Risk factors of postoperative delirium after cardiac surgery: a meta-analysis

Predictive factors for postoperative delirium in thoracic surgery

OBJECTIVE

We examined cases in which delirium developed after thoracic surgery under general anesthesia at our hospital to determine the predictive factors for postoperative delirium, as well as the perioperative findings in cases showing postoperative delirium.

METHODS

This retrospective study included 1674 patients who underwent surgery under general anesthesia at our hospital between 2012 and 2022, A psychiatrist diagnosed postoperative delirium using the Confusion Assessment Method.

RESULTS

There were 99 (5.9%) patients with postoperative delirium in our study, including 85 (86%) men, of whom 31 (31%) had a history of cerebrovascular disease. The incidence of postoperative delirium in patients aged > 80 years was 20% (36/182). The postoperative delirium group showed significantly longer hospital stays and more frequent postoperative complications than the group without postoperative delirium. In univariate analysis, age ≥ 80 years, male sex, history of cerebrovascular disease, hypertension, history of atrial fibrillation, and history of smoking were identified as significant factors, while multivariate analysis identified age ≥ 80 years, male sex, history of cerebrovascular disease, hypertension, and history of smoking as significant factors (odds ratios = 5.15, 2.04, 3.10, 1.67, and 2.36, respectively). In the 169 cases with none of these five factors, the postoperative delirium risk was 0% (0/169).

CONCLUSIONS

In patients undergoing thoracic surgery, predictive factors for postoperative delirium include age ≥ 80 years, male sex, history of cerebrovascular disease, hypertension, and smoking history. The findings also indicate that patients with these risk factors may require psychiatric consultation before surgery.

Effect of mannitol on postoperative delirium in patients undergoing coronary artery bypass graft: a randomised controlled trial

OBJECTIVE

Postoperative delirium (POD), especially after cardiac surgery with cardiopulmonary bypass (CPB), is a relatively common and severe complication increasing side effects, length of hospital stay, mortality and healthcare resource costs. This study aimed to determine the impact of using mannitol serum in the prime of CPB for preventing the occurrence of delirium in patients undergoing coronary artery bypass surgery.

METHODS

This study is a single-centre, double-blinded, randomised, controlled trial that was conducted from December 2022 to May 2023. Patients in the age range of 18-70 who underwent elective coronary artery bypass surgery were included in the study. In the control group (n=45), the prime solution included Ringer's lactate serum. In the intervention group (n=45), the prime solution consisted of 200 mL mannitol serum and Ringer's lactate serum. The primary outcome of the study was the incidence of POD. Secondary outcomes included the duration of mechanical ventilation, length of stay in the intensive care unit (ICU) and 30-day in-hospital mortality.

RESULTS

There were no statistically significant differences in demographic characteristics and risk factors between the control and intervention groups (p<0.05). However, the incidence of POD was significantly lower in the intervention group compared with the control group (22.25% vs 42.2%, p=0.035). There were no significant differences between the two groups regarding CPB time, aortic cross-clamp time, duration of mechanical ventilation and length of stay in ICU (p<0.05). Additionally, mortality rates and rates of return to the operating room did not differ significantly between the two groups (p<0.05).

CONCLUSIONS

This study concluded that adding mannitol to the prime of CPB pump can help reduce the incidence of delirium after cardiac surgery.

TRIAL REGISTRATION NUMBER

IRCT20221129056660N1.

A nomogram for predicting postoperative delirium in pediatric patients following cardiopulmonary bypass: A prospective observational study

OBJECTIVES

To create a nomogram for early delirium detection in pediatric patients following cardiopulmonary bypass.

RESEARCH METHODOLOGY/DESIGN

This prospective, observational study was conducted in the Cardiac Intensive Care Unit at a Children's Hospital, enrolling 501 pediatric patients from February 2022 to January 2023. Perioperative data were systematically collected through the hospital information system. Postoperative delirium was assessed using the Cornell Assessment of Pediatric Delirium (CAPD). For model development, Least Absolute Shrinkage and Selection Operator (LASSO) regression was employed to identify the most relevant predictors. These selected predictors were then incorporated into a multivariable logistic regression model to construct the predictive nomogram. The performance of the model was evaluated by Harrell's concordance index, receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis. External validity of the model was confirmed through the C-index and calibration plots.

RESULTS

Five independent predictors were identified: age, SpO2 levels, lymphocyte count, diuretic use, and midazolam administration, integrated into a predictive nomogram. This nomogram demonstrated strong predictive capacity (AUC 0.816, concordance index 0.815) with good model fit (Hosmer-Lemeshow test p = 0.826) and high accuracy. Decision curve analysis showed a significant net benefit, and external validation confirmed the nomogram's reliability.

CONCLUSIONS

The study successfully developed a precise and effective nomogram for identifying pediatric patients at high risk of post-cardiopulmonary bypass delirium, incorporating age, SpO2 levels, lymphocyte counts, diuretic use, and midazolam medication.

IMPLICATIONS FOR CLINICAL PRACTICE

This nomogram aids early delirium detection and prevention in critically ill children, improving clinical decisions and treatment optimization. It enables precise monitoring and tailored medication strategies, significantly contributes to reducing the incidence of delirium, thereby enhancing the overall quality of patient care.

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.

Risk factors for postoperative delirium in patients with cardiac surgery

Purpose: Patients admitted to the intensive care unit (ICU) after cardiac surgery are at high risk of delirium due to a variety of factors. This study aimed to identify the incidence of postoperative delirium in adult patients with cardiac surgery and its risk factors, such as characteristics of subjects, disease and treatment-related, as well as nursing-related characteristics. Methods: The study was performed on adult patients who underwent cardiac surgery at Y University Hospital in D city; a total of 195 patients met the inclusion criteria. Results: The results of this study determined that 67 of 195 adult cardiac surgery patients had postoperative delirium, 53.7% of which occurred in the ICU and 46.3% in the general ward. Risk factors of postoperative delirium were postoperative symptoms of inflammation (odds ratio [OR] = 10.18, p = 0.002), continuous renal replacement therapy application after surgery (OR = 9.05, p = 0.006), postoperative sleep disorder (OR = 8.98, p < 0.001), age (OR = 6.23, p = 0.006), length of stay in the ICU (OR = 3.83, p = 0.031), history of stroke (OR = 3.71, p = 0.033), the number of postoperative catheter retention (OR = 1.53, p = 0.065), Acute Physiology and Chronic Health Evaluation Ⅱ score (OR = 1.12, p = 0.006), and time of operation (OR = 1.01, p = 0.042). Conclusion: This study confirmed that after cardiac surgery, postoperative delirium occurred in patients during their ICU stay and after their transfer to a general ward. Considering that after cardiac surgery ICU-related factors affect the incidence of delirium in the general ward, there is a need for continuous monitoring of ICU-related factors after the patient gets transferred to a general ward.

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.

Postoperative cognitive dysfunction: a concept analysis

BACKGROUND

Post-operative cognitive dysfunction (POCD) is a concern for clinicians that often presents post-surgery where generalized anesthesia has been used. Its prevalence ranges from 36.6% in young adults to 42.4% in older individuals. Conceptual clarity for POCD is lacking in the currently body literature. Our two-fold purpose of this concept analysis was to (1) critically appraise the various definitions, while also providing the best definition, of POCD and (2) narratively synthesize the attributes, surrogate or related terms, antecedents (risk factors), and consequences of the concept.

METHOD

The reporting of our review was guided by the PRISMA statement and the 6-step evolutionary approach to concept analysis developed by Rodgers. Three databases, including Medline, CINAHL, and Web of Science, were searched to retrieve relevant literature on the concept of POCD. Two independent reviewers conducted abstract and full-text screening, data extraction, and appraisal. The review process yielded a final set of 86 eligible articles.

RESULT

POCD was defined with varying severities ranging from subtle-to-extensive cognitive changes (1) affecting single or multiple cognitive domains that manifest following major surgery (2), is transient and reversible, and (3) may last for several weeks to years. The consequences of POCD may include impaired quality of life, resulting from withdrawal from the labor force, increased patients' dependencies, cognitive decline, an elevated risk of dementia, rising healthcare costs, and eventual mortality.

CONCLUSION

This review resulted in a refined definition and comprehensive analysis of POCD that can be useful to both researchers and clinicians. Future research is needed to refine the operational definitions of POCD so that they better represent the defining attributes of the concept.

