Incidence of and Risk Factors for Delirium After Cardiac Surgery at a Quaternary Care Center: A Retrospective Cohort Study

Incidence and relative risk of delirium after major surgery for patients with pre-operative depression: a systematic review and meta-analysis

BACKGROUND

Delirium is a common and potentially serious complication after major surgery. A previous history of depression is a known risk factor for experiencing delirium in patients admitted to the hospital, but the generalised risk has not been estimated in surgical patients.

METHODS

We conducted a systematic review and meta-analysis of studies reporting the incidence or relative risk (or relative odds) of delirium in the immediate postoperative period for adults with pre-operative depression. We included studies that defined depression as either a formal pre-existing diagnosis or having clinically important depressive symptoms measured using a patient-reported instrument before surgery. Multilevel random effects meta-analyses were used to estimate the pooled incidences and pooled relative risks. We also conducted subgroup analyses by various study-level characteristics to identify important moderators of pooled estimates.

RESULTS

Forty-two studies (n = 4,664,051) from five continents were included. The pooled incidence of postoperative delirium for patients with pre-operative depression was 29% (95%CI 17-43%, I2 = 99.0%), compared with 15% (95%CI 6-28%, I2 = 99.8%) in patients without pre-operative depression and 21% (95% CI 11-33%, I2 = 99.8%) in the cohorts overall. For patients with pre-operative depression, the risk of delirium was 1.91 times greater (95%CI 1.68-2.17, I2 = 42.0%) compared with patients without pre-operative depression.

CONCLUSIONS

Patients with a previous diagnosis of depression or clinically important depressive symptoms before surgery have substantially greater risk of experiencing delirium after surgery. Clinicians and patients should be informed of these increased risks. Robust screening and other risk mitigation strategies for postoperative delirium are warranted, especially for patients with pre-operative depression.

Delirium Knowledge, Risk Factors, and Attitude Among the General Public in Saudi Arabia: A Cross-Sectional Study

Introduction Delirium is a common and serious neuropsychiatric disorder, of acute onset, present at any age, but more common in older adults, and very common in clinical practice. It combines mental and behavioral symptoms with a fluctuating course, with worsening of the condition in the afternoon and at night, with important repercussions on increased mortality, greater risk of cognitive impairment, and hospitalization costs. Delirium's impact extends to patients, families, and healthcare systems, emphasizing the need for public awareness and education in Saudi Arabia. Methodology It is a cross-sectional conducted in Saudi Arabia that aims to assess knowledge, risk factors, and attitudes regarding delirium among all Saudi and non-Saudi residents aged 18 and older. A 36 self-administered questionnaire, standardized Nordic, was used. Data were cleaned in Microsft Excel (Microsoft Corporation, USA) and analyzed using IBM SPSS Statistics (IBM Corp., Armonk, NY). This study was conducted in Saudi Arabia from May 2023 till March 2024. Results Our study involved 1,470 participants from Saudi Arabia, primarily females (79.1%), Saudi nationals (89.9%), and unmarried individuals (65.4%). Most participants were aged 18-24 (59.5%) and held bachelor's degrees (57.3%). Commonly recognized delirium risk factors included increasing age (63.3%), dementia (58.2%), and longer ICU stays (48.7%). The participants showed moderate knowledge of delirium symptoms and consequences. Attitudes varied, with many agreeing that delirium requires intervention (30.7%) but fewer considering it preventable (17.1%). Sociodemographic factors, including gender and age, significantly influenced knowledge and attitudes, while education levels did not. Conclusion Our study found that gender and age influenced knowledge and attitudes, highlighting the importance of targeted education. Future research should further investigate the effectiveness of such interventions in enhancing knowledge and awareness and promoting preventive actions.

Feasibility of Goal-Directed Fluid Therapy in Patients with Transcatheter Aortic Valve Replacement - An Ambispective Analysis

INTRODUCTION

Goal-directed fluid therapy (GDFT) has been shown to reduce postoperative complications. The feasibility of GDFT in transcatheter aortic valve replacement (TAVR) patients under general anesthesia has not yet been demonstrated. We examined whether GDFT could be applied in patients undergoing TAVR in general anesthesia and its impact on outcomes.

METHODS

Forty consecutive TAVR patients in the prospective intervention group with GDFT were compared to 40 retrospective TAVR patients without GDFT. Inclusion criteria were age ≥ 18 years, elective TAVR in general anesthesia, no participation in another interventional study. Exclusion criteria were lack of ability to consent study participation, pregnant or nursing patients, emergency procedures, preinterventional decubitus, tissue and/or extremity ischemia, peripheral arterial occlusive disease grade IV, atrial fibrillation or other severe heart rhythm disorder, necessity of usage of intra-aortic balloon pump. Stroke volume and stroke volume variation were determined with uncalibrated pulse contour analysis and optimized according to a predefined algorithm using 250 ml of hydroxyethyl starch.

