Preoperative inflammatory mediators and postoperative delirium: systematic review and meta-analysis

Prediction of postoperative delirium by blood metabolome analysis

No established blood markers can preoperatively predict postoperative delirium. Blood concentrations of amino acid catabolites and dipeptides, including those secreted extracellularly during T-lymphocyte activation, were investigated as predictors of postoperative delirium using metabolomic analyses to ascertain whether preoperative blood metabolites could predict postoperative delirium. Eighteen and 24 participants were included in the delirium and non-delirium groups, respectively. Higher preoperative levels of amino acid (tryptophan) catabolites, via the indoleamine 2,3-dioxygenase pathway, were observed in the delirium group and identified as potential predictors of postoperative delirium in this study. The delirium group had preoperatively elevated levels of tryptophan catabolites and only a limited increase postoperatively, suggesting that the tryptophan catabolic pathway may be activated preoperatively in patients at high risk of delirium. Non-targeted metabolomic analysis found a set of preoperatively elevated γ-glutamyl dipeptides as potential predictors of postoperative delirium. In vitro experiments showed that T-cell-receptor stimulation increases tryptophan metabolism and specific γ-glutamyl dipeptide secretion, offering a possible explanation for the increased levels of metabolites in postoperative delirium. This study showed that levels of amino acid metabolites associated with blood immune activity may have the potential to predict postoperative delirium.

Hemoglobin to red cell distribution width ratio predicts postoperative delirium in older patients undergoing hip fracture surgery: A retrospective cohort study

AIM

This study aimed to investigate the predictive effect of hemoglobin to red cell distribution width ratio (HRR) on postoperative delirium (POD) in older patients undergoing hip fracture surgery.

METHODS

POD was diagnosed by capturing descriptive words from the medical records. The correlation between POD and HRR was determined using logistic regression analysis, and the receiver operating characteristic curve was used to further evaluate the value of HRR in predicting POD.

RESULTS

In total, 202 older patients accepting hip fracture surgery were included in our study. The result of multiple logistic regression analysis presented HRR (odds ratio, 0.504 [95% confidence interval, 0.340-0.747]; P < 0.001), American Society of Anesthesiologists physical status >2, and neutrophils were independently correlated with POD. The area under the curve of HRR was 0.746 (95% confidence interval, 0.676-0.815), and the optimal cutoff value was 8.322.

CONCLUSIONS

HRR, American Society of Anesthesiologists physical status >2 and neutrophils could independently predict POD in older patients undergoing hip fracture surgery, and HRR had satisfactory predictive value. However, further research is needed to confirm our findings. Geriatr Gerontol Int 2025; 25: 565-571.

Effect of parecoxib on postoperative delirium in patients with hyperlipidemia: a randomized, double-blind, single-center, superiority trial

BACKGROUND

Hyperlipidemia has been implicated in the higher risk of developing postoperative delirium. Prostaglandin endoperoxide synthase-2 mediates neuroinflammatory processes in postoperative delirium. This study aims to investigate whether preoperative administration of parecoxib is more efficient than a placebo in averting postoperative delirium in patients with hyperlipidemia.

MATERIALS AND METHODS

In this randomized, double-blind, superiority trial, participants with hyperlipidemia were randomized in a 1:1 ratio to receive parecoxib (40 mg parecoxib administered intravenously before anesthesia induction) or placebo (normal saline). The primary outcome was postoperative delirium incidence within three days, with a 5.4% difference set as the superiority threshold. Secondary outcomes were cumulative incidences of emergence delirium and prostaglandin endoperoxide synthase-2 levels, inflammatory cell counts, and pain score on postoperative day 1 and postoperative adverse events.

RESULTS

This trial conducted between August 2023 and August 2024 at a tertiary hospital in China included 452 adults with hyperlipidemia, with 226 in the parecoxib group and 226 in the placebo group. The incidence of postoperative delirium in the parecoxib group was 13.72%, a reduction of 12.39% compared to the placebo group (hazard ratio, 0.491; 95% confidence interval: 0.318 to 0.759; P < 0.001). The parecoxib group also had a lower incidence of emergence delirium, prostaglandin endoperoxide synthase-2 levels, white blood cell counts and neutrophil, and pain scores on postoperative day 1. The occurrence of adverse events was comparable between the two groups. Prostaglandin endoperoxide synthase-2 expression levels, white blood cell counts, and pain scores mediated the reduction of postoperative delirium incidence by parecoxib.

CONCLUSION

Parecoxib may help in reducing the hyperlipidemia-related postoperative delirium incidence. The effective anti-inflammatory activity of prostaglandin endoperoxide synthase-2 inhibition by parecoxib and postoperative pain control may be important mechanisms for preventing postoperative delirium.

The relationship between preoperative serum indirect bilirubin and postoperative delirium in geriatric patients undergoing joint replacement

BACKGROUND

Postoperative delirium (POD) is one of the most common complications in geriatric patients following surgery. Physiological concentration of bilirubin possesses anti-inflammatory, antioxidant and neuroprotective effects, which are important protective mechanisms against POD. This study aimed to explore the relationship between preoperative serum bilirubin and POD in geriatric patients undergoing joint replacement.

METHODS

Geriatric patients who underwent hip or knee joint replacement surgery under intrathecal anesthesia were included. These patients had American Society of Anesthesiologists (ASA) grades I to III. The patients with a history of psychiatric or neurological disorders, infectious diseases or sepsis, hemolytic anemia, liver diseases, performed general anesthesia or intrathecal anesthesia combined with general anesthesia, or insufficient surgical information were excluded. Patients' age, gender, weight, height, ASA classification, liver function and bilirubin within one week before surgery, preoperative Mini-Mental State Examination (MMSE) scores, surgical type, dosage of medications, intraoperative bleeding volume, postoperative average numeric rating scale (NRS) pain scores, the occurrence of POD and Delirium Rating Scale-Revised-98 (DRS-R-98) scores for POD were collected.

RESULTS

A total of 269 patients were eligible for inclusion in the study, with 23.05% (62/207) exhibiting POD. Patients with POD exhibited higher age and ASA classification, and had lower weight, serum total serum bilirubin (TBIL) and indirect bilirubin (IBIL) within one week before surgery, and preoperative MMSE scores (all p < 0.05). Univariate logistic regression analysis showed that the above variables were correlated with the occurrence of POD (all p < 0.05). Multivariate logistic regression analysis revealed that age was a risk factor (p < 0.001, OR = 1.14, 95% CI [1.07-1.21]), while weight (p = 0.041, OR = 0.96, 95% CI [0.92-0.99]), IBIL levels within one week before surgery (p = 0.012, OR = 0.65, 95% CI [0.47-0.91]) and preoperative MMSE scores (p < 0.001, OR = 0.84, 95% CI [0.78-0.91]) served as protective factors against the occurrence of POD. The serum IBIL concentration within one week before surgery was performed receiver operating characteristic (ROC) curve analysis. The estimated cutoff value for predicting the occurrence of POD was 6.65 μmol/L, and area under the curve (AUC) was 0.63. Patients with preoperative serum IBIL concentration below 6.65 μmol/L had a higher incidence of POD.

CONCLUSION

Patients with lower preoperative serum IBIL levels exhibited a higher incidence of POD in geriatric patients undergoing joint replacement. Low serum IBIL was a risk factor and a predictor for the occurrence of POD.

Relationship between preoperative high arterial blood lactate level and delirium after deep brain stimulation surgery in Parkinson's disease

Introduction: We performed the retrospective study to investigate the relationship between preoperative arterial blood lactate level and postoperative delirium (POD) in Parkinson's disease (PD) patients undergoing deep brain stimulation (DBS) surgery. Methods: Perioperative data of patients undergoing DBS surgery under total intravenous anesthesia were collected in the study. In addition, mini-mental state exam score for assessing cognitive function and confusion assessment method for assessing perioperative delirium in the PD patients were collected. The relationship between preoperative lactate level and POD was analyzed using binary logistic regression analysis. Results: A total of 156 patients were included, of whom 29 (17.6%) patients developed POD. Multivariable logistic regression analysis showed that preoperative lactate level was independently associated with POD regarding of continuous variable [odds ratio (OR) = 12.46, 95% confidence interval (CI)=3.12-49.71, P<0.001] or categorical variable (OR= 3.58, 95% CI =1.20-10.65, P=0.022 for lactate≥1.41). Receiver operating characteristic curve analysis showed that preoperative arterial blood lactate level was a significant predictive biomarker for POD, with an area under the curve of 0.708(95%CI=0.606-0.809, P<0.05). Subgroup analysis indicated that high preoperative lactate levels were an independent risk factor for delirium after DBS surgery (OR=10.71,95%CI=1.17-97.87, P=0.036) in female Parkinson's disease patients. Discussion: Preoperative high level of lactate is an independent factor for delirium after DBS surgery in patients with Parkinson's disease.

Preoperative quantitative quadriceps muscle ultrasound to predict POD for gastrointestinal surgery in older patients

OBJECTIVE

Postoperative delirium (POD) is generally associated with increased postoperative adverse events. We aimed to investigate whether preoperative quantitative quadriceps muscle ultrasound could predict POD in older patients after gastrointestinal surgery in order to provide more targeted prevention and treatment measures.

