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 the Analgesic Efficacy between Arthroscopically Placed Continuous Suprascapular Nerve Block and Ultrasound-guided Continuous Superior Trunk Block: A Double-blinded Randomized Controlled Trial.

BACKGROUND: Single-shot suprascapular nerve block and superior trunk block have been reported to provide a noninferior analgesic effect after shoulder surgery with a lesser incidence of hemidiaphragmatic paresis compared with interscalene brachial plexus block. This study hypothesized that continuous suprascapular nerve block provides noninferior analgesia with minimal effects on diaphragmatic movement compared with continuous superior trunk block in patients undergoing arthroscopic shoulder surgery. METHODS: 100 patients were randomized undergoing arthroscopic shoulder surgery between December 2020 and October 2021 into continuous suprascapular nerve block and continuous superior trunk block groups. Before the surgery, patients received either a single-shot superior trunk block or subomohyoid suprascapular nerve block. Thereafter, a superior trunk catheter was inserted by anesthesiologists in patients in the continuous superior trunk block group, and a posterior suprascapular nerve catheter was inserted with arthroscopic assistance during the surgery by surgeon in the continuous suprascapular nerve block group. The primary outcome was the postoperative pain score at postoperative 24 h, and the incidence of hemidiaphragmatic paresis was also compared. RESULTS: Overall, 98 patients were included in the final analysis. The worst and resting pain scores at postoperative 24 h in the continuous suprascapular nerve block group were inferior compared with those in the continuous superior trunk block group in the test with a noninferiority margin of 1 (worst pain score: mean difference, 0.9; 95% CI, 0.1 to 1.7; resting pain score: mean difference, 0.5; 95% CI, 0.0 to 1.0). However, the continuous suprascapular nerve block group had a significantly lower incidence of hemidiaphragmatic paresis at postoperative 24 h than the continuous superior trunk block group. CONCLUSIONS: Continuous suprascapular nerve block provides statistically inferior analgesia compared to the continuous superior trunk block; however, the continuous suprascapular nerve block had a minimal effect on the phrenic nerve function.

A comparison of the continuous supraclavicular brachial plexus block using the proximal longitudinal oblique approach and the interscalene brachial plexus block for arthroscopic shoulder surgery: A randomised, controlled, double-blind trial.

BACKGROUND: Continuous interscalene brachial plexus block (ISB) is widely used for arthroscopic shoulder surgery, but the incidence of hemidiaphragmatic paresis (HDP) has been reported to reach 100%. Several methods, including injections distal to the C5-C6 nerve roots, have been attempted to reduce the HDP incidence. However, catheter placement distal to the C5-C6 nerve roots interferes with the surgical site. OBJECTIVE: Our primary objective was to describe a new technique, the supraclavicular brachial plexus block (SCB), using the proximal longitudinal oblique approach (PLO-SCB), which can facilitate catheter placement and, when compared with ISB, to test whether this would provide noninferior analgesia and spare the phrenic nerve. DESIGN: Prospective, randomised, double-blind study. SETTING: Operating rooms, postanaesthesia care unit, and wards. PATIENTS: Seventy-six patients aged 20 to 80 years scheduled for arthroscopic shoulder surgery. INTERVENTIONS: Patients were randomly assigned to the continuous PLO-SCB (n = 40) or the continuous ISB (n = 40) groups. All patients received an initial low-volume single-injection (5 ml 0.75% ropivacaine) followed by a patient-controlled infusion of 0.15% ropivacaine. MAIN OUTCOME MEASURES: The primary outcomes were the incidence of HDP and pain scores. Secondary outcomes were respiratory function, postoperative analgesic consumption, sensory and motor function, and complications. RESULTS: The HDP incidence was significantly lower in the PLO-SCB group than in the ISB group at 30 min after block injection: 0% (0 of 38 patients) and 73.7% (28 of 38 patients), respectively (P < 0.001). Similarly, at 24 h after surgery, the incidences were 23.7% (9 of 38 patients) and 47.4% (18 of 38 patients) in the PLO-SCB and ISB groups, respectively (P = 0.002). Median [IQR] NRS pain scores at rest measured after surgery in the ISB and PLO-SCB groups were similar: immediately after surgery, 1 [0 to 2] vs. 1 [0 to 1], P = 0.06); at 30 min, 2 [0.25 to 2] vs. 1 [0 to 2], P = 0.065); and at 24 h 2 [0.25 to 3] vs. 1 [0 to 3], P = 0.47, respectively. CONCLUSION: For major shoulder surgery, compared with continuous ISB, continuous PLO-SCB was more sparing of diaphragmatic and respiratory function while providing noninferior analgesia. Catheter placement via the PLO approach is feasible without interfering with the surgical field. TRIAL REGISTRATION: Registered by the Clinical Trial Registry of Korea (Seoul, Korea; KCT0004759, http: cris.nih.go.kr, principal investigator: Hyungtae Kim).

