A Comparative Study of the Antiemetic Effects of α2-Adrenergic Receptor Agonists Clonidine and Dexmedetomidine against Diverse Emetogens in the Least Shrew (Cryptotis parva) Model of Emesis.

In contrast to cats and dogs, here we report that the α2-adrenergic receptor antagonist yohimbine is emetic and corresponding agonists clonidine and dexmedetomidine behave as antiemetics in the least shrew model of vomiting. Yohimbine (0, 0.5, 0.75, 1, 1.5, 2, and 3 mg/kg, i.p.) caused vomiting in shrews in a bell-shaped and dose-dependent manner, with a maximum frequency (0.85 ± 0.22) at 1 mg/kg, which was accompanied by a key central contribution as indicated by increased expression of c-fos, serotonin and substance P release in the shrew brainstem emetic nuclei. Our comparative study in shrews demonstrates that clonidine (0, 0.1, 1, 5, and 10 mg/kg, i.p.) and dexmedetomidine (0, 0.01, 0.05, and 0.1 mg/kg, i.p.) not only suppress yohimbine (1 mg/kg, i.p.)-evoked vomiting in a dose-dependent manner, but also display broad-spectrum antiemetic effects against diverse well-known emetogens, including 2-Methyl-5-HT, GR73632, McN-A-343, quinpirole, FPL64176, SR141716A, thapsigargin, rolipram, and ZD7288. The antiemetic inhibitory ID50 values of dexmedetomidine against the evoked emetogens are much lower than those of clonidine. At its antiemetic doses, clonidine decreased shrews' locomotor activity parameters (distance moved and rearing), whereas dexmedetomidine did not do so. The results suggest that dexmedetomidine represents a better candidate for antiemetic potential with advantages over clonidine.

Safety and efficacy of dexmedetomidine in combination with local anesthetics for orthopedic nerve blocks: a systematic review and meta-analysis.

INTRODUCTION: Peripheral nerve block, a common technique for managing postoperative pain and providing intraoperative analgesia, often includes adjuncts like dexmedetomidine (DEX) to enhance the effectiveness of local anesthetics. DEX, known for its α2-adrenoceptor agonist properties, extends sensory blockade and improves postoperative analgesia while offering sedative benefits. The objective of this study is to rigorously assess the effectiveness and safety of perineural DEX injection in orthopedic nerve block procedures, focusing on orthopedic surgeries to minimize heterogeneity and provide clearer insights for clinical practice. EVIDENCE ACQUISITION: This meta-analysis, registered on PROSPERO, involved a comprehensive literature search across multiple databases, focusing on RCTs comparing DEX with local anesthetics for peripheral nerve blocks in orthopedic surgery patients. The eligibility criteria included adult participants and various nerve block methods in orthopedic surgeries. Studies were rigorously appraised for methodological quality using Cochrane Handbook guidelines. GRADE profiler 3.6 was used for evidence grading. EVIDENCE SYNTHESIS: Among 1391 documents, 21 studies were included, focusing on DEX with local anesthetics in orthopedic nerve blocks. Findings showed significant improvements in analgesia duration, sensory and motor block duration, and reduced postoperative opioid consumption, with an increased risk of bradycardia. Quality assessments indicated moderate bias risk. CONCLUSIONS: DEX with local anesthetics significantly enhances nerve block effectiveness, extending analgesia and block durations while reducing opioid need. However, it requires careful monitoring due to increased bradycardia risk. These findings highlight the need for cautious use in clinical practice, considering both potential benefits and adverse effects.

Impact of intraoperative dexmedetomidine on postoperative delirium and pro-inflammatory cytokine levels in elderly patients undergoing thoracolumbar compression fracture surgery: A prospective, randomized, placebo-controlled clinical trial.

