Dexmedetomidine Prolongs Lidocaine Intravenous Regional Anesthesia in Rats by Blocking the Hyperpolarization-Activated Cation Current.

Purpose: Intravenous regional anesthesia (IVRA) using lidocaine provides effective localized analgesia but its duration is limited. The mechanism by which dexmedetomidine enhances lidocaine IVRA is unclear but may involve modulation of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels. Materials and Methods: Lidocaine IVRA with varying dexmedetomidine concentrations was performed in the tails of Sprague-Dawley rats. Tail-flick and tail-clamping tests assessed IVRA analgesia and anesthesia efficacy and duration. Contributions of α2 adrenergic receptors and HCN channels were evaluated by incorporating an α adrenergic receptor antagonist, the HCN channel inhibitor ZD7288, and the HCN channel agonist forskolin. Furthermore, whole-cell patch clamp electrophysiology quantified the effects of dexmedetomidine on HCN channels mediating hyperpolarization-activated cation current (Ih) in isolated dorsal root ganglion neurons. Results: Dexmedetomidine dose-dependently extended lidocaine IVRA duration and analgesia, unaffected by α2 receptor blockade. The HCN channel inhibitor ZD7288 also prolonged lidocaine IVRA effects, while the HCN channel activator forskolin shortened effects. In dorsal root ganglion neurons, dexmedetomidine concentration-dependently inhibited Ih amplitude and shifted the voltage-dependence of HCN channel activation. Conclusion: Dexmedetomidine prolongs lidocaine IVRA duration by directly inhibiting HCN channel activity, independent of α2 adrenergic receptor activation. This HCN channel inhibition represents a novel mechanism underlying the anesthetic and analgesic adjuvant effects of dexmedetomidine in IVRA.

Anesthetic Considerations in Combined TAVR and Aortic Endovascular Procedures, a Case Report.

ABSTRACT: We report a case of simultaneous transcatheter aortic valve replacement and endovascular aneurysm repair. Our aim was to advocate the role of local and regional anesthesia as a key contributor in maintaining hemodynamic stability and avoiding abrupt blood pressure change. Endovascular combined procedures are gaining popularity for their numerous advantages. Nevertheless, they carry significant risks for their hemodynamic implications. It is imperative to acknowledge the modifications occurring after each correction and act accordingly. Different anesthesia approaches can dramatically influence hemodynamics; among all, we found local and regional anesthesia would better serve this objective.

Pecto-intercostal Fascial Plane Block: A Novel Technique for Analgesia in Patients with Sternal Dehiscence.

ABSTRACT: Sternal wound complications following sternotomy need a multidisciplinary approach in high-risk postoperative cardiac surgical patients. Poorly controlled pain during surgical management of such wounds increases cardiovascular stress and respiratory complications. Multimodal analgesia including intravenous opioids, non-opioid analgesics, and regional anesthesia techniques, like central neuraxial blocks and fascial plane blocks, have been described. Pecto-intercostal fascial plane block (PIFB), a novel technique, has been effectively used in patients undergoing cardiac surgery. Under ultrasound (US) guidance PIFB is performed with the aim of depositing local anesthetic between two superficial muscles, namely the pectoralis major muscle and the external intercostal muscle. The authors report a series of five cases where US-guided bilateral PIFB was used in patients undergoing sternal wound debridement. Patients had excellent analgesia intraoperatively as well as postoperatively for 24 hours with minimal requirement of supplemental analgesia. None of the patients experienced complications due to PIFB administration. The authors concluded that bilateral PIFB can be effectively used as an adjunct to multimodal analgesia with general anesthesia and as a sole anesthesia technique in selected cases of sternal wound debridement.

Is Tourniquet Pain the Result of Increased Compartment Pressure in the Forearm?