METHODS

We prospectively collected data from elderly patients who underwent elective gastrointestinal surgery from August to December 2023 at a tertiary hospital in China. Intergroup difference analysis and univariate and multivariate logistic regression analyses were used to explore independent risk factors. We calculated and assessed the parameters via sensitivity, specificity, the Youden index, and the area under the receiver operating characteristic curve (AUC), calibration curves and the Hosmer-Lemeshow test. The nomogram was validated internally through bootstrap resampling. The decision curve analysis (DCA) was used to evaluate its clinical validity.

RESULTS

A total of 695 patients who underwent gastrointestinal surgery were analyzed in this investigation, among which 137 patients experienced POD with an incidence rate of 19.7%. After conducting multivariate logistic regression analyses using R software, six independent risk factors associated with POD were identified, including age, quadriceps muscle thickness (Q-MT), quadriceps echo intensity (Q-EI), Charlson Comorbidity Index (CCI), preoperative frailty and preoperative Minimum Mental State Examination (MMSE) scores. The AUC value of the model was 0.966 (95% CI: 0.950-0.982; p < 0.05). The calibration curve revealed that the predicted probability of the nomogram was consistent with the actual probability, and the Hosmer-Lemeshow goodness-of-fit test value was 0.811. DCA revealed that the nomogram has a net benefit for POD.

CONCLUSION

Quantitative quadriceps ultrasound parameters, including the Q-MT and Q-EI, could predict POD after gastrointestinal surgery in older patients. We have developed a new nomogram for predicting POD in older patients who undergo gastrointestinal surgery.

STUDY REGISTRATION

The trial was registered in the Chinese Clinical Trial Registry ( http://www.chictr.org.cn/ ) on August 3, 2023, with the registration number of ChiCTR2300074304.

Cytokines and inflammatory biomarkers and their association with post-operative delirium: a meta-analysis and systematic review

Delirium is a prevalent cognitive disorder among older patients and a common phenomenon following major surgical procedures. This study aimed to identify the significant proteomic biomarkers and examine their association with postoperative delirium (POD). Four electronic databases were used to identify the published articles between 1st January 2000 and 31st December 2023. Among the included 40 studies, the meta-analysis investigated 13 potential cytokines and inflammatory biomarker proteins linked with postoperative delirium. The Hedge's g standardized mean difference (SMD) was applied to calculate the effect size, with 95% confidence intervals (CIs), under the fixed effect or random effect model based on the heterogeneity index of I2. Patients with POD exhibited significantly higher elevated levels of inflammatory biomarkers IL-6 (SMD = 1.45), CRP (SMD = 1.26), GFAP (SMD = 1.15), IL-1B (SMD = 0.95), IL-10 (SMD = 0.57), IL-8 (SMD = 0.56), MCP-1 (SMD = 0.39), and NFL (SMD = 0.44), suggesting that these proteins may play an inevitable role in delirium-associated cytokines and inflammatory response, development and progression of delirium. Conversely, a reduction in IGF-1 protein level (SMD =  - 0.24) was also significantly associated with POD, suggesting a potential vulnerability to delirium. This study paves the way for future research aimed at early diagnosis, personalized treatment, and the development of novel therapeutic strategies to manage delirium effectively.

Patients' and family members' dyadic experience of post-operative delirium in the intensive care unit: A qualitative study

BACKGROUND

Post-operative delirium is a complication with long-lasting consequences for both patients and their families. This is particularly true for those transferred to the intensive care unit after surgery, where the incidence of post-operative delirium is high, and patient outcomes are often poor. Despite the acknowledged role of family engagement in delirium management, previous research has mainly focused on patients, with limited exploration of the shared experiences between patients and family members.

AIM

This study aims to explore the experiences of patients and family members during episodes of post-operative delirium in the intensive care unit to better understand their unmet needs.

STUDY DESIGN

A qualitative descriptive study was conducted at a tertiary general hospital. Eighteen pairs of patients, their family members and two other family members were interviewed. Data were collected through face-to-face semi-structured interviews within the first week after patients' discharge from the intensive care unit and analysed using thematic analysis.

RESULTS

Four major themes emerged: (1) the dyadic relationship between patients and family members must be understood in the context of their shared emotional and behavioural experiences; (2) family's history may predispose patients to post-operative delirium; (3) family engagement may prevent the development of post-operative delirium; and (4) inadequate communication between health care providers and patients or families may negatively affect post-operative delirium outcomes.

CONCLUSIONS

Post-operative delirium presents significant emotional and physical challenges for both patients and their families. Addressing these challenges requires improved communication between health care providers and families, as well as strategies that emphasize early family support and collaboration in care.

RELEVANCE TO CLINICAL PRACTICE

Patients and their families should be considered a unit during post-operative delirium management, and earlier family engagement is essential. Health care systems should adapt intensive care unit practices to meet the dynamic needs of families, promoting more comprehensive support during critical care.

Deep Hypothermic Low Flow Results in Multiple Aspects of Neurological Deficits in Mice by eEF2 Hyperphosphorylation

Postoperative neurological dysfunction is a common complication caused by deep hypothermia with cerebral hypoperfusion during aortic arch surgery, but the exact pathological changes and molecular mechanisms are not yet clear. In this study, we established an adult mouse model of deep hypothermic low flow (DHLF) to simulate the ischemic-reperfusion brain injury during aortic arch surgery. The DHLF-modeled mice showed significant neurological and cognitive dysfunction, accompanied by reduced dendritic spine density and increased glial cell activation in the hippocampus and cortex. DHLF induced proteomic changes primarily involved in synaptic organization in the hippocampus and cortex, with AMPA and NMDA receptor subunits and synaptic activity-dependent proteins markedly downregulated in the hippocampus and/or cortex. Moreover, DHLF also resulted in altered proteome in mRNA translation and inhibition of eukaryotic elongation factor 2 (eEF2), a crucial regulator of translational elongation whose activity is negatively regulated via phosphorylation by eEF2 kinase (eEF2K). Importantly, the administration of the small-molecular eEF2K inhibitor A484954 ameliorated DHLF-induced neurobehavioral dysfunction, dendritic spine reduction, and glial cell activation, suggesting that eEF2K/eEF2 may be a promising therapeutic target in DHLF-induced neurological injury. Our findings revealed new evidence of pathological features, molecular mechanism, and intervention of DHLF-induced cerebral ischemia-reperfusion injury, providing promising insight for developing strategies on reducing postoperative neurological complications after aortic arch surgery.

The impact of preoperative psychiatric intervention for postoperative delirium after major oral and maxillofacial surgery with free flap reconstruction

BACKGROUND

Postoperative delirium (POD) is a severe complication associated with various adverse outcomes, especially in older patients. Although the incidence and risk factors for POD have been explored in general surgery, they have not been fully elucidated. Early identification of high-risk patients and active preoperative intervention are considered essential for the prevention of POD. Recently, psychiatric consultation intervention have been shown to prevent delirium. This study investigated the effect of preoperative psychiatric interventions on preventing POD in our specific surgical context.

MATERIALS AND METHODS

This retrospective, single-center observational study included 86 patients who underwent major oral and maxillofacial surgery with free flap reconstruction between 2016 and 2023. The effect of psychiatric intervention were compared between patients with and without delirium.

RESULTS

Preoperative psychiatric intervention did not reduce the incidence of POD. The incidence of POD was 29.1 %. Univariate analyses showed no significant associations between POD and any clinical variables.

CONCLUSION

There was no difference in the incidence of POD between patients who received preoperative psychiatric intervention and those who did not, and further investigation is needed to determine the efficacy of preoperative psychiatric intervention in the prevention of POD.

Proposing Bromo-epi-androsterone (BEA) for perioperative neurocognitive disorders with Interleukin-6 as a druggable target

Cognitive impairment following surgery is a significant complication, affecting multiple neurocognitive domains. The term "perioperative neurocognitive disorders" (PND) is recommended to encompass this entity. Individuals who develop PND are typically older and have increases in serum and brain pro-inflammatory cytokines notwithstanding the type of surgery undergone. Surgical trauma induces production of small biomolecules, damage-associated molecular patterns (DAMP), particularly the DAMP known as high molecular group box 1 protein (HMGB1). Mechanistically, peripheral surgical trauma promotes pro-inflammatory cytokines that stimulate central nervous system (CNS) inflammation by disrupting the blood-brain barrier (BBB) causing functional neuronal disruption that leads to PND. PND is strongly linked to elevations in serum and CNS pro-inflammatory cytokines interleukin-1 beta (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor alpha (TNFα); these cytokines cause further release of HMGB1 creating a positive feedback loop that amplifies the inflammatory response. The cytokine IL-6 is necessary and sufficient for PND. Dehydroepiandrosterone (DHEA) is a principal component of the steroid metabolome and is involved in immune homeostasis. DHEA has been shown to suppress expression of several pro-inflammatory cytokines by regulation of the NF-kB pathway. Bromo-epi-androsterone (BEA) is a potent synthetic analog of DHEA; unlike DHEA, it is non-androgenic, non-anabolic and is an effective modulator of immune dysregulation. In a randomized, placebo-controlled clinical trial, BEA effected significant and sustained decreases in IL-1β, TNFα and IL-6. This article presents BEA as a potential candidate for clinical trials targeting PND and further suggests the use of BEA in elective total hip arthroplasty as a well-documented surgical entity relevant to the management of PND.

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.