BACKGROUND: This study evaluates the efficacy of dexmedetomidine (DEX) in reducing postoperative delirium (POD) and modulating pro-inflammatory cytokines in elderly patients undergoing thoracolumbar compression fracture surgery. METHODS: In this randomized, double-blind, placebo-controlled trial conducted from October 2022 to January 2023 at Anting Hospital in Shanghai, 218 elderly patients were randomized into DEX (n = 110) and normal saline (NS, n = 108) groups. The DEX group received 0.5 µg/kg/h DEX, and delirium incidence was assessed using the Confusion Assessment Method (CAM) on days 1 to 3 post-surgery. Levels of interleukins IL-1ß, IL-6, and tumor necrosis factor-α (TNF-α) were measured pre-operation (T0) and on postoperative days 1 (T1) and 3 (T3). Preoperative (T0) and postoperative day 1 (T1) cerebrospinal fluid (CSF) samples were treated with varying concentrations of olanzapine or DEX to observe their regulatory effects on the expression of Phospho-ERK1/2 and Phospho-JNK. RESULTS: Dexmedetomidine significantly lowered the incidence of POD to 18.2%, compared to 30.6% in the NS group (P = .033). While all patients showed an initial increase in cytokine levels after surgery, by T3, IL-6 and TNF-α levels notably decreased in the DEX group, with no significant change in IL-1ß levels across groups. The adverse events rate was similar between groups, demonstrating the safety of DEX in this population. In postoperative CSF samples, treatment with 0.5 mM DEX significantly downregulated Phospho-JNK and upregulated Phospho-ERK1/2 expression, demonstrating a dose-dependent modulation of inflammatory responses. CONCLUSION: Dexmedetomidine is effective in reducing early POD in elderly patients post-thoracolumbar compression fracture surgery. It also decreases IL-6 and TNF-α levels, indicating its potential in managing postoperative inflammatory responses. Treatment with 0.5 mM DEX significantly modulated Phospho-ERK1/2 and Phospho-JNK expressions in postoperative CSF samples, indicating a dose-dependent effect on reducing inflammation. This study contributes to understanding DEX's role in improving postoperative outcomes in elderly patients.

Effect of Intravenous Dexmedetomidine Before Extubation on Emergence Delirium after Nasal Surgeries.

OBJECTIVE: To investigate the role of single dose of dexmedetomidine (0.5 mcg/kg) in reducing the incidence and severity of postoperative emergence delirium (EmD). STUDY DESIGN: A randomised controlled trial. Place and Duration of the Study: Department of Anaesthesia, Security Forces Hospital, Riyadh, Saudi Arabia, from 1st December 2022 to 30th March 2023. METHODOLOGY: Patients, aged between 18-65 years, with ASA 1-3 scheduled to undergo nasal surgeries under general anaesthesia, were inducted in the study. Exclusion criteria were patient refusal, later request for removal from the study, inability to give consent, known allergy to dexmedetomidine, body mass index (BMI) more than 35, history of obstructive sleep apnoea, history of psychiatric illness, pregnancy, and presence of liver and renal diseases. The primary outcome measure of the study was the incidence of emergence delirium in the postoperative period. RESULTS: The frequency of EmD after nasal surgery was 52.38% in the control group compared to 14.28% in the dexmedetomidine group (p = 0.01). Pain scores were not statistically different between the two groups. The duration of post anaesthesia care unit (PACU) stay was significantly lesser in dexmedetomidine group (p <0.001). The satisfaction score on the visual analogue scale (VAS) was also found to be higher in patients who received intravenous dexmedetomidine (p <0.001). CONCLUSION: The use of single dose dexmedetomidine before extubation in nasal surgeries reduces the EmD and improves patient satisfaction. KEY WORDS: Dexmedetomidine, Emergence delirium, Nasal surgery, Opioid consumption, Pain control.

Dexmedetomidine for analgesia and sedation in newborn infants receiving mechanical ventilation.

