Postoperative Delirium after Dexmedetomidine versus Propofol Sedation in Healthy Older Adults Undergoing Orthopedic Lower Limb Surgery with Spinal Anesthesia: A Randomized Controlled Trial

Pharmacological Prevention of Postoperative Delirium in Adults: A Review of Recent Literature

PURPOSE OF REVIEW

Postoperative delirium (POD) is a common complication that has important implications for surgical patients, often leading to both short- and long-term cognitive deficits, worse outcomes, and increased healthcare costs. Given these implications, there may be a benefit in reducing the incidence of POD. Pharmacologic interventions may have the potential to reduce the risk of a patient developing POD.

RECENT FINDINGS

Recently studied therapies include dexmedetomidine, propofol, haloperidol, ketamine, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, acetaminophen, melatonin/ramelteon, corticosteroids, midazolam, physostigmine, and neostigmine. In addition, the implementation of regional anesthesia and reduction of overall anesthetic depth have been examined. Of these therapies, dexmedetomidine has been studied the most and has the most supporting evidence for prevention of POD, but current studies lack clarity on optimal dosing and timing of dexmedetomidine administration. Acetaminophen, corticosteroids, and melatonin/ramelteon are other plausible medications that have potential for reducing POD incidence, but they all require further investigation. Reduction of anesthetic depth and regional anesthetics are options for anesthetic management that show promise but still lack enough supporting evidence in recent literature to receive a strong recommendation. Future research should focus on identifying optimal strategies for the implementation of the pharmacological options listed, including doses and timing of administration. Attention should be given to dexmedetomidine given its promise demonstrated by recent literature.

Post-operative delirium in different age groups and subtypes: a systematic review of case reports

Aims

To explore the clinical presentations and outcomes among different ages and subtypes of post-operative delirium patients.

Design

Systematic review of Published Cases.

Methods and data sources

We comprehensively searched PubMed, EMBASE, and MEDLINE for published case reports of post-operative delirium up to April 2023. The systematic review has been registered with PROSPERO. Two researchers independently conducted unblinded reviews of the full-text articles.

Results

This study included 116 patients with post-operative delirium. Compared to post-operative delirium patients aged 65 and above, those between 18 and 65 years old have lower rates of a history of hypertension, cardiovascular disease and urinary system disorder comorbidities, as well as higher usage rates of fentanyl analogs and lorazepam. Additionally, these patients exhibit lower incidences of anemia and renal failure, along with a lower mortality rate. Compared to post-operative delirium patients aged 65 and above, those under 18 years old have a higher rate of fentanyl analog usage and a higher incidence of post-operative delirium following neurological surgeries. Among the hypoactive, hyperactive, and mixed subtypes, the reasons for surgery, such as cardiovascular diseases, reproductive system diseases, and neurological disorders, significantly varied among these three subtypes. Furthermore, substance abuse history and medication usage patterns also significantly varied among these three subtypes.

Conclusions

Our investigation has revealed noteworthy insights into post-operative delirium in different patient populations. Notably, age emerged as a pivotal factor. Compared to elderly patients (≥65 years), those aged 18 to 65 demonstrate better prognosis. Additionally, patients younger than 18 years with post-operative delirium have a higher incidence of delirium following neurosurgical procedures compared to those elderly patients. Additionally, a strong association was found between a history of substance abuse and hyperactive delirium. Variations in drug use patterns were observed across different subtypes. Importantly, post-operative delirium patients younger than 18 years, as well as those aged 18 to 65 with mixed-subtype delirium, exhibited similar high mortality rates as elderly patients. This underscores the need for increased attention to post-operative delirium patients under 65 and highlights the necessity of rapid identification and early intervention for these populations at risk of poor outcomes.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023473383, Identifier [Registration ID: CRD 42023473383].

Efficacy and Safety of Dexmedetomidine in the Prone Position in Elderly Patients with Pneumonia: A Prospective, Double-Blind, Randomized Controlled Study

PURPOSE

We aimed to identify a safe and effective method to assist older adults with pneumonia in tolerating the prone position for a longer duration.

METHODS

This was a randomized, controlled, double-blinded study performed at the Shanghai Fourth People's Hospital. Eighty patients with pneumonia aged ≥ 65 years were included. The patients were able to spontaneous breath in the prone position and were administered intravenous dexmedetomidine or an isotonic sodium chloride solution. The cumulative daily durations of prone positioning for all patients in the two groups were recorded. The primary outcome was the percentage of patients who completed ≥ 9 h/day in the prone position. The secondary outcomes included the incidence of complications in the prone position and patient outcomes.

RESULTS

Eighty patients were included (average age: 79.6 ± 8.9 years). The percentage of patients who completed ≥ 9 h/day in the prone position was significantly higher in the dexmedetomidine group than in the placebo group (P = 0.011). The percentage of patients who completed ≥ 12 h/day in the prone position was also significantly greater in the dexmedetomidine group than in the placebo group (P = 0.008). There were no significant differences in other variables between the two groups.

CONCLUSIONS

The results of this study demonstrate that intravenous dexmedetomidine injection can significantly prolong the duration of spontaneous breathing in the prone position in elderly pneumonia patients without obvious adverse events. We provide a safe and effective method to help patients with pneumonia, especially those with delirium or cognitive impairment, who cannot tolerate the length of time needed for spontaneous breathing in the prone position to be effective.

