Dexmedetomidine: present and future directions

Dexmedetomidine promotes necroptosis by upregulating PARP1 in non-small cell lung cancer

The score and prognostic value of necroptosis were analyzed in the TCGA and GSE120622 datasets. Necroptosis has the highest correlation with the immune microenvironment, and the high score in NSCLC correlates with poor prognosis. Differentially expressed genes between non-small cell lung cancer (NSCLC) and controls in both datasets were identified and subjected to construct co-expression networks, respectively. Black and blue modules were selected because of high correction with necroptosis. The intersected two module genes were mainly involved in immune and inflammatory response, cell cycle process and DNA replication. Nine marker genes of necroptosis were identified in these modules and considered as candidate genes. Based on candidate genes, we identified two clusters utilizing concordance clustering, additionally dividing NSCLC samples into high- and low-risk groups. There were significant differences in overall survival between two clusters and between high- and low-risk groups. Furthermore, PARP1 was found among the candidate genes to be the target gene of dexmedetomidine acting on necroptosis. Molecular experimental results found that PARP1 was highly expressed in the dexmedetomidine treated NSCLC compared with the NSCLC. Candidate genes associated with necroptosis may provide a powerful prognostic tool for precision oncology. Dexmedetomidine may target PARP1 to promote necroptosis and then affect NSCLC.

Research trends related to emergence agitation in the post-anaesthesia care unit from 2001 to 2023: A bibliometric analysis

Background

Emergence agitation (EA) is a behavioural disturbance encountered during the recovery phase of patients following general anaesthesia. It is characterised by restlessness, involuntary limb movements, and drainage tube withdrawal and may significantly harm patients and medical staff. The mechanism of EA has not been fully understood and is still a challenging subject for researchers.

Methods

We extracted relevant publications published between 1 January 2001 and 31 December 2023 on the Web of Science Core Collection platform. VOSviewer software was utilised to analyse the retrieved literature and predict the development trends and hotspots in the field.

Results

The results show that the number of publications grew annually, with China contributing the most, followed by the United States and South Korea. The co-occurrence of keywords "children," "propofol," "risk factors" are current research hotspots. Owing to its self-limiting and short-duration characteristics, EA lacks standardised clinical time guidelines and objective assessment tools, which may be the focus of future research in this field.

Conclusions

Understanding the research hotspots and the latest progress in this field, this study will help to continuously improve the clinical understanding and management of EA, and help to timely identify environmental risk factors for EA in clinical practice.

Comparison of intranasal dexmedetomidine versus oral midazolam for premedication in pediatric patients: an updated meta-analysis with trial-sequential analysis

BACKGROUND

Midazolam is routinely used as preanesthetic medication in pediatric patients. Recently, dexmedetomidine has emerged as an alternative as a premedicant. We aimed to add more evidence about the efficacy and safety of two common routes of administration for pediatric premedication: oral midazolam versus intranasal dexmedetomidine.

METHODS

We systematically searched Randomized Controlled Trials (RCTs) involving patients ≤ 18 years old undergoing preanesthetic medication and comparing intranasal dexmedetomidine with oral midazolam. Risk Ratio (RR) and Mean Difference (MD) with 95% Confidence Intervals (95% CI) were computed using a random effects model. Trial-sequential analyses were performed to assess inconsistency.

RESULTS

Sixteen RCTs (1,239 patients) were included. Mean age was 5.5 years old, and most procedures were elective. There was no difference in satisfactory induction or mask acceptance (RR = 1.15, 95% CI 0.97-1.37; p = 0.11). There was a higher incidence of satisfactory separation from parents in the dexmedetomidine group (RR = 1.40; 95% CI 1.13-1.74; p = 0.002). Dexmedetomidine was also associated with a reduction in the incidence of emergence agitation (RR = 0.35; 95% CI 0.14-0.88; p = 0.02). Heart rate and mean arterial pressure were marginally lower in the dexmedetomidine group but without clinical repercussions.

CONCLUSION

Compared with oral midazolam, intranasal dexmedetomidine demonstrated better separation from parents and lower incidence of emergence agitation in pediatric premedication, without a difference in satisfactory induction. Intranasal dexmedetomidine may be a safe and effective alternative to oral midazolam for premedication in pediatric patients.

Dexmedetomidine inhibits the migration, invasion, and glycolysis of glioblastoma cells by lactylation of c-myc

BACKGROUND

Glioblastoma (GBM) is a brain tumor with poor prognosis. Dexmedetomidine (Dex) regulates the biological behaviors of tumor cells to accelerate or decelerate cancer progression.

OBJECTIVE

We investigated the effects of Dex on the migration, invasion, and glycolysis in GBM.

METHODS

The concentration of Dex was determined using the cell counting kit-8 assay. The impacts of Dex on biological behaviors of GBM cells were assessed using Transwell assay, XF96 extracellular flux analysis, and western blot. The expression of c-Myc was examined using reverse transcription-quantitative polymerase chain reaction. The lactylation or stability of c-Myc was measured by western blot after immunoprecipitation or cycloheximide treatment.

RESULTS

We found that Dex (200 nM) inhibited GBM cell viability, migration, invasion, and glycolysis. C-Myc was highly expressed in GBM cells and was decreased by Dex treatment. Moreover, Dex suppressed lactylated c-Myc levels via suppressing glycolysis, thereby reducing the protein stability of c-Myc. Sodium lactate treatment abrogated the effects of Dex on the biological behaviors of GBM cells.

CONCLUSION

Dex suppressed the migration, invasion, and glycolysis of GBM cells via inhibiting lactylation of c-Myc and suppressing the c-Myc stability, suggesting that Dex may be a novel therapeutic drug for GBM treatment.

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.

Evaluation of the testicular artery Doppler velocimetry and its correlation with sperm defects in domestic cats

Several studies have demonstrated the correlation between Doppler velocimetric parameters of testicular artery and semen quality in domestic species, but in felines data are scarce. This study aimed to correlate the Doppler velocimetry of the testicular artery with sperm kinetics and sperm defects, in sedated and non-sedated cats. Forty tomcats were divided into two groups: sedated (SG; n=20) with dexmedetomidine (10 µm/kg) and ketamine (12 mg/kg), and non-sedated (NSG; n=20). The animals were subjected to ultrasound Doppler velocimetry of the distal supratesticular and marginal region of the testicular artery and subsequently orchiectomized. Epididymal tail spermatozoa were recovered and analyzed using a CASA system for motility, and morphology took place. Animals of SG presented a significantly higher velocity in the marginal region of the cat's testicular artery [peak systolic velocity (PSV) 11.51 cm/s; end-diastolic velocity (EDV) 7.72 cm/s] compared to NSG (PSV 7.72 cm/s, P < 0.001; EDV 4.93 cm/s, P < 0.001). Sedated cats presented higher pulsatility and resistivity indexes than non-sedated cats. The supratesticular PSV of NSG was moderately correlated with major (rs = 0621; P < 0.001) and total sperm defects (rs = 0614; P < 0001). Doppler velocimetry was fairly correlated with minor, major, and total sperm defects. In conclusion, Doppler velocimetric evaluation emerges as an important possibility in the reproductive evaluation of tomcats, once the testicular artery hemodynamics were associated with sperm defects. However, it is advisable to carry out this evaluation in non-sedated animals. If sedation is necessary, peripheral vasoconstriction should be considered.

Sinus Arrest Related to Dexmedetomidine Infusion in an Infant; a Case Report and Review of Current Literature

Background: Dexmedetomidine, an alpha 2 agonist, has emerged as a desirable sedative agent in the pediatric intensive care unit due to its minimal effect on respiratory status and reduction in delirium. Bradycardia and hypotension are common side effects, however there are emerging reports of more serious cardiovascular events, including sinus arrest and asystole. These case reports have been attributed to high vagal tone or underlying cardiac conduction dysfunction. Objectives: To describe the development of sinus arrest during sedation with dexmedetomidine in a patient without clinical features of high vagal tone, underlying cardiac conduction dysfunction, or intervening episodes of bradycardia. Case Presentation: An 11 month-old patient requiring sedation during mechanical ventilation for acute respiratory failure secondary to Adenovirus. To facilitate sedation, a dexmedetomidine infusion was initiated at .5 mcg/kg/hr and increased to maximum 1 mcg/kg/hr. Within 8 hours of initiating therapy, the patient had three episodes of sinus arrest. There was no intervening bradycardia between episodes and no further episodes occurred following discontinuation of dexmedetomidine. The patient did not have any clinical features associated with high vagal tone or underlying cardiac conduction dysfunction. Conclusions: As result of these findings, understanding risk factors for bradycardia, or more serious hemodynamic instability with dexmedetomidine infusions, is important to help identify high risk patients and weigh the associated risks and benefits of its administration.

Identifying the pathophysiological traits of obstructive sleep apnea during dexmedetomidine sedation

Dexmedetomidine (DEX) has been described as a safe sedative in clinical practice, but its effects on the pathophysiological traits of obstructive sleep apnea (OSA) are unclear. We estimated the effects of DEX sedation on the four key pathophysiological traits of OSA (pharyngeal collapsibility, dilator muscle function, arousal threshold, and loop gain) in adult patients with OSA by conducting a secondary analysis of a prospective diagnostic trial. Pathophysiological traits estimated from polysomnography and the respiratory parameters under natural sleep and DEX-induced sleep were compared. Bivariate and multivariate linear regression analyses were used to estimate the relationship between pathophysiological traits and OSA severity for both sleep states. Adult patients with OSA had a significantly higher pharyngeal collapsibility (Vpassive: 44.9 [15.7 to 53.8] vs. 53.3 [34.2 to 66.3] %eupnea, p < 0.001), arousal threshold (178.5 [132.5 to 234.6] vs. 140.5 [123.2 to 192.3] %eupnea, p < 0.001), and loop gain (LG1: 0.74 ± 0.25 vs. 0.60 ± 0.17, p < 0.001; LGn: 0.52 ± 0.12 vs. 0.44 ± 0.08, p < 0.001) during DEX-induced sleep compared with natural sleep. There was no significant difference in dilator muscle function or PSG respiratory parameters between natural versus DEX-induced sleep states. Bivariate regression analysis showed varying degrees of correlation between OSA traits and severity. Multiple regression analysis indicated that collapsibility was the strongest predictor of the apnea-hypopnea index for both sleep states. Dexmedetomidine sedation in patients with OSA increased the pharyngeal collapsibility without impairing dilator muscle function, while elevating arousal threshold and increasing loop gain.