Intraoperative use of processed electroencephalogram in a quaternary center: a quality improvement audit

Although intraoperative electroencephalography (EEG) is not consensual among anesthesiologists, growing evidence supports its use to titrate anesthetic drugs, assess the level of arousal/consciousness, and detect ischemic cerebrovascular events; in addition, intraoperative EEG monitoring may decrease the incidence of postoperative neurocognitive disorders. Based on the known and potential benefits of intraoperative EEG monitoring, an educational program dedicated to staff anesthesiologists, residents of Anesthesiology and anesthesia technicians was started at Cleveland Clinic Abu Dhabi in May 2022 and completed in June 2022, aiming to have all patients undergoing general anesthesia with adequate brain monitoring and following international initiatives promoting perioperative brain health. All the surgical cases performed under General Anesthesia at 24 daily locations were prospectively inspected during 15 consecutive working days in March 2023. The use or absence of a processed EEG monitor was registered. Of 379 surgical cases distributed by 24 locations under General Anesthesia, 233 cases (61%) had processed EEG monitoring. The specialty with the highest use of EEG monitoring was Cardiothoracic Surgery, with 100% of cases, followed by interventional Cardiology (90%) and Vascular Surgery (75%). Otorhinolaryngology (29%), Gastrointestinal Endoscopy (25%), and Interventional Pulmonology (20%) were the areas with the lowest use of EEG monitoring. Of note, in the Neuroradiology suite, no processed EEG monitor was used in cases under General Anesthesia. We identified a reasonable use of EEG monitoring during general anesthesia, unfortunately not reaching our target of 100%. The educational and support program previously implemented within the Anesthesiology Institute needs to be continued and improved, including workshops, online discussions, and journal club sessions, to increase the use of EEG monitoring in underused areas.

The Influence of Preoperative Physical Activity on Intraoperative Brain Function in Cardiac Surgical patients

Background Preoperative physical activity and intraoperative brain health are recognized to influence postoperative delirium (POD). Electroencephalogram (EEG) burst suppression and cerebral desaturation are indicators of abnormal intraoperative brain health. Our study aimed to investigate the associations between preoperative physical activity and intraoperative EEG burst suppression and cerebral desaturation. Methods We retrospectively analyzed data from 67 patients from one of the institutions participating in a multisite randomized controlled trial, PANDORA, involving patients undergoing cardiac surgery. The preoperative PCS12 score calculated using the SF12 questionnaire was used as an indicator of preoperative physical activity. Intraoperative EEG and cerebral oximetry data (not the current standard of care in this facility) were collected, and the anesthesiologists were blinded to the information. We analyzed the following associations between the PCS12 score and i) burst suppression duration, ii) the number of cerebral desaturations, and iii) the number of observations with concurrent cerebral desaturation and burst suppression using a generalized linear model. The results are presented as percentage changes in outcomes, and a 95% C.I. p value < 0.05 was considered to indicate statistical significance. Results Each unit increase in the PCS12 score was associated with a 3.3% decrease in the duration of burst suppression (-3.3 [-5.3, -1.2], p value = 0.002). The duration of burst suppression decreased by 29.2% with each successive quartile increase in the PCS-12 score, indicating a dose‒response relationship (-29.2 [-41.6, -16], p < 0.001). Specifically, the patients in the last three quartiles exhibited a 55.4% reduction in BSD compared to those in the first quartile (-55.4 [-74.4, -24.6], p = 0.002) (Fig. 2). We did not observe any significant association between the PCS12 score and cerebral desaturation. Conclusion Decreased preoperative physical activity, as measured by the SF-12 questionnaire, is significantly associated with increased EEG burst suppression duration. Preoperative physical activity did not show any association with cerebral desaturations and concurrent cerebral desaturation and burst suppression. Clinical Trial information ClinicalTrials.gov Identifier- NCT04093219 https://clinicaltrials.gov/ct2/show/NCT04093219 Principal Investigator - Balachundhar Subramaniam Date of registration - September 13, 2019.

Opioid-free anaesthesia with dexmedetomidine and lidocaine versus remifentanil-based anaesthesia in cardiac surgery: study protocol of a French randomised, multicentre and single-blinded OFACS trial

INTRODUCTION

Intraoperative opioids have been used for decades to reduce negative responses to nociception. However, opioids may have several, and sometimes serious, adverse effects. Cardiac surgery exposes patients to a high risk of postoperative complications, some of which are common to those caused by opioids: acute respiratory failure, postoperative cognitive dysfunction, postoperative ileus (POI) or death. An opioid-free anaesthesia (OFA) strategy, based on the use of dexmedetomidine and lidocaine, may limit these adverse effects, but no randomised trials on this issue have been published in cardiac surgery.We hypothesised that OFA versus opioid-based anaesthesia (OBA) may reduce the incidence of major opioid-related complications after cardiac surgery.

METHODS AND ANALYSIS

Multicentre, randomised, parallel and single-blinded clinical trial in four cardiac surgical centres in France, including 268 patients scheduled for coronary artery bypass grafting under cardiac bypass, with or without aortic valve replacement. Patients will be randomised to either a control OBA protocol using remifentanil or an OFA protocol using dexmedetomidine/lidocaine. The primary composite endpoint is the occurrence of at least one of the following: (1) postoperative cognitive disorder evaluated by the Confusion Assessment Method for the Intensive Care Unit test, (2) POI, (3) acute respiratory distress or (4) death within the first 48 postoperative hours. Secondary endpoints are postoperative pain, morphine consumption, nausea-vomiting, shock, acute kidney injury, atrioventricular block, pneumonia and length of hospital stay.

ETHICS AND DISSEMINATION

This trial has been approved by an independent ethics committee (Comité de Protection des Personnes Ouest III-Angers on 23 February 2021). Results will be submitted in international journals for peer reviewing.

TRIAL REGISTRATION NUMBER

NCT04940689, EudraCT 2020-002126-90.

Effects of Intranasal Insulin Pretreatment on Preoperative Sleep Quality and Postoperative Delirium in Patients Undergoing Valve Replacement for Rheumatic Heart Disease

Background

Postoperative delirium (POD) is a common neurological complication associated with valve replacement. Preoperative sleep disturbance is a risk factor for POD development, and nasal insulin modulates the sleep-wake cycle. This study investigated the beneficial effects of intranasal insulin pretreatment on preoperative sleep quality and reducing POD in patients undergoing valve replacement for rheumatic heart disease.

Patients and Methods

This prospective, single-center, randomized controlled trial (RCT) included 76 adult patients aged 18-65 years undergoing valve surgery with cardiopulmonary bypass who were randomly allocated to receive intranasal insulin or normal saline interventions two days before surgery. POD incidence was on postoperative days 1 (T3), 2 (T4), and 3 (T5). Before the first intervention (T0), 1 d before surgery (T1), and before anesthesia on the day of surgery (T2), sleep quality was assessed and serum cortisol concentrations were measured. At T1 and T2, sleep quality related indicators monitored by sleep monitoring watches from the previous night were recorded.

Results

Compared with the normal saline group, 3 days after surgery, the insulin group showed a significantly reduced incidence of POD; significantly increased deep sleep, REM sleep, deep sleep continuity, and total sleep quality scores at T1 and T2; and significantly reduced serum cortisol concentration, PSQI scale, light sleep ratio, and wakefulness at T1 and T2.

Conclusion

The administration of 20 U of intranasal insulin twice daily, from 2 days preoperatively until 10 minutes preanesthesia on the day of surgery, can improved preoperative sleep quality significantly and reduced POD incidence in patients with rheumatic heart disease undergoing valve replacement.

Clinical Trial Registration

This study was registered with the Chinese Clinical Trial Registry (www.chictr.org.cn, with the unique identifier ChiCTR2100048515; July 9, 2021).

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.

Serum Neurofilament Light and Postoperative Delirium in Cardiac Surgery: A Preplanned Secondary Analysis of a Prospective Observational Study

BACKGROUND

Impaired cognition is a major predisposing factor for postoperative delirium, but it is not systematically assessed. Anesthesia and surgery may cause postoperative delirium by affecting brain integrity. Neurofilament light in serum reflects axonal injury. Studies evaluating the perioperative course of neurofilament light in cardiac surgery have shown conflicting results. The authors hypothesized that postoperative serum neurofilament light values would be higher in delirious patients, and that baseline concentrations would be correlated with patients' cognitive status and would identify patients at risk of postoperative delirium.

METHODS

This preplanned secondary analysis included 220 patients undergoing elective cardiac surgery with cardiopulmonary bypass. A preoperative cognitive z score was calculated after a neuropsychological evaluation. Quantification of serum neurofilament light was performed by the Simoa (Quanterix, USA) technique before anesthesia, 2 h after surgery, on postoperative days 1, 2, and 5. Postoperative delirium was assessed using the Confusion Assessment Method for Intensive Care Unit, the Confusion Assessment Method, and a chart review.

RESULTS

A total of 65 of 220 (29.5%) patients developed postoperative delirium. Delirious patients were older (median [25th percentile, 75th percentile], 74 [64, 79] vs. 67 [59, 74] yr; P < 0.001) and had lower cognitive z scores (-0.52 ± 1.14 vs. 0.21 ± 0.84; P < 0.001). Postoperative neurofilament light concentrations increased in all patients up to day 5, but did not predict delirium when preoperative concentrations were considered. Baseline neurofilament light values were significantly higher in patients who experienced delirium. They were influenced by age, cognitive z score, renal function, and history of diabetes mellitus. Baselines values were significantly correlated with cognitive z scores (r, 0.49; P < 0.001) and were independently associated with delirium whenever the patient's cognitive status was not considered (hazard ratio, 3.34 [95% CI, 1.07 to 10.4]).