TRIAL REGISTRATION

The study was registered with the Chinese Clinical Trial Center (registration number: ChiCRT2300067383) on 2023-01-05.

The effect of perioperative dexmedetomidine on postoperative delirium in adult patients undergoing cardiac surgery with cardiopulmonary bypass: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Dexmedetomidine is considered to have neuroprotective effects and may reduce postoperative delirium in both cardiac and major non-cardiac surgeries. Compared with non-cardiac surgery, the delirium incidence is extremely high after cardiac surgery, which could be caused by neuroinflammation induced by surgical stress and CPB. Thus, it is essential to explore the potential benefits of dexmedetomidine on the incidence of delirium in cardiac surgery under CPB.

METHODS

Randomized controlled trials studying the effect of perioperative dexmedetomidine on the delirium incidence in adult patients undergoing cardiac surgery with CPB were considered to be eligible. Data collection was conducted by two reviewers independently. The pre-specified outcome of interest is delirium incidence. RoB 2 was used to perform risk of bias assessment by two reviewers independently. The random effects model and Mantel-Haenszel statistical method were selected to pool effect sizes for each study.

RESULTS

PubMed, Embase, Cochrane Library, and Web of Science were systematically searched from inception to June 28, 2023. Sixteen studies including 3381 participants were included in our systematic review and meta-analysis. Perioperative dexmedetomidine reduced the incidence of postoperative delirium in patients undergoing cardiac surgery with CPB compared with the other sedatives, placebo, or normal saline (RR 0.57; 95% CI 0.41-0.79; P = 0.0009; I2 = 61%).

CONCLUSIONS

Perioperative administration of dexmedetomidine could reduce the postoperative delirium occurrence in adult patients undergoing cardiac surgery with CPB. However, there is relatively significant heterogeneity among the studies. And the included studies comprise many early-stage small sample trials, which may lead to an overestimation of the beneficial effects. It is necessary to design the large-scale RCTs to further confirm the potential benefits of dexmedetomidine in cardiac surgery with CPB.

REGISTRATION NUMBER

CRD42023452410.

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).

Retrospective comparison of the effects of remimazolam and dexmedetomidine on postoperative delirium in elderly patients undergoing orthopedic surgery of the lower extremities under spinal anesthesia

PURPOSE

Remimazolam is often used for perioperative sedation due to its rapid onset and offset. However, the possible association between remimazolam and postoperative delirium (POD) remains undetermined. The present study evaluated whether remimazolam increased the incidence of POD compared with dexmedetomidine in elderly patients undergoing orthopedic surgery of the lower extremities.

METHODS

This retrospective study included patients aged ≥ 65 years who had undergone orthopedic surgery of the lower extremities under spinal anesthesia from January 2020 to November 2022 and were sedated with continuous intravenous infusion of dexmedetomidine or remimazolam. The incidence of POD was assessed through a validated comprehensive review process of each patient's medical records. The effect of remimazolam on the occurrence of POD compared with dexmedetomidine was evaluated by propensity score weighted multivariable logistic models.

RESULTS

A total of 447 patients were included in the final analysis. The crude incidence of POD within 3 days after surgery was 7.5% (17/226) in the dexmedetomidine group and 11.8% (26/221) in the remimazolam group, increasing to 9.7% (22/226) and 15.8% (35/221), respectively (p = 0.073), within 5 days. The multivariable models showed that, compared with dexmedetomidine, intraoperative sedation with remimazolam significantly increased the occurrence of POD within 3 days (odds ratio [OR] 2.21, 95% confidence interval [CI] 1.31 to 3.82, p = 0.003) and 5 days (OR 2.10, 95% CI 1.32 to 3.40, p = 0.002).

CONCLUSION

Compared with dexmedetomidine, remimazolam infusion may be associated with a higher risk of POD in elderly patients undergoing orthopedic surgery of the lower extremities under spinal anesthesia.

Effects of dexmedetomidine on early postoperative cognitive function and postoperative inflammatory response: a systematic review and network meta-analysis

Background

Dexmedetomidine (DEX) has demonstrated potential as an effective agent for enhancing early postoperative cognitive function. However, there is ongoing debate regarding its optimal dosage and impact on early postoperative inflammatory response. This study aimed to assess and prioritize the effects of varying doses of DEX on early postoperative cognitive function and inflammatory response, in order to identify the most effective intervention dosage.

Methods

Randomised controlled trials (RCTs) and retrospective cohort studies (RCS) from PubMed, Embase, and Cochrane Library up to January 28, 2024, were included. The Mini-Mental State Examination (MMSE) was utilized to assess the impact of varying doses of DEX on cognitive function during the early postoperative period as the primary outcome, peripheral blood levels of IL-6 and TNF-α were considered as secondary outcomes. Meta-analysis and Bayesian Network Meta-Analysis (NMA) were conducted using R. Funnel plots were generated using Stata 15.0.

