Nerve Block Research Articles

Ultrasound-Guided Nerve Blocks for Flexor Tenosynovitis

Performing an ultrasound-guided nerve block (UGNB) is now common practice in many emergency departments (EDs) and is considered a core skill according to the American College of Emergency Physicians (ACEP). Nerve blocks are mostly utilized for fractures and laceration repairs, however, these blocks have many other applications. We present a case of utilizing an ulnar UGNB in a patient with flexor tenosynovitis and a history of intravenous drug use (IVDU) when parental opiates proved to be ineffective.

Ultrasound-Guided Nerve Blocks Have the Potential to Reduce Racial and Ethnic Disparities in Emergency Department Pain Management

Ultrasound-Guided Nerve Blocks Have the Potential to Reduce Racial and Ethnic Disparities in Emergency Department Pain Management

Selective nociceptive modulation using a novel prototype of transcutaneous kilohertz high-frequency alternating current stimulation: a crossover double-blind randomized sham-controlled trial.

Kilohertz high-frequency alternating current (KHFAC) stimulation has demonstrated to induce rapid and reversible nerve blocks without causing nerve damage. Previous studies have explored frequency-dependent effects using a transcutaneous approach in humans from 5 to 20kHz. Nevertheless, its application in humans is limited by the lack of stimulators approved for frequencies above 20kHz. Therefore, this study aimed to assess the effects and safety of transcutaneous KHFAC stimulation using a novel prototype stimulator, comparing interventions at 30, 40, and 50kHz to sham stimulation on experimental pain, sensory, motor, and neurophysiological outcomes. A randomized, double-blind, sham-controlled crossover study involving 34 healthy participants was conducted. Four interventions (30, 40, 50kHz, and sham) were administered, and stimulation was applied for 20min to the median nerve of the non-dominant hand. A prototype stimulator capable of delivering frequencies between 1 and 50kHz, with a maximum peak-to-peak output current intensity of 400mA was designed. The intensity applied during the stimulation was below motor threshold, evoking a 'strong but comfortable' tingling sensation. Primary outcomes included heat pain threshold (HPT), pressure pain threshold (PPT), and adverse effects. The secondary outcomes included static two-point discrimination sensitivity, isometric pinch strength, and median sensory nerve action potential (SNAP). Compared with the sham stimulation, all the active interventions exhibited a significantly greater increase in the PPT during and immediately after the stimulation, while only a significant increase was observed at 40kHz (4.1N/cm2; 95%CI 0.3 to 7.9) at 15min post-intervention. Compared to sham stimulation, the 40kHz intervention had a significantly greater effect on the HPT at all time points, with the greatest difference (1.4°C; 0.6 to 2.1) occurring immediately post-intervention. Adverse effects during active interventions included petechiae, erythema, and itching, which resolved at 24h post-intervention. For secondary outcomes, only a significant reduction in the median SNAP velocity was observed in the sham stimulation group compared to the 50kHz group. Active KHFAC stimulation, particularly at 40kHz, delivered through a novel stimulator, effectively increased the PPT and HPT without affecting tactile or motor outcomes, inducing mild skin-related adverse effects. These findings have potential implications for people with pain-related pathologies. NCT05230836.

Study on the Analgesic Efficacy of Femoral Nerve Block for Post-Hip Arthroscopy Pain.

Postoperative pain management is challenging for hip arthroscopy, and the effectiveness and specific protocols of femoral nerve block (FNB) in hip surgeries remain insufficient. Therefore, we designed this study to investigate the analgesic efficacy and optimal drug concentrations of FNB after hip arthroscopy. A total of 148 patients undergoing hip arthroscopy were included and randomly divided into three groups: 0.3% ropivacaine FNB group, 0.4% ropivacaine FNB group, and 0.4% ropivacaine intra-articular injection (IAI) group (positive control). The main outcomes included dynamic and static visual analog scale (VAS) scores at various time points postoperatively, total intraoperative remifentanil consumption, and cumulative consumption of morphine within 24h postoperatively. Secondary outcomes included total intraoperative dexmedetomidine consumption, RASMAY sedation scores, and patients' satisfaction scores postoperatively. Both FNB and IAI anesthesia were shown to be safe for post-hip arthroscopy analgesia. Compared with IAI anesthesia, FNB showed no significant differences in analgesic effect within 12h postoperatively but had a better analgesic effect after 24h and lower remifentanil consumption intraoperatively. Group 0.4% ropivacaine showed lower dynamic VAS scores within the first 12h compared with 0.3% ropivacaine for FNB, however, there were no significant differences in patient satisfaction and sedation, and postoperative ambulation was delayed, indicating that the higher concentration of ropivacaine correlated with a longer time to ambulation. The IAI group had greater intraoperative opioid consumption and more side effects. Compared with IAI anesthesia, FNB can better alleviate post-hip arthroscopy pain and reduce opioid consumption. However, it requires specialized equipment and technical support and carries a certain risk of puncture. Chinese Clinical Trials Registry (ChiCTR2400091579).

