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.

Use of orally administered dexmedetomidine to induce emesis in cats.

CASE SERIES SUMMARY: This case series describes the use of orally administered dexmedetomidine at a dose of 20 µg/kg to induce emesis in six cats. Emesis was successfully induced in 5/6 cats, with each of the cats vomiting once. The reasons for inducing vomiting included known or suspected ingestion of lilies, onions, acetaminophen (paracetamol) or acetylsalicylic acid. Four of the five cats in which emesis induction was successful did not develop any clinical signs of toxicity associated with the toxin ingested; the fifth cat developed clinicopathological changes consistent with acetaminophen toxicity. All six cats exhibited moderate to profound sedation, as expected, but no other adverse effects were documented. RELEVANCE AND NOVEL INFORMATION: Induction of emesis in cats is notoriously difficult. This case series describes a novel route of administration of dexmedetomidine, a commonly available medication, with a high success rate observed for inducing emesis in this group of cats.

Cats are notoriously more difficult to elicit vomiting in than dogs. This case series describes the use of a novel way of giving cats a commonly available veterinary medication to cause vomiting. The medication, dexmedetomidine, was given by mouth to six cats, of which five vomited. All six cats had eaten toxins: lilies, acetaminophen (paracetamol), aspirin or onions. Four of the five cats that vomited did not develop any signs of toxicity. All six cats that received the medication became sedated, but no other side effects were noted.

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.

Comparison of sedation with dexmedetomidine administered subcutaneously at 2 different locations on the head in dogs.

Objective: This study aimed to compare the sedative effects of dexmedetomidine administered to dogs subcutaneously (SC) at the Governing Vessel 20 (GV20) acupuncture point and at another point on the head. Animals and procedure: Ten client-owned dogs were included. Dogs were sedated 2 times, 14 d apart, with 200 µg/m2 of dexmedetomidine, SC, at GV20 and at a point at the base of the ear (SC-head). The sedation was assessed with a sedation scale and a Dynamic and Interactive Visual Analogue Scale (DIVAS). The ease of performing radiographic studies, physiological parameters, and adverse events were recorded. Statistical linear mixed-effect models (ANOVA) were applied. Statistical significance was set at P < 0.05. Results: The time to sedation and sedation scores were similar for both groups. The level of sedation achieved was adequate to perform orthopedic radiographs for 9/10 (90%) cases in the GV20 group and 8/10 (80%) cases in the SC-head group. Heart and respiratory rates decreased significantly over time in both groups (P < 0.001). Adverse events were infrequent and self-limiting. Conclusion: Our study provides evidence that SC administration of dexmedetomidine on the head, at the GV20 point or at the base of the ear, is easy and provides a sufficient level of sedation to obtain orthopedic radiographs in dogs.

Comparaison de la sédation avec de la dexmédétomidine administrée par voie sous-cutanée à deux sites différents sur la tête de chiens. Objectif: Cette étude a pour but de comparer les effets sédatifs de la dexmédétomidine administrée par voie sous-cutanée (SC) au point d'acupuncture VG20 et à un autre point sur la tête, non lié à la relaxation/sédation, chez le chien. Animaux et procédure: Dix chiens de clients ont été inclus dans cette étude clinique, prospective, croisée, randomisée et à l'aveugle. Les chiens ont été sédatés deux fois, à 14 jours d'intervalle, avec une injection de 200 µg/m2 de dexmédétomidine sous-cutanée au point d'acupuncture VG20 et à un autre point sur la tête, à la base de l'oreille (SC-tête). La durée et la qualité de la sédation ont été évaluées avec une échelle de sédation et une échelle analogue visuelle dynamique et interactive (DIVAS). La facilité de réaliser des études radiographiques, les paramètres physiologiques et les effets secondaires ont été enregistrés. Des modèles statistiques linéaires à effet mixte (ANOVA) ont été réalisés. Les résultats étaient considérés comme significatifs quand P < 0,05. Résultats: Le temps nécessaire pour atteindre un niveau de sédation adéquat et les scores de sédation étaient comparables entre les deux groupes. Le niveau de sédation était adéquat pour réaliser des radiographies orthopédiques chez 9/10 (90 %) des cas dans le groupe VG20 et 8/10 (80 %) des cas dans le groupe SC-tête. Les fréquences cardiaque et respiratoire diminuaient significativement dans le temps pour les 2 groupes (P < 0,001). Les effets indésirables étaient peu fréquents et auto-limitants. Conclusion: Notre étude suggère que l'administration sous-cutanée de dexmédétomidine sur la tête, que ce soit au point VG20 ou à la base de l'oreille, est facile et permet d'obtenir un niveau de sédation suffisant pour réaliser des radiographies orthopédiques chez des chiens sains.(Traduit par les auteurs).

