Impact of length of red blood cells transfusion on postoperative delirium in elderly patients undergoing hip fracture surgery: A cohort study

The NF-κB pathway: Key players in neurocognitive functions and related disorders

Perioperative neurocognitive disorder (PND) is a common complication of surgical anesthesia, yet its precise etiology remains unclear. Neuroinflammation is a key feature of PND, influenced by both patient -related and surgical variables. The nuclear factor-κB (NF-κB) transcription factor family plays a critical role in regulating the body's immunological proinflammatory response, which is pivotal in the development of PND. Surgery and anesthesia trigger the activation of the NF-κB signaling pathway, leading to the initiation of inflammatory cascades, disruption of the blood-brain barrier, and neuronal injury. Immune cells and glial cells are central to these pathological processes in PND. Furthermore, this study explores the interactions between NF-κB and various signaling molecules, including Tlr4, P2X, α7-nAChR, ROS, HIF-1α, PI3K/Ak, MicroRNA, Circular RNA, and histone deacetylases, within the context of PND. Targeting NF-κB as a therapeutic approach for PND shows promise as a potential treatment strategy.

Free heme induces neuroinflammation and cognitive impairment by microglial activation via the TLR4/MyD88/NF-κB signaling pathway

BACKGROUND

Red blood cells (RBCs) transfusion is related to perioperative neurocognitive disorders. The toxic effect of free heme has been identified in many pathologies. However, the underlying mechanisms of RBCs transfusion or free heme in cognitive impairment have not been clearly explored. Therefore, this research was conducted to determine the mechanism of free heme-induced neuroinflammation and cognitive impairment.

METHODS

Rats were received intraperitoneal injection of hemin alone or combined with intracerebroventricular injection of Hemopexin (HPX), and MWM test was conducted to measure cognitive function. The amount of heme-HPX complexes was evaluated by flow cytometry for CD91 + cells. The microglial inflammatory response in rat brain was observed by immunofluorescence staining of Iba-1, and the inflammatory factors of TNF-α, IL-1β and IL-6 in rat brain and BV2 cells were detected by ELISA analysis. Furthermore, neuronal apoptosis in HT22 cells alone and in HT22 + BV2 coculture system was detected by flow cytometry and immunofluorescence staining. Finally, western blot was conducted to detect TLR4/MyD88/NF-κB proteins in rat brain and BV2 cells treated with hemin or combined with pathway inhibitors. Additionally, the M1 surface marker CD86 was observed in BV2 cells to further confirm neuroinflammation.

RESULTS

Intraperitoneal injection of hemin induced cognitive impairment, increase of CD91 + cells, up-regulation of TNF-α and IL-1β, down-regulation of IL-6, activation of microglia, and activation of the TLR4/MyD88/NF-κB signaling pathway in rat brain. Significantly, intracerebroventricular injection of HPX reduced the above effects. Hemin induced boost of TNF-α, IL-1β and IL-6 in BV2 cells, as well as apoptosis in HT22 cells. Notably, when HT22 cells were cocultured with BV2 cells, apoptosis was significantly increased. Hemin also induced activation of the TLR4/MyD88/NF-κB signaling pathway and increased the M1 surface marker CD86 in BV2 cells, and inhibiting this pathway reduced the inflammatory responses.

CONCLUSIONS

Free heme induces cognitive impairment, and the underlying mechanism may involve neuronal apoptosis and microglial inflammation via the TLR4/MyD88/NF-κB signaling pathway. HPX may have potential therapeutic effects. Video Abstract.

The Impact of Blood Transfusion in Developing Postoperative Delirium in Patients with Hip Fracture Surgery

BACKGROUND

Many studies have been conducted to explore the risk factors associated with postoperative delirium (POD) in order to understand its underlying causes and develop prevention strategies, especially for hip fracture surgery. However, the relationship between blood transfusion and POD has been heatedly debated. The purpose of this study was to evaluate the risk factors of POD and the relationship between blood transfusions and the occurrence of POD in hip fracture surgery through big data analysis.

METHODS

Medical data (including medication history, clinical and laboratory findings, and perioperative variables) were acquired from the clinical data warehouse (CDW) of the five hospitals of Hallym University Medical Center and were compared between patients without POD and with POD.