Comparative Effects of Spinal Anesthesia and Combined Spinal with Peripheral Nerve Blocks on Postoperative Outcomes in Anterior Cruciate Ligament Repair

Objectives: This study aimed to compare the effectiveness of spinal anesthesia (SA) alone versus combined spinal anesthesia with adductor canal block (ACB) and sciatic nerve block (SNB) (SA + ACB + SNB) in patients undergoing arthroscopic anterior cruciate ligament (ACL) reconstruction. We hypothesized that SA + ACB + SNB would provide better analgesia, greater patient satisfaction, and shorter postanesthesia recovery times than SA alone. Methods: A prospective randomized controlled trial was conducted with 60 patients aged 15–49 years scheduled for elective arthroscopic ACL reconstruction. Participants were randomly assigned to receive either SA or SA + ACB + SNB. Postoperative pain was assessed using the Visual Analog Scale (VAS) at 4, 12, and 24 h post-operation. General health was evaluated using the 12-item Short Form Survey (SF-12) at 1 month postoperatively. Range of motion and analgesic consumption were also recorded. Results: The median VAS score at 4 h post-operation was significantly lower in the SA + ACB + SNB group compared to the SA group (0 [IQR: 0–1] vs. 2 [IQR: 1–3], p = 0.0137). No significant differences in VAS scores were found at 12 h (p = 0.9282) and 24 h (p = 0.5809). PCS-12 and MCS-12 scores did not differ significantly between groups. The SA group had a lower postoperative range of motion (ROM) compared to the SA + ACB + SNB group, with a mean active ROM of 40.67 degrees (±23.52) versus 72.17 degrees (±24.69), respectively (p < 0.0001). Analgesic consumption was similar, with 53.33% of participants in each group using postoperative analgesics (p = 1.0). The mean surgery duration was 74.6 min. The gender distribution was 83% male and 17% female, with an average age of 27.7 years. Conclusions: Adding ACB and SNB to spinal anesthesia improved immediate postoperative pain relief and preserved range of motion in patients undergoing ACL reconstruction, suggesting potential clinical benefits in pain management and functional recovery.

Capsaicin-Loaded Melanin Nanoparticles for Long-Lasting Nociceptive-Selective Nerve Blockade.

Clinically used amino-ester and amino-amide local anesthetics, such as bupivacaine and lidocaine, face two primary challenges: inadequate duration of action and nonselective action on both sensory and motor neurons, resulting in motor function loss alongside pain relief. In this work, we developed capsaicin-loaded melanin nanoparticles (Cap-MNPs) to address these two challenges. Capsaicin selectively acts on sensory neurons without affecting motor neurons, thereby achieving nociceptive-selective nerve blockade. Melanin is known for its exceptional biocompatibility, biodegradability, and abundance in pigmented human tissue. Melanin's inherent chemical structure and hydrophobic nature enable the encapsulation and sustained release of amino-ester and amino-amide local anesthetics with aromatic rings through π-π interactions and hydrophobic interactions. The drug loading efficiency of Cap-MNPs was 82.99 ± 1.55%, the drug loading capacity was 67.47 ± 4.24%, and capsaicin was continuously released for more than 360 h. In rats, a single injection of Cap-MNPs containing 8.04 mg of capsaicin produced a sciatic sensory nerve block lasting for 6 h without causing any local toxicity and capsaicin-related systemic toxicity. Cap-MNPs show promise as clinically useful therapeutics for pain management.