Interaction between Dexamethasone, Ropivacaine, and Contrast Media Used in Interventional Pain Treatment: Considerations in Safety.

Background and Objectives: Although epidural steroid injections are used as an effective treatment, this technique is associated with rare but serious ischemic complications, especially when particulate steroids are used. However, recent studies have reported that even if non-particulate steroids are used, particulates are formed by the interaction with some local anesthetics (LA), causing ischemic complications. This observational study evaluated commonly used combinations of non-particulate steroids and LA with contrast media via microscopic analysis and analyzed the chemical properties of each mixture to identify the correlation of particulate formation. Materials and Methods: Commonly used clinical non-particulate and particulate steroids, contrast media, and LA agent combinations were evaluated macroscopically and microscopically. The pH values were also measured at both room temperature (26 °C) and body temperature (36 °C). Where particulates were observed, the particulate size was measured. Results: Macroscopically, the mixture of non-particulate steroid and ropivacaine had a slightly cloudy appearance at all concentrations, but there was no visible particulate. However, when observed under a microscope, the pH-dependent particulate formation was observed at all concentration combinations tested. (0.1% ropivacaine: from 19 µm to 70 µm, and 0.2% ropivacaine: from 37 µm to 108 µm at room temperature (26 °C)). When contrast media was mixed or the temperature was raised to body temperature (36 °C), the number and size of the particulates decreased or dissolved. Conclusions: The combination of ropivacaine and dexamethasone, a non-particulate steroid, mainly used in epidural injections, forms particulates. However, when mixed with contrast media, particulates are dissolved because of changes in pH and factors affecting particulate formation. In fluoroscopy-guided injections, the use of contrast media could resolve particulate formation.

Comparison of General and Spinal Anaesthesia on Systemic Inflammatory Response in Patients Undergoing Total Knee Arthroplasty: A Propensity Score Matching Analysis.

Background and Objectives: Some of the postoperative complications following orthopaedic surgeries are associated with a systemic inflammatory response (SIR), which varies depending on the anaesthetic technique. We aimed to compare the effects of general and spinal anaesthesia on the SIR after total knee arthroplasty (TKA), based on C-reactive protein (CRP) levels, the platelet-lymphocyte ratio (PLR), and the neutrophil-lymphocyte ratio (NLR). Materials and Methods: Patients who underwent TKA between January 2014 and December 2018 were included. Electronic medical records of the patients were retrospectively reviewed and analysed. To reduce the impact of potential confounding factors, we performed propensity score matching according to the anaesthetic technique. Results: A total of 1311 TKA cases were analysed. After propensity score matching, the maximal CRP value and changes in CRP levels in the general anaesthesia group were higher than those in the spinal anaesthesia group. However, the maximal NLR and PLR and the changes in NLR and PLR were not different between the two groups. There were no differences in postoperative clinical outcomes. Conclusion: Spinal anaesthesia tended to induce a lower inflammatory response than general anaesthesia when considering CRP levels in patients undergoing TKA. However, the effects of anaesthetic techniques on the overall outcomes were not significant.

