearance and distorted cristae was detected in platelets from participants with POD. Preoperative platelet BHI was independently associated with the occurrence of POD after adjusting for age, education, preoperative Mini-Mental State Examination score, preoperative mean platelet volume and total protein levels, surgical type and duration, and lymphocyte counts on the first postoperative day (OR 0.11, 95% CI 0.03-0.37, p < 0.001). The areas under the receiver operating curves for predicting POD were 0.83 (95% CI 0.76-0.88) for platelet BHI. It showed a sensitivity of 85.00% and specificity of 73.24%, with an optimal cutoff value of 1.61. Using a serial combination (mean platelet volume followed by BHI) yielded a sensitivity of 80.00% and specificity of 82.39%.

INTERPRETATION

Preoperative platelet BHI was independently associated with the occurrence of POD in elderly patients and has the potential as a screening biomarker for POD risk. ANN NEUROL 2024;96:74-86.

Preoperative Delirium Risk Screening in Patients Undergoing a Cardiac Surgery: Results from the Prospective Observational FINDERI Study

OBJECTIVE

Postoperative delirium (POD) is a common complication of cardiac surgery that is associated with higher morbidity, longer hospital stay, cognitive decline, and mortality. Preoperative assessments may help to identify patients´ POD risk. However, a standardized screening assessment for POD risk has not been established.

DESIGN

Prospective observational FINd DElirium RIsk factors (FINDERI) study.

PARTICIPANTS

Patients aged ≥50 years undergoing cardiac surgery.

MEASUREMENTS

The primary aim was to analyze the predictive value of the Delirium Risk Screening Questionnaire (DRSQ) prior to cardiac surgery. Secondary aims are to investigate cognitive, frailty, and geriatric assessments, and to use data-driven machine learning (ML) in predicting POD. Predictive properties were assessed using receiver operating characteristics analysis and multivariate approaches (regularized LASSO regression and decision trees).

RESULTS

We analyzed a data set of 504 patients (68.3 ± 8.2 years, 21.4% women) who underwent cardiac surgery. The incidence of POD was 21%. The preoperatively administered DRSQ showed an area under the curve (AUC) of 0.68 (95% CI 0.62, 0.73), and the predictive OR was 1.25 (95% CI 1.15, 1.35, p <0.001). Using a ML approach, a three-rule decision tree prediction model including DRSQ (score>7), Trail Making Test B (time>118), and Montreal Cognitive Assessment (score ≤ 22) was identified. The AUC of the three-rule decision tree on the training set was 0.69 (95% CI 0.63, 0.75) and 0.62 (95% CI 0.51, 0.73) on the validation set.

CONCLUSION

Both the DRSQ and the three-rule decision tree might be helpful in predicting POD risk before cardiac surgery.

Interpretable machine learning model for early prediction of delirium in elderly patients following intensive care unit admission: a derivation and validation study

Background and objective

Delirium is the most common neuropsychological complication among older adults admitted to the intensive care unit (ICU) and is often associated with a poor prognosis. This study aimed to construct and validate an interpretable machine learning (ML) for early delirium prediction in older ICU patients.

Methods

This was a retrospective observational cohort study and patient data were extracted from the Medical Information Mart for Intensive Care-IV database. Feature variables associated with delirium, including predisposing factors, disease-related factors, and iatrogenic and environmental factors, were selected using least absolute shrinkage and selection operator regression, and prediction models were built using logistic regression, decision trees, support vector machines, extreme gradient boosting (XGBoost), k-nearest neighbors and naive Bayes methods. Multiple metrics were used for evaluation of performance of the models, including the area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, specificity, recall, F1 score, calibration plot, and decision curve analysis. SHapley Additive exPlanations (SHAP) were used to improve the interpretability of the final model.

Results

Nine thousand seven hundred forty-eight adults aged 65 years or older were included for analysis. Twenty-six features were selected to construct ML prediction models. Among the models compared, the XGBoost model demonstrated the best performance including the highest AUC (0.836), accuracy (0.765), sensitivity (0.713), recall (0.713), and F1 score (0.725) in the training set. It also exhibited excellent discrimination with AUC of 0.810, good calibration, and had the highest net benefit in the validation cohort. The SHAP summary analysis showed that Glasgow Coma Scale, mechanical ventilation, and sedation were the top three risk features for outcome prediction. The SHAP dependency plot and SHAP force analysis interpreted the model at both the factor level and individual level, respectively.

Conclusion

ML is a reliable tool for predicting the risk of critical delirium in elderly patients. By combining XGBoost and SHAP, it can provide clear explanations for personalized risk prediction and more intuitive understanding of the effect of key features in the model. The establishment of such a model would facilitate the early risk assessment and prompt intervention for delirium.

Deciphering the dual role of N-methyl-D-Aspartate receptor in postoperative cognitive dysfunction: A comprehensive review

Postoperative cognitive dysfunction (POCD) is a common complication following surgery, adversely impacting patients' recovery, increasing the risk of negative outcomes, prolonged hospitalization, and higher mortality rates. The N-methyl-D-aspartate (NMDA) receptor, crucial for learning, memory, and synaptic plasticity, plays a significant role in the development of POCD. Various perioperative factors, including age and anesthetic use, can reduce NMDA receptor function, while surgical stress, inflammation, and pain may lead to its excessive activation. This review consolidates preclinical and clinical research to explore the intricate relationship between perioperative factors affecting NMDA receptor functionality and the onset of POCD. It discusses the influence of aging, anesthetic administration, perioperative injury, pain, and inflammation on the NMDA receptor-related pathophysiology of POCD. The comprehensive analysis presented aims to identify effective treatment targets for POCD, contributing to the improvement of patient outcomes post-surgery.

Development and validation of a new drug-focused predictive risk score for postoperative delirium in orthopaedic and trauma surgery patients

BACKGROUND

Postoperative delirium (POD) is the most common complication following surgery in elderly patients. During pharmacist-led medication reconciliation (PhMR), a predictive risk score considering delirium risk-increasing drugs and other available risk factors could help to identify risk patients.

METHODS

Orthopaedic and trauma surgery patients aged ≥ 18 years with PhMR were included in a retrospective observational single-centre study 03/2022-10/2022. The study cohort was randomly split into a development and a validation cohort (6:4 ratio). POD was assessed through the 4 A's test (4AT), delirium diagnosis, and chart review. Potential risk factors available at PhMR were tested via univariable analysis. Significant variables were added to a multivariable logistic regression model. Based on the regression coefficients, a risk score for POD including delirium risk-increasing drugs (DRD score) was established.

RESULTS

POD occurred in 42/328 (12.8%) and 30/218 (13.8%) patients in the development and validation cohorts, respectively. Of the seven evaluated risk factors, four were ultimately tested in a multivariable logistic regression model. The final DRD score included age (66-75 years, 2 points; > 75 years, 3 points), renal impairment (eGFR < 60 ml/min/1.73m2, 1 point), anticholinergic burden (ACB-score ≥ 3, 1 point), and delirium risk-increasing drugs (n ≥ 2; 2 points). Patients with ≥ 4 points were classified as having a high risk for POD. The areas under the receiver operating characteristic curve of the risk score model were 0.89 and 0.81 for the development and the validation cohorts, respectively.

CONCLUSION

The DRD score is a predictive risk score assessable during PhMR and can identify patients at risk for POD. Specific preventive measures concerning drug therapy safety and non-pharmacological actions should be implemented for identified risk patients.

Lower alpha frequency of intraoperative frontal EEG is associated with postoperative delirium: A secondary propensity-matched analysis

BACKGROUND

Postoperative delirium (POD) is a serious complication of surgery, especially in the elderly patient population. It has been proposed that decreasing the amount of anesthetics by titrating to an EEG index will lower POD rate, but clear evidence is missing. A strong age-dependent negative correlation has been reported between the peak oscillatory frequency of alpha waves and end-tidal anesthetic concentration, with older patients generating slower alpha frequencies. We hypothesized, that slower alpha oscillations are associated with a higher rate of POD.

METHOD

Retrospective analysis of patients` data from a prospective observational study in cardiac surgical patients approved by the Bernese Ethics committee. Frontal EEG was recorded during Isoflurane effect-site concentrations of 0.7 to 0.8 and peak alpha frequency was measured at highest power between 6 and 17 Hz. Delirium was assessed by chart review. Demographic and clinical characteristics were compared between POD and non-POD groups. Selection bias was addressed using nearest neighbor propensity score matching (PSM) for best balance. This incorporated 18 variables, whereas patients with missing variable information or without an alpha oscillation were excluded.

RESULT

Of the 1072 patients in the original study, 828 were included, 73 with POD, 755 without. PSM allowed 328 patients into the final analysis, 67 with, 261 without POD. Before PSM, 8 variables were significantly different between POD and non-POD groups, none thereafter. Mean peak alpha frequency was significantly lower in the POD in contrast to non-POD group before and after matching (7.9 vs 8.9 Hz, 7.9 vs 8.8 Hz respectively, SD 1.3, p < 0.001).

CONCLUSION

Intraoperative slower frontal peak alpha frequency is independently associated with POD after cardiac surgery and may be a simple intraoperative neurophysiological marker of a vulnerable brain for POD. Further studies are needed to investigate if there is a causal link between alpha frequency and POD.

The effectiveness of preoperative delirium prevention in intermediate to high-risk older surgical patients: A systematic review

BACKGROUND

Few reviews have addressed delirium prevention among intermediate to high-risk older surgical patients.

AIMS

To map preoperative delirium prevention interventions for older surgical patients at intermediate to high risk of developing delirium, assess outcomes and identify gaps in knowledge.

DESIGN

Systematic narrative review of randomised controlled trials reported following the PRISMA checklist.

METHODS

A systematic search was conducted of the literature published from 1990 to October 2022 in Medline, CINAHL and Ageline and of the grey literature in Google Scholar. Randomised controlled trials were retrieved that assessed the effectiveness of preoperative delirium prevention interventions for older surgical patients at intermediate to high risk of delirium. Data were extracted using a data extraction tool, and results were tabulated. Studies were assessed for bias using the Cochrane Collaboration Risk of Bias tool.

