A systematic review and meta-analysis of factors for delirium in vascular surgical patients

A Comprehensive Intervention Program for Postoperative Delirium Prevention in Elderly Patients Undergoing Cardiac Surgery

PURPOSE

To explore the application effect of a comprehensive intervention program for postoperative delirium (POD) prevention.

DESIGN

Descriptive and comparative study.

METHODS

This study included 82 elderly patients who underwent cardiac surgery as the control group to receive routine perioperative care. Seventy seven elderly patients who underwent cardiac surgery were selected as the observation group and received a comprehensive intervention program for POD prevention. This study further compared the length of stay in the hospital, nutritional status, pain score, and sleep quality between the two groups after intervention.

FINDINGS

The postoperative length of stay in the hospital of the observation group was shorter than that of the control group (12.60 ± 2.97 vs 17.30 ± 7.10), and the incidence of POD was lower than that of the latter group (24.68% vs 47.56%, X2 = 8.976, P = .003). The pain scores of the observation group were lower than those of the control group (F = 195.381, P < .001). There was significant difference that the sleep quality score of the observation group was higher than that of the control group (F = 219.20, P < .001). The levels of albumin and hemoglobin in the observation group were higher than those in the control group (54.38 ± 5.87 vs 38.40 ± 3.11; 124.64 ± 13.18 vs 109.00 ± 10.20). The observation group had shorter mechanical ventilation duration, intensive care unit stay, and lower total hospital expenses compared with the control group (P < .05).

CONCLUSIONS

The comprehensive intervention program for POD prevention based on evidence-based medicine has a positive effect. In addition, it can also improve patients' pain, sleep quality, and nutritional status.

Genetic Variation and Sex-Based Differences: Current Considerations for Anesthetic Management

Biomedical sciences have made immense progress and numerous discoveries aimed at improving the quality of life and life expectancy in modern times. Anesthesiology is typically tailored to individual patients as its clinical effects depend on multiple factors, including a patient's physiological and pathological states, age, environmental exposures, and genetic variations. Sex differences are also paramount for a complete understanding of the effects of specific anesthetic medications on men and women. However, women-specific research and the inclusion of women in clinical trials, specifically during child-bearing years, remain disproportionately low compared to the general population at large. This review describes and summarizes genetic variations, including sex differences, that affect responses to common anesthetic medications such as volatile anesthetics, induction agents, neuromuscular blocking drugs, opioids, and local anesthetics. It also discusses the influence of genetic variations on anesthesia outcomes, such as postoperative nausea and vomiting, allergic reactions, pain, depth of anesthesia, awareness under anesthesia and recall, and postoperative delirium.

Hypnotic drug use and intraoperative fluid balance associated with postoperative delirium following pancreatic surgery: A retrospective, observational, single-center study

BACKGROUND

Postoperative delirium is a common complication after various types of major surgery. The aim of this study was to identify risk factors associated with delirium following pancreatic surgery.

METHODS

Data from the patients who had pancreatic surgery between July 2020 and March 2021 in Ruijin Hospital affiliated with Shanghai Jiao Tong University School of Medicine were retrospectively analysed. The postoperative risk factors related to delirium were analyzed by univariate and multivariate Logistic regression analysis.

RESULTS

59 of 385 patients (15.3%) developed postoperative delirium after pancreatic surgery. The ROC curve revealed the optimal cutoff of intraoperative fluid balance was 2863ml. Furthermore, the multivariate analysis demonstrated that age ≥  65 years old [Odds ratio (OR) 2.01; 95% Confidence interval (CI) 1.12-3.63; p =  0.019], hypnotic drug use (OR 4.17; 95% CI 1.50-11.10; p =  0.005), and intraoperative fluid balance (OR 2.57; 95% CI 1.37-4.84; p =  0.003) were the independent risk factors of postoperative delirium.

CONCLUSION

This study identified that intraoperative fluid balance and hypnotic drug use were independent risk factors associated with postoperative delirium development after pancreatic surgery.

Cardiac surgery outcomes: The efficacy of dexmedetomidine in reducing postoperative delirium - A bibliometric study

Postoperative delirium (POD) is a prevalent complication following cardiac surgery, characterized by acute brain dysfunction observed in critically ill patients. Despite the significant impact of POD, there is currently no established treatment. Recent research has suggested that modulation of cholinergic neurotransmission and α2-adrenergic receptors may offer a therapeutic strategy for managing delirium during critical illness. This study employs bibliometric analysis to examine the emerging evidence on the role of dexmedetomidine, an α2-receptor agonist drug, in the prevention and treatment of POD. A systematic bibliometric analysis was conducted to identify and evaluate the literature on the use of dexmedetomidine in relation to POD. The study period spanned from 2006 to 2022, and the search was conducted in the Web of Science (WOS) database, focusing on relevant references. The analysis included the examination of the most frequent keywords, research trends, and frontiers to provide a comprehensive overview of the field. The bibliometric analysis revealed 160 research papers on the topic, indicating a significant increase in research output over the past decades. The field distribution, knowledge structure, and research topic evolution were identified as key areas of exploration. The analysis also highlighted the emergence of new topics and trends in the study of POD and its management. This bibliometric analysis provides a robust framework for understanding the current state of research on dexmedetomidine's efficacy in managing POD. It highlights the need for continued investigation and underscores the potential of this pharmacological approach to improve patient outcomes following cardiac surgery.

The Role of Cytokines in Perioperative Neurocognitive Disorders: A Review in the Context of Anesthetic Care

Perioperative neurocognitive disorders (PNDs), including postoperative delirium, delayed neurocognitive recovery, and long-term postoperative neurocognitive disorders, present significant challenges for older patients undergoing surgery. Inflammation is a protective mechanism triggered in response to external pathogens or cellular damage. Historically, the central nervous system (CNS) was considered immunoprivileged due to the presence of the blood-brain barrier (BBB), which serves as a physical barrier preventing systemic inflammatory changes from influencing the CNS. However, aseptic surgical trauma is now recognized to induce localized inflammation at the surgical site, further exacerbated by the release of peripheral pro-inflammatory cytokines, which can compromise BBB integrity. This breakdown of the BBB facilitates the activation of microglia, initiating a cascade of neuroinflammatory responses that may contribute to the onset of PNDs. This review explores the mechanisms underlying neuroinflammation, with a particular focus on the pivotal role of cytokines in the pathogenesis of PNDs.

Prehabilitation for delirium prevention in elderly patients with chronic limb threatening ischemia

OBJECTIVE

Elderly patients with chronic limb-threatening ischemia (CLTI) undergoing revascularization are prone to delirium and prolonged hospitalization. Preoperative prehabilitation may prevent delirium and reduce the length of stay. This study investigates the effect of multimodal prehabilitation on delirium incidence in elderly patients with CLTI undergoing revascularization.

METHODS

A comparative observational cohort study conducted in a large teaching hospital (intervention cohort n = 101, retrospective control cohort n = 207) and a university hospital (prospective control cohort n = 48) from 2020 to 2023. Patients aged ≥65 years undergoing revascularization were included, with acute treatment or severe cognitive impairment as exclusion criteria. The 3-week prehabilitation program included screening of general health and presence of delirium risk factors by a vascular nurse practitioner, screening and provision of personalized, home-based exercises by a physiotherapist, provision of nutritional advice by a dietician, and, if indicated, comprehensive geriatric assessment by a geriatrician, assessment of self-reliance and home situation by a prearranged homecare nurse, guidance and support for smoking cessation by a quit smoking coach, and anemia treatment. Primary outcome was 30-day delirium incidence, analyzed using regression models adjusting for potential confounders (age, physical impairment, history of delirium, preoperative anemia, and revascularization type). Secondary outcomes were length of stay, postoperative complications, 30-day mortality, and patient experiences.

RESULTS

Median age was 76 years (interquartile range [IQR], 71-82 years). Delirium incidence was lower in the prehabilitation cohort (n = 2/101; 2%) compared with controls (n = 23/255; 9%; odds ratio, 0.21; 95% confidence interval, 0.05-0.89; P = .04). Adjusted analysis showed a non-significant delirium reduction (odds ratio, 0.28; 95% confidence interval, 0.06-1.3; P = .097). The prehabilitation cohort had a significantly shorter length of stay (2 [IQR, 1-5] vs 4 [IQR, 2-9] days; P ≤ .001), and fewer minor complications (14% vs 26%; P=.01). No differences were present in major complications and 30-day mortality. Patients reported high compliance and satisfaction (median score, 8/10 [IQR, 7-9]).

CONCLUSIONS

Prehabilitation among elderly patients with CLTI is safe and has the potential to yield multiple beneficial effects on general outcomes following revascularization, while also achieving high levels of patient satisfaction. Further validation and consideration of implementation in surgical settings is recommended.

Study on the predictive model of delirium risk after surgery for elderly hip fractures based on meta-analysis

OBJECTIVE

To develop and validate a risk prediction model for postoperative delirium in elderly patients with hip fractures, aiming to identify high-risk patients and implement preventive measures.