Central α2-adrenergic mechanisms regulate human sympathetic neuronal discharge strategies

The present study investigated the impact of central α2-adrenergic mechanisms on sympathetic action potential (AP) discharge, recruitment and latency strategies. We used the microneurographic technique to record muscle sympathetic nerve activity and a continuous wavelet transform to investigate postganglionic sympathetic AP firing during a baseline condition and an infusion of a α2-adrenergic receptor agonist, dexmedetomidine (10 min loading infusion of 0.225 µg kg-1; maintenance infusion of 0.1-0.5 µg kg h-1) in eight healthy individuals (28 ± 7 years, five females). Dexmedetomidine reduced mean pressure (92 ± 7 to 80 ± 8 mmHg, P < 0.001) but did not alter heart rate (61 ± 13 to 60 ± 14 bpm; P = 0.748). Dexmedetomidine reduced sympathetic AP discharge (126 ± 73 to 27 ± 24 AP 100 beats-1, P = 0.003) most strongly for medium-sized APs (normalized cluster 2: 21 ± 10 to 5 ± 5 AP 100 beats-1; P < 0.001). Dexmedetomidine progressively de-recruited sympathetic APs beginning with the largest AP clusters (12 ± 3 to 7 ± 2 clusters, P = 0.002). Despite de-recruiting large AP clusters with shorter latencies, dexmedetomidine reduced AP latency across remaining clusters (1.18 ± 0.12 to 1.13 ± 0.13 s, P = 0.002). A subset of six participants performed a Valsalva manoeuvre (20 s, 40 mmHg) during baseline and the dexmedetomidine infusion. Compared to baseline, AP discharge (Δ 361 ± 292 to Δ 113 ± 155 AP 100 beats-1, P = 0.011) and AP cluster recruitment elicited by the Valsalva manoeuvre were lower during dexmedetomidine (Δ 2 ± 1 to Δ 0 ± 2 AP clusters, P = 0.041). The reduction in sympathetic AP latency elicited by the Valsalva manoeuvre was not affected by dexmedetomidine (Δ -0.09 ± 0.07 to Δ -0.07 ± 0.14 s, P = 0.606). Dexmedetomidine reduced baroreflex gain, most strongly for medium-sized APs (normalized cluster 2: -6.0 ± 5 to -1.6 ± 2 % mmHg-1; P = 0.008). These data suggest that α2-adrenergic mechanisms within the central nervous system modulate sympathetic postganglionic neuronal discharge, recruitment and latency strategies in humans. KEY POINTS: Sympathetic postganglionic neuronal subpopulations innervating the human circulation exhibit complex patterns of discharge, recruitment and latency. However, the central neural mechanisms governing sympathetic postganglionic discharge remain unclear. This microneurographic study investigated the impact of a dexmedetomidine infusion (α2-adrenergic receptor agonist) on muscle sympathetic postganglionic action potential (AP) discharge, recruitment and latency patterns. Dexmedetomidine infusion inhibited the recruitment of large and fast conducting sympathetic APs and attenuated the discharge of medium sized sympathetic APs that fired during resting conditions and the Valsalva manoeuvre. Dexmedetomidine infusion elicited shorter sympathetic AP latencies during resting conditions but did not affect the reductions in latency that occurred during the Valsalva manoeuvre. These data suggest that α2-adrenergic mechanisms within the central nervous system modulate sympathetic postganglionic neuronal discharge, recruitment and latency strategies in humans.

Effects of dexmedetomidine on depression-like behaviour in chronic restraint stress mice: Involvement of specific brain regions

It is crucial to develop novel antidepressants. Dexmedetomidine (DEX) can exert antidepressant effects, but its underlying mechanism remains unclear. We used chronic restraint stress (CRS) to induce depression-like behaviour in mice and administered low-dose DEX (2 μg/kg per day) during CRS modelling or one injection of high-dose DEX (20 μg/kg) after CRS. The results of the behavioural tests revealed that both methods ameliorated CRS-induced depression. The brain slices of the mice were subjected to immunohistochemical staining for c-fos and phosphorylated ERK (pERK). Results showed that the continuous low-dose DEX-treated group, but not the single high-dose DEX-treated group expressed less c-fos in the nucleus locus coeruleus (LC) with a mean optical density (MOD) of 0.06. Other brain regions, including the dentate gyrus (DG), pyriform cortex (Pir), anterior part of paraventricular thalamic nucleus (PVA), arcuate nucleus (Arc), and core or shell of accumbens nucleus (Acbc or Acbs), presented differences in c-fos expression. In contrast, the low-dose DEX-treated group exhibited three-fold greater pERK expression in the LC of the CRS mice, with a MOD of 0.15. Pir, cingulate cortex (Cg) and, anterior and posterior part of paraventricular thalamic nucleus (PVA and PVP) exhibited pERK expression differences due to distinct reagent treatments. These changes indicate that the responses of brain regions to different DEX administration methods and doses vary. This study confirmed the ability of DEX to ameliorate CRS-induced depression and identified candidate target brain regions, thus providing new information for the antidepressant mechanism of DEX.

Dexmedetomidine on the interplay of IL-6 and STAT3 pathways in adrenal gland damage-induced scalding burns in rats

Scalding burns are a common form of thermal injury that often leads to systemic complications. Pro-inflammatory cytokines like interleukin-6 (IL-6) and the activation of signal transducer and activator of transcription 3 (STAT3) pathways have been linked to the pathophysiology of organ damage caused by burns. This study aimed to investigate the potential therapeutic effects of dexmedetomidine, an α2-adrenergic receptor agonist with anti-inflammatory properties, on the interplay of IL-6 and STAT3 pathways in adrenal gland damage following scalding burns in rats. Twenty-eight rats were divided randomly into four groups. Rats in group 1 (n=7, control) were given only 0.9% intraperitoneal (i.p.) NaCl. Rats in group 2 (n=7, DEX) were exposed to 25°C water for 17 s on day 1 and received 100 mcg/kg/day dexmedetomidine i.p. for 3 days; for rats in group 3 (n=7, Burn), boiling water of 94°C was applied inside for 17 s. Rats in group 4 (n=7, Burn+DEX) were exposed to 94°C water for 17 s and received 100 mcg/kg/day dexmedetomidine i.p. for 3 days. Adrenal gland tissues were histopathological examined, and STAT3, IL-6, and TUNEL staining were performed using immunohistochemically. Our results revealed that scalding burns increased IL-6 and STAT3 expression in the adrenal glands of rats. Histological analysis demonstrated that dexmedetomidine administration ameliorated adrenal gland damage and reduced inflammatory cell infiltration. Our findings suggest that dexmedetomidine protects the adrenal glands in scalding burns. This protection appears to be mediated, at least in part, by its modulation of IL-6 and STAT3 pathways.

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.

Designing Chromane Derivatives as α2A-Adrenoceptor Selective Agonists via Conformation Constraint

Enhancing the selectivity of alpha2-adrenoceptor (α2A-AR) agonists remains an unresolved issue. Herein, we reported the design of an α2A-AR agonist using the conformation constraint method, beginning with medetomidine. The structure-activity relationship indicated that the 8-substituent of chromane derivatives exerted the most pronounced effect on α2A-AR agonistic activity. Compounds A9 and B9 were identified as the most promising, exhibiting EC50 values of 0.78 and 0.23 nM, respectively. Their selectivity indexes surpassed dexmedetomidine (DMED) by 10-80 fold. In vivo studies demonstrated that both A9 and B9 dose-dependently increased the loss of righting reflex in mice, with ED50 values of 1.54 and 0.138 mg/kg, respectively. Binding mode calculations and mutation studies suggested the indispensability of the hydrogen bond between ASP1283.32 and α2A-AR agonist. In particular, A9 and B9 showed no dual reverse pharmacological effect, a characteristic exhibited by DMED in α2A-AR activation.

Comparisons of different general anesthetic techniques on immune function in patients undergoing flap reconstruction for oral cancer

BACKGROUND

Anesthetic-induced immunosuppression is of particular interest in tumor surgery. This study aimed to investigate the influence of the 4 most common general anesthetic techniques on immune function in patients undergoing flap reconstruction for oral cancer.

METHODS

116 patients were randomly divided into 4 groups. Patients in group S were given sevoflurane-based anesthesia. Group P was administered propofol-based anesthesia. The SD group received sevoflurane combined with dexmedetomidine anesthesia. The propofol combined with dexmedetomidine anesthesia (PD) group received PD. Blood samples were obtained at 5 time points: baseline (T0), 1 hour after the start of the operation (T1), end of the operation (T2), 24 hours (T3), and 48 hours (T4) after the operation. Lymphocyte subsets (including CD3+, CD4+, CD8+, and B lymphocytes) and dendritic cells were analyzed by flow cytometry. Blood glucose, norepinephrine, and cortisol levels were measured using ELISA and a blood gas analyzer respectively.

RESULTS

In total, 107 patients were included in the final analysis. Immunological indicators, except CD8+ counts, were all decreased in groups S, P, and SD at T1-4 compared with the baseline value, and the counts of CD3+, CD4+, and dendritic cells, as well as CD4+/CD8+ ratios, were significantly higher in the PD group than in the S, P, and SD at T1-3 (P < .05). There were no significant differences between groups P and SD at any observation time point. Intraoperative stress indices, including norepinephrine and cortisol levels, were significantly lower in the PD group than in the other 3 groups at T1-2 (P < .05).

CONCLUSION

These findings suggest that PD as a probably optimal choice can alleviate immunosuppression in patients undergoing flap reconstruction for oral cancer.

