Effective remimazolam loading dose for adequate sedation in regional anesthesia.

PURPOSE: Remimazolam is a novel ultrashort-acting sedative considered appropriate for continuous infusion during surgical procedures. Nevertheless, information regarding its loading dose for sedation during surgery is limited. We aimed to determine the 90% effective dose (ED90) of the remimazolam loading dose for sedation in patients undergoing limb surgery under regional anesthesia. METHODS: We included 50 patients aged 19-80 yr undergoing limb surgery under regional anesthesia. After regional anesthesia, remimazolam besylate was administered at the assigned dose. For ten minutes after the initiation of loading, the level of sedation was evaluated using the Modified Observer's Assessment of Alertness/Sedation (MOAA/S) scale. The primary outcome was the ED90 based on whether patients reached a MOAA/S score of ≤ 3 points (loss of response to verbal command) within ten minutes. The secondary outcomes were the ED50 and the estimated effect site and plasma concentration at the time of achieving successful sedation. RESULTS: In total, 49 patients were included in the final analysis, and adequate sedation with the assigned loading dose was successful in 42 patients. The log-logistic function showed that the ED90 and ED50 were 0.617 mg·kg-1·hr-1 (95% confidence interval [CI], 0.511 to 0.722; 98% CI, 0.492 to 0.741) and 0.438 mg·kg-1·hr-1 (95% CI, 0.335 to 0.541; 98% CI, 0.315 to 0.560), respectively. CONCLUSION: The ED90 of the remimazolam loading dose to achieve adequate sedation in patients undergoing limb surgery under regional anesthesia was 0.617 mg·kg-1·hr-1 (95% CI, 0.511 to 0.722; 98% CI, 0.492 to 0.741). STUDY REGISTRATION: ClinicalTrials.gov (NCT05340335); first posted 22 April 2022.

RéSUMé: OBJECTIF: Le remimazolam est un nouveau sédatif à action ultracourte considéré comme approprié pour la perfusion continue pendant les interventions chirurgicales. Néanmoins, les informations concernant sa dose de charge pour la sédation pendant la chirurgie sont limitées. Notre objectif était de déterminer la dose efficace à 90 % (DE90) de la dose de charge de remimazolam pour la sédation chez la patientèle bénéficiant d'une chirurgie d'un membre sous anesthésie régionale. MéTHODE: Cinquante personnes âgées de 19 à 80 ans bénéficiant d'une chirurgie des membres sous anesthésie régionale ont été incluses. Après l'anesthésie régionale, du bésylate de remimazolam a été administré à la dose assignée. Pendant dix minutes après le début de la charge, le niveau de sédation a été évalué à l'aide de l'échelle modifiée d'évaluation de la vigilance/sédation par l'observateur (MOAA/S). Le critère d'évaluation principal était la DE90 selon que les patient·es ont atteint un score MOAA/S de ≤ 3 points (perte de réponse à la commande verbale) dans les dix minutes. Les critères d'évaluation secondaires étaient la DE50 et l'estimation du site d'effet et de la concentration plasmatique au moment de l'obtention d'une sédation réussie. RéSULTATS: Au total, 49 personnes ont été incluses dans l'analyse finale, et une sédation adéquate avec la dose de charge assignée a été couronnée de succès chez 42 d'entre elles. La fonction log-logistique a montré que les DE90 et DE50 étaient de 0,617 mg·kg−1·h−1 (intervalle de confiance [IC] à 95 %, 0,511 à 0,722; IC 98 %, 0,492 à 0,741) et 0,438 mg·kg−1·h−1 (IC 95 %, 0,335 à 0,541; IC 98 %, 0,315 à 0,560), respectivement. CONCLUSION: La DE90 de la dose de charge de remimazolam pour obtenir une sédation adéquate chez les personnes bénéficiant d'une chirurgie des membres sous anesthésie régionale était de 0,617 mg·kg−1·h−1 (IC 95 %, 0,511 à 0,722; IC 98 %, 0,492 à 0,741). ENREGISTREMENT DE L'éTUDE: ClinicalTrials.gov (NCT05340335); première publication le 22 avril 2022.

Effect of Remimazolam- versus Propofol-Based Total Intravenous General Anesthesia on Intraoperative Hemodynamic Stability for Major Spine Surgery in the Prone Position: A Randomized Controlled Trial.

Background and Objectives: Remimazolam offers advantages over propofol in terms of hemodynamic stability. However, it remains unclear whether remimazolam-based total intravenous anesthesia (TIVA) can reduce intraoperative hypotension compared to propofol-based TIVA, especially after prone positioning. In this study, we compared the effects of remimazolam- and propofol-based TIVA on intraoperative hemodynamic stability in patients undergoing surgery in the prone position. Materials and Methods: This study randomly assigned patients undergoing major spinal surgery in the prone position to the propofol or remimazolam group. Target-controlled infusion (2-3.5 µg/mL for induction and 2-3 µg/mL for maintenance) was used in the propofol group and continuous infusion (6 mg/kg/h for induction and 1-2 mg/kg/h for maintenance) was used in the remimazolam group; target-controlled infusion (3-5 ng/mL) of remifentanil was performed in both groups. The primary outcomes were the incidence of hypotensive episodes during the first hour after prone positioning. The secondary outcomes included the incidence of severe hypotension and the total amount of inotropic or vasopressor medication. Systolic and mean arterial pressure, heart rate, cardiac index and output, stroke volume, stroke volume variation, and pleth variability index were also evaluated. These variables were recorded per minute for the first 10 min after prone positioning, and every 10 min thereafter. Results: The study enrolled 94 patients (47 patients in each group). The incidence of hypotension or severe hypotension did not differ significantly between the two groups during the first hour after prone positioning. The total amount of ephedrine administered during the first hour after prone positioning was lesser (p = 0.020) and the mean arterial pressure during the initial 10 min after prone positioning was higher in the remimazolam group (p = 0.003). Conclusions: Our study uncovered no significant differences in the incidence of hypotension between remimazolam- and propofol-based TIVA in patients undergoing major spine surgery in prone position.