BACKGROUND: Dexmedetomidine is a selective alpha-2 agonist with minimal impact on the haemodynamic profile. It is thought to be safer than morphine or stronger opioids, which are drugs currently used for analgesia and sedation in newborn infants. Dexmedetomidine is increasingly being used in children and infants despite not being licenced for analgesia in this group. OBJECTIVES: To determine the overall effectiveness and safety of dexmedetomidine for sedation and analgesia in newborn infants receiving mechanical ventilation compared with other non-opioids, opioids, or placebo. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, CINAHL, and two trial registries in September 2023. SELECTION CRITERIA: We planned to include randomised controlled trials (RCTs) and quasi-RCTs evaluating the effectiveness of dexmedetomidine compared with other non-opioids, opioids, or placebo for sedation and analgesia in neonates (aged under four weeks) requiring mechanical ventilation. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were level of sedation and level of analgesia. Our secondary outcomes included days on mechanical ventilation, number of infants requiring additional medication for sedation or analgesia (or both), hypotension, neonatal mortality, and neurodevelopmental outcomes. We planned to use GRADE to assess the certainty of evidence for each outcome. MAIN RESULTS: We identified no eligible studies for inclusion. We identified four ongoing studies, two of which appear to be eligible for inclusion; they will compare dexmedetomidine with fentanyl in newborn infants requiring surgery. We listed the other two studies as awaiting classification pending assessment of full reports. One study will compare dexmedetomidine with morphine in asphyxiated newborns undergoing hypothermia, and the other (mixed population, age up to three years) will evaluate dexmedetomidine versus ketamine plus dexmedetomidine for echocardiography. The planned sample size of the four studies ranges from 40 to 200 neonates. Data from these studies may provide some evidence for dexmedetomidine efficacy and safety. AUTHORS' CONCLUSIONS: Despite the increasing use of dexmedetomidine, there is insufficient evidence supporting its routine use for analgesia and sedation in newborn infants on mechanical ventilation. Furthermore, data on dexmedetomidine safety are scarce, and there are no data available on its long-term effects. Future studies should address the efficacy, safety, and long-term effects of dexmedetomidine as a single drug therapy for sedation and analgesia in newborn infants.

Exploring the impact of dexmedetomidine on short-term outcomes in critically ill sepsis-associated encephalopathy patients.

OBJECTIVE: Dexmedetomidine has demonstrated potential in preclinical medical research as a protective agent against inflammatory injuries and a provider of neuroprotective benefits. However, its effect on the short-term prognosis of patients with sepsis-associated encephalopathy remains unclear. This study aims to explore the underlying value of dexmedetomidine in these patients. PATIENTS AND METHODS: This study enrolled patients with sepsis-associated encephalopathy from the Medical Information Mart for Intensive Care (MIMIC)-IV database, and they were divided into two groups based on dexmedetomidine therapy during hospitalization. Propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) were utilized to balance the inter-group baseline differences. Kaplan-Meier (KM) curves with log-rank test and subgroup analysis were also employed. The primary outcome was 28-day mortality, and the secondary outcomes were in-hospital mortality, intensive care unit (ICU) stay time, hospital stay time, and the incidence of ventilator-associated pneumonia (VAP). RESULTS: After PSM, 1,075 pairs of patients were matched. In contrast to the non-dexmedetomidine cohort, the dexmedetomidine cohort did not exhibit a shortened ICU [4.65 (3.16, 8.55) vs. 6.14 (3.66, 11.04), p<0.001] and hospital stay duration [10.04 (6.55, 15.93) vs. 12.76 (7.92, 19.95), p<0.001], and there was an elevated incidence of VAP [90 (8.4%) vs. 135 (12.6%), p=0.002]. The log-rank test for the KM curves of dexmedetomidine use and 28-day mortality was statistically significant (p<0.001). The results showed that dexmedetomidine was associated with improved 28-day mortality [hazard ratio (HR) 0.46, 95% confidence interval (CI) 0.35-0.61, p<0.001] and in-hospital mortality (HR 0.50, 95% CI 0.37-0.67, p<0.001) after adjusting for various confounders. In the following subgroup analysis, dexmedetomidine infusion was associated with decreased 28-day mortality in most subgroups. CONCLUSIONS: Dexmedetomidine administration was significantly associated with reduced short-term mortality among patients with sepsis-associated encephalopathy in the ICU. However, it also prolonged ICU and hospital stays and increased the incidence of VAP.

Interventions to prevent and treat delirium: An umbrella review of randomized controlled trials.