METHODS

A systematic search of five authoritative medical databases was conducted, retrieving a total of 1368 relevant articles. After screening, 44 high-quality studies were included in the meta-analysis, analyzing 13 potential risk factors, such as age, gender, diabetes, and history of stroke. A risk prediction model was constructed and validated in a cohort of 189 elderly hip fracture patients. The model's predictive performance was evaluated using ROC curves, with calibration assessed through the Hosmer-Lemeshow test, and clinical utility examined via Decision Curve Analysis (DCA) and Clinical Impact Curves (CIC).

RESULTS

The meta-analysis identified the following as independent risk factors for postoperative delirium: age (≥ 70 years), male gender, diabetes, history of stroke, preoperative comorbidities (≥ 2), previous delirium, preoperative cognitive impairment, low preoperative albumin levels (≤ 40 g/L), prolonged preoperative waiting time (≥ 48 h), anemia (≤ 100 g/L), ASA classification (≥ 3), use of general anesthesia, and prolonged surgery duration (≥ 2 h). The prediction model demonstrated strong efficiency in the validation cohort, with an AUC of 0.956, sensitivity of 87.3%, specificity of 94.8%, and a Brier score of 0.144, indicating high predictive accuracy and calibration. DCA and CIC analyses showed the model to have strong clinical decision-making value and impact across most thresholds.

CONCLUSION

The risk prediction model developed in this study shows high predictive accuracy and clinical utility, making it valuable for identifying high-risk patients and implementing preventive measures in clinical practice. However, the study has limitations, such as potential retrospective bias, and further validation in larger, multicenter prospective studies is needed to confirm the model's broader applicability and stability.

Overtime work of anesthesiologists is associated with increased delirium in older patients admitted to intensive care unit after noncardiac surgery: a secondary analysis

BACKGROUND

Overtime work is common in anesthesiologists due to shortage of manpower. Herein, we analyzed if overtime work of anesthesiologists was associated with delirium development in older patients after surgery.

METHODS

This was a secondary analysis of the database from a randomized trial. Seven hundred older patients (aged ≥ 65 years) who were admitted to the intensive care unit (ICU) after elective noncardiac surgery were enrolled in the underlying trial. Anesthesiologists who worked continuously for more than 8 h by the end of the surgery were marked as "work overtime". Delirium was assessed with the Confusion Assessment Method for the ICU twice daily during the first 7 postoperative days. The association between overtime work of anesthesiologists and development of postoperative delirium was analyzed with multivariable logistic regression models.

RESULTS

All 700 patients (mean age 74.3 years, 39.6% female) were included in this analysis. Anesthesiologists of 281 patients (40.1%) were marked as "work overtime" at the end of surgery. When compared with patients whose anesthesiologists didn't work overtime, patients whose anesthesiologist worked overtime had a higher incidence of delirium within 7 days (20.3% [57/281] vs. 12.9% [54/419], P = 0.009). After correction for confounding factors, both overtime work (OR 1.87, 95% CI 1.19-2.94, P = 0.007) and prolonged continuous working hours of anesthesiologists (OR 1.08, 95% CI 1.01-1.15, P = 0.020) were associated with an increased risk of postoperative delirium.

CONCLUSIONS

Overtime work of anesthesiologists was associated with an increased risk of delirium development in older patients admitted to ICU after major noncardiac surgery.

TRIAL REGISTRATION

The underlying trial was registered with Chinese Clinical Trial Registry ( https://www.chictr.org.cn/showproj.html?proj=8734 ; ChiCTR-TRC-10000802; March 18, 2010).

Sex-Specific Validity of the PRE-DELIRIC Model and the E-PRE-DELIRIC Model for Predicting Delirium in Patients After Cardiac Surgery

BACKGROUND

Several risk prediction models are used in intensive care units (ICUs) to detect delirium risk.

OBJECTIVE

The aim of this study was to compare the sex-specific validity of the Prediction of Delirium in ICU patients (PRE-DELIRIC) and Early Prediction of Delirium in ICU patients (E-PRE-DELIRIC) models for predicting delirium in ICU patients after cardiac surgery.

METHODS

Retrospective data from electronic medical records of ICU patients who underwent cardiac surgery between January 2019 and December 2022 were examined. Both models were evaluated using sensitivity, specificity, and positive and negative predictive values based on the highest Youden index for female and male patients. Receiver operating characteristic curve analysis was performed.

RESULTS

Delirium incidence was 30.7% and 27.5% in female and male patients, respectively. In the PRE-DELIRIC model, the highest Youden index scores for female and male patients were 67.00 and 57.54, respectively, with sensitivities and specificities of 61% and 88%, and 72% and 79%, respectively. In the E-PRE-DELIRIC model, the highest scores for female and male patients were 14.25 and 14.05, with sensitivities and specificities of 78% and 50%, and 70% and 53%, respectively. The area under the curve of the PRE-DELIRIC model for female and male patients was 0.77 and 0.78, respectively, and that of the E-PRE-DELIRIC model was 0.67 and 0.63, respectively.

CONCLUSIONS

The PRE-DELIRIC model showed higher specificity and was more reliable for male patients, whereas the E-PRE-DELIRIC model demonstrated better sensitivity for female patients due to its inclusion of more female-sensitive factors. A combined approach is recommended for improved reliability and validity in delirium risk assessment in clinical settings.

A nomogram for predicting the risk of postoperative delirium in individuals undergoing cardiovascular surgery

BACKGROUND AND PURPOSE

Delirium is a common mental disorder after adult cardiovascular surgery. Fifteen to 23% of patients undergoing cardiovascular surgery and cardiomyopathy experience delirium, and the efficacy of treatment interventions for delirium has been consistently unsatisfactory.

METHODS

A total of 729 patients who underwent cardiovascular surgery were randomly allocated into a training set and a validation set. A nomogram was developed using a logistic regression model to predict the incidence of delirium following cardiovascular surgery. The validity of the model was assessed by determining the receiver operating characteristic (ROC) curve, calculating the area under the ROC curve (AUROC), performing a calibration plot, and executing a decision curve analysis. This model was internally validated using the bootstrap method.

RESULTS

Postoperative delirium (POD) occurred in 165 cases (22.6%) among the 729 patients. Predictors included age, transient ischemic attack, length of preoperative stay, preoperative left ventricular injection fraction and N-terminal pro-B-type natriuretic peptide level, and intraoperative infusion of dexmedetomidine and human fibrinogen. The nomogram showed sufficient differentiation and calibration (AUROC = 0.754, 95% confidence interval = 0.703-0.804). The calibration graphs showed that the predictive values of the nomogram were in agreement with the actual values. The analysis of the training and validation sets suggested that the model possessed specific clinical significance.

CONCLUSIONS

In summary, the predictive model consists of seven factors that can roughly predict the occurrence of POD in patients who undergo cardiovascular surgery.

Impact of the Charlson Comorbidity Index on Delirium Outcomes

Introduction Delirium is a significant inpatient healthcare challenge and has a greater incidence among older adults with adverse healthcare outcomes. Yet there are limited established models for risk stratification. The objective is to determine the effectiveness of implementing the Charlson comorbidity index (CCI) score, which is calculated based on the assigned weight for various disease conditions, and to analyze the healthcare outcomes in older hospitalized adults with delirium. Methodology A retrospective cohort study of 214 elderly hospitalized patients between January 1, 2015, and December 31, 2016, with the diagnosis of delirium, was analyzed by grouping based on the severity of diseases as defined in CCI. The primary analysis outcome was to analyze all-cause inpatient mortality, length of hospital stay (in days), 30-day readmissions, and discharge destination in patients with delirium based on CCI scores using regression analysis and nonparametric tests. Secondary analysis included the prevalence and characteristics of delirium patients in different severity levels of CCI. Results Patients with the severe CCI category (with a total score of five and above) spent 10 days longer in the hospital than those who were categorized with mild delirium (p = 0.011). There is a strong association between in-hospital mortality and the severe CCI category (odds ratio (OR), 4.566; 95% CI, 1.17- 1.86 (p = 0.035)). Also, patients with severe CCI scores were 4.6 times more likely to die during hospitalization compared to patients with less severe comorbidities. There were no significant differences found for discharge destination (OR, 0.702; 95% CI, 371- 1.328 (p = 0.277)) and readmission risk (OR, 1.660; 95% CI, 0.664- 4.149 (p = 0.278)) among different CCI groups.  Conclusions Length of stay and inpatient mortality were significantly higher among the severe CCI category compared to the mild category. Our study suggests that CCI can help clinicians, patients, and their families in prognostication and better understanding of goals of care conversations.

Prevalence and risk factors of postoperative delirium in tumor patients after free flap reconstruction: A systematic review and meta-analysis of case-control studies

BACKGROUND

Postoperative delirium is a severe complication of flap transplantation surgery, adversely affecting surgical prognoses. The intricate pathophysiology of postoperative delirium renders the elucidation of its risk factors challenging. This research aims to delineate the prevalence and the specific risk factors of postoperative delirium in patients with cancer undergoing free flap reconstruction through a systematic review and meta-analysis to enlighten proactive prevention measures.