ABSTRACT: The pneumatic tourniquet has been a mainstay in upper extremity surgery by allowing the surgeon to operate in a blood-free field. Many upper extremity surgical procedures are done under local anesthesia or minimal sedation, and the problem of tourniquet pain is a vexing one. The question is posed: Is tourniquet pain the result of increased compartment pressure in the forearm? This study measured compartment pressures of the volar forearm in 10 healthy normotensive volunteers before inflation of a pneumatic tourniquet and compared it with pressure measurements taken while the tourniquet was still inflated after 15 minutes. Compartment pressures were measured using a Stryker needle manometer; all measurements were taken in the volar forearm by the senior author (C.H.M.). There was no increase in the volar/flexor compartment pressure of the forearm after 15 minutes of tourniquet inflation. All subjects complained of pain of the forearm, characteristically what is commonly called "tourniquet pain." We therefore conclude that in the upper extremity, at least for relatively short operating times, appropriate inflation of a tourniquet does not induce the early onset of increased compartment pressure in the forearm.

Short-term outcomes after selective shunt during carotid endarterectomy: A propensity score matching analysis / Resultados a corto plazo después de shunting selectivo durante la endarterectomía carotídea con anestesia regional: un análisis de propensity score-matching

Introduction and objectives: Carotid cross-clamping during carotid endarterectomy might lead to intraoperative neurologic deficits, increasing stroke/death risk. If deficits are detected, carotid shunting has been recommended to reduce the risk of stroke. However, shunting may sustain a specific chance of embolic events and subsequently incurring harm. Current evidence is still questionable regarding its clear benefit. The aim is to determine whether a policy of selective shunt impacts the complication rate following an endarterectomy. Material and methods: From January 2013 to May 2021, all patients undergoing carotid endarterectomy under regional anesthesia with intraoperative neurologic alteration were retrieved. Patients submitted to selective shunt were compared to a non-shunt group. A 1:1 propensity score matching (PSM) was performed. Differences between the groups and clinical outcomes were calculated, resorting to univariate analysis. Results: Ninety-eight patients were selected, from which 23 were operated on using a shunt. After PSM, 22 non-shunt patients were compared to 22 matched shunted patients. Concerning demographics and comorbidities, both groups were comparable to pre and post-PSM, except for chronic heart failure, which was more prevalent in shunted patients (26.1%, P=0.036) in pre-PSM analysis. Regarding 30-day stroke and score Clavien–Dindo≥2, no significant association was found (P=0.730, P=0.635 and P=0.942, P=0.472, correspondingly, for pre and post-PSM). Conclusions: In this cohort, resorting to shunting did not demonstrate an advantage regarding 30-day stroke or a Clavien–Dindo≥2 rates. Nevertheless, additional more extensive studies are mandatory to achieve precise results concerning the accurate utility of carotid shunting in this subset of patients under regional anesthesia.(AU)

Introducción y objetivos: El pinzamiento carotídeo durante la endarterectomía carotídea podría provocar déficits neurológicos intraoperatorios, lo que aumenta el riesgo de accidente cerebrovascular/muerte. Si se detectan déficits, se ha recomendado la derivación carotídea para reducir el riesgo de accidente cerebrovascular. Sin embargo, la derivación puede sostener una posibilidad específica de eventos embólicos y, posteriormente, provocar daños. La evidencia actual aún es cuestionable con respecto a su claro beneficio. El objetivo es determinar si una política de derivación selectiva afecta la tasa de complicaciones después de una endarterectomía. Material y métodos: Desde enero de 2013 hasta mayo de 2021 se recuperaron todos los pacientes sometidos a endarterectomía carotídea bajo anestesia regional con alteración neurológica intraoperatoria. Los pacientes sometidos a derivación selectiva se compararon con un grupo sin derivación. Se realizó una coincidencia de puntuación de propensión (PSM) 1:1. Se calcularon las diferencias entre los grupos y los resultados clínicos recurriendo al análisis univariado. Resultados: Se seleccionaron 98 pacientes, de los cuales 23 fueron intervenidos mediante derivación. Después de la PSM se compararon 22 pacientes sin derivación con 22 pacientes emparejados con derivación. Con respecto a la demografía y las comorbilidades, ambos grupos fueron comparables a los de antes y después de la PSM, excepto por la insuficiencia cardíaca crónica, que fue más prevalente en los pacientes con derivación (26,1%, p=0,036) en el análisis previo a la PSM. En cuanto al accidente cerebrovascular a los 30 días y la puntuación de Clavien-Dindo≥2, no se encontró asociación significativa (p=0,730, p=0,635 y p=0,942, p=0,472, correspondientemente, para pre y post-PSM). Conclusiones: En esta cohorte recurrir a la derivación no demostró una ventaja con respecto a las tasas de ictus a los 30 días o Clavien-Dindo≥2...(AU)