RESULTS

Stroke volume could be increased by applying GDFT. The intervention group received more colloids and fewer crystalloids than control group. Total volume replacement did not differ. The incidence of overall complications as well as intensive care unit and hospital length of stay were comparable between both groups. GDFT was associated with a reduced incidence of delirium. Duration of anesthesia was shorter in the intervention group. Duration of the interventional procedure did not differ.

CONCLUSION

GDFT in the intervention group was associated with a reduced incidence of postinterventional delirium.

Development and Validation of a Delirium Risk Prediction Model for Elderly Patients Undergoing Elective Orthopedic Surgery

Purpose

This study aimed to develop and validate a post-operative delirium (POD) nomogram in a population of elderly patients undergoing elective orthopedic surgery.

Patients and Methods

A predictive model was developed based on a training dataset of 474 elderly patients undergoing elective orthopedic surgery from March 2021 to May 2022. POD was identified using the Confusion Assessment Methods (CAM). The least absolute shrinkage and selection operator (LASSO) method was used to screen risk factors, and prediction models were created by combining the outcomes with logistic regression analysis. We employ bootstrap validation for internal validation to examine the model's repeatability. The results were validated using a prospective study on 153 patients operated on from January 2022 to May 2022 at another institution.

Results

The predictors in the POD nomogram included age, the Mini-Mental State Examination(MMSE), sleep disorder, neurological disorders, preoperative serum creatinine (Pre-SCR), and ASA classification. The c-index of the model was 0.928 (95% confidence interval 0.898 ~ 0.957) and the bootstrap validation still achieved a high c-index of 0.912. The c-index of the external validation was 0.921. The calibration curve for the diagnostic probability showed good agreement between prediction by nomogram and actual observation.

Conclusion

By combining preoperative and intraoperative clinical risk factors, we created a POD risk nomogram to predict the probability of POD in elderly patients who undergo elective orthopedic surgery. It could be a tool for guiding individualized interventions.

Dynamic predictive scores for cardiac surgery-associated agitated delirium: a single-center retrospective observational study

BACKGROUND

Prevention, screening, and early treatment are the aims of postoperative delirium management. The scoring system is an objective and effective tool to stratify potential delirium risk for patients undergoing cardiac surgery.

METHODS

Patients who underwent cardiac surgery between January 1, 2012, and January 1, 2019, were enrolled in our retrospective study. The patients were divided into a derivation cohort (n = 45,744) and a validation cohort (n = 11,436). The AD predictive systems were formulated using multivariate logistic regression analysis at three time points: preoperation, ICU admittance, and 24 h after ICU admittance.

RESULTS

The prevalence of AD after cardiac surgery in the whole cohort was 3.6% (2,085/57,180). The dynamic scoring system included preoperative LVEF ≤ 45%, serum creatinine > 100 µmol/L, emergency surgery, coronary artery disease, hemorrhage volume > 600 mL, intraoperative platelet or plasma use, and postoperative LVEF ≤ 45%. The area under the receiver operating characteristic curve (AUC) values for AD prediction were 0.68 (preoperative), 0.74 (on the day of ICU admission), and 0.75 (postoperative). The Hosmer‒Lemeshow test indicated that the calibration of the preoperative prediction model was poor (P = 0.01), whereas that of the pre- and intraoperative prediction model (P = 0.49) and the pre, intra- and postoperative prediction model (P = 0.35) was good.

CONCLUSIONS

Using perioperative data, we developed a dynamic scoring system for predicting the risk of AD following cardiac surgery. The dynamic scoring system may improve the early recognition of and the interventions for AD.

Developing prediction models for symptom severity around the time of discharge from a tertiary-care program for treatment-resistant psychosis

Antipsychotics are the only therapeutic class indicated in the symptomatic management of psychotic disorders. However, individuals diagnosed with schizophrenia or schizoaffective disorder may not always benefit from these first-line agents. This refractoriness to conventional treatment can be difficult to address in most clinical settings. Therefore, a referral to a tertiary-care program that is better able to deliver specialized care in excess of the needs of most individuals may be necessary. The average outcome following a period of treatment at these programs tends to be one of improvement. Nonetheless, accurate prognostication of individual-level responses may be useful in identifying those who are unlikely to improve despite receiving specialized care. Thus, the main objective of this study was to predict symptom severity around the time of discharge from the Refractory Psychosis Program in British Columbia, Canada using only clinicodemographic information and prescription drug data available at the time of admission. To this end, a different boosted beta regression model was trained to predict the total score on each of the five factors of the Positive and Negative Syndrome Scale (PANSS) using a data set composed of 320 hospital admissions. Internal validation of these prediction models was then accomplished by nested cross-validation. Insofar as it is possible to make comparisons of model performance across different outcomes, the correlation between predictions and observations tended to be higher for the negative and disorganized factors than the positive, excited, and depressed factors on internal validation. Past scores had the greatest effect on the prediction of future scores across all 5 factors. The results of this study serve as a proof of concept for the prediction of symptom severity using this specific approach.