Results

A total of 29 studies involving 2,807 patients and 25 different doses of DEX were included. DEX was given at a loading dose of 0.3-1.0 μg/kg followed by a maintenance dose of 0.1-0.5 μg/kg/h, or at a uniform intraoperative dose of 0.4-0.7 μg/kg/h. Network meta-analysis revealed most doses of DEX were significantly more effective than normal saline (NS) in improving postoperative MMSE scores (on days 1, 3, and 7) and lowering IL-6 and TNF-α levels. Probability results showed that a 1 μg/kg loading dose followed by a 0.6 μg/kg/h maintenance dose was the best dosing regimen for improving MMSE scores on postoperative days 1 (97.3%), 3 (100%), and 7 (99.9%), as well as for reducing postoperative blood IL-6 levels (1.3%). On the other hand, 0.3 μg/kg followed by 0.2 μg/kg/h was the optimal dosing regimen for reducing postoperative blood TNF-α levels (6.6%).

Conclusion

Compared with NS, intraoperative intravenous DEX improved early postoperative cognitive function and postoperative inflammatory response in patients undergoing elective surgery. In particular, a 1 μg/kg loading dose and a 0.6 μg/kg/h maintenance dose resulted in the best improvement in postoperative MMSE scores and blood IL-6 levels, while a 0.3 μg/kg loading dose followed by a 0.2 μg/kg/h maintenance dose is the optimal regimen for lowering postoperative blood TNF-α levels.Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=433932, identifier CRD42023433932.

Perioperative dexmedetomidine-induced delirium in a patient with schizophrenia: a case report

BACKGROUND

Dexmedetomidine is a selective α2 receptor agonist with sedative, analgesic, anxiolytic, and anti-sympathetic effects. Dexmedetomidine is widely used for various surgical procedures performed under general anaesthesia and sedation in the intensive care unit. Dexmedetomidine was known to relieve or improve the symptoms of delirium. Schizophrenia is a common psychiatric disease, and the number of surgical patients with schizophrenia is increasing gradually. Dexmedetomidine-induced delirium in patients with schizophrenia is a particular case.

CASE PRESENTATION

This patient was a 75-year-old woman (height: 156 cm; weight: 60 kg) with a 5-year history of schizophrenia. Her schizophrenia was well controlled with medications. She was scheduled for open reduction and internal fixation for a patellar fracture. Spinal anaesthesia was administered for surgery, and dexmedetomidine was administered intravenously to maintain sedation. The patient became delirious half an hour after the surgery began. The intravenous infusion of dexmedetomidine was discontinued immediately, intravenous propofol was subsequently administered, and the patient stopped experiencing dysphoria and fell asleep. After surgery, the patient stopped using propofol and recovered smoothly. She was transferred back to the general ward and was discharged from the hospital without any abnormal conditions on the 9th day after surgery.

CONCLUSIONS

To the best of our knowledge, this is the first report of a patient with schizophrenia who developed delirium during the infusion of a normal dose of dexmedetomidine without an intravenous injection of any other sedative. The exact mechanism causing dexmedetomidine-induced delirium remains unclear, and this adverse reaction is rare and easy to ignore. Clinicians and pharmacists should be vigilant in identifying this condition.

Association of postoperative delirium with hypotension in critically ill patients after cardiac surgery: a prospective observational study

BACKGROUND

Postoperative delirium (POD), an acute and variable disturbance in cognitive function, is an intricate and elusive phenomenon that occurs after cardiac surgery. Despite progress in surgical techniques and perioperative management, POD remains a formidable challenge, imposing a significant burden on patients, caregivers, and healthcare systems.

METHODS

This prospective observational study involved 307 patients who underwent cardiac surgery. Data on the occurrence of delirium, clinical parameters, and postoperative characteristics were collected. A multivariate analysis was performed to assess the relationship between POH and POD.

RESULTS

Sixty-one patients (21%) developed delirium, with an average onset of approximately 5 days postoperatively and a duration of approximately 6 days. On multivariate analysis, POH was significantly associated with POD, and the adjusted odds ratios indicated that patients with POH were more likely to develop delirium (OR, 5.61; p = 0.006). Advanced age (OR, 1.11; p = 0.002), emergency surgery (OR, 8.31; p = 0.001), and on-pump coronary artery bypass grafting were identified as risk factors of POD. Patients who developed delirium were typically older, more likely to be male, and had higher morbidity rates than those who did not.

CONCLUSION

POH is significantly associated with delirium in critically ill patients after cardiac surgery. Surgical complexity and advanced age contribute to the risk of developing POD and poor postoperative outcomes.

Electroencephalographic guided propofol-remifentanil TCI anesthesia with and without dexmedetomidine in a geriatric population: electroencephalographic signatures and clinical evaluation