Delirium is a common condition across different settings and populations. The interventions for preventing and managing this condition are still poorly known. The aim of this umbrella review is to synthesize and grade all preventative and therapeutic interventions for delirium. We searched five databases from database inception up to March 15th, 2023 and we included meta-analyses of randomized controlled trials (RCTs) to decrease the risk of/the severity of delirium. From 1959 records after deduplication, we included 59 systematic reviews with meta-analyses, providing 110 meta-analytic estimates across populations, interventions, outcomes, settings, and age groups (485 unique RCTs, 172,045 participants). In surgery setting, for preventing delirium, high GRADE evidence supported dexmedetomidine (RR=0.53; 95%CI: 0.46-0.67, k=13, N=3988) and comprehensive geriatric assessment (OR=0.46; 95%CI=0.32-0.67, k=3, N=496) in older adults, dexmedetomidine in adults (RR=0.33, 95%CI=0.24-0.45, k=7, N=1974), A2-adrenergic agonists after induction of anesthesia (OR= 0.28, 95%CI= 0.19-0.40, k=10, N=669) in children. High certainty evidence did not support melatonergic agents in older adults for delirium prevention. Moderate certainty supported the effect of dexmedetomidine in adults and children (k=4), various non-pharmacological interventions in adults and older people (k=4), second-generation antipsychotics in adults and mixed age groups (k=3), EEG-guided anesthesia in adults (k=2), mixed pharmacological interventions (k=1), five other specific pharmacological interventions in children (k=1 each). In conclusion, our work indicates that effective treatments to prevent delirium differ across populations, settings, and age groups. Results inform future guidelines to prevent or treat delirium, accounting for safety and costs of interventions. More research is needed in non-surgical settings.

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.

Analgesic Mechanism of Dexmedetomidine and Esketamine in Rats with Spinal Cord Injury.

BACKGROUND: Spinal cord injury (SCI) is usually caused by external direct or indirect factors, and with a high morbidity and mortality rate. The aim of this study was to observe the effects of Dexmedetomidine (DEX) combined with Esketamine (ESK) on pain behavior and potential analgesic mechanisms in rats with SCI. The goal was to provide a reliable multimodal analgesic medication regimen for SCI. METHODS: Thirty rats were divided into five groups with six rats in each group: Sham group, SCI group, DEX group, ESK group, and DEX+ESK group. The SCI model in rats was constructed, and the motor function of hind limbs of rats was measured using Basso Beattie Bresnahan (BBB) locomotor rating scale and inclined plate test. The levels of interleukin 18 (IL-18), interleukin 1ß (IL-1ß), and tumor necrosis factor-α (TNF-α) in the spinal cord were determined by enzyme-linked immunosorbent assay (ELISA). The expressions of substance P (SP), neurokinin-1 receptor (NK-1R), B cell lymphoma-2 (Bcl-2), and Bcl2-associated X protein (Bax) in the rats' spinal cord were measured by Western blot assay. The viability of spinal astrocytes was evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. RESULTS: After 7 days, the BBB scores were significantly higher in the DEX, ESK, and DEX+ESK groups compared to the SCI group (p < 0.01). Additionally, the DEX+ESK group had significantly higher scores than both the DEX and ESK groups (p < 0.01). The maximum angle of the DEX (p < 0.05), ESK (p < 0.05), and DEX+ESK groups (p < 0.01) were higher than the SCI group, and the maximum angle of DEX+ESK group was higher than DEX and ESK groups (p < 0.05). The levels of IL-18, IL-1ß, and TNF-α in the DEX, ESK, and DEX+ESK groups were lower than the SCI group (p < 0.01), while the DEX+ESK group had significantly lower IL-18, IL-1ß, and TNF-α levels than the DEX and ESK groups (p < 0.01). The levels of SP (p < 0.01) and NK-1R (p < 0.05) were lower in the DEX, ESK, and DEX+ESK groups compared to the SCI group, and the levels of SP and NK-1R were lower in the DEX+ESK group compared to the DEX and ESK groups (p < 0.01). The DEX and ESK groups suppressed the activity of spinal astrocytes (p < 0.01), however, the DEX+ESK group had larger effects on spinal astrocytes than the ESK group (p < 0.05). CONCLUSIONS: Treatment using DEX combined with ESK improves the motor function, inhibits inflammation and astrocyte activity, and exerts analgesic effects on rats with SCI. These findings can serve as a reference for the selection of multi-modal analgesics.