Ultrasound-Guided Anterior Approach to a Sciatic Nerve Block: Influence of Lower Limb Positioning on the Visibility and Depth of the Sciatic Nerve.

OBJECTIVES: We aimed to identify the optimal lower limb position for an ultrasound (US)-guided anterior approach to a sciatic nerve block. METHODS: We included 45 patients who met the following criteria: American Society of Anesthesiologists physical status of 1 to 3, age between 18 and 80 years, and scheduled to undergo knee surgery that required a sciatic nerve block. The lower limbs of each patient were placed in the following 4 positions: N, neutral; ER, external rotation of the hip (angle, 45°); ER/F15, ER (angle, 45°) and flexion (angle, 15°) of the hip; and ER/F45, ER (angle, 45°) and F (angle, 45°) of the hip. An investigator acquired US scans of the sciatic nerve in each position, and the visibility score and depth of the sciatic nerve from the skin were analyzed. RESULTS: The visibility scores were significantly higher in positions ER/F15 and ER/F45 than in positions ER and N (P < .0001). However, there was no difference between the visibility scores in positions ER/F15 and ER/F45 (P = .0959). The depth of the sciatic nerve from the skin decreased with ER and an increase in the F angle of the hip (overall P < .0001). CONCLUSIONS: Based on the visibility score and depth from the skin, ER of the hip to 45° with a greater F angle (45° versus 15°) of the hip appears to be the optimal position for an US-guided anterior approach to a sciatic nerve block.

Optimization of the Operating Room Scheduling Process for Improving Efficiency in a Tertiary Hospital.

Efficient operating room (OR) scheduling can improve OR utilization and reduce costs. We hypothesize that the scheduling office (ORSO) leading the modification scheduling process could increase OR utilization rate. Using retrospective data from a single tertiary hospital in two consecutive calendar years, we compared OR utilization rate, the number of daily cases and cumulative operative time in the pre- and post-implementation of scheduling process alteration. We operated about 100,609 cases in the OR during the study period. Daytime utilization rate increased from 85.6% to 89.4% (P < 0.001); overall OR utilization rate from 115.1% to 117.6% (P = 0.019); daily case numbers from 229.9 ± 7.3 to 239.6 ± 7.6 (P = 0.0.14); and cumulative operation time of total and daytime cases from 611.7 case-hour/day to 624.5 case-hour/day (P = 0.013) and from 510.8 case-hour/day to 533.8 case-hour/day (P < 0.001), respectively. Evening/night time case-hour significantly decreased from 100.9 case-hour/day to 90.7 case-hour/day (P < 0.001). The optimization of the scheduling process and coordination by the office during regular workhours resulted in enhanced OR efficiency. The OR scheduling office can act as a control tower to make OR management more flexible, which can improve efficiency and carry financial benefits in tertiary hospitals.

Effects of neuromuscular presynaptic muscarinic M1 receptor blockade on rocuronium-induced neuromuscular blockade in immobilized tibialis anterior muscles.

This in vivo study tested the hypothesis that the modulation of acetylcholine (ACh) release by the M1 muscarinic receptor (mAChR) in the neuromuscular junction of disused muscles may affect the tensions of the muscles during the neuromuscular monitoring of a rocuronium-induced neuromuscular block and compared the results with those obtained from normal muscles. A total of 20 C57BL/6 (wild-type) and 10 α7 knock out (α7KO) mice were used in this experiment. As a pre-experimental procedure, knee and ankle joints of right hind limbs were fixed by needle pinning at the 90° flexed position. After 2 weeks, the main experiment was performed. Both tendons of the tibialis anterior (TA) muscles were obtained, and the muscle tensions were recorded while the dose-responses of rocuronium were measured three times in the same mouse by the serial administration of pirenzepine (0, 0.001 and 0.01 µg/g). Weight losses were observed after 2 weeks of immobilization in both groups, and a decrease in the mass of TA muscles at the immobilized side was observed compared to those of the contralateral nonimmobilized side. Tension depression of the TA muscles at immobilized side of the α7KO group was faster than those of the wild-type group, but these differences decreased after the administration of pirenzepine. The tension depressions were similar regardless of the pirenzepine doses at the same side in the group. Tension depression may become more rapid in the α7 AChR-expressed disused muscles by the decreased release of ACh release upon neuronal firing by the blockade of facilitatory M1 mAChR.