RESULTS

The occurrence of POD was 18.7% (228 of 2398 patients). The risk factors of POD included old age (OR 4.38, 95% CI 2.77-6.91; p < 0.001), American Society of Anesthesiology physical status > 2 (OR 1.84 95% CI 1.4-2.42; p < 0.001), dementia (OR 1.99, 95% CI 1.53-2.6; p < 0.001), steroid (OR 0.53 95% CI 0.34-0.82; p < 0.001), Antihistamine (OR 1.53 95% CI 1.19-1.96; p < 0.001), and postoperative erythrocyte sedimentation rate (mm/h) (OR 0.97 95% CI 0.97-0.98; p < 0.001) in multivariate logistic regression analysis. The postoperative transfusion (OR 2.53, 95% CI 1.88-3.41; p < 0.001) had a significant effect on the incidence of POD.

CONCLUSIONS

big data analytics using a CDW was a good option to identify the risk factors of POD and to prevent POD in hip fracture surgery.

Preoperative Risk Factors Associated with Increased Incidence of Postoperative Delirium: Systematic Review of Qualified Clinical Studies

Postoperative delirium (POD) is an acute alteration of mental state, characterized by reduced awareness and attention, occurring up to five postoperative days after recovery from anesthesia. Several original studies and reviews have identified possible perioperative POD risk factors; however, there is no comprehensive review of the preoperative risk factors in patients diagnosed with POD using only validated diagnostic scales. The aim of this systematic review was to report the preoperative risk factors associated with an increased incidence of POD in patients undergoing non-cardiac and non-brain surgery. The reviewed studies included original research papers that used at least one validated diagnostic scale to identify POD occurrence for more than 24 h. A total of 6475 references were retrieved from the database search, with only 260 of them being suitable for further review. Out of the 260 reviewed studies, only 165 that used a validated POD scale reported one or more preoperative risk factors. Forty-one risk factors were identified, with various levels of statistical significance. The extracted risk factors could serve as a preoperative POD risk assessment workup. Future studies dedicated to the further evaluation of the specific preoperative risk factors' contributions to POD could help with the development of a weighted screening tool.

Transfusion-Associated Delirium in Children: No Difference Between Short Storage Versus Standard Issue RBCs

OBJECTIVES

Primary objective is to determine if transfusion of short storage RBCs compared with standard issue RBCs reduced risk of delirium/coma in critically ill children. Secondary objective is to assess if RBC transfusion was independently associated with delirium/coma.

DESIGN

This study was performed in two stages. First, we compared patients receiving either short storage or standard RBCs in a multi-institutional prospective randomized controlled trial. Then, we compared all transfused patients in the randomized controlled trial with a single-center cohort of nontransfused patients matched for confounders of delirium/coma.

SETTING

Twenty academic PICUs who participated in the Age of Transfused Blood in Critically Ill Children trial.

PATIENTS

Children 3 days to 16 years old who were transfused RBCs within the first 7 days of admission.

INTERVENTIONS

Subjects were randomized to either short storage RBC study arm (defined as RBCs stored for up to seven days) or standard issue RBC study arm. In addition, subjects were screened for delirium prior to transfusion and every 12 hours after transfusion for up to 3 days.

MEASUREMENTS AND MAIN RESULTS

Primary outcome measure was development of delirium/coma within 3 days of initial transfusion. Additional outcome measures were dose-response relationship between volume of RBCs transfused and delirium/coma, and comparison of delirium/coma rates between transfused patients and individually matched nontransfused patients. We included 146 subjects in the stage I analysis; 69 were randomized to short storage RBCs and 77 to standard issue. There was no significant difference in delirium/coma development between study arms (79.5% vs 70.1%; p = 0.184). In the stage II analysis, adjusted odds for delirium in the transfused cohort was more than eight-fold higher than in the nontransfused matched cohort, even after controlling for hemoglobin (adjusted odds ratio, 8.9; CI, 2.8-28.4; p < 0.001).

CONCLUSIONS

RBC transfusions (and not anemia) are independently associated with increased odds of subsequent delirium/coma. However, storage age of RBCs does not affect delirium risk.

Red Blood Cell Transfusion and Postoperative Delirium in Hip Fracture Surgery Patients: A Retrospective Observational Cohort Study

Background

Patients having hip fracture surgery are at high risk for postoperative delirium. Red blood cell (RBC) transfusion may increase postoperative delirium risk by causing neuroinflammation. We hypothesized that RBC transfusion would be associated with postoperative delirium in patients having hip fracture surgery.

Methods

An observational cohort study was performed using the United States National Surgical Quality Improvement Program (NSQIP) participant use files for hip fracture from 2016 to 2018. Propensity score analysis and inverse probability of treatment weighting (IPTW) were used to reduce bias from confounding. An IPTW adjusted odds ratio for developing postoperative delirium was calculated for patients who received RBC transfusion during surgery or in the 72 hours after.