RESULTS

Twenty-one studies met the selection criteria including N = 5096 participants. Two studies tested cognitive training, two studies tested fascia iliaca compartment block and one study assessed femoral nerve block. Ten studies tested prophylactic medications including methylprednisolone. Five studies investigated geriatric assessment and management. One study assessed transcutaneous electrical acupoint stimulation. In the two studies testing fascia iliaca compartment block, there was a reduction in postoperative delirium for orthopaedic patients. Methylprednisolone reduced postoperative delirium in orthopaedic patients and in those undergoing gastrointestinal surgery. Results of all other interventions on the occurrence of postoperative delirium and additional outcomes including the severity and duration of delirium were inconclusive.

CONCLUSIONS

Despite the promising results for fascia iliaca compartment block and methylprednisolone, there is limited knowledge regarding evidence-based delirium prevention interventions. Most studies had small sample sizes indicating that the current evidence is exploratory. There is an urgent need for the funding and conduct of trials to test preventative interventions for older surgical patients at intermediate to high risk of developing delirium.

The association between cataract surgery and mental health in older adults: a review

BACKGROUND

Although cataract surgery has been proposed as a potentially modifiable protective factor for enhancing emotional well-being in cataract patients, studies examining the relationship between anxiety or depression and cataract surgery have yielded inconsistent findings. This review summarizes existing evidence to establish whether cataract surgery is associated with depression and anxiety in older adults.

METHODS

A literature search was conducted across PubMed, Medline, Web of Science, and Embase databases. An initial screening by abstracts and titles was performed, followed by a review and assessment of the methodological quality of the relevant full papers, and final inclusion of 44 studies were deemed eligible for inclusion in this review.

RESULTS

Among 44 included studies, 36 studies (81.8%) were observational studies concerning the association of cataract surgery or cataracts with anxiety or depression, four studies (9.1%) were interventional studies, and four studies (9.1%) were reviews. Cataract surgery notably enhances the mental health of individuals with impaired vision. However, the multifaceted nature of psychological well-being, influenced by various factors, suggests that cataract surgery may not address all aspects comprehensively. Additionally, preoperative anxiety and depression significantly impact cataract surgery outcomes.

CONCLUSION

Vision impairment in older adults is closely associated with increased symptoms of depression and anxiety. While surgical intervention for cataracts improves these symptoms, it might be less effective for mental disorders with multifactorial causes. Notably, anxiety or depression poses challenges to successful preoperative and intraoperative cataract surgeries.

The efficacy of extracorporeal shock wave therapy for knee osteoarthritis : an umbrella review

BACKGROUND

An umbrella review was conducted to compare the effectiveness of extracorporeal shock wave therapy (ESWT) versus non-ESWT in the treatment of knee osteoarthritis (KOA).

MATERIALS AND METHODS

Three databases including PubMed, Embase and Web of science were searched up to September 2023. Literature screening, quality evaluation, and data extraction were performed according to inclusion and exclusion criteria. Meta-analysis of outcome indicators was performed using Revman 5.4 software.

RESULTS

A total of eight meta-analysis were included in this umbrella review. All meta-analysis were graded against a Measurement Tool to Assess Systematic Reviews 2 (AMSTAR 2) and scored between 8 and 11. Compared to the sham group, the ESWT group showed better results in WOMAC (Western Ontario and McMaster Universities Arthritis Index) [mean difference (MD)=-2.94, 95% CI: -5.52, -0.37, P=0.03, I²=60%], Visual Analog Scale (VAS) (MD=-2.0, 95% CI: -2.5, -1.5, P<0.01, I²=0%), range of motion (ROM) (MD=17.55, 95% CI: 13.49, 21.61, P<0.00001, I²=0%), and Lequesne index (MD=-2.85, 95% CI: -3.64, -2.07, P<0.00001, I²=48%).

CONCLUSION

Based on the results of our analysis, ESWT is now an effective therapy for improving pain and function in patients with KOA.

Factors associated with delirium in a real-world acute-care setting: analysis considering the interdependence of clinical variables with the frailty syndrome

PURPOSE

Delirium risk assessment in the acute-care setting generally does not account for frailty. The objective of this retrospective study was to identify factors associated with delirium, considering the interdependency of clinical variables with frailty syndrome in complex older patients.

METHODS

The clinical records of 587 participants (248 M, median age 84) were reviewed, collecting clinical, anamnestic and pharmacological data. Frailty syndrome was assessed with the Clinical Frailty Scale (CFS). Delirium was the main study endpoint. The correlations of the considered anamnestic and clinical variables with delirium and its subtypes were investigated selecting only those variables not showing a high overlap with frailty. Correlations associated with a 25% excess of frequency of delirium in comparison with the average of the population were considered as statistically significant.

RESULTS

Delirium was detected in 117 (20%) participants. The presence of one among age > 85 years old, CFS > 4 and invasive devices explained 95% of delirium cases. The main factors maximizing delirium incidence at the individual level were dementia, other psychiatric illness, chronic antipsychotic treatment, and invasive devices. The coexistence of three of these parameters was associated with a peak frequency of delirium, ranging from 57 to 61%, mostly hypoactive forms.

CONCLUSIONS

In acute-care wards, frailty exhibited a strong association with delirium during hospitalization, while at the individual level, dementia and the use of antipsychotics remained important risk factors. Modern clinical prediction tools for delirium should account for frailty syndrome.

Knowledge mapping and research trends on perioperative neurocognitive disorder from 1990 to 2022: a bibliometric analysis

Introduction

Perioperative neurocognitive disorder (PND) has attracted consistently increasing attention worldwide. However, there are few bibliometric studies that systematically evaluate this field. This study aimed to visualize the knowledge structure and research trends in PND through bibliometrics to help understand the future development of basic and clinical research.

Methods

Literature related to PND in Web of Science and PubMed from 1990 to 2022 were collected through keywords retrospectively. Additionally, the source information, citation information, etc. of these publications were extracted. Finally, bibliometric analysis was performed by visualization software and statistical software.

Results

There were 2837 articles and reviews in total. An exponential rise in PND-related publications was observed. China had the most publication, followed by the US and Germany. The institution with the most output and citations was Harvard University (149 papers, 8966 citations). The most prominent author was Marcantonio Edward R with 66 publications and 5721 citations. The journal with the highest productivity for PND research was Frontiers in Aging Neuroscience followed by Anesthesia and Analgesia. Keywords were identified as six topics, including postoperative delirium, postoperative neurocognitive disorder, cardiac surgery, anaesthesia, orthopedic surgery, and dementia. According to keyword analysis, the most recent popular keywords in PND research were prevention, older patients, emergence delirium, orthopedic surgery, and dexmedetomidine.

Conclusions

Publications on PND are increasing at an alarming rate from 1990 to 2022. Current research and future trends will concentrate on the prevention and treatment of PND, as well as PND associated with orthopedic surgery in older adults.

Cognitive Training for Reduction of Delirium in Patients Undergoing Cardiac Surgery: A Randomized Clinical Trial

IMPORTANCE

Postoperative delirium is a common and impactful neuropsychiatric complication in patients undergoing coronary artery bypass grafting surgery. Cognitive training may enhance cognitive reserve, thereby reducing postoperative delirium.

OBJECTIVE

To determine whether preoperative cognitive training reduces the incidence of delirium in patients undergoing coronary artery bypass grafting.

DESIGN, SETTING, and PARTICIPANTS

This prospective, single-blind, randomized clinical trial was conducted at 3 university teaching hospitals in southeastern China with enrollment between April 2022 and May 2023. Eligible participants included those scheduled for elective coronary artery bypass grafting who consented and enrolled at least 10 days before surgery.

INTERVENTIONS

Participating patients were randomly assigned 1:1, stratified by site, to either routine care or cognitive training, which included substantial practice with online tasks designed to enhance cognitive functions including memory, imagination, reasoning, reaction time, attention, and processing speed.

MAIN OUTCOMES AND MEASURES

The primary outcome was occurrence of delirium during postoperative days 1 to 7 or until hospital discharge, diagnosed using the Confusion Assessment Method or the Confusion Assessment Method for Intensive Care Units. Secondary outcomes were postoperative cognitive dysfunction, delirium characteristics, and all-cause mortality within 30 days following the operation.

RESULTS

A total of 218 patients were randomized and 208 (median [IQR] age, 66 [58-70] years; 64 female [30.8%] and 144 male [69.2%]) were included in final analysis, with 102 randomized to cognitive training and 106 randomized to routine care. Of all participants, 95 (45.7%) had only a primary school education and 54 (26.0%) had finished high school. In the cognitive training group, 28 participants (27.5%) developed delirium compared with 46 participants (43.4%) randomized to routine care. Those receiving cognitive training were 57% less likely to develop delirium compared with those receiving routine care (adjusted odds ratio [aOR] 0.43; 95% CI, 0.23-0.77; P = .007). Significant differences were observed in the incidence of severe delirium (aOR, 0.46; 95% CI, 0.25-0.82; P = .01), median (IQR) duration of delirium (0 [0-1] days for cognitive training vs 0 [0-2] days for routine care; P = .008), and median (IQR) number of delirium-positive days (0 [0-1] days for cognitive training vs 0 [0-2] days for routine care; P = .007). No other secondary outcomes differed significantly.

CONCLUSIONS AND RELEVANCE

In this randomized trial of 208 patients undergoing coronary artery bypass grafting, preoperative cognitive training reduced the incidence of postoperative delirium. However, our primary analysis was based on fewer than 75 events and should therefore be considered exploratory and a basis for future larger trials.

Trial Registration

Chinese Clinical Trial Registry Identifier: ChiCTR2200058243.

Preoperative Intrathecal Morphine is Associated With Reduced Postoperative Pain, Agitation, and Delirium In Living Donor Kidney Transplantation Recipients

BACKGROUND

Postoperative delirium after organ transplantation can lead to increased length of hospital stay and mortality. Because pain is an important risk factor for delirium, perioperative analgesia with intrathecal morphine (ITM) may mitigate postoperative delirium development. We evaluated if ITM reduces postoperative delirium incidence in living donor kidney transplant (LDKT) recipients.

METHODS

Two hundred ninety-six patients who received LDKT between 2014 and 2018 at our hospital were retrospectively analyzed. Recipients who received preoperative ITM (ITM group) were compared with those who did not (control group). The primary outcome was postoperative delirium based on the Confusion Assessment Method for Intensive Care Unit results during the first 4 postoperative days.

RESULTS

Delirium occurred in 2.6% (4/154) and 7.0% (10/142) of the ITM and control groups, respectively. Multivariable analysis showed age (odds ratio [OR]: 1.07, 95% CI: 1.01-1.14; P = .031), recent smoking (OR: 7.87, 95% CI: 1.43-43.31; P = .018), preoperative psychotropics (OR: 23.01, 95% CI: 3.22-164.66; P = .002) were risk factors, whereas ITM was a protective factor (OR: 0.23, 95% CI: 0.06-0.89; P = .033).