METHODS

The researchers systematically queried both the international and Chinese databases. Searches were performed for publications from inception until September 14, 2023, using the terms "free tissue flaps," "delirium," "neoplasms," and "risk factors." Data synthesis and statistical analysis were conducted using Stata SE (version 15.0) to calculate the combined effect size for identified risk factors. Reported outcomes included weighted mean differences or odds ratios with their respective 95% confidence intervals.

RESULTS

Twelve case-control studies were included (ntotal = 3,256). Among them, 515 patients developed postoperative delirium after free flap surgery, compared with 2,741 patients who did not. The outcomes suggest that the risk factors include but are not limited to age, male, late neoplasm staging, use of hypnotic or antipsychotic, history of background diseases, psychiatric review, tracheotomy, and impaired wound healing. In contrast, early neoplasm staging and others are the protective factors with statistical significance. Multivariate analysis further identified significant correlations between preoperative albumin, perioperative blood transfusion, sleep disturbance, postoperative visual analog scale, postoperative albumin, smoking, and the appearance of postoperative delirium.

CONCLUSION

The determined risk factors were grouped into preoperative, intraoperative, and postoperative categories substantiated by current data to present instructions for postoperative delirium prevention.

The evaluation of frequency and predictors of delirium and its short-term and long-term outcomes in hospitalized older adults'

BACKGROUND

Delirium is a common complication in hospitalized older adults with multifactorial etiology and poor health outcomes.

AIM

To determine the frequency and predictors of delirium and its short-term and long-term outcomes in hospitalized older adults.

METHODS

A prospective observational study was performed in patients aged ≥60 years consecutively admitted to geriatric ward. Potential risk factors were assessed within 24 hours of hospital admission. Delirium screening was performed on admission and daily thereafter throughout the hospital stay using Confusion Assessment Method (CAM). Patients were followed up at 1-year post-discharge.

RESULTS

The study included 200 patients with mean age 73.1 ± 8.83 years. Incidence and prevalence rate of delirium were 5% and 20% respectively. Multivariable regression analysis revealed emergency admission (OR= 5.12 (1.94-13.57), p=0.001), functional dependency (Katz index of Independence in Activities of Daily Living (Katz-ADL) score <5) 2 weeks before admission (OR= 3.08 (1.30-7.33), p=0.011) and more psychopathological symptoms (higher Brief Psychiatric Rating Scale (BPRS) total score) (OR=1.12 (1.06-1.18), p=0.001) to be independently associated with delirium. Patients in delirium group had significantly high in-hospital mortality (OR= 5.02 (2.12-11.8), p=0.001) and post-discharge mortality (HR= 2.02 (1.13-3.61), p=0.017) and functional dependency (Katz-ADL score <5) (OR= 5.45 (1.49-19.31), p=0.01) at 1-year follow up.

CONCLUSION

Delirium is quite frequent in geriatric inpatients and is associated with high in-hospital and post-discharge mortality risk and long-term functional dependency. Emergency admission, pre-hospitalization functional dependency, and more general psychopathological symptoms are independently associated factors. Hence, earliest identification and treatment with early implementation of rehabilitation services is warranted.

The effect of anesthetic depth on postoperative delirium in older adults: a systematic review and meta-analysis

BACKGROUND

Postoperative delirium (POD) is an important complication for older patients and recent randomised controlled trials have showed a conflicting result of the effect of deep and light anesthesia.

METHODS

We included randomised controlled trials including older adults that evaluated the effect of anesthetic depth on postoperative delirium from PubMed, Embase, Web of Science and Cochrane Library. We considered deep anesthesia as observer's assessment of the alertness/ sedation scale (OAA/S) of 0-2 or targeted bispectral (BIS) < 45 and the light anesthesia was considered OAA/S 3-5 or targeted BIS > 50. The primary outcome was incidence of POD within 7 days after surgery. And the secondary outcomes were mortality and cognitive function 3 months or more after surgery. The quality of evidence was assessed via the grading of recommendations assessment, development, and evaluation approach.

RESULTS

We included 6 studies represented 7736 patients aged 60 years and older. We observed that the deep anesthesia would not increase incidence of POD when compared with the light anesthesia when 4 related studies were pooled (OR, 1.40; 95% CI, 0.63-3.08, P = 0.41, I2 = 82%, low certainty). And no significant was found in mortality (OR, 1.12; 95% CI, 0.93-1.35, P = 0.23, I2 = 0%, high certainty) and cognitive function (OR, 1.13; 95% CI, 0.67-1.91, P = 0.64, I2 = 13%, high certainty) 3 months or more after surgery between deep anesthesia and light anesthesia.

CONCLUSIONS

Low-quality evidence suggests that light general anesthesia was not associated with lower POD incidence than deep general anesthesia. And High-quality evidence showed that anesthetic depth did not affect the long-term mortality and cognitive function.

SYSTEMATIC REVIEW REGISTRATION

CRD42022300829 (PROSPERO).

A Lethal Combination of Delirium and Overcrowding in the Emergency Department

Delirium is a common public health concern that significantly impacts older patients admitted to the Emergency Department (ED). This condition is linked to adverse outcomes such as reduced long-term functionality, higher mortality rates, extended hospital stays, and increased medical costs. The identification of risk factors is crucial for the early recognition and management of delirium in ED patients. Aging, cognitive decline, polypharmacy, and sensory impairment are some of the most common general risk factors described in the literature. Although validated delirium assessment tools already exist, they are not practical for the fast-paced ED environment because of their extended evaluation period or specialized training request. Moreover, clear guidance is needed to select the most suitable tool for detecting delirium, balancing between the accuracy and the swiftness required in an overcrowded, high-stress, and understaffed healthcare setting. This narrative review aims to analyze the updated literature on delirium risk factors in older ED patients and focuses on the methods for better screening, managing, and treating this condition in the ED.

Does melatonin administration reduce the incidence of postoperative delirium in adults? Systematic review and meta-analysis

Postoperative delirium (POD) is common. It is associated with increased morbidity and mortality. Many cases may be preventable and melatonin offers promise as a preventative agent.

OBJECTIVE

This systematic review provides an up-to-date synthesis of the evidence on the effect of melatonin in preventing POD.

DESIGN

A systematic search of randomised controlled trials of melatonin in POD was run across multiple databases (EMBASE, MEDLINE, CINAHL, PsycINFO) and a clinical trials registry (ClinicalTrials.org) (1 January 1990 to 5 April 2022). Studies examining the effects of melatonin on POD incidence in adults are included. Risk of bias was assessed using the Cochrane risk of bias 2 tool.

OUTCOME MEASURES

The primary outcome is POD incidence. Secondary outcomes are POD duration and length of hospital stay. Data synthesis was undertaken using a random-effects meta-analysis and presented using forest plots. A summary of methodology and outcome measures in included studies is also presented.

RESULTS

Eleven studies, with 1244 patients from a range of surgical specialties were included. Seven studies used melatonin, in variable doses, and four used ramelteon. Eight different diagnostic tools were used to diagnose POD. Time points for assessment also varied. Six studies were assessed as low risk of bias and five as some concern. The combined OR of developing POD in the melatonin groups versus control was 0.41 (95% CI 0.21 to 0.80, p=0.01).

CONCLUSION

This review found that melatonin may reduce the incidence of POD in adults undergoing surgery. However, included studies displayed inconsistency in their methodology and outcome reporting. Further work to determine the optimum regime for melatonin administration, along with consensus of how best to evaluate results, would be beneficial.

PROSPERO REGISTRATION NUMBER

CRD42021285019.

The Relationship between Delirium and Statin Use According to Disease Severity in Patients in the Intensive Care Unit

Objective

The aim of this study was to investigate the association between the use of statins and the occurrence of delirium in a large cohort of patients in the intensive care unit (ICU), considering disease severity and statin properties.

Methods

We obtained clinical and demographical information from 3,604 patients admitted to the ICU from January 2013 to April 2020. This included information on daily statin use and delirium state, as assessed by the Confusion Assessment Method for ICU. We used inverse probability of treatment weighting and categorized the patients into four groups based on the Acute Physiology and Chronic Health Evaluation II score (group 1: 0-10 - mild; group 2: 11-20 - mild to moderate; group 3: 21-30 - moderate to severe; group 4: > 30 - severe). We analyzed the association between the use of statin and the occurrence of delirium in each group, while taking into account the properties of statins.

Results

Comparisons between statin and non-statin patient groups revealed that only in group 2, patients who were administered statin showed significantly higher occurrence of delirium (p = 0.004, odds ratio [OR] = 1.58) compared to the patients who did not receive statin. Regardless of whether statins were lipophilic (p = 0.036, OR = 1.47) or hydrophilic (p = 0.032, OR = 1.84), the occurrence of delirium was higher only in patients from group 2.

Conclusion

The use of statins may be associated with the increases in the risk of delirium occurrence in patients with mild to moderate disease severity, irrespective of statin properties.