Axonal sensitivity and block dynamics

The role of differential nerve block in the development of analgesia after erector spinae plane block has been questioned. While highly myelinated nerves are more sensitive to local anesthetics than unmyelinated ones in vitro, factors influencing drug diffusion, particularly pKa, are more relevant in the clinical setting. Bupivacaine (the drug most used for an ‘analgesic’ effect) has a relatively high pKa (8.1), and only 15% of it is present in the lipid permeant, unionized form at pH 7.4 so it will penetrate unmyelinated C fibers relatively easily, but the myelin sheaths around other fiber types are a significant barrier to drug diffusion. The greater sensitivity of myelinated axons to local anesthetic action will only be apparent if the drug can reach their membranes in significant concentrations. In the very dynamic situation pertaining to a local anesthetic injection (no matter the site), diffusion factors mean that the concentration of the drug around the axons is likely to be very low and may result in an effect on unmyelinated fibers only.

Complication Rates After Ultrasonography-Guided Nerve Blocks Performed in the Emergency Department.

Ultrasonography-guided nerve blocks (UGNBs) have become a core component of multimodal analgesia for acute pain management in the emergency department (ED). Despite their growing use, national adoption of UGNBs has been slow due to a lack of procedural safety in the ED. To assess the complication rates and patient pain scores of UGNBs performed in the ED. This cohort study included data from the National Ultrasound-Guided Nerve Block Registry, a retrospective multicenter observational registry encompassing procedures performed in 11 EDs in the US from January 1, 2022, to December 31, 2023, of adult patients who underwent a UGNB. UGNB encounters. The primary outcome of this study was complication rates associated with ED-performed UGNBs recorded in the National Ultrasound-Guided Nerve Block Registry from January 1, 2022, to December 31, 2023. The secondary outcome was patient pain scores of ED-based UGNBs. Data for all adult patients who underwent an ED-based UGNB at each site were recorded. The volume of UGNB at each site, as well as procedural outcomes (including complications), were recorded. Data were analyzed using descriptive statistics of all variables. In total, 2735 UGNB encounters among adult patients (median age, 62 years [IQR, 41-77 years]; 51.6% male) across 11 EDs nationwide were analyzed. Fascia iliaca blocks were the most commonly performed UGNBs (975 of 2742 blocks [35.6%]). Complications occurred at a rate of 0.4% (10 of 2735 blocks). One episode of local anesthetic systemic toxicity requiring an intralipid was reported. Overall, 1320 of 1864 patients (70.8%) experienced 51% to 100% pain relief following UGNBs. Operator training level varied, although 1953 of 2733 procedures (71.5%) were performed by resident physicians. The findings of this cohort study of 2735 UGNB encounters support the safety of UGNBs in ED settings and suggest an association with improvement in patient pain scores. Broader implementation of UGNBs in ED settings may have important implications as key elements of multimodal analgesia strategies to reduce opioid use and improve patient care.

Comprehensive Pain Management in Total Joint Arthroplasty: A Review of Contemporary Approaches

Background: Total hip and knee arthroplasties are among the most effective and widely performed procedures in modern medicine, providing substantial benefits to patients with end-stage osteoarthritis. These surgeries have transformed the treatment of degenerative joint disease, significantly enhancing functionality and quality of life for patients. Despite considerable advancements in surgical techniques and postoperative care, managing postoperative pain remains a major challenge, impacting both clinical recovery and patient satisfaction. The persistence of postoperative pain as a barrier to recovery underscores the need for improved pain management strategies. Methods: A comprehensive narrative review of the literature was conducted, focusing on the physiological mechanisms underlying surgical pain, the role of anesthesia techniques, and the development of multimodal pain management approaches used in total joint arthroplasty. This review emphasizes the components of modern multimodal strategies, which combine multiple pharmacologic and non-pharmacologic methods to address the various mechanisms of postoperative pain. Results: Current pain management strategies employ a dynamic, multimodal approach that covers the perioperative period. These strategies aim to optimize pain control while minimizing side effects. They incorporate a range of methods, including nerve blocks, non-opioid analgesics, opioids, and non-pharmacologic techniques such as physical therapy. However, evidence regarding the efficacy and optimal combinations of these interventions varies widely across studies. Conclusions: This variation has led to inconsistent pain management practices across institutions. To standardize and improve care, this paper presents the authors’ institutional pain management model, offering a potential framework for broader application and adaptation in the field of joint arthroplasty.