Elderly and multimorbid patients are at high risk for developing unfavorable postoperative neurocognitive outcomes; however, well-adjusted and EEG-guided anesthesia may help titrate anesthesia and improve postoperative outcomes. Over the last decade, dexmedetomidine has been increasingly used as an adjunct in the perioperative setting. Its synergistic effect with propofol decreases the dose of propofol needed to induce and maintain general anesthesia. In this pilot study, we evaluate two highly standardized anesthetic regimens for their potential to prevent burst suppression and postoperative neurocognitive dysfunction in a high-risk population. Prospective, randomized clinical trial with non-blinded intervention. Operating room and post anesthesia care unit at Hospital Base San José, Osorno/Universidad Austral, Valdivia, Chile. 23 patients with scheduled non-neurologic, non-cardiac surgeries with age > 69 years and a planned intervention time > 60 min. Patients were randomly assigned to receive either a propofol-remifentanil based anesthesia or an anesthetic regimen with dexmedetomidine-propofol-remifentanil. All patients underwent a slow titrated induction, followed by a target controlled infusion (TCI) of propofol and remifentanil (n = 10) or propofol, remifentanil and continuous dexmedetomidine infusion (n = 13). We compared the perioperative EEG signatures, drug-induced changes, and neurocognitive outcomes between two anesthetic regimens in geriatric patients. We conducted a pre- and postoperative Montreal Cognitive Assessment (MoCa) test and measured the level of alertness postoperatively using a sedation agitation scale to assess neurocognitive status. During slow induction, maintenance, and emergence, burst suppression was not observed in either group; however, EEG signatures differed significantly between the two groups. In general, EEG activity in the propofol group was dominated by faster rhythms than in the dexmedetomidine group. Time to responsiveness was not significantly different between the two groups (p = 0.352). Finally, no significant differences were found in postoperative cognitive outcomes evaluated by the MoCa test nor sedation agitation scale up to one hour after extubation. This pilot study demonstrates that the two proposed anesthetic regimens can be safely used to slowly induce anesthesia and avoid EEG burst suppression patterns. Despite the patients being elderly and at high risk, we did not observe postoperative neurocognitive deficits. The reduced alpha power in the dexmedetomidine-treated group was not associated with adverse neurocognitive outcomes.

Mapping Theme Trends and Research Frontiers in Dexmedetomidine Over Past Decade: A Bibliometric Analysis

Background

Dexmedetomidine, an α2-adrenergic receptor (α2-AR) agonist, is extensively used in clinical and animal studies owing to its sedative, analgesic, and anxiolytic effects. The diverse range of research domains associated with dexmedetomidine poses challenges in defining pivotal research directions. Therefore, this study aimed to conduct a qualitative and quantitative bibliometric study in the field of dexmedetomidine over the past decade to establish current research trends and emerging frontiers.

Methods

Relevant publications in the field of dexmedetomidine between 2014 and 2023 were extracted from the Web of Science Core Collection database. The bibliometric analysis, incorporating statistical and visual analyses, was conducted using CiteSpace (6.1.R6) and R (4.3.1).

Results

The present study encompassed a total of 5,482 publications, exhibiting a consistent upward trend over the past decade. The United States and its institutions had the highest centrality. Ji, Fuhai, and Ebert, Thomas J. were identified as the most productive author and the most cited author, respectively. As anticipated, the most cited journal was Anesthesiology. Moreover, cluster analysis of cited references and co-occurrence of keywords revealed that recent studies were primarily focused on sedation, delirium, and opioid-free anesthesia. Finally, a timeline view of keywords clusters and keywords burst demonstrated that primary research frontiers were stress response, neuroinflammation, delirium, opioid-free anesthesia, peripheral nerve block, and complications.

Conclusion

Current research trends and directions are focused on sedation, delirium, and opioid-free anesthesia, as evidenced by our results. The frontier of future research is anticipated to encompass basic investigations into dexmedetomidine, including stress response and neuroinflammation, as well as clinical studies focusing on delirium, opioid-free anesthesia, peripheral nerve block, and associated complications.

Combination of Creatinine with Inflammatory Biomarkers (PCT, CRP, hsCRP) for Predicting Postoperative ICU Admissions for Elderly Patients

INTRODUCTION

The number of elderly patients who require surgery as their primary treatment has increased rapidly in recent years. Among 300 million people globally who underwent surgery every year, patients aged 65 years and over accounted for more than 30% of cases. Despite medical advances, older patients remain at higher risk of postoperative complications. Early diagnosis and effective prediction are essential requirements for preventing serious postoperative complications. In this study, we aim to provide new biomarker combinations to predict the incidence of postoperative intensive care unit (ICU) admissions > 24 h in elderly patients.

METHODS

This investigation was conducted as a nested case-control study, incorporating 413 participants aged ≥ 65 years who underwent non-cardiac, non-urological elective surgeries. These individuals underwent a 30-day postoperative follow-up. Before surgery, peripheral venous blood was collected for analyzing serum creatinine (Scr), procalcitonin (PCT), C-reactive protein (CRP), and high-sensitivity CRP (hsCRP). The efficacy of these biomarkers in predicting postoperative complications was evaluated using receiver operating characteristic (ROC) curve analysis and area under the curve (AUC) values.

RESULTS

Postoperatively, 10 patients (2.42%) required ICU admission. Regarding ICU admissions, the AUCs with 95% confidence intervals (CIs) for the biomarker combinations of Scr × PCT and Scr × CRP were 0.750 (0.655-0.845, P = 0.007) and 0.724 (0.567-0.882, P = 0.015), respectively. Furthermore, cardiovascular events were observed in 14 patients (3.39%). The AUC with a 95% CI for the combination of Scr × CRP in predicting cardiovascular events was 0.688 (0.560-0.817, P = 0.017).

CONCLUSION

The innovative combinations of biomarkers (Scr × PCT and Scr × CRP) demonstrated efficacy as predictors for postoperative ICU admissions in elderly patients. Additionally, the Scr × CRP also had a moderate predictive value for postoperative cardiovascular events.

TRIAL REGISTRATION

China Clinical Trial Registry, ChiCTR1900026223.