CONCLUSIONS

Preoperative ITM showed an independent association with reduced post-LDKT delirium. Further studies and the development of regional analgesia for delirium prevention may enhance the postoperative recovery of transplant recipients.

Analysis of risk factors for major post-operative complications following intraperitoneal hyperthermic perfusion for pseudomyxoma peritonei: A retrospective cohort study

INTRODUCTION

Pseudomyxoma peritonei (PMP) is a condition characterised by the presence of gelatinous tumour-like growth within the peritoneal cavity. Combined cytoreductive surgery and intraperitoneal chemotherapy have shown to improve the survival rate in PMP patients. However, post-operative complications such as cognitive dysfunction, respiratory insufficiency and acute renal failure are still observed. This retrospective study aims to explore the risk factors associated with major post-operative complications and specifically investigate the correlation with intraoperative hypotension.

PATIENTS AND METHODS

This retrospective cohort study included PMP patients treated at Beijing Aerospace Center Hospital from 1 June, 2014 to 30 December, 2020. The primary outcome measures were major post-operative complications, including neurological, pulmonary, cardiovascular, surgical complications, acute hepatic injury and acute kidney injuries. The secondary outcome measures included infection, fever and deep venous thrombosis. Statistical analysis was conducted using EmpowerStats and R software.

RESULTS

A total of 782 patients were screened, and 668 patients were included in the statistical analysis. Amongst them, 234 (35.03%) individuals experienced major post-operative complications. Factors such as pre-operative American Society of Anaesthesiologists grading, age, haemoglobin and albumin levels, intraoperative mean arterial pressure, blood loss, fluid replacement volume, method of intraperitoneal hyperthermic perfusion and post-operative requirement for intensive care unit mechanical ventilation were found to be correlated with major complications.

CONCLUSION

The identified risk factors provide valuable insights for improving clinical pathways in the management of PMP. Further prospective studies are warranted to establish the association between these factors and patient outcomes.

Effectiveness of remimazolam in preventing postoperative delirium in elderly patients with proximal femoral fractures

PURPOSE

Elderly patients with proximal femoral fractures are known to be a high-risk group for postoperative delirium (POD). The aim of this study was to determine the association of the benzodiazepine drug remimazolam with POD in elderly patients with proximal femoral fractures.

METHODS

In this single-center retrospective observational study, we included patients aged 65 years or older who underwent general anesthesia for proximal femoral fractures. We collected data for the incidence of POD within 3 days after surgery. We also obtained data for complications, preoperative blood examinations, maintenance anesthetic and intraoperative vital data. The occurrence of POD in patients who received remimazolam for general anesthesia (remimazolam group) was compared to that in patients who received general anesthesia with other anesthetic agents (other group). We finally conducted a multivariate analysis to assess the independent association of remimazolam with the risk of POD.

RESULTS

A total of 230 patients, including 54 patients who received remimazolam for maintenance anesthesia, were included in this study. The incidence of POD in the patients was 26.1%. The incidence of delirium within 3 days after surgery was significantly lower in the remimazolam group than in the other group (14.8% vs. 29.5%, p  =  0.03). The multivariate analysis showed that the use of remimazolam independently reduced the occurrence of POD (adjusted odds ratio  =  0.42, p  =  0.04).

CONCLUSION

This retrospective observational study showed that the use of remimazolam is independently associated with a reduced incidence of POD. Remimazolam may be considered as an option to reduce POD in elderly patients with proximal femoral fractures.

Association of sleep quality on the night of operative day with postoperative delirium in elderly patients: A prospective cohort study

BACKGROUND

Sleep disturbances in the peri-operative period have been associated with adverse outcomes, including postoperative delirium (POD). However, research on sleep quality during the immediate postoperative period is limited.

OBJECTIVES

This study aimed to investigate the association between sleep quality on the night of the operative day assessed using the Sleep Quality Numeric Rating Scale (SQ-NRS), and the incidence of POD in a large cohort of surgical patients.

DESIGN

A prospective cohort study.

SETTING

A tertiary hospital in China.

PATIENTS

This study enrolled patients aged 65 years or older undergoing elective surgery under general anaesthesia. The participants were categorised into the sleep disturbance and no sleep disturbance groups according to their operative night SQ-NRS.

MAIN OUTCOME MEASURES

The primary outcome was delirium incidence, whereas the secondary outcomes included acute kidney injury, stroke, pulmonary infection, cardiovascular complications and all-cause mortality within 1 year postoperatively.

RESULTS

In total, 3072 patients were included in the analysis of this study. Among them, 791 (25.72%) experienced sleep disturbances on the night of operative day. Patients in the sleep disturbance group had a significantly higher risk of developing POD (adjusted OR 1.43, 95% CI 1.11 to 1.82, P  = 0.005). Subgroup analysis revealed that age 65-75 years; male sex; ASA III and IV; haemoglobin more than 12 g l -1 ; intra-operative hypotension; surgical duration more than 120 min; and education 9 years or less were significantly associated with POD. No interaction was observed between the subgroups. No significant differences were observed in the secondary outcomes, such as acute kidney injury, stroke, pulmonary infection, cardiovascular complications and all-cause mortality within 1 year postoperatively.

CONCLUSIONS

The poor subjective sleep quality on the night of operative day was independently associated with increased POD risk, especially in certain subpopulations. Optimising peri-operative sleep may reduce POD. Further research should investigate potential mechanisms and causal relationships.

TRIAL REGISTRY

chictr.org.cn: ChiCTR1900028545.

Association of reduced cerebrospinal fluid NPTX2 levels with postoperative delirium in patients undergoing knee/hip replacement: a prospective cohort study

BACKGROUND

Postoperative delirium (POD) is a common complication with poor prognosis in the elderly, but its mechanism has not been fully elucidated. There is evidence that the changes in synaptic activity in the brain are closely related to the occurrence of POD. And neuronal pentraxin 2 (NPTX2) can regulate synaptic activity in vivo.

AIMS

This study aims to explore whether decreased NPTX2 levels affects POD and whether the cerebrospinal fluid (CSF) biomarkers of POD mediate this association.

METHODS

In this prospective cohort study, we interviewed patients with knee/hip replacement 1 day before surgery to collect patient information and assess their cognitive function. CSF was extracted for measuring the CSF levels of NPTX2 and other POD biomarkers on the day of surgery. And postoperative follow-up visits were performed 1-7 days after surgery.

RESULTS

Finally, 560 patients were included in the study. The patients were divided into POD group and NPOD (non-POD) group. The POD group had a median age of 80 years, a female proportion of 45%, a median BMI of 24.1 kg/m2, and a median years of education of 9 years. The Mann-Whitney U test showed that CSF NPTX2 levels were significantly lower in POD group, compared with the NPOD group (P < 0.05). Univariate binary logistic regression analysis showed that reduced CSF levels of NPTX2 protected against POD (crude OR = 0.994, 95% CI 0.993-0.995, P < 0.001). The receiver-operating characteristic (ROC) curve indicated that CSF NPTX2 level had high predictive value for POD. Mediation analyses showed that CSF T-tau (mediating proportion = 21%) and P-tau (mediating proportion = 29%) had significant mediating effects on the association between CSF NPTX2 and POD.

CONCLUSION

CSF NPTX2 levels were associated with the occurrence of POD. Low CSF NPTX2 levels may be an independent protective factor for POD. CSF T-tau and P-tau could mediate the association between CSF NPTX2 and POD occurrence.

CLINICAL TRIAL REGISTRATION

The trial registration number (TRN): ChiCTR2200064740, Date of Registration: 2022-10-15.

Development of a complex intervention to prevent delirium in older hospitalized patients by optimizing discharge and transfer processes and involving caregivers: A multi-method study

BACKGROUND

Delirium is a common yet challenging condition in older hospitalized patients, associated with various adverse outcomes. Environmental factors, such as room changes, may contribute to the development or severity of delirium. Most previous research has focused on preventing and reducing this condition by addressing risk factors and facilitating reorientation during hospital stay.

OBJECTIVE

We aimed to systematically develop a complex intervention to prevent delirium in older hospitalized patients by optimizing discharge and transfer processes and involving caregivers during and after these procedures. The intervention combines stakeholder and expert opinions, evidence, and theory. This article provides guidance and inspiration to research groups in developing complex interventions according to the recommendations in the Medical Research Council framework for complex interventions.

DESIGN AND METHODS

A stepwise multi-method study was conducted. The preparation phase included analysis of the context and current practice via focus groups. Based on these results, an expert workshop was organized, followed by a Delphi survey. Finally, the intervention was modeled and a program theory was developed, including a logic model.

RESULTS

A complex intervention was developed in an iterative process, involving healthcare professionals, delirium experts, researchers, as well as caregiver and patient representatives. The key intervention component is an 8-point-program, which provides caregivers with recommendations for preventing delirium during the transition phase and in the post-discharge period. Information materials (flyers, handbook, videos, posters, defined "Dos and Don'ts", discharge checklist), training for healthcare professionals, and status analyses are used as implementation strategies. In addition, roles were established for gatekeepers to act as leaders, and champions to serve as knowledge multipliers and trainers for the multi-professional team in the hospitals.

CONCLUSIONS

This study serves as an example of how to develop a complex intervention. In an additional step, the intervention and implementation strategies will be investigated for feasibility and acceptability in a pilot study with an accompanying process evaluation.

TWEETABLE ABSTRACT

Delirium prevention can benefit from optimizing discharge and transfer processes and involving caregivers of older patients in these procedures.

STUDY REGISTRATION

DRKS00017828, German Register of Clinical Studies, date of registration 17.09.2019.

Cognitive function and ability to complete a web-based geriatric assessment among older adults with cancer

BACKGROUND

The purpose of this study was determined whether cognitive impairment is associated with time taken to complete the electronic rapid fitness assessment (eRFA). We hypothesized that taking more time to complete the eRFA will indicate worsened cognitive function.

