Single, double or multiple‐injection techniques for non‐ultrasound guided axillary brachial plexus block in adults undergoing surgery of the lower arm

Antecedentes La anestesia regional que comprende el bloqueo axilar del plexo braquial es una técnica anestésica común para la cirugía del miembro superior distal. Esta es una actualización de una revisión publicada por primera vez en 2006 y actualizada previamente en 2011 y 2013. Objetivos Comparar los efectos relativos (beneficiosos y perjudiciales) de tres técnicas de inyección (simple, doble y múltiple) para el bloqueo axilar del plexo braquial en la cirugía de la extremidad superior distal. Se consideran estos efectos principalmente en términos de la efectividad del anestésico; la tasa de complicaciones (neurológicas y vasculares); y el dolor y las molestias causadas por la realización del bloqueo. Métodos de búsqueda Se realizaron búsquedas en el Registro Cochrane Central de Ensayos Controlados (Cochrane Central Register of Controlled Trials, CENTRAL; 2016, número 3), MEDLINE (1946 hasta la primera semana de abril 2016), Embase (1947 hasta el 18 de abril 2016) y en las listas de referencias de los ensayos. Se estableció contacto con los autores de los ensayos. La fecha de la última búsqueda fue abril 2016 (actualizada desde marzo 2013). Criterios de selección Se incluyeron ensayos controlados aleatorizados que comparaban técnicas de inyección doble con las de inyección única, técnicas de inyección múltiple con las de inyección única, o técnicas de inyección múltiple con las de inyección doble para el bloqueo axilar en adultos sometidos a una cirugía del miembro superior distal. Se excluyeron los ensayos que utilizaron técnicas guiadas por ecografía. Obtención y análisis de los datos La selección de los estudios, la evaluación del «riesgo de sesgo» y la extracción de datos fueron realizadas de forma independiente por al menos dos investigadores. Se realizó un metanálisis. Resultados principales Se incluyó un ensayo nuevo con 45 participantes en esta revisión actualizada. En total se incluyeron 22 ensayos con un total de 2193 participantes que recibieron anestesia regional para la cirugía de mano, muñeca, antebrazo o codo. La evaluación del «riesgo de sesgo» indicó que el diseño y la realización de los ensayos generalmente fueron adecuados; las áreas de debilidad más comunes fueron el cegamiento y la ocultación de la asignación. Nueve ensayos que compararon inyecciones dobles versus simples mostraron una disminución estadísticamente significativa del fracaso de la anestesia primaria (riesgo relativo [RR] 0,55; intervalo de confianza [IC] del 95%: 0,34 a 0,89; evidencia de calidad alta). El análisis de subgrupos por método de localización del nervio mostró que el tamaño del efecto fuer mayor al utilizar la neuroestimulación en lugar de la técnica transarterial. Nueve ensayos que compararon las inyecciones múltiples con las simples mostraron una disminución estadísticamente significativa del fracaso de la anestesia primaria (RR 0,25; IC del 95%: 0,14 a 0,42; evidencia de calidad alta). Los datos agrupados de cinco ensayos también mostraron una disminución significativa del bloqueo motor incompleto (RR 0,61; IC del 95%: 0,39 a 0,96; evidencia de calidad alta) en el grupo de inyecciones múltiples. Doce ensayos que compararon inyecciones múltiples versus dobles mostraron una disminución estadísticamente significativa del fracaso de la anestesia primaria (RR 0,27; IC del 95%: 0,19 a 0,39; evidencia de calidad alta). Los datos agrupados de seis ensayos también mostraron una disminución significativa del bloqueo motor incompleto (RR 0,55; IC del 95%: 0,36 a 0,85; evidencia de calidad alta) en el grupo de inyecciones múltiples. El dolor por el torniquete se redujo de manera significativa con las inyecciones múltiples en comparación con las inyecciones dobles (RR 0,53; IC del 95%: 0,33 a 0,84; evidencia de calidad alta). Por lo demás, no hubo diferencias estadísticamente significativas entre los grupos en ninguna de las tres comparaciones sobre el fracaso de la analgesia secundaria, las complicaciones y las molestias de los pacientes. En comparación con las inyecciones múltiples, el tiempo de realización del bloqueo fue significativamente más corto en el caso de la inyección única (DM 3,33 minutos, IC del 95%: 2,76 a 3,90) y las inyecciones dobles (DM 1,54 minutos, IC del 95%: 0,80 a 2,29); sin embargo, no hubo diferencias en el tiempo de preparación para la cirugía. Conclusiones de los autores Esta revisión aporta evidencia de que las técnicas de inyección múltiple que utilizan la estimulación nerviosa para el bloqueo del plexo axilar producen una anestesia más efectiva que las técnicas de inyección doble o simple. Sin embargo, no hubo evidencia suficiente para establecer conclusiones definitivas sobre las diferencias en otros resultados, incluida la seguridad.Q1Q1Revisión1-96Background Regional anaesthesia comprising axillary block of the brachial plexus is a common anaesthetic technique for distal upper limb surgery. This is an update of a review first published in 2006 and previously updated in 2011 and 2013. Objectives To compare the relative effects (benefits and harms) of three injection techniques (single, double and multiple) of axillary block of the brachial plexus for distal upper extremity surgery. We considered these effects primarily in terms of anaesthetic effectiveness; the complication rate (neurological and vascular); and pain and discomfort caused by performance of the block. Search methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 3), MEDLINE (1946 to April Week 1 2016), Embase (1947 to April 18 2016) and reference lists of trials. We contacted trial authors. The date of the last search was April 2016 (updated from March 2013). Selection criteria We included randomized controlled trials that compared double with single‐injection techniques, multiple with single‐injection techniques, or multiple with double‐injection techniques for axillary block in adults undergoing surgery of the distal upper limb. We excluded trials using ultrasound‐guided techniques. Data collection and analysis Independent study selection, 'Risk of bias' assessment and data extraction were performed by at least two investigators. We undertook meta‐analysis. Main results We included one new trial involving 45 participants in this updated review. In total we included 22 trials involving a total of 2193 participants who received regional anaesthesia for hand, wrist, forearm or elbow surgery. 'Risk of bias' assessment indicated that trial design and conduct were generally adequate; the most common areas of weakness were in blinding and allocation concealment. Nine trials comparing double versus single injections showed a statistically significant decrease in primary anaesthesia failure (risk ratio (RR) 0.55, 95% confidence interval (CI) 0.34 to 0.89, high‐quality evidence). Subgroup analysis by method of nerve location showed that the effect size was greater when neurostimulation was used rather than the transarterial technique. Nine trials comparing multiple with single injections showed a statistically significant decrease in primary anaesthesia failure (RR 0.25, 95% CI 0.14 to 0.42, high‐quality evidence). Pooled data from five trials also showed a significant decrease in incomplete motor block (RR 0.61, 95% CI 0.39 to 0.96, high‐quality evidence) in the multiple‐injection group. Twelve trials comparing multiple versus double injections showed a statistically significant decrease in primary anaesthesia failure (RR 0.27, 95% CI 0.19 to 0.39, high‐quality evidence). Pooled data from six trials also showed a significant decrease in incomplete motor block (RR 0.55, 95% CI 0.36 to 0.85, high‐quality evidence) in the multiple injection group. Tourniquet pain was significantly reduced with multiple injections compared with double injections (RR 0.53, 95% CI 0.33 to 0.84, high‐quality evidence). Otherwise there were no statistically significant differences between groups in any of the three comparisons on secondary analgesia failure, complications and patient discomfort. Compared with multiple injections, the time for block performance was significantly shorter for single injection (MD 3.33 minutes, 95% CI 2.76 to 3.90) and double injections (MD 1.54 minutes, 95% CI 0.80 to 2.29); however there was no difference in time to readiness for surgery. Authors' conclusions This review provides evidence that multiple‐injection techniques using nerve stimulation for axillary plexus block produce more effective anaesthesia than either double or single‐injection techniques. However, there was insufficient evidence to draw any definitive conclusions regarding differences in other outcomes, including safety