Desplazamiento de los catéteres para bloqueo continuo del nervio supraescapular tras fisioterapia: estudio en cadáveres / Dislodgment of continuous suprascapular nerve block catheters after physiotherapy: A cadaver study

Antecedentes: Los bloqueos continuos de los nervios periféricos son de uso común para el manejo del dolor. Sin embargo, la incidencia de desplazamiento o migración del catéter es dudosa, pudiendo ser infraestimada y no denunciarse. Nuestro objetivo fue evaluar el posicionamiento del extremo del catéter supraescapular antes y después de la manipulación rutinaria y simulada mediante fisioterapia de hombro en un modelo cadavérico anatómico.MétodoSe colocaron 8 catéteres para bloqueo continuo y ecoguiado del nervio supraescapular en cadáveres frescos criopreservados. La tomografía computarizada (TC) confirmó la localización de la punta del catéter tras la inyección de 1ml de medio de contraste. Realizamos una serie de movimientos estandarizados de hombro durante una sesión simulada de fisioterapia de hombro en cadáveres. Tras ello, administramos 1ml de azul de metileno a través de los catéteres, y seguidamente realizamos disecciones para identificar con precisión la localización de las puntas del catéter y compararlas con su localización previa a la «fisioterapia».ResultadosLa imagen de la TC confirmó la localización en todos los casos de los extremos del catéter en la muesca supraescapular. Sin embargo, tras la fisioterapia, se encontró que 2 catéteres (25%) habían migrado y, en especial, uno fue localizado en el músculo supraespinoso y el otro en el músculo trapecio.ConclusiónNuestros hallazgos sugieren que el desplazamiento del catéter puede producirse en cerca del 25% de los casos tras la manipulación mediante fisioterapia simulada. Sin embargo, es necesaria más investigación para determinar la incidencia real de los desplazamientos del catéter en la práctica clínica. (AU)

Background: Continuous peripheral nerve blocks are commonly used for pain management. However, the incidence of catheter dislodgement or migration is unclear, and may be underestimated and underreported. Our objective was to assess suprascapular catheter tip positioning before and after routine simulated shoulder physiotherapy manipulation in an anatomical cadaver model.MethodEight ultrasound-guided continuous suprascapular nerve block catheters were placed in cryopreserved fresh cadavers. Computed tomography (CT) confirmed the location of the catheter tip after injection of 1ml of contrast medium. We performed a series of standardized shoulder movements during a simulated shoulder physiotherapy session in cadavers. Following this, we administered 1ml of methylene blue through the catheters, and then performed anatomical dissections to accurately identify the location of the catheter tips and compare them to their placement prior to the ‘physiotherapy’ResultCT imaging confirmed the location of the catheter tips at the suprascapular notch in all cases. However, following physiotherapy, 2 catheters (25%) were found to have migrated - specifically, 1 was located in the supraspinatus muscle, and the other was located in the trapezius muscle.ConclusionOur findings suggest that catheter dislodgement may occur in approximately 25% of cases following simulated physiotherapy manipulation. However, further research is needed to determine the read incidence of catheter dislodgement in clinical practice. (AU)

Comparison of diffusion ranges at different local anesthetic volumes during superior laryngeal nerve block.