METHODS

We retrospectively identified patients who presented to the Memorial Sloan Kettering Cancer Center Geriatrics Service for preoperative evaluation and completed the eRFA as a part of their preoperative assessment from February 2015 to December 2020. Cognitive function was assessed using the Mini-Cog©, which is a screening test for cognitive function status. Patients in this study underwent elective surgery and had a hospital length of stay ≥1 day. Time to complete the eRFA was automatically recorded by a web-based tool; assistance with eRFA completion was self-reported by the patient. In total, 2599 patients were included, of which 2387 had available Mini-Cog© scores.

RESULTS

Overall, 50% of surveys were completed without assistance, 37% were completed with assistance, and 13% were completed by somebody else; Mini-Cog© scores were lower, corresponding to worsened cognitive function status, in patients requiring assistance (median score respectively, 5 vs. 4 vs. 3; p-value <0.0001; rates of cognitive impairment 7.5%, 22%, and 38%). Among patients who completed the questionnaire independently, greater cognitive impairment was associated with longer time to complete the eRFA (change in score per 5 min = -0.09; 95% CI -0.14, -0.03; p = 0.002).

CONCLUSIONS

We found evidence that requirement for assistance in completing web-based questionnaires, and time taken to complete a questionnaire, predict which patients benefit from more comprehensive cognitive function assessments. Future studies should further validate this finding in a more diverse population and establish optimal clinical pathways.

Promising Effects of Montelukast for Critically Ill Asthma Patients via a Reduction in Delirium

Background: Montelukast (MTK), a potent antagonist of cysteinyl leukotriene receptor 1, has shown therapeutic promise for the treatment of neuropsychiatric disorders. Delirium, a common complication in critically ill patients, lacks effective treatment. This study aims to explore the impact of pre-intensive care unit (ICU) MTK use on in-hospital delirium incidence and, subsequent, prognosis in critically ill patients. Methods: A retrospective cohort study (n = 6344) was conducted using the MIMIC-IV database. After propensity score matching, logistic/Cox regression, E-value sensitivity analysis, and causal mediation analysis were performed to assess associations between pre-ICU MTK exposure and delirium and prognosis in critically ill patients. Results: Pre-ICU MTK use was significantly associated with reduced in-hospital delirium (OR: 0.705; 95% CI 0.497-0.999; p = 0.049) and 90-day mortality (OR: 0.554; 95% CI 0.366-0.840; p = 0.005). The association was more significant in patients without myocardial infarction (OR: 0.856; 95% CI 0.383-0.896; p = 0.014) and could be increased by extending the duration of use. Causal mediation analysis showed that the reduction in delirium partially mediated the association between MTK and 90-day mortality (ACME: -0.053; 95% CI -0.0142 to 0.0002; p = 0.020). Conclusions: In critically ill patients, MTK has shown promising therapeutic benefits by reducing the incidence of delirium and 90-day mortality. This study highlights the potential of MTK, beyond its traditional use in respiratory disease, and may contribute to the development of novel therapeutic strategies for delirium.

Risk factors for postoperative delirium in orthopaedic hip surgery patients: a database review

BACKGROUND

Postoperative delirium is a common problem affecting admitted patients that decreases patient satisfaction and increases the cost and complexity of care. The purpose of this study was to use the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database to compare rates and risk factors of postoperative delirium for total hip arthroplasty (THA) and hemiarthroplasty patients indicated for osteoarthritis or proximal femur fracture.

METHODS

The 2021 NSQIP database was queried for patients using Current Procedural Terminology (CPT) codes for THA and hemiarthroplasty and ICD-10 codes for osteoarthritis or proximal femur fracture. Demographic, past medical history, preoperative labs, and functional status data were recorded. Procedural data were also collected. Finally, postoperative outcomes and complications were reviewed.

RESULTS

Overall, 16% of patients had postoperative delirium. Delirium patients were older on average (82.4 years vs. 80.7 years, p < 0.001), had a lower BMI (19.5 vs. 24.8, p < 0.001), were more likely to have a history of dementia (54.6% vs. 13.6%, p < 0.001), were less likely to have an independent functional status (p < 0.001) or live alone (p < 0.001), and were more likely to have sustained a recent fall (p < 0.001). Delirium patients were more likely to be hyponatremic or hypernatremic (p = 0.002), anemic (p < 0.001), and severely dehydrated (p < 0.001), among other lab abnormalities. Delirium patients were also more likely to experience additional postoperative complications, including pneumonia, pulmonary embolism, urinary tract infection, stroke, cardiac arrest, sepsis, and unplanned reoperation and readmission after discharge (all p < 0.05).

CONCLUSIONS

In this study, factors associated with postoperative delirium in patients undergoing hemiarthroplasty and THA were identified, including older age, lower BMI, certain medical conditions, decreased functional status, certain lab abnormalities, and postoperative complications. These findings can be used by clinicians to better inform care and to determine when orthopaedic joint replacement patients may be at an increased risk for postoperative delirium.

Effect of remimazolam on electroencephalogram burst suppression in elderly patients undergoing cardiac surgery: Protocol for a randomized controlled noninferiority trial

Background

Postoperative delirium (POD) is a common complication following cardiac surgery and increases postoperative morbidity and mortality. Intraoperative electroencephalogram (EEG) burst suppression suggests excessively deep anesthesia and predicts POD. Use of remimazolam provides a stable hemodynamic status and an appropriate depth of anesthesia. We aim to assess remimazolam administered for anesthesia and sedation in elderly patients having cardiac surgery.

Methods

This is a randomized controlled clinical trial with noninferiority design. A total of 260 elderly patients aged equal to or greater than 60 years undergoing cardiac surgery will be randomly allocated to receive remimazolam or propofol (1:1) for general anesthesia and postoperative sedation until extubation. The primary outcome is the cumulative time with EEG burst suppression which is obtained from the SedLine system. The noninferiority margin is 2.0 min. The secondary outcomes include the POD occurrence within the first 5 days postoperatively and the duration of perioperative hypotension.

Discussion

This noninferiority trial is the first to evaluate the effect of perioperative remimazolam administration on EEG burst suppression, POD occurrence, and duration of hypotension in elderly patients who undergo cardiac surgery.

Trial registration

Chinese Clinical Trial Registry (ChiCTR2200056353).

Role of supplemental regional blocks on postoperative neurocognitive dysfunction after major non-cardiac surgeries: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND/IMPORTANCE

Postoperative neurocognitive dysfunction (PNCD) is a frequent and preventable complication after surgery. The large high-quality evidence for the efficacy of supplemental regional analgesia blocks (RAB) for preventing PNCD is still elusive.

OBJECTIVE

The objective of this meta-analysis was to evaluate the effect of RAB versus standard anesthesia care on the incidence of PNCD in adult patients undergoing major non-cardiac surgery.

EVIDENCE REVIEW

PubMed, EMBASE, Scopus, and the Cochrane Central Registers of Controlled Trials (CENTRAL) were searched for randomized controlled trials (RCTs) from 2017 until June 2022. The primary outcome was the incidence of PNCD within 1 month of surgery. A random-effects model with an inverse variance method was used to pool results, and OR and mean differences were calculated for dichotomous and continuous outcomes. Various exploratory subgroup analyses were performed to explore the possibility of the association between the various patient, technique, and surgery-related factors. Grading of Recommendation, Assessment, Development, and Evaluation guidelines were used to determine the certainty of evidence.

FINDINGS

Twenty-six RCTs comprizing 4414 patients were included. The RAB group was associated with a significant reduction in the incidence of PNCD with an OR of 0.46 (95% CI 0.35 to 0.59; p<0.00001; I2=28%) compared with the control group (moderate certainty). Subgroup analysis exhibited that the prophylactic efficacy of RAB persisted for both delirium and delayed neurocognitive recovery.

CONCLUSIONS

Current evidence suggests that supplemental RAB are beneficial in preventing PNCD in patients after major non-cardiac surgery.

PROSPERO REGISTRATION NUMBER

CRD42022338820.

Impact of Preoperative Sleep Disturbances on Postoperative Delirium in Patients with Intracranial Tumors: A Prospective, Observational, Cohort Study

Background

Postoperative delirium (POD) is prevalent in craniotomy patients and is associated with high mortality. Sleep disturbances are receiving increasing attention from clinicians as associated risk factors for postoperative complications. This study aimed to determine the impact of preoperative sleep disturbances on POD in craniotomy patients.

Methods

We recruited 130 patients undergoing elective craniotomy for intracranial tumors between May 1st and December 30th, 2022. Preoperative subjective sleep disturbances were assessed using the Pittsburgh Sleep Quality Index on the day of admission. We also measured objective perioperative sleep patterns using a dedicated sleep monitoring device 3 days before and 3 days after the surgery. POD was assessed twice daily using the Confusion Assessment Model for the Intensive Care Unit within the first week after craniotomy.

Results

Preoperative sleep disturbances were diagnosed in 49% of the study patients, and POD was diagnosed in 22% of all the study patients. Sleep disturbances were an independent risk factor for POD (OR: 2.709, 95% CI: 1.020-7.192, P = 0.045). Other risk factors for POD were age (OR: 3.038, 95% CI: 1.195-7.719, P = 0.020) and the duration of urinary catheterization (OR: 1.246, 95% CI: 1.025-1.513, P = 0.027). Perioperative sleep patterns (including sleep latency, deep sleep duration, frequency of awakenings, apnea-hypopnea index, and sleep efficiency) were significantly associated with POD.

Conclusion

This study demonstrated that preoperative sleep disturbances predispose patients undergoing craniotomy to POD, also inferred a correlation between perioperative sleep patterns and POD. The targeted screening and intervention specifically for sleep disturbances during the perioperative period are immensely required.

The Impact of Regional Nerve Blocks on Postoperative Delirium or Cognitive Dysfunction following Thoracic Surgery: A Systematic Review and Meta-Analysis

Regional nerve blocks (NBs) mitigate the occurrence of postoperative cognitive dysfunction (POCD) and postoperative delirium (POD) in adult patients undergoing thoracic surgery. This study aimed to determine the exact effect of NBs on POCD and POD. Electronic databases, including PubMed, EMBASE, CINAHL, Scopus, and Web of Science, were searched for studies. The primary outcome was the incidence of POD or POCD. The secondary outcome was pain scores assessed 24 and 48 h postoperatively. We calculated the log odds ratio (LOR) and standardized mean difference (SMD) with 95% confidence intervals (CIs). The LOR was converted to an odds ratio (OR). In the analysis of 1010 patients from seven randomized controlled trials, POD and POCD rates were 14.1% and 16.7%, respectively, in the NB group, and higher, at 27.3% and 35.2%, in the control group. NBs reduced the incidence of POD (OR, 0.44; 95%CI 0.30 to 0.64; p < 0.001; I2 = 0.00%) and POCD (OR, 0.43; 95%CI 0.24 to 0.76; p < 0.001; I2 = 0.00%). NBs reduced pain scores at 24 h (SMD, -2.60; 95%CI -3.90 to -1.30, p < 0.001; I2 = 97.68%) and 48 h (SMD, -1.80; 95%CI -3.18 to -0.41, p = 0.01; I2 = 98.14%) postoperatively. NBs mitigated the occurrence of POD and POCD in adult patients after thoracic surgery.