CONCLUSIONS

Cardiac surgery is associated with axonal injury, because neurofilament light concentrations increased postoperatively in all patients. However, only baseline neurofilament light values predicted postoperative delirium. Baseline concentrations were correlated with poorer cognitive scores, and they independently predicted postoperative delirium whenever patient's cognitive status was undetermined.

EDITOR’S PERSPECTIVE

Intraoperative Blood Pressure Management and Its Effects on Postoperative Delirium After Cardiac Surgery: A Single-Center Retrospective Cohort Study

OBJECTIVES

There is accumulating evidence that blood pressure management might be associated with end-organ dysfunction after cardiac surgery. This study aimed to investigate the impact of intraoperative hypotension (IOH) on adverse neurologic outcomes and mortality.

DESIGN

A single-center retrospective cohort study.

SETTING

The Heart and Diabetes Centre Bad Oeynhausen NRW, Ruhr-University Bochum.

PARTICIPANTS

This retrospective cohort study included 31,315 adult patients who underwent elective cardiac surgery at the authors' institution between January 2009 and December 2018.

INTERVENTIONS

All cardiac surgery procedures except assist device implantation, organ transplantation, and emergency surgery.

MEASUREMENTS AND MAIN RESULTS

Adverse neurologic outcomes were defined as postoperative delirium and stroke. IOH was defined as mean arterial pressure below 60 mmHg for >2 minutes. The frequency of IOH episodes and the cumulative IOH duration were recorded. The association between IOH and adverse neurologic outcomes was examined with unadjusted statistical analysis and multiple logistic regression analysis. Eight hundred forty-nine (2.9%) patients developed postoperative stroke, and 2,401 (7.7%) patients developed postoperative delirium. The frequency of IOH episodes was independently associated with postoperative delirium in the multiple logistic regression analysis (odds ratio 1.02, 95% CI 1.003-1.03, p < 0.001), whereas there was no association between it and stroke.

CONCLUSION

This large retrospective monocentric cohort study revealed that increased episodes of IOH were associated with the risk of developing postoperative delirium after cardiac surgery. This might have important clinical implications with respect to careful and precise hemodynamic monitoring and proactive treatment, especially in patients with increased risk for postoperative delirium.

Triglyceride-glucose index predicts postoperative delirium in elderly patients with type 2 diabetes mellitus: a retrospective cohort study

BACKGROUND

Postoperative delirium (POD) is more prevalent among elderly patients with type 2 diabetes mellitus (T2DM). Insulin resistance (IR) can be assessed using the triglyceride-glucose (TyG) index, a novel biomarker. This study aims to investigate the predictive potential of the TyG index for POD in elderly patients with T2DM.

MATERIALS AND METHODS

Elderly patients (≥ 65) with T2DM who underwent non-neurosurgery and non-cardiac surgery were enrolled. Univariate and multivariate logistic regression analyses were conducted to assess the association between the TyG index and POD. Additionally, subgroup analyses were performed to compare the sex-specific differences in the predictive ability of the TyG index for POD.

RESULTS

A total of 4566 patients were included in this retrospective cohort. The receiver operating characteristic (ROC) curve analysis determined the optimal cut-off value for the TyG index to be 8.678. In the univariate model, a TyG index > 8.678 exhibited an odds ratio (OR) of 1.668 (95% CI: 1.210-2.324, P = 0.002) for predicting POD. In the multivariate regression models, the ORs were 1.590 (95% CI: 1.133-2.252, P < 0.008), 1.661 (95% CI: 1.199-2.325, P < 0.003), and 1.603 (95% CI: 1.137-2.283, P = 0.008) for different models. Subgroup analyses demonstrated that the predictive ability of the TyG index was more pronounced in females compared to males.

CONCLUSION

The TyG index shows promise as a novel biomarker for predicting the occurrence of POD in elderly surgical patients with T2DM.

Intraoperative EEG-based monitors: are we looking under the lamppost?

PURPOSE OF REVIEW

While electroencephalogram (EEG)-based depth of anesthesia monitors have been in use clinically for decades, there is still a major debate concerning their efficacy for detecting awareness under anesthesia (AUA). Further utilization of these monitors has also been discussed vividly, for example, reduction of postoperative delirium (POD).It seems that with regard to reducing AUA and POD, these monitors might be applicable, under specific anesthetic protocols. But in other settings, such monitoring might be less contributive and may have a 'built-it glass ceiling'.Recent advances in other venues of electrophysiological monitoring might have a strong theoretical rationale, and early supporting results, to offer a breakthrough out of this metaphorical glass ceiling. The purpose of this review is to present this possibility.

RECENT FINDINGS

Following previous findings, it might be concluded that for some anesthesia protocols, the prevailing depth of anesthesia monitors may prevent incidences of AUA and POD. However, in other settings, which may involve other anesthesia protocols, or specifically for POD - other perioperative causes, they may not. Attention-related processes measured by easy-to-use real-time electrophysiological markers are becoming feasible, also under anesthesia, and might be applicable for more comprehensive prevention of AUA, POD and possibly other perioperative complications.

SUMMARY

Attention-related monitoring might have a strong theoretical basis for the prevention of AUA, POD, and potentially other distressing postoperative outcomes, such as stroke and postoperative neurocognitive disorder. There seems to be already some initial supporting evidence in this regard.

Butyrylcholinesterase activity in patients with postoperative delirium after cardiothoracic surgery or percutaneous valve replacement- an observational interdisciplinary cohort study

BACKGROUND AND OBJECTIVES

Postoperative delirium is a frequent and severe complication after cardiac surgery. Activity of butyrylcholinesterase (BChE) has been discussed controversially regarding a possible role in its development. This study aimed to investigate the relevance of BChE activity as a biomarker for postoperative delirium after cardiac surgery or percutaneous valve replacement.

METHODS

A total of 237 patients who received elective cardiothoracic surgery or percutaneous valve replacement at a tertiary care centre were admitted preoperatively. These patients were tested with the Montreal Cognitive Assessment investigating cognitive deficits, and assessed for postoperative delirium twice daily for three days via the 3D-CAM or the CAM-ICU, depending on their level of consciousness. BChE activity was measured at three defined time points before and after surgery.

RESULTS

Postoperative delirium occurred in 39.7% of patients (n = 94). Univariate analysis showed an association of pre- and postoperative BChE activity with its occurrence (p = 0.037, p = 0.001). There was no association of postoperative delirium and the decline in BChE activity (pre- to postoperative, p = 0.327). Multivariable analysis including either preoperative or postoperative BChE activity as well as age, MoCA, type 2 diabetes mellitus, coronary heart disease, type of surgery and intraoperative administration of red-cell concentrates was performed. Neither preoperative nor postoperative BChE activity was independently associated with the occurrence of postoperative delirium (p = 0.086, p = 0.484). Preoperative BChE activity was lower in older patients (B = -12.38 (95% CI: -21.94 to -2.83), p = 0.011), and in those with a history of stroke (B = -516.173 (95% CI: -893.927 to -138.420), p = 0.008) or alcohol abuse (B = -451.47 (95% CI: -868.38 to -34.55), p = 0.034). Lower postoperative BChE activity was independently associated with longer procedures (B = -461.90 (95% CI: -166.34 to -757.46), p = 0.002), use of cardiopulmonary bypass (B = -262.04 (95% CI: -485.68 to -38.39), p = 0.022), the number of administered red cell-concentrates (B = -40.99 (95% CI: -67.86 to -14.12), p = 0.003) and older age (B = -9.35 (95% CI: -16.04 to -2.66), p = 0.006).

CONCLUSION

BChE activity is not independently associated with the occurrence of postoperative delirium. Preoperative BChE values are related to patients' morbidity and vulnerability, while postoperative activities reflect the severity, length and complications of surgery.

A novel risk assessment tool for postoperative delirium in vascular surgery: The stress model (Siena posTopeRative dElirium in vaScular Surgery)

OBJECTIVE

Postoperative delirium (POD) is a common complication with a high health-related impact. The creation of a model (Siena posTopeRative dElirium in vaScular Surgery) to identify high-risk patients with consecutive prompt diagnosis and correct management.

METHODS

This is an observational retrospective study to evaluate POD incidence in patients who underwent elective vascular surgery procedures between 2018 and 2020. POD was detected using CAM and defined as the onset of an acute confusional state, clinically manifesting as a disturbed state of consciousness, cognitive dysfunction, or alteration in perception and behavior. The total population was divided in the development and validation subsamples. Multivariable logistic regression analysis was performed, identifying variables related to the occurrence of POD. An additive score was created and the STRESS score was internally validated using the Validation subgroup.

RESULTS

A total of 1067 patients were enrolled. POD occurred in 111 cases (10.4%). Multivariable logistic regression analysis for POD occurrence revealed as significant predictors: age>75 years, CKD, dyslipidaemia, psychiatric disease, CAD, hospitalization in the previous month, preoperative NLR >3.59, preoperative Hb < 12 g/dl, preoperative Barthel score <75, major amputation, CLTI revascularization, general anesthesia, and postoperative urinary catheter. These variables were used to create the STRESS score. The model was applied to both development and validation subgroups; AUC was respectively 0.7079 (p < .0001) and 0.7270 (p < .0001).

