Breaking barriers in postoperative delirium

Association of preoperative to postoperative change in cerebrospinal fluid fibrinogen with postoperative delirium

Background

We aimed to assess perioperative changes in fibrinogen in the cerebrospinal fluid (CSF), their association with markers of blood-brain barrier breakdown and neuroinflammation, and their association with postoperative delirium severity.

Methods

We conducted a secondary analysis of the Interventions for Postoperative Delirium-Biomarker 2 (IPOD-B2, NCT02926417) study, a prospective observational cohort study. We included 24 patients aged >21 yr undergoing aortic aneurysm repair. CSF samples were obtained before (n=24) and after surgery (n=13), with some participants having multiple postoperative samples. Our primary outcome was the perioperative change in CSF fibrinogen. Delirium was assessed using the Delirium Rating Scale-Revised-98.

Results

CSF fibrinogen increased after surgery (P<0.001), and this was associated with an increase in CSF/plasma albumin ratio (β=1.09, 95% CI 0.47-1.71, P=0.004). The peak change in CSF fibrinogen was associated with the change in CSF interleukin (IL)-10 and IL-12p70. The peak change in CSF fibrinogen was associated with the change in CSF total tau (β=0.47, 95% CI 0.24-0.71, P=0.002); however, we did not observe an association with postoperative delirium severity (incidence rate ratio = 1.20, 95% CI 0.66-2.17, P=0.540).

Conclusions

Our preliminary findings support the hypothesis that fibrinogen enters the brain via blood-brain barrier disruption, promoting neuroinflammation and neuronal injury. However, we did not observe an association between cerebrospinal fluid fibrinogen and peak delirium severity in this limited cohort.

Emerging Insights into Postoperative Neurocognitive Disorders: The Role of Signaling Across the Gut-Brain Axis

The pathophysiological regulatory mechanisms in postoperative neurocognitive disorders (PNCDs) are intricately complex. Currently, the pathogenesis of PNCDs has not been fully elucidated. The mechanism involved may include a variety of factors, such as neuroinflammation, oxidative stress, and neuroendocrine dysregulation. Research into the gut microbiota-induced regulations on brain functions is increasingly becoming a focal point of exploration. Emerging evidence has shown that intestinal bacteria may play an essential role in maintaining the homeostasis of various physiological systems and regulating disease occurrence. Recent studies have confirmed the association of the gut-brain axis with central nervous system diseases. However, the regulatory effects of this axis in the pathogenesis of PNCDs remain unclear. Therefore, this paper intends to review the bidirectional signaling and mechanism of the gut-brain axis in PNCDs, summarize the latest research progress, and discuss the possible mechanism of intestinal bacteria affecting nervous system diseases. This review is aimed at providing a scientific reference for predicting the clinical risk of PNCD patients and identifying early diagnostic markers and prevention targets.

AI-Assisted Identification of Primary and Secondary Metabolomic Markers for Postoperative Delirium

Despite considerable investigative efforts, the molecular mechanisms of postoperative delirium (POD) remain unresolved. The present investigation employs innovative methodologies for identifying potential primary and secondary metabolic markers of POD by analyzing serum metabolomic profiles utilizing the genetic algorithm and artificial neural networks. The primary metabolomic markers constitute a combination of metabolites that optimally distinguish between POD and non-POD groups of patients. Our analysis revealed L-lactic acid, inositol, and methylcysteine as the most salient primary markers upon which the prediction accuracy of POD manifestation achieved AUC = 99%. The secondary metabolomic markers represent metabolites that exhibit perturbed correlational patterns within the POD group. We identified 54 metabolites as the secondary markers of POD, incorporating neurotransmitters such as gamma-aminobutyric acid (GABA) and serotonin. These findings imply a systemic disruption in metabolic processes in patients with POD. The deployment of gene network reconstruction techniques facilitated the postulation of hypotheses describing the role of established genomic POD markers in the molecular-genetic mechanisms of metabolic pathways dysregulation, and involving the identified primary and secondary metabolomic markers. This study not only expands the understanding of POD pathogenesis but also introduces a novel technology for the bioinformatic analysis of metabolomic data that could aid in uncovering potential primary and secondary markers in diverse research domains.

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.

Delirium in trauma ICUs: a review of incidence, risk factors, outcomes, and management

PURPOSE OF REVIEW

This article reviews the impact and importance of delirium on patients admitted to the ICU after trauma, including the latest work on prevention and treatment of this condition. As the population ages, the incidence of geriatric trauma will continue to increase with a concomitant rise in the patient and healthcare costs of delirium in this population.

RECENT FINDINGS

Recent studies have further defined the risk factors for delirium in the trauma ICU patient population, as well as better demonstrated the poor outcomes associated with the diagnosis of delirium in these patients. Recent trials and meta-analysis offer some new evidence for the use of dexmedetomidine and quetiapine as preferred agents for prevention and treatment of delirium and add music interventions as a promising part of nonpharmacologic bundles.

SUMMARY

Trauma patients requiring admission to the ICU are at significant risk of developing delirium, an acute neuropsychiatric disorder associated with increased healthcare costs and worse outcomes including increased mortality. Ideal methods for prevention and treatment of delirium are not well established, especially in this population, but recent research helps to clarify optimal prevention and treatment strategies.