The Safety and Efficacy of Remimazolam Compared to Dexmedetomidine for Awake Tracheal Intubation by Flexible Bronchoscopy: A Randomized, Double-Blind, Controlled Trial.

Background: Remimazolam is a novel ultra-short-acting benzodiazepine sedative that has the potential to be an alternative for procedural sedation due to its rapid sedation and recovery, no accumulation effect, stable hemodynamics, minimal respiratory depression, anterograde amnesia effect, and specific antagonist. Here, we aimed to compare the safety and efficacy of remimazolam with dexmedetomidine for awake tracheal intubation by flexible bronchoscopy (ATI-FB). Methods: Ninety patients scheduled for ATI-FB were randomly divided into three groups, each consisting of 30 cases: dexmedetomidine 0.6 µg/kg + sufentanil (group DS), remimazolam 0.073 mg/kg + sufentanil (group R1S), or remimazolam 0.093 mg/kg + sufentanil (group R2S). The primary outcome was the success rate of sedation. Secondary outcomes were MOAA/S scores, hemodynamic and respiratory parameters, intubation conditions, intubation time, tracheal intubation amnesia, and adverse events. Results: The success rates of sedation in groups R2S and DS were higher than that in group R1S (93.3%, 86.7%, respectively, vs 58.6%; P = 0.002), and intubation conditions were better than those in group R1S (P < 0.05). Group R2S had shorter intubation times than groups R1S and DS (P = 0.003), and a higher incidence of tracheal intubation amnesia than group DS (P = 0.006). No patient in the three groups developed hypoxemia or hypotension, and there were no significant differences in oligopnea, PetCO2, or bradycardia (P > 0.05). Conclusion: In conclusion, both DS and R2S had higher success rates of sedation, better intubation conditions, and minor respiratory depression, but R2S, with its shorter intubation time, higher incidence of anterograde amnesia, and ability to be antagonized by specific antagonists, may be a good alternative sedation regimen for patients undergoing ATI-FB.

Mechanism of dexmedetomidine protection against cisplatin induced acute kidney injury in rats.

OBJECTIVE: This study explored the molecular mechanisms by which dexmedetomidine (Dex) alleviates cisplatin (CP)-induced acute kidney injury (AKI) in rats. METHODS: CP-induced AKI models were established, and Dex was intraperitoneally injected at different concentrations into rats in the model groups. Subsequently, rats were assigned to the control, CP, CP + Dex 10 µg/kg, and CP + Dex 25 µg/kg groups. After weighing the kidneys of the rats, the kidney arterial resistive index was calculated, and CP-induced AKI was evaluated. In addition, four serum biochemical indices were measured: histopathological damage in rat kidneys was detected; levels of inflammatory factors, interleukin (IL)-1ß, IL-18, IL-6, and tumor necrosis factor alpha, in kidney tissue homogenate of rats were assessed through enzyme-linked immunosorbent assay (ELISA); and levels of NLRP-3, caspase-1, cleaved caspase-1, gasdermin D (GSDMD), and GSDMD-N in kidney tissues of rats were determined via western blotting. RESULTS: Dex treatment reduced nephromegaly and serum clinical marker upregulation caused by CP-induced AKI. In addition, hematoxylin and eosin staining revealed that Dex treatment relieved CP-induced kidney tissue injury in AKI rats. ELISA analyses demonstrated that Dex treatment reduced the upregulated levels of proinflammatory cytokines in the kidney tissue of AKI rats induced by CP, thereby alleviating kidney tissue injury. Western blotting indicated that Dex alleviated CP-induced AKI by inhibiting pyroptosis mediated by NLRP-3 and caspase-1. CONCLUSION: Dex protected rats from CP-induced AKI, and the mechanism may be related to NLRP-3/Caspase-1-mediated pyroptosis.

Comparative evaluation of nebulized versus intravenous dexmedetomidine on intubating conditions during awake fiberoptic nasotracheal intubation.