Effects of perioperative dexmedetomidine on delayed graft function following renal transplant: a systematic review and meta-analysis

BACKGROUND

Dexmedetomidine, a highly selective alpha-2 adrenoceptor agonist with sedative and analgesic effects, has been suggested in recent studies to possess renoprotective properties. Dexmedetomidine may reduce the incidence of delayed graft function and contribute to effective pain control post-renal transplantation. The primary objective of this systematic review was to assess whether dexmedetomidine decreases the occurrence of delayed graft function in renal transplant patients.

METHODS

Databases including MEDLINE, EMBASE, and CENTRAL were comprehensively searched from their inception until March 2023. The inclusion criteria covered all Randomized Clinical Trials (RCTs) and observational studies comparing dexmedetomidine to control in adult patients undergoing renal transplant surgery. Exclusions comprised case series and case reports.

RESULTS

Ten RCTs involving a total of 1358 patients met the eligibility criteria for data synthesis. Compared to the control group, the dexmedetomidine group demonstrated a significantly lower incidence of delayed graft function (OR = 0.71, 95% CI 0.52-0.97, p = 0.03, GRADE: Very low, I2 = 0%). Dexmedetomidine also significantly prolonged time to initiation of rescue analgesia (MD = 6.73, 95% CI 2.32-11.14, p = 0.003, GRADE: Very low, I2 = 93%) and reduced overall morphine consumption after renal transplant (MD = -5.43, 95% CI -7.95 to -2.91, p < 0.0001, GRADE: Very low, I2 = 0%). The dexmedetomidine group exhibited a significant decrease in heart rate (MD = -8.15, 95% CI -11.45 to -4.86, p < 0.00001, GRADE: Very low, I2 = 84%) and mean arterial pressure compared to the control group (MD = -6.66, 95% CI -11.27 to -2.04, p = 0.005, GRADE: Very low, I2 = 87%).

CONCLUSIONS

This meta-analysis suggests that dexmedetomidine may potentially reduce the incidence of delayed graft function and offers a superior analgesia profile as compared to control in adults undergoing renal transplants. However, the high degree of heterogeneity and inadequate sample size underscore the need for future adequately powered trials to confirm these findings.

Role of Dexmedetomidine and Clonidine With Hyperbaric Ropivacaine in Subarachnoid Block: A Comprehensive Review

Subarachnoid block (SAB), a fundamental technique in regional anesthesia, offers efficient anesthesia for various surgical procedures with advantages including rapid onset, reliable anesthesia, and reduced systemic effects compared to general anesthesia. Hyperbaric ropivacaine, a long-acting local anesthetic, has gained popularity due to its favorable pharmacokinetic profile and safety profile. However, to extend the duration and enhance the quality of anesthesia provided by hyperbaric ropivacaine, adjuvants such as dexmedetomidine and clonidine are frequently employed. This comprehensive review explores the roles of dexmedetomidine and clonidine as adjuvants to hyperbaric ropivacaine in SAB. It examines their pharmacological mechanisms, clinical efficacy, safety profiles, and comparative effectiveness in prolonging analgesia and enhancing anesthesia. The review synthesizes evidence from clinical studies to delineate the synergistic effects of these adjuvants, their impact on patient outcomes, and their potential advantages over traditional anesthesia techniques. Through a detailed analysis of current literature and clinical practices, this review aims to provide insights into optimizing the use of dexmedetomidine and clonidine in SAB protocols. It discusses clinical implications, offers recommendations for practice, and identifies future research directions to further enhance the efficacy and safety of SAB using these adjuvants.

Dexmedetomidine as a Short-Use Analgesia for the Immature Nervous System

Pain management in neonates continues to be a challenge. Diverse therapies are available that cause loss of pain sensitivity. However, because of side effects, the search for better options remains open. Dexmedetomidine is a promising drug; it has shown high efficacy with a good safety profile in sedation and analgesia in the immature nervous system. Though dexmedetomidine is already in use for pain control in neonates (including premature neonates) and infants as an adjunct to other anesthetics, the question remains whether it affects the neuronal activity patterning that is critical for development of the immature nervous system. In this study, using the neonatal rat as a model, the pharmacodynamic effects of dexmedetomidine on the nervous and cardiorespiratory systems were studied. Our results showed that dexmedetomidine has pronounced analgesic effects in the neonatal rat pups, and also weakly modified both the immature network patterns of cortical and hippocampal activity and the physiology of sleep cycles. Though the respiration and heart rates were slightly reduced after dexmedetomidine administration, it might be considered as the preferential independent short-term therapy for pain management in the immature and developing brain.

The EC50 of propofol with different doses of dexmedetomidine during gastrointestinal endoscopy: A double-blind, placebo-controlled trial

PURPOSE

The goal of this study was to evaluate the dose-response relationship between dexmedetomidine and propofol in sedating patients and to determine the optimal dosage of dexmedetomidine during gastrointestinal endoscopy.

METHODS

One hundred fifty patients were divided into 5 groups, each receiving a loading dose of dexmedetomidine (0.4, 0.6, 0.8, 1.0 µg/kg) or saline, with propofol for sedation. The median effective concentration (EC50) of propofol was calculated using the modified Dixon up-and-down approach. Adverse effects, vital signs, procedure, and recovery times were recorded.

RESULTS

The EC50 of propofol in groups NS, D0.4, D0.6, D0.8, and D1.0 were 3.02, 2.44, 1.97, 1.85, and 1.83 µg/mL, respectively. Heart rate in the dexmedetomidine groups decreased more than the NS group (P < .001). The mean arterial pressure (MAP) in the NS group experienced a decline compared to groups D0.8 and D1.0 when the plasma concentration and effect-site concentration reached equilibrium. Additionally, the respiratory rate was found to be lower in groups NS, D0.4, D0.6, and D0.8 (P < .05). Recovery time in groups D0.8 and D1.0 was longer than the NS group (P < .05). Bruggemann comfort scales score was higher in group D1.0 (P < .05). No significant difference was found in the incidences of hypotension and bradycardia, and the dose of ephedrine and atropine. Respiratory depression was significantly reduced in groups D0.8 and D1.0 compared to the NS group.

CONCLUSION

A single dose of 0.6 to 0.8 µg/kg of dexmedetomidine should be recommended in combination with propofol for gastrointestinal endoscopy. And the EC50 of propofol is 1.97 to 1.85 µg/mL.

Co-administration of naloxone and dexmedetomidine to simultaneously reverse acute effects of fentanyl and methamphetamine in rats

BACKGROUND

The incidence of combination methamphetamine (METH)-opioid overdose has substantially increased in recent years. While agitation is uncommon after the naloxone (NLX) reversal of opioids, it is a major clinical concern in acute METH intoxication and can be physiologically antagonized by opioid-induced sedation. This study aimed to perform initial preclinical analysis of the safety and efficacy of dexmedetomidine (DEXMED) co-administered with NLX to attenuate METH-induced locomotor activity, as a rat model of agitation, after the reversal of fentanyl (FENT)-induced sedation.

METHODS

Male Sprague Dawley rats were administered subcutaneous (SC) 0.1mg/kg FENT ± 1mg/kg METH. Fifteen min later, SC 0.1mg/kg NLX ± an increasing (0, 0.032, 0.056, and 0.1mg/kg) DEXMED dose was administered prior to the measurement of locomotor activity. After a washout period, the FENT ± METH and NLX ± DEXMED administration with the highest dose of DEXMED was administered for measurement of blood oxygen saturation and heart rate.

RESULTS

After the NLX reversal of FENT-induced sedation, adjunct DEXMED substantially and significantly reduced METH-induced locomotor activity (p<0.05) at all doses tested. While the addition of DEXMED did not significantly reduce blood oxygenation in METH treated rats, it did so in the absence of METH. Also, DEXMED significantly reduced heart rate compared to non-DEXMED treated groups and resulted in further significant reductions in the animals not exposed to METH (p<0.05).

CONCLUSIONS

These data provide preclinical evidence that DEXMED may be a safe and effective chemical restraint for METH-induced agitation after NLX opioid reversal.

Effect of intraoperative dexmedetomidine on recovery of gastrointestinal function after caesarean section undergoing spinal and epidural anesthesia: A randomized, double blind, placebo-controlled clinical trial

OBJECTIVE

Gastrointestinal dysfunction after cesarean section negatively affects postoperative recovery. Dexmedetomidine has been shown to improve postoperative gastrointestinal function in patients undergoing lumbar spinal fusion surgery and laparoscopic gastrectomy, but its role in cesarean section has not been fully elucidated. The study aimed to investigate the effect of dexmedetomidine on gastrointestinal function after cesarean section.

STUDY DESIGN

220 pregnant women who underwent elective cesarean section were randomized into group D and group S. Group D patients received a loading dose of 0.5 μg/kg of dexmedetomidine for 10 mins followed by a maintenance dose of 0.5 μg/kg/h intravenously immediately after the umbilical cord was cut intraoperatively, whereas the other group (group S) received an equivalent quantity of normal saline as loading and maintenance dose IV by infusion pump. The primary outcome was time to first flatus after surgery (hours). Secondary outcomes included time to first feces and first bowel sounds (hours), incidence rates of postoperative gastrointestinal complications, and the length of postoperative hospital stay (days).

RESULTS

Modified intention-to-treat analysis showed that patients in Group D had a significantly shorter time to first flatus (21 [16 to 28.25] vs. 25 [18 to 32.25] h; P = 0.014), time to first feces (45.5 [35.75 to 55.25] vs. 53 [40 to 60] h; P = 0.019), and time to first bowel sounds (P = 0.010), a lower incidence of abdominal distension (21[20.6 %] vs. 36[34.3 %], P = 0.027), shorter length of postoperative hospital stay (P = 0.010) compared to patients in Group S.

CONCLUSION

Intraoperative dexmedetomidine infusion reduces the time to first flatus, the incidence of abdominal distension, and shortens the length of hospital stay, promoting gastrointestinal function after cesarean section.

Opioid requirement and pain intensity after mandibular surgeries with dexmedetomidine administration in two ways: intraoperative infusion versus bolus injection

PURPOSE

The purpose of this study is to compare the opioid requirement and pain intensity after surgeries of mandibular fractures with administration of dexmedetomidine by two approaches of infusion and single bolus.