Effects of presynaptic muscarinic cholinoreceptor blockade on neuromuscular transmission as assessed by the train-of-four and the tetanic fade response to rocuronium.

This study investigated the effect of muscarinic M1 and M2 receptor antagonists on the rocuronium-induced train of four (TOF) fade and tetanic fade, respectively. Ex-vivo phrenic nerves and diaphragms were obtained from adult Sprague-Dawley rats and stabilized in Krebs buffer; the nerve-stimulated muscle TOF fade was observed at 20 s intervals. For the TOF study, phrenic nerves and diaphragms were incubated with pirenzepine (an M1 blocker) at concentrations of 0 nmol L-1 (control), 10 nmol L-1 (PZP10), or 100 nmol L-1 (PZP100). Rocuronium was then administered incrementally until the first twitch tension had depressed by >95% during TOF stimulation. The mean TOF ratios were compared when the first twitch tensions were depressed by 40%-50%. For the tetanic fade study, 50 Hz/5 s tetani was applied initially, 30 min after the administration of a loading dose of rocuronium and methoctramine (an M2 receptor blocker, loaded at 0 µmol L-1 [control], 1 µmol L-1 [MET1], or 10 µmol L-1 [MET10]). The EC95 of rocuronium was significantly lower in the PZP10 group than in the control group. In the PZP10 group, the TOF ratios at 50% and first twitch tension depression were significantly lower than those in the control group (P=.02). During tetanic stimulation, the tetanic fade was significantly enhanced in the MET10 group compared to the other groups. This study shows that antagonists of muscarinic M1 and M2 receptors affect the rocuronium-induced neuromuscular block as demonstrated by the reduced EC95 and TOF ratios (M1 antagonist, pirenzepine) or the enhanced 50-Hz tetanic fade (M2 antagonist, methoctramine).

The neuromuscular effects of rocuronium under sevoflurane-remifentanil or propofol-remifentanil anesthesia: a randomized clinical comparative study in an Asian population.

BACKGROUND: We conducted a prospective, randomized, multicenter study to evaluate the differences in the blocking effect of different doses of rocuronium between sevoflurane- or propofol-remifentanil anesthesia in an Asian population. METHODS: A total of 368 ASA I-II patients was enrolled. Anesthesia was induced with 2.0 mg/kg propofol and 0.1 µg/kg/min remifentanil (TIVA) or 5.0 vol.% sevoflurane with 0.1 µg/kg/min remifentanil (SEVO). Tracheal intubation was facilitated at 180 s after the administration of rocuronium at 0.3, 0.6, or 0.9 mg/kg and then intubation condition was evaluated. The time to maximum block and recovery profile were monitored by TOF stimulation of the ulnar nerve and by recording the adductor pollicis response using acceleromyography. RESULTS: The numbers of patients with clinically acceptable intubation conditions were 41, 82, and 97 % (TIVA) and 34, 85, and 90 % (SEVO) at each dose of rocuronium, respectively. There were no significant differences in the time to maximum block between groups at each rocuronium dose. There were significant differences in the recovery to a train-of-four ratio of 90 % between the groups: 42.7 (19.5), 74.8 (29.9), and 118.4 (35.1) min (TIVA) and 66.5 (39.3), 110.2 (43.5), and 144.4 (57.5) min (SEVO) at 0.3, 0.6, and 0.9 mg/kg, respectively (P < 0.001). CONCLUSIONS: There are no significant differences in intubation conditions between propofol-remifentanil and sevoflurane-remifentanil anesthesia at the same dose of rocuronium. The type of anesthetic does not significantly influence the time to maximum block by rocuronium. Rocuronium at a dose of 0.9 mg/kg should be used for better intubation conditions with both anesthesia regimens in an Asian population. TRIAL REGISTRATION: UMIN-CTR Clinical Trial ( http://www.umin.ac.jp/ctr/index.htm ; UMIN#000007289 ; date of registration 14(th) February 2012).

