[Influence of femoral catheter stimulation intensity on post-surgical analgesia after total knee replacement]. / Influencia de la intensidad de estimulación del catéter femoral sobre analgesia postoperatoria tras prótesis de rodilla.

INTRODUCTION: Stimulating catheters allow the catheter point to be positioned near the nerve, thus reducing the amount of local anaesthetic required for a successful block. There is currently a debate on what is the stimulation intensity required to provide adequate analgesia, although it does seem that if it is obtained with 1mAmp or less the block is more effective. The objective of the study was to demonstrate whether different neurostimulation intensities with the stimulating catheter at femoral nerve level, had an influence on the adequacy of post-surgical analgesia during the 48h after total knee arthroplasty. MATERIAL AND METHODS: A comparative, prospective and randomised study was conducted on patients subjected to total knee replacement. After surgery with subarachnoid anaesthesia, a continuous femoral block was performed with a stimulating catheter at a neurostimulation intensity 0.2 and 0.5mAmp in Group 1, between 0.6 and 1mAmp in Group 2, equal or higher than 1.1mAmp in Group 3, and in Group 4 the catheter was introduced between 3-5cm without looking for a motor response. A dose of 0.2% ropivacaine 0.4mL/kg and an infusion at 5mL/h, with boluses of 10mL/30min, was administered via the catheter. Sciatic nerve block was also performed on all patients with 20ml of 0.5% ropivacaine. The patient demographics were recorded, as well as, post-surgical analgesia details, sensory and motor block in each area, boluses requested, rescue analgesia, and undesirable effects at 8, 16, 24, 36 and 48h. RESULTS: A total of 124 patients were included, 32 in Group 1 (25.8%), 21 in Group 2 (16.9%), 31 in Group 3 (25%), and 40 in group 4 (32.3%). The 4 groups were homogeneous as regards age, height, weight and ASA. There were no statistically significant differences found in the post-operative pain, except during movement in the femoral area at 36 hours (p=.032). There were also no statistically significant differences found in the sensory block in the femoral area at 48 hours (p=.019) and in the femoral cutaneous nerve block at 8 hours (p=.049) or at 24 hours (p=.045). As regards motor block, differences were only found in the obturator nerve at 24 hours (p=.016). There were no differences in rescue analgesia, patient controlled analgesia (PCA) boluses requested or administered, except that the number of boluses requested at 16 hours was less in Group 3 (p=.049). There were also no significant differences in undesirable effects or in the level of satisfaction of the patients between the four groups. CONCLUSIONS: In our study, no influence was found on the level of analgesia provided after knee replacement surgery with the neurostimulation intensity to which the neuromuscular system involved responded when a stimulating catheter is inserted at femoral level.

Influencia de la intensidad de estimulación del catéter femoral sobre analgesia postoperatoria tras prótesis de rodilla / Influence of femoral catheter stimulation intensity on post-surgical analgesia after total knee replacement

Introducción. Nuestro objetivo fue comprobar si distintas intensidades de neuroestimulación con el catéter estimulador a nivel del nervio femoral, influyen en la adecuación de la analgesia postoperatoria durante las primeras 48h del postoperatorio tras prótesis total de rodilla. Los catéteres estimuladores permiten posicionar la punta del catéter en la proximidad del nervio y, por tanto, reducir la cantidad de anestésico local necesaria para un bloqueo con éxito. En la actualidad, está debatida cuál es la intensidad de estimulación a la que se deben colocar para proporcionar analgesia adecuada, aunque parece ser que si se obtiene con 1mAmp o menos, el bloqueo es más efectivo. Material y métodos. Estudio comparativo, prospectivo y aleatorizado en pacientes intervenidos de prótesis total de rodilla. Tras la cirugía con anestesia subaracnoidea, se realizó un bloqueo femoral continuo con un catéter estimulador a una intensidad de neuroestimulación de entre 0,2 y 0,5mAmp en el grupo 1, entre 0,6 y 1mAmp en el grupo 2, igual o superior a 1,1mAmp en el grupo 3, y en el grupo 4 se introdujo el catéter entre 3-5cm sin buscar respuesta motora. Se administró a través del catéter ropivacaína 0,2% 0,4mL/kg y perfusión a 5mL/h, con bolos de 10mL/30min. En todos los pacientes se efectuó también un bloqueo del nervio ciático con 20ml de ropivacaína 0,5%. Se registraron los datos demográficos de los pacientes, características de la analgesia postoperatoria, bloqueo sensitivo y motor en cada territorio, bolos solicitados y administrados, analgesia de rescate y efectos indeseables a las 8, 16, 24, 36 y 48h. Resultados. Se incluyó a 124 pacientes, 32 en grupo 1 (25,8%), 21 en grupo 2 (16,9%), 31 en grupo 3 (25%) y 40 en grupo 4 (32,3%). Los 4 grupos fueron homogéneos respecto a edad, talla, peso y ASA. En el dolor postoperatorio no se encontraron diferencias estadísticamente significativas, excepto durante el movimiento a las 36h en el territorio femoral (p=0,032). También se encontraron diferencias estadísticamente significativas en el bloqueo sensitivo en territorio femoral a las 48h (p=0,019) y en el femorocutáneo a las 8 (p=0,049) y a las 24h (p=0,045). Con relación al bloqueo motor, tan solo se encontraron diferencias en el nervio obturador a las 24h (p=0,016). No hubo diferencias en la analgesia de rescate, bolos PCA solicitados y administrados, excepto en el número de bolos solicitados a las 16h, que fueron menores en el grupo 3 (p= 0,049). Tampoco hubo diferencias significativas en los efectos indeseables ni en el grado de satisfacción de los pacientes entre los 4 grupos. Conclusiones. En nuestro estudio, no se ha encontrado influencia de la intensidad de neuroestimulación a la que responde el sistema neuromuscular implicado cuando se coloca un catéter estimulador a nivel femoral sobre la analgesia que proporciona tras la cirugía protésica de rodilla(AU)