BACKGROUND: There is a search for an ideal agent to facilitate awake fiberoptic intubation (AFOI). Dexmedetomidine is a selective α2 agonist which can be administered through intravenous, intramuscular, buccal, intranasal & inhalational routes. It provides good intubation conditions without oxygen desaturation but may cause hypotension and bradycardia when administered intravenously. Hence, alternative routes of administering dexmedetomidine which may improve its safety profile are worth exploring. METHODS: In this randomised, controlled, double-blind trial, 46 ASA I/II adult participants scheduled for elective ENT surgery were randomly allocated to Group ND (Nebulised Dexmedetomidine) (n = 23) to receive nebulisation with dexmedetomidine 1µg.kg-1 and Group ID (Intravenous Dexmedetomidine) (n = 23) to receive intravenous dexmedetomidine 1µg.kg-1 before AFOI. All the patients received injection midazolam 1 mg i.v. as premedication before anaesthesia was initiated. The primary outcome was the cough score. The secondary outcomes were the RSS, SAYGO boluses, post-intubation score, hemodynamic parameters, recall of the procedure, patient satisfaction score and any side effects. RESULTS: The cough score was significantly lower in nebulized group (2.43 ± 0.992 vs 3.52 ± 1.082) with p = 0.001. RSS(3.30 ± 0.926 vs 4.22 ± 1.126; p = 0.004), number of SAYGO boluses required (2.74 ± 0.864 vs 3.57 ± 1.161; p = 0.009) & the post intubation score (1.48 ± 0.593 vs 2.17 ± 0.778; p = 0.001) were also significantly lower in nebulized group. CONCLUSIONS: Nebulisation with dexmedetomidine results in desirable degree of sedation and better tolerance of the procedure with adequate attenuation of the haemodynamic responses to intubation.

Dexmedetomidine Pretreatment Confers Myocardial Protection and Reduces Mechanical Ventilation Duration for Patients Undergoing Cardiac Valve Replacement under Cardiopulmonary Bypass.

PURPOSE: The study aims to assess the effects of dexmedetomidine (Dex) pretreatment on patients during cardiac valve replacement under cardiopulmonary bypass. METHODS: For patients in the Dex group (n = 52), 0.5 µg/kg Dex was given before anesthesia induction, followed by 0.5 µg/kg/h pumping injection before aortic occlusion. For patients in the control group (n = 52), 0.125 ml/kg normal saline was given instead of Dex. RESULTS: The patients in the Dex group had longer time to first dose of rescue propofol than the control group (P = 0.003). The Dex group required less total dosage of propofol than the control group (P = 0.0001). The levels of cardiac troponin I (cTnI), creatine kinase isoenzyme MB (CK-MB), malondialdehyde (MDA), and tumor necrosis factor-α (TNF-α) were lower in the Dex group than the control group at T4, 8 h after the operation (T5), and 24 h after the operation (T6) (P <0.01). The Dex group required less time for mechanical ventilation than the control group (P = 0.003). CONCLUSION: The study suggests that 0.50 µg/kg Dex pretreatment could reduce propofol use and the duration of mechanical ventilation, and confer myocardial protection without increased adverse events during cardiac valve replacement.

Effect of Postoperative Prolonged sedation with Dexmedetomidine after successful reperfusion with Endovascular Thrombectomy on long-term prognosis in patients with acute ischemic stroke (PPDET): study protocol for a randomized controlled trial.

BACKGROUND: Endovascular thrombectomy (EVT) is a standard treatment for acute ischemic stroke (AIS) with large vessel occlusion. Hypertension and increased blood pressure variability within the first 24 h after successful reperfusion are related to a higher risk of symptomatic intracerebral hemorrhage and higher mortality. AIS patients might suffer from ischemia-reperfusion injury following reperfusion, especially within 24 h. Dexmedetomidine (DEX), a sedative commonly used in EVT, can stabilize hemodynamics by inhibiting the sympathetic nervous system and alleviate ischemia-reperfusion injury through anti-inflammatory and antioxidative properties. Postoperative prolonged sedation for 24 h with DEX might be a potential pharmacological approach to improve long-term prognosis after EVT. METHODS: This single-center, open-label, prospective, randomized controlled trial will include 368 patients. The ethics committee has approved the protocol. After successful reperfusion (modified thrombolysis in cerebral infarction scores 2b-3, indicating reperfusion of at least 50% of the affected vascular territory), participants are randomly assigned to the intervention or control group. In the intervention group, participants will receive 0.1~1.0 µg/kg/h DEX for 24 h. In the control group, participants will receive an equal dose of saline for 24 h. The primary outcome is the functional outcome at 90 days, measured with the categorical scale of the modified Rankin Scale, ranging from 0 (no symptoms) to 6 (death). The secondary outcome includes (1) the changes in stroke severity between admission and 24 h and 7 days after EVT, measured by the National Institute of Health Stroke Scale (ranging from 0 to 42, with higher scores indicating greater severity); (2) the changes in ischemic penumbra volume/infarct volume between admission and 7 days after EVT, measured by neuroimaging scan; (3) the length of ICU/hospital stay; and (4) adverse events and the all-cause mortality rate at 90 days. DISCUSSION: This randomized clinical trial is expected to verify the hypothesis that postoperative prolonged sedation with DEX after successful reperfusion may promote the long-term prognosis of patients with AIS and may reduce the related socio-economic burden. TRIAL REGISTRATION: ClinicalTrials.gov NCT04916197. Prospectively registered on 7 June 2021.