OBJECTIVES: Ultrasound-guided superior laryngeal nerve (SLN) block is a practical and painless approach to avoid the hemodynamic stress response during endotracheal intubation and relieve sore throat after laryngeal surgery. The main purpose of this study was to establish an optimal dosage of local anesthetic when performing SLN block to help anesthetists balance analgesia and side effects. METHODS: Twenty fresh larynx specimens were obtained immediately after resection and then injected with 2-, 3-, 4-, or 5- mL of a lidocaine-blue dye mixture at bilateral SLN puncture sites. Superficial areas of deposited blue dye were measured. Dye leakage and surrounding dyed tissue were recorded. Another 40 patients were included in the ultrasound investigation. Distances between the internal branch of the SLN (iSLN) and adjacent structures were calculated. RESULTS: The dye spread area was greater with the administration of larger doses, especially to the visceral space. A 2- or 3-mL injection of local anesthetic was sufficient to infiltrate the SLN gap. A higher incidence of dye leaking out of the thyrohyoid membrane and anterior epiglottis space was observed; furthermore, there was substantially more dyed hyoid/thyroid cartilage with 4 and 5 mL of injected dye mixture than 2 mL. There was no significant difference between the specimen and ultrasound measurements of for length of iSLN-adjacent structures. CONCLUSIONS: In the Chinese population, 2- or 3- mL of local anesthetic is a safe dose during SLN block. A larger volume could overflow from the cavity to cause complications. The thyrohyoid membrane combined with the superior laryngeal artery is a reliable target for positioning the iSLN during ultrasound-guided regional anesthesia.

[Old and New Regional Anesthesia Procedures Under Review - Abdomen to Toe]. / Alte und neue Regionalanästhesieverfahren unter Review ­ Bauch bis Fußzehe.

Ultrasound (US) technology has significantly expanded the spectrum of regional anesthesiological procedures in recent years. Abdominal wall blocks are becoming an increasingly integral part of a multimodal postoperative pain concept after abdominal surgery, gynecological or urological interventions. Thoracic epidural analgesia remains the gold standard for extensive surgery. The requirement for rapid postoperative mobilization and discharge after lower extremity surgery has led to the abandonment of neuroaxial or plexus blocks in favor of selective, peripheral blocks such as the PENG block or adductor canal block. The following article is intended to show the reader the change in the use of regional anesthesiological procedures for abdominal wall and lower extremity blocks using selected blockages.

[Common and New Regional Anaesthesia Techniques Under Review - From Head to Abdomen]. / Alte und neue Regionalanästhesieverfahren unter Review ­ Kopf bis Bauch.

By implementation of sonography regional anesthesia became more relevant in the daily practice of anesthesia and pain therapy. Due to visualized needle guidance ultrasound supports more safety during needle placement. Thereby new truncal blocks got enabled. Next to the blocking of specific nerve structures, plane blocks got established which can also be described as interfascial compartment blocks. The present review illustrates published and established blocks in daily practice concerning indications and the procedural issues. Moreover, the authors explain potential risks, complications and dosing of local anesthetics.

[Peripheral Regional Anesthesia Techniques - Standards in Flux?!] / Periphere Regionalanästhesieverfahren ­ Standards im Wandel?!