CONCLUSION

The STRESS score has a good predictive potentiality for POD occurrence in elective vascular surgery procedures. However, implementation and external validation are needed to be correctly used in everyday clinical practice.

Risk factors for postoperative delirium in elderly patients undergoing heart valve surgery with cardiopulmonary bypass

BACKGROUND

The aim of this study was to identify the risk factors for postoperative delirium (POD) in elderly patients undergoing heart valve surgery with cardiopulmonary bypass (CPB).

METHODS

Elderly patients undergoing elective heart valve surgery with CPB in The First Affiliated Hospital of Wenzhou Medical University between March 2022 and March 2023 were selected for this investigation. They were divided into a POD group and a non-POD group. Their baseline information was collected and recorded, and the patients were subjected to neurocognitive function assessment using the Mini-Mental State Examination and the Montreal Cognitive Assessment scales before surgery. We also recorded their intraoperative indicators such as duration of surgery, duration of CPB, duration of aortic cross-clamp, blood transfusion, and postoperative indicators such as duration of mechanical ventilation, postoperative 24-hour drainage volume, and pain score. Regional cerebral oxygen saturation was monitored intraoperatively by near-infrared spectroscopy based INVOS5100C Regional Oximeter. Patients were assessed for the occurrence of POD using Confusion Assessment Method for the Intensive Care Unit, and logistic regression analysis of risk factors for POD was performed.

RESULTS

The study finally included 132 patients, with 47 patients in the POD group and 85 ones in the non-POD group. There were no significant differences in baseline information and preoperative indicators between the two groups. However, marked differences were identified in duration of surgery, duration of CPB, duration of aortic cross-clamp, duration of postoperative mechanical ventilation, postoperative length of stay in cardiac intensive care unit, postoperative length of hospital stay, intraoperative blood transfusion, postoperative pain score, and postoperative 24-hour drainage volume between the two groups (p < 0.05). Additionally, the two groups had significant differences in rScO2 at each intraoperative time point and in the difference of rScO2 from baseline at each intraoperative time point (p < 0.05). Multivariate logistic regression analysis showed that duration of surgery > 285 min (OR, 1.021 [95% CI, 1.008-1.035]; p = 0.002), duration of postoperative mechanical ventilation > 23.5 h (OR, 6.210 [95% CI, 1.619-23.815]; p = 0.008), and postoperative CCU stay > 3.5 d (OR, 3.927 [95% CI, 1.046-14.735]; p = 0.043) were independent risk factors of the occurrence of POD while change of rScO2 at T1>50.5 (OR, 0.832 [95% CI 0.736-0.941]; p = 0.003) was a protective factor for POD.

CONCLUSION

Duration of surgery duration of postoperative mechanical ventilation and postoperative CCU stay are risk factors for POD while change of rScO2 at T1 is a protective factor for POD in elderly patients undergoing heart valve surgery with CPB.

Postoperative delirium prediction after cardiac surgery using machine learning models

OBJECTIVE

Postoperative delirium (POD) is a common postoperative complication in elderly patients, especially those undergoing cardiac surgery, which seriously affects the short- and long-term prognosis of patients. Early identification of risk factors for the development of POD can help improve the perioperative management of surgical patients. In the present study, five machine learning models were developed to predict patients at high risk of delirium after cardiac surgery and their performance was compared.

METHODS

A total of 367 patients who underwent cardiac surgery were retrospectively included in this study. Using single-factor analysis, 21 risk factors for POD were selected for inclusion in machine learning. The dataset was divided using 10-fold cross-validation for model training and testing. Five machine learning models (random forest (RF), support vector machine (SVM), radial based kernel neural network (RBFNN), K-nearest neighbour (KNN), and Kernel ridge regression (KRR)) were compared using area under the receiver operating characteristic curve (AUC-ROC), accuracy (ACC), sensitivity (SN), specificity (SPE), and Matthews coefficient (MCC).

RESULTS

Among 367 patients, 105 patients developed POD, the incidence of delirium was 28.6 %. Among the five ML models, RF had the best performance in ACC (87.99 %), SN (69.27 %), SPE (95.38 %), MCC (70.00 %) and AUC (0.9202), which was far superior to the other four models.

CONCLUSION

Delirium is common in patients after cardiac surgery. This analysis confirms the importance of the computational ML models in predicting the occurrence of delirium after cardiac surgery, especially the outstanding performance of the RF model, which has practical clinical applications for early identification of patients at risk of developing POD.

Association Between Antidiabetic Drugs and Delirium: A Study Based on the Adverse Drug Event Reporting Database in Japan

BACKGROUND AND OBJECTIVE

Several associations between diabetes mellitus and delirium have been reported; however, they have been inconsistent, and evidence on the effects of antidiabetic medications on delirium is also limited. This study aimed to investigate whether the use of antidiabetic drugs is a risk factor for delirium development.

METHODS

Using the Japanese Adverse Event Reporting Database, we analyzed 662,899 reports between 2004 and 2022. Reporting odds ratios (RORs) and 95% confidence intervals (CIs) for delirium associated with diabetes and using each antidiabetic medication were calculated after adjusting for potential confounders.

RESULTS

Overall, 8892 of the reports analyzed were associated with delirium. A comparison of the incidence of delirium between patients with and without diabetes showed no significant difference, with 1.34% in patients without diabetes and 1.37% in those with diabetes. In each antidiabetic medication, signals for delirium were detected for sulfonylurea (crude ROR, 1.35; 95% CI 1.21-1.51) and insulin (crude ROR, 1.28; 95% CI 1.13-1.44). These results were maintained even after adjusting for factors with potential confounders (sulfonylurea: adjusted ROR, 1.75; 95% CI 1.54-2.00, insulin: adjusted ROR, 1.35; 95% CI 1.20-1.54).

CONCLUSIONS

Our results suggest no association between diabetes and delirium; however, using sulfonylurea and insulin may be associated with delirium development. Nonetheless, these findings should be validated in future studies.

Post-cardiac Surgery Delirium: When the Details Matter!

How to cite this article: Suresh V, Magoon R. Post-cardiac Surgery Delirium: When the Details Matter! Indian J Crit Care Med 2024;28(2):185-187.

The efficacy of earplugs and eye masks for delirium severity and sleep quality in patients undergoing coronary artery bypass grafting in cardiac intensive care units: A single-blind, randomised controlled trial

BACKGROUND AND PURPOSE

Delirium is a neuropsychiatric syndrome with a wide range of possible causes and multiple complications in patients admitted to intensive care units. It is, therefore, necessary to seek appropriate and safe strategies to prevent and manage delirium. This study is intended to examine the efficacy of eye masks and earplugs for delirium severity and sleep quality in patients with coronary artery bypass grafting in a cardiac intensive care unit.

MATERIALS AND METHODS

This single-blind, randomised controlled trial was conducted on 114 patients who were consecutively enrolled and randomly assigned to either the experimental group or the control group. The experimental group received routine care plus eye masks and earplugs, and the control group received only routine care. The delirium severity and sleep quality were measured with the Neelon and Champagne confusion scale and the Verran and Snyder-Halpern sleep scale.

RESULTS

The mean delirium severity score differed significantly between the two groups on the second, third, and fourth postoperative days (p < 0.001). Although the trend of changes in the mean delirium severity score from the first postoperative day (before the intervention) to the second, third, and fourth postoperative days was downward in the two groups (trending towards higher delirium severity), the control group experienced greater changes than the experimental group. An intragroup analysis of delirium severity detected a statistically significant difference in both the experimental and control groups (p < 0.001). The sleep quality domains (sleep disturbance, sleep effectiveness, sleep supplementation) showed a statistically significant difference between the two groups across the three intervention days (p < 0.001).

CONCLUSION

The overnight use of eye masks and earplugs were found to have positive effects on sleep quality domains (sleep disturbance, sleep effectiveness, sleep supplementation) and delirium severity in coronary artery bypass grafting patients admitted to the cardiac intensive care unit for several days. It was also found that a significant interaction effect between the sleep disturbance subscale and delirium severity exists.

CLINICAL TRIAL REGISTRATION NUMBER

(https://en.irct.ir): IRCT20210523051370N2.

Serum proteomic analysis in esophagectomy patients with postoperative delirium: A case-control study

BACKGROUND

Postoperative delirium occurs in up to 80% of patients undergoing esophagectomy. We performed an exploratory proteomic analysis to identify protein pathways that may be associated with delirium post-esophagectomy.

OBJECTIVES

Identify proteins associated with delirium and delirium severity in a younger and higher-risk surgical population.