Introduction. Stimulating catheters allow the catheter point to be positioned near the nerve, thus reducing the amount of local anaesthetic required for a successful block. There is currently a debate on what is the stimulation intensity required to provide adequate analgesia, although it does seem that if it is obtained with 1mAmp or less the block is more effective. The objective of the study was to demonstrate whether different neurostimulation intensities with the stimulating catheter at femoral nerve level, had an influence on the adequacy of post-surgical analgesia during the 48h after total knee arthroplasty. Material and methods. A comparative, prospective and randomised study was conducted on patients subjected to total knee replacement. After surgery with subarachnoid anaesthesia, a continuous femoral block was performed with a stimulating catheter at a neurostimulation intensity 0.2 and 0.5mAmp in Group 1, between 0.6 and 1mAmp in Group 2, equal or higher than 1.1mAmp in Group 3, and in Group 4 the catheter was introduced between 3-5cm without looking for a motor response. A dose of 0.2% ropivacaine 0.4mL/kg and an infusion at 5mL/h, with boluses of 10mL/30min, was administered via the catheter. Sciatic nerve block was also performed on all patients with 20ml of 0.5% ropivacaine. The patient demographics were recorded, as well as, post-surgical analgesia details, sensory and motor block in each area, boluses requested, rescue analgesia, and undesirable effects at 8, 16, 24, 36 and 48h. Results. A total of 124 patients were included, 32 in Group 1 (25.8%), 21 in Group 2 (16.9%), 31 in Group 3 (25%), and 40 in group 4 (32.3%). The 4 groups were homogeneous as regards age, height, weight and ASA. There were no statistically significant differences found in the post-operative pain, except during movement in the femoral area at 36hours (p=.032). There were also no statistically significant differences found in the sensory block in the femoral area at 48hours (p=.019) and in the femoral cutaneous nerve block at 8hours (p=.049) or at 24hours (p=.045). As regards motor block, differences were only found in the obturator nerve at 24hours (p=.016). There were no differences in rescue analgesia, patient controlled analgesia (PCA) boluses requested or administered, except that the number of boluses requested at 16hours was less in Group 3 (p=.049). There were also no significant differences in undesirable effects or in the level of satisfaction of the patients between the four groups. Conclusions. In our study, no influence was found on the level of analgesia provided after knee replacement surgery with the neurostimulation intensity to which the neuromuscular system involved responded when a stimulating catheter is inserted at femoral level(AU)

[Neurologic complications of central neuraxial blocks]. / Complicaciones neurológicas en los bloqueos centrales.

Central neuraxial blocks, which are associated with a low incidence of complications, are safe. When complications do occur, however, the resulting morbidity and mortality is considerable. The reported incidence of complications in all series is under 4 per 10000 patients, but given the absence of formal registries and notification procedures, which have legal implications, the real rate of occurrence of these rare events is uncertain. We searched the literature through PubMed and the Cochrane Plus Library for a 5-year period, using the search terms epidural anesthesia AND safety, spinal anesthesia AND safety, complications AND epidural anesthesia, complications AND spinal anesthesia, neurologic complications AND epidural anesthesia, and neurologic complications AND spinal anesthesia. Neuraxial injury after a central blockade may be the result of anatomical and/or physiological lesions affecting the spinal cord, spinal nerves, nerve roots, or blood supply. The pathophysiology of neuraxial injury may be related to mechanical, ischemic, or neurotoxic damage or any combination. When a complication occurs, factors related to the technique will have interacted with pre-existing patient-related conditions. Various scientific societies have published guidelines for managing the complications of regional anesthesia. Recently published clinical practice guidelines recommend ultrasound imaging as a useful tool in performing a central neuraxial block.