Effect of intraoperative systemic magnesium sulphate on postoperative Richmond Agitation-Sedation Scale score after endovascular repair of aortic aneurysm under general anesthesia: A double-blind, randomized, controlled trial

Intraoperative magnesium has the effect of reducing postoperative opiate requirement, pain, and agitation. However, its effect on postoperative sedation and delirium is unclear. This study investigated the effect of magnesium on the postoperative Richmond Agitation-Sedation Scale (RASS) score and delirium following endovascular repair of aortic aneurysm (EVAR). Sixty-three consecutive patients diagnosed with abdominal (45) and thoracic (18) aortic aneurysm who underwent EVAR under general anesthesia were eligible. Patients were allocated randomly to the magnesium group (infusion of 30 mg•kg-1 magnesium in the first hour followed by 10 mg•kg-1 h-1 until the end of surgical procedure, targeting total 60 mg•kg-1) or the control group (0.9% saline at the same volume and rate). The primary outcome was whether magnesium had an effect on RASS score of patients at postoperative ICU admission. Secondary outcomes were effects on RASS score, numerical rating scale (NRS) score, Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) until 24 h after postoperative ICU transfer, and length of ICU stay. At postoperative ICU admission, magnesium had no significant effect on the RASS score (0[-0.5 to 0] vs 0[0 to 0]; P = 0.114), but at 1 h the NRS score was statistically different, 2[0 to 4] vs 4[0 to 5] (P = 0.0406). However, other data (RASS score, NRS score, CAM-ICU and length of ICU stay) did not show a significant difference. Our results did not show that intraoperative magnesium of target total 60 mg•kg-1 affected postoperative RASS score for undergoing EVAR. Trial registration: The current study was registered according to WHO and ICMJE standards on 4 July 2018, under registration number the Japan Registry of Clinical Trials, iRCTs041190013.

Melatonin for the prevention of postoperative delirium in older adults: a protocol for a systematic review and meta-analysis

INTRODUCTION

Postoperative delirium (POD) is a major cause of morbidity, particularly in elderly patients. Melatonin has been suggested as a low-risk pharmacological intervention to help prevent POD. A previous systematic review found limited high-quality evidence to support the use of melatonin in the prevention of POD. Several further randomised studies have since been published. This systematic review aims to synthesise the evidence from randomised controlled trials (RCTs) examining the effect of melatonin on the prevention of POD in older adults.

METHODS AND ANALYSIS

A systematic search of RCTs of melatonin (any dose and formulation) in POD will be run across Embase, Medline, CINAHL and PsychInfo. RCTs published from January 1990 until the end of February 2022 and reporting outcomes for melatonin use to prevent POD in patients will be included. Screening of search results and data extraction from included articles will be performed by two independent reviewers. The primary outcome will be incidence of POD in older adults undergoing surgery. Secondary outcomes are delirium duration and length of hospital stay. The review will also describe the dosage, timing and administration regimes of melatonin therapy and as well as the scales and definitions used to describe POD. A registry review of ongoing trials will be also be performed. For the meta-analysis, data will be pooled using a random effects model to generate a forest plot and obtain an odds ratio (OR) for the incidence of POD. Results will be reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

ETHICS AND DISSEMINATION

No ethical approval is required. This review will be disseminated via peer-reviewed manuscript and conferences. The results will be used as the basis of work to optimise this intervention for future trials in surgical populations.

PROSPERO REGISTRATION NUMBER

This review is registered with PROSPERO (CRD42021285019).

Development and validation of a nomogram to predict postoperative delirium in type B aortic dissection patients underwent thoracic endovascular aortic repair

Objective

Postoperative delirium (POD) is a common postoperative complication after cardiovascular surgery with adverse outcomes. No prediction tools are currently available for assessing POD in the type B aortic dissection (TBAD) population. The purposes of this study were to develop and validate a nomogram for predicting POD among TBAD patients who underwent thoracic endovascular aortic repair (TEVAR).

Methods

The retrospective cohort included 631 eligible TBAD patients who underwent TEVAR from January 2019 to July 2021. 434 patients included before 2021 were in the develop set; 197 others were in the independent validation set. Least absolute shrinkage and selection operator (LASSO) and logistic regression were applied to identify the most useful predictive variables for constructing the nomogram. Discrimination and the agreement of the model was assessed with the area under the receiver operating characteristic curve (AUC), Brier score and the Hosmer-Lemeshow goodness-of-fit test. The results were validated using a bootstrap resampling and the validation set.

Results

The incidence rate of POD observed in the development and validation cohort were 15.0% and 14.2%, respectively. Seven independent risk factors, including age ≥60 years, syncope or coma, postoperative blood transfusion, atelectasis, estimated glomerular filtration rate (eGFR) &lt;80 ml/min/1.73 m2, albumin &lt;30 g/L, and neutrophil to lymphocyte ratio, were included in the nomogram. The model showed a good discrimination with an AUC of 0.819 (95% CI, 0.762–0.876) in the developed set, and adjusted to 0.797 (95% CI, 0.735–0.849) and 0.791 (95% CI, 0.700–0.881) in the internal validation set and the external validation, respectively. Favorable calibration of the nomogram was confirmed in both the development and validation cohorts.

Conclusion

The nomogram based on seven readily available predictors has sufficient validity to identify POD risk in this population. This tool may facilitate targeted initiation of POD preventive intervention for healthcare providers.

Delirium in hospitalised adults with acute burns - A systematic review

INTRODUCTION

Delirium is a potentially modifiable, acutely altered mental state, commonly characterised as a hospital-acquired complication. Studies of adult inpatients with acute burns with and without delirium identify causative risks related to the injury or treatment and outcomes related to the patient and healthcare system. We compare patients with and without delirium, providing a high-level quantitative synthesis of delirium risks and outcomes to inform guidelines and future research.

METHODS

A systematic review, meta-analysis and GRADE evaluation of risks and outcomes associated with delirium in adults with acute burns was conducted using PRISMA guidelines and PROSPERO protocol CRD42021283055. The Newcastle-Ottawa Scale was used to assess quality.

RESULTS

Investigators reviewed ten studies. ASA score ≥ 3, Total Body Surface Area Percentage (TBSA)> 10%, surgery done, ICU admission, hospital and also Intensive Care Unit (ICU) lengths of stay all had statistically significant associations with delirium, with low-very low certainty on GRADE evaluation. Limitations were heterogeneous studies, review methodology and study bias.

CONCLUSION

Delirium represents a significant risk to comorbid patients with burns that are hospitalised, receive ICU care, and surgery. Further research is indicated to precisely categorise delirium along the clinical journey to identify modifiable factors, prevention, and proactive therapy.

Perioperative neurocognitive disorders: A narrative review focusing on diagnosis, prevention, and treatment

Perioperative neurocognitive disorders (NCDs) refer to neurocognitive abnormalities detected during the perioperative periods, including preexisting cognitive impairment, preoperative delirium, delirium occurring up to 7 days after surgery, delayed neurocognitive recovery, and postoperative NCD. The Diagnostic and Statistical Manual of Mental Disorders‐5th edition (DSM‐5) is the golden standard for diagnosing perioperative NCDs. Given the impracticality of using the DSM‐5 by non‐psychiatric practitioners, many diagnostic tools have been developed and validated for different clinical scenarios. The etiology of perioperative NCDs is multifactorial and includes predisposing and precipitating factors. Identifying these risk factors is conducive to preoperative risk stratification and perioperative risk reduction. Prevention for perioperative NCDs should include avoiding possible contributors and implementing nonpharmacologic and pharmacological interventions. The former generally includes avoiding benzodiazepines, anticholinergics, prolonged liquid fasting, deep anesthesia, cerebral oxygen desaturation, and intraoperative hypothermia. Nonpharmacologic measures include preoperative cognitive prehabilitation, comprehensive geriatric assessment, implementing fast‐track surgery, combined use of regional block, and sleep promotion. Pharmacological measures including dexmedetomidine, nonsteroidal anti‐inflammatory drugs, and acetaminophen are found to have beneficial effects. Nonpharmacological treatments are the first‐line measures for established perioperative NCDs. Pharmacological treatments are still limited to severely agitated or distressed patients.

Multicomponent Prehabilitation as a Novel Strategy for Preventing Delirium in Older Chronic Limb Threatening Ischemia Patients: A Study Protocol

Objective

Chronic limb threatening ischemia is the final stage of peripheral arterial disease. Current treatment is based on revascularization to preserve the leg. In the older, hospitalized chronic limb threatening ischemia patient, delirium is a frequent and severe complication after revascularization. Delirium leads to an increased length of hospital stay, a higher mortality rate and a decrease in quality of life. Currently, no specific guidelines to prevent delirium in chronic limb threatening ischemia patients exist. We aim to evaluate the effect of a multicomponent, multidisciplinary prehabilitation program on the incidence of delirium in chronic limb threatening ischemia patients ≥65 years.

Design

A prospective observational cohort study to investigate the effects of the program on the incidence of delirium will be performed in a large teaching hospital in the Netherlands. This manuscript describes the design of the study and the content of this specific prehabilitation program.