This review article provides an overview of current developments in peripheral regional anaesthesia (RA). The authors present a subjective compilation based on discussions at professional events and inquiries to the Working Group on Regional Anaesthesia of the German Society for Anaesthesiology and Intensive Care Medicine (DGAI). The article addresses several relevant topics, including the handling of antithrombotic medication in peripheral blockades with reference to European guidelines, the debate on the discharge timing after plexus anaesthesia, and the consideration of rebound pain as an independent pain entity following RA.Furthermore, the contentious discussion regarding the administration of peripheral nerve blockades under general anaesthesia is illuminated. The authors express no fundamental concerns in this regard but emphasize the importance of preoperative evaluation and individual patient needs. The question of mixing local anaesthetics is also addressed, with the authors critically questioning this tradition and recommending the use of individual, long-acting substances.Another focal point is the application of peripheral nerve blockades in emergency medicine, both in preclinical and emergency room settings. The authors highlight the necessity for high-quality studies and discuss the complex organizational issues associated with the preclinical application of RA techniques.

Análisis retrospectivo de la anestesia regional en la cirugía de cadera: Auditoría clínica / Retrospective analysis of regional anaesthesia in hip surgery: A clinical audit

Introducción: La artroplastia total de cadera es una de las intervenciones quirúrgicas más frecuentes en el contexto hospitalario. Sin embargo, sigue desconociéndose el método ideal para manejar el dolor postoperatorio. Las técnicas de analgesia multimodal basadas en la anestesia regional se encuentran entre las soluciones más prometedoras. Objetivos: El objetivo de este estudio fue evaluar el dolor postoperatorio tras la artroplastia total de cadera, de acuerdo con si se realizaron, o no, bloqueos del nervio periférico (bloqueo femoral, bloqueo de la fascia iliaca y bloqueo del grupo de nervios pericapsulares). Se midió el consumo de morfina intravenosa durante la estancia del paciente en la unidad de cuidados posanestésicos, así como el número de rescates con opioides transcurridas 24 y 48 h de la intervención. Como objetivos secundarios, se establecieron la prevalencia de la lesión nerviosa, la prolongación del bloqueo cuadricipital y el consumo de morfina, de acuerdo con otras variables de interés. Materiales y métodos: En este estudio retrospectivo observacional, se recopilaron datos de la historia clínica digital de 656 pacientes de cirugía traumatológica de abril de 2018 a agosto de 2020, con los criterios de inclusión siguientes: mayores de 18 años, ASA I-III, artroplastia total de cadera primaria con anestesia general o anestesia subaracnoidea (solo con bupivacaína hiperbárica) y uso de levobupivacaína para el bloqueo del nervio periférico. Resultados: Se seleccionó un total de 362 pacientes. La indicación quirúrgica principal fue coxartrosis (61,3%), seguida de fractura de cadera (22,6%). Se realizaron bloqueos del nervio periférico en 169 pacientes (66,3% femoral, 27,7% PENG, y 6% de fascia ilíaca). El consumo medio postoperatorio de opioides en la UCPA fue inferior en los pacientes que recibieron bloqueo PENG (2,2 mg) o femoral (3,27 mg), en comparación con los que no recibieron ninguno de los dos (6,69 mg)...(AU)

Introduction: Total hip arthroplasty is one of the most frequent surgical interventions in the hospital setting. Nonetheless, the ideal method to manage post-operative pain is still unknown. Multimodal analgesia techniques based on regional anaesthesia are amongst the most promising solutions. Objectives: The aim of this study was to evaluate postoperative pain after total hip arthroplasty according to whether peripheral nerve block was performed (femoral block, fascia iliaca block and pericapsular nerve group block). Intravenous morphine consumption during the patient's stay in the post-anaesthesia care unit was measured, as well as the number of opioid rescues at 24 and 48h post intervention. As secondary objectives, the prevalence of nerve injury, prolonged quadricipital block, and morphine consumption were established according to other variables of interest. Materials and methods: In this observational retrospective study, data was collected from the electronic medical record of 656 traumatological surgery patients from April 2018 to August 2020, with the following inclusion criteria: over 18 years old, ASA I-III, primary total hip arthroplasty under general anaesthesia or subarachnoid anaesthesia (only with hyperbaric bupivacaine) and use of levobupivacaine for peripheral nerve block. Results: A total of 362 patients were selected. The main surgical indication was coxarthrosis (61.3%), followed by hip fracture (22.6%). Peripheral nerve blocks were performed on 169 patients (66.3% femoral, 27.7% PENG, and 6.0% fascia iliaca). Mean postoperative opioid consumption in PACU was lower in patients in who received a PENG (2.2 mg) or a femoral (3.27 mg) block, compared to those who received neither (6.69 mg). There were no differences in opioid rescues at 24 and 48h after the procedure...(AU)