Complete Blood Cell Count-Based Ratios Identify Total Joint Arthroplasty Patients Likely to Benefit from Perioperative Dexamethasone

BACKGROUND

Complete blood cell count-based ratios (CBRs), including the neutrophil-lymphocyte ratio (NLR) and monocyte-lymphocyte ratio (MLR), are inflammatory markers associated with postoperative morbidity. Given the link between the surgical stress response and complications after total joint arthroplasty (TJA), this study aimed to evaluate whether higher preoperative CBR values predict greater postoperative benefits associated with dexamethasone utilization.

METHODS

The Premier Healthcare Database was queried for adult patients who underwent primary, elective total hip or knee arthroplasty (THA or TKA). Multivariable logistic regression models using dexamethasone exposure and CBRs as independent variables assessed primary end points of 90-day postoperative complications and length of stay (LOS) of ≥3 days. The probability difference between the dexamethasone and non-dexamethasone groups for each primary end point was determined across all values of each CBR. Probability differences were compared across CBR quartiles.

RESULTS

A total of 32,849 primary, elective TJAs (12,788 THAs [38.93%], 20,061 TKAs [61.07%]) performed between 2016 and 2021 were identified, and 22,282 (67.83%) of the patients received perioperative dexamethasone. Among patients with an NLR value of >1.00, those receiving dexamethasone had a lower probability of postoperative complications (all p < 0.05). Dexamethasone was associated with lower odds of an LOS of ≥3 days among patients in the highest NLR quartile (≥4.67) compared with the lowest quartile (NLR <1.84) (p = 0.002). Among patients with an MLR value of ≥0.36, those receiving dexamethasone had significantly lower odds of postoperative complications. Dexamethasone was associated with lower odds of an LOS of ≥3 days among patients with an MLR of ≥0.33 (the 2 highest quartiles) compared with an MLR of <0.24 (the lowest quartile) (p = 0.039).

CONCLUSIONS

Higher NLR and MLR values were associated with greater marginal benefit from perioperative dexamethasone treatment, establishing a modifiable link between adverse outcomes and perioperative inflammation in TJA.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

The role of C-reactive protein as a risk marker of postoperative delirium in older hip fracture patients: a prospective cohort study

PURPOSE

Postoperative delirium (POD) is a common and serious neuropsychiatric syndrome that leads to higher morbidity and mortality. We investigated the association between serum C-reactive protein (CRP) and the occurrence of POD in older hip fracture patients, and whether CRP predicted POD better than a clinical model.

METHODS

Patients aged ≥ 75 years admitted for surgical repair of an acute hip fracture were recruited. We compared serum CRP levels between patients with and without POD.

RESULTS

Sixty patients were included, of whom 21 (35%) developed POD. Serum CRP levels were significantly higher in patients who developed delirium (p = 0.011). In a multiple regression model including clinical variables and CRP, cognitive impairment (p = 0.003) and infection (p = 0.001) were the best predictors of POD.

CONCLUSIONS

Although higher levels of serum CRP were significantly associated with POD in older hip fracture patients, pre-existing cognitive impairment and infections were the most important risk factors for POD.

Frailty as a mediator of postoperative delirium in older adults undergoing orthopedic surgery: A causal mediation analysis

Background

Postoperative delirium has a high prevalence in hospitalized older adults. Frail older adults have an increased risk for developing it. Preoperative pain-a common symptom in older adults with orthopedic conditions-shows a connection with frailty through an inflammatory process. However, an association among preoperative pain, frailty, and postoperative delirium remains unexplored among older adults undergoing orthopedic surgery.

Objectives

To examine the magnitude, direction, and mediation effect of frailty on the association between preoperative pain and postoperative delirium among older adults undergoing orthopedic surgery.

Design

A secondary analysis of a prospective cohort study.

Setting and participants

A cohort of 200 older adults (60 years and older) who underwent major orthopedic surgery at a university hospital in Thailand was recruited for the study.

Methods

Participants responded to the Demographic and Health Information Form, the Reported Edmonton Frailty Scale-Thai version, and the Thai version of the 4 A's test. Analyses were conducted using a causal mediation analysis with 95 % confidence intervals.

Results

We found that 12.5 % of participants developed postoperative delirium. For the direct paths associated with postoperative delirium, statistically significant effects were observed for frailty, preoperative pain, and comorbidity. Considering frailty as a mediator of postoperative delirium, a significant positive indirect effect was identified from preoperative pain. Controlling for age and comorbidities, frailty mediated the association between preoperative pain and postoperative delirium in a statistically significant manner; the average direct effect was 0.014 (95 % confidence interval: 0.008-0.020), the average causal mediating effect was 0.002 (95 % confidence interval: 0.000-0.010), the total effects was 0.017 (95 % confidence interval: 0.010-0.020), and the probability mediation accounted for 14 % (95 % confidence interval: 0.031-0.300).

Conclusion

Integrating the concept of age-related decline and frailty assessment may offer opportunities to provide disease-specific care and strengthen precision perioperative care, which ultimately enhance quality of life in older adults undergoing orthopedic surgery.

Systemic immune inflammatory index (SII) and systemic inflammatory response index (SIRI) as predictors of postoperative delirium in patients undergoing off-pump coronary artery bypass grafting (OPCABG) with cerebral infarction

OBJECTIVE

Postoperative delirium (POD) is a common complication following off-pump coronary artery bypass grafting (OPCABG) and is associated with significant morbidity. This study aims to evaluate the correlation of systemic immune inflammatory index (SII) and systemic inflammatory response index (SIRI) with postoperative delirium (POD) in patients with cerebral infarction undergoing OPCABG.

METHODS

The perioperative cohort study included 321 patients who underwent OPCABG. Patients were divided into two groups based on the occurrence of POD: the delirium group (n = 113) and the non-delirium group (n = 208). Baseline characteristics, including gender, left ventricular ejection fraction (LVEF), surgery duration, hypertension, age, and smoking history were analyzed. SII and SIRI values were calculated preoperatively, and their association with POD was assessed using univariate and multivariate logistic regression analyses. Receiver operating characteristic (ROC) curves were used to evaluate the predictive accuracy of SII and SIRI.

RESULTS

Statistical differences between SII and SIRI in the two groups (P < 0.05) were observed. Multivariate analysis confirmed that SII and SIRI, age and preoperative smoking history were predictors of POD. ROC curve analysis demonstrated that SII and SIRI had considerable predictive power, with AUC values of 0.73 (0.67-0.79) for SII and 0.75 (0.69-0.81) for SIRI.

CONCLUSION

SII and SIRI were found to be associated with an increased risk of POD in patients undergoing OPCABG, but further research is needed to confirm these findings and determine their independence as risk factors.

A Novel Nomogram Developed Based on Preoperative Immune Inflammation-Related Indicators for the Prediction of Postoperative Delirium Risk in Elderly Hip Fracture Cases: A Single-Center Retrospective Cohort Study

Objective

Postoperative delirium (POD) commonly occurs in elderly individuals following hip fracture surgery, with unclear pathophysiological mechanism. Inflammation is a known factor affecting the onset of delirium. The current work aimed to examine the associations of preoperative immune inflammation-related indicators with POD occurrence in elderly cases following hip fracture surgery.

Methods

The current retrospective cohort study included 437 elderly cases administered hip fracture surgery from January 2018 to December 2023. The clinicodemographic data and laboratory findings of all cases were retrospectively analyzed. Immune inflammation-related indicators were assessed, eg, MLR, NLR and PLR, as well as SII and SIRI. The bootstrap method was employed to assign cases at 7:3 to the training (48 and 258 cases in the POD and no-POD groups, respectively) and internal validation (13 and 118 cases in the POD and no-POD groups, respectively) cohorts. Next, LASSO, univariable and multivariable logistic regression analyses were applied to determine risk factors in the training cohort, based on which a nomogram model was built. The obtained nomogram was examined for accuracy by calibration plot analysis. Finally, the nomogram's clinical value was assessed by decision curve analysis (DCA), followed by internal validation based on the training cohort.

Results

Of all 437 cases, 61 developed POD, indicating a POD incidence of 13.96%. LASSO regression and multivariable analyses revealed preoperative SIRI independently predicted POD in the training cohort. The developed nomogram had an area under the curve (AUC) of 0.991 (95% CI 0.983~0.998) in the training cohort versus 0.986 (95% CI 0.966~1.000) in the validation cohort. Calibration curve analysis revealed nomogram-predicted and actual probabilities were in line. DCA demonstrated the novel nomogram could confer net benefits for POD prediction in elderly cases administered hip fracture surgery.

Conclusion

The immune inflammation-related indicators SIRI could predict POD in elderly cases following hip fracture surgery.

Nutritional Status and Inflammation as Mediators of Physical Performance and Delirium in Elderly Community-Acquired Pneumonia Patients: A Retrospective Cohort Study

Purpose

This study proposes a multiple mediation model to evaluate the association among diminished physical performance, malnutrition, inflammation, and delirium in seniors with community-acquired pneumonia.

Patients and Methods

This retrospective cohort study included elderly patients hospitalized for community-acquired pneumonia at the Geriatrics Department of the Second People's Hospital of Lianyungang from January 1, 2020, to January 1, 2024. Logistic regression analysis was conducted to examine the associations among physical performance, nutritional status, C-reactive protein (CRP) levels, and delirium. Mediation models assessed the effects of nutritional status and CRP on the relationship between physical performance and delirium, with subgroup analyses based on diabetes status.