Methods

Chronic limb threatening ischemia patients ≥65 years that require revascularization will participate in the program. This program focuses on optimizing the patient's overall health and includes delirium risk assessment, nutritional optimization, home-based physical therapy, iron infusion in case of anaemia and a comprehensive geriatric assessment in case of frailty. The primary outcome is the incidence of delirium. Secondary outcomes include quality of life, amputation-free survival, length of hospital stay and mortality. Exclusion criteria are the requirement of acute treatment or patients who are mentally incompetent to understand the procedures of the study or to complete questionnaires. A historical cohort from the same hospital is used as a control group.

Discussion

This study will clarify the effect of a prehabilitation program on delirium incidence in chronic limb threatening ischemia patients. New insights will be obtained on optimizing a patient's preoperative mental and physical condition to prevent postoperative complications, including delirium.

Trial

This protocol is registered at the Netherlands National Trial Register (NTR) number: NL9380.

A systematic review of strategies for preventing delirium in patients undergoing vascular surgery

OBJECTIVES

Elderly patients undergoing vascular surgery are at risk of developing postoperative delirium, which is associated with a high mortality. Delirium prevention is difficult and is investigated in surgical patients from various specialisms, but little is known about delirium prevention in vascular surgery. For this reason we performed a systematic review on strategies for delirium prevention in patients undergoing elective surgery for peripheral arterial disease or for an aneurysm of the abdominal aorta.

METHODS

This systematic review included studies describing strategies for preventing delirium in patients undergoing elective surgery for peripheral arterial disease or for an aneurysm of the abdominal aorta. The search was conducted using the keywords 'vascular surgery', 'prevention' and 'delirium', and was last run on October 21st, 2021 in the electronic databases Pubmed, MEDLINE, Embase, Web of Science, the Cochrane library and Emcare. Risk of bias was assessed using the Cochrane Risk of Bias tool for randomized controlled trials and the ROBINS-1 tool for observational studies.

RESULTS

Four studies including 565 patients were included in the systematic review. A significant decrease in the incidence of delirium was reported by a study investigating the effect of comprehensive geriatric assessments within patients undergoing surgery for an aneurysm of the abdominal aorta or lower limb bypass surgery (24% in the control group versus 11% in the intervention group, p = 0.018), and in the total group of a study evaluating the effect of outpatient clinic multimodal prehabilitation for patients with an aneurysm of the abdominal aorta (11.7% in the control group versus 8.2% in the intervention group, p = 0.043, OR = 0.56). A non-significant decrease in delirium incidence was described for patients receiving a multidisciplinary quality improvement at the vascular surgical ward (21.4% in the control group versus 14.6% in the intervention group, p = 0.17). The study concerning the impact of the type of anaesthesia on delirium in eleven older vascular surgical patients, of which three developed delirium, did not differentiate between the different types of anaesthesia the patients received.

CONCLUSION

Despite the high and continuous increasing incidence of delirium in the growing elderly vascular population, little is known about effective preventive strategies. An approach to address multiple risk factors simultaneously seems to be promising in delirium prevention, whether through multimodal prehabilitation or comprehensive geriatric assessments. Several strategies including prehabilitation programs have been proven to be successful in other types of surgery and more research is required to evaluate effective preventive strategies and prehabilitation programs in vascular surgical patients.

Incidence, Predictors and Outcomes of Delirium in Complicated Type B Aortic Dissection Patients After Thoracic Endovascular Aortic Repair

Purpose

The present study aimed to investigate the incidence and predictors of post-operative delirium (POD) in patients with complicated type B aortic dissection (TBAD) undergoing TEVAR with/without concomitant procedures and to assess the association of POD with early and follow-up outcomes.

Methods

A retrospective single-center cross-sectional analysis was conducted using a prospectively maintained database from 2010 to 2017. Outcomes were postoperative clinical outcomes, early and follow-up survival.

Results

A total of 517 complicated TBAD patients were enrolled. POD was observed in 13.3% (69/517) patients and was associated with increased hospital length of stay (LOS) and hospital costs (P< 0.001 for both). Besides, POD was found to be an independent risk factor for prolonged ICU stay (odds ratio [OR] 4.39, 95% confidence interval [CI] 2.40–8.01, P< 0.001) and early death (OR 4.42, 95% CI 1.26–15.54, P= 0.020). Predictors of POD were hybrid procedure (OR 2.17, 95% CI 1.20–3.92, P= 0.010), the use of benzodiazepine (OR 1.86, 95% CI 1.07–3.23, P= 0.027) or quinolone (OR 2.35, 95% CI 1.26–4.38, P= 0.007), creatinine >2 mg/dL (OR 3.25, 95% CI 1.57–6.72, P= 0.001) and preoperative blood transfusion (OR 3.31, 95% CI 1.76–6.21, P< 0.001). After a median follow-up of 73.6 months, POD remained as an independent indicator for follow-up mortality (hazard ratio [HR] 2.40, 95% CI 1.31–4.38, P= 0.005) after adjusting potential confounders.

Conclusion

POD after TEVAR has an incidence of around 13% and could profoundly increase the in-hospital LOS, hospital costs, as well as the early and follow-up mortality. A series of risk factors, including hybrid procedure, the use of benzodiazepine or quinolone, creatinine >2 mg/dL and preoperative blood transfusion, were identified as independent risk factors for POD. Effective risk-stratification and patient-tailored management strategy should be developed to reduce the incidence of POD.

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

BACKGROUND

Postoperative delirium (POD) is associated with increased mortality, increased length of hospital stays and increased rates and severity of subsequent cognitive decline including dementia. A wide range of risk factors for POD have been suggested in the literature across multiple surgical specialities. However few are validated and no accurate prognostic models exist. We therefore aimed to map the existing evidence regarding risk factors for POD to help guide future research by undertaking an umbrella review of systematic reviews examining risk factors for POD in any context.

MATERIALS AND METHODS

We systematically searched multiple medical databases for systematic reviews examining the risk factors for POD in adults undergoing any surgery. We then selected relevant reviews with minimal overlap in primary studies and extracted information about individual risk factors.

RESULTS

Thirty-five relevant reviews were identified of which ten were in trauma and orthopaedic surgery patients (four exclusively examined hip fractures), five were in cardiac surgery patients, and four were in vascular surgery patients. Due to substantial overlap in reviews, eighteen reviews were analysed in detail finding the widely examined and consistent risk factors were increasing age, nursing home residency, pre-existing cognitive impairment, psychiatric disorders, cerebrovascular disease, end stage renal failure, low albumin, higher ASA score, and intra-operative blood transfusion. Many other risk factors were examined, but they were either not studied in multiple systematic reviews, or inconsistent either in results or in categorisation (which for many factors was heterogenous even within systematic reviews). There are also a large number of existing prognostic models, many of which remain unvalidated.

CONCLUSION

Given the wealth of existing literature, future research should avoid simple risk factor evaluation except for novel candidates, validate existing prognostic models where possible, and instead focus on interventional research.

Delirium Prevention in Postcardiac Surgical Critical Care

This review provides an overview for health care teams involved in the perioperative care of cardiac surgery patients. The intention is to summarize key determinants of delirium, its impact on short- and long-term outcomes as well as to discuss effective management strategies. The first component of this review examines the prevalence and the factors associated with an increased risk of postoperative delirium. A multitude of predisposing (eg, baseline vulnerability and comorbidities) and precipitating (eg, type of cardiac surgery and postoperative care) factors that contribute to the occurrence of delirium are discussed.

Presurgical Screening Improves Risk Prediction for Delirium in Elective Surgery of Older Patients: The PAWEL RISK Study

Introduction: The number of elective surgeries for patients who are over 70 years of age is continuously growing. At the same time, postoperative delirium (POD) is common in older patients (5–60%) depending on predisposing risk factors, such as multimorbidity, cognitive impairment, neurodegenerative disorders and other dementing disorders, and precipitating factors, such as duration of surgery. Knowledge of individual risk profiles prior to elective surgery may help to identify patients at increased risk for development of POD. In this study, clinical and cognitive risk factors for POD were investigated in patients undergoing various elective cardiac and non-cardiac surgeries.

Methods: The PAWEL study is a prospective, interventional trial on delirium prevention. At baseline, 880 inpatients at five surgical centers were recruited for sub-sample PAWEL-R. Multimodal assessments included clinical renal function, medication, American Society of Anesthesiologists (ASA) Physical Status Classification System, geriatric and cognitive assessments, which comprised the Montreal Cognitive Assessment Scale (MoCA), Trail-making Test, and Digit Span backward. Delirium incidence was monitored postoperatively by the Confusion Assessment Method (CAM) and a chart review for up to a week or until discharge. Multivariate regression models and Chi-square Automatic Interaction Detectors (CHAID) analyses were performed using delirium incidence as the primary outcome.

Results: Eighteen risk factors were investigated in elective cardiovascular and orthopedic or general surgery. A total of 208 out of 880 patients (24%) developed POD. A global regression model that included all risk variables predicted delirium incidence with high accuracy (AUC = 0.81; 95% CI 0.77, 0.85). A simpler model (clinical and cognitive variables; model CLIN-COG) of 10 factors that only included surgery type, multimorbidity, renal failure, polypharmacy, ASA, cut-to-suture time, and cognition (MoCA, Digit Span backward, and preexisting dementia), however, exhibited similar predictive accuracy (AUC = 0.80; 95% CI 0.76, 0.84).