Development and validation of delirium prediction models for noncardiac surgery patients

STUDY OBJECTIVE

Postoperative delirium is associated with morbidity and mortality, and its incidence varies widely. Using known predisposing and precipitating factors, we sought to develop postoperative delirium prediction models for noncardiac surgical patients.

DESIGN

Retrospective prediction model study.

SETTING

Major quaternary medical center.

PATIENTS

Our January 2016 to June 2020 training dataset included 51,677 patients of whom 2795 patients had delirium. Our July 2020 to January 2022 validation dataset included 14,438 patients of whom 912 patients had delirium.

INTERVENTIONS

None.

MEASUREMENTS

We trained and validated two static prediction models and one dynamic delirium prediction model. For the static models, we used random survival forests and traditional Cox proportional hazard models to predict postoperative delirium from preoperative variables, or from a combination of preoperative and intraoperative variables. We also used landmark modeling to dynamically predict postoperative delirium using preoperative, intraoperative, and postoperative variables before onset of delirium.

MAIN RESULTS

In the validation analyses, the static random forest model had a c-statistic of 0.81 (95% CI: 0.79, 0.82) and a Brier score of 0.04 with preoperative variables only, and a c-statistic of 0.86 (95% CI: 0.84, 0.87) and a Brier score of 0.04 when preoperative and intraoperative variables were combined. The corresponding Cox models had similar discrimination metrics with slightly better calibration. The dynamic model - using all available data, i.e., preoperative, intraoperative and postoperative data - had an overall c-index of 0.84 (95% CI: 0.83, 0.85).

CONCLUSIONS

Using preoperative and intraoperative variables, simple static models performed as well as a dynamic delirium prediction model that also included postoperative variables. Baseline predisposing factors thus appear to contribute far more to delirium after noncardiac surgery than intraoperative or postoperative variables. Improved postoperative data capture may help improve delirium prediction and should be evaluated in future studies.

Intravenous infusion of dexmedetomidine during the surgery to prevent postoperative delirium and postoperative cognitive dysfunction undergoing non-cardiac surgery: a meta-analysis of randomized controlled trials

BACKGROUND

Dexmedetomidine plays a pivotal role in mitigating postoperative delirium and cognitive dysfunction while enhancing the overall quality of life among surgical patients. Nevertheless, the influence of dexmedetomidine on such complications in various anaesthesia techniques remains inadequately explored. As such, in the present study, a meta-analysis was conducted to comprehensively evaluate its effects on postoperative delirium and cognitive dysfunction.

METHODS

A number of databases were searched for randomised controlled trials comparing intravenous dexmedetomidine to other interventions in preventing postoperative delirium and cognitive dysfunction in non-cardiac and non-neurosurgical patients. These databases included PubMed, Embase, and Cochrane Library. Statistical analysis and graphing were performed using Review Manager, STATA, the second version of the Cochrane risk-of-bias tool for randomised controlled trials, and GRADE profiler.

MAIN RESULTS

This meta-analysis comprised a total of 24 randomised controlled trials, including 20 trials assessing postoperative delirium and 6 trials assessing postoperative cognitive dysfunction. Across these 24 studies, a statistically significant positive association was observed between intravenous administration of dexmedetomidine and a reduced incidence of postoperative delirium (RR: 0.55; 95% CI 0.47 to 0.64, p < 0.00001, I2 = 2%) and postoperative cognitive dysfunction (RR: 0.60; 95% CI 0.38 to 0.96, p = 0.03, I2 = 60%). Subgroup analysis did not reveal a significant difference in the incidence of postoperative delirium between the general anaesthesia and non-general anaesthesia groups, but a significant difference was observed in the incidence of postoperative cognitive dysfunction. Nonetheless, when the data were pooled, it was evident that the utilisation of dexmedetomidine was associated with an increased incidence of hypotension (RR: 1.42; 95% CI 1.08 to 1.86, p = 0.01, I2 = 0%) and bradycardia (RR: 1.66; 95% CI 1.23 to 2.26, p = 0.001, I2 = 0%) compared with other interventions. However, there was no significantly higher occurrence of hypertension in the DEX groups (RR = 1.35, 95% CI 0.81-2.24, p = 0.25, I2 = 0%).

CONCLUSION

Compared with other interventions, intravenous dexmedetomidine infusion during non-cardiac and non-neurosurgical procedures may significantly reduce the risk of postoperative delirium and cognitive dysfunction. The results of subgroup analysis reveal a consistent preventive effect on postoperative delirium in both general and non-general anaesthesia groups. Meanwhile, continuous infusion during general anaesthesia was more effective in reducing the risk of cognitive dysfunction. Despite such findings, hypotension and bradycardia were more frequent in patients who received dexmedetomidine during surgery.

Association of Intravenous Neostigmine and Anticholinergics or Sugammadex with Postoperative Delirium: A Retrospective Cohort Study

BACKGROUND

Administration of cholinesterase inhibitors in combination with anticholinergic drugs for reversal of neuromuscular blocks may precipitate delirium through impairment of central cholinergic transmission, which could be avoided by using sugammadex. Therefore, we tested the primary hypothesis that postoperative delirium is less common when neuromuscular block is reversed with sugammadex than with neostigmine combined with glycopyrrolate or atropine.