Evaluating the Clinical Utility of Brachial Plexus Block for Reducing Opioid Exposure in Pediatric Elbow Fracture Surgery: A Retrospective Cohort Study.

Background and Objectives: Reducing opioid exposure in common pediatric surgeries is of paramount importance. This study aimed to assess the efficacy of regional nerve blocks in reducing opioid exposure while preserving high success rates. Materials and Methods: We conducted a retrospective matched cohort study (1:1) including patients with elbow fractures < 12 years old who underwent treatment with percutaneous pinning. Patients were divided into general-anesthesia (GA) and GA-followed-by-supraclavicular-brachial-plexus-block (GA-SCB) groups. The primary outcome was the number of patients administered postoperative rescue opioids. The secondary outcomes included intraoperative and postoperative opioid administration, the time to first request for rescue analgesia, pain scores, block success rate, block performing time, and block-related complications. Results: In a total of 478 patients, 363 underwent percutaneous pinning, and 86 were cohort-matched (GA: n = 43, GA-SCB: n = 43). On the first postoperative day, 34 (79.0%) patients in the GA group were administered postoperative rescue opioids, compared with 12 (27.9%) in the GA-SCB group (p < 0.001). All the patients in the GA-SCB group were opioid-free during the intraoperative period. No SCB-associated complications were observed. Total opioid consumption was significantly lower in the GA-SCB group than in the GA group until the first postoperative day (GA vs. GA-SCB, 3.2 ± 3.0 mg vs. 0.9 ± 1.8 mg, p < 0.001). Conclusions: SCB application in pediatric patients who underwent elbow fracture surgery significantly reduced opioid exposure and had a high success rate when performed using ultrasound guidance by an expert. Furthermore, the complication risk and surgical delay were minimal.

Comparison of analgesic effect of pericapsular nerve group block and supra-inguinal fascia iliaca compartment block on dynamic pain in patients with hip fractures: a randomized controlled trial.

BACKGROUND: Patients with hip fracture often experience severe pain, particularly during movement or slight positional change, prior to the occurrence of surgery. It is essential to explore the appropriate analgesic methods before surgery in patients with hip fracture, especially those capable of alleviating dynamic pain. Pericapsular nerve group (PENG) block was introduced as a useful technique for hip analgesia. In this study, we aimed to compare the reduction in dynamic pain between the PENG block and supra-inguinal fascia iliaca compartment block (SIFICB). METHODS: This prospective trial included 80 hip fracture patients aged ≥19 years, with an American Society of Anesthesiologists Physical Status of 1-4 and a baseline dynamic pain score ≥4 on the numerical rating scale. The patients were randomly allocated into the PENG block (n=40) and SIFICB group (n=40). For the PENG block and SIFICB, 20 mL and 30 mL of 0.3% ropivacaine was used, respectively. The primary outcome was reduction in dynamic pain scores at 30 min following the peripheral nerve block. Dynamic pain score was evaluated when the leg was passively raised. RESULTS: A total of 79 patients were included in the final analysis, and the reductions in pain score during hip flexion were 3.1±2.4 and 2.9±2.5 in the PENG block and SIFICB groups, respectively, which was statistically insignificant (p=0.75). Moreover, no significant differences were observed in any of the outcomes. CONCLUSIONS: PENG block and SIFICB could effectively provide analgesia for dynamic pain in patients with hip fractures, with no significant difference between the two groups. TRIAL REGISTRATION NUMBER: NCT04677348.

Comparison of preemptive and preventive intravenous acetaminophen on opioid consumption in pediatrics undergoing posterior spinal fusion surgery: a randomized controlled trial.

BACKGROUND: Posterior spinal fusion (PSF), commonly used for adolescent idiopathic scoliosis (AIS), causes severe postoperative pain. Intravenous (IV) administration of acetaminophen has shown promise for opioid-sparing analgesia; however, its analgesic effect and optimal timing for its standard use remain unclear. Our study aimed to evaluate the analgesic effect and optimal timing of IV acetaminophen administration in pediatric and adolescent patients undergoing PSF and requiring adequate pain control. METHODS: This prospective, randomized, triple-blind trial was conducted in patients aged 11-20 undergoing PSF. Participants were randomized into three groups: the preemptive group (received IV acetaminophen 15 mg/kg after anesthetic induction/before surgical incision), the preventive group (received IV acetaminophen 15 mg/kg at the end of surgery/before skin closure), and the placebo group. The primary outcome was cumulative opioid consumption during the first 24 h postoperatively. RESULTS: Among the 99 enrolled patients, the mean ± standard deviation (SD) amount of opioid consumption during the postoperative 24 h was 60.66 ± 23.84, 52.23 ± 22.43, and 66.70 ± 23.01 mg in the preemptive, preventive, and placebo groups, respectively (overall P = 0.043). A post hoc analysis revealed that the preventive group had significantly lower opioid consumption than the placebo group (P = 0.013). However, no significant differences between the groups were observed for the secondary outcomes. CONCLUSIONS: The preventive administration of scheduled IV acetaminophen reduces cumulative opioid consumption without increasing the incidence of drug-induced adverse events in pediatric and adolescent patients undergoing PSF.