Conclusion: The risk of developing POD can be estimated by preoperative assessments, such as ASA classification, expected cut-to-suture time, and short cognitive screenings. This rather efficient approach predicted POD risk over all types of surgery. Thus, a basic risk assessment including a cognitive screen can help to stratify patients at low, medium, or high POD risk to provide targeted prevention and/or management strategies for patients at risk.

Association between ankle brachial index and development of postoperative intensive care unit delirium in patients with peripheral arterial disease

Patients with vascular diseases are prone to developing postoperative delirium (POD). Ankle brachial index (ABI) is a non-invasive clinical indicator of lower-extremities peripheral arterial disease (PAD) and has been identified as an indicator of cognitive impairment. We investigated the association between ABI and POD. 683 PAD patients who underwent elective leg arterial bypass surgery between October 1998 and August 2019 were collected for retrospective analysis. Demographic information, comorbidities, preoperative ABI and the Rutherford classification within one month prior to surgery were obtained. POD was assessed using the Confusion assessment method -intensive care unit. Logistic regression and receiver operating characteristics (ROC) curve analysis were used to assess the association between ABI and POD. The mean value of ABI was significantly lower in patients with POD than it was those without POD. Older age, more medical comorbidities, longer length of surgery, decreased ABI, and higher Rutherford class were all significantly associated with POD. The area under ROC (0.74) revealed that ABI below 0.35 was associated with development of POD. Lower preoperative ABI was associated with POD in PAD patients who underwent arterial bypass surgery.

The effects of elective aortic repair, colorectal cancer surgery and subsequent postoperative delirium on long-term quality of life, cognitive functioning and depressive symptoms in older patients

Objectives: This study aimed to demonstrate the impact of elective major abdominal surgery and subsequent postoperative delirium on quality of life (QOL; primary outcome), cognitive functioning and depressive symptoms (secondary outcomes) in older surgical patients.Method: A single-centre, longitudinal prospective cohort study was conducted between November 2015 and June 2018, including patients ≥70 years old who underwent surgery for colorectal cancer or an abdominal aortic aneurysm. They were followed-up at discharge and at 6 and 12 months postoperatively until June 2019. QOL was assessed with the World Health Organization Quality of Life-BREF questionnaire (WHOQOL-BREF). Cognitive functioning was measured with the Mini-Mental State Examination and depressive symptoms with the CES-D 16.Results: In all patients (n = 265), physical and psychological health were significantly lower at discharge compared to baseline (p < 0.001 for both domains). Physical health restored after 6 months, but psychological health remained decreased for the complete study period. Psychological, social and environmental QOL were significantly worse in patients with delirium compared to patients without (p = 0.001, p = 0.006 and p = 0.001 respectively). The cognitive functioning score was significantly lower at baseline in patients with delirium compared to those without (p = 0.006). Patients with delirium had a significantly higher CES-D 16 score compared to those without after 12 months (p = 0.027).Conclusion: Physical and psychological QOL were decreased in the early postoperative period. While physical health was restored after 6 and 12 months, psychological health remained decreased. After 12 months, postoperative delirium resulted in worse psychological, social and environmental QOL and more depressive symptoms. Decreased cognitive functioning may be a risk factor for delirium.

Risk Factors for Delirium after Vascular Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

Vascular surgery is considered a risk factor for the development of postoperative delirium (POD). In this systematic review we provide a report on the incidence and risk-factors of POD after vascular surgery.

METHODS

A systematic literature search was conducted using Pubmed with the MeSH terms and key words "delirium" or "confusion", "vascular surgery procedures" and "risk factors or "risk assessment". Studies were selected for review after meeting the following inclusion criteria: vascular surgery, POD diagnosed using validated screening tools, and DSM-derived criteria to assess delirium. A meta-analysis was performed for each endpoint if at least two studies could be combined.

RESULTS

Sixteen articles met the abovementioned criteria. The incidence of delirium ranged from 5% to 39%. Various preoperative risk factors were identified that is, age (Random MD 3.96, CI 2.57-5.35), hypertension (Fixed OR 1.30, CI 1.05-1.59), diabetes mellitus (Random OR 2.15, CI 1.30-3.56), hearing impairment (Fixed OR 1.89, CI 1.28-2.81), history of cerebrovascular incident or transient ischemic attack (Fixed OR 2.20, CI 1.68-2.88), renal failure (Fixed OR 1.61, CI 1.19-2.17), and pre-operative low haemoglobin level (fixed MD -0.76, CI -1.04 to -0.47). Intra-operative risk factors were duration of surgery (Random MD 15.68; CI 2.79-28.57), open aneurysm repair (Fixed OR 4.99, CI 3.10-8.03), aortic cross clamping time (fixed MD 7.99, CI 2.56-13.42), amputation surgery (random OR 3.77, CI 2.13-6.67), emergency surgery (Fixed OR 4.84, CI 2.81-8.32) and total blood loss (Random MD 496.5, CI 84.51-908.44) and need for blood transfusion (Random OR 3.72, CI 1.57-8.80). Regional anesthesia on the other hand, had a protective effect. Delirium was associated with longer ICU and hospital length of stay, and more frequent discharge to a care facility.

CONCLUSIONS

POD after vascular surgery is a frequent complication and effect-size pooling supports the concept that delirium is a heterogeneous disorder. The risk factors identified can be used to either design a validated risk factor model or individual preventive strategies for high-risk patients.

Which preoperative screening tool should be applied to older patients undergoing elective surgery to predict short-term postoperative outcomes? Lessons from systematic reviews, meta-analyses and guidelines

BACKGROUND

Older surgical patients have a higher risk of postoperative mortality and morbidity compared to younger patients. Timely identification of high-risk patients facilitates comprehensive preoperative evaluation, optimization, and resource allocation to help reduce this risk. This review aims to identify a preoperative screening tool for older patients undergoing elective surgery predictive of poor short-term postoperative outcomes.

METHODS

A scoping review was conducted. An Ovid MEDLINE search was used to identify systematic reviews or meta-analyses comprising older elective patients in at least two different surgical settings. International guidelines were reviewed for recommendations regarding preoperative tools in this population.

RESULTS

Over 50 screening tools were identified. The majority showed a positive association with short-term postoperative mortality and morbidity in older patients. The most commonly described tools were the American Society of Anesthesiologists Physical Status (ASA-PS), frailty tools and domain-specific tools administered as part of comprehensive geriatric assessment (CGA). Due to heterogeneity in outcome measures and statistical methodology the predictive capacity between tools could not be compared. International guidelines described a comprehensive preoperative approach incorporating domain-specific tools rather than recommending a screening tool.

CONCLUSION

Multiple tools were associated with poor short-term postoperative outcomes in older elective surgical patients. No single superior tool could be identified. Frailty, cognitive and/or functional tools were most frequently utilized.

Preoperative prognostic factors associated with postoperative delirium in older people undergoing surgery: protocol for a systematic review and individual patient data meta-analysis

BACKGROUND

Early identification of patients at risk for postoperative delirium is essential because adequate well-timed interventions could reduce the occurrence of delirium and the related detrimental outcomes.

METHODS

We will conduct a systematic review and individual patient data (IPD) meta-analysis of prognostic studies evaluating the predictive value of risk factors associated with an increased risk of postoperative delirium in elderly patients undergoing elective surgery. We will identify eligible studies through systematic search of MEDLINE, EMBASE, and CINAHL from their inception to May 2020. Eligible studies will enroll older adults (≥ 50 years) undergoing elective surgery and assess pre-operative prognostic risk factors for delirium and incidence of delirium measured by a trained individual using a validated delirium assessment tool. Pairs of reviewers will, independently and in duplicate, screen titles and abstracts of identified citations, review the full texts of potentially eligible studies. We will contact chief investigators of eligible studies requesting to share the IPD to a secured repository. We will use one-stage approach for IPD meta-analysis and will assess certainty of evidence using the GRADE approach.

DISCUSSION

Since we are using existing anonymized data, ethical approval is not required for this study. Our results can be used to guide clinical decisions about the most efficient way to prevent postoperative delirium in elderly patients.

SYSTEMATIC REVIEW REGISTRATION

CRD42020171366 .

Preventative effects of ramelteon against postoperative delirium after elective liver resection

Background

Postoperative delirium was reported to be associated with increased postoperative mortality after liver resection. Therefore, it is crucial to prevent postoperative delirium in such cases. Ramelteon, an agonist of melatonin receptor has been suggested to be useful for preventing delirium. The aim of this study was to examine whether ramelteon is effective at preventing delirium after elective liver resection.

Methods

The cases of patients who underwent liver resection at Nara Medical University (Nara, Japan) between January 2014 and August 2018 were analyzed. During the period from January 2017 to August 2018, ramelteon was prospectively administered to patients who underwent liver resection [8 mg/day on the day before surgery and on postoperative days 1 to 3] (ramelteon group), whereas ramelteon was not administered during the period from January 2014 to December 2016 (control group). The perioperative outcomes of the two groups were compared.