Knowledge, attitude, and practice toward delirium and subtype assessment among Chinese clinical nurses and determinant factors: A multicentre cross-section study

Background

Delirium, a confused transient state of consciousness, can be divided into hyperactive, hypoactive, mixed, and no motor subtypes, according to different clinical manifestations. Several studies have investigated delirium subtypes in the knowledge dimension, but few studies have investigated delirium subtype in the attitude and practice dimensions. The barriers, knowledge sources, and practice details regarding subtype assessment are unclear.

Objectives

This study had three objectives. First, we planned to investigate the KAP status regarding delirium and subtypes for nurses. Second, we wanted to identify factors affecting clinical nurses' KAP scores. Third, this study expected to explore more details regarding delirium and subtypes assessment, including assessment barriers, assessment instruments, and knowledge sources.

Methods

This multicentre cross-section study was conducted in 10 tertiary hospitals in three provinces, China, from January to April 2022. We investigated 477 nurses from six departments with a high prevalence. The self-developed KAP questionnaire regarding delirium and subtypes assessment had four parts: knowledge, attitude, practice, and source. Its reliability and validity were verified effectively by 2-round Delphi expert consultation.

Results

A total of 477 nurses from the general intensive care unit (ICU), specialty ICU, orthopedics, thoracic surgery, operating room, and geriatrics were 28.3, 22.4, 22.2, 10.5, and 5.2%, respectively. The total KAP score regarding delirium and subtypes assessment was 60.01 ± 6.98, and the scoring rate was 73.18%. The scoring rate for knowledge, attitude, and practice was 58.55, 83.94, and 51.70%, respectively. More than half (54.1%) were unaware of the delirium subtypes assessment instruments. A total of 451 (94.6%) participants recognized the importance of nursing work for delirium prevention. A total of 250 (52.4%) nurses occasionally or sometimes assessed delirium subtypes, and 143 (30.0%) never assessed for delirium subtypes. We found that age, department, technical title, familiarity with delirium, familiarity with delirium subtypes, delirium training, and subtype training affected the total KAP scores. ICU nurses achieved the highest scores.

Conclusion

Chinese nurses' KAP status regarding delirium and subtypes assessment were barely acceptable, and the attitude score was positive, but knowledge and practice needed improvement. Meanwhile, the department was one of the significant KAP factors, and ICU nurses did better in delirium and subtype assessment in knowledge and practice dimension than other departments. Systematic and scientific training processes including subtype content and assessment tools are required. Experience still drives nurses' assessments of delirium and subtype. Adding the delirium assessment into routine tasks should be considered.

Identification of risk factors for delirium, cognitive decline, and dementia after cardiac surgery (FINDERI-find delirium risk factors): a study protocol of a prospective observational study

Background

Postoperative delirium is a common complication of cardiac surgery associated with higher morbidity, longer hospital stay, risk of cognitive decline, dementia, and mortality. Geriatric patients, patients undergoing cardiac surgery, and intensive care patients are at a high risk of developing postoperative delirium. Gold standard assessments or biomarkers to predict risk factors for delirium, cognitive decline, and dementia in patients undergoing cardiac surgery are not yet available.

Methods

The FINDERI trial (FINd DElirium RIsk factors) is a prospective, single-center, observational study. In total, 500 patients aged ≥ 50 years undergoing cardiac surgery at the Department of Cardiovascular and Thoracic Surgery of the University of Göttingen Medical Center will be recruited. Our primary aim is to validate a delirium risk assessment in context of cardiac surgery. Our secondary aims are to identify specific preoperative and perioperative factors associated with delirium, cognitive decline, and accelerated dementia after cardiac surgery, and to identify blood-based biomarkers that predict the incidence of postoperative delirium, cognitive decline, or dementia in patients undergoing cardiac surgery.

Discussion

This prospective, observational study might help to identify patients at high risk for delirium prior to cardiac surgery, and to identify important biological mechanisms by which cardiac surgery is associated with delirium. The predictive value of a delirium screening questionnaire in cardiac surgery might be revealed. Finally, the identification of specific blood biomarkers might help to predict delirium, cognitive decline, and dementia in patients undergoing cardiac surgery.

Trial registration: Ethics approval for this study was obtained from the IRB of the University of Göttingen Medical Center. The investigators registered this study in the German Clinical Trials Register (DRKS; https://www.drks.de) (DRKS00025095) on April 19th, 2021.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02732-4.

Early Serum Metabolism Profile of Post-operative Delirium in Elderly Patients Following Cardiac Surgery With Cardiopulmonary Bypass

Background

Cardiac surgery with cardiopulmonary bypass (CPB) is considered to be one of the surgical types with the highest incidence of post-operative delirium (POD). POD has been associated with a prolonged intensive care and hospital stay, long-term neurocognitive deterioration, and increased mortality. However, the specific pathogenesis of POD is still unclear. Untargeted metabolomics techniques can be used to understand the changes of serum metabolites in early POD to discover the relationship between serum metabolites and disease.