Ultrasound-guided suprascapular nerve block with lidocaine vs. saline combined with physical exercises for the rehabilitation of supraspinatus tendinitis: a randomized double-blind controlled trial

IntroductionShoulder pain is the third leading cause of musculoskeletal complaints in primary care clinics. Its prevalence varies from 14% to 34%. Among all the structures that can cause shoulder pain, the most vulnerable to injury is the tendon of the supraspinatus muscle. The ideal management protocol is still unknown. To date, little is known in the literature about the use of ultrasound-guided suprascapular nerve block as a treatment for supraspinatus muscle tendinitis. Our objective was to assess the effects of the association of a single ultrasound-guided suprascapular nerve block combined with home-based rotator cuff exercises to reduce pain and improve shoulder functioning in patients with supraspinatus tendinitis.MethodsWe evaluated the effect of a single ultrasound-guided suprascapular nerve block on pain and functioning of people with supraspinatus tendinitis. Diagnosis was performed using the positive Jobe test. Due to large disparity between clinical and radiological findings, only clinical diagnostic criteria were used to select patients. This was a double-blind, randomized, controlled, clinical study in which patients in the intervention group (n = 42) received a single injection of 5 ml of 2% lidocaine, while in the control group (n = 41) patients underwent the same procedure receiving saline solution 0.9%. All patients received face to face instructions by an experienced physiotherapist and a leaflet explaining home-based exercises. Pain and functioning were assessed using the Shoulder Pain and Disability Index (SPADI) questionnaire before the procedure, one week and 12 weeks after the procedure.ResultsPatients in both groups improved significantly since the initial evaluation until the 12th week. Intervention group SPADI (pre, 1 week, 12 weeks): 75.80 ± 18.96, 56.25 ± 31.37, 46.31 ± 31.41 (p < 0.001); Control group SPADI: 75.49 ± 16.67, 50.51 ± 27.58, 49.37 ± 30.90 (p < 0.001). However, there were no significant differences between groups (p = 0.291).Discussion/conclusionWe concluded that both lidocaine and saline ultrasound-guided suprascapular nerve blocks reduce pain and improve shoulder functioning in patients with supraspinatus tendinitis. Unexpectedly, the same block performed with saline showed similar results and effects. Clinical Trial RegistrationClinicalTrials.gov, identifier [NCT02495818].

Abstract 4145819: Reducing the Burden of the Opioid Epidemic by Adopting a Novel Pain Control Strategy Utilizing Pectoral Nerve Block in Adults Undergoing Transvenous Cardiac Device Implants

Introduction: Despite early mitigation efforts, the opioid pandemic in the United States has persisted and affected many Americans. A public health emergency was declared urging all prescribers to use caution in prescribing opioids. Alternative approaches to postoperative pain management during transvenous cardiac device implants (TCDI) in adults have not been described. Methods: We report a single-center retrospective analysis of 612 consecutive patients that underwent TCDI between January 2021 and January 2024 with ultrasound guided pectoral nerve block (PNB) using liposomal bupivacaine prior to implant for postoperative pain management. Pain scores (0-10) were recorded systematically in the postoperative period, at discharge, and at wound check follow-up. Any need for opioid use in the postoperative period was recorded as well. Results: A total of 612 patients were evaluated, 50% female with a mean age of 71.2 years. All patients received PNB successfully with no device site infection or hematomas. The mean Visualized Analog Scale (VAS) pain scores at 1, 3, and 5 hours after the procedure, at discharge, and at the follow-up visit were 1.93, 1.22, 1.10, 1.05, and 0.13 respectively. During follow-up, no patients required opioids for pain control throughout the entire postoperative period of 14 days. Conclusion: Pectoral nerve block with liposomal bupivacaine can be performed safely preoperatively during TCDI and provides adequate pain control without need for opioid use postoperatively. Further research is needed to assess broad scale implications of this approach to larger patient populations.

Emerging Trends in Regional Anesthesia Techniques

Regional anesthesia has become an essential component of modern perioperative care, offering targeted pain relief, reducing opioid consumption, and enhancing recovery. Recent advancements in regional anesthesia techniques, particularly the adoption of ultrasound guidance, the development of novel nerve blocks, and the use of continuous catheter infusions, have significantly improved the precision, efficacy, and safety of these procedures. This article provides a comprehensive review of the emerging trends in regional anesthesia, including the latest techniques, clinical applications, and future directions. The integration of these advancements into clinical practice has the potential to further optimize patient outcomes, reduce perioperative complications, and enhance overall patient satisfaction.