[Pediatric procedural sedation: a new protocol implemented]. / Implémentation d'un nouveau protocole pour la sédation procédurale pédiatrique.

Pediatric procedural sedation is a difficult exercise aiming to find the balance between optimal quality of a medical imaging or act, and maximal reduction of risks for the patient. Harmlessness of chloral hydrate has been recently questioned, thus promoting the use of the dexmedetomidine for these kinds of procedures. In this context we decided to develop a new protocol at the CHUV. We tested different combinations of molecules until we found the best association and dosage. We present here the analysis of our patient cohort, attesting the efficiency, reliability, and safety of combined dexmedetomidine and midazolam given intranasal for pediatric MRI.

La sédation procédurale pédiatrique représente un défi pour garantir la qualité optimale d'un examen ou d'un acte médical tout en assurant la sécurité maximale du patient. Comme l'innocuité de l'hydrate de chloral semble être remise en question, la communauté médicale se dirige de plus en plus vers l'usage intranasal de la dexmédétomidine pour les sédations. Dans ce contexte, nous avons élaboré un nouveau protocole au CHUV, après avoir testé différentes combinaisons médicamenteuses dans le cadre d'examen d'imagerie (IRM). Sur la base de nos résultats, il semble que l'efficacité, la fiabilité et la sécurité de la combinaison de dexmédétomidine et de midazolam par voie intranasale soient très satisfaisantes.

Effect of Dexmedetomidine on Intraoperative Hemodynamics and Blood Loss in Patients Undergoing Spine Surgery: A Systematic Review and Meta-Analysis.

Objective Dexmedetomidine (Dex) is a highly selective α2 adrenoceptor agonist that reduces blood pressure and heart rate. However, its ability to provide stable hemodynamics and a clinically significant reduction in blood loss in spine surgery is still a matter of debate. This study aimed to investigate the effects of Dex on intraoperative hemodynamics and blood loss in patients undergoing spine surgery.Methods The Web of Science, MEDLINE, EMBASE, and the Cochrane Library were searched up to February 2023 for randomized controlled trials (RCTs) including patients undergoing spine surgeries under general anaesthesia and comparing Dex and saline. A fixed- or random-effect model was used depending on heterogeneity.Results Twenty-one RCTs, including 1388 patients, were identified. Dex added the overall risk of intraoperative hypotension (odds ratio [OR]: 2.11; 95% confidence interval [CI]: 1.24 - 3.58; P=0.006) and bradycardia (OR: 2.48; 95%CI: 1.57 - 3.93; P=0.0001). The use of a loading dose of Dex led to significantly increased risks of intraoperative hypotension (OR: 2.00; 95%CI: 1.06 - 3.79; P=0.03) and bradycardia (OR: 2.28; 95%CI: 1.42 - 3.66; P=0.0007). For patients receiving total intravenous anesthesia, there was an increased risk of hypotension (OR: 2.90; 95%CI: 1.24 - 6.82; P=0.01) and bradycardia (OR: 2.66; 95%CI: 1.53 - 4.61; P=0. 0005). For patients in the inhalation anesthesia group, only an increased risk of bradycardia (OR: 4.95; 95%CI: 1.41 - 17.37; P=0.01) was observed. No significant increase in the risk of hypotension and bradycardia was found in the combined intravenous-inhalation anesthesia group. The incidence of severe hypotension (OR: 2.57; 95%CI: 1.05 - 6.32; P=0.04), but not mild hypotension, was increased. Both mild (OR: 2.55; 95%CI: 1.06 - 6.15; P=0.04) and severe (OR: 2.45; 95%CI: 1.43 - 4.20; P=0.001) bradycardia were associated with a higher risk. The overall analyses did not reveal significant reduction in intraoperative blood loss. However, a significant decrease in blood loss was observed in total inhalation anesthesia subgroup (mean difference [MD]: -82.97; 95%CI: -109.04 - -56.90; P<0.001).Conclusions Dex increases the risks of intraoperative hypotension and bradycardia in major spine surgery. The administration of a loading dose of Dex and the utilization of various anesthesia maintenance methods may potentially impact hemodynamic stability and intraoperative blood loss.