METHODS

In this double-blind clinical trial, the participants were randomized and matched in terms of age and gender in two groups (infusion and bolus). In both groups, the amount of narcotic used, hemodynamic indices, oxygen saturation, and pain intensity were collected based on the ten-point Visual Analogue Scale (VAS) at 7 time points for 24 h. SPSS version 24 software was used for data analysis. A significance level of less than 5% was considered.

RESULTS

A total of 40 patients were included in the study. There was no significant difference between the two groups in terms of gender, age, ASA class, and duration of surgery (P>0.05). There was no significant difference between the two groups in terms of nausea and vomiting and subsequently receiving anti-nausea medication (P>0.05). The need for opioid consumption after surgery was not different in two groups (P>0.05). Infusion of dexmedetomidine reduced postoperative pain more rapidly than its single bolus dose (P<0.05). However, over time, there was no significant difference between the two groups in terms of changes in oxygen saturation variables (P>0.05). Homodynamic indices including heart rate, systolic blood pressure, and diastolic blood pressure in the bolus group were significantly lower than the infusion group (P<0.05).

CONCLUSION

Administration of dexmedetomidine in the form of infusion can reduce postoperative pain better than bolus injection, with less probability of hypotension and bradycardia.

Dexmedetomidine as an Adjuvant to Nerve Block for Cancer Surgery: A Systematic Review and Meta-Analysis

Background/Objectives: Our understanding of dexmedetomidine, as an adjuvant to nerve blocks in cancer surgery, is characterized by a current lack of compelling evidence, and it remains unknown whether the potential benefits of use outweigh the risks. The aim of the study was to evaluate the benefit and safety profiles of dexmedetomidine as an adjuvant to nerve blocks in cancer surgery. Methods: Systematic searches were conducted in MEDLINE, ScienceDirect, Cochrane Library, Springer, medRxiv, and Scopus up to 17 May 2024. Risk ratios (RR) for binary outcomes and standardized mean differences (SMDs) for continuous outcomes were quantified. Results: Twenty studies were identified. In breast cancer surgery, the use of dexmedetomidine reduced 24 h total morphine consumption (SMD = -1.99 [95% CI -3.01 to -0.98], p = 0.0001, I2 = 91%, random effects) and prolonged the requirement for morphine rescue analgesia (SMD = 2.98 [95% CI 0.01 to 5.95], p = 0.05, I2 = 98%, random effects). In abdominal cancer surgery, the dexmedetomidine group had lower total sufentanil consumption (SMD = -1.34 [95% CI -2.29 to -0.40], p = 0.005, I2 = 84%, random effects). Dexmedetomidine reduced the VAS score and decreased postoperative nausea and vomiting (PONV). No studies using dexmedetomidine reported serious adverse events. Conclusions: Using dexmedetomidine as an adjuvant to nerve blocks in cancer surgery could lower the VAS pain score and prolong the regional anesthesia duration, which would lead to a decrease in total opioid consumption and possibly contribute to fewer PONV events. Furthermore, the reports of no serious adverse events indicate its good safety profile.

Protective effect of dexmedetomidine against delayed bone healing caused by morphine via PI3K/Akt mediated Nrf2 antioxidant defense system

Background

As a class of analgesics, opioids are frequently used to treat both acute and chronic moderate to severe pain. Patients frequently receive opioid painkillers after orthopedic accidents or surgeries. Evidence suggests that opioid drug users have a 55.1% higher risk of fracture and poor bone repair than non-users of opioid drugs. The key pathogenic alterations in the incidence and progression of poor bone repair are over apoptosis and aging of osteoblasts due to the stress caused by oxidation. Dexmedetomidine (Dex) has been proven to protect against a variety of degenerative illnesses by reducing oxidative stress. However, nothing is known about how it affects bone repair.

Methods

PI3K/Akt/Nrf2 pathway was detected by immunofluorescence and Western blot. SOD, CAT, JC-1, dihydroethidium and mitosox were used in the Oxidative Stress. Micro-CT, H&E and Masson's staining, immunohistochemically were performed to evaluate the therapeutic effects of DEX on calvarial defects in the morphine-induced rat model.

Results

We found that morphine-induced an imbalance in the metabolism and catabolism of primary rat Osteoblasts. However, these conditions could be inhibited by DEX treatment. In the meantime, DEX induced the expression of Nrf2-regulated antioxidant enzymes such as NQO1, HO-1, GCLm, GCLc, and TrxR1. DEX-mediated Nrf2 activation is linked to the PI3K/Akt signaling system. Furthermore, it has been established that intravenous DEX enhanced the growth of bone healing in a model of a surgically produced rat cranial lesion.

Conclusion

This is the first description of the unique DEX mechanism acting as a Nrf2 activator against morphine-mediated oxidative harm, raising the possibility that the substance may be used to prevent bone defects.

Donor Inhalation of Nebulized Dexmedetomidine Alleviates Ischemia-Reperfusion Injury in Rat Lung Transplantation

INTRODUCTION

The occurrence of lung ischemia-reperfusion injury (LIRI) after lung transplantation results in primary graft dysfunction (PGD) in more than 50% of cases, which seriously affects the prognosis of recipients. Currently, donor lung protection is the focus of research on improving graft survival in lung transplant recipients. Dexmedetomidine (Dex) is a widely used general anesthesia adjuvant in clinical practice to alleviate ischemia-reperfusion injury in the lungs, liver, heart, kidneys, and brain. However, intravenous infusion of Dex can cause negative effects on the cardiovascular system. Inhaling nebulized Dex can directly act on the alveolar tissue and alleviate its cardiovascular inhibitory effect by reducing drug intake. This study aimed to investigate the effect of donor nebulized Dex inhalation on LIRI after lung transplantation in rats.

METHODS

We randomly divided the male Sprague-Dawley rats into donor rats and recipient rats, and allowed the donor rats to inhale nebulized Dex or physiological saline 15 min before surgery. The donor lung was refrigerated for 8 h before each single-lung transplant. After 2 h of reperfusion of the transplanted lung, serum and transplanted lung tissue were collected. The wet-to-dry weight ratio of the lung tissue was measured, arterial blood gas was detected, and histopathology changes, oxidative stress, inflammatory reactions, and apoptosis were evaluated.

RESULTS

Pretransplant inhalation of Dex through the donor's lung reduced the injury of the transplanted lung, increased the levels of malondialdehyde and myeloperoxidase, and decreased the levels of superoxide dismutase and glutathione in the lung tissue. Moreover, nebulized Dex inhalation of the donor lung inhibited LIRI-induced tumor necrosis factor-α, interleukin-6, and inducible nitric oxide synthase expression and also suppressed nuclear factor kappa B phosphorylation. Nebulized Dex inhalation reduced the rate of cell apoptosis in the transplanted lung tissue by inhibiting the upregulation of Bax, downregulation of Bcl-2, and increase in caspase-3 lysis caused by LIRI.

CONCLUSION

Inhalation of atomized Dex is a potential donor lung protection strategy, which can be used to reduce LIRI after lung transplantation and may be helpful to improve the occurrence of PGD and prognosis of lung transplant recipients.

Application of intranasal dexmedetomidine in magnetic resonance imaging of preterm infants: The ED50, efficacy and safety analysis

BACKGROUND

Infants undergoing magnetic resonance imaging (MRI) often require pharmacological sedation. Dexmedetomidine serves as a novel sedative agent that induces a unique unconsciousness similar to natural sleep, and therefore has currently been used as the first choice for sedation in infants and young children.

OBJECTIVE

To determine the 50% effective dose (ED50) and 95% confidence interval (95%CI) of intranasal dexmedetomidine for MRI in preterm and term infants, and to observe the incidence of adverse events. To explore whether there were differences in ED50 and 95%CI, heart rate (HR) and blood oxygen saturation (SpO2), the induction time and wake-up time and the incidence of adverse events between the 2 groups, so as to provide guidance for clinical safe medication for the meanwhile.

METHODS

A total of 68 infants were prospectively recruited for MRI examination under drug sedation (1 week ≤ age ≤ 23 weeks or weight ≤ 5kg). The children were divided into 2 groups according to whether they had preterm birth experience (Preterm group, Atterm group). The Dixon up-and-down method was used to explore ED50. The basic vital signs of the 2 groups were recorded, and the heart rate and SpO2 were recorded every 5 minutes until the infants were discharged from the hospital. The induction time, wake-up time and adverse events were recorded.

RESULTS

The ED50 (95%CI) of intranasal dexmedetomidine in the Preterm group and the Atterm group were 2.23 (2.03-2.66) μg/kg and 2.64 (2.49-2.83) μg/kg, respectively (P < .05). the wake-up time was longer in Preterm group (98.00min) than in Atterm group (81.00 min) (P < .05), the incidence of bradycardia in Preterm group was 3/33, which was higher than that in Atterm group (1/35). There was no difference in the induction time between the 2 groups (P > .05), and there was no significant difference in other adverse events.

CONCLUSIONS

Intranasal dexmedetomidine can be safely used for sedation in preterm infants undergoing MRI. Compared with term infants, preterm infants have a lower dose of dexmedetomidine, a higher incidence of bradycardia, and a longer weak-up time.

Perioperative intravenous infusion of dexmedetomidine for alleviating postpartum depression after cesarean section: A meta-analysis and systematic review

The efficacy of perioperative dexmedetomidine (DEX) infusion as a precaution against postpartum depression (PPD) in women undergoing cesarean section has not been substantiated systematically. A literature search for RCTs on DEX against PPD was retrieved in the following databases from inception to January 3, 2024: PubMed, Embase, Web of Science, the Cochrane Library, CNKI, Wanfang, CBM, VIP, etc. A total of 13 RCTs with 1711 participants were included. Meta-analysis was performed by RevMan5.3 and Stata16 using a random-effects model. EPDS scores were significantly decreased in the DEX group within one week or over one week postpartum compared to the control group (SMD = -1.25, 95 %CI: -1.73 to -0.77; SMD = -1.08, 95 %CI: -1.43 to -0.73). The prevalence of PPD was significantly inferior to the control at both time points (RR = 0.36, 95 %CI: 0.24 to 0.54; RR = 0.39, 95 %CI: 0.26 to 0.57). Univariate meta-regression suggested that age influenced the heterogeneity of the EPDS scores (P = 0.039), and DEX infusion dose was a potential moderator (P = 0.074). The subgroup analysis results of PPD scores at both time points were consistent, showing that: ① Mothers younger than 30 years old had better sensitivity to DEX for treating PPD. ② The anti-PPD efficacy of continuous infusion of DEX by PCIA was superior to both single infusion and combined infusion. ③ DEX showed a better anti-PPD effect when the total infusion dose was ≤ 2 μg/kg. Moreover, DEX improved analgesia and sleep quality, provided appropriate sedation, and reduced the incidence of nausea, vomiting, and chills. The current evidence confirmed the prophylaxis and superiority of DEX for PPD. More high-quality, large-scale RCTs are required for verifying the reliability and formulating administration methods.