Tratamiento de la pseudoartrosis de radio con injerto de cresta iliaca y células madre del aspirado de médula ósea. A propósito de un caso / Treatment of radial pseudarthrosis with iliac crest graft and bone marrow aspirate stem cells. A case report

La pseudoartrosis es una complicación caracterizada por la ausencia de consolidación del hueso a los 9 meses desde el inicio de la fractura, con falta de progresión radiológica los últimos 3 meses, siendo sus principales causas el exceso de movimiento en el foco de fractura y una insuficiente vascularización. A pesar de no tratarse de una complicación frecuente, los huesos del antebrazo ocupan el 4.º puesto en incidencia de presentación. El manejo anestésico de la patología quirúrgica del miembro superior se realiza generalmente en régimen ambulatorio con técnicas de anestesia regional guiadas por ecografía. Estas técnicas tienen una doble función: anestesia durante el propio acto quirúrgico con una mínima variabilidad sobre el estado basal del paciente y analgesia en el postoperatorio inmediato, permitiendo de esta manera el alta a domicilio de forma más segura y precoz. Presentamos el caso de un varón de 34 años, con desarrollo de pseudoartrosis atrófica tras fractura diafisaria de radio, en el que se realiza injerto óseo de cresta ilíaca y aspirado de células madre como estímulo de la osteogénesis.(AU)

Pseudarthrosis is a complication characterised by the absence of bone healing 9 months after the onset of the fracture, with a lack of radiological progressionin the last 3 months, and its main causes are excessive movement at the fracture site and insufficient vascularisation. Despite not being a frequent complica-tion, the bones of the forearm occupy the fourth place in incidence of presentation. The anaesthetic management of surgical pathology of the upper limb isgenerally performed on an outpatient basis with regional anaesthesia techniques guided by ultrasound. These techniques have a dual function: anaesthesiaduring the surgical act with minimal variability over the patient’s baseline condition and analgesia in the immediate postoperative period, thus allowing forsafer and earlier discharge home. We present the case of a 34-year-old male with diagnosis of atrophic pseudarthrosis following a diaphyseal fracture of theradius, in whom iliac crest bone grafting and stem cell aspiration were performed to stimulate osteogenesis.(AU)

Regional anaesthesia education for consultants and specialists in the UK: a mixed-methods analysis.

BACKGROUND: Regional anaesthesia plays an important role in perioperative care, but gaps in proficiency persist among consultants and specialists. This study aimed to assess confidence levels in performing Plan A blocks among this cohort and to examine the barriers and facilitators influencing regional anaesthesia education. METHODS: Utilising a mixed-methods design, we performed a quantitative survey to gauge self-reported confidence in performing Plan A blocks, coupled with qualitative interviews to explore the complexities of educational barriers and facilitators. UK consultant and specialist anaesthetists were included in the study. RESULTS: A total of 369 survey responses were analysed. Only 22% of survey respondents expressed confidence in performing all Plan A blocks. Specialists (odds ratio [OR] 0.391, 95% confidence interval [CI] 0.179-0.855, P=0.016) and those in their roles for >10 yr (OR 0.551, 95% CI 0.327-0.927, P = 0.024) reported lower confidence levels. A purposive sample was selected for interviews, and data saturation was reached at 31 interviews. Peer-led learning emerged as the most effective learning modality for consultants and specialists. Barriers to regional anaesthesia education included apprehensions regarding complications, self-perceived incompetence, lack of continuing professional development time, insufficient support from the multidisciplinary team, and a lack of inclusivity within the regional anaesthesia community. Organisational culture had a substantial impact, with the presence of local regional anaesthesia champions emerging as a key facilitator. CONCLUSIONS: This study highlights persistent perceived deficiencies in regional anaesthesia skills among consultants and specialists. We identified multiple barriers and facilitators, providing insights for targeted interventions aimed at improving regional anaesthesia education in this group.