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.

Safety and effcacy of remimazolam tosilate for sedation during combined spinal-epidural anesthesia for orthopedic procedures: a randomized controlled trial.

OBJECTIVE: The objective of this study was to assess the efficacy and safety of Remimazolam in the context of combined spinal-epidural anesthesia for sedation during orthopedic surgery. METHODS: This randomized controlled trial enrolled patients scheduled for orthopedic surgery under combined spinal-epidural anesthesia (N = 80), who were randomly allocated to receive either dexmedetomidine (Group-D) or remimazolam (Group-R). The target sedation range aimed for a Ramsay score of 2-5 or a BIS value of 60-80 to evaluate the effectiveness and safety of remimazolam during sedation. RESULTS: The time taken to achieve the desired level of sedation was significantly shorter in the remimazolam group compared to the dexmedetomidine group (3.69 ± 0.75 vs. 9.59 ± 1.03; P < 0.0001). Patients in the remimazolam group exhibited quicker recovery, fewer intraoperative adverse events, more consistent vital signs, and greater satisfaction at various time points throughout the surgery. CONCLUSION: This preliminary study demonstrates that remimazolam tosilate serves as a safe and effective sedative for orthopedic surgery performed under combined spinal-epidural anesthesia, in comparison with dexmedetomidine.

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.].

Effects of dexmedetomidine combined with etomidate on postoperative cognitive function in older patients undergoing total intravenous anaesthesia: a randomized, double-blind, controlled trial.

BACKGROUND: Etomidate has been advocated for anesthesia in older and critically ill patients because of its hemodynamic stability. Clinical studies have shown that dexmedetomidine has neuroprotective and anti-inflammatory properties and improves postoperative cognitive dysfunction in older patients. The present study was to evaluate the effects of the combination of etomidate and dexmedetomidine with different anaesthesia time on postoperative cognitive function in older patients. METHODS: A total of 132 older patients undergoing ureteroscopic holmium laser lithotripsy were randomly divided into EN group and ED group equally. Patients whose surgery time was less than or equal to 1 h in each group were allocated to short-time surgery group (EN1 group and ED1 group), and whose surgery time was more than 1h were allocated to long-term surgery group (EN2 group and ED2 group). The primary outcome was the score of the Mini-Mental State Examination. The secondary outcomes were State-Trait Anxiety Inventory scores, Riker sedation agitation scores, Zung Self-Rating Depression Scale scores, the memory span for Arabic numerals, the plasma concentrations of S-100 calcium-binding protein B and neuron specific enolase, the time to spontaneous respiration, recovery, and extubation. RESULTS: The MMSE scores at t2-3 were higher in ED1 and ED2 groups than in EN1 and EN2 groups (p<0.05). Compared with ED1 and ED2 groups, the ZSDS scores, the S-AI scores and the T-AI scores at t1-2 were higher in EN1 and EN2 groups (p<0.05), respectively. The recalled Arabic numbers at t1-3 were higher in ED2 group than in EN2 group (p<0.05). The plasma concentration of S-100ß at t1-2 in EN1 group and t1-3 in EN2 group were higher than that in ED1 and ED2 groups (p<0.05), respectively. Compared with ED1 and ED2 groups, the plasma concentrations of NSE were higher at t1-3 in EN1 group and t1-4 in EN2 group (p<0.05), respectively. CONCLUSION: The administration of dexmedetomidine could improve postoperative cognitive dysfunction, emergence agitation, depression and anxiety, attenuate the plasma concentrations of S-100ß and NSE in older patients undergoing total intravenous anaesthesia with etomidate. TRIAL REGISTRATION: Registration number: ChiCTR1800015421, Date: 29/03/2018.