Results

There were 120 patients in the ramelteon group and 186 patients in the control group. No significant intergroup differences in background factors, including age, gender, and preoperative serological laboratory data, were detected. The incidence of postoperative delirium was significantly lower in the ramelteon group (5.8% vs. 15.1%, P = 0.035). Multivariate analysis revealed that being aged ≥75 (P = 0.002), being male (P = 0.020), cardiovascular disease (P = 0.023), blood loss ≥1000ml (P = 0.001) and the absence of ramelteon treatment (P = 0.046) were independent risk factors for postoperative delirium.

Conclusion

The administration of ramelteon might reduce the risk of postoperative delirium after elective liver resection.

Risk factors for incident delirium among urological patients: a systematic review and meta-analysis with GRADE summary of findings

Background

Post-operative delirium is an important, yet under-researched complication of surgery. Patients undergoing urological surgery may be at especially high risk of POD, as they are often older, and interventions can be associated with conditions that trigger delirium. The main aim of this systematic review was to evaluate the available evidence for risk factors in this patient group.

Methods

Five databases were searched (MEDLINE, Web of Science, EMBASE, CINAHL and PsychInfo) between January 1987 and June 2019. The Newcastle–Ottawa Scale was used to assess for risk of bias. Pooled odds ratio or mean difference (MD) for individual risk factors were estimated using the Mantel–Haenzel and inverse variance methods.

Results

Seven articles met the inclusion criteria, giving a total population of 1937. The incidence of POD ranged from 5 to 29%. Three studies were deemed low risk of bias and four at a high risk of bias. Nine risk factors were suitable for meta-analysis, with age (MD 4.314 95% CI 1.597, 7.032 p = 0.002) and the clock drawing test (MD − 2.443 95% CI − 3.029, − 1.857 p < 0.001) having a statistically significant association with POD in pooled analyses.

Conclusion

Delirium is common in urological patients. This review has identified a lack of studies in this surgical population, with wide heterogeneity and high risk of bias. It also highlights a number of potential risk factors for post-operative delirium, of which some are modifiable. However, the strength of evidence is weak at present and so future research should focus on assessing comparable risk factors in this patient group in order to inform future clinical practice.

Review registration The review protocol was prospectively registered with the PROSPERO database (reference CRD42017054613)

Risk factors for delirium among older adults in the emergency department: a systematic review protocol

INTRODUCTION

Delirium is commonly missed in older adults presenting to the emergency department (ED). Although current recommendations for active screening of delirium in the ED, this might not be feasible or practical. Identifying patients at high risk for prevalent and incident delirium in the ED will help to improve the screening process and to build interventions. There is currently scattered synthesis of evidence on risk factors associated with delirium in the ED. To address this gap, we are conducting a systematic review to describe the risk factors (patient vulnerability factors and precipitating factors) for delirium in the ED.

METHODS AND ANALYSIS

A literature search was performed from inception to March 2020 in Ovid EBM Reviews, Ovid EMBASE, Ovid MEDLINE, Scopus and Web of Science. We will include original research studies that report a quantitative relationship between at least one risk factor and delirium in the ED setting. Two investigators will use eligibility criteria from this protocol to independently screen titles and abstracts, and select studies based on full-text review of potentially eligible studies. After arriving at a final set of included studies, two investigators will extract data using a standardised data collection form. If appropriate, data regarding each risk factor will be pooled through a random-effect meta-analysis. The Grading of Recommendations Assessment, Development and Evaluation approach will be used to evaluate the overall quality of evidence.

ETHICS AND DISSEMINATION

To our knowledge, this will be the first systematic review evaluating risk factors for prevalent and incident delirium specifically related to the ED setting. Results of this study will aid in the identification of older adults at risk for delirium in the ED. We aim to publish the results of this systematic review in a peer-reviewed journal with good visibility for the fields of emergency medicine and geriatrics.PROSPERO registration numberCDR42020175261.

Cognitive impairment assessment and interventions to optimize surgical patient outcomes

For elderly patients undergoing elective surgical procedures, preoperative evaluation of cognition is often overlooked. Patients may experience postoperative delirium (POD) and postoperative cognitive decline (POCD), especially those with certain risk factors, including advanced age. Preoperative cognitive impairment is a leading risk factor for both POD and POCD, and studies have noted that identifying these deficiencies is critical during the preoperative period so that appropriate preventive strategies can be implemented. Comprehensive geriatric assessment is a useful approach which evaluates a patient's medical, psycho-social, and functional domains objectively. Various screening tools are available for preoperatively identifying patients with cognitive impairment. The Enhanced Recovery After Surgery (ERAS) protocols have been discussed in the context of prehabilitation as an effort to optimize a patient's physical status prior to surgery and decrease the risk of POD and POCD. Evidence-based protocols are warranted to standardize care in efforts to effectively meet the needs of these patients.

The Incidence and Predictors of Postoperative Delirium After Brain Tumor Resection in Adults: A Cross-Sectional Survey

BACKGROUND

Postoperative delirium (POD) describes a multifactorial disease process occurring after surgery. However, few studies have focused on patients undergoing brain tumor resection, and its influencing factors are unclear.

METHODS

We performed a 1-year, single-center, cross-sectional, retrospective survey at Huashan Hospital. Patients were screened using the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU), Confusion Assessment Method, and Richmond Agitation Sedation Scale by trained bedside nurses. Perioperative data were collected using demographic and disease-related questionnaires. The primary outcome measures were the incidence of POD and subtype of POD. Independent predictors of POD were estimated from multivariate logistic regression models, and receiver operating characteristic analysis was used to compare the predictive performance of the models.

RESULTS

Of the 916 patients included in the study, 893 were analyzed. The overall incidence was 14.78%, 67 had hyperactive delirium (50.76%), 55 had hypoactive delirium (41.67%), and 10 had mixed delirium (7.57%). Age, sex, working status, tobacco use history, comorbidities, physical restraint, axillary temperature (>38.5°C), electrolyte disturbances, duration of anesthesia, pathologic diagnosis, tumor site, length of disease, and duration of operation were risk factors for POD. Conversely, saddle area mass was a protective factor. Age, tobacco use history, electrolyte disturbances, physical restraint, and duration of operation were included in the model.

CONCLUSIONS

POD is harmful to patients undergoing brain tumor resection, increasing length of stay in the intensive care unit and hospitalization costs. Intraoperative factors and postoperative factors, in addition to older age and tobacco use history, are associated with POD.

Patient-related and anesthesia-dependent determinants for postoperative delirium after oral and maxillofacial surgery. Results from a register-based case-control study

OBJECTIVE

To identify risk factors for postoperative delirium (POD) after general oral and maxillofacial surgery.

MATERIAL AND METHODS

2420 patients were screened postoperatively for POD using the Nursing Delirium Screening Scale (NuDESC) before discharge from the post anesthesia caring unit (PACU). Basic health data and risk factors were collected. For analysis the study group (n=41) was compared to a control group of 164 randomly selected patients (case-control-ratio=1:4). To identify risk factors for POD multivariable logistic regression models were used. To see whether estimations remain stable, regression analysis was repeated for the subgroup of patients not undergoing dentoalveolar surgery (n=105). To estimate the risk for dentoalveolar surgery a logistic regression model was performed.

RESULTS

Dementia was the only significant risk factor for POD (Odds ratio 41.5; 95% CI 5.48-314), also for patients undergoing other than dentoalveolar surgery (58.1; 1.70-1983). Patients undergoing dentoalveolar surgery were more often suffering from dementia (35.5; 2.85-441), other psychiatric and neurological disorders (3.15; 1.05-9.43), were of younger age (0.97; 0.94-1.00) and had higher anesthesiological risk (3.95; 1.04-14.9).

CONCLUSION

Patients with dementia are at higher risk to develop POD after oral and maxillofacial surgery. We found a strong interdependence between age, dementia, ASA-Score and dentoalveolar surgery.

The pharmacotherapeutic management of postoperative delirium: an expert update

INTRODUCTION

Postoperative delirium is a common sequela in older adults in the peri-operative period leading to poor outcomes with a complex pathophysiology which has led to a variety of different pharmacologic agents employed in attempts to prevent and treat this syndrome. No pharmacologic agent has been approved to treat this disorder, but this review discusses the pharmacologic strategies which have been tried based on the hypotheses of the causation of the syndrome including neurotransmitter imbalance, inflammation, and oxidative stress.

AREAS COVERED

Systematic reviews and meta-analyses of randomized clinical trials (RCTs) were included via search of electronic databases specifically for the terms postoperative delirium and pharmacologic treatments. With this approach, the recurrent topics of analgesia and sedation, antipsychotics, acetylcholinesterase inhibitors (AchE-Is), inflammation, and melatonin were emphasized and provided the outline for this review.

EXPERT OPINION

Research evidence does not support any particular agent in any of the pharmacologic classes reviewed. However, there is some potential benefit with dexmedetomidine, melatonin, and the monitoring of anesthetic agents all of which need further clinical trials to validate these conclusions. Exploration of ways to improve studies and the application of novel pharmacologic agents may offer future benefit.