Results

A total of 379 patients were included, with a mean age of 80.0±7.4 years, and 51.7% were male. The incidence of delirium during hospitalization was 28.5% (n=108). Subgroup analyses revealed significant correlations between physical performance, nutritional status, and CRP (P<0.001), regardless of diabetes status. After adjusting for confounding variables, CRP was positively associated with delirium, while MNA-SF and SPPB scores showed negative correlations with delirium risk (OR=0.852, 95% CI: 0.730-0.995; OR=0.580, 95% CI: 0.464-0.727, P<0.05). Mediation analyses indicated that MNA-SF scores and CRP significantly mediated the association between SPPB and delirium. Specifically, pathways "SPPB→ MNA-SF→ delirium", "SPPB→ CRP→ delirium", and "SPPB→ MNA-SF→ CRP→ delirium" demonstrated significant mediating effects in patients without diabetes, while only the pathway "SPPB→ MNA-SF→ CRP→ delirium" was significant in those with diabetes.

Conclusion

Older patients with community-acquired pneumonia and poor physical performance are more susceptible to delirium, with nutritional status and inflammation as key mediators.

Decreased DTI-ALPS index in delirium: a preliminary MRI study

PURPOSE

Delirium is linked to brain abnormalities, yet the role of the glymphatic system is not well understood. This study aims to examine alterations in brain physiology in delirium by using diffusion-tensor imaging (DTI) to assess water diffusion along the perivascular space (ALPS) and to explore its correlation with clinical symptoms.

METHODS

We examined 15 patients with delirium and 15 healthy controls, measuring water diffusion metrics along the x-, y-, and z-axes in both projection and association fibers to determine the DTI-ALPS index. We used a general linear model, adjusted for age and sex, to compare the DTI-ALPS index between groups. We also investigated the relationship between the DTI-ALPS index and clinical symptoms using partial correlations.

RESULTS

Patients with delirium exhibited significantly lower DTI-ALPS indices compared to healthy controls (1.25 ± 0.15 vs. 1.38 ± 0.10, t = 2.903, p = 0.007; 1.27 ± 0.16 vs. 1.39 ± 0.08, 1.22 ± 0.16 vs. 1.37 ± 0.14, t = 2.617, p = 0.014; t = 2.719, p = 0.011; respectively). However, there was no significant correlation between the DTI-ALPS index and clinical symptoms.

CONCLUSION

Our findings indicate a decreased DTI-ALPS index in patients with delirium, suggesting potential alterations in brain physiology that may contribute to the pathophysiology of delirium. This study provides new insights into the mechanisms underlying delirium.

The effect of non-steroidal anti-inflammatory drugs on postoperative delirium: a meta-analysis

BACKGROUND

Neuroinflammation is postulated as a potential mechanism underlying postoperative delirium. This study aimed to investigate the impact of non-steroidal anti-inflammatory drug (NSAID) use on postoperative delirium.

METHODS

We conducted a literature search in electronic databases, including PubMed, EMBASE, CENTRAL, and Web of Science, to identify eligible randomized controlled studies. The primary outcome was the incidence of postoperative delirium, and the secondary outcomes included pain scores and the amounts of opioid used at 24 h postoperatively. We estimated the effect size through calculating the odds ratios (ORs) or mean differences (MDs) with 95% CIs, as appropriate.

RESULTS

In the analysis of eight studies involving 1,238 participants, the incidence of postoperative delirium was 11% and 19% in the NSAID and control groups, respectively, with a significant reduction in the NSAID group (OR: 0.54, 95% CI [0.38, 0.7], P = 0.0001, I2 = 0%). NSAID use had a significant effect on postoperative pain reduction (MD: -0.75, 95% CI [-1.37, -0.13], P = 0.0172, I2 = 88%). Significant lower postoperative opioid consumption was observed in the NSAID group (MD: -2.88, 95% CI [-3.54, -2.22], P = 0.0000; I2 = 0%).

CONCLUSIONS

NSAID administration reduced the incidence of postoperative delirium, severity of pain, and opioid dose used.

Up-regulating GABA transporter-3 in the zona incerta prevents surgery-induced memory impairment in mice

Clinical surgery can lead to severe neuroinflammation and cognitive dysfunctions. It has been reported that astrocytes mediate memory formation and postoperative cognitive dysfunction (POCD), however, the thalamic mechanism of astrocytes in mediating POCD remains unknown. Here, we report that reactive astrocytes in zona incerta (ZI) mediate surgery-induced recognition memory impairment in male mice. Immunostaining results showed that astrocytes are activated with GABA transporter-3 (GAT-3) being down-expressed, and neurons were suppressed in the ZI. Besides, our work revealed that reactive astrocytes caused increased tonic current in ZI neurons. Up-regulating the expression of GAT-3 in astrocytes ameliorates surgery-induced recognition memory impairment. Together, our work demonstrates that the reactive astrocytes in the ZI play a crucial role in surgery-induced memory impairment, which provides a new target for the treatment of surgery-induced neural dysfunctions.

Association of preoperative neutrophil-to-lymphocyte ratio with the risk of postoperative delirium in elderly patients undergoing noncardiac surgery: a systematic review and meta-analysis

To assess the correlation between preoperative neutrophil-to-lymphocyte ratio (NLR) and risk of postoperative delirium (POD) in older patients undergoing noncardiac surgery. PubMed, Web of Science, Embase, and Scopus were systematically retrieved from inception until February 2023. Two authors independently conducted the selection of literature, data extraction and statistical analysis. In this meta-analysis, Review Manager 5.4 was used for statistical analysis, and the mean difference (MD) and 95% confidence intervals (CIs) of preoperative NLR between the POD group and non-POD group were calculated. We utilised the Newcastle-Ottawa Scale (NOS) to evaluate the quality of literature. Further, our meta-analysis used a random-effects model, and publication bias was evaluated by conducting a funnel plot. The correlation between preoperative NLR and POD was the primary outcome, and the secondary outcome was the association of other prognostic factors with the risk of POD. This meta-analysis included seven studies with 2424 patients, of whom 403 were diagnosed with POD with an incidence of 16.63%. Results indicated a positive correlation between preoperative NLR and the risk of POD (MD = 1.06, 95% CI: 0.64-1.49; P < 0.001). Further, our results found that neutrophil counts, advanced age, longer surgery time, diabetes, and elevated C-reactive protein were significantly associated with POD (MD = 0.98, 95% CI: 0.40-1.56; P = 0.001; MD = 4.20, 95% CI: 2.90-5.51; P < 0.001; MD = 0.15, 95% CI: 0.05-0.25; P < 0.01; OR = 1.42, 95% CI: 1.08-1.86; P = 0.01; MD = 1.26, 95% CI: 0.36-2.16; P < 0.01). Other factors including lymphocyte counts, hypertension and male gender were not significantly associated with POD (MD = -0.11, 95% CI: -0.27 to 0.05; P > 0.05; OR = 1.20, 95% CI: 0.91-1.58, P > 0.05; OR = 1.28, 95% CI: 1.00-1.63; P = 0.05). Our meta-analysis indicated a positive correlation between preoperative NLR and the risk of POD in older noncardiac surgery patients.

Increased TMEM166 Level in Patients with Postoperative Stroke after Carotid Endarterectomy

Postoperative stroke is a challenging and potentially devastating complication after elective carotid endarterectomy (CEA). We previously demonstrated that transmembrane protein 166 (TMEM166) levels were directly related to neuronal damage after cerebral ischemia-reperfusion injury in rats. In this subsequent clinical study, we aimed to evaluate the prognostic value of TMEM166 in patients suffering from post-CEA strokes. Thirty-five patients undergoing uncomplicated elective CEA and 8 patients who suffered ischemic strokes after CEA were recruited. We evaluated the protein level and expression of TMEM166 in patients diagnosed with postoperative strokes and compared it to those in patients who underwent uncomplicated elective CEA. Blood samples and carotid artery plaques were collected and analyzed. High expressions of TMEM166 were detected by immunofluorescence staining and Western Blot in carotid artery plaques of all patients who underwent CEA. Furthermore, circulating TMEM166 concentrations were statistically higher in post-CEA stroke patients than in patients allocated to the control group. Mean plasma concentrations of inflammatory markers, including interleukin 6 (IL-6) and C-reactive protein (CRP), were also elevated in patients with postoperative strokes. Therefore, based on these findings, we hypothesize that elevated TMEM166 levels, accompanied by a strong inflammatory response, serve as a useful biomarker for risk assessment of postoperative stroke following CEA.

Efficacy and safety of perioperative melatonin for postoperative delirium in patients undergoing surgery: a systematic review and meta-analysis

OBJECTIVE

To assess the efficacy and safety of perioperative melatonin and melatonin agonists in preventing postoperative delirium (POD).

METHODS

We conducted a systematic search for randomized controlled trials (RCTs) published through December 2022. The primary outcome was efficacy based on the incidence of POD (POD-I). Secondary outcomes included efficacy and safety according to the length of hospital or intensive care unit stay, in-hospital mortality, and adverse events. Subgroup analyses of POD-I were based on the type and dose of drug (low- and high-dose melatonin, ramelteon), the postoperative period (early or late), and the type of surgery.