Comparison of the effect of dexmedetomidine intrathecal injection and intravenous infusion on subarachnoid blockade during knee arthroscopy procedures: a randomized controlled trial.

BACKGROUND: Comparison of whether intrathecal dexmedetomidine prolongs spinal anesthesia-associated sensorimotor blockade more than intravenous infusion during knee arthroscopy procedures performed under subarachnoid blockade. METHODS: Ninety patients aged 18-75 years, ASA class I-II, who underwent knee arthroscopy between October 2022 and April 2023 were randomized into intrathecal、intravenous and control groups.Subjects received three modes of administration: an intrathecal group (2 ml of 1% ropivacaine + 1 ml of 5 µg dexmedetomidine, along with intravenous saline infusion), an intravenous group (intrathecal 2 ml of 1% ropivacaine + 1 ml of 0.9% saline, with dexmedetomidine pumped intravenously at a dose of 0.5 µg/kg/h), and a control group (intrathecal 2 ml of 1% ropivacaine + 1 ml of 0.9% saline, along with intravenous saline infusion). Total analgesic duration, duration of sensory and motor blockade, Ramsay sedation score, Visual Analogue Score (VAS) at different postoperative time points, and occurrence of adverse effects were recorded. RESULTS: The total analgesia duration was significantly longer in the intrathecal group than in the intravenous and control groups (352.13 ± 51.70 min VS 273.47 ± 62.57 min VS 241.41 ± 59.22 min, P < 0.001).The onset of sensory block was shorter in the intrathecal group than in the intravenous and control groups (4 [3-4]min VS 5 [4-5]min VS 5 [4-5]min; P < 0.001);the onset of motor block was shorter in the intrathecal group than in the intravenous group and the control group (5 [4-5]min VS 5 [5-6]min VS 6[5.5-7]min; P < 0.001).Sedation scores were higher in the intravenous group than in the intrathecal and control groups (P < 0.001). At 5 h postoperatively, the VAS score in the intrathecal group was lower than that in the intravenous and control groups (P < 0.001). At 24 h postoperatively, the VAS score in the intrathecal group was lower than that in the control group (P < 0.001). In addition, the incidence of bradycardia was significantly higher in the intravenous group than in the intrathecal and control groups (30%, 6.5%, and 3.4%, respectively; P = 0.018, P = 0.007). CONCLUSIONS: Intrathecal administration of dexmedetomidine did prolong the total analgesia duration, as well as accelerate the onset of sensory-motor blockade compared with intravenous infusion, and did not result in any hemodynamic instability or other adverse events at the doses studied. TRIAL REGISTRATION: This single-center, prospective, RCT has completed the registration of the Chinese Clinical Trial Center at 26/09/2023 with the registration number ChiCTR2300076170.

Safety, Efficacy, and Clinical Outcomes of Dexmedetomidine for Sedation in Traumatic Brain Injury: A Scoping Review.

Dexmedetomidine is a promising alternative sedative agent for moderate-severe Traumatic brain injury (TBI) patients. Although the data are limited, the posited benefits of dexmedetomidine in this population are a reduction in secondary brain injury compared with current standard sedative regimens. In this scoping review, we critically appraised the literature to examine the effects of dexmedetomidine in patients with moderate-severe TBI to examine the safety, efficacy, and cerebral and systemic physiological outcomes within this population. We sought to identify gaps in the literature and generate directions for future research. Two researchers and a librarian queried PubMed, Embase, Scopus, and APA PsycINFO databases. Of 920 studies imported for screening, 11 were identified for inclusion in the review. The primary outcomes in the included studied were cerebral physiology, systemic hemodynamics, sedation levels and delirium, and the presence of paroxysmal sympathetic hyperactivity. Dexmedetomidine dosing ranged from 0.2 to 1 ug/kg/h, with 3 studies using initial boluses of 0.8 to 1.0 ug/kg over 10 minutes. Dexmedetomidine used independently or as an adjunct seems to exhibit a similar hemodynamic safety profile compared with standard sedation regimens, albeit with transient episodes of bradycardia and hypotension, decrease episodes of agitation and may serve to alleviate symptoms of sympathetic hyperactivity. This scoping review suggests that dexmedetomidine is a safe and efficacious sedation strategy in patients with TBI. Given its rapid onset of action and anxiolytic properties, dexmedetomidine may serve as a feasible sedative for TBI patients.

