Risk factors for postoperative delirium and subsyndromal delirium in older patients in the surgical ward: A prospective observational study

Electroencephalography-Guided Anesthesia and Delirium in Older Adults After Cardiac Surgery: The ENGAGES-Canada Randomized Clinical Trial

Importance

Intraoperative electroencephalogram (EEG) waveform suppression, suggesting excessive general anesthesia, has been associated with postoperative delirium.

Objective

To assess whether EEG-guided anesthesia decreases the incidence of delirium after cardiac surgery.

Design, Setting, and Participants

Randomized, parallel-group clinical trial of 1140 adults 60 years or older undergoing cardiac surgery at 4 Canadian hospitals. Recruitment was from December 2016 to February 2022, with follow-up until February 2023.

Interventions

Patients were randomized in a 1:1 ratio (stratified by hospital) to receive EEG-guided anesthesia (n = 567) or usual care (n = 573). Patients and those assessing outcomes were blinded to group assignment.

Main Outcomes and Measures

The primary outcome was delirium during postoperative days 1 through 5. Intraoperative measures included anesthetic concentration and EEG suppression time. Secondary outcomes included intensive care and hospital length of stay. Serious adverse events included intraoperative awareness, medical complications, and 30-day mortality.

Results

Of 1140 randomized patients (median [IQR] age, 70 [65-75] years; 282 [24.7%] women), 1131 (99.2%) were assessed for the primary outcome. Delirium during postoperative days 1 to 5 occurred in 102 of 562 patients (18.15%) in the EEG-guided group and 103 of 569 patients (18.10%) in the usual care group (difference, 0.05% [95% CI, -4.57% to 4.67%]). In the EEG-guided group compared with the usual care group, the median volatile anesthetic minimum alveolar concentration was 0.14 (95% CI, 0.15 to 0.13) lower (0.66 vs 0.80) and there was a 7.7-minute (95% CI, 10.6 to 4.7) decrease in the median total time spent with EEG suppression (4.0 vs 11.7 min). There were no significant differences between groups in median length of intensive care unit (difference, 0 days [95% CI, -0.31 to 0.31]) or hospital stay (difference, 0 days [95% CI, -0.94 to 0.94]). No patients reported intraoperative awareness. Medical complications occurred in 64 of 567 patients (11.3%) in the EEG-guided group and 73 of 573 (12.7%) in the usual care group. Thirty-day mortality occurred in 8 of 567 patients (1.4%) in the EEG-guided group and 13 of 573 (2.3%) in the usual care group.

Conclusions and Relevance

Among older adults undergoing cardiac surgery, EEG-guided anesthetic administration to minimize EEG suppression, compared with usual care, did not decrease the incidence of postoperative delirium. This finding does not support EEG-guided anesthesia for this indication.

Trial Registration

ClinicalTrials.gov Identifier: NCT02692300.

Association between postoperative hyperactive delirium and major complications in elderly patients undergoing emergency hip fracture surgery: A large-scale cohort study

AIM

This cohort study aimed to explore the connection between postoperative hyperactive delirium and major complications in elderly patients undergoing emergency hip fracture surgery.

METHODS

Elderly patients aged 65 years and older undergoing emergency hip fracture surgery were included in the study. The presence of postoperative hyperactive delirium was assessed, and logistic regression analysis, following propensity score matching, was conducted to investigate the association between postoperative hyperactive delirium and major complications occurring 30 and 90 days post-surgery. The analysis controlled for potential confounding factors.

RESULTS

After propensity score matching, the analysis included 13 590 patients, equally distributed with 6795 in each group. The group experiencing postoperative hyperactive delirium exhibited a significantly elevated risk of 30-day postoperative complications, including acute renal failure, pneumonia, septicemia, and stroke, with adjusted odds ratios ranging from 1.64 to 2.39. Furthermore, this group displayed notably higher rates of 90-day postoperative complications, encompassing mortality, acute renal failure, pneumonia, septicemia, and stroke, with a significantly increased incidence of mortality within 90 days.

CONCLUSION

Postoperative hyperactive delirium in elderly patients undergoing emergency hip fracture surgery is significantly linked to an increased risk of major complications at both 30 and 90 days post-surgery. These findings underscore the critical importance of delirium prevention and management in this patient population, offering the potential to reduce the occurrence of postoperative complications. Geriatr Gerontol Int 2024; 24: 730-736.