Comparison of different techniques used for inferior alveolar nerve block anaesthesia regarding the pain caused in cooperative children.

The aim of this study is to compare the application of inferior alveolar nerve block (IANB) anaesthesia in children with traditional plastic syringe (TPS) and computer-controlled injection device Dentapen® using two different modes [continuous mode (DC) and ramp-up mode (DR)] in terms of pain. This study included 96 children aged 7-12 who were determined to be positive (3) or definitely positive (4) according to the Frankl Behaviour Evaluation Scale and in need of treatment who had IANB anaesthesia indication in the right and left regions. Patients were divided into three groups and compared in terms of pain felt during IANB anaesthesia according to heart rate, oxygen saturation, Wong Baker Pain Rating Scale, Face Legs Activity Cry Consolability Pain Scale and patient preference distributions. Heart rate values increased significantly during the injection of IANB anaesthesia with all methods [TPS, DC and DR methods (p < 0.05)]. No significant differences were found in terms of pain between the TPS, DC and DR methods in the intragroup and intergroup assessments. However, among the patient preferences of TPS and DC methods, the number of patients who preferred the DC method was found to be statistically significantly higher those who preferred the TPS method (p = 0.026). Although the TPS group scored higher than the Dentapen® groups in terms of pain, the difference between the investigated IANB anaesthesia techniques was not statistically significant. However, the majority of the patients preferred the Dentapen® device compared to the TPS. It appears that more research is needed on the Dentapen® device in local anaesthesia applications in children.

Comparative Efficacy of Postoperative Pain Management Techniques Following Costal Cartilage Harvest: A Systematic Review and Network Meta-analysis.

Efficient pain control is essential in reconstructive surgeries, particularly in procedures involving the harvest of costal cartilage. This study examines and compares different pain relief treatments using a network meta-analysis (NMA) to determine the most effective techniques for managing pain. We performed a systematic review and network meta-analysis (NMA) by scanning several databases such as PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), China National Knowledge Infrastructure (CNKI), Wanfang, and Weipu till March 18, 2024. The review analyzed randomized controlled trials and observational studies that evaluated the effectiveness of local anesthetics and multimodal analgesia techniques in treating postoperative pain following costal cartilage harvest. Primary outcomes were pain scores at 6-, 12-, 24-, and 48-h post-surgery, while secondary outcomes included the need for rescue analgesia and opioid-related adverse effects. Fourteen studies involving 935 participants were included. The analysis revealed that multimodal strategies, particularly 'Methylene Blue and Ropivacaine Intercostal Nerve Block (MB & Ropivacaine ICNB) combined with Patient-Controlled Analgesia (PCA),' were the most effective techniques to reduce pain scores across 6, 24, and 48-h time points. "Pre-operation SAPB & PSB + PCA" was most effective in reducing pain score at 12h and significantly decreased the need for rescue analgesia and opioid-related adverse effects. In contrast, traditional ICNB with single drug consistently showed the least efficacy. The results of our study strongly support the use of multimodal analgesic techniques instead of typical single medication ICNB for managing postoperative pain after costal cartilage harvest. These strategies not only provide superior pain control but also contribute to reducing the dependency on opioids, aligning with current clinical priorities to enhance recovery and minimize opioid-related risks. This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Articaine Versus Mepivacaine in Inferior Alveolar Nerve Block for Patients With Irreversible Pulpitis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Inferior alveolar nerve block (IANB) as an anesthetic strategy has shownconflicting results in terms of efficacy in the treatment of patients with irreversible pulpitis. Mepivacaine and articaine are anesthetic agents commonly used in the IANB technique for pulpal anesthesia. This review aimed to compare mepivacaine and articaine regarding pain and success rate. We conducted a search on the databases PubMed, Scopus, Web of Science (WOS), and Cochrane Central for randomized controlled trials (RCTs) assessing mepivacaine versus articaine until September 2024. The primary outcome of interest was success rate, while the secondary outcomes were pain intensity assessed by a 10-point visual analog scale (VAS) and incidence of severe pain. Data were pooled as odds ratio (OR) or mean difference (MD) with 95% confidence interval (CI) in a random-effect model using STATA. Five RCTs including 568 patients were included in the final analysis. While there was no significant difference between the two studied groups regarding the success rate (OR: 0.92, 95% CI: 0.69 to 1.21, p=0.54), articaine significantly reduced the pain intensity compared to mepivacaine (MD: 0.59, 95% CI: 0.31 to 0.86], p<0.001). Moreover, no significant difference was observed regarding the incidence of severe pain. Articaine reduced the intensity of pain post-procedure, with comparable results regarding success rate and incidence of severe painwith mepivacaine. Further large-volume RCTs are warranted to study the differences between the two options in the long term.