Comparative study between remifentanil (or fentanyl) and dexmedetomidine for the analgesia of rhinoplasty: A meta-analysis of randomized controlled trials.

BACKGROUND: Remifentanil (or fentanyl) and dexmedetomidine may have some potential to improve the analgesia of rhinoplasty, and this meta-analysis aims to compare their efficacy for the analgesia of rhinoplasty. METHODS: PubMed, Embase, Web of Science, EBSCO, and Cochrane Library databases were systematically searched, and we included randomized controlled trials (RCTs) assessing the analgesic effect of remifentanil (or fentanyl) versus dexmedetomidine for rhinoplasty. RESULTS: Four RCTs were finally included in the meta-analysis. In patients undergoing rhinoplasty, remifentanil (or fentanyl) infusion and dexmedetomidine infusion resulted in similar good patient satisfaction (odd ratio [OR] = 2.71; 95% confidence interval [CI] = 0.63 to 11.64; P = .18), good surgeon satisfaction (OR = 1.68; 95% CI = 0.02 to 181.40; P = .83), extubation time (mean difference [MD] = 7.56; 95% CI = -11.00 to 26.12; P = .42), recovery time (MD = -2.25; 95% CI = -23.41 to 18.91; P = .83), additional analgesic requirement (OR = 0.16; 95% CI = 0 to 8.65; P = .37) and adverse events (OR = 8.50; 95% CI = 0.47 to 153.30; P = .15). CONCLUSIONS: Remifentanil (or fentanyl) and dexmedetomidine may have comparable analgesia for patients undergoing rhinoplasty.

The effect of dexmedetomidine on the postoperative recovery of patients with severe traumatic brain injury undergoing craniotomy treatment: a retrospective study.

BACKGROUND: Traumatic brain injury (TBI) has been a worldwide problem for neurosurgeons. Patients with severe TBI may undergo craniotomy. These patients often require sedation after craniotomy. Dexmedetomidine (DEX) has been used in patients receiving anesthesia and in intensive care units. Not much is known about the postoperative effect of DEX in patients with severe TBIs undergoing craniotomy. The purpose of this study was to explore the effects of postoperative DEX administration on severe TBI patients who underwent craniotomy. METHODS: Patients who underwent craniectomy for severe TBI at our hospital between January 2019 and February 2022 were included in this study. The patients were admitted to the intensive care unit (ICU) after surgery to receive sedative medication. The patients were then divided into DEX and control groups. We analyzed the sedation, hemodynamics, and other conditions of the patients (hypoxemia, duration of ventilation during endotracheal intubation, whether tracheotomy was performed, and the duration in the ICU) during their ICU stay. Other conditions, such as delirium after the patients were transferred to the general ward, were also analyzed. RESULTS: A total of 122 patients were included in this study. Among them, 53 patients received DEX, and the remaining 69 did not. The incidence of delirium in the general ward in the DEX group was significantly lower than that in the control group (P < 0.05). The incidence of bradycardia in the control group was significantly lower than that in the DEX group (P < 0.05). Other data from the DEX group and the control group (hypotension, hypoxemia, etc.) were not significantly different (P > 0.05). CONCLUSION: The use of DEX in the ICU can effectively reduce the incidence of delirium in patients who return to the general ward after craniotomy. DEX had no adverse effect on the prognosis of patients other than causing bradycardia.

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.

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.

Effectiveness of Dexmedetomidine as Myocardial Protector in Children With Classic Tetralogy of Fallot Having Corrective Surgery: A Randomized Controlled Trial.