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.

Association of C-reactive protein to albumin ratio with postoperative delirium and mortality in elderly patients undergoing hip fracture surgery: A retrospective cohort study in a single large center.

BACKGROUND: Postoperative delirium is a common complication in elderly patients who have undergone hip fracture surgery. Since postoperative delirium is associated with poor outcomes and the treatment is very complicated, identifying the patients at high risk for delirium and providing more attentive care to prevent postoperative delirium is essential. In this study, we aimed to assess the association of an elevated C-reactive protein (CRP)/albumin ratio with the increased incidence of postoperative delirium in elderly people who had undergone hip fracture surgery. METHODS: A total of 629 patients who underwent hip fracture surgery between January 2014 and December 2018 were retrospectively analyzed. Patients were classified into two groups according to preoperative CRP/albumin cut-off levels (<1.5 and ≥1.5). We performed a propensity score matching analysis to compare the incidence of postoperative delirium and overall mortality between the two groups. Multivariate logistic regression and Cox regression analyses were performed to examine the association of the preoperative CRP/albumin ratio with postoperative delirium and overall mortality. RESULTS: There were significant differences in the incidence of postoperative delirium (18.0 % vs. 35.8 %, P < 0.001) and overall mortality (26.7 % vs. 46.9 %, P < 0.001) between the groups before matching. We also observed significant differences in the incidence of postoperative delirium (20.7 % vs. 32.7 %, P = 0.019) and overall mortality (34.7 % vs. 46.0 %, P = 0.046) between the groups after matching. A high CRP/albumin ratio (≥1.5) was significantly associated with a higher incidence of postoperative delirium (adjusted odds ratio [OR]: 2.11, 95 % confidence interval [CI]: 1.40-3.18, P < 0.001) and a higher rate of overall mortality (adjusted hazard ratio [HR]: 1.44, 95 % CI: 1.07-1.93, P = 0.015). CONCLUSION: Preoperative CRP/albumin ratio might be an independent risk factor of postoperative delirium and surgical prognosis in elderly patients undergoing hip fracture surgery.

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

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

Change in the optic nerve sheath diameter after deflation of a pneumatic tourniquet: a prospective observational study.

Applying a pneumatic tourniquet provides surgeons with a bloodless surgical field. However, application of the tourniquet induces various physiological changes. We evaluated the effect of tourniquet deflation on the intracranial pressure by using ultrasonography to measure the optic nerve sheath diameter (ONSD) in patients undergoing lower limb surgery. The ONSD was measured in 20 patients at five time points: after anesthetic induction (T0) and immediately before (T1), immediately after (T2), 5 min after (T3), and 10 min after tourniquet deflation (T4). Hemodynamic and respiratory variables were recorded. The ONSD showed significant differences at each point (P < 0.001). The ONSDs at T2 and T3 were significantly greater than that at T1 (P = 0.0007 and < 0.0001, respectively). The change in the end-tidal carbon dioxide partial pressure (EtCO2) was similar to the change in the ONSD. The change in the ONSD was significantly correlated with the change in the EtCO2 after tourniquet deflation (r = 0.484, P = 0.030). In conclusion, the ONSD, as an indicator of intracranial pressure, increased after tourniquet deflation in patients undergoing lower limb surgery. This was correlated with an increased EtCO2 and arterial carbon dioxide partial pressure.Trial registration: ClinicalTrials.gov (NCT03782077).

Predicting Epidural Space Spread Using Ultrasound Color Doppler Imaging in Interlaminar Epidural Steroid Injection: A Prospective Observational Study.

