Effect of deep neuromuscular blockade on serum cytokines and postoperative delirium in elderly patients undergoing total hip replacement: A prospective single-blind randomised controlled trial

Association Between Neuromuscular Blockade and Its Reversal With Postoperative Delirium in Older Patients: A Hospital Registry Study

BACKGROUND

Nondepolarizing neuromuscular blocking agents (ND-NMBAs) are dose-dependently associated with residual paralysis, delayed recovery, and prolonged hospitalization, factors that can predispose patients to postoperative delirium. We hypothesized that neuromuscular blockade is associated with a higher risk of delirium after surgery, and that this can be mitigated by administration of reversal agents.

METHODS

In total, 53,772 adult hospitalized patients aged ≥60 years who underwent general anesthesia for noncardiac, nonneurosurgical, nontransplant procedures between 2008 and 2024 at a tertiary health care network in Massachusetts, were included. The exposure was the intraoperative administration of ND-NMBAs. The primary outcome was 7-day delirium, identified from nursing and physician charts using a keyword-based search strategy paired with manual chart review, Confusion Assessment Method assessments, and International Classification of Diseases (9th/10th Revision, Clinical Modification) diagnostic codes.

RESULTS

In total, 43,723 (81.3%) patients received neuromuscular blockade. Approximately 2259 (4.2%) patients developed delirium, 1884 (4.3%) with, and 375 (3.7%) without ND-NMBA administration. In adjusted analyses, administration of ND-NMBAs was dose-dependently associated with a higher risk of postoperative delirium (adjusted odds ratio [ORadj] 1.15; 95% confidence interval [CI], 1.01-1.31; P = .038 and 1.09; 95% CI, 1.06-1.12; P < .001 per each unit increase in the effective dose required to achieve a 95% twitch reduction). 38,143 (87.2%) patients who received ND-NMBAs also received a reversal agent, which was associated with a lower risk of impaired neuromuscular recovery (preextubation train-of-four ratio <95; ORadj 0.60; 95% CI, 0.49-0.74; P < .001) and delirium (ORadj 0.73; 95% CI, 0.64-0.83; P < .001), compared to no reversal. The adverse effect of ND-NMBAs on delirium risk was eliminated by reversal agent administration (ORadj 1.07; 95% CI, 0.94-1.23; P = .30 with and ORadj 1.52; 95% CI, 1.28-1.79; P < .001 without reversal agent administration). There was no association between administration of neostigmine, compared to sugammadex, with postoperative delirium (ORadj 0.91; 95% CI, 0.73-1.12; P = .36).

CONCLUSIONS

Neuromuscular blockade during general anesthesia is dose-dependently associated with a higher risk of postoperative delirium. The administration of reversal agents mitigates this risk and might help reduce the occurrence of delirium after surgery.

Comparing general and regional anesthesia in patients undergoing primary total hip arthroplasty: analysis of national health insurance data in Korea

Objectives

To compare the effects of general and regional anesthesia on clinical outcomes following primary total hip arthroplasty (THA).

Methods

This retrospective study using data from the Korean National Health Insurance Research Database included 1,522 patients who underwent THA under general anesthesia (n = 640) or regional anesthesia (n = 882) between 2002 and 2015. We compared the mortality and complication rates within 30 days after surgery.

Results

Prosthesis failure (1.56% vs. 0.45%, p = 0.025), admission to the intensive care unit (9.53 vs. 5.44%, p = 0.0023), and total cost (₩7,332,515 vs. ₩6,833,295, p < 0.0001) were higher in the general anesthesia group than in the regional anesthesia group. No significant differences were observed in mortality (0.94% vs. 0.57%, p = 0.54), transfusion rate (81.1% vs. 80.9%, p = 0.94), length of hospital stay (45 vs. 45 days, p = 0.23), or other complications between the groups. Similar results were observed in propensity-score matched analysis (n = 640 patients per group).

Conclusion

Our study showed that both anesthesia types resulted in comparable mortality and complication rates in patients who underwent THA, but the costs differed.

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

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

Characteristics associated with effectiveness in postoperative delirium research: a systematic review of randomised controlled trials with meta-regression and meta-analysis

BACKGROUND

Postoperative delirium remains prevalent despite extensive research through randomised trials aimed at reducing its incidence. Understanding trial characteristics associated with interventions' effectiveness facilitates data interpretation.