Characterization of Gingival Epulis Lesions: A Histological and Morphological Approach

Objective: To conduct a clinical and histopathological study of Epulis at Bhittai medical and Dental College, Mirpurkhas. Methodology: A descriptive cross-sectional study was carried out at the Bhittai medical and Dental College Mirpurkhas. Patients clinically diagnosed with gingival outgrowth, across all age groups and both genders, were included. A provisional diagnosis of epulis was made based on clinical examination. After taking a careful history, relevant clinical features were recorded, and a biopsy procedure was performed using infiltration near the lesion or regional nerve block techniques. The data was documented using a pre-designed proforma and analyzed using SPSS version 22.0. Results: Out of 50 subjects, 30 (60%) were female and 20 (40%) were male. Most cases involved the maxillary gingiva (anterior or posterior) (62%). The majority of lesions measured between 2cm and 3cm (76%). Lesions typically exhibited a soft consistency (70%), with fewer cases being firm (8%) or hard (22%). Histologically, peripheral giant cell granuloma (PG) was most prevalent (50%), followed by fibrous epulis (42%), peripheral ossifying fibroma (4%), and peripheral giant cell granuloma with features of central giant cell granuloma (PGCG) (4%). No cases of congenital epulis or pregnancy tumor were reported. Histological evaluation revealed no significant gender differences (p-value 0.86). Conclusion: Clinically, most epulis lesions presented as painless, soft, coral pink masses, typically measuring approximately 2-3 cm in diameter and exhibiting a sessile form and observed more commonly in females, with a predominant occurrence in the maxillary region. Histopathological examination revealed that the most frequent types were fibrous epulis and peripheral giant cell granuloma.

A Phase I Study of the Pharmacokinetics, Pharmacodynamics, and Safety of Liposomal Bupivacaine for Sciatic Nerve Block in the Popliteal Fossa for Bunionectomy.

This trial assessed the pharmacokinetics, pharmacodynamics, and safety of liposomal bupivacaine given via ultrasound-guided popliteal sciatic nerve block with or without immediate-release bupivacaine hydrochloride in adults having bunionectomies. Forty-five adults were enrolled into four sequential cohorts: (1) liposomal bupivacaine 266 mg with bupivacaine hydrochloride 50 mg; (2) liposomal bupivacaine 133 mg with bupivacaine hydrochloride 50 mg; (3) liposomal bupivacaine 266 mg; or (4) bupivacaine hydrochloride 100 mg. Outcomes included pharmacokinetics (e.g., bupivacaine maximum plasma concentration [Cmax]), onset and duration of motor and sensory nerve block, and safety. Liposomal bupivacaine admixed with bupivacaine hydrochloride produced biphasic bupivacaine plasma disposition profiles with two distinct peaks. Geometric mean Cmax of the early peak ranged from 235 to 421 ng/mL and the geometric mean of the late Cmax was ∼30%-50% lower than the early peak. Median time to sensory block onset was 18 to 29 min in all cohorts. Sensory blocks lasted about twice as long with liposomal bupivacaine (median, 119-167 h) than with bupivacaine hydrochloride alone (median, 67 h). There were no serious adverse events. In conclusion, liposomal bupivacaine provided prolonged sensory nerve block when given as popliteal sciatic nerve blocks with or without bupivacaine hydrochloride, and bupivacaine plasma concentrations were well below the lower bound of the toxicity threshold of 2000 ng/mL for all cohorts.