OBJECTIVES: Efficacy of dexmedetomidine (DEX) as a cardioprotective agent in Indonesian children undergoing classic tetralogy of Fallot (TOF) repair with cardiopulmonary bypass (CPB). DESIGN: A prospective, parallel trial using block randomization along with double-blinded preparation of treatment agents by other parties. SETTING: National Cardiovascular Center Harapan Kita, Indonesia. PARTICIPANTS: Sixty-six children with classic TOF scheduled for corrective surgery. No children were excluded. All patients had fulfilled the criteria for analysis. INTERVENTIONS: A total of 0.5 µg/kg bolus of DEX was added to the CPB priming solution, followed by 0.25 µg/kg/h maintenance during bypass. The placebo group used normal saline. Follow-ups were up to 30 days. MEASUREMENTS AND MAIN RESULTS: Troponin I was lower in the DEX group at 6 hours (30.48 ± 19.33 v 42.73 ± 27.16, p = 0.039) and 24 hours after CPB (8.89 ± 5.42 v 14.04 ± 11.17, p = 0.02). Within a similar timeframe, DEX successfully lowered interleukin-6 (p = 0.03; p = 0.035, respectively). Lactate was lower in the Dex group at 1, 6, and 24 hours after CPB (p < 0.01; p = 0.048; p = 0.035; respectively). Dexmedetomidine increased cardiac output and index from 6 hours after bypass, but vice versa in systemic vascular resistance. Reduction of vasoactive inotropic score was seen during intensive care unit monitoring in the Dex group (p = 0.049). Nevertheless, DEX did not significantly affect the length of ventilation (p = 0.313), intensive care unit stay (p = 0.087), and mortality (p > 0.99). CONCLUSIONS: Dexmedetomidine during CPB is an effective cardioprotective agent in TOF children having surgery. Postoperative mortality was comparable across groups.

Dexmedetomidine and Perioperative Arrhythmias.

The highly selective α2-adrenoceptor agonist dexmedetomidine is a commonly used sedative drug for patients undergoing anesthesia and intensive care treatment. Several studies have indicated that dexmedetomidine may have a potential role in preventing and treating perioperative tachyarrhythmias. However, the specific effect and mechanism of action of dexmedetomidine in this context remain unclear. Dexmedetomidine is known to regulate the electrophysiologic function of the myocardium by inhibiting the function of the sinus node and atrioventricular node, as well as affecting myocardial repolarization. This paper aims to provide a theoretical basis for the prevention and treatment of perioperative arrhythmias by summarizing the effects of dexmedetomidine on myocardial electrophysiologic function and its impact on different types of arrhythmias.

The effect of dexmedetomidine, remifentanil and metoral in reducing patient bleeding during rhinoplasty surgery.

INTRODUCTION: Rhinoplasty is one of the most common surgeries in the ENT department. Rhinoplasty hemorrhage is one of the complications that different strategies have been used to reduce it. Reduction of bleeding reduces the risk of complications such as hemolytic and non-hemolytic reactions, acute lung damage, viral and bacterial infections, hypothermia and coagulation disorders. Therefore, the aim of this study was to compare the effect of dexmedetomidine, remifentanil and metoral in reducing patient bleeding during rhinoplasty surgery. MATERIALS AND METHODS: This randomized, double-blind trial was performed on rhinoplasty patients. Rhinoplasty candidates who had the inclusion and exclusion criteria were divided into three groups of remifentanil, metoral and dexmedetomidine according to the random number table. Then 0.5 mg/kg/h of dexmedetomidine in the first group was administered, followed by 100-150 kg/h remifentanil in the second group and 50 mg metoral in the third group. Mean blood pressure, heart rate, mean bleeding and surgeon satisfaction were recorded in designed form. Data were analyzed by Spss-22 software. RESULTS: The mean blood pressure of patients in remifentanil group was lower than the other two groups (P = 0.03). In all three times during surgery, recovery and overall time, the amount of bleeding in the remifentanil group was found to be less than the other two groups. Furthermore, the rate of bleeding in the dexmedetomidine group was found to be less than the metoral group (P = 0.03, P = 0.02). The surgeon's satisfaction score in the remifentanil group was higher than the other two groups. Satisfaction score was higher in dexmedetomidine group than metoral group (P = 0.03). The recovery time in the metoral group was shorter than the other two groups (P = 0.02). CONCLUSION: Remifentanil caused a good and appropriate reduction of blood pressure in rhinoplasty surgery, causing less bleeding and higher satisfaction.