METHODS

Trial characteristics were extracted from eligible trials identified through two systematic literature searches. Multivariable meta-regression was used to investigate trial characteristics associated with effectiveness estimated using odds ratios. Meta-analysis was used to investigate pooled effectiveness.

RESULTS

We identified 201 eligible trials. Compared with China, trials from the USA/Canada (ratio of odds ratio, 1.89; 95% confidence interval, 1.45-2.45) and Europe/Australia/New Zealand (1.67; 1.29-2.18) had an 89% and 67% higher odds ratio, respectively, suggesting reduced effectiveness. The effectiveness was enhanced when the incidence of postoperative delirium increased (0.85; 0.79-0.92, per 10% increase). Trials with concerns related to deviations from intended interventions reported increased effectiveness compared with those at low risk (0.69; 0.53-0.90). Compared with usual care, certain interventions appeared to have reduced the incidence of postoperative delirium in low-risk trials with low-to-moderate certainty of evidence. However, these findings should be considered inconclusive because of challenges in grouping heterogeneous interventions, the limited number of eligible trials, the prevalence of small-scale studies, and potential publication bias.

CONCLUSIONS

The effectiveness of postoperative delirium trials varied based on the region of trial origin, the incidence of delirium, and the risk of bias. The limitations caution against drawing definitive conclusions from different bodies of evidence. These findings highlight the imperative need to improve the quality of research on a global scale.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO (CRD42023413984).

Update of the European Society of Anaesthesiology and Intensive Care Medicine evidence-based and consensus-based guideline on postoperative delirium in adult patients

Postoperative delirium (POD) remains a common, dangerous and resource-consuming adverse event but is often preventable. The whole peri-operative team can play a key role in its management. This update to the 2017 ESAIC Guideline on the prevention of POD is evidence-based and consensus-based and considers the literature between 01 April 2015, and 28 February 2022. The search terms of the broad literature search were identical to those used in the first version of the guideline published in 2017. POD was defined in accordance with the DSM-5 criteria. POD had to be measured with a validated POD screening tool, at least once per day for at least 3 days starting in the recovery room or postanaesthesia care unit on the day of surgery or, at latest, on postoperative day 1. Recent literature confirmed the pathogenic role of surgery-induced inflammation, and this concept reinforces the positive role of multicomponent strategies aimed to reduce the surgical stress response. Although some putative precipitating risk factors are not modifiable (length of surgery, surgical site), others (such as depth of anaesthesia, appropriate analgesia and haemodynamic stability) are under the control of the anaesthesiologists. Multicomponent preoperative, intra-operative and postoperative preventive measures showed potential to reduce the incidence and duration of POD, confirming the pivotal role of a comprehensive and team-based approach to improve patients' clinical and functional status.

Deep versus moderate neuromuscular blockade during total hip arthroplasty to improve postoperative quality of recovery and immune function: protocol for a randomised controlled study

INTRODUCTION

There is accumulating evidence that deep neuromuscular blockade (NMB) improves intraoperative surgical conditions during laparoscopic surgery. Studies investigating the effects of deep NMB in open surgery are scarce. In theory, by limiting surgical damage through deeper muscle relaxation, postoperative inflammation and concomitant immune suppression can be reduced. Therefore, this study will investigate the effects of deep NMB during total hip arthroplasty, which demands a relatively large exposure of the hip joint through and in between muscles.

METHODS AND ANALYSIS

This study is a monocentre blinded randomised controlled trial in 100 patients undergoing total hip arthroplasty under general anaesthesia. Patients will be randomised in a 1:1 fashion to an intervention group of intraoperative deep NMB (a post-tetanic count of 1-2) or a control group receiving moderate NMB (a train-of-four count of 1-2). NMB will be achieved by continuous or bolus administration of rocuronium, respectively. The primary endpoint is the quality of recovery at postoperative day 1 measured by the Quality of Recovery-40 Questionnaire, analysed by Analysis of Variance. The secondary endpoint is postoperative innate immune function, measured by ex vivo production capacity of tumour necrosis factor and interleukin-1β on endotoxin stimulation of whole blood.

ETHICS AND DISSEMINATION

Ethical approval for this study was granted by the Medical Ethics Committee 'METC Oost-Nederland' (reference number 2022-15754). Informed consent will be obtained prior to study participation. Study results will be published in an international peer-reviewed journal.

TRIAL REGISTRATION NUMBERS

ClinicalTrials.gov Registry (NCT05562999) and EudraCT Registry (2022-002451-19).