Risk Factors Associated With Postoperative Delirium in Patients Undergoing Head and Neck Free Flap Reconstruction

Importance

Postoperative delirium (POD) is associated with an increased rate of adverse events, higher health care costs, and longer hospital stays. At present, limited data are available regarding the risk factors for developing POD in patients undergoing head and neck free flap reconstruction. Identification of patients at high risk of developing POD will allow implementation of risk-mitigation strategies.

Objective

To determine the frequency of and risk factors associated with POD in patients undergoing free flap reconstruction secondary to head and neck disease.

Design, Setting, and Participants

This retrospective cohort study included 515 patients undergoing free flap reconstruction from January 1, 2006, through December 31, 2012, at the James Cancer Hospital and Solove Research Institute, The Ohio State University Comprehensive Care Center, a tertiary care cancer hospital. Preoperative, intraoperative, and postoperative data were collected retrospectively. Data from January 1, 2006, through December 31, 2012, were analyzed, and the final date of data analysis was January 8, 2018.

Interventions

Head and neck free flap reconstruction.

Main Outcomes and Measures

The primary outcome was the development of POD as defined by the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition). Univariable and multivariable logistic regression were used to identify risk factors associated with POD.

Results

Five hundred fifteen patients underwent free flap reconstruction during the study period (66.2% male; mean [SD] age, 60.1 [12.8] years). Of these, 56 patients (10.9%) developed POD. On multivariable analysis, risk factors associated with POD included increased age (odds ratio [OR], 1.06; 95% CI, 1.02-1.11), male sex (OR, 5.02; 95% CI, 1.47-17.20), increased operative time (OR for each 1-minute increase, 1.004 [95% CI, 1.001-1.006]; OR for each 1-hour increase, 1.26 [95% CI, 1.08-1.46]), advanced nodal disease (OR, 3.00; 95% CI, 1.39-6.46), and tobacco use (OR, 7.23; 95% CI, 1.43-36.60). Preoperative abstinence from alcohol was identified as a protective factor (OR, 0.24; 95% CI, 0.12-0.51).

Conclusions and Relevance

This study identified variables associated with a higher risk of developing POD. Although many of these risk factors are nonmodifiable, they provide a target population for quality improvement initiatives. Furthermore, preoperative alcohol abstinence may be useful in preventing POD.

Randomized clinical trial of intraoperative dexmedetomidine to prevent delirium in the elderly undergoing major non-cardiac surgery

Background

Delirium is common in elderly patients after surgery and is associated with poor outcomes. This study aimed to investigate the impact of intraoperative dexmedetomidine on the incidence of delirium in elderly patients undergoing major surgery.

Methods

This was a randomized double-blind placebo-controlled trial. Elderly patients (aged 60 years or more) scheduled to undergo major non-cardiac surgery were randomized into two groups. Patients in the intervention group received a loading dose of dexmedetomidine 0·6 μg/kg 10 min before induction of anaesthesia followed by a continuous infusion (0·5 μg per kg per h) until 1 h before the end of surgery. Patients in the control group received volume-matched normal saline in the same schedule. The primary outcome was the incidence of delirium during the first 5 days after surgery. Delirium was assessed with the Confusion Assessment Method (CAM) for non-ventilated patients and CAM for the Intensive Care Unit for ventilated patients.

Results

In total, 309 patients who received dexmedetomidine and 310 control patients were included in the intention-to-treat analysis. The incidence of delirium within 5 days of surgery was lower with dexmedetomidine treatment: 5·5 per cent (17 of 309) versus 10·3 per cent (32 of 310) in the control group (relative risk (RR) 0·53, 95 per cent c.i. 0·30 to 0·94; P = 0·026). The overall incidence of complications at 30 days was also lower after dexmedetomidine (19·4 per cent (60 of 309) versus 26·1 per cent (81 of 310) for controls; RR 0·74, 0·55 to 0·99, P = 0·047).

Conclusion

Intraoperative dexmedetomidine halved the risk of delirium in the elderly after major non-cardiac surgery. Registration number: ChiCTR-IPR-15007654 (www.chictr.org.cn).

Glymphatic System Function in Relation to Anesthesia and Sleep States

The brain is one of the most metabolically active organs in the body. The brain's high energy demand associated with wakefulness persists during rapid eye movement sleep, and even during non-rapid eye movement sleep, cerebral oxygen consumption is only reduced by 20%. The active bioenergetic state parallels metabolic waste production at a higher rate than in other organs, and the lack of lymphatic vasculature in brain parenchyma is therefore a conundrum. A common assumption has been that with a tight blood-brain barrier restricting solute and fluid movements, a lymphatic system is superfluous in the central nervous system. Cerebrospinal fluid (CSF) flow has long been thought to facilitate central nervous system tissue "detoxification" in place of lymphatics. Nonetheless, while CSF production and transport have been studied for decades, the exact processes involved in toxic waste clearance remain poorly understood. Over the past 5 years, emerging data have begun to shed new light on these processes in the form of the "glymphatic system," a novel brain-wide perivascular transit passageway dedicated to CSF transport and metabolic waste drainage from the brain. Here, we review the key anatomical components and operational drivers of the brain's glymphatic system, with a focus on its unique functional dependence on the state of arousal and anesthetic regimens. We also discuss evidence for why clinical exploration of this novel system may in the future provide valuable insight into new strategies for preventing delirium and cognitive dysfunction in perioperative and critical care settings.

Prevention of postoperative delirium in elderly patients planned for elective surgery: systematic review and meta-analysis

Introduction: Vulnerable or “frail” patients are susceptible to the development of delirium when exposed to triggers such as surgical procedures. Once delirium occurs, interventions have little effect on severity or duration, emphasizing the importance of primary prevention. This review provides an overview of interventions to prevent postoperative delirium in elderly patients undergoing elective surgery.

Methods: A literature search was conducted in March 2018. Randomized controlled trials (RCTs) and before-and-after studies on interventions with potential effects on postoperative delirium in elderly surgical patients were included. Acute admission, planned ICU admission, and cardiac patients were excluded. Full texts were reviewed, and quality was assessed by two independent reviewers. Primary outcome was the incidence of delirium. Secondary outcomes were severity and duration of delirium. Pooled risk ratios (RRs) were calculated for incidences of delirium where similar intervention techniques were used.

Results: Thirty-one RCTs and four before-and-after studies were included for analysis. In 19 studies, intervention decreased the incidences of postoperative delirium. Severity was reduced in three out of nine studies which reported severity of delirium. Duration was reduced in three out of six studies. Pooled analysis showed a significant reduction in delirium incidence for dexmedetomidine treatment, and bispectral index (BIS)-guided anaesthesia. Based on sensitivity analyses, by leaving out studies with a high risk of bias, multicomponent interventions and antipsychotics can also significantly reduce the incidence of delirium.

Conclusion: Multicomponent interventions, the use of antipsychotics, BIS-guidance, and dexmedetomidine treatment can successfully reduce the incidence of postoperative delirium in elderly patients undergoing elective, non-cardiac surgery. However, present studies are heterogeneous, and high-quality studies are scarce. Future studies should add these preventive methods to already existing multimodal and multidisciplinary interventions to tackle as many precipitating factors as possible, starting in the pre-admission period.

Multimodal prehabilitation to reduce the incidence of delirium and other adverse events in elderly patients undergoing elective major abdominal surgery: An uncontrolled before-and-after study

Background

Delirium is a common and serious complication in elderly patients undergoing major abdominal surgery, with significant adverse outcomes. Successful strategies or therapies to reduce the incidence of delirium are scarce. The objective of this study was to assess the role of prehabilitation in reducing the incidence of delirium in elderly patients.

Methods

A single-center uncontrolled before-and-after study was conducted, including patients aged 70 years or older who underwent elective abdominal surgery for colorectal carcinoma or an abdominal aortic aneurysm between January 2013 and October 2015 (control group) and between November 2015 and June 2018 (prehabilitation group). The prehabilitation group received interventions to improve patients’ physical health, nutritional status, factors of frailty and preoperative anaemia prior to surgery. The primary outcome was incidence of delirium, diagnosed with the DSM-V criteria or the confusion assessment method. Secondary outcomes were additional complications, length of stay, unplanned ICU admission, length of ICU stay, readmission rate, institutionalization, and in-hospital or 30-day mortality.

Result

A total of 360 control patients and 267 prehabilitation patients were included in the final analysis. The mean number of prehabilitation days was 39 days. The prehabilitation group had a higher burden of comorbidities and was more physically and visually impaired at baseline. At adjusted logistic regression analysis, delirium incidence was reduced significantly from 11.7 to 8.2% (OR 0.56; 95% CI 0.32–0.98; P = 0.043). No statistically significant effects were seen on secondary outcomes.

Conclusion

Current prehabilitation program is feasible and safe, and can reduce delirium incidence in elderly patients undergoing elective major abdominal surgery. This program merits further evaluation.

Trial registration

Dutch Trial Registration, NTR5932.