Materials and Methods

The present study recruited 58 elderly patients undergoing cardiac surgery with CPB. Serum was collected within the first 24 h after surgery. The Confusion Assessment Method (CAM) and ICU-CAM assessments were used to identify patients who experienced POD. All patients with normal post-operative cognitive assessment were included in the non-POD groups. Moreover, we collected serum from 20 healthy adult volunteers. We performed untargeted analyses of post-operative serum metabolites in all surgical groups, as well as serum metabolites in healthy non-surgical adults by using liquid chromatography mass spectrometry (LC/MS) and analyzed metabolic profiles and related metabolites.

Results

The probability of POD after cardiac surgery were 31%. There were statistically significant differences in post-operative mechanical ventilation time, ICU stay time and post-operative hospital stay between POD and non-POD group (P < 0.05). And ICU stay time was an independent risk factor for POD. The analysis revealed that a total of 51 differentially expressed metabolites (DEMs) were identified by comparing the POD and non-POD group, mostly lipids and lipid-like molecules. Three phosphatidylinositol (PI) were down-regulated in POD group, i.e., PI [18:0/18:2 (9Z, 12Z)], PI [20:4 (8Z, 11Z, 14Z, 17Z)/18:0], and PI [18:1 (9Z)/20:3 (8Z, 11Z, 14Z)]. The receiver operating characteristic (ROC) curve analysis showed that three kinds of PI metabolites had the highest area under the curve (AUC), which were 0.789, 0.781, and 0.715, respectively. Correlation analysis showed that the expression of three PIs was negatively correlated with the incidence of POD.

Conclusion

Our findings suggest that lipid metabolism plays an important role in the serum metabolic profile of elderly patients with POD in the early post-operative period. Low serum lipid metabolic PI was associated with incidence of POD in elderly following cardiac bypass surgery, which may provide new insights into the pathogenesis of POD.

Intraoperative Glycemic Variability and Mean Glucose are Predictors for Postoperative Delirium After Cardiac Surgery: A Retrospective Cohort Study

Purpose

Postoperative delirium (POD) is a common but serious complication after cardiac surgery and is associated with various short- and long-term outcomes. In this study, we investigated the effects of intraoperative glycemic variability (GV) and other glycemic variables on POD after cardiac surgery.

Patients and Methods

A retrospective single-center cohort analysis was conducted using data from electronic medical record from 2018 to 2020. A total of 705 patients undergoing coronary artery bypass graft surgery and/or valve surgery, and/or aortic replacement surgery were included in the analysis. Intraoperative GV was assessed with a coefficient of variation (CV), which was defined as the standard deviation of five intraoperative blood glucose measurements divided by the mean. POD assessment was performed three times a day in the ICU and twice a day in the ward until discharge by trained medical staff. POD was diagnosed if any of the Confusion Assessment Method for the Intensive Care Unit was positive in the ICU, and the Confusion Assessment Method was positive in the ward. Multivariable logistic regression was used to identify associations between intraoperative GV and POD.

Results

POD occurred in 306 (43.4%) patients. When intraoperative glycemic CV was compared as a continuous variable, the delirium group had higher intraoperative glycemic CV than the non-delirium group (22.59 [17.09, 29.68] vs 18.19 [13.00, 23.35], p < 0.001), and when intraoperative glycemic CV was classified as quartiles, the incidence of POD increased as intraoperative glycemic CV quartiles increased (first quartile 29.89%; second quartile 36.67%; third quartile 44.63%; and fourth quartile 62.64%, p < 0.001). In the multivariable logistic regression model, patients in the third quartile of intraoperative glycemic CV were 1.833 times (OR 1.833, 95% CI: 1.132–2.967, p = 0.014), and patients in the fourth quartile of intraoperative glycemic CV were 3.645 times (OR 3.645, 95% CI: 2.235–5.944, p < 0.001) more likely to develop POD than those in the first quartile of intraoperative glycemic CV.

Conclusion

Intraoperative blood glucose fluctuation, manifested by intraoperative GV, is associated with POD after cardiac surgery. Patients with a higher intraoperative GV have an increased risk of POD.