METHODS

We performed a case-control study using blood samples collected from patients enrolled in a negative, randomized, double-blind clinical trial. English speaking adults aged 18 years or older, undergoing esophagectomy, who had blood samples obtained were included. Cases were defined by a positive delirium screen after surgery while controls were patients with negative delirium assessments. Delirium was assessed using Richmond Agitation Sedation Scale and Confusion Assessment Method for the Intensive Care Unit, and delirium severity was assessed by Delirium Rating Scale-Revised-98. Blood samples were collected pre-operatively and on post-operative day 1, and discovery proteomic analysis was performed. Between-group differences in median abundance ratios were reported using Wilcoxon-Mann-Whitney Odds (WMWodds1) test.

RESULTS

52 (26 cases, 26 controls) patients were included in the study with a mean age of 64 (SD 9.6) years, 1.9% were females and 25% were African American. The median duration of delirium was 1 day (IQR: 1-2), and the median delirium/coma duration was 2.5 days (IQR: 2-4). Two proteins with greater relative abundance ratio in patients with delirium were: Coagulation factor IX (WMWodds: 1.89 95%CI: 1.0-4.2) and mannosyl-oligosaccharide 1,2-alpha-mannosidase (WMWodds: 2.4 95%CI: 1.03-9.9). Protein abundance ratios associated with mean delirium severity at postoperative day 1 were Complement C2 (Spearman rs = -0.31, 95%CI [-0.55, -0.02]) and Mannosyl-oligosaccharide 1,2-alpha-mannosidase (rs = 0.61, 95%CI = [0.29, 0.81]).

CONCLUSIONS

We identified changes in proteins associated with coagulation, inflammation, and protein handling; larger, follow-up studies are needed to confirm our hypothesis-generating findings.

Whole Blood Reactivity to Viral and Bacterial Pathogens after Non-Emergent Cardiac Surgery during the Acute and Convalescence Periods Demonstrates a Distinctive Profile of Cytokines Production Compared to the Preoperative Baseline in Cohort of 108 Patients, Suggesting Immunological Reprogramming during the 28 Days Traditionally Recognized as the Post-Surgical Recovery Period

The release of danger signals from tissues in response to trauma during cardiac surgery creates conditions to reprogram the immune system to subsequent challenges posed by pathogens in the postoperative period. To demonstrate this, we tested immunoreactivity before surgery as the baseline (tbaseline), followed by subsequent challenges during the acute phase (t24h), convalescence (t7d), and long-term recovery (t3m). For 108 patients undergoing elective heart surgery, whole blood was stimulated with lipopolysaccharide (LPS), Influenza A virus subtype N2 (H3N2), or the Flublok™ vaccine to represent common pathogenic challenges. Leukocytosis, platelet count, and serum C-reactive protein (CRP) were used to measure non-specific inflammation. Cytokines were measured after 18 h of stimulation to reflect activation of the various cell types (activated neutrophils-IL-8; activated T cells-IL-2, IFNγ, activated monocyte (MO)-TNFα, IL-6, and deactivated or atypically activated MO and/or T cells-M-CSF, IL-10). IL-2 and IL-10 were increased at t7d, while TNFα was suppressed at t24h when LPS was utilized. Interestingly, M-CSF and IL-6 production was elevated at seven days in response to all stimuli compared to baseline. While some non-specific markers of inflammation (white cell count, IL-6, and IL-8) returned to presurgical levels at t3m, CRP and platelet counts remained elevated. We showed that surgical stimulus reprograms leukocyte response to LPS with only partial restoration of non-specific markers of inflammation.

Functional intervention following cardiac surgery to prevent postoperative delirium in older patients (FEEL WELL study)

BACKGROUND

Postoperative delirium is a common complication in patients after cardiac surgery, especially in older patients, and can manifest as a disturbance of attention and consciousness. It can lead to increased postoperative morbidity, prolonged need for care, and mortality. The presented study investigates whether the occurrence of postoperative delirium after cardiac surgery can be prevented by a multisensory stimulation. It was conducted as a prospective, randomized, controlled, non-pharmacological intervention study in the years 2021 and 2022 at the University Hospital Bonn in Germany. A total of 186 patients over 65 years with elective cardiac surgery were enrolled. Patients were randomized either to the intervention or control group. In both groups, postoperative delirium was assessed with the 3-min diagnostic interview for confusion assessment method on the first 5 days after surgery and pain was assessed using the Numeric Rating Scale. Multisensory stimulation was performed 20 min a day for the first three postoperative days in the intervention group.

RESULTS

The incidence of postoperative delirium was 22.6% in the intervention group and 49.5% in the control group (p < 0.001). Duration of postoperative delirium was significantly shorter in the intervention group (p < 0.001). Stay in the intensive care unit was significantly longer in the control group (p = 0.006). In the regression model non-intervention, high pain scores, advanced age, and prolonged mechanical ventilation were associated with postoperative delirium (p = 0.007; p = 0.032; p = 0.006; p = 0.006, respectively).

CONCLUSIONS

Results of the study imply that a multisensory stimulation done on the first 3 days after planned cardiac surgery can reduce the incidence and duration of postoperative delirium in older patients. Influence of the treatment on the incidence of delirium in other patient groups, the length of stay in the intensive care unit, and patients´ postoperative pain should be confirmed in further clinical studies.

TRIAL REGISTRATION

DRKS, DRKS00026909. Registered 28 October 2021, Retrospectively registered, https://drks.de/search/de/trial/DRKS00026909 .

Risk factors for delirium among hospitalized adults with COVID-19: A systematic review and meta-analysis of cohort studies

OBJECTIVES

This study aims to systematically assess the risk factors, the overall strength of association, and evidence quality related to delirium among adults hospitalized with COVID-19.

METHODS

A comprehensive search was conducted in thirteen databases from inception to February 10, 2023. The included databases were thoroughly searched, including PubMed, Web of Science, Proquest, Ovid MEDLINE, CINAHL, Scopus, the Cochrane Library, FMRS, Wanfang Database, Chinese Biomedical Database (CBM), China Knowledge Resource Integrated Database (CNKI), Weipu Database (VIP), and Embase. The search was limited to articles published in English and Chinese. The selected studies were screened, data were extracted, and the quality was evaluated using the Newcastle-Ottawa Scale. Meta-analysis was performed using RevMan 5.4 software. The certainty of the evidence was assessed using the GRADE criteria.

RESULTS

A total of 22 cohort studies with a sample size of 11,957 individuals were included in the analysis. Among these studies, 20 were of high quality, while the remaining 2 were of moderate quality. The risk factors that showed the strongest association with delirium were prior cognitive impairment (including dementia), mechanical ventilation, and ICU admission. Age, frailty (Clinical Frailty Scale score > 5), antipsychotic use, benzodiazepine use, neutrophil-to-lymphocyte ratio, and vasopressor use were identified as moderate risk factors for delirium. According to the GRADE evaluation, ICU admission, benzodiazepine use, neutrophil-to-lymphocyte ratio, and vasopressor use had a high-quality body of evidence, while antipsychotic usage had an intermediate-quality body of evidence. All other risk factors had a low-quality body of evidence.

CONCLUSIONS

This systematic review and meta-analysis identified several medium- to high-intensity risk factors for delirium in hospitalized adults with COVID-19. ICU admission, benzodiazepine usage, neutrophil-to-lymphocyte ratio, antipsychotic use, and vasopressor use were associated with delirium and were supported by medium- to high-quality evidence. These findings provide healthcare professionals with an evidence-based basis for managing and treating delirium in hospitalized adults with COVID-19.

Influence of Regional Nerve Block in Addition to General Anesthesia on Postoperative Delirium, Pain, and In-hospital Stay in Patients Undergoing Cardiothoracic Surgery: A Meta-analysis

ABSTRACT

This study aims to investigate whether venous injection of sedative agent or regional nerve block in alliance with major anesthesia could decrease the risk of postoperative delirium occurrence in patients receiving cardiothoracic surgery. Electronic academic databases were retrieved for related publications, and statistical software was used for data pooling and analysis. Forest plot was used to show the pooled sensitivity, specificity, and diagnostic odds ratio. Combined receiver operating characteristic curve was used to show the area under the curve of complex data. Seven studies were included for analysis. The risk of occurrence of delirium still showed no difference (risk rate = 0.93, 95% CI, 0.85-1.03) between the intervention group and placebo group. Postoperative pain feeling was more alleviated in patients with prophylactic application of regional nerve block. In addition, prophylactic application of regional nerve block could decrease the risk of postoperative in-hospital stay (risk rate = 0.28, 95% CI, 0.02-0.54). Our study demonstrated that, in elderly patients or pediatric patients undergoing cardiac surgery, prophylactic application of regional nerve block failed to decrease the incidence of postoperative delirium. However, the option of regional nerve block could decrease the duration of in-hospitalization stay and alleviate the acute pain during the postoperative period after open-heart surgery.

Delirium is associated with failure to rescue after cardiac surgery

Objective

Postoperative delirium after cardiac surgery is associated with long-term cognitive decline and mortality. We investigated whether increased ICU Confusion Assessment Method scores were associated with greater 30-day mortality and failure to rescue after cardiac surgery.