Effects of intravenous glucocorticoids on postoperative delirium in adult patients undergoing major surgery: a systematic review and meta-analysis with trial sequential analysis

BACKGROUND

The effects of intravenous glucocorticoids on postoperative delirium (POD) in adult patients undergoing major surgery remain controversial. Therefore, we conducted this meta-analysis to assess whether intravenous glucocorticoids can decrease POD incidence in the entire adult population undergoing major surgery and its association with patients age, type of surgery, and type of glucocorticoid.

METHODS

We searched the relevant literature published before November 3, 2023, through Cochrane Library, PubMed, Embase, and Web of Science. The primary outcome was POD incidence. The risk ratio for the primary outcome was calculated using the Mantel-Haenszel method. The secondary outcomes included 30-day mortality, length of hospital stay, ICU duration, mechanical ventilation duration, and occurrence of glucocorticoid-related adverse effects (e.g., infection and hyperglycemia). This meta-analysis was registered in PROSPERO: CRD42022345997.

RESULTS

We included eight randomized controlled studies involving 8972 patients. For the entire adult population undergoing major surgery, intravenous glucocorticoids reduced the POD incidence (risk ratio = 0.704, 95% confidence interval, 0.519-0.955; P = 0.024). However, subgroups defined by type of surgery showed differential effects of glucocorticoids on POD. Intravenous glucocorticoids can not reduce POD incidence in adult patients undergoing cardiac surgery (risk ratio = 0.961, 95% confidence interval, 0.769-1.202; P = 0.728), with firm evidence from trial sequential analysis. However, in major non-cardiac surgery, perioperative intravenous glucocorticoid reduced the incidence of POD (risk ratio = 0.491, 95% confidence interval, 0.338-0.714; P < 0.001), which warrants further studies due to inconclusive evidence by trial sequence analysis. In addition, the use of glucocorticoids may reduce the mechanical ventilation time (weighted mean difference, -1.350; 95% confidence interval, -1.846 to -0.854; P < 0.001) and ICU duration (weighted mean difference = -7.866; 95% confidence interval, -15.620 to -0.112; P = 0.047).

CONCLUSIONS

For the entire adult population undergoing major surgery, glucocorticoids reduced the POD incidence. However, the effects of glucocorticoids on POD appear to vary according to the type of surgery. In patients receiving major non-cardiac surgery, glucocorticoid may be an attractive drug in the prevention of POD, and further studies are needed to draw a definitive conclusion. In cardiac surgery, intravenous glucocorticoids have no such effect.

Incidence of delirium in older people with cancer: Systematic review and meta-analysis

PURPOSE

Delirium is a prevalent neuropsychiatric syndrome in older people with cancer. However, there are no meta-analyses assessing its incidence exclusively in this population. This study aims to assess the incidence proportion of delirium in older people with cancer in the hospital area.

METHODS

A systematic review and meta-analysis were carried out. MEDLINE, Scopus, and EBSCO were searched from inception to December 2021. PRISMA guidelines were followed. Inclusion criteria were original peer-reviewed studies with experimental (randomised controlled trials), observational, and cross-sectional designs assessing delirium older inpatients (≥65 years) with oncological diseases in medical and post-surgical hospital areas and using validated screening or diagnostic methods. A web-based system was used to manage the screening process. Study quality was assessed with Joanna Briggs Institute Critical Appraisal tools. The statistical analysis was performed in RevMan v5.4.0 (Cochrane Collaboration, Oxford, UK), using a random-effects model to calculate incidence and 95% confidence intervals (CIs).

RESULTS

Based on 37 included articles, the incidence proportion of delirium ranged from 3.8% to 61.4%, in a total of 11,847 older patients with cancer. Meta-analysis showed a pooled incidence of 22.6% (95% confidence interval 18.5%, 26.7%; I2 = 97%, p < 0.001). The main tools for detection were the Diagnostic Statistical Manual criteria and the Confusion Assessment Methods scale.

CONCLUSIONS

The incidence proportion of delirium in older inpatients with cancer is 22.6%. Incidence in the medical setting was higher than in the post-surgical areas. There is a need for high-quality studies examining delirium in older people with cancer.

Dynamic Nomogram for Predicting the Risk of Perioperative Neurocognitive Disorders in Adults

BACKGROUND

Simple and rapid tools for screening high-risk patients for perioperative neurocognitive disorders (PNDs) are urgently needed to improve patient outcomes. We developed an online tool with machine-learning algorithms using routine variables based on multicenter data.

METHODS

The entire dataset was composed of 49,768 surgical patients from 3 representative academic hospitals in China. Surgical patients older than 45 years, those undergoing general anesthesia, and those without a history of PND were enrolled. When the patient's discharge diagnosis was PND, the patient was in the PND group. Patients in the non-PND group were randomly extracted from the big data platform according to the surgical type, age, and source of data in the PND group with a ratio of 3:1. After data preprocessing and feature selection, general linear model (GLM), artificial neural network (ANN), and naive Bayes (NB) were used for model development and evaluation. Model performance was evaluated by the area under the receiver operating characteristic curve (ROCAUC), the area under the precision-recall curve (PRAUC), the Brier score, the index of prediction accuracy (IPA), sensitivity, specificity, etc. The model was also externally validated on the multiparameter intelligent monitoring in intensive care (MIMIC) Ⅳ database. Afterward, we developed an online visualization tool to preoperatively predict patients' risk of developing PND based on the models with the best performance.

RESULTS

A total of 1051 patients (242 PND and 809 non-PND) and 2884 patients (6.2% patients with PND) were analyzed on multicenter data (model development, test [internal validation], external validation-1) and MIMIC Ⅳ dataset (external validation-2). The model performance based on GLM was much better than that based on ANN and NB. The best-performing GLM model on validation-1 dataset achieved ROCAUC (0.874; 95% confidence interval [CI], 0.833-0.915), PRAUC (0.685; 95% CI, 0.584-0.786), sensitivity (72.6%; 95% CI, 61.4%-81.5%), specificity (84.4%; 95% CI, 79.3%-88.4%), Brier score (0.131), and IPA (44.7%), and of which the ROCAUC (0.761, 95% CI, 0.712-0.809), the PRAUC (0.475, 95% CI, 0.370-0.581), Brier score (0.053), and IPA (76.8%) on validation-2 dataset. Afterward, we developed an online tool (https://pnd-predictive-model-dynnom.shinyapps.io/ DynNomapp/) with 10 routine variables for preoperatively screening high-risk patients.

CONCLUSIONS

We developed a simple and rapid online tool to preoperatively screen patients' risk of PND using GLM based on multicenter data, which may help medical staff's decision-making regarding perioperative management strategies to improve patient outcomes.

Prophylactic effect of exogenous melatonin and melatonin receptor agonists on postoperative delirium in elderly patients: a systemic review and meta-analysis of randomized controlled trials

BACKGROUND

The prophylactic effect of exogenous melatonin and melatonin receptor agonists (MMRAs) on postoperative delirium (POD) in elderly patients remains controversial.

OBJECTIVE

This study aimed to assess the prophylactic effect of MMRAs on POD by conducting a systemic review and meta-analysis of randomized controlled trials (RCTs).

METHODS

We systematically searched four electronic databases including PubMed, Web of Science, Cochrane Library, and Embase for the eligible studies up to February 28, 2023. The Cochrane risk of bias tool was used for assessing the risk of bias in the included RCTs. The occurrence of POD was the primary outcome. The quality of evidence was evaluated by Grading of Recommendations Assessment, Development, and Evaluation.

RESULTS

A total of 11 RCTs comprising patients (MMRA group: 777 patients and placebo group: 781 patients) were included. The results of the meta-analysis showed that the MMRA group had a lower occurrence of POD than the placebo group (risk ratio = 0.70, 95% confidence interval: 0.51-0.97, P < 0.05, I2 = 59%). The subgroup analysis showed that melatonin significantly reduced the occurrence of POD (moderate-quality evidence), whereas ramelteon and tryptophan had no significant impact (moderate-quality evidence).

CONCLUSION

Existing evidence suggested that perioperative use of melatonin can prevent POD in elderly patients.

Incidence and risk factors for postoperative delirium after head and neck cancer surgery: an updated meta-analysis

BACKGROUND

Postoperative delirium (POD) is a frequent neurologic dysfunction that often leads to more negative outcomes. Early identification of patients who are vulnerable to POD and early implementation of appropriate management strategies could decrease its occurrence and improve patient prognosis. Therefore, this meta-analysis comprehensively and quantitatively summarized the prevalence and related predictive factors of POD in head and neck cancer surgical patients.

METHODS

PubMed, Embase, and Cochrane Library were searched for observational studies that reported the prevalence and risk factors for POD after head and neck cancer surgery and were published from their inception until December 31, 2022. Two reviewers independently selected qualified articles and extracted data. The qualities of related papers were assessed using the Newcastle-Ottawa scale (NOS). RevMan 5.3 and Stata 15.0 were applied to analysis the data and conduct the meta-analysis.

RESULTS

Sixteen observational studies with 3289 inpatients who underwent head and neck cancer surgery were included in this review. The occurrence of POD ranged from 4.2 to 36.9%, with a pooled incidence of 20% (95% CI 15-24%, I2 = 93.2%). The results of this pooled analysis demonstrated that the statistically significant risk factors for POD were increased age (OR: 1.05, 95% CI: 1.03-1.07, P < 0.001), age > 75 years (OR: 6.52, 95% CI: 3.07-13.87, P < 0.001), male sex (OR: 2.29, 95% CI: 1.06-4.97, P = 0.04), higher American Society of Anesthesiologists grade (OR: 2.19, 95% CI: 1.44-3.33, P < 0.001), diabetes mellitus (OR: 2.73, 95% CI: 1.24-6.01, P = 0.01), and history of smoking (OR: 2.74, 95% CI: 1.13-6.65, P = 0.03).