Relationship Between Cerebral Hemodynamics, Tissue Oxygen Saturation, and Delirium in Patients With Septic Shock: A Pilot Observational Cohort Study

Background: Septic shock patients have tendencies toward impairment in cerebral autoregulation and imbalanced cerebral oxygen metabolism. Tissue Oxygen Saturation (StO₂) and Transcranial Doppler (TCD) monitoring were undertaken to observe the variations of cerebral hemodynamic indices and cerebral/peripheral StO₂ to find risk factors that increase the sepsis-associated delirium (SAD). Materials and Methods: The research cohort was chosen from septic shock patients received in the Department of Critical Care Medicine, Xiangya Hospital, Central South University between May 2018 and March 2019. These patients were separated into two groups, SAD and non-SAD as assessed by using the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU). Comparisons were made between the two groups in terms of peripheral StO₂, fluctuations in regional cerebral oxygen saturation (rSO₂), cerebral vascular automatic regulation function [Transient Hyperemic Response Ratio (THRR) index], cerebral hemodynamic index, organ function indicators, blood gas analysis indices, and patient characteristics. Results: About 39% of the patients (20/51) suffered from SAD. Nearly 43% of the patients died within 28 days of admission (22/51). Individuals in the SAD cohort needed a longer period of mechanical ventilation [5 (95% CI 2, 6) vs. 1 days (95% CI 1, 4), p = 0.015] and more time in ICU [9 (95% CI 5, 20) vs. 5 days (95% CI 3, 9), p = 0.042]; they also experienced more deaths over the 28-day period (65 vs. 29%, p = 0.011). The multivariate regression analysis indicated that independent variables associated with SAD were THRR index [odds ratio (OR) = 5.770, 95% CI: 1.222-27.255; p = 0.027] and the mean value for rSO₂ was < 55% (OR = 3.864, 95% CI: 1.026-14.550; p = 0.046). Conclusion: Independent risk factors for SAD were mean cerebral oxygen saturation below 55% and cerebrovascular dysregulation (THRR < 1.09).

Postoperative delirium and quality of life after transcatheter and surgical aortic valve replacement: A prospective observational study

OBJECTIVE

In older patients, postoperative delirium is a frequently occurring complication after surgical aortic valve replacement, leading to an excess in postoperative morbidity and mortality. It remains controversial whether transcatheter aortic valve implantation and minimally invasive surgical aortic valve replacement can reduce the risk of postoperative delirium. This study aimed to compare the incidence of postoperative delirium after transcatheter aortic valve implantation and surgical aortic valve replacement and the impact on long-term outcomes.

METHODS

Between September 2018 and January 2020, we conducted an observational, prospective cohort study in patients aged 70 years or more undergoing transcatheter aortic valve implantation or surgical aortic valve replacement. The primary end point was the incidence of in-hospital postoperative delirium during 5 postoperative days assessed with the Confusion Assessment Method. Secondary end points included perioperative inflammation, postoperative complications, health status (EuroQol 5-dimensional questionnaire 5 levels), and mortality up to 6 months. Transcatheter aortic valve implantation and surgical aortic valve replacement were compared using propensity weighting to account for important baseline differences (European System for Cardiac Operative Risk Evaluation II, age, and frailty).

RESULTS

We included 250 patients with a mean (standard deviation) age of 80 (±5.8) years and a European System for Cardiac Operative Risk Evaluation score of 5 (±4.7). In the propensity-weighted analysis, those undergoing surgical aortic valve replacement (N = 166) had a higher incidence of postoperative delirium compared with transcatheter aortic valve implantation (N = 84) (51% vs 15%: P < .0001). Furthermore, patients undergoing surgical aortic valve replacement experienced more inflammation, a greater depth of anesthesia, and more intraoperative hypotension. After surgical aortic valve replacement, 41% of patients experienced an improved health status compared with 12% after transcatheter aortic valve implantation (P < .0001). No outcome differences were noted within the surgical aortic valve replacement groups.

CONCLUSIONS

Transcatheter aortic valve implantation is associated with a lower risk for postoperative delirium. Nevertheless, patients undergoing surgical aortic valve replacement experience the greatest improvement in quality of life. Heart teams should consider these outcomes in shared decision-making in the choice of transcatheter aortic valve implantation or surgical aortic valve replacement.

Depression as a predictor of postoperative delirium after cardiac surgery: a systematic review and meta-analysis

OBJECTIVES

Depression is common in patients with cardiac disease. The importance of preoperative depression for development of postoperative delirium (POD) following cardiac surgery is not well known. The aim is to provide a summary estimate of depression as a predictor of POD following cardiac surgery.

METHODS

Systematic search of MEDLINE, EMBASE, Cochrane Library, Web of Science Core Collection and Psycinfo (Ovid) was performed from inception to October 2019, including cohort studies reporting odds ratios (ORs) and 95% confidence intervals (CIs) for POD following cardiac surgery in patients with preoperative depression compared to patients without depression. ORs and 95% CIs for POD were calculated using random-effects meta-analyses. Subgroup and sensitivity analyses were performed.

RESULTS

Seven studies were included with a combined study population of 2066 patients. The pooled prevalence of POD in the combined study population was 26% and preoperative depression was present in ∼9% of the total study population. All studies showed a positive association between preoperative depression and POD; and in 5 studies, the association was statistically significant. Patients with depression had a pooled OR of 2.31 (95% CI 1.37-3.90) for POD.

CONCLUSIONS

This systematic review and meta-analysis confirm the findings that the previous association between preoperative depression and increased risk for developing POD reported for other patient groups is found also in cardiac surgery. Depression screening prior to cardiac surgery may be effective in identifying patients at higher risk for POD.