Methods

We studied 4030 patients who underwent a Society of Thoracic Surgeons index operation at the University of Virginia Health System from 2011 to 2021. We obtained all ICU Confusion Assessment Method scores recorded during patients' admission and summarized scores for the first 7 postoperative days. Univariate and multivariable logistic regression analyzed the association between ICU Confusion Assessment Method score/delirium presence and postoperative complications, operative mortality, and failure to rescue.

Results

Any episode of ICU Confusion Assessment Method screen-positive delirium and nearly all components of the score were associated with increased 30-day mortality on univariate analysis. We found that a single episode of delirium was associated with increased mortality. Feature 2 (inattention) had the strongest association with poorer outcomes, including failure to rescue in our analysis, as were patients with higher peak Richmond Agitation Sedation Scale scores. Patients with higher mean Richmond Agitation Sedation Scale scores had an association with decreased failure to rescue.

Conclusions

A single episode of delirium, as measured using ICU Confusion Assessment Method scores, is associated with increased mortality. Inattention and higher peak Richmond Agitation Sedation Scale scores were associated with failure to rescue. Screening may clarify diagnosing delirium and assessing its implications on mortality and failure to rescue. Our findings suggest the importance of identifying and managing risk factors for delirium to improve patient outcomes and reduce mortality and failure to rescue rates.

Cognitive Deficits in Executive and Language Functions Predict Postoperative Delirium

OBJECTIVES

Postoperative delirium (POD) remains the most common complication in older adults, with cognitive impairment being the main risk factor. Patients with mild cognitive impairment, in particular, have much to lose from delirium; despite this, their cognitive impairment might be clinically overlooked. Understanding which cognitive domains are particularly predictive in this regard may improve the sensitivity of preoperative testing and allow for a more targeted application of resource-intensive measures to prevent delirium in the perioperative period. The authors conducted this study with the aim of identifying the most indicative cognitive domains.

DESIGN

A secondary analysis of a randomized controlled trial.

SETTING

At a single center, the University Medical Centre Hamburg in Hamburg, Germany.

PARTICIPANTS

Patients ≥60 years without major neurocognitive disorders (dementia, Mini-Mental State Examination score ≤23) scheduled for cardiovascular surgery.

MEASUREMENTS AND MAIN RESULTS

Preoperative neuropsychologic testing and delirium screening were performed twice daily until postoperative day 5. A multiple logistic regression model was applied to determine the predictive ability of test performances for the development of delirium.

RESULTS

A total of 541 patients were included in the analysis; the delirium rate was 15.6%. After controlling for confounders, only low performance within the Trail Making Test B/A (odds ratio [OR] = 1.32; 95% CI: 1.05-1.66) and letter fluency (OR = 0.66; 95% CI: 0.45-0.96) predicted a particularly high risk for delirium development. The discriminative ability of the final multiple logistic regression model to predict POD had an area under the curve of 0.786.

CONCLUSIONS

Impairment in the cognitive domains of executive function and language skills associated with memory, inhibition, and access speed seem to be particularly associated with the development of delirium after surgery in adults ≥65 years of age without apparent preoperative neurocognitive impairment.

Development of postoperative delirium prediction models in patients undergoing cardiovascular surgery using machine learning algorithms

Associations between delirium and postoperative adverse events in cardiovascular surgery have been reported and the preoperative identification of high-risk patients of delirium is needed to implement focused interventions. We aimed to develop and validate machine learning models to predict post-cardiovascular surgery delirium. Patients aged ≥ 40 years who underwent cardiovascular surgery at a single hospital were prospectively enrolled. Preoperative and intraoperative factors were assessed. Each patient was evaluated for postoperative delirium 7 days after surgery. We developed machine learning models using the Bernoulli naive Bayes, Support vector machine, Random forest, Extra-trees, and XGBoost algorithms. Stratified fivefold cross-validation was performed for each developed model. Of the 87 patients, 24 (27.6%) developed postoperative delirium. Age, use of psychotropic drugs, cognitive function (Mini-Cog < 4), index of activities of daily living (Barthel Index < 100), history of stroke or cerebral hemorrhage, and eGFR (estimated glomerular filtration rate) < 60 were selected to develop delirium prediction models. The Extra-trees model had the best area under the receiver operating characteristic curve (0.76 [standard deviation 0.11]; sensitivity: 0.63; specificity: 0.78). XGBoost showed the highest sensitivity (AUROC, 0.75 [0.07]; sensitivity: 0.67; specificity: 0.79). Machine learning algorithms could predict post-cardiovascular delirium using preoperative data.Trial registration: UMIN-CTR (ID; UMIN000049390).

Predicting postoperative delirium after cardiovascular surgeries from preoperative portable electroencephalography oscillations

Introduction

Postoperative delirium (POD) is common and life-threatening, however, with intensive interventions, a potentially preventable clinical syndrome. Although electroencephalography (EEG) is a promising biomarker of delirium, standard 20-leads EEG holds difficulties for screening usage in clinical practice.

Objective

We aimed to develop an accurate algorithm to predict POD using EEG data obtained from portable device.

Methods

We recruited 128 patients who underwent scheduled cardiovascular surgery. Cognitive function assessments were conducted, and portable EEG recordings were obtained prior to surgery.

Results

Among the patients, 47 (36.7%) patients with POD were identified and they did not significantly differ from patients without POD in sex ratio, age, cognitive function, or treatment duration of intensive care unit. However, significant differences were observed in the preoperative EEG power spectrum densities at various frequencies, especially gamma activity, between patients with and without POD. POD was successfully predicted using preoperative EEG data with a machine learning algorithm, yielding accuracy of 86% and area under the receiver operating characteristic curve of 0.93.

Discussion

This study provides new insights into the objective and biological vulnerability to delirium. The developed algorithm can be applied in general hospitals without advanced equipment and expertise, thereby enabling the reduction of POD occurrences with intensive interventions for high-risk patients.

The risk factors of postoperative cognitive dysfunction in patients undergoing carotid endarterectomy: an updated meta-analysis

OBJECTIVE

The purpose of the current meta-analysis was to determine the incidence and risk factors to provide a scientific basis for prevention and treatment of postoperative cognitive dysfunction (POCD) after carotid endarterectomy (CEA).

METHODS

Relevant articles published before October 2022 were searched from Pubmed/MEDLINE, Cochrane and Embase databases. The outcomes were the incidence and risk factors for POCD. A random-effects model was applied to estimate the overall odds ratios (ORs) and mean differences (MDs) for all risk factors through STATA 14.0 and RevMan 5.4. The quality of eligible studies was evaluated by Newcastle-Ottawa Scale (NOS) as previously described.

RESULTS

A total of 22 articles involving 3459 CEA patients were finally identified. The weighted mean incidence of POCD was 19% (95% confidence intervals (95% CI) 0.16-0.24, P < 0.001). Of the 16 identified risk factors, hyperperfusion (OR: 0.54, 95% CI 0.41-0.71) and degree of internal carotid artery (ICA) stenosis (OR: 5.06, 95% CI 0.86-9.27) were the potential risk factors of POCD, whereas patients taking statins preoperative had a lower risk of POCD (OR: 0.54, 95% CI 0.41-0.71). Subgroup analysis revealed that the risk of POCD at 1 month after CEA was higher in patients with diabetes (OR: 1.70, 95% CI 1.07-2.71).

CONCLUSION

The risk factors of POCD were hyperperfusion and degree of ICA stenosis, while diabetes could significantly increase the incidence of POCD at 1 month after surgery. Additionally, preoperative statin use could be a protective factor for POCD following CEA.

Melatonin and Melatonin Agonists for Prevention of Delirium in the Cardiac Surgical ICU: A Meta-analysis

Aim and Background

Delirium is highly prevalent in the immediate postoperative period following cardiac surgery and adversely impacts outcomes. Melatonin has been increasingly used in pharmacological prevention of delirium. We aimed to synthesize the available evidence concerning the role of melatonin and melatonin agonists in preventing delirium in patients after cardiac surgery.

Materials and methods

PubMed, Google Scholar, and Web of Science databases were searched for relevant randomized and non-randomized trials in adults undergoing cardiac surgery investigating melatonin agonists to prevent delirium. Studies incorporating transplants, preoperative organ support, prophylactic antipsychotics, or children were excluded. Risk-of-bias was assessed using Cochrane ROB 2.0 and ROBINS-I tools. A systematic review and meta-analysis were conducted, calculating pooled odds ratio (OR) for the incidence of postoperative delirium using a random effects model with the Mantel-Haenszel method with restricted maximum-likelihood estimator. Trial sequential analysis was also carried out for the primary outcome.

Results

Six randomized trials and one non-randomized trial involving 1,179 patients were included. Incidence of delirium was 16.7 and 29.6% in the intervention and comparator groups respectively, indicating a pooled OR of 0.44 [95% confidence interval (CI) 0.27 - 0.71, p = 0.04] favoring melatonin. Two studies had a high risk of bias, and I2 statistics indicated significant heterogeneity. However, publication bias was insignificant, and trial sequential analysis indicated the significance of the attained effect size.