Back to the Future: Historic Insights and Recent Innovations in Pediatric Regional Anesthesia

Pediatric regional anesthesia is evolving with new peripheral nerve blocks and techniques aimed at improving perioperative pain management. While caudal blocks have long been standard due to their simplicity and low complication rates, newer fascial plane blocks offer comparable efficacy with enhanced nerve coverage tailored to specific surgeries. Moreover, adjuncts like dexmedetomidine and dexamethasone have shown promise in prolonging block duration and enhancing post-operative pain relief and patient satisfaction. The integration of these advancements into clinical practice has yielded significant benefits, including reduced intraoperative fluid requirements, decreased reliance on opioids postoperatively, earlier initiation of enteral nutrition, lower readmission rates, shorter hospital stays, and decreased overall hospital costs. Our review underscores the technical progress and expanding literature supporting the rapid adoption of these impactful regional anesthesia techniques in pediatric care.

Effect of ultrasound-guided internal branch of superior laryngeal nerve block on postoperative sore throat induced by a NIM-EMG-ETT: study protocol for a double-blinded randomized controlled trial

BackgroundPostoperative sore throat (POST) is a common complaint after general anaesthesia. The prevalence of POST caused by a neural integrity monitor electromyography endotracheal tube (NIM-EMG-ETT) is high. This study aimed to determine whether ultrasound-guided internal branch of superior laryngeal nerve block (iSLNB) could alleviate POST associated with a NIM-EMG-ETT.MethodsThis randomized controlled trial plans to enroll 182 patients scheduled to undergo general anaesthesia with a NIM-EMG-ETT. Patients will be randomly allocated into the iSLNB group or the control group according to randomized numbers generated by Excel. After induction, patients in the iSLNB group will undergo ultrasound-guided iSLNB with ropivacaine, and patients in the control group will undergo the same procedure with normal saline. The prevalence, severity, visual analogue scale score of POST, and postoperative acoustic analysis will be recorded.DiscussionTo the best of our knowledge, this is the first study to evaluate the effect of ultrasound-guided iSLNB with ropivacaine on the mitigation of POST induced by NIM-EMG-ETT. Our study will provide clinical answers to alleviate POST induced by NIM-EMG-ETT. The results of this study may provide a safe method to prevent POST caused by NIM-EMG-ETT.Trial registrationChinese Clinical Trial Registry, ChiCTR2300076393. Registered on October 24, 2023, http://www.chictr.org.cn/index.aspx.

Paravertebral versus Pectoralis-II (Interpectoral and Pectoserratus) Nerve Blocks for Postoperative Analgesia after Nonmastectomy Breast Surgery: A Randomized, Controlled, Observer-masked Noninferiority Trial.

Pectoralis-II and paravertebral nerve blocks are both used to treat pain after breast surgery. Most previous studies involving mastectomy identified little difference of significance between the two approaches. Whether this is also accurate for nonmastectomy procedures remains unknown. Participants undergoing uni- or bilateral nonmastectomy breast surgery anticipated to have at least moderate postoperative pain were randomized to a pectoralis-II or paravertebral block (90 mg ropivacaine per side for both). Surgeons and recovery room staff were masked to treatment group assignment, and participants were not informed of their treatment group. Injectate for pectoralis-II blocks was ropivacaine 0.3% (30 ml) per side. Injectate for paravertebral blocks was ropivacaine 0.5% (9 ml in each of two levels) per side. This study hypothesized that pectoralis-II blocks would have noninferior analgesia (numeric rating scale) and noninferior cumulative opioid consumption within the operating and recovery rooms combined (dual primary outcomes). The study was adequately powered with n = 100, but the target enrollment was raised to n = 150 to account for higher-than-anticipated variability. The trial was ended prematurely with 119 (79%) of the original target of 150 participants enrolled due to (masked) surgeon preference. Within the recovery room, pain scores were higher in participants with pectoralis-II (n = 60) than paravertebral blocks (n = 59): median [interquartile range], 3.3 [2.3, 4.8] versus 1.3 [0, 3.6] (95% CI, 0.5 to 2.6; P < 0.001). Similarly, intravenous morphine equivalents were higher in the pectoralis-II group: 17.5 [12.5, 21.9] versus 10.0 mg [10, 20] (95% CI, 0.1 to 7.5; P = 0.004). No block-related adverse events were identified in either group. After nonmastectomy breast surgery, two-level paravertebral blocks provided superior analgesia and opioid sparing compared with pectoralis-II blocks. This is a contrary finding to the majority of studies in patients having mastectomy, in which little significant difference was identified between the two types of blocks.