Subjective cognitive decline may mediate the occurrence of postoperative delirium by P-tau undergoing total hip replacement: The PNDABLE study

OBJECTIVE

We again investigated the relationship between subjective cognitive decline (SCD) and postoperative delirium (POD) with a larger sample queue. We also determined whether SCD could cause the occurrence of POD through cerebrospinal fluid (CSF) biomarkers.

METHODS

A prospective, observational cohort study was implemented in the Qingdao Municipal Hospital Affiliated with Qingdao University. This study recruited 1,471 qualified patients affiliated with the Perioperative Neurocognitive Disorder And Biomarker Lifestyle (PNDABLE) study scheduled for total hip replacement under combined spinal and epidural anesthesia from June 2020 to May 2022. The Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA) were used to assess the cognitive level of the patients the day before surgery. Pittsburgh sleeps quality index (PSQI) scale was used to assess sleep status. Patients were divided into the SCD group and the non-SCD (NSCD) group based on the Subjective Cognitive Decline Scale (SCDS). CSF was collected after a successful spinal-epidural combined puncture, and amyloid-β40 (Aβ40), amyloid-β42 (Aβ42), total tau (T-tau), and phosphorylated tau (P-Tau) in CSF were analyzed by enzyme-linked immunosorbent assays. After the surgery, the incidence of POD was determined by the Confusion Assessment Scale (CAM), and Memorial Delirium Assessment Scale (MDAS) score was used to determine the severity of POD. Logistic regression and sensitivity analyses were performed to determine the relationship between CSF biomarkers, SCD, and POD. The mediating effect was used to analyze the function of specific CSF biomarkers in the relationship between SCD and POD. The risk factors of SCD were also separately verified by logistic regression and sensitivity analysis models.

RESULTS

The total incidence rate of POD was 19.60% (n = 225/1148), which was 29.3% (n = 120/409) in the SCD group and 14.2% (n = 105/739) in the NSCD group. We comprehensively considered the effect of covariates such as age, hypertension, and diabetes. Multivariate logistic regression analysis showed that SCD (OR = 1.467, 95%CI: 1.015-2.120, p = 0.042) and P-tau (OR = 1.046, 95%CI: 1.028-1.063, p < 0.001) were risk factors for POD. The sensitivity analysis results were consistent with the above results. Mediation analysis showed that the relationship between SCD and POD was partially mediated by P-tau, which accounted for 31.25% (P-tau, IE = 4.279 × 10-2, p < 0.001). For SCD, the results of logistic regression analysis models showed that age (OR = 1.035, 95% CI: 1.020-1.049, p < 0.001), higher preoperative PSQI score (OR = 1.047, 95%CI: 1.014-1.080, p = 0.005), and P-tau (OR = 1.015, 95%CI: 1.002-1.028, p = 0.021) were risk factors for SCD, and subsequent sensitivity analysis confirmed this result after adjustment for ASA grade, height, and weight.

CONCLUSION

Patients with SCD are more likely to develop POD undergoing total hip replacement, and SCD can mediate the occurrence of POD via P-tau.

CLINICAL TRIAL REGISTRATION

This study was registered at China Clinical Trial Registry (Chictr2000033439).

Effects of Lumbar Plexus Block Combined with Infiltration Anesthesia on Anesthesia Comfort Scores and Stress Responses in Elderly Patients Undergoing Hip Replacement

Objective. To investigate the effects of lumbar plexus block combined with infiltration anesthesia on anesthesia comfort scores and stress responses in elderly patients undergoing hip replacement. Methods. The materials of 100 elderly patients undergoing hip replacement who were treated in our hospital (January 2020-January 2021) were retrospectively analyzed, and they were equalized into the experimental group ( $n=50$ ) and control group ( $n=50$ ) according to the anesthesia methods. The experimental group received lumbar plexus block combined with infiltration anesthesia, and the control group received combined spinal-epidural anesthesia combined with infiltration anesthesia. The patients’ anesthesia comfort scores, stress responses, and postoperative pain indexes were compared between the two groups. Results. Compared with the control group, the experimental group achieved much lower scores of mood change, shivering response, and traction reaction ( $P<0.001$ ), indicating that the anesthesia comfort in the experimental group was higher. Compared with the control group, the experimental group had much better perioperative stress response indexes ( $P<0.05$ ) and eminently lower pain scores at 12 and 24 hours after surgery ( $P<0.05$ ). Conclusion. Lumbar plexus block combined with infiltration anesthesia can relieve the stress responses and postoperative pain of elderly patients undergoing hip replacement and increase their anesthesia comfort. Therefore, this anesthesia method is translational in clinic.