Melatonin vs. dexmedetomidine for sleep induction in children before electroencephalography

Background and objectives

In children requiring electroencephalography (EEG), sleep recording can provide crucial information. As EEG recordings during spontaneous sleep are not always possible, pharmacological sleep-inducing agents are sometimes required. The aim of the study was to evaluate safety and efficacy of melatonin (Mel) and dexmedetomidine (Dex; intranasal and sublingual application) for sleep induction prior to EEG.

Methods

In this prospective randomized study, 156 consecutive patients aged 1-19 years were enrolled and randomized by draw into melatonin group (Mel; n = 54; dose: 0.1 mg/kg), dexmedetomidine (Dex) sublingual group (DexL; n = 51; dose: 3 mcg/kg) or dexmedetomidine intranasal group (DexN; n = 51; dose: 3 mcg/kg). We compared the groups in several parameters regarding efficacy and safety and also carried out a separate analysis for a subgroup of patients with complex behavioral problems.

Results

Sleep was achieved in 93.6% of participants after the first application of the drug and in 99.4% after the application of another if needed. Mel was effective as the first drug in 83.3% and Dex in 99.0% (p < 0.001); in the subgroup of patients with complex developmental problems Mel was effective in 73.4% and Dex in 100% (p < 0.001). The patients fell asleep faster after intranasal application of Dex than after sublingual application (p = 0.006). None of the patients had respiratory depression, bradycardia, desaturation, or hypotension.

Conclusions

Mel and Dex are both safe for sleep induction prior to EEG recording in children. Dex is more effective compared to Mel in inducing sleep, also in the subgroup of children with complex behavioral problems.

Clinical Trial Registration

Dexmedetomidine and Melatonin for Sleep Induction for EEG in Children, NCT04665453.

Apnea during moderate to deep sedation using continuous infusion of remimazolam compared to propofol and dexmedetomidine: A retrospective observational study

Remimazolam's rapid onset and offset make it an innovative sedative for use during regional anesthesia. However, its respiratory safety profile is not well understood. We compared the continuous infusion of remimazolam with commonly used sedatives, propofol and dexmedetomidine, after regional anesthesia. In this retrospective study, the incidence of apnea (>10 seconds) was assessed in patients who underwent orthopedic surgery under regional anesthesia and received moderate to deep sedation using continuous infusion of remimazolam (group R: 0.1 mg/kg in 2 minutes followed by 0.5 mg/kg/hr). The incidence was compared with that of propofol (group P: 2-3 μg/mL target-controlled infusion) and dexmedetomidine (group D: 1 μg/kg in 10 minutes followed by 0.4-1 μg/kg/hr). Propensity score weighted multivariable logistic regression model was utilized to determine the effects of the sedative agents on the incidence of apnea. A total of 634 (191, 278, and 165 in group R, P, and D) cases were included in the final analysis. The incidence of apnea was 63.9%, 67.3%, and 48.5% in group R, P, and D, respectively. The adjusted odds ratios for apnea were 2.33 (95% CI, 1.50 to 3.61) and 2.50 (95% CI, 1.63 to 3.85) in group R and P, compared to group D. The incidence of apnea in patients receiving moderate to deep sedation using continuous infusion of remimazolam with dosage suggested in the current study was over 60%. Therefore, careful titration and respiratory monitoring is warranted.

Dexmedetomidine Prolongs Lidocaine Intravenous Regional Anesthesia in Rats by Blocking the Hyperpolarization-Activated Cation Current

Purpose

Intravenous regional anesthesia (IVRA) using lidocaine provides effective localized analgesia but its duration is limited. The mechanism by which dexmedetomidine enhances lidocaine IVRA is unclear but may involve modulation of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels.

Materials and Methods

Lidocaine IVRA with varying dexmedetomidine concentrations was performed in the tails of Sprague-Dawley rats. Tail-flick and tail-clamping tests assessed IVRA analgesia and anesthesia efficacy and duration. Contributions of α2 adrenergic receptors and HCN channels were evaluated by incorporating an α adrenergic receptor antagonist, the HCN channel inhibitor ZD7288, and the HCN channel agonist forskolin. Furthermore, whole-cell patch clamp electrophysiology quantified the effects of dexmedetomidine on HCN channels mediating hyperpolarization-activated cation current (Ih) in isolated dorsal root ganglion neurons.

Results

Dexmedetomidine dose-dependently extended lidocaine IVRA duration and analgesia, unaffected by α2 receptor blockade. The HCN channel inhibitor ZD7288 also prolonged lidocaine IVRA effects, while the HCN channel activator forskolin shortened effects. In dorsal root ganglion neurons, dexmedetomidine concentration-dependently inhibited Ih amplitude and shifted the voltage-dependence of HCN channel activation.

Conclusion

Dexmedetomidine prolongs lidocaine IVRA duration by directly inhibiting HCN channel activity, independent of α2 adrenergic receptor activation. This HCN channel inhibition represents a novel mechanism underlying the anesthetic and analgesic adjuvant effects of dexmedetomidine in IVRA.

Immunotherapeutic Properties of Dexmedetomidine on Pain Management and Cardiovascular Function in Videolaparoscopic Cholecystectomies: A Randomized, Two-Arm, Double-Blinded, Placebo-Controlled Trial

BACKGROUND

Laparoscopy represented one of the most innovative surgical techniques approached in the surgery field. Dexmedetomidine association with general anesthesia promotes the response control to trauma by altering the neuroinflammatory reflex, provides better clinical outcomes in the postoperative period and reduces the excessive use of drugs with risk for addiction. This trial aims to evaluate the potential drug treatment of dexmedetomidine on organic function, with the targets in neuroinflammation, perioperative pain control and blood pressure measurements in a medium-sized surgical model.

METHODS

Fifty-two patients were randomized in two groups: Sevoflurane and Dexmedetomidine - A (dexmedetomidine infusion [1 μg/kg loading, .2-.5 μg/kg/h thereafter]) vs Sevoflurane and Saline .9% - B. Three blood samples were collected at three times: before surgery, 4 to 6 hours after surgery and 24 hours postoperatively. The primary outcome was inflammatory and endocrine mediators dosage analisys. Finally, we evaluated pain and opioid use as secondary outcomes, also the hemodynamic values.

RESULTS

In Dexmedetomidine group A, a reduction of Interleukin 6 was found during 4-6 hours after surgery. A reduction of IL-10 was noted in the measurement of its values 24 hours after the procedure, with statistical significance. Also, systolic and diastolic blood pressure, as well heart rate were attenuated, and there was a lower incidence of pain and opioid consumption in the first postoperative hour (P < .0001) in the anesthetic recovery room.

CONCLUSIONS

Dexmedetomidine provided anti-inflammatory activity, sympatholytic effect and analgesia with cardiovascular safety. It reinforces the therapeutic nature of highly selective α2-adrenergic agonists when combined within anesthetic interventions.

Efficacy of adjuvant dexmedetomidine on penile block for pediatric hypospadias repair

INTRODUCTION

The management of postoperative pain, particularly in younger children, presents a challenge due to their limited ability to articulate the intensity of pain, lower pain threshold, and restricted availability of approved analgesics for pediatric use. Peripheral nerve blocks may be favored over neuraxial blocks because they allow quicker mobilization after surgery.

OBJECTIVE

The present study aims to investigate the potential impact of adding dexmedetomidine to a local anesthetic (bupivacaine) on the analgesic efficacy in dorsal penile nerve block in hypospadias repair surgery.

METHOD

In this prospective double-blinded clinical trial, 50 children aged between 6 months and 6 years old undergoing hypospadias repair surgery participated. Analgesia was administered through a dorsal penile nerve block (DPNB) at the end of surgery. Participants were divided into two groups; one received bupivacaine alone, and the other received dexmedetomidine and bupivacaine in DPNB. Pain and sedation levels were assessed with FLACC score and MOAA/S score, respectively, at 0,1,2 and 4 h after surgery. Vital signs and adverse effects were also recorded, including hemodynamic changes, nausea, and vomiting.

RESULT

There was no statistically significant difference in demographic variables. As illustrated in Figure, the median of FLACC score in group BD was significantly lower compared to group B at every measured time point. MOAA/S score was significantly lower in group BD than in group B (p < 0.001), indicating a higher sedation level. None of the participants in either group experienced any adverse effect except for vomiting, which was not statistically significant (8 % in group B vs. 4 % in group BD, p > 0.999).

DISCUSSION

Several studies have documented the supplementary analgesic properties of dexmedetomidine when used in conjunction with local anesthetic during various surgical procedures and nerve blocks. The present study provides evidence for the additional analgesic efficacy of dexmedetomidine and bupivacaine in the context of dorsal penile nerve block during hypospadias repair surgery while not yielding any significant adverse outcomes. Although the patients in our study were monitored for 4 h in the postanesthesia care unit (PACU), conducting a more comprehensive assessment of patients is advisable.

CONCLUSION

The findings of our study indicate that incorporating dexmedetomidine alongside bupivacaine in dorsal penile nerve block during hypospadias repair surgery may lead to enhanced management of postoperative pain. The lack of adverse effects implies it may be a potentially safe supplementary pain reliever for surgical procedures.