Artificial intelligence for ultrasound scanning in regional anaesthesia: a scoping review of the evidence from multiple disciplines.

BACKGROUND: Artificial intelligence (AI) for ultrasound scanning in regional anaesthesia is a rapidly developing interdisciplinary field. There is a risk that work could be undertaken in parallel by different elements of the community but with a lack of knowledge transfer between disciplines, leading to repetition and diverging methodologies. This scoping review aimed to identify and map the available literature on the accuracy and utility of AI systems for ultrasound scanning in regional anaesthesia. METHODS: A literature search was conducted using Medline, Embase, CINAHL, IEEE Xplore, and ACM Digital Library. Clinical trial registries, a registry of doctoral theses, regulatory authority databases, and websites of learned societies in the field were searched. Online commercial sources were also reviewed. RESULTS: In total, 13,014 sources were identified; 116 were included for full-text review. A marked change in AI techniques was noted in 2016-17, from which point on the predominant technique used was deep learning. Methods of evaluating accuracy are variable, meaning it is impossible to compare the performance of one model with another. Evaluations of utility are more comparable, but predominantly gained from the simulation setting with limited clinical data on efficacy or safety. Study methodology and reporting lack standardisation. CONCLUSIONS: There is a lack of structure to the evaluation of accuracy and utility of AI for ultrasound scanning in regional anaesthesia, which hinders rigorous appraisal and clinical uptake. A framework for consistent evaluation is needed to inform model evaluation, allow comparison between approaches/models, and facilitate appropriate clinical adoption.

Celebrating the state of the art and innovations in regional anaesthesia in the British Journal of Anaesthesia.

To coincide with the annual scientific meeting of Regional Anaesthesia UK in London 2024, where there is a joint scientific session with the British Journal of Anaesthesia, a special regional anaesthesia edition of the journal has been produced. This editorial offers some highlights from the manuscripts contained within the special edition.

Research priorities in regional anaesthesia: an international Delphi study.

BACKGROUND: Regional anaesthesia use is growing worldwide, and there is an increasing emphasis on research in regional anaesthesia to improve patient outcomes. However, priorities for future study remain unclear. We therefore conducted an international research prioritisation exercise, setting the agenda for future investigators and funding bodies. METHODS: We invited members of specialist regional anaesthesia societies from six continents to propose research questions that they felt were unanswered. These were consolidated into representative indicative questions, and a literature review was undertaken to determine if any indicative questions were already answered by published work. Unanswered indicative questions entered a three-round modified Delphi process, whereby 29 experts in regional anaesthesia (representing all participating specialist societies) rated each indicative question for inclusion on a final high priority shortlist. If ≥75% of participants rated an indicative question as 'definitely' include in any round, it was accepted. Indicative questions rated as 'definitely' or 'probably' by <50% of participants in any round were excluded. Retained indicative questions were further ranked based on the rating score in the final Delphi round. The final research priorities were ratified by the Delphi expert group. RESULTS: There were 1318 responses from 516 people in the initial survey, from which 71 indicative questions were formed, of which 68 entered the modified Delphi process. Eleven 'highest priority' research questions were short listed, covering themes of pain management; training and assessment; clinical practice and efficacy; technology and equipment. CONCLUSIONS: We prioritised unanswered research questions in regional anaesthesia. These will inform a coordinated global research strategy for regional anaesthesia and direct investigators to address high-priority areas.