Estudio comparativo de la eficacia del bloqueo supraclavicular en la artroscopia de hombro / Comparative study of the efficacy of the supraclavicular block for arthroscopic shoulder surgery

Introducción. Nuestro objetivo es valorar la eficacia de dos técnicas anestésicas en el tratamiento del dolor postoperatorio, así como su influencia en la estancia hospitalaria, tras la cirugía artroscópica de hombro. Material y métodos. Estudio retrospectivo basado en la recogida de datos de las historias de anestesiología y de nuestra unidad de dolor agudo (UDA), durante un período de 6 meses, seleccionando los casos de artroscopias de hombro realizadas y distribuyendo los pacientes en 2 grupos en función de la técnica anestésica empleada. En el grupo i se incluyó a pacientes con anestesia locorregional (bloque interescalénico e interesternocleidomastoideo) combinado con anestesia general. En el grupo ii se incluyeron los casos de anestesia general con analgesia por vía intravenosa con bolos de fentanilo. Material y métodos. Las variables registradas fueron: dolor posoperatorio, tanto en reposo como en movimiento, en las primeras 24h, utilizando una escala verbal simple (EVS), la presencia de efectos secundarios, la necesidad de rescate analgésico y el tiempo quirúrgico empleado. Material y métodos. En los casos en que los pacientes fueron dados de alta en las primeras 24h, se realizó una consulta telefónica para valoración de dichas variables. Material y métodos. El análisis estadístico se realizó mediante prueba de la t de Student (para variables numéricas) y prueba de la X2 (para analizar las relaciones entre variables cualitativas), considerando el estudio estadísticamente significativo si se obtuvo una p<0,05. Resultados. Se incluyó a un total de 26 pacientes (14 casos en el grupo i y 12 casos en el grupo ii). El análisis del dolor posoperatorio en las primeras 24h reveló que la EVS en reposo del grupo i fue de 1 para el percentil 75, mientras que en el grupo ii fue de 2. El dolor en movimiento obtuvo una EVS de 2,25 para el grupo i y de 3 para el grupo ii (p<0,05). Resultados. La necesidad de rescate se dio en un 1 (0,07%) caso en el primer grupo frente a 5 casos (0,41%) en el segundo grupo (p<0,05). Resultados. El análisis de las náuseas y los vómitos postoperatorios puso de manifiesto que en el grupo de la anestesia combinada no se presentó en ningún caso, mientras que en el grupo de la anestesia general se observó en 4 (0,33%) (p<0,05). Resultados. El tiempo quirúrgico estimado para el primer grupo fue de 125min de media, frente 116min del grupo ii (p>0,05). Resultados. En el grupo de la anestesia combinada el tiempo medio de estancia fue de 36h, frente a las 60h de media en el grupo de anestesia general (p<0,05). Conclusiones. El bloqueo del plexo braquial por encima de la clavícula combinado con anestesia general ha mostrado mayor eficacia en el control del dolor perioperatorio, tanto en reposo como con el movimiento, que la anestesia general con analgesia por vía intravenosa. Además, la incidencia de efectos indeseables, la necesidad de rescate y el tiempo de ingreso hospitalario fueron menores sido menor en el grupo de pacientes intervenidos con la técnica combinada, sin repercusión significativa en el tiempo de ocupación del quirófano (AU)