Association of Early Dexmedetomidine Utilization With Clinical and Functional Outcomes Following Moderate-Severe Traumatic Brain Injury: A Transforming Clinical Research and Knowledge in Traumatic Brain Injury Study

OBJECTIVE

To examine early sedation patterns, as well as the association of dexmedetomidine exposure, with clinical and functional outcomes among mechanically ventilated patients with moderate-severe traumatic brain injury (msTBI).

DESIGN

Retrospective cohort study with prospectively collected data.

SETTING

Eighteen Level-1 Trauma Centers, United States.

PATIENTS

Adult (age > 17) patients with msTBI (as defined by Glasgow Coma Scale < 13) who required mechanical ventilation from the Transforming Clinical Research and Knowledge in TBI (TRACK-TBI) study.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Using propensity-weighted models, we examined the association of early dexmedetomidine exposure (within the first 5 d of ICU admission) with the primary outcome of 6-month Glasgow Outcomes Scale Extended (GOS-E) and the following secondary outcomes: length of hospital stay, hospital mortality, 6-month Disability Rating Scale (DRS), and 6-month mortality. The study population included 352 subjects who required mechanical ventilation within 24 hours of admission. The initial sedative medication was propofol for 240 patients (68%), midazolam for 59 patients (17%), ketamine for 6 patients (2%), dexmedetomidine for 3 patients (1%), and 43 patients (12%) never received continuous sedation. Early dexmedetomidine was administered in 77 of the patients (22%), usually as a second-line agent. Compared with unexposed patients, early dexmedetomidine exposure was not associated with better 6-month GOS-E (weighted odds ratio [OR] = 1.48; 95% CI, 0.98-2.25). Early dexmedetomidine exposure was associated with lower DRS (weighted OR = -3.04; 95% CI, -5.88 to -0.21). In patients requiring ICP monitoring within the first 24 hours of admission, early dexmedetomidine exposure was associated with higher 6-month GOS-E score (OR 2.17; 95% CI, 1.24-3.80), lower DRS score (adjusted mean difference, -5.81; 95% CI, -9.38 to 2.25), and reduced length of hospital stay (hazard ratio = 1.50; 95% CI, 1.02-2.20).

CONCLUSION

Variation exists in early sedation choice among mechanically ventilated patients with msTBI. Early dexmedetomidine exposure was not associated with improved 6-month functional outcomes in the entire population, although may have clinical benefit in patients with indications for ICP monitoring.

Safety and efficacy of dexmedetomidine vs. midazolam in complex gastrointestinal endoscopy: A systematic review and meta-analysis

OBJECTIVE

This study aims to perform a meta-analysis to evaluate the safety and efficacy of dexmedetomidine versus midazolam for complex digestive endoscopy procedures, with the goal of offering comprehensive clinical evidence.

METHODS

Following predefined inclusion criteria, five databases were systematically searched, with a focus on identifying randomized controlled trials (RCTs) that compared the administration of dexmedetomidine and midazolam during complex digestive endoscopy procedures. The statistical software Stata 15.1 was employed for meticulous data analysis.

RESULTS

Sixteen RCTs were encompassed, involving a total of 1218 patients. In comparison to the midazolam group, dexmedetomidine administration was associated with a reduced risk of respiratory depression (RR=0.25, 95 %CI: 0.11-0.56) and hypoxemia (RR=0.22, 95 %CI: 0.12-0.39). Additionally, the dexmedetomidine group exhibited lower incidence rates of choking (RR=0.27, 95 %CI: 0.16-0.47), physical movement (RR=0.16, 95 %CI: 0.09-0.27), and postoperative nausea and vomiting (RR=0.56,95 %CI: 0.34-0.92). Patients and endoscopists in the dexmedetomidine group reported higher levels of satisfaction (patient satisfaction: SMD=0.73, 95 %CI: 0.26-1.21; endoscopist satisfaction: SMD=0.84, 95 %CI: 0.24-1.44). The incidence of hypotension and anesthesia recovery time did not significantly differ between the two groups (hypotension: RR=1.73,95 %CI:0.94-3.20; anesthesia recovery time: SMD=0.02, 95 %Cl: 0.44-0.49). It is noteworthy that the administration of dexmedetomidine was associated with a significant increase in the incidence of bradycardia in patients.

CONCLUSION

Compared to midazolam, dexmedetomidine exhibits a favorable safety profile for use in complex gastrointestinal endoscopy by significantly reducing the risk of respiratory depression and hypoxemia. Despite this, dexmedetomidine is associated with a higher incidence of bradycardia. These findings underscore the need for further research through larger, multi-center studies to thoroughly investigate dexmedetomidine's safety and efficacy.

Effect of Intraperitoneal Instillation of Dexmedetomidine With Local Anesthetics in Laparoscopic Cholecystectomy: A Systematic Review and Meta-analysis of Randomized Trials

OBJECTIVE

Dexmedetomidine (DEX) can strengthen the analgesic effects of local anesthetics (LAs) when used as an adjuvant through intrathecal, perineural, and intraperitoneal routes. Many studies have used intraperitoneal instillation of DEX with LAs in laparoscopic cholecystectomy (LC) to relieve postoperative pain. We performed a systematic review and meta-analysis to synthesize evidence of the efficacy and safety of intraperitoneal instillation of DEX as an adjuvant of LAs in patients undergoing LC.

METHODS

A comprehensive literature search of the MEDLINE, PubMed, EMBASE, and Cochrane Library databases was performed to identify randomized controlled trials in which patients received intraperitoneal instillation of DEX combined with LAs during LC. A meta-analysis and sensitivity analysis of the results were conducted. We also performed a subgroup analysis to investigate the source of heterogeneity. The Egger test was used to check for publication bias.

RESULTS

Eleven randomized controlled trials involving 890 patients were analyzed. We found that the addition of DEX to LAs significantly decreased pain scores at six postoperative time points (0.5, 1, 2, 4, 12, and 24 h) and significantly prolonged the time to the first analgesic request by patients. In addition, 24-hour postoperative analgesic consumption was decreased in the experimental group, and no significant difference in the incidence of nausea and vomiting was observed.

CONCLUSION

Our findings indicate that intraperitoneal instillation of DEX with LAs can reduce postoperative pain and prolong the time to first request analgesia after LC.

Dexmedetomidine for Preventing Sleep Disturbance after Ambulatory Anesthesia: A Case Report

Propofol anesthesia may impact a patient's sleep quality in the immediate postprocedure timeframe. We describe a 24-year-old man presenting for gastrostomy-jejunostomy tube replacement who reported debilitating sleep-onset disturbances after 3 previous anesthetic exposures for the same procedure. Review of the patient's records revealed the recurring use of propofol infusion. We proposed using dexmedetomidine infusion to potentially avoid another extended sleep disturbance. Following a dexmedetomidine-centered plan, the patient reported experiencing his usual sleep pattern without side-effects for 5 consecutive days postprocedure. This case highlights the potential for propofol-induced sleep disturbance in the ambulatory setting, which may be avoided with dexmedetomidine administration.

Dexmedetomidine as an effective alternative tool for heart rate control in atrial fibrillation during general anesthesia-A case report

Atrial fibrillation (AF) is a common arrhythmia requiring effective heart rate (HR) management. Conventional therapies may not always achieve the desired HR control during intraoperative conditions. We present two cases of AF patients in whom dexmedetomidine, an alpha-2 receptor agonist, was utilized during surgery when conventional treatments proved ineffective. In Case 1, a 65-year-old male with multiple comorbidities underwent surgery. Despite receiving intraoperative medications for AF, his HR remained uncontrolled. Dexmedetomidine successfully stabilized his HR without complications. In Case 2, a 75-year-old male with heart disease experienced a sudden HR surge during surgery, which remained uncontrolled despite conventional treatment. Dexmedetomidine effectively managed his HR, ensuring a safer surgical course. While the primary indication of dexmedetomidine is not arrhythmia management, this case report suggests its potential in challenging cases. Further research is needed to explore its therapeutic role in tachyarrhythmia management and establish appropriate dosing strategies.

Impact of intravenous dexmedetomidine on postoperative gastrointestinal function recovery: an updated meta-analysis

BACKGROUND

Postoperative ileus (POI) is a complication that may occur after abdominal or nonabdominal surgery. Intravenous dexmedetomidine (Dex) has been reported to accelerate postoperative gastrointestinal function recovery; however, updated evidence is required to confirm its robustness.

METHODS

To identify randomized controlled trials examining the effects of perioperative intravenous Dex on gastrointestinal function recovery in patients undergoing noncardiac surgery, databases including MEDLINE, EMBASE, Google Scholar, and Cochrane Library were searched on August 2023. The primary outcome was time to first flatus. Secondary outcomes included time to oral intake and defecation as well as postoperative pain scores, postoperative nausea/vomiting (PONV), risk of hemodynamic instability, and length of hospital stay (LOS). To confirm its robustness, subgroup analyses and trial sequential analysis were performed.

RESULTS

The meta-analysis of 22 randomized controlled trials with 2566 patients showed that Dex significantly reduced the time to flatus [mean difference (MD):-7.19 h, P <0.00001), time to oral intake (MD: -6.44 h, P =0.001), time to defecation (MD:-13.84 h, P =0.008), LOS (MD:-1.08 days, P <0.0001), and PONV risk (risk ratio: 0.61, P <0.00001) without differences in hemodynamic stability and pain severity compared with the control group. Trial sequential analysis supported sufficient evidence favoring Dex for accelerating bowel function. Subgroup analyses confirmed the positive impact of Dex on the time to flatus across different surgical categories and sexes. However, this benefit has not been observed in studies conducted in regions outside China.

CONCLUSIONS

Perioperative intravenous Dex may enhance postoperative gastrointestinal function recovery and reduce LOS, thereby validating its use in patients for whom postoperative ileus is a significant concern.