METHODS

We conducted a single-center retrospective cohort study, analyzing all adult patients having general anesthesia for noncardiac surgery who received neostigmine or sugammadex from January 2016 to March 2022. Inverse propensity score weighting and propensity score calibration were used to adjust for appropriate confounders. Our primary outcome was presence of delirium within the first 4 days after surgery, defined as at least 1 positive brief Confusion Assessment Method (bCAM) screening. The secondary outcome was the presence of early delirium within 24 hours of surgery.

RESULTS

Among 49,468 cases in our analysis, 6881 received sugammadex and 42,587 received neostigmine. After propensity weighting, the incidence of delirium was 1.09% in the sugammadex group and 0.82% in the neostigmine group. The odds of postoperative delirium did not differ between the sugammadex and neostigmine groups, with an estimated odds ratio (95% confidence interval) of 1.33 (0.91-1.95), P = .147. A sensitivity analysis restricted to only include cases with at least 6 bCAM measurements over postoperative day (POD) 1 to 4 had consistent results, as sugammadex compared with neostigmine was associated with an estimated odds ratio for postoperative delirium of 1.20 (0.82-1.77), P = .346. Sugammadex was significantly associated with an increased incidence of early postoperative delirium, with an estimated odds ratio of 1.71 (1.07-2.72), P = .025. Further analysis showed no treatment-by-age interaction for either postoperative delirium (P = .637) or postoperative early delirium (P = .904).

CONCLUSIONS

Compared to neostigmine, use of sugammadex for reversal of neuromuscular block was not associated with an increased risk of postoperative delirium in this retrospective single-center study. Though sugammadex was associated with a statistically significant increased risk of postoperative early delirium, the difference was small and not clinically relevant, and may reflect the presence of unknown confounders.

The role of dexmedetomidine administered via intravenous infusion as adjunctive therapy to mitigate postoperative delirium and postoperative cognitive dysfunction in elderly patients undergoing regional anesthesia: a meta-analysis of randomized controlled trials

STUDY OBJECTIVE

This meta-analysis aimed to assess whether continuous intravenous administration of DEX during surgery can be part of the measures to prevent the onset of postoperative delirium and postoperative cognitive dysfunction in elderly individuals following regional anesthesia.

METHODS

We searched the databases of PubMed, Embase, the Cochrane Library and China National Knowledge Infrastructure (by June 1, 2023) for all available randomized controlled trials assessing whether intravenous application of dexmedetomidine can help with postoperative delirium and postoperative cognitive dysfunction in the elderly with regional anesthesia. Subsequently, we carried out statistical analysis and graphing using Review Manager software (RevMan version 5.4.1) and STATA software (Version 12.0).

MAIN RESULTS

Within the scope of this meta-analysis, a total of 18 randomized controlled trials were included. Among them, 10 trials aimed to assess the incidence of postoperative delirium as the primary outcome, while the primary focus of the other 8 trials was on the incidence of postoperative cognitive dysfunction. The collective evidence from these 10 studies consistently supports a positive relationship between the intravenous administration of dexmedetomidine and a decreased risk of postoperative delirium (RR: 0.48; 95%CI: 0.37 to 0.63, p < 0.00001, I2 = 0%). The 8 literature articles and experiments evaluating postoperative cognitive dysfunction showed that continuous intravenous infusion of dexmedetomidine during the entire surgical procedure exhibited a positive preventive effect on cognitive dysfunction among the elderly population with no obvious heterogeneity (RR: 0.35; 95%CI: 0.25 to 0.49,p < 0.00001, I2 = 0%).

CONCLUSION

Administering dexmedetomidine intravenously during surgery can potentially play a significant role in preventing postoperative delirium and postoperative cognitive dysfunction in patients older than 60 years with regional anesthesia according to this meta-analysis.

Ketofol versus Dexmedetomidine for preventing postoperative delirium in elderly patients undergoing intestinal obstruction surgeries: a randomized controlled study

PURPOSE

Postoperative delirium (POD) is considered the most common postoperative neurological complication in elderly patients. The aim of this study was to evaluate the efficacy of the administration of ketofol versus dexmedetomidine (DEX) for minimizing POD in elderly patients undergoing urgent exploration for intestinal obstruction.

METHODS

This prospective double-blinded randomized clinical trial was conducted on 120 elderly patients undergoing urgent exploration for intestinal obstruction. Patients were randomly allocated to one of the three groups: Group C (control group) patients received normal saline 0.9%, group D received dexmedetomidine, and group K received ketofol (ketamine: propofol was 1:4). The primary outcome was the incidence of POD. Secondary outcomes were incidence of emergence agitation, postoperative pain, consumption of rescue opioids, hemodynamics, and any side effects.

RESULTS

The incidence of POD was statistically significantly lower in ketofol and DEX groups than in the control group at all postoperative time recordings. Additionally, VAS scores were statistically significantly decreased in the ketofol and DEX groups compared to the control group at all time recordings except at 48 and 72 h postoperatively, where the values of the three studied groups were comparable. The occurrence of emergence agitation and high-dose opioid consumption postoperatively were found to be significant predictors for the occurrence of POD at 2 h and on the evening of the 1st postoperative day.

CONCLUSION

The administration of ketofol provides a promising alternative option that is as effective as DEX in reducing the incidence of POD in elderly patients undergoing urgent exploration for intestinal obstruction.