A novel nomogram for the prediction of subsyndromal delirium in patients in intensive care units: A prospective, nested case-controlled study

BACKGROUND

Subsyndromal delirium is a dynamic, recognizable condition commonly observed in intensive care unit (ICU) patients that can lead to poor patient prognosis, and its prompt recognition and management can prevent disease progression. However, no evidence-based predictive tool has been developed specifically to assess the occurrence of subsyndromal delirium in the ICU.

OBJECTIVE

To develop and validate a novel, simple and effective tool for estimating the risk of subsyndromal delirium among ICU patients.

DESIGN

A prospective, nested case-controlled study.

DATA SOURCES

A total of 731 patients were recruited from the central ICU of a tertiary hospital in southwestern China from August 2021 to November 2022.

METHODS

The least absolute shrinkage and selection operator was applied to screen potential features for univariate and multivariate logistic regression. A nomogram was constructed using the selected variables. The performance of the nomogram was evaluated by combining the area under the receiver operating characteristic curve (AUC), calibration curves and decision curve analysis (DCA).

RESULTS

The prevalence of subsyndromal delirium among ICU patients was 23.06 %. Multiple logistic regression analysis revealed that the independent predictive factors for subsyndromal delirium among ICU patients were vision impairment, a history of falls, the use of restraint, blood transfusion, the use of antibiotics, surgery, the Caprini score, and the Braden score, all of which were used to construct the nomogram. The AUCs for the model were 0.710 (95 % CI, 0.654-0.766, P < 0.001) and 0.825 (95 % CI, 0.732-0.917, P < 0.001) in the training and validation cohorts, respectively, indicating that the model had high accuracy in distinguishing patients with and without subsyndromal delirium. The calibration curve of the nomogram showed good consistency between the predicted and actual probabilities. The DCA indicated that the nomogram has clinical application for patients in the ICU.

CONCLUSIONS

We developed an easy-to-use nomogram for identifying subsyndromal delirium in ICU patients with satisfactory predictive ability based on simple and easily accessible clinical features. The nomogram can identify ICU patients at high-risk for subsyndromal delirium and may be a useful subsyndromal delirium tool for current ICU physicians.

Prevalence and risk factors of subsyndromal delirium among postoperative patients: A systematic review and meta-analysis

AIM

The aim of this study is to determine the prevalence and risk factors for subsyndromal delirium in the postoperative patient.

DESIGN

A systematic review and meta-analysis.

METHODS

The Review Manager 5.3 statistics platform and the Newcastle-Ottawa Scale were used for quality evaluation.

DATA SOURCES

The following databases were searched: PubMed, Web of Science, EMBASE, The Cochrane Library, Scopus and EBSCO from January 2000 to December 2021. Additional sources were found by looking at relevant articles' citations.

RESULTS

A total of 1744 titles were originally identified, and five studies including 962 patients were included in the systematic review, with a pooled prevalence of postoperative subsyndromal delirium (PSSD) of 30% (95% CI: 0.28-0.32). Significant risk variables for PSSD were older age, low levels of education (≤9 years), cognitive impairment, higher comorbidity score, and the duration of operation.

CONCLUSION

PSSD is prevalent and is associated with a variety of risk factors as well as low academic performance.

IMPACT

Identification and clinical management of patients with PSSD should be improved. Future research on PSSD risk factors should look at a wider range of intraoperative and postoperative risk factors that can be changed.

PATIENT AND PUBLIC CONTRIBUTION

No Patient or Public Contribution.

Identification of risk factors for the onset of delirium associated with COVID-19 by mining nursing records