CONCLUSIONS

POD frequently occurs after head and neck cancer surgery. Several independent predictors for POD were identified, which might contribute to identifying patients at high risk for POD and play a prominent role in preventing POD in patients following head and neck cancer surgery.

Effect of postoperative delirium after cardiovascular surgery on 5-year mortality

INTRODUCTION

Postoperative delirium is a common complication after cardiovascular surgery. A meta-analysis revealed that postoperative delirium was associated with cognitive decline and dementia, which may affect long-term mortality. However, few studies have reported the association between postoperative delirium after cardiovascular surgery and long-term postoperative mortality. Therefore, we investigated the effect of postoperative delirium on 5-year survival rates of patients who underwent cardiovascular surgery.

METHODS

We retrospectively reviewed the records of patients who underwent cardiovascular surgery with cardiopulmonary bypass from January 2016 to December 2019. Postoperative delirium was defined as an Intensive Care Delirium Screening score ≥ 3, which might include subclinical delirium. Cox proportional hazards modeling was performed to assess the association between postoperative delirium and mortality. Postoperative mortality in patients with and without delirium was assessed using the Kaplan-Meier method and compared using the log-rank test.

RESULTS

Postoperative delirium was observed in 562 (31.9%) of 1731 patients. There were more elderly patients, more emergent surgery procedures, longer operative time, and larger transfusion volume in the postoperative delirium group. Cox regression analyses showed that delirium (hazard ratio (HR), 1.501; 95% confidence interval (CI), 1.053-2.140; p = 0.025) and emergent surgery (HR, 3.380; 95% CI, 2.231-5.122; p < 0.001) are significantly associated with 5-year mortality. Among patients who underwent elective surgery, postoperative delirium (HR, 1.987; 95% CI, 1.135-3.481; p = 0.016) is significantly associated with 5-year mortality. Kaplan-Meier survival analysis revealed that patients with postoperative delirium had significantly higher 5-year mortality.

CONCLUSIONS

Patients with postoperative delirium after cardiovascular surgery have significantly higher 5-year mortality.

Multivariable model of postoperative delirium in cardiac surgery patients: proteomic and demographic contributions

Background

Delirium following cardiac surgery is common, morbid, and costly, but may be prevented with risk stratification and targeted intervention. Preoperative protein signatures may identify patients at increased risk for worse postoperative outcomes, including delirium. In this study, we aimed to identify plasma protein biomarkers and develop a predictive model for postoperative delirium in older patients undergoing cardiac surgery, while also uncovering possible pathophysiological mechanisms.

Methods

SOMAscan analysis of 1,305 proteins in the plasma from 57 older adults undergoing cardiac surgery requiring cardiopulmonary bypass was conducted to define delirium-specific protein signatures at baseline (PREOP) and postoperative day 2 (POD2). Selected proteins were validated in 115 patients using the ELLA multiplex immunoassay platform. Proteins were combined with clinical and demographic variables to build multivariable models that estimate the risk of postoperative delirium and bring light to the underlying pathophysiology.

Results

A total of 115 and 85 proteins from SOMAscan analyses were found altered in delirious patients at PREOP and POD2, respectively (p<0.05). Using four criteria including associations with surgery, delirium, and biological plausibility, 12 biomarker candidates (Tukey's fold change (|tFC|)>1.4, Benjamini-Hochberg (BH)-p<0.01) were selected for ELLA multiplex validation. Eight proteins were significantly altered at PREOP, and seven proteins at POD2 (p<0.05), in patients who developed postoperative delirium compared to non-delirious patients. Statistical analyses of model fit resulted in the selection of a combination of age, sex, and three proteins (angiopoietin-2 (ANGPT2); C-C motif chemokine 5 (CCL5); and metalloproteinase inhibitor 1 (TIMP1); AUC=0.829) as the best performing predictive model for delirium at PREOP. The delirium-associated proteins identified as biomarker candidates are involved with inflammation, glial dysfunction, vascularization, and hemostasis, highlighting the multifactorial pathophysiology of delirium.

Conclusion

Our study proposes a model of postoperative delirium that includes a combination of older age, female sex, and altered levels of three proteins. Our results support the identification of patients at higher risk of developing postoperative delirium after cardiac surgery and provide insights on the underlying pathophysiology. ClinicalTrials.gov ( NCT02546765 ).

Impact of paravertebral block on perioperative neurocognitive disorder: a systematic review and meta-analysis of randomized controlled trials

Objective

To investigate whether paravertebral block reduces postoperative delirium (POD)/delayed neurocognitive recovery (DNR) in adults after major surgery with general anesthesia.

Methods

For this systematic review and meta-analysis, we searched online databases PubMed, EMBASE, CENTRAL, and Web of Science till March 19th, 2023 to examine studies which use paravertebral block (PVB) for perioperative neurocognitive disorder. Primary and secondary outcomes were identified for the incidence of perioperative neurocognitive disorder. We did not restrict the follow-up duration of the included studies. Statistical analysis was performed to calculate mean difference (MD), Odd ratios (OR) and CI between RCTs. The quality of the evidence was assessed with the Cochrane risk of bias tool. The registration number of the study in PROSPERO is CRD42023409502. PROSPERO is an international database of prospectively registered systematic reviews. Registration provides transparency in the review process and it helps counter publication bias.

Results

Total 1,225 patients from 9 RCTs were analyzed. The incidence of POD [Odds Ratio (OR) = 0.48, 95% CI 0.32, 0.72; p = 0.0004; I2 = 0%] and DNR [OR = 0.32, 95% CI 0.13, 0.80; p = 0.01; I2 = 0%] were significantly reduced in PVB group. The analysis showed no significant differences in postoperative MMSE scores [MD = 0.50, 95% CI -2.14, 3.15; p = 0.71; I2 = 98%]. Paravertebral block analgesia reduces pain scores and/or opioid use after surgery. Additionally, blood pressure was significantly lower in the PVB group, intraoperatively [MD = -15.50, 95% CI -20.71, -10.28; p < 0.001; I2 = 12%] and postoperatively [MD = -5.34, 95% CI -10.65, -0.03 p = 0.05; I2 = 36%]. Finally, PVB group had significantly shorter hospital stays [MD = -0.86, 95% CI -1.13, -0.59; p < 0.001; I2 = 0%].

Conclusion

Paravertebral block analgesia may prevent perioperative POD/DNR in patients undergoing major surgery. Further research with large sample sizes is required to confirm its effectiveness.

Machine learning for prediction of delirium in patients with extensive burns after surgery

AIMS

Machine learning-based identification of key variables and prediction of postoperative delirium in patients with extensive burns.

METHODS

Five hundred and eighteen patients with extensive burns who underwent surgery were included and randomly divided into a training set, a validation set, and a testing set. Multifactorial logistic regression analysis was used to screen for significant variables. Nine prediction models were constructed in the training and validation sets (80% of dataset). The testing set (20% of dataset) was used to further evaluate the model. The area under the receiver operating curve (AUROC) was used to compare model performance. SHapley Additive exPlanations (SHAP) was used to interpret the best one and to externally validate it in another large tertiary hospital.

RESULTS

Seven variables were used in the development of nine prediction models: physical restraint, diabetes, sex, preoperative hemoglobin, acute physiological and chronic health assessment, time in the Burn Intensive Care Unit and total body surface area. Random Forest (RF) outperformed the other eight models in terms of predictive performance (ROC:84.00%) When external validation was performed, RF performed well (accuracy: 77.12%, sensitivity: 67.74% and specificity: 80.46%).

CONCLUSION

The first machine learning-based delirium prediction model for patients with extensive burns was successfully developed and validated. High-risk patients for delirium can be effectively identified and targeted interventions can be made to reduce the incidence of delirium.

Risk prediction models for postoperative delirium in elderly patients with hip fracture: a systematic review

Objectives

To systematically evaluate the risk prediction models for postoperative delirium in older adult hip fracture patients.

Methods

Risk prediction models for postoperative delirium in older adult hip fracture patients were collected from the Cochrane Library, PubMed, Web of Science, and Ovid via the internet, covering studies from the establishment of the databases to March 15, 2023. Two researchers independently screened the literature, extracted data, and used Stata 13.0 for meta-analysis of predictive factors and the Prediction Model Risk of Bias Assessment Tool (PROBAST) to evaluate the risk prediction models for postoperative delirium in older adult hip fracture patients, evaluated the predictive performance.

Results

This analysis included eight studies. Six studies used internal validation to assess the predictive models, while one combined both internal and external validation. The Area Under Curve (AUC) for the models ranged from 0.67 to 0.79. The most common predictors were preoperative dementia or dementia history (OR = 3.123, 95% CI 2.108-4.626, p < 0.001), American Society of Anesthesiologists (ASA) classification (OR = 2.343, 95% CI 1.146-4.789, p < 0.05), and age (OR = 1.615, 95% CI 1.387-1.880, p < 0.001). This meta-analysis shows that these were independent risk factors for postoperative delirium in older adult patients with hip fracture.

Conclusion

Research on the risk prediction models for postoperative delirium in older adult hip fracture patients is still in the developmental stage. The predictive performance of some of the established models achieve expectation and the applicable risk of all models is low, but there are also problems such as high risk of bias and lack of external validation. Medical professionals should select existing models and validate and optimize them with large samples from multiple centers according to their actual situation. It is more recommended to carry out a large sample of prospective studies to build prediction models.

Systematic review registration

The protocol for this systematic review was published in the International Prospective Register of Systematic Reviews (PROSPERO) under the registered number CRD42022365258.

Frailty-originated early rehabilitation reduces postoperative delirium in brain tumor patients: Results from a prospective randomized study

Objective

To investigate the impact of frailty-originated, evidence-based early activity training on postoperative delirium in patients who have undergone brain tumor resection.

Methods

A randomized controlled trial was conducted at the Second Affiliated Hospital of Zhejiang University School of Medicine, from July 2019 to June 2020. Data on the patients' general information, incidence and duration of delirium, duration of hospital stay, and activities of daily living were collected. From the first day after surgery, the patients were randomly assigned to either the traditional care group or the frailty-originated rehabilitation towards intracranial tumors using distinct evidence (FORTITUDE) group. Non-parametric, chi-square, and log-rank tests were used to compare the onset time and duration of postoperative delirium and activities of daily living performed by the participants between the two groups.