BACKGROUND: While the use of fluoroscopy-guided transforaminal epidural steroid injection (TFESI) to help spread the injectate toward the ventral side has increased, this procedure has a radiation risk. Recently, ultrasound has been widely used in the medical field; among ultrasound methods, color Doppler is useful for predicting the direction of the injectate. OBJECTIVE: This study describes a novel technique employing color Doppler to help predict epidural space spread in interlaminar epidural steroid injection (ILESI). STUDY DESIGN: Prospective observational study. SETTING: The study took place at a single pain clinic within a medical center in Jeonju, Republic of Korea. METHODS: We enrolled 35 patients scheduled for lumbar epidural steroid injection (ESI).  Ultrasound-guided epidural lateral parasagittal interlaminar injection was performed and real-time images using color Doppler were recorded during injections of 5 mL of 0.1% ropivacaine containing contrast dye with dexamethasone 5 mg (1 mL). Fluoroscopy-guided TFESI was performed if it was difficult to perform the procedure based on ultrasound images. RESULTS: The analysis included 30 images from 30 patients. The observed sensitivity, specificity, positive predictive value, and negative predictive values of the ultrasound color Doppler were 100%, 89.5%, 84.6%, and 100%, respectively. The agreement with ultrasound color Doppler was 93.3%. LIMITATIONS: The sample size was relatively small. CONCLUSION: The main advantage of ultrasound-guided ILESI is the lack of radiation exposure and contrast medium requirement. Color Doppler may be a reliable imaging modality to predict epidural space spread during ultrasound-guided ILESI. It is worth predicting the spread in the anterior epidural space (AES) by first attempting ultrasound-guided ESI. If the injectate has not spread to the AES, fluoroscopy-guided TFESI may be a good option after confirming improvement of the patient's symptoms.

Initiation Timing of Continuous Interscalene Brachial Plexus Blocks in Patients Undergoing Shoulder Arthroplasty: A Retrospective Before-and-After Study.

A continuous interscalene brachial plexus block (CIBPB) is usually administered before surgery in awake patients. However, the use of CIBPB before surgery could hinder the identification of nerve injuries after total shoulder arthroplasty (TSA). This study aimed to compare the analgesic effects of preoperatively and postoperatively initiated CIBPBs in patients undergoing TSA. The medical records of patients who underwent TSA between January 2016 and August 2020 were retrospectively reviewed. The following analgesic phases were used: intravenous (IV) patient-controlled analgesia (PCA) phase (IV PCA group, n = 40), preoperative block phase (PreBlock group, n = 44), and postoperative block phase (PostBlock group, n = 33). The postoperative initiation of CIBPB after a neurologic exam provided better analgesia than IV PCA and had no differences with the preoperative initiation of CIBPB, except for the worst pain at the postanesthetic care unit. Opioid consumption was significantly greater in the IV PCA group, but there were no differences between the PreBlock and PostBlock groups on operation day after the transfer to the general ward. The initiation of CIBPB after a patient's emergence from general anesthesia had comparable analgesic efficacy with preoperative CIBPB but offered the chance of a postoperative neurologic exam.

Low Psoas Lumbar Vertebral Index Is Associated with Mortality after Hip Fracture Surgery in Elderly Patients: A Retrospective Analysis.

The psoas-to-lumbar index (PLVI) has been reported as a simple and easy way to measure central sarcopenia. However, only few studies have evaluated the association between PLVI and survival in surgical patients. This study evaluated the association between preoperative PLVI and mortality in elderly patients who underwent hip fracture surgery. We retrospectively analyzed 615 patients who underwent hip fracture surgery between January 2014 and December 2018. The median value of each PLVI was calculated according to sex, and the patients were categorized into two groups on the basis of the median value (low PLVI group vs. high PLVI group). Cox regression analysis was performed to evaluate the risk factors for 1 year and overall mortalities. The median values of PLVI were 0.62 and 0.50 in men and women, respectively. In the Cox regression analysis, low PLVI was significantly associated with higher 1 year (hazard ratio (HR): 1.87, 95% confidence interval (CI): 1.18-2.96, p = 0.008) and overall mortalities (HR: 1.51, 95% CI: 1.12-2.03, p = 0.006). Low PLVI was significantly associated with a higher mortality. Therefore, PLVI might be an independent predictor of mortality in elderly patients undergoing hip fracture surgery.