COVID-19 has a range of complications, from no symptoms to severe pneumonia. It can also affect multiple organs including the nervous system. COVID-19 affects the brain, leading to neurological symptoms such as delirium. Delirium, a sudden change in consciousness, can increase the risk of death and prolong the hospital stay. However, research on delirium prediction in patients with COVID-19 is insufficient. This study aimed to identify new risk factors that could predict the onset of delirium in patients with COVID-19 using machine learning (ML) applied to nursing records. This retrospective cohort study used natural language processing and ML to develop a model for classifying the nursing records of patients with delirium. We extracted the features of each word from the model and grouped similar words. To evaluate the usefulness of word groups in predicting the occurrence of delirium in patients with COVID-19, we analyzed the temporal changes in the frequency of occurrence of these word groups before and after the onset of delirium. Moreover, the sensitivity, specificity, and odds ratios were calculated. We identified (1) elimination-related behaviors and conditions and (2) abnormal patient behavior and conditions as risk factors for delirium. Group 1 had the highest sensitivity (0.603), whereas group 2 had the highest specificity and odds ratio (0.938 and 6.903, respectively). These results suggest that these parameters may be useful in predicting delirium in these patients. The risk factors for COVID-19-associated delirium identified in this study were more specific but less sensitive than the ICDSC (Intensive Care Delirium Screening Checklist) and CAM-ICU (Confusion Assessment Method for the Intensive Care Unit). However, they are superior to the ICDSC and CAM-ICU because they can predict delirium without medical staff and at no cost.

Dynamic Nomogram for Subsyndromal Delirium in Adult Intensive Care Unit: A Prospective Cohort Study

Purpose

To develop a dynamic nomogram of subsyndromal delirium (SSD) in intensive care unit (ICU) patients and internally validate its efficacy in predicting SSD.

Patients and Methods

Patients who met the inclusion and exclusion criteria in the ICU of a tertiary hospital in Zhejiang from September 2021 to June 2022 were selected as the research objects. The patient data were randomly divided into the training set and validation set according to the ratio of 7:3. The least absolute shrinkage and selection operator (LASSO) and multivariate logistic regression were used to screen the predictors of SSD, and R software was used to construct a dynamic nomogram. Receiver operating characteristic (ROC) curve, calibration band and decision curve were used to evaluate the discrimination, calibration and clinical effectiveness of the model.

Results

A total of 1000 eligible patients were included, including 700 in the training set and 300 in the validation set. Age, drinking history, C reactive protein level, APACHE II, indwelling urinary catheter, mechanical ventilation, cerebrovascular disease, respiratory failure, constraint, dexmedetomidine, and propofol were predictors of SSD in ICU patients. The ROC curve values of the training set was 0.902 (95% confidence interval: 0.879-0.925), the best cutoff value was 0.264, the specificity was 78.4%, and the sensitivity was 88.0%. The ROC curve values of the validation set was 0.888 (95% confidence interval: 0.850-0.930), the best cutoff value was 0.543, the specificity was 94.9%, and the sensitivity was 70.9%. The calibration band showed good calibration in the training and validation set. Decision curve analysis showed that the net benefit in the model was significantly high.

Conclusion

The dynamic nomogram has good predictive performance, so it is a precise and effective tool for medical staff to predict and manage SSD in the early stage.

The risk factors for and the frequency and outcomes of subsyndromal delirium among patients who have undergone cardiac surgery: a protocol for systematic review and meta-analysis

INTRODUCTION

Several key symptoms must be present for the accurate diagnosis of patients with postoperative cardiac delirium. Some patients present with symptoms of delirium but do not meet the diagnostic criteria for delirium; such individuals are considered to have having subsyndromal delirium (SSD). SSD is associated with misdiagnosis and poor outcomes. However, to date, no systematic review (SR) has examined the frequency of, risk factors for, and outcomes of SSD among adults who have undergone cardiac surgery.

METHODS AND ANALYSIS

The aim of this SR is to identify those studies that have explored SSD after cardiac surgery. MeSH and free entry terms associated with "subsyndromal delirium" and "subclinical delirium" will be used to search for relevant studies. The PubMed, Web of Science, OVID, Cochrane Library, CINAHL, EMBASE, PsycINFO, China National Knowledge Infrastructure, Wanfang data, VIP database and SinoMed will be searched from inception to the date of retrieval without any restrictions. The primary outcomes will be the frequency of SSD, the risk factors for SSD, and the outcomes of SSD. Analyses will be performed using STATA V.16.0, and descriptive analyses will be performed if the data are not suitable for meta-analysis (ie, data with significant heterogeneity or from different comparisons).

ETHICS AND DISSEMINATION

The SR will examine the frequency of, risk factors for and outcomes of SSD in adults who have undergone cardiac surgery. The results will provide guidance for the identification of knowledge gaps in this field, and areas for further research will be highlighted. The review protocol will be submitted for publication in peer-reviewed journals for dissemination of the findings. Individual patient data will not be included in this protocol, so ethical approval will not be needed.