Results

There were 20,838 patients who had eligible current procedural terminology (CPT) codes for primary hip fracture surgery and complete study data. After employing strict exclusions to balance covariates and reduce bias, 3,715 patients remained in the IPTW cohort. Of these, 626 patients (16.9%) received RBC transfusion and 665 patients (17.9%) developed postoperative delirium. IPTW adjustment led to good covariate balance between patients who received RBC transfusion and those who did not. Patients who received RBC transfusion had significantly higher odds of postoperative delirium, IPTW adjusted odds ratio = 1.21, 95% CI = 1.03 to 1.43, and P = 0.02. Discharge location also differed significantly between patients who received RBC transfusion and those who did not (P < 0.001) with in-hospital mortality or referral to hospice occurring in 1.6% of patients who received RBC transfusion and 1.3% of patients who were not transfused.

Conclusion

RBC transfusion is associated with increased odds of postoperative delirium after hip fracture surgery and may be associated with worse clinical outcome.

Independent Association Between Type of Intraoperative Blood Transfusion and Postoperative Delirium After Complex Spinal Fusion for Adult Deformity Correction

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To determine whether type of intraoperative blood transfusion used is associated with increased incidence of postoperative delirium after complex spine fusion involving five levels or greater.

SUMMARY OF BACKGROUND DATA

Postoperative delirium after spine surgery has been associated with age, cognitive status, and several comorbidities. Intraoperative allogenic blood transfusions have previously been linked to greater complication risks and length of hospital stay. However, whether type of intraoperative blood transfusion used increases the risk for postoperative delirium after complex spinal fusion remains relatively unknown.

METHODS

The medical records of 130 adult (≥18 years old) spine deformity patients undergoing elective, primary complex spinal fusion (more than or equal to five levels) for deformity correction at a major academic institution from 2010 to 2015 were reviewed. We identified 104 patients who encountered an intraoperative blood transfusion. Of the 104, 15 (11.5%) had Allogenic-only, 23 (17.7%) had Autologous-only, and 66 (50.8%) had Combined transfusions. The primary outcome investigated was the rate of postoperative delirium.

RESULTS

There were significant differences in estimated blood loss (Combined: 2155.5 ± 1900.7 mL vs. Autologous: 1396.5 ± 790.0 mL vs. Allogenic: 1071.3 ± 577.8 mL vs. None: 506.9 ± 427.3 mL, P < 0.0001) and amount transfused (Combined: 1739.7 ± 1127.6 mL vs. Autologous: 465.7 ± 289.7 mL vs. Allogenic: 986.9 ± 512.9 mL, P < 0.0001). The Allogenic cohort had a significantly higher proportion of patients experiencing delirium (Combined: 7.6% vs. Autologous: 17.4% vs. Allogenic: 46.7% vs. None: 11.5%, P = 0.002). In multivariate nominal-logistic regression analysis, Allogenic (odds ratio [OR]: 24.81, 95% confidence interval [CI] [3.930, 156.702], P = 0.0002) and Autologous (OR: 6.43, 95% CI [1.156, 35.772], P = 0.0335) transfusions were independently associated with postoperative delirium.

CONCLUSION

Our study suggests that there may be an independent association between intraoperative autologous and allogenic blood transfusions and postoperative delirium after complex spinal fusion. Further studies are necessary to identify the physiological effect of blood transfusions to better overall patient care and reduce healthcare expenditures.

LEVEL OF EVIDENCE

3.

Storage injury and blood transfusions in trauma patients

PURPOSE OF REVIEW

The aim of the present review was to concisely summarize recent studies and current knowledge about effects of red blood cell storage injury in trauma patients.

RECENT FINDINGS

Despite a pathophysiological rationale for older packed red blood cells (PRBCs) being associated with adverse events in the host organism, recent large clinical trials failed to show negative effects of transfusion with older PRBCs on clinically relevant outcomes in mixed patient population. However, there is a lack of well-designed randomized controlled trials focusing on the effects of storage lesion of PRBCs in trauma patients.

SUMMARY

In the absence of specific evidence for trauma patients, we recommend to continue with a conservative transfusion regime and standard of care blood banking practice of using older PRBCs first.

Modernising Hip Fracture Anaesthesia

Hip fracture carries a 30-day mortality of around 8% in the United Kingdom. This figure has remained relatively unchanged despite modern developments in anaesthetic technique. These range from improvements in perioperative analgesia and mortality scoring systems, changes to intra-operative anaesthetic technique and strategies to reduce the requirement for blood transfusion. In this article, we review the current literature on the perioperative management of patients undergoing hip fracture surgery including some of the current controversies.