RESULTS

In the analysis (16 RCTs, 1981 patients), POD-I was lower in the treatment group than in the control group (risk ratio [RR] = 0.57). POD-I was lower in the high-dose melatonin group than in the control group (RR = 0.41), whereas no benefit was observed in the low-dose melatonin and ramelteon groups. POD-I was lower in the melatonin group in the early postoperative period (RR = 0.35) and in patients undergoing cardiopulmonary surgery (RR = 0.54).

CONCLUSION

Perioperative melatonin or melatonin agonist treatment suppressed POD without severe adverse events, particularly at higher doses, during the early postoperative period, and after cardiopulmonary surgery.

Effect of remimazolam vs propofol on emergence from general anesthesia in patients undergoing cerebral endovascular procedures: A randomized controlled, non-inferiority trial

STUDY OBJECTIVE

This study aimed to compare the time to emergence from general anesthesia with remimazolam versus propofol in patients undergoing cerebral endovascular procedures.

DESIGN

A prospective, double-blind, randomized controlled, non-inferiority trial.

SETTING

An academic hospital.

PATIENTS

Adult patients scheduled for cerebral endovascular procedures.

INTERVENTIONS

Patients were randomized at a 1:1 ratio to undergo surgery under general anesthesia with remimazolam (0.1 mg kg-1 for induction and 0.3-0.7 mg kg-1 h-1 for maintenance) or propofol (1-1.5 mg kg-1 for induction and 4-10 mg kg-1 h-1 for maintenance).

MEASUREMENTS

The primary outcome was the time to emergence from anesthesia. The non-inferiority margin was -2.55 min in group difference. Major secondary outcomes included hypotension during induction, incidence of postoperative delirium and Modified Rankin Scale (mRs) at 30 days and 90 days after surgery.

MAIN RESULTS

Of the 142 randomized patients, 129 completed the trial. In the modified intention-to-treat analysis, the mean time to emergence from anesthesia was 16.1 [10.4] min in the remimazolam group vs. 19.0 [11.2] min in the propofol group. The group difference was -2.9 min [95% CI -6.5, 0.7] (P = 0.003 for non-inferiority). The remimazolam group had lower rate of hypotension during induction (11.3% vs 25.4%, P = 0.03) and use of vasopressors during surgery (29.6% vs 62.0%, P < 0.001). The two groups did not differ in postoperative delirium and mRs at 30 and 90 days after surgery.

CONCLUSIONS

In patients undergoing cerebral endovascular procedures, remimazolam did not increase the time from anesthesia vs propofol.

The association between the fibrinogen-to-albumin ratio and delirium after deep brain stimulation surgery in Parkinson's disease

Introduction

Postoperative delirium (POD) remains one of the most prevalent neuropsychiatric complications after deep brain stimulation (DBS) surgery. The fibrinogen-to-albumin ratio (FAR) has been shown to significantly correlate with the prognosis of many diseases related to inflammation. However, the association between FAR and POD remains unclear. We aimed to explore the association between POD and FAR in patients with Parkinson's disease (PD) undergoing DBS surgery.

Methods

Patients with PD who underwent DBS surgery in our hospital were included in this retrospective study. FAR was calculated from the blood sample collected on admission. The association between baseline FAR and delirium after surgery was assessed by binary logistic regression analysis, interaction analysis, and stratified analyses.

Results

Of 226 patients, 37 (16.4%) suffered from delirium after surgery. The average age of the participants was 63.3 ± 7.2 years, and 51.3% were male patients. Multivariate logistic regression analysis indicated that patients in the highest FAR tertile had a higher risk of POD compared with patients in the lowest FAR tertile (OR = 3.93, 95% CI: 1.24 ~ 12.67). Subgroup analysis demonstrated that FAR and the preoperative Mini-Mental State Examination score (p = 0.013) had an association with delirium after surgery.

Conclusion

Our data suggest that a higher preoperative FAR was significantly associated with delirium after DBS surgery. FAR on admission is a useful candidate biomarker to identify patients with PD who are at a high risk of delirium following DBS surgery.

Association of Postoperative Delirium With Incident Dementia and Graft Outcomes Among Kidney Transplant Recipients

BACKGROUND

Kidney transplant (KT) recipients have numerous risk factors for delirium, including those shared with the general surgical population (eg, age and major surgery) and transplant-specific factors (eg, neurotoxic immunosuppression medications). Evidence has linked delirium to long-term dementia risk in older adults undergoing major surgery. We sought to characterize dementia risk associated with post-KT delirium.

METHODS

Using the United States Renal Data System datasets, we identified 35 800 adult first-time KT recipients ≥55 y. We evaluated risk factors for delirium using logistic regression. We evaluated the association between delirium and incident dementia (overall and by subtype: Alzheimer's, vascular, and other/mixed-type), graft loss, and death using Fine and Gray's subhazards models and Cox regression.

RESULTS

During the KT hospitalization, 0.9% of recipients were diagnosed with delirium. Delirium risk factors included age (OR = 1.40, 95% CI, 1.28-1.52) and diabetes (OR = 1.38, 95% CI, 1.10-1.73). Delirium was associated with higher risk of death-censored graft loss (aHR = 1.52, 95% CI, 1.12-2.05) and all-cause mortality (aHR = 1.53, 95% CI, 1.25-1.89) at 5 y post-KT. Delirium was also associated with higher risk of dementia (adjusted subhazard ratio [aSHR] = 4.59, 95% CI, 3.48-6.06), particularly vascular dementia (aSHR = 2.51, 95% CI, 1.01-6.25) and other/mixed-type dementia (aSHR = 5.58, 95% CI, 4.24-7.62) subtypes. The risk of all-type dementia associated with delirium was higher for younger recipients aged between 55 and 64 y ( Pinteraction  = 0.01).

CONCLUSIONS

Delirium is a strong risk factor for subsequent diagnosis of dementia among KT recipients, particularly those aged between 55 and 64 y at the time of transplant. Patients experiencing posttransplant delirium might benefit from early interventions to enhance cognitive health and surveillance for cognitive impairment to enable early referral for dementia care.

Association of perioperative plasma concentration of neurofilament light with delirium after cardiac surgery: a nested observational study

BACKGROUND

Neurofilament light is a blood-based biomarker of neuroaxonal injury that can provide insight into perioperative brain vulnerability and injury. Prior studies have suggested that increased baseline and postoperative concentrations of neurofilament light are associated with delirium after noncardiac surgery, but results are inconsistent. Results have not been reported in cardiac surgery patients, who are among those at highest risk for delirium. We hypothesised that perioperative blood concentrations of neurofilament light (both baseline and change from baseline to postoperative day 1) are associated with delirium after cardiac surgery.

METHODS

This study was nested in a trial of arterial blood pressure targeting during cardiopulmonary bypass using cerebral autoregulation metrics. Blood concentrations of neurofilament light were measured at baseline and on postoperative day 1. The primary outcome was postoperative delirium. Regression models were used to examine the associations between neurofilament light concentration and delirium and delirium severity, adjusting for age, sex, race, logistic European System for Cardiac Operative Risk Evaluation, bypass duration, and cognition.

RESULTS

Delirium occurred in 44.6% of 175 patients. Baseline neurofilament light concentration was higher in delirious than in non-delirious patients (median 20.7 pg ml-1 [IQR 16.1-33.2] vs median 15.5 pg ml-1 [IQR 12.1-24.2], P<0.001). In adjusted models, greater baseline neurofilament light concentration was associated with delirium (odds ratio, 1.027; 95% confidence interval, 1.003-1.053; P=0.029) and delirium severity. From baseline to postoperative day 1, neurofilament light concentration increased by 42%, but there was no association with delirium.

CONCLUSIONS

Baseline neurofilament light concentration, but not change from baseline to postoperative day 1, was associated with delirium after cardiac surgery.

Effect of ultrasound-guided stellate ganglion block on inflammatory cytokines and postoperative recovery after partial hepatectomy: a randomised clinical trial

BACKGROUND

Stellate ganglion block (SGB) has been shown to reduce perioperative complications in various surgeries. Because laparoscopic techniques and instruments have advanced during the past two decades, laparoscopic liver resection is being increasingly adopted worldwide. Lesser blood loss, fewer postoperative complications, and shorter postoperative hospital stays are the advantages of laparoscopic liver resection, as compared to conventional open surgery. There is an urgent need for an effective intervention to reduce perioperative complications and accelerate postoperative recovery. This study investigated the effect of ultrasound-guided SGB on enhanced recovery after laparoscopic partial hepatectomy.

METHODS

We compared patients who received SGB with 0.5% ropivacaine (group S) with those who received SGB with 0.9% saline (group N). A total of 58 patients with partial hepatectomy were enrolled (30 S) and (28 N). Before induction of anesthesia, SGB was performed with 0.5% ropivacaine in group S and 0.9% saline in group N.

MAIN OUTCOME

Comparison of serum inflammatory cytokines concentration at each time point.

RESULTS

Main outcome: When comparing IL-6 and IL-10 concentrations among groups, group S showed less variation over time compared to group N. For comparison between groups, the serum IL-6 concentration in group S was lower than that in group N at 6 and 24 h after operation (P < 0.01), and there was a significant linear relationship between serum IL-6 concentration at 24 h after operation and hospitalization situation.