Results

In total, 291 patients, 150 and 141 in the control group and FORTITUDE group, respectively, participated in the study. Patients in the FORTITUDE group had a lower incidence of postoperative delirium (15.6% vs. 28.7%, P ​= ​0.007), delayed onset of delirium (Z ​= ​-2.108, P ​= ​0.035), shorter duration of postoperative delirium (χ² ​= ​26.67, P ​< ​0.001), shorter hospital stay (Z ​= ​-2.037, P ​= ​0.042), and higher scores in the activities of daily living one week (Z ​= ​-2.304, P ​= ​0.021) and one month (Z ​= ​-2.724, P ​= ​0.006) after surgery than in the control group.

Conclusions

The FORTITUDE program was safe and effective in reducing the incidence and duration of postoperative delirium and improving the quality of life of patients who underwent brain tumor resection.

Modifiable risk factors for post-operative delirium in older adults undergoing major non-cardiac elective surgery: a multi-centre, trainee delivered observational cohort feasibility study and trainee survey

BACKGROUND

Post-operative delirium (POD) is an acute brain failure which may occur following major surgery, with serious implications for participants and caregivers. Evidence regarding optimal anaesthetic management for older participants at higher risk of POD is conflicting. We conducted a feasibility study of our protocol in 5 centres to guide sample size estimation and inform future recruitment strategies for a larger cohort study.

METHODS

Participants aged over 65 and scheduled for major surgery were recruited. They were assessed pre-operatively for delirium, cognitive impairment, depression, comorbidity, activity levels and alcohol use. Details of management during surgery, all medications and complications were recorded by a trainee-led research team. Participants were assessed for delirium in the immediate recovery period and then on post-operative days 1-4 using the 4 question attention test (4AT) with complications assessed at day 4 using the post-operative morbidity survey (POMS). Primary outcomes were the incident rates of POD. Secondary outcomes were number of eligible patients, recruitment rates and retention rates throughout the study, time required for data collection, preoperative risk factors assessment and daily postoperative delirium assessments. Also to assess the added value of employing the regional trainee research network (INCARNNET) to deliver the study. Specifically, what proportion of patient consent, data collection and post-operative testing is performed by anaesthesia trainees from this group, especially the success of weekend delirium assessment by trainees? A survey was completed at the end of the study by the trainees involved regarding their involvement in the study.

RESULTS

Ninety-five participants were recruited, of whom 93 completed the study. Overall, POD occurred in 9 patients. Of these, three were detected in recovery and six on post-op days 1-4. Median length of stay was 6 days. Recruitment rates were high in all but one site. 59 (62%) participants were consented by trainees and 189 (63%) of post op delirium assessments were performed by trainees. A total of six patients declined the study (in a follow up survey of trainees). Pre-existing cognitive impairment, depression and problem drinking were detected in 4(4.3%), 3(3.2%) and 5(5.37%) participants, respectively. Co-morbidity was common with 55(59%) in class three or four of the geriatric index of morbidity. Overall, from a total of 641 data points, levels of missing data were as follows, site A = 9.3%, B = 13.5%, C = 15.4%, D = 10.9%, E = 11.1% (data could not be completed retrospectively).

CONCLUSIONS

A multi-centre observational cohort study of delirium carried out by UK trainee anaesthetists is feasible. Patients are content to undergo day of surgery consent and multiple short questionnaires pre-operatively. Proposed data, especially pharmacological, should be carefully considered for their relevance to modifiable mechanisms that can lead to POD. Future research to enable prognostic modelling of POD should involve large scale cohort studies of enriched populations to capture a higher POD incidence. POD remains a common complication in older persons undergoing major surgery in the UK and studies of interventions are urgently needed.

TRIAL REGISTRATION

All methods were carried out in accordance with relevant guidelines and regulations. The study was retrospectively registered with ISRCTN94663125 on 07/02/2018.

[Postoperative Delirium in Patients on Cardiopulmonary Bypass for Cardiovascular Surgeries: Incidence and Influencing Factors]

Objective

To investigate the incidence and influencing factors of postoperative delirium (POD) and subsyndromal delirium (SSD) in patients connected to cardiopulmonary bypass during cardiovascular surgeries.

Methods

We collected the general data and the data for the perioperative hematological, physiological, and biochemical indicators and the surgical and therapeutic conditions of patients connected to cardiopulmonary bypass during the course of cardiovascular surgeries conducted at a tertiary-care hospital in Hubei province between May 2022 and September 2022. The outcome indicators, including the incidence of POD and SSD, were assessed with the Nursing Delirium Screening Scale (Nu-DESC). Multinomial logistic regression was performed to analyze the influencing factors of patients with different statuses of POD and SSD.

Results

Among the 202 patients, the incidence of SSD, SSD progressing to POD, and no POD or SSD (ND) progressing to POD were 13.4%, 6.4%, and 34.2%, respectively. Regression analysis showed that, with ND patients as the controls, the influencing factors for SSD were preoperative blood glucose (odds ratio [ OR]=0.38, 95% confidence interval [ CI]: 0.19-0.76), intraoperative platelet transfusion ( OR=0.37, 95% CI: 0.15-0.92), intraoperative etomidate ( OR=0.93, 95% CI: 0.87-0.98), and postoperative total bilirubin level ( OR=1.04, 95% CI: 1.01-1.07). For the progression of SSD to POD, the influencing factors were age ( OR=1.09, 95% CI: 1.01-1.17), ASA classification of IV and above ( OR=10.72, 95% CI: 1.85-62.08), intraoperative dexmedetomidine ( OR=1.01, 95% CI: 1.003-1.02), and the duration of mechanical ventilation ( OR=1.04, 95% CI: 1.01-1.07). For the progression of ND to POD, the influencing factors were age ( OR=1.06, 95% CI: 1.02-1.10), middle or high school education ( OR=0.35, 95% CI: 0.15-0.83), and the duration of mechanical ventilation ( OR=1.04, 95% CI: 1.01-1.07).

Conclusion

Age, education, ASA classification, preoperative blood glucose, intraoperative platelet transfusion, intraoperative etomidate, intraoperative dexmedetomidine, postoperative total bilirubin, and the duration of mechanical ventilation are influencing factors for different statuses of POD and SSD among patients connected to cardiopulmonary bypass when they are undergoing cardiovascular surgeries. The influencing factors vary across groups of patients with different statuses of POD and SSD. Therefore, we should accurately assess the risk factors of patients with different statuses of POD and SSD and carry out corresponding interventions, thereby preventing or reducing the occurrence of POD and SSD, and ultimately promoting enhanced recovery after surgery.

A predictive scoring system for postoperative delirium in the elderly patients with intertrochanteric fracture

OBJECTIVE

To establish a scoring system to predict the postoperative delirium in elderly patients with intertrochanteric fracture.

MATERIALS AND METHODS

We retrospectively reviewed 159 elderly patients with a diagnosis of intertrochanteric fracture and underwent closed reduction and intramedullary nail fixation, and then divided them into two groups including the delirium group (23 cases) or non-delirium group (136 cases) in our hospital from January 2017 to December 2019. The following clinical characteristics were recorded and analyzed: age, gender, fracture classification, body mass index (BMI), history of diabetes mellitus, history of stroke, preoperative albumin, preoperative hemoglobin (Hb), preoperative arterial partial pressure of oxygen (PaO₂), time between admission and surgery, lower limb thrombosis, American Society of Anesthesiologists (ASA) grade, operative time, operative blood loss, and intraoperative blood transfusion. The prevalence of these clinical characteristics in delirium group was evaluated, and the scoring system was established using logistic regression analysis. The performance of the scoring system was also prospectively validated.

RESULTS

The predictive scoring system was based on five clinical characteristics confirmed as significant predictors of postoperative delirium, namely, age > 75 years, history of stroke, preoperative Hb ≤ 100 g/L, preoperative PaO₂ ≤ 60 mmHg, and time between admission to surgery > 3 days. Delirium group showed a significant higher score than non-delirium (6.26 vs. 2.29, P < 0.001), and the optimal cut-off value for the scoring system was 4 points. The sensitivity and specificity of the scoring system for predicting postoperative delirium were 82.61% and 81.62% in derivation set, respectively, and 72.71% and 75.00% in validation set.

CONCLUSION

The predictive scoring system confirmed with achieve satisfactory sensitivity and specificity in predicting postoperative delirium in the elderly with intertrochanteric fracture. The risk of postoperative delirium in patients with the score of 5 to 11 is high, while the score of 0 to 4 is low.

Development and validation of an international preoperative risk assessment model for postoperative delirium

BACKGROUND

Postoperative delirium (POD) is a frequent complication in older adults, characterised by disturbances in attention, awareness and cognition, and associated with prolonged hospitalisation, poor functional recovery, cognitive decline, long-term dementia and increased mortality. Early identification of patients at risk of POD can considerably aid prevention.

METHODS

We have developed a preoperative POD risk prediction algorithm using data from eight studies identified during a systematic review and providing individual-level data. Ten-fold cross-validation was used for predictor selection and internal validation of the final penalised logistic regression model. The external validation used data from university hospitals in Switzerland and Germany.

RESULTS

Development included 2,250 surgical (excluding cardiac and intracranial) patients 60 years of age or older, 444 of whom developed POD. The final model included age, body mass index, American Society of Anaesthesiologists (ASA) score, history of delirium, cognitive impairment, medications, optional C-reactive protein (CRP), surgical risk and whether the operation is a laparotomy/thoracotomy. At internal validation, the algorithm had an AUC of 0.80 (95% CI: 0.77-0.82) with CRP and 0.79 (95% CI: 0.77-0.82) without CRP. The external validation consisted of 359 patients, 87 of whom developed POD. The external validation yielded an AUC of 0.74 (95% CI: 0.68-0.80).

CONCLUSIONS

The algorithm is named PIPRA (Pre-Interventional Preventive Risk Assessment), has European conformity (ce) certification, is available at http://pipra.ch/ and is accepted for clinical use. It can be used to optimise patient care and prioritise interventions for vulnerable patients and presents an effective way to implement POD prevention strategies in clinical practice.

[Postoperative delirium in the recovery room]

Postoperative delirium during emergence from anesthesia is the most frequent neuropsychiatric complication in the post-anesthesia care unit. In addition to increased medical and especially nursing care efforts, affected patients are threatened with delayed rehabilitation with a longer hospital stay and an increased mortality. It is therefore essential to identify risk factors at an early stage and to implement preventive measures; however, should a postoperative delirium occur in the post-anesthesia care unit despite the use of these preventive measures, it should be detected and treated at an early stage using suitable screening procedures. In this context, working instructions for delirium prophylaxis and standardized test procedures for detection of delirium have been shown to be useful. An additional drug treatment can be indicated when all nonpharmacological options have been exhausted.