Microglial Nrf2/HO-1 signaling gates remifentanil-induced hyperalgesia via suppressing TRPV4-mediated M1 polarization

Remifentanil-induced hyperalgesia (RIH) represents a significant clinical challenge due to the widespread use of opioids in pain management. However, the molecular and cellular mechanisms underlying RIH remain elusive. This study aimed to unravel the role of spinal cord microglia, focusing on the Nrf2/HO-1 signaling pathway and TRPV4 channels in the development of RIH. We used both in vivo and in vitro models to investigate the activation state of spinal cord microglia, the expression of TRPV4 channels, and the modulation of the Nrf2/HO-1 pathway under remifentanil exposure. In addition, we evaluated the potential therapeutic effects of dexmedetomidine, a perioperative α2-adrenergic agonist, on RIH and its related molecular pathways. Our results revealed a prominent role of spinal cord microglia in RIH, demonstrating an apparent microglial M1 polarization and increased TRPV4 channel expression. A notable observation was the downregulation of the Nrf2/HO-1 pathway, which was associated with increased neuroinflammation and mechanical allodynia. By upregulating or overexpressing Nrf2, we confirmed its ability to inhibit TRPV4 and thereby attenuate RIH-associated mechanical allodynia, M1 polarization, and neuroinflammation. Encouragingly, dexmedetomidine demonstrated therapeutic potential by positively modulating the Nrf2-TRPV4 nexus, attenuating mechanical allodynia, and reducing microglial inflammation. Our research highlights the critical role of spinal cord microglia in RIH mediated by the Nrf2-TRPV4 axis. The ability of dexmedetomidine to modulate this axis suggests its potential as an adjunctive therapy to remifentanil in mitigating RIH. Further studies are imperative to explore the broader implications and practical applicability of our findings.

The Anesthetic Complexity of Eisenmenger Syndrome: A Clinical Case

Eisenmenger syndrome (ES) is a complex, multisystemic, and rare clinical entity, given that currently, most congenital heart diseases can be corrected in childhood. The high anesthetic risk in these patients poses a challenge for anesthesiology. There are few cases described in the literature of anesthetic approaches using ketamine and dexmedetomidine in ES cases, particularly under Monitored Anesthesia Care (MAC). We describe the clinical case of a 40-year-old patient with trisomy 21, intellectual disability, and ES secondary to a single atrioventricular (AV) valve, scheduled for cranial magnetic resonance imaging (MRI) under sedation due to a suspected space-occupying lesion. Sedation was performed under MAC with dexmedetomidine and ketamine. The procedure proceeded without complications. The anesthetic approach in ES patients, given the clinical complexity, requires planning by a multidisciplinary team and should be tailored to the procedure and its duration.

Sedation with propofol/remifentanil versus dexmedetomidine / remifentanil for patients undergoing transcatheter aortic valve implant: A retrospective study between 2012 and 2019

BACKGROUND AND OBJECTIVES

Percutaneous implantation of an aortic valve prosthesis is a therapeutic alternative for patients with severe aortic stenosis. The procedure is traditionally performed under general anaesthesia; however, sedation is now gaining in popularity because it reduces the need for vasoactive drugs and shortens the patient's stay in the critical care unit and on the ward. The aim of this study is to evaluate the clinical efficacy, safety and potential benefits of sedation with dexmedetomidine in patients undergoing percutaneous implantation of an aortic valve prosthesis in terms of haemodynamic and respiratory complications.

MATERIALS AND METHODS

We performed a retrospective study of 222 patients that had undergone percutaneous implantation of an aortic valve prosthesis between 2012 and 2019 under sedation with either dexmedetomidine plus remifentanil (DEX-RMF) or propofol plus remifentanil (PROPO-RMF). We collected data on complications, mainly haemodynamic and respiratory, during and after the procedure.

RESULTS

No significant differences were found between sedation with dexmedetomidine and propofol (in combination with remifentanil) in terms of haemodynamic stability and intraprocedural cerebral blood oxygen. In the DEX-RMF group, however, mean blood pressure, midazolam dose, and duration of anaesthesia were lower compared with the PROPO-RMF group, but the incidence of haemodynamic and respiratory complications did not differ significantly between groups.

CONCLUSIONS

Our results show that sedation, particularly with adjuvant dexmedetomidine, is a valid anaesthetic techniques in percutaneous aortic valve prosthesis implantation.

Retrospective Analysis of Perioperative Dexmedetomidine Use in Retina Surgeries: Impact on Postanesthesia Care

BACKGROUND AND OBJECTIVE

Dexmedetomidine (Precedex®) has been linked to depressive hemodynamic effects and increased length of stay in the post-anesthesia care unit (PACU) when used in ambulatory phacoemulsification procedures. We aimed to determine the prevalence and impact of dexmedetomidine use during ambulatory vitreoretinal procedures.

PATIENTS AND METHODS

This retrospective cohort study involved 9,666 adult vitrectomies. Cases were divided into groups by anesthesia type: general anesthesia (GA) and monitored anesthesia care (MAC). For each group, various factors were compared between those who did and did not receive dexmedetomidine. Chi-squared and t tests were used for comparisons.

RESULTS

Changes in mean arterial pressure in the MAC group were -1.69 ± 0.23 mmHg for no dexmedetomidine patients and -6.31 ± 0.39 mmHg for dexmedetomidine patients (P < 0.01). In the GA group, mean arterial pressure was -6.1 ± 0.35 mmHg for no dexmedetomidine patients and -11.18 ± 0.88 mmHg for dexmedetomidine patients (P < 0.01). PACU Phase II time in the MAC group was 36.93 ± 0.37 minutes and 40.67 ± 0.86 minutes for no dexmedetomidine and dexmedetomidine patients, respectively (P < 0.01). In the GA group, PACU Phase II time was 58.63 ± 0.95 minutes and 65.19 ± 2.38 minutes for no dexmedetomidine and dexmedetomidine patients, respectively (P < 0.01).

CONCLUSIONS

Dexmedetomidine use in vitrectomies was associated with significant PACU delays. These delays may stem from adverse hemodynamic effects. [Ophthalmic Surg Lasers Imaging Retina 2024;55:86-91.].

Regional versus systemic dexmedetomidine as an adjuvant to lidocaine for intravenous regional anaesthesia in healthy volunteers: a randomized crossover study

BACKGROUND

Dexmedetomidine enhances the quality and duration of lidocaine intravenous regional anaesthesia (IVRA). However, the two administration routes have not been directly compared regarding effects on tourniquet tolerance time with lidocaine IVRA. Additionally, it remains unclear whether the prolonged tourniquet tolerance stems from the direct peripheral action of dexmedetomidine or indirect systemic analgesic effects.

METHODS

We conducted forearm IVRA in 12 healthy volunteers using a crossover design on two separate study days. One day, the systemic dexmedetomidine group received an intravenous infusion of 0.5 μg/kg dexmedetomidine (20 mL) in one arm, followed by 0.5% lidocaine (25 mL) forearm IVRA in the contralateral arm. On the other day, the regional dexmedetomidine group received an intravenous 0.9% saline infusion (20 mL) in one arm, followed by combined 0.5% lidocaine (25 mL) and 0.5 μg/kg dexmedetomidine forearm IVRA in the opposite arm. After a two-week washout period, participants crossed over to receive the alternate treatment. The primary outcome was tourniquet tolerance time, from initiating IVRA until the patient-reported tourniquet pain numerical rating scale exceeded three.

RESULTS

The tourniquet tolerance time was longer with regional versus systemic dexmedetomidine (36.9 ± 7.6 min vs 23.3 ± 6.2 min, respectively), with a 13.6 min mean difference (95% CI: 10.8 to 16.4 min, p < 0.001). Regional dexmedetomidine also hastened sensory onset and extended sensory recovery compared to systemic administration. Delayed sedation after tourniquet release occurred in 5 of 12 subjects receiving regional dexmedetomidine.

CONCLUSION

The addition of regional dexmedetomidine to lidocaine prolonged tourniquet tolerance time in forearm IVRA to a greater extent compared to systemic dexmedetomidine in healthy volunteers.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR2300067978.

An Investigation into the Effects of Chemical, Pharmaceutical, and Herbal Compounds on Neuroglobin: A Literature Review

Neuroglobin (Ngb) is an oxygen-binding globin protein that is mainly expressed in the neurons of the central and peripheral nervous system. However, moderate levels of Ngb have also been detected in non-neural tissues. Ngb and Ngb modulating factors have been increasingly studied over the last decade due to their neuroprotective role in neurological disorders and hypoxia. Studies have shown that a number of chemicals, pharmaceuticals, and herbal compounds can modulate the expression of Ngb at different dose levels, indicating a protective role against neurodegenerative diseases. Iron chelators, hormones, antidiabetic drugs, anticoagulants, antidepressants, plant derivatives and short-chain fatty acids are among these compounds. Therefore, this study aimed to review the literature focused on the possible effects and mechanisms of chemical, pharmaceutical, and herbal compounds on Ngbs.

Sigma-1 receptor regulates the endoplasmic reticulum stress pathway in the protective mechanism of dexmedetomidine against hyperoxia-induced lung injury

Perioperative hyperoxia therapy is of great significance to save the lives of patients, but little is known about the possible mechanisms that induce hyperoxia-induced acute lung injury (HALI) and the measures for clinical prevention and treatment. In this experiment, the models were established with a feeding chamber with automatic regulation of oxygen concentration. The results showed that with the increase in inhaled oxygen concentration and the prolongation of exposure time, the severity of lung injury also increases significantly, reaching the diagnostic indication of HALI after 48 h of inhaling 95 % oxygen concentration. Subsequently, according to the dynamic changes of apoptosis in lung specimens, and the expression changes in Sig-1R-regulated ER stress pathway proteins (Sig-1R, GRP78, p-PERK, ATF6, IRE1, Caspase-12, ATF4, CHOP, Caspase-3 and p-JNK), it was confirmed that the Sig-1R-regulated ER stress signaling pathway was involved in the occurrence of HALI. To explore the preventive and therapeutic effects of routine clinical medication on HALI during the perioperative period, our research group selected dexmedetomidine (Dex) with lung protection. The experimental results revealed that Dex partially reversed the changes in the expression levels of Sig-1R-regulated ER stress pathway proteins. These results preliminarily confirmed that Dex may inhibit apoptosis induced by high oxygen concentration through the Sig-1R-regulated ER stress signaling pathway, thus playing a protective role in HALI.