CONCLUSIONS

Ultrasound-guided SGB can stabilize perioperative inflammatory cytokines plays a positive role in the enhanced recovery of patients after laparoscopic partial hepatectomy. The serum IL-6 level within 24 h after surgery may be used as a predictor of hospitalization.

TRIAL REGISTRATION

The study was registered at the ClinicalTrials.gov (Registration date: 13/09/2021; Trial ID: NCT05042583).

Thoracic delirium index for predicting postoperative delirium in elderly patients following thoracic surgery: A retrospective case-control study

BACKGROUND

Postoperative delirium (POD) is an acute neurological complication in the elderly undergoing thoracic surgery and can result in serious adverse consequences.

AIMS

This study aimed to identify the related risk factors for POD following thoracic surgery, primarily focusing on preoperative serum biomarkers, and further to establish a novel delirium index to better predict POD.

METHODS

A total of 279 patients aged ≥60 years who underwent elective thoracic surgery from August 2021 to August 2022 were enrolled in this observational study. The platelet-to-white blood cell ratio (PWR) was calculated as number the of platelets divided by the number of white blood cells. POD was defined by the confusion assessment method twice daily during the postoperative first 3 days. Multivariate regression analysis was performed to identify all potential variables for POD. Moreover, a novel thoracic delirium index (TDI) was developed based on the related risk factors. The accuracy of TDI and its component factors in predicting POD was determined by the curve of receiver operating characteristic (ROC).

RESULTS

In total, 25 of 279 patients developed POD (8.96%). Age, PWR, and average pain scores within the first 3 days after surgery were regarded as the independent risk factors for POD. Moreover, the ROC analysis showed the TDI, including age, PWR, and average pain scores within the first 3 days after surgery, can more accurately predict POD with the largest area under the curve of 0.790 and the optimal cutoff value of 9.072, respectively.

CONCLUSION

The TDI can scientifically and effectively predict POD to provide optimal clinical guidance for older patients after thoracic surgery.

The Perioperative Frontal Relative Ratio of the Alpha Power of Electroencephalography for Predicting Postoperative Delirium After Highly Invasive Surgery: A Prospective Observational Study

BACKGROUND

We investigated the associations between postoperative delirium (POD) and both the relative ratio of the alpha (α)-power of electroencephalography (EEG) and inflammatory markers in a prospective, single-center observational study.

METHODS

We enrolled 84 patients who underwent radical cancer surgeries with reconstruction for esophageal cancer, oral floor cancer, or pharyngeal cancer under total intravenous anesthesia. We collected the perioperative EEG data and the perioperative data of the inflammatory markers, including neutrophil gelatinase-associated lipocalin, presepsin, procalcitonin, C-reactive protein, and the neutrophil-lymphocyte ratio (NLR). The existence of POD was evaluated based on the Intensive Care Delirium Screening Checklist. We compared the time-dependent changes in the relative ratio of the EEG α-power and inflammatory markers between the patients with and without POD.

RESULTS

Four of the 84 patients were excluded from the analysis. Of the remaining 80 patients, 25 developed POD and the other 55 did not. The relative ratio of the α-power at baseline was significantly lower in the POD group than the non-POD group (0.18 ± 0.08 vs 0.28 ± 0.11, P < .001). A time-dependent decline in the relative ratio of α-power in the EEG during surgery was observed in both groups. There were significant differences between the POD and non-POD groups in the baseline, 3-h, 6-h, and 9-h values of the relative ratio of α-power. The preoperative NLR of the POD group was significantly higher than that of the non-POD group (2.88 ± 1.04 vs 2.22 ± 1.00, P < .001), but other intraoperative inflammatory markers were comparable between the groups. Two multivariable logistic regression models demonstrated that the relative ratio of the α-power at baseline was significantly associated with POD.

CONCLUSIONS

Intraoperative frontal relative ratios of the α-power of EEG were associated with POD in patients who underwent radical cancer surgery. Intraoperative EEG monitoring could be a simple and more useful tool for predicting the development of postoperative delirium than measuring perioperative acute inflammatory markers. A lower relative ratio of α-power might be an effective marker for vulnerability of brain and ultimately for the development of POD.

The Potential Value of Systemic Inflammation Response Index on Delirium After Hip Arthroplasty Surgery in Older Patients: A Retrospective Study

Purpose

To explore the relationship between the systemic inflammation response index (SIRI) and postoperative delirium (POD) in older patients with hip arthroplasty surgery.

Patients and Methods

Older patients who underwent elective hip arthroplasty surgery were included in this retrospective study. SIRI, neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were collected from blood routine examination at admission. Binary logistic regression analysis was performed to evaluate the association between SIRI levels and POD was analyzed.

Results

Ultimately, 116 older patients who met the inclusion criteria were assessed. Thirty-four (29%) of 116 patients diagnosed with POD were defined as the POD group, and the rest consisted of the Non-POD group. Compared with non-POD patients, POD patients showed significantly higher levels of SIRI (P < 0.001) and NLR (P = 0.002) at admission. There was no significance in the levels of PLR between two groups. SIRI was independently associated with the occurrence of POD in multivariate logistic regression analysis [odds ratio (OR) = 3.34, 95% confidence interval (95% CI) = 1.26-8.85, P = 0.016]. Receiver operating characteristic curve analysis indicated that SIRI with an optimal cutoff value of 0.987 predicted the POD with a sensitivity of 88.2% and specificity of 74.4%, and the area under the curve was 0.82 (95% CI, 0.74-0.90, P < 0.01).

Conclusion

Preoperative SIRI and NLR levels in the blood are associated with the occurrence of POD. Moreover, preoperative SIRI level is a useful candidate biomarker to identify delirium after elective hip arthroplasty surgery in older patients.

Extracellular Vesicles as Possible Plasma Markers and Mediators in Patients with Sepsis-Associated Delirium-A Pilot Study

Patients with sepsis-associated delirium (SAD) show severe neurological impairment, often require an intensive care unit (ICU) stay and have a high risk of mortality. Hence, useful biomarkers for early detection of SAD are urgently needed. Extracellular vesicles (EVs) and their cargo are known to maintain normal physiology but also have been linked to numerous disease states. Here, we sought to identify differentially expressed proteins in plasma EVs from SAD patients as potential biomarkers for SAD. Plasma EVs from 11 SAD patients and 11 age-matched septic patients without delirium (non-SAD) were isolated by differential centrifugation, characterized by nanoparticle tracking analysis, transmission electron microscopy and Western blot analysis. Differential EV protein expression was determined by mass spectrometry and the resulting proteomes were characterized by Gene Ontology term and between-group statistics. As preliminary results because of the small group size, five distinct proteins showed significantly different expression pattern between SAD and non-SAD patients (p ≤ 0.05). In SAD patients, upregulated proteins included paraoxonase-1 (PON1), thrombospondin 1 (THBS1), and full fibrinogen gamma chain (FGG), whereas downregulated proteins comprised immunoglobulin (IgHV3) and complement subcomponent (C1QC). Thus, plasma EVs of SAD patients show significant changes in the expression of distinct proteins involved in immune system regulation and blood coagulation as well as in lipid metabolism in this pilot study. They might be a potential indicator for to the pathogenesis of SAD and thus warrant further examination as potential biomarkers, but further research is needed to expand on these findings in longitudinal study designs with larger samples and comprehensive polymodal data collection.

The Association between Dietary Habits and Rapid Postoperative Recovery of Rotator Cuff Repair

Some nutritional factors have been suggested to improve postoperative outcomes in rotator cuff (RC) repair, but dietary effects on the recovery speed after the surgery remain undefined. To investigate the potential roles of dietary habits in this context, we analyzed the 12-month follow-up data of 55 patients with RC repair and found that these patients could be categorized into a rapid recovery group (n = 35) and slow recovery group (n = 20) according to their postoperative recovery patterns. Group-based logistic analysis revealed that habitual intakes of meat (OR = 1.84, 95%CI, 1.22-2.76, p = 0.003), fruits (OR = 2.33, 95%CI, 1.26-5.67, p = 0.01), and wheat-flour foods (OR = 1.62, 95%CI, 1.2-2.25, p = 0.002) were significantly associated with rapid recovery. Moreover, among all intakes of wheat-flour foods, intakes of steamed and boiled flour products were also associated with rapid recovery. Further mediation analysis showed that eosinophilic granulocytes (EOs) significantly mediated the association between rapid RC recovery and the habitual intakes of meat (mediation proportion = 17.5%, P-mediation < 0.0001), fruits (17.9%, p < 0.0001), and wheat-flour foods (11.4%, p < 0.0001). Thus, our study suggests that certain dietary habits play beneficial roles in the context of postoperative recovery for RC repair.

Perioperative Factors Associated With Postoperative Delirium in Patients Undergoing Noncardiac Surgery: An Individual Patient Data Meta-Analysis

Importance

Postoperative delirium (POD) is a common and serious complication after surgery. Various predisposing factors are associated with POD, but their magnitude and importance using an individual patient data (IPD) meta-analysis have not been assessed.

Objective

To identify perioperative factors associated with POD and assess their relative prognostic value among adults undergoing noncardiac surgery.

Data Sources

MEDLINE, EMBASE, and CINAHL from inception to May 2020.

Study Selection

Studies were included that (1) enrolled adult patients undergoing noncardiac surgery, (2) assessed perioperative risk factors for POD, and (3) measured the incidence of delirium (measured using a validated approach). Data were analyzed in 2020.