The effects of moderate neuromuscular blockade combined with transverse abdominal plane block on surgical space conditions during laparoscopic colorectal surgery: a randomized clinical study

Background

Deep neuromuscular blockade may be beneficial on surgical space conditions during laparoscopic surgery. The effects of moderate neuromuscular blockade combined with transverse abdominal plane block (TAPB) on surgical space conditions during laparoscopic surgery have not been described. This work investigated whether the above combination is associated with similar surgical space conditions to those of deep neuromuscular blockade.

Methods

Eighty patients undergoing elective laparoscopic surgery for colorectal cancer were randomly divided into two groups. The intervention group was treated with moderate neuromuscular blockade (train-of-four (TOF) count between 1 and 3) combined with TAPB (M group), while the control group was treated with deep neuromuscular blockade (D group), with a TOF count of 0 and a post-tetanic count (PTC) ≥1. Both groups received the same anesthesia management. The distance between the sacral promontory and the umbilical skin during the operation was compared between the two groups. The surgeon scored the surgical space conditions according to a five-point ordinal scale. Patients’ pain scores were evaluated 8 h after the operation.

Results

The distance from the sacral promontory to the umbilical skin after pneumoperitoneum was similar between the D group and M group (16.03 ± 2.17 cm versus 16.37 ± 2.78 cm; P = 0.544). The 95% confidence intervals of the difference in the distance from the sacral promontory to the umbilical skin between the two groups were − 1.45–0.77 cm. According to the preset non-inferior standard of 1.5 cm, (− 1.45, ∞) completely fell within (− 1.50, ∞), and the non-inferior effect test was qualified. No significant difference was found in the surgical rating score between the two groups. The dosage of rocuronium in the group D was significantly higher than that in the group M (P < 0.01). The M group had significantly lower pain scores than the D group 8 h after the operation (P < 0.05).

Conclusions

Moderate neuromuscular blockade combined with TAPB applied to laparoscopic colorectal cancer surgery can provide surgical space conditions similar to those of deep neuromuscular blockade. In addition, it reduces the use of muscle relaxants, relieves postoperative pain within 4 h after operation, and shorten the extubation time and stay in PACU when neostigmine was used as muscle relaxant antagonist.

Trial registration

chictr.org.cn (ChiCTR2000034621), registered on July 12, 2020.

Subjective Cognitive Decline May Be Associated With Post-operative Delirium in Patients Undergoing Total Hip Replacement: The PNDABLE Study

Objective: Subjective cognitive decline (SCD) is associated with an increased risk of clinical cognitive disorders. Post-operative delirium (POD) is a common complication after total hip replacement. We aimed to investigate the relationship between SCD and POD in patients undergoing total hip replacement. Methods: Our study recruited 214 cognitively intact individuals from the Perioperative Neurocognitive Disorder And Biomarker Lifestyle (PNDABLE) study in the final analysis. SCD was diagnosed with Subjective Cognitive Decline Scale (SCDS), Mini-Mental State Examination (MMSE), and Montreal Cognitive Assessment (MoCA). The incidence of POD was evaluated by using Confusion Assessment Method (CAM), and POD severity was measured by using the Memorial Delirium Assessment Scale (MDAS). Preoperative cerebrospinal fluid (CSF) Aβ40, Aβ42, T-tau, and P-tau levels were measured by enzyme-linked immune-sorbent assay (ELISA). Results: Overall, the incidence of POD was 26.64% (57/214), including 32.43% (36/111) in the SCD group and 20.39% (21/103) in the NC group. With the increase of age, the incidence of POD in all age groups increased (P < 0.05). Logistic regression analysis showed that after adjusting for SCD, Aβ42, Aβ40, P-tau, and T-tau, SCD (OR 2.32, CI 1.18-4.55, P = 0.01) and the increased CSF level of P-tau (OR 1.04, CI 1.01-1.06, P < 0.001) were risk factors for POD, while the level of aβ42 (OR 0.99, CI 0.99-1.00, P < 0.001) was a protective factor for POD. Conclusion: SCD is one of the preoperative risk factors for POD. Clinical Trial Registration: This study was registered at China Clinical Trial Registry (Chictr200033439).