Objectives. Our aim is to evaluate the efficacy of two anesthetic techniques for the treatment of the postoperative pain, as well as their influence on hospital stay, after surgery arthroscopic of shoulder. Materials and methods. Retrospective study based on the collection of data from anesthesia histories and from of our postoperative acute pain unit, during a 6-months period. Cases of shoulder arthroscopies carried out during this period were selected and the patients were distributed in 2 groups depending on the anesthetic technique used: group I consisted of patients treated with locoregional anesthesia (interscalene and inter-sternocleidomastoid block) combined with general anesthesia. Group II was general anesthesia cases with intravenous analgesia. Materials and methods. The recorded variables were the following: postoperative pain, both at rest and during exercise in the first 24h, using a simple verbal scale (SVS); the presence of side effects, need of analgesic rescue and duration of hospital stay. Materials and methods. In the cases where the patients were discharged from hospital in the first 24h, a telephone consultation was carried out for the evaluation of the abovementioned variables. Materials and methods. Statistical analysis: Student-t and Chi-square tests. A P<.05 was considered statistically significant. Results. A total of 26 patients were included (14 cases in group I and 12 cases in group II). The analysis of the postoperative pain at rest in the first 24h revealed that the SVS in group I was 1 for the percentile 75, whereas in group II it was 2. The pain on movement was 2.25 for group I, and 3 for group II, (P<.05). Results. There was only 1 case with need of rescue (7%) in the first group, compared to the 5 cases (41%) in the second group (P<.05). Results. There were no cases of postoperative nausea and vomiting in the combined anesthesia group, whereas in the group with general anesthesia there were 4 cases (33%), (P<.05). Results. The estimated surgical time for the first group was 125min, compared to the estimated 116min for group II (p>.05). Results. In the group of combined anesthesia the average duration of hospital stay was 36h, compared to the 60h average duration in the group of General Anesthesia. (P<.05). Discussion. The blockade of the brachial plexus over the clavicle combined with general anesthesia has shown greater efficacy in the control of perioperative pain, both at rest and during exercise than the general anesthesia with intravenous analgesia. In addition, the incidence of undesirable effects, the need of rescue and the duration of hospital stay were lower in the group of patients with the combined technique, without significant effects on the duration of operating room occupation (AU)

Estudio comparativo entre la ecografía y la neuroestimulación en el aprendizaje del bloqueo ciático poplíteo posterior / No disponible

Introducción: La anestesia regional guiada mediante ecografía es un campo en rápido crecimiento y su docencia está siendo objeto de estudio. Este trabajo compara la realización del bloqueociático-poplíteo posterior mediante ecografía (ECO) o neuroestimulación (NE) por médicos especialistas en formación. Material y método: Se realizó un estudio prospectivo aleatorizado, con los pacientes distribuidos en dos grupos: el grupo ECO mediante técnica guiada con ecografía; el grupo NE empleó referencias de anatomía de superficie más neuroestimulación, considerando válida una respuesta muscular entre 0.2-0.5 mA. Las variables registradas fueron: tiempo de ejecución, número de intentos, número de punciones vasculares y de parestesias, así como éxito del bloqueo. Las técnicas fueron realizadas por un único especialista en formación, sin experiencia previa en anestesia regional ni ecografía, bajo la supervisión de un anestesiólogo experto. Resultados: Se obtuvieron 19 casos (ECO: 10; NE: 9). El grupo ECO requirió menos tiempo que el NE (108,5-338,6 sg, IC95%; p < 0,005) y menor número de intentos, 1,6 ± 0,7 para ECO, frente 9,5 ± 3,8 para NE (media ± ds; p < 0,05), obteniendo éxito en primera punción en un 80% para ECO frente a al11,1% para NE (p < 0,05). El grupo ECO asoció una menor incidencia de punciones vasculares y de parestesias. La tasa de éxito de la técnica fue del 100% en el grupo ECO, frente al 67,7% en NE. Conclusiones: Estos resultados sugieren que el empleo de ecografía en el aprendizaje del bloqueo poplíteo posterior por especialistas en formación, pudiera facilitar la ejecución de la técnica, asociar menor morbilidad y proporcionar mayor éxito del bloqueo nervioso periférico (AU)

Background: The ultrasound-guided regional anesthesia is a rapidly growing field and its teaching is being studied. This paper compares the performance of the posterior popliteal sciatic blockadeby ultrasound (ECO) with that of neurostimulation (NS) carried out by specialist doctors in training. Material and method: A prospective randomized trial was conducted with patients divided into two groups: group ECO treated with ultrasound-guided technique, and group NE in which surface anatomy and neurostimulation references were used, considering valid a muscle response between 0.2 and 0.5 mA. The variables recorded were run time, number of attempts, number of vascular punctures and paresthesias, and success of the blockade. The techniques were performed by a single training specialist without prior experience in regional anesthesia and ultrasound, under the supervision of an expert anaesthesiologist. Results: 19 cases were obteined (ECO: 10, NE 9), the ECO required less time than NE (108,5-338,6 sg, 95%, p < 0.005)and fewer attempts, 1.6 ± 0.7 for ECO, versus 9.5 ± 3.8 for NE(mean ± sd, p < 0.05), and success was achieved on first puncture on 80% of attempts in ECO group, versus 11.1% in NE group (p< 0.05). The ECO group associated a lower incidence of vascular puncture and paresthesia. The success rate of the technique was 100% in the ECO group, versus 67,7% in NE group. Conclusions: These results suggest that the use of ultrasound in the posterior popliteal block learning by training specialists could facilitate the implementation of the technique, and provideless morbidity associated with more successful peripheral nerveblock (AU)

Consideraciones sobre el bloqueo del plexo lumbar posterior en cirugía de la cadera / No disponible

No disponible

Bloqueo femoral continuo para analgesia postoperatoria en un paciente con poliomielitis / No disponible

No disponible

[Combined posterior lumbar plexus and sacral block for emergency surgery to treat hip fracture]. / Bloqueo combinado del plexo lumbar por vía posterior y plexo sacro para tratamiento quirúrgico urgente de la fractura de cadera.