PROSPERO REGISTRATION NUMBER

CRD42022379211.

Early incident and subsyndromal delirium in older patients undergoing elective surgical procedures: a randomized clinical trial of an avoid delirium protocol

Background

Pharmacological avoidance guidelines for preventing delirium have been suggested; however, there are limited pragmatic studies of these strategies. Early (<24 h) delirium can be observed in the postoperative care unit and is associated with an increased risk of subsequent delirium. We examined the effectiveness of an avoid delirium protocol (ADP) in older (>65 years) patients undergoing elective surgeries.

Methods

The randomized controlled trial assessed an ADP developed using the American Geriatric Society's Clinical Practice Guidelines for Postoperative Delirium in Older Adults, on early (<24 h) incident or subsyndromal delirium. Delirium was assessed using the confusion assessment method before surgery, in the post-anesthesia care unit, and on postoperative day 1. The primary outcome of early delirium was the combined incidence of incident or subsyndromal delirium.

Results

Early delirium was identified in 24/235 patients (10.2%) with a risk ratio of 1.27 (95% CI 0.59-2.73, P = 0.667) for patients randomized to the ADP. In cases with protocol adherence and no benzodiazepine use, early delirium was present in 10/ 73 (13.7%) compared to 14/148 (9.5%) in non-adherent cases [risk ratio 1.45 (95% CI 0.57-3.10, P = 0.362)]. Lower American Society of Anesthesiologists physical class [odds ratio 3.31 (95% CI 1.35-8.92, P = 0.008)] and an inpatient admission [odds ratio 2.67 (95% CI 1.55-4.87, P = 0.0002)] were associated with early delirium.

Conclusions

Our findings suggest that pharmacological avoidance protocols limiting or avoiding the use of specific classes of medications are not effective in reducing early incident or subsyndromal delirium in older patients undergoing elective surgery.

Factors associated with maintaining walking ability postoperation for hip fractures and the predictive value of the CGA7 score for postoperative walking ability

AIM

Patients with hip fractures have a high rate of mortality or decreased mobility, despite early operative treatment and rehabilitation. The first aim of this study was to investigate the factors of decreased walking ability after hip fracture based on whether walking ability was or was not maintained postoperatively. The second aim was to examine the usefulness of the Comprehensive Geriatric Assessment 7 (CGA7), modified from the conventional Comprehensive Geriatric Assessment, for predicting postoperative walking ability.

METHODS

This study included patients who were treated surgically for hip fractures. We divided patients by whether they did or did not maintain their walking ability postoperatively. We registered the following demographic data: walking ability preadmission and at discharge, CGA7 score, cognitive impairment, the patient's prefracture status, fracture type, surgical waiting time, hospital stay duration, limitation of weight-bearing, postoperative complications, transfer to rehabilitation hospital, final living place, and follow-up period. The characteristics of the two groups were compared using Wilcoxon's rank-sum test, the chi-squared test, or Fisher's exact test.

RESULTS

Among 855 patients, 616 (73.0%) patients maintained walking ability and 239 (27.0%) patients did not. Multivariate logistic regression revealed that the factors of age, sex, preoperative walking ability, and postoperative complications were significantly associated with maintaining postoperative walking ability. Furthermore, the higher the CGA7 score, the more likely were patients to maintain their walking ability (odds ratio, 0.72; 95% confidence interval, 0.61-0.85; P < 0.001).

CONCLUSIONS

Patients who had a low CGA7 score had the potential risk of decreased walking ability. Geriatr Gerontol Int 2023; 23: 830-835.

Grip Strength is a Predictor for Subsyndromal Delirium Among Older Adults Following Joint Replacement

Background

Delirium is common in older patients during the postoperative period, increasing the number of adverse events, and grip strength is associated with delirium. Subsyndromal delirium (SSD) is a prostate of clinical delirium; nevertheless, the relationship between grip strength and SSD has not been elucidated. This study aimed to examine the association between grip strength and SSD in the elderly after arthroplasty.

Methods

A total of 181 patients were recruited from two Chinese hospitals. SSD and delirium were evaluated before the surgery and the first week after surgery using the confusion assessment method. The Mini-mental State Examination was used to assess patients' cognitive function, and their grip strength was evaluated with an electronic hand dynamometer before surgery. Logistic regression and ROC curve analysis were conducted to determine the odds ratio and predictive value of grip strength for SSD.