Data Extraction and Synthesis

Individual patient data were pooled from 21 studies and 1-stage meta-analysis was performed using multilevel mixed-effects logistic regression after a multivariable imputation via chained equations model to impute missing data.

Main Outcomes and Measures

The end point of interest was POD diagnosed up to 10 days after a procedure. A wide range of perioperative risk factors was considered as potentially associated with POD.

Results

A total of 192 studies met the eligibility criteria, and IPD were acquired from 21 studies that enrolled 8382 patients. Almost 1 in 5 patients developed POD (18%), and an increased risk of POD was associated with American Society of Anesthesiologists (ASA) status 4 (odds ratio [OR], 2.43; 95% CI, 1.42-4.14), older age (OR for 65-85 years, 2.67; 95% CI, 2.16-3.29; OR for >85 years, 6.24; 95% CI, 4.65-8.37), low body mass index (OR for body mass index <18.5, 2.25; 95% CI, 1.64-3.09), history of delirium (OR, 3.9; 95% CI, 2.69-5.66), preoperative cognitive impairment (OR, 3.99; 95% CI, 2.94-5.43), and preoperative C-reactive protein levels (OR for 5-10 mg/dL, 2.35; 95% CI, 1.59-3.50; OR for >10 mg/dL, 3.56; 95% CI, 2.46-5.17). Completing a college degree or higher was associated with a decreased likelihood of developing POD (OR 0.45; 95% CI, 0.28-0.72).

Conclusions and Relevance

In this systematic review and meta-analysis of individual patient data, several important factors associated with POD were found that may help identify patients at high risk and may have utility in clinical practice to inform patients and caregivers about the expected risk of developing delirium after surgery. Future studies should explore strategies to reduce delirium after surgery.

The relationship between major depression and delirium: A two-sample Mendelian randomization analysis

BACKGROUND

Major depression (MD) is a well-recognized risk factor for delirium. However, observational studies cannot provide direct evidence of causality between MD and delirium.

METHODS

This study explored the genetic causal association between MD and delirium using two-sample Mendelian randomization (MR). Genome-wide association study (GWAS) summary data for MD were obtained from the UK Biobank. GWAS summary data for delirium were obtained from the FinnGen Consortium. Inverse-variance weighted (IVW), MR Egger, weighted median, simple mode, and weighted mode were used to perform the MR analysis. In addition, the Cochrane's Q test was used to detect heterogeneity in the MR results. Horizontal pleiotropy was detected using the MR-Egger intercept test and MR pleiotropy residual sum and outliers (MR-PRESSO) test. Leave-one-out analysis was used to investigate the sensitivity of this association.

RESULTS

The IVW method showed that MD was an independent risk factor for delirium (P = 0.013). Horizontal pleiotropy was unlikely to bias causality (P > 0.05), and no evidence of heterogeneity was found between the genetic variants (P > 0.05). Finally, a leave-one-out test showed that this association was stable and robust.

LIMITATIONS

All participants included in the GWAS were of European ancestry. Due to database limitations, the MR analysis did not conduct stratified analyses for different countries, ethnicities, or age groups.

CONCLUSION

We conducted a two-sample MR analysis and found the evidence of genetic causal association between MD and delirium.

The role of hormones in the pathogenesis and treatment mechanisms of delirium in ICU: The past, the present, and the future

Delirium is an acute brain dysfunction. As one of the common psychiatric disorders in ICU, it can seriously affect the prognosis of patients. Hormones are important messenger substances found in the human body that help to regulate and maintain the function and metabolism of various tissues and organs. They are also one of the most commonly used drugs in clinical practice. Recent evidences suggest that aberrant swings in cortisol and non-cortisol hormones might induce severe cognitive impairment, eventually leading to delirium. However, the role of hormones in the pathogenesis of delirium still remains controversial. This article reviews the recent research on risk factors of delirium and the association between several types of hormones and cognitive dysfunction. These mechanisms are expected to offer novel ideas and clinical relevance for the treatment and prevention of delirium.

Inflammatory biomarkers and delirium: a Mendelian randomization study

Background

The association between inflammatory biomarkers and individual delirium symptoms remains controversial in observational studies. We investigated the relationship between inflammatory biomarkers and the risk of developing delirium.

Methods

A bidirectional two-sample Mendelian randomization (MR) was performed. Genetic instruments associated with peripheral tumor necrosis factor-a (TNF-a) C-reactive protein (CRP), interleukin (IL)-1α, IL-1β, IL-2, IL-8, IL-6, soluble IL-6 receptor alpha (sIL-6Rα), and soluble gp130 were identified in three different large summary genome-wide association studies (GWAS) conducted in the European population. Summary-level statistics for delirium not induced by alcohol and other psychoactive substances were obtained from the FinnGen consortium (2,612 cases and 325,306 controls). The estimated causal effects were performed using instruments' variants at the genome-wide significant level (P < 5e-8 and P < 5e-6), applying a linkage disequilibrium clumping approach with a threshold of r2 < 0.001 for each of the exposures. Reverse causation was also performed. The inverse-variance weighted method (IVW), MR-Egger method, weighted median method, MR-Egger regression, and MR Pleiotropy RESidual Sum were used for MR analyses.

Results

At the genome-wide significant level (P < 5e-8, r2 < 0.001), genetically predicted sIL-6Rα was significantly associated with a decreased risk of delirium with less than three single-nucleotide polymorphisms (SNPs) in all three GWAS data sources (ORWaldratio = 0.89, 95% CI: 0.79-0.96, PWaldratio = 0.0016; ORIVW = 0.88, 95% CI: 0.79-0.97, PIVW = 0.008; ORIVW = 0.88, 95% CI: 0.80-0.96, PIVW = 0.004). The causal relationship between sIL-6Rα and delirium became non-significant when a more liberal threshold of P of < 5e-6 was applied (all PIVW > 0.05). At the two genome-wide significance levels (P < 5e-8 and P < 5e-6), we found no evidence for the causal effects of peripheral TNF-α, CRP, IL-1α, IL-1β, IL-2, IL-6, IL-8, and soluble gp130 on delirium (all P > 0.05). The MR-Egger intercept and MR-PRESSO results indicated that no SNP had possible pleiotropy (all P > 0.05). Regarding the reverse, no evidence for an effect of delirium on these inflammatory biomarkers could be found (all P > 0.05).

Conclusion

The results of this MR analysis did not support that peripheral TNF-α, CRP, IL-1α, IL-1β, IL-2, IL-6, sIL-6Rα, soluble gp130, and IL-8 were causally associated with delirium. More research is needed to explore the role of inflammatory factors in the pathogenesis of delirium.

Platform trials for anaesthesia and perioperative medicine: a narrative review

Large randomised trials provide the most reliable evidence of effectiveness of new treatments in clinical practice. However, the time and resources required to complete such trials can be daunting. An overarching clinical trial platform focused on a single condition or type of surgery, aiming to compare several treatments, with an option to stop any or add in new treatment options, can provide greater efficiency. This has the potential to accelerate knowledge acquisition and identify effective, ineffective, or harmful treatments faster. The master protocol of the platform defines the study population(s) and standardised procedures. Ineffective or harmful treatments can be discarded or study drug dose modified during the life cycle of the trial. Other adaptive elements that can be modified include eligibility criteria, required sample size for any comparison(s), randomisation assignment ratio, and the addition of other promising treatment options. There are excellent opportunities for anaesthetists to establish platform trials in perioperative medicine. Platform trials are highly efficient, with the potential to provide quicker answers to important clinical questions that lead to improved patient care.

[Postoperative delirium in the recovery room]

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

Biomarkers of delirium risk in older adults: a systematic review and meta-analysis

Delirium is a neuropsychiatric syndrome associated with increased morbidity and mortality in older patients. The aim of this study was to review predictive biomarkers of delirium in older patients to gain insights into the pathophysiology of this syndrome and provide guidance for future studies. Two authors independently and systematically searched MEDLINE, Embase, Cochrane Library, Web of Science and Scopus databases up to August 2021. A total of 32 studies were included. Only 6 studies were eligible for the meta-analysis, pooled results showed a significant increase in some serum biomarkers (C-reactive protein [CRP], tumour necrosis factor alpha [TNF-α] and interleukin-6 [IL-6]) among patients with delirium (odds ratio = 1.88, 95% CI 1.01 to 1.637; I2 = 76.75%). Although current evidence does not favour the use of any particular biomarker, serum CRP, TNF-α, and IL-6 were the most consistent biomarkers of delirium in older patients.

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

INTRODUCTION

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

MATERIALS AND METHODS

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

RESULTS

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

DISCUSSION

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

Processed electroencephalography-guided general anaesthesia to reduce postoperative delirium: a systematic review and meta-analysis

BACKGROUND

Postoperative delirium (POD) is the most common serious postoperative complication in older adults. It has uncertain aetiology, limited preventative strategies, and poor long-term outcomes. This updated systematic review and meta-analysis aimed to estimate the effect of processed electroencephalography (pEEG)-guided general anaesthesia during surgery on POD incidence.