Development and validation of a delirium risk prediction preoperative model for cardiac surgery patients (DELIPRECAS): An observational multicentre study

STUDY OBJECTIVE

To develop and validate a delirium risk prediction preoperative model for patients undergoing cardiac surgery.

DESIGN

Observational prospective multicentre study.

SETTING

Six intensive care units in Spain.

PATIENTS

689 patients undergoing cardiac surgery consecutively, aged ≥18 years.

MEASUREMENTS

The primary outcome measure was the development of delirium, diagnosed using the Confusion Assessment Method in Intensive Care Units (CAM-ICU), during the stay in the intensive care unit after cardiac surgery.

MAIN RESULTS

The model was developed with 345 consecutive patients undergoing cardiac surgery at six hospitals and validated with another 344 patients from the same hospitals. The prediction model contained four preoperative risk factors: age over 65 years, Mini-Mental State Examination (MMSE) score of 25-26 points (possible impairment of cognitive function) or < 25 (impairment of cognitive function), insomnia needing medical treatment and low physical activity (walk less than 30 min a day). The model had an area under the receiver operating characteristics curve of 0.825 (95% confidence interval: 0.76-0.89). The validation resulted in an area under the curve of 0.79 (0.73-0.85) and the pooled area under the receiver operating characteristics curve (n = 689) was 0.81 (0.76-0.85). We stratified patients in groups of low (0%-20%), moderate (> 20%-40%), high (> 40%-60%) and very high (> 60%) risk of developing delirium, with a positive and negative predictive value for the very high risk group of 70.97% and 85.56%, respectively.

CONCLUSION

The DELIPRECAS model (DELIrium PREvention CArdiac Surgery), consisting of four well-defined clinical risk factors, can predict in the preoperative period the risk of developing postoperative delirium in patients undergoing cardiac surgery. An automatic version of the risk calculator is available.

Depression Predicts Delirium After Coronary Artery Bypass Graft Surgery Independent of Cognitive Impairment and Cerebrovascular Disease: An Analysis of the Neuropsychiatric Outcomes After Heart Surgery Study

OBJECTIVE

Although depression is a known risk factor for delirium after coronary artery bypass graft (CABG) surgery, it is unclear whether this risk is independent of delirium risk attributable to cognitive impairment or cerebrovascular disease. This study examines depression, mild cognitive impairment (MCI), and cerebrovascular disease as post-CABG delirium risk factors.

METHODS

This prospective observational cohort study was performed in a tertiary-care academic hospital. Subjects were without dementia and undergoing CABG surgery. Preoperative cognitive assessment included Clinical Dementia Rating and neuropsychological battery; depression was assessed using Depression Interview and Structured Hamilton. Baseline intracranial stenosis was evaluated by transcranial Doppler of bilateral middle cerebral arteries (MCAs). Study psychiatrists assessed delirium on postoperative days 2-5 using the Confusion Assessment Method.

RESULTS

Our analytic sample comprised 131 subjects (average age: 65.8 ± 9.2years, 27% women). MCI prevalence was 24%, preoperative depression 10%, lifetime depression 35%, and MCA stenosis (≥50%) 28%. Sixteen percent developed delirium. Multivariate analysis revealed that age, MCI (odds ratio [OR]: 5.1; 95% confidence interval [CI]: 1.3-20.1), and preoperative depression (OR: 9.9; 95% CI: 1.3-77.9)-but not lifetime depression-predicted delirium. MCA stenosis and severity predicted delirium in univariate but not multivariate analysis. Right MCA stenosis severity predicted delirium severity, but left-sided stenosis severity did not.

CONCLUSION

We established that the risk of delirium attributable to depression extends beyond the potential moderating influence of cognitive impairment and cerebrovascular disease alone. Even mild depression and cognitive impairment before CABG deserve recognition for their effect on post-CABG cognitive health.

Pharmacologic prevention of postoperative delirium after on-pump cardiac surgery: A meta-analysis of randomized trials

BACKGROUND

Postoperative delirium is a prevalent and disabling mental disorder in patients undergoing on-pump cardiac surgery. There is some evidence that the use of pharmacological interventions may reduce the risk of developing of postoperative delirium. Therefore, the aim of this meta-analysis was to determine the effect of pharmacologic agents for the prevention postoperative delirium after cardiac surgery.

METHODS

Randomized controlled trials (RCTs) were identified through a systematic literature search of electronic databases and article references up to October 2016. End points included incidence of postoperative delirium, severity of postoperative delirium, cognitive disturbances of postoperative delirium, duration of postoperative delirium, length of stay in intensive care unit (ICU) and hospital, and short-term mortality.