TRIAL REGISTRATION

This clinical trial was approved by the Institutional Review Board (IRB) at Zagazig University (ZU-IRB# 6704// 3/03/2021) and ClinicalTrials.gov (NCT04816162, registration date 22/03/ 2021). The first research participant was enrolled on 25/03/2021).

Different Sedation Strategies in Older Patients Receiving Spinal Anesthesia for Hip Surgery on Postoperative Delirium: A Randomized Clinical Trial

Background

Postoperative delirium (POD) is of great concern as a complication of surgery in older adult patients. Sedation strategies influence the development of POD. This study compared how sedation strategies administered during spinal anesthesia influenced POD in patients aged ≥65 years undergoing elective surgery for hip fracture repair.

Patients and Methods

A randomized clinical trial was conducted from 1 August 2021 to 30 June 2022 at a single academic medical center. Two hundred and twenty-six patients were randomly divided into four groups: lighter sedation with propofol (LP), heavier sedation with propofol (HP), lighter sedation with dexmedetomidine (LD), and heavier sedation with dexmedetomidine (HD). The incidence of delirium was the primary outcome and was assessed daily by the blinded Confusion Assessment Method.

Results

There was a significant association between dexmedetomidine (LD+HD group) and a lower incidence of delirium (11.9% [13/109] vs the propofol group (23.6% [26/110]; Risk ratio, 0.51; 95% CI, 0.274 to 0.929; p=0.024). In the propofol group, heavier sedation had a higher rate of POD (32.7% [18/55] vs the lighter sedation group (14.5% [8/55]; Risk ratio, 2.25; 95% CI, 1.069 to 4.736; p=0.025).

Conclusion

Dexmedetomidine was associated with a lower incidence of delirium than that with propofol among older patients with hip fractures. In patients that received propofol, heavier sedation was associated with high incidence of POD.

Norepinephrine prevents hypotension in older patients under spinal anesthesia with intravenous propofol sedation: a randomized controlled trial

Reducing hypotension is crucial as hypotension is the most common side effect of spinal anesthesia, and in older patients with various comorbidities, it can lead to fatality. We hypothesized that continuous infusion of norepinephrine could effectively prevent hypotension in older patients undergoing hip surgery under spinal anesthesia with propofol sedation. The study randomly assigned patients aged ≥ 70 years to either a control (Group C, n = 35) or a norepinephrine group (Group N, n = 35). After spinal anesthesia, continuous infusion of propofol and normal saline or norepinephrine was initiated. The number of hypotensive episodes, the primary outcome, as well as other intraoperative hemodynamic events and postoperative complications were compared. In total, 67 patients were included in the final analysis. The number of hypotensive episodes was significantly higher in Group C than in Group N (p < 0.001). Furthermore, Group C required a greater amount of fluid to maintain normovolemia (p = 0.008) and showed less urine output (p = 0.019). However, there was no difference in postoperative complications between the two groups. Continuous intravenous infusion of prophylactic norepinephrine prevented hypotensive episodes, reduced the requirement of fluid, and increased the urine output in older patients undergoing unilateral hip surgery under spinal anesthesia with propofol sedation.Clinical trial registration number: KCT0005046 ( https://cris.nih.go.kr ). IRB number: 2020-0533 (Institutional Review Board of Asan Medical Center, approval date: 13/APR/2020).

Spinal anesthesia in elective lumbar spinal surgery

Spinal anesthesia (SA) is gaining recognition as a safe and efficacious regional alternative to general anesthesia for elective lumbar surgery. However, unfamiliarity with management issues related to its use has limited the adoption of awake spine surgery, despite its benefits. Few centers in the United States routinely offer SA for elective lumbar surgery, and a comprehensive workflow to standardize SA for lumbar surgery is lacking. In this article, we examine recent literature on the use of SA in lumbar surgery, review the experience of our institution with SA in lumbar surgery, and provide a cohesive outline to streamline the implementation of SA from the perspective of the anesthesiologist. We review the critical features of SA in contemporary lumbar surgery, including selection of patients, methods of SA, intraoperative sedation, and management of several important technical considerations. We aimed to flatten the learning curve to improve the availability and accessibility of the technique for eligible patients.

Towards a potent and rapidly reversible Dexmedetomidine-based general anesthetic

IN CONCLUSION

Our results suggest that Dex supplemented with a low dose of a second agent creates a potent anesthetic that is rapidly reversed by atipamezole and caffeine.

Effects of Remimazolam and Propofol on Emergence Agitation in Elderly Patients Undergoing Hip Replacement: A Clinical, Randomized, Controlled Study

Purpose

The aim of this study was to compare the effects of remimazolam and propofol on emergence agitation (EA) in elderly patients undergoing hip replacement.

Methods

A total of 60 elderly patients undergoing hip replacement were recruited for this prospective, single-center, clinical, randomized, controlled study from February to April 2023. They were randomly assigned to two groups: the remimazolam group (group R) and the propofol group (group P). In group R, remimazolam was administered intravenously during the induction and maintenance of anesthesia, In group P, propofol was used during the induction and maintenance of anesthesia. The incidence of EA was recorded as the primary indicator. Secondary indicators included heart rate (HR) and mean arterial pressure (MAP) values at the following moments: 5 min prior to anesthetic induction (T0), 1 min following induction (T1), 5 min after the laryngeal mask was inserted (T2), the beginning of surgery (T3), the moment the laryngeal mask was removed (T4), and the overall incidence of postoperative adverse events (bleeding or splitting of the surgical incision, removal of the intravenous infusion needle, falling off the bed, hypoxemia, and hypertension).