METHODS

We performed a systematic review and meta-analysis by searching OVID MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) electronic databases. Studies of adult patients having general anaesthesia for any surgery where pEEG was used and POD was an outcome measure were included. Full-text reports of RCTs published from database inception until August 28, 2021, were included. Trials were excluded if sedation rather than general anaesthesia was administered, or the setting was intensive care. The primary outcome was POD assessed by validated tools. The study was prospectively registered with PROSPERO.

RESULTS

Nine studies, which included 4648 eligible subjects, were identified. The incidence of POD in the pEEG-guided general anaesthesia or lighter pEEG target group was 19.0% (440/2310) compared with 23.3% (545/2338) in the usual care or deeper pEEG target group (pooled odds ratio=0.78; 95% confidence interval, 0.60-1.00; P=0.054). Significant heterogeneity was detected (I²=53%).

CONCLUSIONS

Our primary analysis demonstrated a highly sensitive result with a pooled analysis of trials in which the intervention group adhered to manufacturer's recommended guidelines, showing reduced incidence of POD with pEEG guidance. High clinical heterogeneity limits inferences from this and any future meta-analyses.

CLINICAL TRIAL REGISTRATION

CRD42020199404 (PROSPERO).

Defining the role of Interleukin-6 for the development of perioperative neurocognitive disorders: Evidence from clinical and preclinical studies

For most, staying "mentally sharp" as they age is a very high priority that may be thwarted by the consequences of a postoperative complication unrelated to the disorder which necessitated the surgical intervention. Perioperative neurocognitive disorder (PND) is an overarching term for cognitive impairment in surgical patients, that includes conditions from delirium to dementia, affecting more than 7 million patients annually in the US, and which threatens both functional independence and life. Clinical trials and meta-analyses have identified the association between PNDs and increased perioperative levels of Interleukin-6 (IL-6), a pleiotropic cytokine that is both necessary and sufficient for postoperative memory decline in a preclinical model of PND. Recently, we reported that, in adult male wild-type mice subjected to tibial fracture under general anesthesia, IL-6 trans-signaling in hippocampal CA1 neurons mediates surgery-induced memory impairment. As there are no therapeutic options for preventing or reversing PNDs, patients and their caregivers, as well as the healthcare industry, endure staggering costs. Olamkicept, a highly selective IL-6 trans-signaling blocker has shown to be efficacious and safe in clinical trials involving patients with inflammatory bowel disease, another condition for which IL-6 trans-signaling is the mediating mechanism. Subject to a demonstration that olamkicept is effective in preventing cognitive impairment in vulnerable (aged and Alzheimer's Disease) preclinical PND models, clinical trials involving aged and/or cognitively impaired surgical patients should be undertaken to study olamkicept's utility for PNDs.

Age-Related Perioperative Neurocognitive Disorders: Experimental Models and Druggable Targets

With the worldwide increase in life span, surgical patients are becoming older and have a greater propensity for postoperative cognitive impairment, either new onset or through deterioration of an existing condition; in both conditions, knowledge of the patient's preoperative cognitive function and postoperative cognitive trajectory is imperative. We describe the clinical utility of a tablet-based technique for rapid assessment of the memory and attentiveness domains required for executive function. The pathogenic mechanisms for perioperative neurocognitive disorders have been investigated in animal models in which excessive and/or prolonged postoperative neuroinflammation has emerged as a likely contender. The cellular and molecular species involved in postoperative neuroinflammation are the putative targets for future therapeutic interventions that are efficacious and do not interfere with the surgical patient's healing process.

Association of preoperative prognostic nutritional index with risk of postoperative delirium: A systematic review and meta-analysis

STUDY OBJECTIVE

To assess the association between prognostic nutritional index (PNI) and risk of postoperative delirium (POD) in adult patients.

METHODS

MEDLINE, Google scholar, EMBASE, and Cochrane library databases were searched from inception till April 2022. The primary outcome was the association between PNI and the risk of POD, while the secondary outcomes were correlations of other prognostic factors with POD risk. The correlation between PNI and the incidence of POD was assessed with three approaches: Difference in preoperative PNI between POD and non-POD groups (Model 1) as well as the association of PNI as a continuous parameter (Model 2) or as a binary variable (i.e., low vs. high using a PNI cut-off value of 50) (Model 3) with POD risk.

RESULTS

Analysis of nine observational studies published from 2010 to 2021 recruiting 3,743 patients showed a POD incidence of 6.4-35%. Our meta-analysis demonstrated a lower PNI among patients in the POD group (MD: -3.78, 95% CI: -4.85 to -2.71, p < 0.0001, I 2 = 54.2%) compared to the non-POD group (Model 1). Pooled results revealed a negative association between PNI and POD risk for both Model 2 (OR: 0.91, 95% CI: 0.86-0.97, p = 0.002, I 2 = 71%) and Model 3 (OR: 1.68, 95% CI: 1.26-2.23, p < 0.0001, I 2 = 0%). Besides, while our results supported an age-dependent increase in POD risk, other factors including body-mass index, surgical time, health status, hypertension, diabetes mellitus, and male gender were non-significant predictors of POD.

CONCLUSION

Our results demonstrated a negative association between PNI and POD, which warrant further large-scale studies for validation.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/, identifier CRD42022323809.

The effect of parecoxib sodium on postoperative delirium in elderly patients with hip arthroplasty

Objective: This study aimed to clarify the effect of parecoxib sodium on the occurrence of postoperative delirium and to investigate its possible mechanism. Methods: A total of 80 patients who underwent elective hip arthroplasty in our hospital between December 2020 and December 2021 were selected and randomly divided into two groups: a parecoxib sodium group (group P, n = 40) and a control group (group C, n = 40). Patients in group P were intravenously injected with 40 mg of parecoxib sodium 30 min before anesthesia and at the end of the surgery. Patients in group C were intravenously injected with the same volume of normal saline at the same time points. The primary endpoint was the incidence of POD, and the secondary endpoints were the levels of inflammatory factors (tumor necrosis factor- α [TNF-α], interleukin [IL]-1β, IL-6, and IL-10), nerve injury-related factors (brain-derived neurotrophic factor [BDNF], S-100β protein, neuron-specific enolase [NSE], and neurofilament light chain [NfL]), and antioxidant factors (heme oxygenase-1 [HO-1]), as well as the Visual Analogue Scale (VAS) and Confusion Assessment Method-Chinese Reversion (CAM-CR) scores. Results: The incidence of POD was 10% in group P and 27.5% in group C. Intergroup comparison revealed that the levels of TNF-α, IL-1β, S-100β, NfL, and NSE were lower, and BDNF was higher, in group P than in group C at each postoperative time point. The levels of IL-6 were lower, and the levels of IL-10 and HO-1 were higher, in group P than in group C at 1 h and 1 day postoperatively (p < 0.05). Three days after surgery, the differences in the levels of IL-6, IL-10, and HO-1 were not statistically significant between the two groups (p > 0.05). The VAS and CAM-CR scores were lower at each postoperative time point in group P than in group C (p < 0.05). Conclusion: Parecoxib sodium could reduce postoperative pain, decrease the plasma levels of inflammatory and nerve injury-related factors, upregulate HO-1 levels, and reduce the incidence of POD. The results of this study suggest that parecoxib sodium may reduce the occurrence of POD through the effects of anti-inflammation, analgesia, and antioxidants.

Longitudinal Profiling of Plasma Cytokines and Its Association With Postoperative Delirium in Elderly Patients Undergoing Major Lower Limb Surgery: A Prospective Observational Study

BACKGROUND

Surgery is accompanied by a systemic inflammatory response that may presage delirium in susceptible individuals. Little is known about the trajectory of plasma proinflammatory cytokines and their potential associations with postoperative delirium (POD). The current study longitudinally assessed both pro and anti-inflammatory plasma cytokine response and development of POD in older surgical patients to investigate associations with individual and/or clusters of cytokines that may indicate pathogenic mechanisms.

METHODS

A prospective longitudinal study sought to enroll patients >60 years old who were scheduled for major lower limb surgery under general anesthesia. Blood was obtained preoperatively and postoperatively from day 1 through postoperative day 4 for measurement of plasma interleukin-1β (IL-1β), IL-2, IL-4, IL-6, soluble IL-6 receptor (sIL-6R), IL-10, and tumor necrosis factor-α (TNF-α). Participants were assessed for POD twice daily for 4 days using the confusion assessment method. Trajectory of postoperative changes in plasma cytokines was determined by a group-based trajectory modeling analysis that was informed by distinct cytokines identified by time-dependent Cox regression model.

RESULTS

One hundred eighty-eight patients were assessed for eligibility of whom 129 underwent major surgery and 126 had complete datasets for final analysis. POD was diagnosed in 31 of 126 patients (24.6%). Time-dependent Cox regression model identified that higher IL-6 and sIL-6R levels were associated with higher risk of developing POD. A two-cluster model (stable lower and fluctuating higher levels) was considered to be the most statistically appropriate model for IL-6 and sIL-6R trajectory. More participants with fluctuating higher IL-6 were delirious (73.3% vs 18.0%, P = .001) as were those with fluctuating higher sIL-6R (81.3% vs 16.4%, P = .001).

CONCLUSIONS

As higher IL-6 and sIL-6R levels were significantly associated with higher risk of POD and the combination is required for IL-6 trans-signaling, it is possible that activation of this pathway may be associated with POD. Furthermore, it will be important to determine whether high levels of the combination of IL-6 and sIL-6R can be an early biomarker for the subsequent development of POD.