RESULTS

A total of 14 RCTs with an aggregate of 14,139 patients were included. The results of the present meta-analysis show that pharmacologic agents significantly decrease postoperative delirium [relative risk (RR), 0.83; 95% confidence interval (95% CI), 0.75-0.91, P < .00001] and duration of postoperative delirium (RR = -0.37, 95% CI = -0.47 to -0.27, P < .00001) after on-pump cardiac surgery. In addition, subgroup analysis shows that dexamethasone and dexamethasone were associated with a trend toward a reduction in postoperative delirium (RR, 0.45; 95% CI, 0.30-0.66, P < .0001; RR, 0.80; 95% CI, 0.68-0.93, P = .003, respectively). However, our results fail to support the assumption that pharmacologic prophylaxis is associated with a positively reduction in short-term mortality, length of ICU, or hospital stay.

CONCLUSION

This meta-analysis suggests that the perioperative use of pharmacologic agents can prevent postoperative delirium development in patients undergoing cardiac surgery. However, there remain important gaps in the evidence base on a few small studies with multiple limitations. Further large-scale, high-quality RCTs are needed in this area.

Delirium After Cardiac Surgery and Cumulative Fluid Balance: A Case-Control Cohort Study

OBJECTIVE

To assess a novel hypothesis to explain delirium after cardiac surgery through the relationship between cumulative fluid balance and delirium. This hypothesis involved an inflammatory process combined with a hypervolemic state, which could lead to venous congestion reaching the brain.

DESIGN

Retrospective case-control (1:1) cohort study.

SETTING

University-affiliated tertiary cardiology center.

PARTICIPANTS

Cardiac surgery intensive care unit (ICU) patients.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Cumulative fluid balance was evaluated at 3 times: (1) upon arrival at the ICU after surgery, (2) 24 hours post-ICU arrival, and (3) 48 hours post-ICU arrival. A generalized estimated equation was used to model the association between cumulative fluid balance and delirium occurrence 24 hours later. Covariates were selected based on the statistical differences between cases and controls on delirium risk factors and clinical characteristics. The cohort included 346 patients, of which 39 (11%), 104 (30%), and 142 patients (41%) presented delirium at 24, 48, and 72 hours post-ICU arrival, respectively. The effect of time had an odds ratio (OR) of 2.14, 95% confidence interval (CI) 1.603 to 2.851, and a p value < 0.001. The cumulative fluid balance was associated with delirium occurrence (OR 1.20, 95% CI: 1.066-1.355, p = .003). History of neurological disorder, having both hearing and visual impairment, type of procedure, perioperative cerebral oximetry, mean pulmonary artery pressure pre-cardiopulmonary bypass (CPB), and mean arterial pressure post-CPB also contributed to delirium in the model.

CONCLUSION

Delirium is associated with a cumulative fluid balance, but the extent through which this plays an etiologic role remains to be determined.

Effect of Preoperative Beta-Blocker Use on Outcomes Following Cardiac Surgery

Recent studies suggest that the use of preoperative β blockers in cardiac surgery may not provide improved mortality rates and may even contribute to negative clinical outcomes. We therefore assessed the role of β blockers on several outcomes after cardiac surgery (delirium, acute kidney injury [AKI], stroke, atrial fibrillation (AF), mortality, and hospital length of stay) in 4,076 patients who underwent elective coronary artery bypass grafting, coronary artery bypass grafting + valve, or valve cardiac surgery from November 1, 2009, to September 30, 2015, at Vanderbilt Medical Center. Clinical data from 2 prospectively collected datasets at our institution were reviewed: the Cardiac Surgery Perioperative Outcomes Database and the Society of Thoracic Surgeons Database. Preoperative β-blocker use was defined by Society of Thoracic Surgeons guidelines as patients receiving a β blocker within 24 hours preceding surgery. Of the included patients, 2,648 (65.0%) were administered a β blocker within 24 hours before surgery. Adjusting for possible confounders, preoperative β-blocker use was associated with increased odds of AKI stage 2 (odds ratio 1.96, 95% confidence interval 1.19 to 3.24, p <0.01). There was no evidence that β-blocker use had an independent association with postoperative delirium, AKI stages 1 and 3, stroke, AF, mortality, or prolonged length of stay. A secondary propensity score analysis did not show a marginal association between β-blocker use and any outcome. In conclusion, we did not find significant evidence that preoperative β-blocker use was associated with postoperative delirium, AF, AKI, stroke, or mortality.