Results

The incidence of EA was significantly lower in group R than in group P (10% vs 33%, P < 0.05). At T1, T2, and T3, the HR and MAP values of group R were higher than those of group P (P < 0.05). The overall incidence of postoperative adverse events was significantly lower in group R than in group P (P < 0.05).

Conclusion

Remimazolam further reduced the incidence of emergence agitation when compared to propofol during geriatric hip replacement. Moreover, it has a minor hemodynamic effect and lower the incidence of postoperative adverse events.

Dexmedetomidine-induced anesthesia in elderly patients undergoing hip replacement surgery

BACKGROUND

A femoral neck fracture is a common and frequently reported issue in orthopedics, with a greater rate of incidence among the elderly. Due to their advanced age and the presence of some primary diseases, both anesthesia and surgery are increasingly difficult in elderly patients with a femoral neck fractures. In fact, general anesthesia can easily induce complications such as cognitive dysfunction, which is not conducive to postoperative recovery.

AIM

To analyze the efficacy of dexmedetomidine in inducing anesthesia for elderly patients undergoing hip replacement surgery.

METHODS

A total of 98 elderly patients undergoing hip replacement in our hospital from June 2020 to June 2021 were randomly divided into control group (49 cases) and observation group (49 cases). The control group was given general anesthesia, and the observation group was combined with dexmedetomidine for anesthesia on the basis of the control group. Both groups were observed until the patients were discharged. The vital signs, serum inflammatory factors and renal function indexes of the two groups were compared before, during and 6 h after operation. The postoperative recovery and adverse events of the two groups were statistically analyzed.

RESULTS

Compared with the mean arterial pressure of the two groups, the intraoperative and postoperative 6 h was higher than that before the operation, the intraoperative was lower than the postoperative 6 h (P < 0.05); the blood oxygen saturation of the two groups was higher than that before operation and 6 h after operation, and the observation group was higher than the control group 6 h after operation (P < 0.05). The heart rate of the two groups was lower during and 6 h after operation than that before operation, and higher at 6 h after operation than that during operation (P < 0.05). The levels of serum C-reactive protein, tumor necrosis factor-α, interleukin-1β and kidney injury molecule-1 in the two groups were higher during operation and 6 h after operation than those before operation (P < 0.05). The level of serum urea nitrogen in the two groups was higher than that before operation, and that in the observation group was lower than that in the control group (P < 0.05). During hospitalization, the first time of getting out of bed, recovery time of grade II muscle strength, recovery time of grade III muscle strength and hospitalization time in the observation group were shorter than those in the control group (P < 0.05).

CONCLUSION

Dexmedetomidine can effectively improve the vital signs of elderly patients undergoing hip replacement surgery, reduce the body's inflammatory response and renal function damage, and promote postoperative recovery. Meanwhile, dexmedetomidine showcased a good safety profile and a good anesthetic outcome.

Depth of anesthesia, temperature, and postoperative delirium in children and adolescents undergoing cardiac surgery

BACKGROUND

After pediatric cardiosurgical interventions, postoperative delirium can occur, which can be associated with undesirable consequences during and after the hospital stay. It is therefore important to avoid any factors causing delirium as far as possible. Electroencephalogram (EEG) monitoring can be used during anesthesia to individually adjust dosages of hypnotically acting drugs. It is necessary to gain knowledge about the relationship between intraoperative EEG and postoperative delirium in children.

METHODS

In a dataset comprising 89 children (53 male, 36 female; median age: 0.99 (interquartile range: 0.51, 4.89) years) undergoing cardiac surgery involving use of a heart-lung machine, relationships between depth of anesthesia as measured by EEG (EEG index: Narcotrend Index (NI)), sevoflurane dosage, and body temperature were analyzed. A Cornell Assessment of Pediatric Delirium (CAP-D) score ≥ 9 indicated delirium.

RESULTS

The EEG could be used in patients of all age groups for patient monitoring during anesthesia. In the context of induced hypothermia, EEG monitoring supported individually adjusted sevoflurane dosing. The NI was significantly correlated with the body temperature; decreasing temperature was accompanied by a decreasing NI. A CAP-D score ≥ 9 was documented in 61 patients (68.5%); 28 patients (31.5%) had a CAP-D < 9. Delirious patients with an intubation time ≤ 24 h showed a moderate negative correlation between minimum NI (NImin) and CAP-D (rho = -0.41, 95% CI: -0.70 - -0.01, p = 0.046), i.e., CAP-D decreased with increasing NImin. In the analysis of all patients' data, NImin and CAP-D showed a weak negative correlation (rho = -0.21, 95% CI: -0.40 - 0.01, p = 0.064). On average, the youngest patients had the highest CAP-D scores (p = 0.002). Patients with burst suppression / suppression EEG had a longer median intubation time in the intensive care unit than patients without such EEG (p = 0.023). There was no relationship between minimum temperature and CAP-D score.

CONCLUSIONS

The EEG can be used to individually adjust sevoflurane dosing during hypothermia. Of the patients extubated within 24 h and classified as delirious, patients with deeper levels of anesthesia had more severe delirium symptoms than patients with lighter levels of anesthesia.