Results

The incidence of SSD and postoperative delirium (POD) was 41.44% and 14.36% for the elderly following arthroplasty respectively, and approximately 1/3 of SSD progressed into POD. Older age, declined cognitive function, fall history, and lower grip strength were risk factors for SSD (P<0.05). The area under the ROC curve of grip strength was 0.863 and 0.900 for males and females respectively, and the cut-off point of it was determined to be 22.050 kg for men and 18.050 kg for women.

Conclusion

SSD and POD are common among older people. Decreased grip strength, advanced age, lower cognitive function, and fall history were independent risk factors for SSD, and grip strength was a significant predictor for SSD in aged patients after the arthroplasty.

Neurological complications in patients undergoing general surgery: A literature review

Surgical procedures are extremely burdensome for patients, as in addition to complications directly related to the intervention, they expose the patient to further complications resulting from the disturbance of key functions of homeostasis in the body's systems, particularly the circulatory, respiratory, and nervous systems. Furthermore, they may contribute to the exacerbation of symptoms of underlying chronic diseases. This paper focuses on the most common possible neurological complications that may occur after surgical procedures and includes topics such as stroke, chronic pain, neuropathy, and delirium. The risk factors for neurological deficits, their known or possible etiology, the most characteristic symptoms, and potential preventive actions are discussed. The paper analyzes articles from the PubMed, ResearchGate, and Scopus databases. A surge0on's knowledge of possible complications that may occur in the perioperative period enables early recognition and effective reduction of their negative impact on the patient's functioning and quality of life after surgery, contributing to better overall treatment outcomes.

Ramelteon for delirium prevention in hospitalized patients: An updated meta-analysis and trial sequential analysis of randomized controlled trials

Although ramelteon has been examined as a relatively new therapeutic option for delirium prevention, current evidence to evaluate its efficacy is limited. We conducted an updated meta-analysis and examine the reliability of existing evidence regarding the effect of ramelteon on delirium prevention in hospitalized patients. Seven major electronic databases were systematically searched to identify randomized controlled trials examining the efficacy of ramelteon in delirium prevention. Data were pooled using a frequentist-restricted maximum-likelihood random-effects model. A trial sequential analysis was performed using relative risk reduction thresholds of 50%. The primary outcome was the incidence of delirium (reported as odds ratio with 95% confidence intervals). The secondary outcomes were the days of delirium, all-cause mortality, and all-cause discontinuation. Of 187 potentially eligible studies identified, 8 placebo-controlled randomized controlled trials (n = 587) were included. This updated meta-analysis showed that ramelteon was associated with lower odds of delirium occurrence than placebo (0.50; 0.29-0.86; I²  = 17.48%). In trial sequential analysis, the effect of ramelteon across the superiority boundary when using a relative risk reduction threshold ranging from 40% to 60%. In subgroup analyses, ramelteon compared with placebo was associated with lower odds of delirium occurrence in the elderly group (k = 5; 0.28; 0.09-0.85; I²  = 27.93%) and multiple dosage group (k = 5; 0.34; 0.14-0.82; I²  = 44.24%) but not in the non-elderly and non-multiple dosage groups. When considering surgical patients and medical patients separately, ramelteon showed a trend in the treatment of delirium prevention in both groups, while these findings were not statistically significant. No significant between-group differences were found in the secondary outcomes. The current meta-analysis provides updated and reliable evidence that ramelteon, in comparison with placebo, reduces the risk of delirium among hospitalized patients.

Recent advances and perspectives of postoperative neurological disorders in the elderly surgical patients

Postoperative neurological disorders, including postoperative delirium (POD), postoperative cognitive dysfunction (POCD), postoperative covert ischemic stroke, and hemorrhagic stroke, are challenging clinical problems in the emerging aged surgical population. These disorders can deteriorate functional outcomes and long‐term quality of life after surgery, resulting in a substantial social and financial burden to the family and society. Understanding predisposing and precipitating factors may promote individualized preventive treatment for each disorder, as several risk factors are modifiable. Besides prevention, timely identification and treatment of etiologies and symptoms can contribute to better recovery from postoperative neurological disorders and lower risk of long‐term cognitive impairment, disability, and even death. Herein, we summarize the diagnosis, risk factors, prevention, and treatment of these postoperative complications, with emphasis on recent advances and perspectives.