Conclusion

Based on available studies, perioperative melatonin use significantly decreases postoperative incidence of delirium after adult cardiac surgery. However, the available quality of evidence is low, and larger trials with standardization of nonpharmacological delirium prevention interventions, in high-risk cohorts, and exploring various dosages and regimens should be carried out.

How to cite this article

Niyogi SG, Naskar C, Singh A, Kumar B, Grover S. Melatonin and Melatonin Agonists for Prevention of Delirium in the Cardiac Surgical ICU: A Meta-analysis. Indian J Crit Care Med 2023;27(11):837-844.

Quantitative electroencephalography predicts postoperative delirium in cardiac surgical patients after cardiopulmonary bypass: a prospective observational study

Objective

Despite its frequency and associated negative effect, delirium remains poorly recognized in postoperative patients after ICU admission, especially among those who have undergone cardiac surgery with cardiopulmonary bypass. Postoperative delirium is triggered by a wide variety of acute medical conditions associated with impaired neuronal network connectivity. The lack of objective biomarkers primarily hinders the early detection of delirium. Seeking early biomarkers for tracking POD could potentially assist in predicting the onset of delirium and assessing the severity of delirium and response to interventions.

Methods

QEEGs were taken from 46 sedated postoperative patients, with 24 of them having undergone cardiac surgery. The assessment of delirium was performed twice daily using the Confusion Assessment Method for the ICU (CAM-ICU) to screen for postoperative delirium (POD). QEEG data were interpreted clinically by neurophysiologists and processed by open-source EEGLAB to identify features in patients who had or did not have POD after cardiac or non-cardiac surgery.

Results

The incidence of delirium in patients after undergoing cardiac surgery was nine times greater than in those after non-cardiac surgeries (41.7% vs. 4.5%; p = 0.0046). Patients with delirium experienced longer use of mechanical ventilation (118 h (78,323) compared to 20 h (18,23); p < 0.0001) and an extended ICU length of stay (7 days (6, 20) vs. 2 days (2, 4); p < 0.0001). The depth of anesthesia, as measured by RASS scores (p = 0.3114) and spectral entropy (p = 0.1504), showed no significant difference. However, notable differences were observed between delirious and non-delirious patients in terms of the amplitude-integrated EEG (aEEG) upper limit, the relative power of the delta band, and spectral edge frequency 95 (SEF95) (p = 0.0464, p = 0.0417, p = 0.0337, respectively).

Conclusion

In a homogenous population of sedated postoperative patients, robust qEEG parameters strongly correlate with delirium and could serve as valuable biomarkers for early detection of delirium and assist in clinical decision-making.

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.

Intra-operative electroencephalogram frontal alpha-band spectral analysis and postoperative delirium in cardiac surgery: A prospective cohort study

BACKGROUND

Postoperative delirium (POD) remains a frequent complication after cardiac surgery, with pre-operative cognitive status being one of the main predisposing factors. However, performing complete pre-operative neuropsychological testing is challenging. The magnitude of frontal electroencephalographic (EEG) α oscillations during general anaesthesia has been related to pre-operative cognition and could constitute a functional marker for brain vulnerability.

OBJECTIVE

We hypothesised that features of intra-operative α-band activity could predict the occurrence of POD.

DESIGN

Single-centre prospective observational study.

SETTING

University hospital, from 15 May 2019 to 15 December 2021.

PATIENTS

Adult patients undergoing elective cardiac surgery.

MAIN OUTCOME MEASURES

Pre-operative cognitive status was assessed by neuropsychological tests and scored as a global z score. A 5-min EEG recording was obtained 30 min after induction of anaesthesia. Anaesthesia was maintained with sevoflurane. Power and peak frequency in the α-band were extracted from the frequency spectra. POD was assessed using the Confusion Assessment Method for Intensive Care Unit, the Confusion Assessment Method and a chart review.

RESULTS

Sixty-five (29.5%) of 220 patients developed POD. Delirious patients were significantly older with median [IQR] ages of 74 [64 to 79] years vs. 67 [59 to 74] years; P  < 0.001) and had lower pre-operative cognitive z scores (-0.52 ± 1.14 vs. 0.21 ± 0.84; P  < 0.001). Mean α power (-14.03 ± 4.61 dB vs. -11.59 ± 3.37 dB; P  < 0.001) and maximum α power (-11.36 ± 5.28 dB vs. -8.85 ± 3.90 dB; P  < 0.001) were significantly lower in delirious patients. Intra-operative mean α power was significantly associated with the probability of developing POD (adjusted odds ratio, 0.88; 95% confidence interval (CI), 0.81 to 0.96; P  = 0.007), independently of age and only whenever cognitive status was not considered.

CONCLUSION

A lower intra-operative frontal α-band power is associated with a higher incidence of POD after cardiac surgery. Intra-operative measures of α power could constitute a means of identifying patients at risk of this complication.

TRIAL REGISTRATION

NCT03706989.

Association of general anesthesia exposure with risk of postoperative delirium in patients receiving transcatheter aortic valve replacement: a meta-analysis and systematic review

The aim of this meta-analysis was to assess the association of general anesthesia (GA) exposure with the risk of POD in this patient population. Databases including Medline, EMBASE, Cochrane library, and Google Scholar were searched from inception to December 2022. Analysis of 17 studies published between 2015 and 2021 involving 10,678 individuals revealed an association of GA exposure with an elevated risk of POD [odd ratio (OR) = 1.846, 95% CI 1.329 to 2.563, p = 0.0003, I2 = 68.4%, 10,678 patients]. Subgroup analysis of the diagnostic methods also demonstrated a positive correlation between GA exposure and POD risk when validated methods were used for POD diagnosis (OR = 2.199, 95% CI 1.46 to 3.31, p = 0.0002). Meta-regression analyses showed no significant impact of age, male proportion, and sample size on the correlation between GA and the risk of POD. The reported overall incidence of POD from the included studies regardless of the type of anesthesia was between 0.8 and 27%. Our meta-analysis showed a pooled incidence of 10.3% (95% CI 7% to 15%). This meta-analysis suggested an association of general anesthesia with an elevated risk of postoperative delirium, implying the necessity of implementing appropriate prophylactic strategies against this complication when general anesthesia was used in this clinical setting.

Associations between depression symptom burden and delirium risk: a prospective cohort study

BACKGROUND AND OBJECTIVES

Delirium and depression are increasingly common in aging. There is considerable clinical overlap, including shared symptoms and comorbid conditions, including Alzheimer's disease (AD), functional decline, and mortality. Despite this, the long-term relationship between depression and delirium remains unclear. This study assessed the associations of depression symptom burden and its trajectory with delirium risk in a 12-year prospective study of older individuals during hospitalization.

RESEARCH DESIGN AND METHODS

319,141 UK biobank participants between 2006-2010 (mean 58y [range 37-74, SD=8], 54% female) reported frequency (0-3) of four depressive symptoms (mood, disinterest, tenseness, or lethargy) in the preceding 2 weeks, and aggregated into a depressive symptom burden score (0-12). New-onset delirium was obtained from hospitalization records during 12y median follow-up. 40,451 (mean age 57±8; range 40-74y) had repeat assessment on average 8y after their first. Cox proportional hazard models examined whether depression symptom burden and trajectory predicted incident delirium during hospitalization.

RESULTS

5,753 (15 per 1000) newly developed delirium during follow-up. Increased risk for delirium was seen for mild (aggregated scores 1-2, hazards ratio, HR=1.16, [95% confidence interval 1.08-1.25], p<0.001), modest (scores 3-5, 1.30 [1.19-1.43], p<0.001) and severe (scores ≥ 5, 1.38 [1.24-1.55], p<0.001) depressive symptoms, versus none in the fully adjusted model. These findings were independent of the number of hospitalizations and consistent across hospitalization settings (e.g., surgical, medical, or critical care) and specialty (e.g., neuropsychiatric, cardiorespiratory or other). Worsening depression symptoms (≥1 point increase), compared to no change/improved score, were associated with an additional 39% increased risk (1.39 [1.03-1.88], p=0.03) independent of baseline depression burden. The association was strongest in those over 65y at baseline (p for interaction <0.001).

DISCUSSION AND IMPLICATIONS

Depression symptom burden and worsening trajectory predicted delirium risk during hospitalization. Increased awareness of subclinical depression symptoms may be warranted for delirium prevention.

Establishment of a nomogram for predicting prolonged mechanical ventilation in cardiovascular surgery patients

AIMS

This study aimed to develop a nomogram model for predicting prolonged mechanical ventilation (PMV) in patients undergoing cardiovascular surgery.