Comparison of dexmedetomidine and a dexmedetomidine-esketamine combination for reducing dental anxiety in preschool children undergoing dental treatment under general anesthesia: A randomized controlled trial.

BACKGROUND: Dental anxiety is a widespread complication occurring in pediatric patients during dental visits and may lead to undesirable complications. Esketamine may be effective in anxiety. OBJECTIVE: The objective of this study was to investigate the effect of premedication with a dexmedetomidine-esketamine combination compared with dexmedetomidine alone on dental anxiety in preschool children undergoing dental treatment under general anesthesia. METHODS: This is a prospective, double-blinded, randomized controlled trial. A total of 84 patients were scheduled for elective outpatient dental caries treatment under general anesthesia. Patients were randomly premedicated with intranasal dexmedetomidine (group D) or intranasal dexmedetomidine-esketamine (group DS). The primary outcome was the level of dental anxiety assessed by the Modified Child Dental Anxiety Scale (MCDAS) at 2 h after surgery. Secondary outcomes included level of dental anxiety at 1 day and 7 days after surgery, the incidence of dental anxiety at 2 h, 1 day, and 7 days after surgery, sedation onset time, overall success of sedation, acceptance of mask induction, postoperative pain intensity, incidence of emergence agitation in PACU, adverse reactions, HR, and SpO2 before premedication (baseline) and at 10, 20, and 30 min after the end of study drug delivery. RESULTS: The dental anxiety in group DS was lower than that in group D at 2 h, 1 day, and 7 days postoperatively (P = 0.04, 0.004, and 0.006, respectively). The incidences of dental anxiety in group DS were lower than those in group D at 2 h (53 % vs 76 %, P = 0.03), 1 day (47 % vs 71 %, P = 0.04), and 7 days (44 % vs 71 %, P = 0.02) after surgery. Group DS had a higher success rate of sedation (P = 0.03) but showed a lower MAS score (P = 0.005) and smoother hemodynamics (P < 0.01) after drug administration than group D. Group DS showed a significantly lower incidence rate of emergence agitation (P = 0.03) and postoperative pain intensity (P = 0.006) than that in group D during the anesthesia recovery time. The occurrence of adverse reactions was similar in both groups (P > 0.05). LIMITATIONS: We did not analyze and correct for the learning effect caused by repeated applications of the MCDAS and MCDAS scores on the 1 day after surgery were obtained by telephone follow-up. CONCLUSIONS: Compared to premedication with dexmedetomidine alone, premedication with intranasal dexmedetomidine combined with esketamine could significantly improve dental anxiety in preschool children undergoing dental treatment under general anesthesia.

Dexmedetomidine in the emergency department: A prospective observational cohort study.

BACKGROUND: Dexmedetomidine (DEX) is a centrally acting sympatholytic sedative. Abundant evidence from the intensive care unit and other settings demonstrates that the use of DEX is associated with improved sedation-related outcomes. There is a paucity of data on the use and efficacy of DEX in the emergency department (ED). METHODS: We performed a prospective single-center observational cohort study of patients treated with intravenous DEX for any indication in the ED. We performed serial bedside evaluations of sedation depth and delirium and administered standardized questionnaires to ED physicians about their use of DEX. We assessed the incidence of hemodynamic adverse events (HAEs; bradycardia or hypotension), clinically significant HAEs (HAEs accompanied by clinical intervention or discontinuation of DEX), sedation-related ED outcomes, and clinician perception of DEX effectiveness. RESULTS: We enrolled 75 patients treated with DEX in the ED during our study period. The most common indication for DEX was noninvasive positive pressure ventilation (32 patients, 43%). DEX was administered in the ED for a median of 2.6 h (interquartile range [IQR] 1.6-4.9 h), with a median infusion rate of 0.3 µg/kg/h (IQR 0.2-0.4 µg/kg/h). Clinically significant HAE occurred in nine patients (12%, 95% CI 6%-22%). Other sedative or analgesic infusions were administered in the ED to 21 patients (28%). Clinicians felt DEX was highly effective (median [IQR] effectiveness score of 5 [3-5] on a 5-point Likert scale). The median (IQR) ED Richmond Agitation Sedation Scale post-DEX was -1 (-4 to 0). CONCLUSIONS: DEX is used in the ED for diverse indications. Additional data from larger cohorts and comparative studies are required to determine the precise incidence of clinically significant HAE associated with DEX use in the ED. ED clinicians have a positive perception of the effectiveness of DEX.

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.