Incidence of Postoperative Delirium and Its Impact on Outcomes After Transcatheter Aortic Valve Implantation

There are limited data on the occurrence of postoperative delirium after transcatheter aortic valve implantation (TAVI). We sought to investigate the incidence of delirium after TAVI and its impact on clinical outcomes. A total of 148 consecutive patients who underwent TAVI were enrolled. Of these patients, 141 patients survived hospital stay. The incidence of delirium was assessed in these patients for the first 4 days after the index procedure. The patients were divided into 2 groups based on the presence of delirium. Baseline characteristics, procedural and long-term outcomes, and frailty and quality-of-life indexes were compared among the groups. Of the 141 patients analyzed, 29 patients developed delirium. The transapical access was more common in patients with delirium (51.7% vs 8.9%, p <0.001). A greater median contrast volume load in the delirium group was noted (75 vs 100 ml, p = 0.001). Significantly more patients with delirium were considered as frail before TAVI. Thirty-day and 12-month all-cause mortality rates were higher in the delirium group (0.0% vs 17.2%, p <0.001; and 3.6% vs 37.9%, p <0.001, respectively). Differences in mortality were significant even after adjustment for baseline characteristics. The quality of life at 12 months, assessed by the 3-level version of the EuroQol 5-dimensional questionnaire, was similar in both groups. Despite a relatively minimally invasive character of TAVI as compared with surgery, some patients experience delirium after TAVI. Importantly, the occurrence of delirium after TAVI may help to identify patients with worse short- and long-term outcomes.

The prevalence of undiagnosed pre-surgical cognitive impairment and its post-surgical clinical impact in elderly patients undergoing surgery for adult spinal deformity

BACKGROUND

Pre-existing cognitive impairment (CI) is emerging as a predictor of poor post-operative outcomes in elderly patients. Little is known about impaired preoperative cognition and outcomes after elective spine surgery in this patient population. The purpose of this study was to assess the prevalence of neuro CI in elderly patients undergoing deformity surgery and its impact on postoperative outcomes.

METHODS

Elderly subjects undergoing elective spinal surgery for correction of adult degenerative scoliosis were enrolled in this study. Pre-operative baseline cognition was assessed using the Saint Louis Mental Status (SLUMS) test. SLUMS consists of 11 questions, which can give a maximum of 30 points. Mild CI was defined as a SLUMS score between 21-26 points, while severe CI was defined as a SLUMS score of ≤20 points. Normal cognition was defined as a SLUMS score of ≥27 points. Complication rates, duration of hospital stay, and 30-day readmission rates were compared between patients with and without baseline CI.

RESULTS

Eighty-two subjects were included in this study, with mean age of 73.26±6.08 years. Fifty-seven patients (70%) had impaired cognition at baseline. The impaired cognition group had the following outcomes: increased incidence of one or more postoperative complications (39% vs. 20%), higher incidence of delirium (20% vs. 8%), and higher rate of discharge institutionalization at skilled nursing or acute rehab facilities (54% vs. 30%). The length of hospital stay and 30-day hospital readmission rates were similar between both cohorts (5.33 vs. 5.48 days and 12.28% vs. 12%, respectively).

CONCLUSIONS

CI is highly prevalent in elderly patients undergoing surgery for adult degenerative scoliosis. Impaired cognition before surgery was associated with higher rates of post-operative delirium, complications, and discharge institutionalization. CI assessments should be considered in the pre-operative evaluations of elderly patients prior to surgery.

Risk factors for delirium after cardiac surgery: a historical cohort study outlining the influence of cardiopulmonary bypass

PURPOSE

Cardiopulmonary bypass (CPB) induces a significant inflammatory response that may increase the risk for delirium. We hypothesized that exposure to CPB during coronary artery bypass grafting (CABG) surgery would correlate with an increased risk of delirium.

METHODS

We reviewed clinical data from two databases at our medical centre - the Cardiac Surgery Perioperative Outcomes Database and the Society of Thoracic Surgeons Database. Patients undergoing elective CABG surgery (on-pump and off-pump) from November 1, 2009 to September 30, 2015 were included in the study. Delirium was defined as any postoperative positive Confusion Assessment Method for the Intensive Care Unit exam during the intensive care unit stay. We performed logistic regression to isolate the association between CPB exposure and delirium adjusted for predetermined risk factors and potential confounders.

RESULTS

During the study period, 2,280 patients underwent elective CABG surgery, with 384 patients (16.9%) exposed to CPB. Delirium was diagnosed in 451 patients (19.8%). Exposure to CPB showed a significant independent association with delirium. Patients exposed to CPB for 142 min (90^th percentile of CPB duration) vs those exposed for 54 min (10^th percentile) had an adjusted relative risk (RR) of delirium of 2.18 (95% confidence interval [CI], 1.39 to 3.07; P = 0.002) vs a RR of 1.51 (95% CI, 0.92 to 2.29; P = 0.10), respectively.

CONCLUSIONS

The use and duration of cardiopulmonary bypass were associated with an increased risk of delirium in patients undergoing CABG surgery.

TRIAL REGISTRATION

www.clinicaltrials.gov , NCT02548975. Registered 4 September 2015.

Current approach to diagnosis and treatment of delirium after cardiac surgery

Delirium after cardiac surgery remains a common occurrence that results in significant short- and long-term morbidity and mortality. It continues to be underdiagnosed given its complex presentation and multifactorial etiology; however, its prevalence is increasing given the aging cardiac surgical population. This review highlights the perioperative risk factors, tools to assist in diagnosing delirium, and current pharmacological and nonpharmacological therapy options.