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

Ultrasound guided distal peripheral nerve block of the upper limb: A technical review

Upper extremity surgery is commonly performed under regional anesthesia. The advent of ultrasonography has made performing upper extremity nerve blocks relatively easy with a high degree of reliability. The proximal approaches to brachial plexus block such as supraclavicular plexus block, infraclavicular plexus block, or the axillary block are favored for the most surgical procedures of distal upper extremity. Ultrasound guidance has however made distal nerve blocks of the upper limb a technically feasible, safe and efficacious option. In recent years, there has thus been a resurgence of distal peripheral nerve blocks to facilitate hand and wrist surgery. In this article, we review the technical aspects of performing the distal blocks of the upper extremity and highlight some of the clinical aspects of their usage

Erector spinae plane block for postoperative analgesia in pediatric oncological thoracic surgery

Q1880-88

Mechanisms of action of fascial plane blocks: A narrative review

Background Fascial plane blocks (FPBs) target the space between two fasciae, rather than discrete peripheral nerves. Despite their popularity, their mechanisms of action remain controversial, particularly for erector spinae plane and quadratus lumborum blocks. Objectives This narrative review describes the scientific evidence underpinning proposed mechanisms of action, highlights existing knowledge gaps, and discusses implications for clinical practice and research. Findings There are currently two plausible mechanisms of analgesia. The first is a local effect on nociceptors and neurons within the plane itself or within adjacent muscle and tissue compartments. Dispersion of local anesthetic occurs through bulk flow and diffusion, and the resulting conduction block is dictated by the mass of local anesthetic reaching these targets. The extent of spread, analgesia, and cutaneous sensory loss is variable and imperfectly correlated. Explanations include anatomical variation, factors governing fluid dispersion, and local anesthetic pharmacodynamics. The second is vascular absorption of local anesthetic and a systemic analgesic effect at distant sites. Direct evidence is presently lacking but preliminary data indicate that FPBs can produce transient elevations in plasma concentrations similar to intravenous lidocaine infusion. The relative contributions of these local and systemic effects remain uncertain. Conclusion Our current understanding of FPB mechanisms supports their demonstrated analgesic efficacy, but also highlights the unpredictability and variability that result from myriad factors at play. Potential strategies to improve efficacy include accurate deposition close to targets of interest, injections of sufficient volume to encourage physical spread by bulk flow, and manipulation of concentration to promote diffusion