Knowledge, attitude, and practice regarding postoperative delirium among cardiac surgery nurses: A cross-sectional multi-centre study

AIMS AND OBJECTIVES

To examine knowledge, attitude, and practice regarding postoperative delirium and the relationships among cardiac surgery nurses in China.

BACKGROUND

Postoperative delirium is a prevalent and devastating complication following cardiac surgery. Nurses play a part in multi-disciplinary collaboration for preventing and managing postoperative delirium, of whom knowledge, attitude, and practice are essential.

DESIGN

A cross-sectional multi-centre study.

METHODS

Nurses from cardiac surgery wards and intensive care units of five tertiary hospitals in Wuhan, Hubei Province, China were enrolled. Data were gathered online using a self-administered questionnaire. Student's t-test, or analysis of variance, or non-parametric tests were performed to compare differences across groups. Bootstrapping mediation analysis was conducted to examine the relationship between knowledge, attitude, and practice. The STROBE checklist was used for the reporting of this study.

RESULTS

Of 429 nurses, a moderate level of knowledge and high levels of attitude and practice regarding postoperative delirium were revealed. Nurses with higher education, higher academic title, 5-10 years of practice in nursing and cardiac surgery nursing exhibited increased knowledge. With advanced age, practice in a specialised hospital, and training experience, nurses reported a better degree of practice. Attitude played a full mediating effect in the relationship between knowledge and practice, accounting for 81.82% of the total effects.

CONCLUSIONS

Knowledge, attitude, and practice regarding postoperative delirium are promising among Chinese cardiac surgery nurses, with knowledge of screening tools and perioperative nonpharmacological interventions and practice of screening in need of enhancement. Attitudes act as an intermediary between knowledge and practice regarding postoperative delirium.

RELEVANCE TO CLINICAL PRACTICE

Innovative and stratified in-service education is warranted to address knowledge enhancement. Meanwhile, organisations are suggested to make efforts to foster nurses' positive attitudes, particularly in creating a favourable culture and developing institutional protocols for postoperative delirium management to improve practice.

NO PATIENT OR PUBLIC CONTRIBUTION

This study is focused on cardiac surgery nurses' knowledge, attitude, and practice regarding postoperative delirium, and the research questions and design are from clinical nursing practice, literature review, and expert panel review, in which the patient or public is temporarily not involved.

Relationship Between Delirium Development and Its Causative Factors in the Intensive Care Unit After Cardiac Surgery

Background

Delirium is a clinical symptom that can have serious side effects in patients, and it develops acutely and shows reversibility. Postoperative delirium is an important neuropsychological complication after surgery that directly or indirectly affects patients.

Cardiac surgery increases the risk of delirium due to the complexity of surgical procedures, use of intraoperative and postoperative anesthetics and other pharmacologic agents, and possible postoperative complications. This study aims to determine the relationship between the development of delirium and its causative factors after cardiac surgery and its associated postoperative complications, and identify the high-relevance risk factors of postoperative delirium.

Methods

The participants comprised 730 patients who were admitted to the intensive care unit and underwent cardiac surgery. The collected data included 19 risk factors based on the patients' medical information records. As a delirium diagnostic tool, we used the Intensive Care Delirium Screening Checklist, with four or more points indicating delirium. For statistical analysis, the dependent variables were determined based on the presence or absence of delirium, while the independent variables were determined based on the risk factors of delirium. A t-test, χ² test, and logistic regression analysis were performed on risk factors between the two groups-the delirium group and no delirium group.

Results

Postoperative delirium was observed in 126 (17.3%) of 730 patients after cardiac surgery. Postoperative complications were more common in the delirium group. Independent risk factors associated with postoperative delirium were identified in 7 of the 12 factors.

Conclusion

As cardiac surgery is invasive and affects the development and severity of delirium, efforts and intervention methods are necessary to predict the risk factors for the development of delirium before surgery, and to prevent its occurrence after surgery. In the future, it is necessary to further investigate factors associated with delirium that can be directly intervened.

Relationship between body mass index and risk of delirium in an intensive care unit

OBJECTIVE

Delirium in the intensive care unit (ICU) is a common and critical condition that leads to poor prognosis in older patients, but the association between body mass index (BMI) and the incidence of delirium remains unclear.

METHODS

We retrospectively analyzed 5,622 patients admitted to the ICU of a tertiary referral hospital between 2013 and 2022. We collected sociodemographic data, vital signs, laboratory results, and delirium scale scores. We subdivided the patients into four categories: underweight (<18.5 kg/m²), normal weight (18.5-22.9 kg/m²), overweight (23-24.9 kg/m²), and obese (>25 kg/m²). The primary outcome was the incidence of delirium according to the BMI categories. We performed multivariable logistic regression analysis, adjusted for sex, age, past smoking and alcohol history, benzodiazepine use, and laboratory abnormalities.

RESULTS

Among the 5,622 patients in the ICU (mean age, 72.9 years; male, 60.1%; mean BMI, 24.2 kg/m²⁾, the incidence of delirium was 19.0% (1,069 patients). The mean modified incidence of delirium was higher among underweight patients (odds ratio [OR]=1.51, confidence interval [CI]=1.07-2.12, p = 0.02) than among normal-weight patients. Overweight and obese status were not independently associated with delirium (OR=0.90, CI=0.70-1.17, p = 0.43; OR= 0.97; CI=0.77-1.21, p = 0.78, respectively). The area under the receiver-operating characteristic curve of the multivariable logistic regression model was 0.71 (95% CI=0.69-0.73).

CONCLUSIONS

Underweight status is an independent risk factor for delirium in the ICU. Additional caution is required when evaluating underweight patients for delirium. Obese or overweight status are not associated with delirium, providing evidence for the obesity paradox.

Preoperative frailty vs. cognitive impairment: Which one matters most for postoperative delirium among older adults with cancer?

INTRODUCTION

Limited data are available to explore the association between preoperative frailty and cognitive impairment with postoperative delirium among older adults with cancer. We explored this association in a single Comprehensive Cancer Center where postoperative delirium and frailty are assessed in routine care using the Confusion Assessment Method (CAM) and Memorial Sloan Kettering Frailty Index (MSK-FI), respectively.

MATERIALS AND METHODS

Retrospective study on patients with cancer, aged 65+, who underwent surgery from April 2018 to March 2019 with hospital stay ≥1 day. We used logistic regression with postoperative delirium as the outcome, primary predictor MSK-FI, adjusted for age, operative time, and preoperative albumin. As the MSK-FI includes a component related to cognitive impairment, we additionally evaluated the impact of this component, separately from the rest of the score, on the association between frailty and postoperative delirium.

RESULTS

Among 1,257 patients with available MSK-FI and CAM measures, 47 patients (3.7%) had postoperative delirium. Increased frailty was associated with increased risk of postoperative delirium (odds ratio [OR] 1.51; 95% confidence interval [CI] 1.26, 1.81; p < 0.001). However, this was largely related to the effect of cognitive impairment (OR 15.29; 95% CI 7.18; 32.56; p < 0.001). In patients with cognitive impairment, the association between frailty and postoperative delirium was not significant (OR 0.97; 95% CI 0.65, 1.44; p-value = 0.9), as having cognitive impairment put patients at high risk for postoperative delirium even without taking into account the other components of the MSK-FI. While the association between frailty and postoperative delirium in patients with intact cognitive function was statistically significant (OR 1.58; 95% CI 1.27, 1.96; p < 0.001), it was not clinically meaningful, particularly considering the low risk of delirium among patients with intact cognitive function (e.g., 1.3% vs 3.2% for MSK-FI 1 vs 3).

DISCUSSION

Cognitive function should be a greater focus than frailty, as measured by the MSK-FI, in preoperative assessment for the prediction of postoperative delirium.

The Effect of Peripheral Nerve Block on Postoperative Delirium in Older Adults Undergoing Hip Surgery: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

This meta-analysis aimed to determine whether peripheral nerve blocks (PNB) reduce postoperative delirium (POD) in elderly patients undergoing hip surgery. This study was registered in the International Prospective Register of Systematic Reviews (PROSPERO; CRD42022328320). The PubMed, EMBASE, Web of Science, and Cochrane Library databases were searched for randomized controlled trials (RCTs) on 26 April 2022. A total of 19 RCTs with 1977 participants were included. Perioperative PNB lowered the POD incidence on the third postoperative day (OR: 0.59, 95% CI [0.40 to 0.87], p = 0.007, I² = 35%), in patients without underlying cognitive impairment (OR: 0.47, 95% CI [0.30 to 0.74], p = 0.001, I² = 30%), and when a fascia iliaca compartment block (OR: 0.58, 95% CI [0.37 to 0.91], p = 0.02, I² = 0%) or a femoral nerve block (OR: 0.33, 95% CI [0.11 to 0.99], p = 0.05, I² = 66%) were performed. The pain score was also reduced (SMD: -0.83, 95% CI [-1.36 to -0.30], p = 0.002, I² = 95%) after PNB. Perioperative PNB can lower the POD incidence and pain scores up to the third postoperative day. However, considering the wide variety of PNBs performed, more trials are needed to identify the effects of each PNB on POD.

Altered Tryptophan-Kynurenine Pathway in Delirium: A Review of the Current Literature

Delirium, a common form of acute brain dysfunction, is associated with increased morbidity and mortality, especially in older patients. The underlying pathophysiology of delirium is not clearly understood, but acute systemic inflammation is known to drive delirium in cases of acute illnesses, such as sepsis, trauma, and surgery. Based on psychomotor presentations, delirium has three main subtypes, such as hypoactive, hyperactive, and mixed subtype. There are similarities in the initial presentation of delirium with depression and dementia, especially in the hypoactive subtype. Hence, patients with hypoactive delirium are frequently misdiagnosed. The altered kynurenine pathway (KP) is a promising molecular pathway implicated in the pathogenesis of delirium. The KP is highly regulated in the immune system and influences neurological functions. The activation of indoleamine 2,3-dioxygenase, and specific KP neuroactive metabolites, such as quinolinic acid and kynurenic acid, could play a role in the event of delirium. Here, we collectively describe the roles of the KP and speculate on its relevance in delirium.