METHODS AND RESULTS

In total, 693 patients undergoing cardiovascular surgery at an Affiliated Hospital of Nantong University between January 2018 and June 2020 were studied. Postoperative PMV was required in 147 patients (21.2%). Logistic regression analysis showed that delirium [odds ratio (OR), 3.063; 95% confidence interval (CI), 1.991-4.713; P < 0.001], intraoperative blood transfusion (OR, 2.489; 95% CI, 1.565-3.960; P < 0.001), obesity (OR, 2.789; 95% CI, 1.543-5.040; P = 0.001), postoperative serum creatinine level (mmol/L; OR, 1.012; 95% CI, 1.007-1.017; P < 0.001), postoperative serum albumin level (g/L; OR, 0.937; 95% CI, 0.902-0.973; P = 0.001), and postoperative total bilirubin level (μmol/L; OR, 1.020; 95% CI, 1.005-1.034; P = 0.008) were independent risk factors for PMV. The area under the receiver operating characteristic curve for our nomogram was found to be 0.770 (95% CI, 0.727-0.813). The goodness-of-fit test indicated that the model fitted the data well (χ2 = 12.480, P = 0.131). After the model was internally validated, the calibration plot demonstrated good performance of the nomogram, as supported by the Harrell concordance index of 0.760. Decision curve analysis demonstrated that the nomogram was clinically useful in identifying patients at risk for PMV.

CONCLUSION

We established a new nomogram model that may provide an individual prediction of PMV. This model may provide nurses, social workers, physicians, and administrators with an accurate and objective assessment tool to identify patients at high risk for PMV after cardiovascular surgery.

Association between preoperative on-site CCU visits and postoperative delirium in patients undergoing cardiac surgery: A retrospective cohort study

BACKGROUND

Postoperative delirium (POD) is a common complication after cardiac surgery (CS), with symptoms like attention disorders and even delays patients' recovery.

AIMS

To evaluate the impact of preoperative on-site visits in the cardiac care unit (CCU) on POD after CS.

STUDY DESIGN

Patients admitted to the CCU with extracorporeal CS were included in the visiting or non-visiting group according to whether they were on visiting week. The visiting group received a preoperative visit from a nurse-led multidisciplinary visiting team (including CCU nurses and physicians) 1 week before surgery in addition to standard care. The non-visiting group received standard care like unstructured information from the CS team and anesthesiologists and so on. The Confusion Assessment Method for the ICU (CAM-ICU) and the Intensive Care Delirium Screening Checklist (ICDSC) were used to evaluate the POD severity. The incidence, occurrence and duration of POD, as well as the CCU length of stay, postoperative mechanical ventilation duration and length of hospital stay were compared between the two groups.

RESULTS

A total of 735 participants (369 in the visited group and 366 in the unvisited group) were included in this study. Preoperative on-site visits were associated with a decreased POD incidence (odds ratio [OR]: 0.524, 95% CI: 0.336-0.817), an improved POD severity (OR: 0.578, 95% CI: 0.359-0.932) and a shortening POD duration (OR: 0.972, 95% CI: 0.951-0.994). There was a significant difference between the visiting and non-visiting groups in the mechanical ventilation duration (OR: 0.987, 95% CI: 0.978-0.996).

CONCLUSIONS

Preoperative on-site visits are associated with a reduction in the incidence, duration, and severity of POD, as well as the mechanical ventilation duration of patients.

RELEVANCE TO CLINICAL PRACTICE

This study found that preoperative on-site visits were associated with the onset, duration, severity and duration of mechanical ventilation of POD. Although many factors influence the occurrence of POD, a multidisciplinary visiting team led by a nurse (including CCU nurses and physicians) can provide early nursing interventions through preoperative visits, better obtain postoperative cooperation from patients, establish a good nurse-patient relationship and provide better health services to patients. In a realistic CCU setting, nurses and physicians can act as educators, assessing patients before surgery, enhancing preoperative education, improving patient familiarity with the CCU environment and teaching sign language communication skills when patients are mechanically ventilated. These findings can therefore provide the basis for effective clinical care to prevent postoperative POD.

Intraoperative neurological pupil index and postoperative delirium and neurologic adverse events after cardiac surgery: an observational study

Neurological pupil index (NPi) calculated by automated pupillometry predicts clinical outcomes in critically ill patients. However, there are few data on intraoperative NPi and postoperative outcome after cardiac surgery. We evaluated the relationships between intraoperative NPi and clinical outcomes, such as delirium, in cardiac surgery patients. NPi was measured at baseline, after anesthesia induction, at 30 min intervals after initiation of cardiopulmonary bypass or anastomosis of coronary artery bypass graft, and at skin closure. Abnormal NPi was defined as one or more measurements of NPi < 3.0 during surgery. The worst intraoperative NPi was recorded, then multivariate logistic regression analysis was performed to evaluate the relationship between abnormal NPi and postoperative delirium following cardiac surgery. Among 123 included patients, postoperative delirium developed in 19.5% (24/123) of patients. Intraoperative abnormal NPi was significantly associated with postoperative delirium (odds ratio 6.078; 95% confidence interval 1.845-20.025; P = 0.003) after adjustment for Society of Thoracic Surgeons Predicted Risk of Mortality score, coronary artery disease, and use of calcium channel blockers. In conclusion, abnormal intraoperative NPi independently predicted postoperative delirium following cardiac surgery. Intraoperative application of pupillometry may have prognostic value for development of postoperative delirium, thereby enabling close surveillance and early intervention in high-risk patients.Registry number: ClinicalTrials.gov (NCT04136210).

Exploring the Frailty Components Related to Hospitalization-Associated Disability in Older Patients After Cardiac Surgery Using a Comprehensive Frailty Assessment

BACKGROUND

We investigated the components of frailty associated with hospitalization-associated disability (HAD) after cardiac surgery.

METHODS AND RESULTS

This retrospective, observational study evaluated 1,446 older patients after elective cardiac surgery at the Sakakibara Heart Institute. We examined the association between HAD and 7 domains of frailty assessed by the Kihon Checklist. HAD was defined as a decline in the ability to perform activities of daily living (ADL) between admission and discharge, as assessed by the Barthel Index. Logistic regression and decision tree analysis were used to identify associations between the number and type of frailty components and HAD. Of the 1,446 patients, 190 were excluded, and 90 (7%) developed HAD. An increase in the number of frailty components was a risk factor for HAD (odds ratio: 1.88, 95% confidence interval: 1.62-2.17). Decision tree analysis identified physical functional decline, depression, and cognitive dysfunction as factors associated with HAD. The incidence of HAD was highest in cases of physical functional decline (21%) and lowest for cases in which the 3 aforementioned factors were absent (2.8%).

CONCLUSIONS

An increased number of frailty factors increased the risk of HAD and the findings also reaffirmed the importance of a comprehensive assessment to evaluate the risk of HAD, including evaluation of physical function, cognitive function, and depression.

The Association of Infection with Delirium in the Post-Operative Period after Elective CABG Surgery

Delirium is one of the most common complications of coronary artery by-pass graft (CABG) surgery. The identification of patients at increased risk of delirium and the implementation of preventive measures to reduce the risk of postoperative delirium is necessary to improve treatment outcomes after CABG. The aim of this study was to assess the association between postoperative delirium and postoperative infection and 10-year mortality in patients undergoing CABG surgery. This is a retrospective, observational cohort study of patients undergoing planned on-pump CABG between April 2010 and December 2012. We analysed a group of 3098 patients operated on in our cardiac surgery centre, from whom we selected a cohort of patients undergoing planned CABG surgery. All patients were assessed for postoperative infection, such as pneumonia, bloodstream infections (BSIs) and surgical site infections (SSIs). Patients who experienced postoperative delirium were significantly more likely to have infection (7.4% vs. 22%; p = 0.0037). As regards particular types of infection, significant differences were only found for pneumonia and sternal SSIs. Patients who experienced postoperative delirium had significantly lower 5-year (p = 0.0136) and 10-year (p = 0.0134) survival. Postoperative delirium significantly increases long-term mortality in patients undergoing CABG surgery. Pneumonia and sternal SSIs significantly increase the risk of postoperative delirium in cardiac surgery patients.

Association between Plasma Ascorbic Acid Levels and Postoperative Delirium in Older Patients Undergoing Cardiovascular Surgery: A Prospective Observational Study

BACKGROUND

The incidence of delirium is high in older patients undergoing cardiovascular surgery with cardiopulmonary bypass (CPB). Intraoperative tissue hypoperfusion and re-reperfusion injury, which generate reactive oxygen species (ROS), are suggested to induce delirium. Ascorbic acid is an excellent antioxidant and may reduce organ damage by inhibiting the production of ROS. This prospective observational study aimed to measure pre- and postoperative plasma ascorbic acid levels and examine their association with delirium.

METHODS

Patients older than 70 years of age scheduled for elective cardiovascular surgery using CPB were enrolled. From September 2020 to December 2021, we enrolled 100 patients, and the data of 98 patients were analyzed.

RESULTS

In total, 31 patients developed delirium, while 67 did not. Preoperative plasma ascorbic acid levels did not differ between the non-delirium and delirium groups (6.0 ± 2.2 vs. 5.5 ± 2.4 µg/mL, p = 0.3). Postoperative plasma ascorbic acid levels were significantly different between the groups (2.8 [2.3-3.5] vs. 2.3 [1.6-3.3] µg/mL, p = 0.037).

CONCLUSIONS

In patients who undergo cardiovascular surgery with CPB, lower postoperative plasma ascorbic acid levels may be associated with the development of delirium.

[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.

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.