Adrenoceptors: Receptors, Ligands and Their Clinical Uses, Molecular Pharmacology and Assays

The nine G protein-coupled adrenoceptor subtypes are where the endogenous catecholamines adrenaline and noradrenaline interact with cells. Since they are important therapeutic targets, over a century of effort has been put into developing drugs that modify their activity. This chapter provides an outline of how we have arrived at current knowledge of the receptors, their physiological roles and the methods used to develop ligands. Initial studies in vivo and in vitro with isolated organs and tissues progressed to cell-based techniques and the use of cloned adrenoceptor subtypes together with high-throughput assays that allow close examination of receptors and their signalling pathways. The crystal structures of many of the adrenoceptor subtypes have now been determined opening up new possibilities for drug development.

Effect of ultrasound-guided femoral nerve block with dexmedetomidine and ropivacaine on postoperative analgesia in patients undergoing total knee arthroplasty: a randomized controlled trial

Background

Dexmedetomidine, a potent and highly selective α2-adrenoreceptor agonist, has become a popular adjuvant to local anesthetics. This study was designed to investigate the effect of dexmedetomidine with ropivacaine for femoral nerve block on postoperative analgesia after total knee arthroplasty.

Methods

Forty-six patients after total knee arthroplasty received ultrasound-guided femoral nerve block with either 0.3% ropivacaine alone (group R) or 0.3% ropivacaine with 0.5 μg/kg dexmedetomidine (group RD). Total 24-h sufentanil consumption, visual analogue scale (VAS) pain scores, frequency of patient-controlled analgesia (PCA) pressed, Ramsay sedation score, the incidence of bradycardia and hypotension, and incidence of postoperative nausea and vomiting (PONV) were recorded.

Results

Compared to group R, the total 24-h sufentanil consumption was significantly reduced (110.76 ± 11.56 vs. 99.09 ± 13.31; P<0.05), the VAS scores were lower at 10 and 12 h postoperatively [3(2-3) vs. 2(1-2) and 3(2-3) vs. 2(1-3), respectively; P<0.05], the frequency of PCA pressed was lower at 8-12 and 12-16-h time intervals [(5(3-6) vs. 2(1-3) and 4(3-4) vs. 2(1-3), respectively; P<0.05]. However, there were no differences in Ramsay's sedation score and the incidence of PONV. Also, no patient experienced bradycardia and hypotension.

Conclusions

0.5 μg/kg dexmedetomidine with 0.3% ropivacaine for femoral nerve block significantly decreased the total 24-h sufentanil consumption, prolonged and enhanced the analgesic efficacy of ropivacaine, without clinically relevant cardiovascular depression or over-sedation in patients undergoing total knee arthroplasty.

Efficacy of ultrasound guided superior laryngeal nerve block on sedation for delayed extubation in maxillofacial surgery with free flap reconstruction

OBJECTIVE

Superior laryngeal nerve block (SLNB) is a regional anesthesia technique for addressing airway response. However, SLNB on the efficacy of sedation in patients with delayed extubation is unknown, particularly for maxillofacial surgery (MS). The aim of the study was to assess whether ultrasound guided (UG) SLNB reduces the incidence of moderate to severe cough for delayed extubation in MS with free flap reconstruction.

METHODS

60 patients were randomly assigned to the GEA group (control group) and the SLNB group (UG-SLNB postoperatively, study group). During the initial two postoperative hours, the incidence of moderate and severe cough, agitation, and the number of patients requiring rescue propofol and flurbiprofen were recorded. Additionally, the time spent under the target level of sedation, postoperative hemodynamics, and the total does of propofol during the postoperative 24 h were recorded.

RESULTS

The data showed the SLNB group had a significantly lower incidence of moderate to severe cough and agitation (p < 0.05), and a longer sedation time (p < 0.05). The number of patients required rescue propofol and flurbiprofen, as well as the hemodynamic changes, were significantly different between the two groups (p < 0.05).

CONCLUSION

The use of UG-SLNB is associated with reduced incidence of postoperative cough. Moreover, SLNB can enhance the efficacy of postoperative sedation with need of fewer agents postoperatively.

CLINICAL TRIAL REGISTRATION

ChiCTR2000039982.

Perioperative Hypotension in Patients Undergoing Orthopedic Upper Extremity Surgery with Dexmedetomidine Sedation: A Retrospective Study

(1) Background: limited data exist regarding the occurrence of hypotension associated with dexmedetomidine use and its risk factors in the context of intraoperative sedation for patients receiving peripheral nerve blocks. (2) Method: This single-center retrospective study assessed the incidence of hypotension in patients undergoing orthopedic upper extremity surgery with brachial plexus blockade. Patients were classified into three groups: group N (non-sedated), group M (midazolam), and group D (dexmedetomidine), based on their primary intraoperative sedative use. The primary outcome was the incidence of perioperative hypotension, defined as systolic blood pressure (SBP) < 90 mmHg or mean blood pressure (MBP) < 60 mmHg, at a minimum of two recorded time points during the intraoperative period and post-anesthesia care unit stay. Multivariable logistic models for the occurrence of hypotension were constructed for the entire cohort and group D. (3) Results: A total of 2152 cases (group N = 445, group M = 678, group D = 1029) were included in the analysis. The odds ratio for the occurrence of hypotension in group D was 5.68 (95% CI, 2.86 to 11.28) compared with group N. Concurrent use of a beta blocker, longer duration of surgery, and lower preoperative SBP and higher preoperative heart rate were identified as significant risk factors. (4) Conclusions: the increased risk of hypotension and the associated factors should be taken into account before using dexmedetomidine in these cases.

Effect of pre-use of Dexmedetomidine on the effective inhibitory dose of remimazolam tosilate on positive cardiovascular response in double-lumen endobronchial intubation: a clinical study

BACKGROUND

Herein, the effect of pre-use of Dexmedetomidine(Dex) on the half-effective dose (ED50) and 95%-effective dose (ED95) of Remimazolam tosilate(RT) in inhibiting the positive cardiovascular response(CR) which means blood pressure or heart rate rises above a critical threshold induced by double-lumen bronchial intubation was evaluated.

METHODS

Patients who underwent video-assisted thoracic surgery were divided into groups A (0), B (0.5 µg/kg), and C (1 µg/kg) based on different Dex doses. Group A included subgroups comprising young (A-Y) and elderly (A-O) patients. Neither groups B nor C included elderly patients due of the sedative effect of Dex. Based on the previous subject's CR, the dose of RT was increased or decreased in the next patient using the sequential method. This trial would be terminated when the seventh crossover occurred, at which point the sample size met the stable estimate of the target dose. Heart rate (HR) and mean arterial pressure (MAP) were monitored throughout the trial, and sedation was assessed using the Modified Observer's Assessment of Alertness/Sedation (MOAA/S) scale. HR and MAP were recorded at baseline (T1), the end of Dex (T2), and the end of RT (T3), the maximum HR and MAP were recorded within 3 min of intubation from beginning to end (T4). There was a positive CR when the T4 levels rose above 15% of the baseline. The ED50/ED95 and corresponding confidence interval were calculated using probability regression.

RESULTS

In total, 114 patients completed the trial. Without the use of Dex, the ED50/ED95 of TR inhibiting the positive CR caused by double-lumen bronchial intubation was 0.198/0.227 and 0.155/0.181 mg/kg in groups A-Y and A-O, respectively. The changes in vital signs from T1 to T3 were similar in the subgroups, indicating that the elderly patients were more sensitive to the dose of RT. The ED50/ED95 of RT inhibiting the positive CR caused by double-lumen endobronchial intubation was 0.122/0.150 and 0.068/0.084 mg/kg in groups B and C, respectively. And, the fluctuation of blood pressure from T3 to T4 was reduced by using Dex. RT was 100% effective in sedation with no significant inhibition of circulation. Apart from one case of hypotension occurred in group A-Y, two cases of low HR in group B, and one case of low HR in group C, no other adverse events were noted.

CONCLUSIONS

The optimal dose of RT to inhibit positive CR induced by double-lumen bronchial intubation in elderly patients was 0.18 mg/kg and 0.23 mg/kg in younger patients. When the pre-use dose of Dex was 0.5 µg/kg, the optimal dose to inhibit positive CR of RT was 0.15 mg/kg. And, when the pre-use dose of Dex was 1 µg/kg, the optimal dose of RT was 0.9 mg/kg.

CLINICAL TRIAL REGISTRATION

NCT05631028.

Comparison of oxygen reserve index according to the remimazolam or dexmedetomidine for intraoperative sedation under regional anesthesia-A single-blind randomized controlled trial

Introduction

We aimed to evaluate the difference in intraoperative oxygen reserve index (ORi) between the sedatives remimazolam (RMMZ) and dexmedetomidine (DEX).

Methods

Seventy-eight adult patients scheduled for sedation under regional anesthesia were randomly assigned to either the DEX (n = 39) or RMMZ (n = 39) group. The primary outcome was the difference in perioperative ORi between the groups. The secondary outcomes included respiratory depression, hypo- or hypertension, heart rate (HR), blood pressure, respiratory rate and postoperative outcomes. Additionally, the number of patients who experienced a decrease in intraoperative ORi to < 50% and the associated factors were analyzed.

Results

The ORi was significantly higher in the RMMZ group at 15 min after sedation maintenance. There were no significant differences in respiratory depression between the two groups. The intraoperative HR was significantly higher in the RMMZ group after the induction of sedation, 15 min after sedation maintenance, and at the end of surgery. No other results were significantly different between the two groups. The incidence of a decrease in intraoperative ORi to < 50% was significantly higher in the DEX group. Factors associated with a decrease in the intraoperative ORi to < 50% were diabetes mellitus, low baseline peripheral oxygen saturation (SpO2), and DEX use. In the receiver operating characteristic curve analysis for a decrease in the intraoperative ORi to < 50%, the cutoff baseline SpO2 was 97%.

Conclusion

RMMZ is recommended as a sedative for patients with a low baseline SpO2 and intraoperative bradycardia. Further studies should be conducted to establish the criteria for a significant ORi reduction.