Ultrasound-guided peripheral nerve blocks are being used more widely in modern anesthesiology, yet spinal anesthesia remains the most commonly used technique for lower limb surgery in general and for hip fracture in particular. A combined lumbar plexus and sacral block may provide an alternative to other local and regional anesthetic techniques in special situations such as the treatment of patients with serious concomitant disease who are on treatment that affects platelet aggregation. We report 2 cases in which patients underwent emergency surgery for hip fracture. Patient histories included serious heart and lung conditions, double antiplatelet therapy, risk factors for difficult airway, and intracranial hypertension. The aforementioned nerve block provided appropriate conditions for surgery, hemodynamic stability, and postoperative analgesia without complications.

Bloqueo combinado del plexo lumbar por vía posterior y plexosacro para tratamiento quirúrgico urgente de la fractura de cadera / Combined posterior lumbar plexus and sacral block for emergency surgery to treat hip fracture

En la actualidad, la realización de bloqueos nerviososperiféricos y el empleo de la ultrasonografía para su ejecuciónconstituyen una práctica creciente en el ámbitode la anestesiología moderna. En la cirugía de la extremidadinferior, en general, y de la fractura de la cadera,en particular, la técnica anestésica más frecuentementeempleada es la anestesia intradural. Sin embargo, el bloqueocombinado de los plexos lumbar y sacro puedeconstituir una alternativa a otras técnicas de anestesialocorregional y a la anestesia general en situacionesespeciales como las de pacientes con patología grave asociaday con tratamiento que afecta a la agregación plaquetaria.Presentamos dos casos clínicos de pacientescon indicación quirúrgica urgente por fractura de cadera,con severa cardioneumopatía y doble antiagregación,y con predictores de vía aérea difícil e hipertensiónintracraneal, en los que dicho bloqueo proporcionó adecuadascondiciones para la cirugía, estabilidad hemodinámicay analgesia postoperatoria, sin morbilidad (AU)

Ultrasound-guided peripheral nerve blocks are beingused more widely in modern anesthesiology, yet spinalanesthesia remains the most commonly used techniquefor lower limb surgery in general and for hip fracture inparticular. A combined lumbar plexus and sacral blockmay provide an alternative to other local and regionalanesthetic techniques in special situations such as thetreatment of patients with serious concomitant diseasewho are on treatment that affects platelet aggregation.We report 2 cases in which patients underwentemergency surgery for hip fracture. Patient historiesincluded serious heart and lung conditions, doubleantiplatelet therapy, risk factors for difficult airway, andintracranial hypertension. The aforementioned nerveblock provided appropriate conditions for surgery,hemodynamic stability, and postoperative analgesiawithout complications (AU)

Ultrasound-guided technique allowed early detection of intravascular injection during an infraclavicular brachial plexus block.

The reported incidence of complications after peripheral nerve blocks is generally low and varies from 0% to 5%. The injuries related to brachial plexus block are perhaps more commonly reported, than after peripheral blocks of the lower extremity nerves. Recent reports suggest that expert ultrasound guidance may reduce but not completely eliminate complications as intraneural or intravascular injection. We report a case of accidental intravascular injection of local anesthetic during infraclavicular brachial plexus block, in spite of the use of ultrasound guidance technique, and negative aspiration for blood.

Bloqueo ciático continuo con catéter estimulador guiado mediante ecografía para tratamiento del miembro fantasma doloroso / Ultrasound-guided continuous sciatic nerve block with stimulating catheter for the treatment of phantom limb pain

Los bloqueos nerviosos periféricos pueden ser una alternativa a la analgesia intravenosa y epidural en el tratamiento del miembro fantasma doloroso. La dificultad en la localización del nervio ciático mediante neuroestimulación en pacientes con arteriopatía periférica y neuropatía puede verse aumentada por el hecho de presentar una amputación del miembro inferior, que imposibilita la observación de una respuesta motora en el pie coincidiendo con la localización del nervio. En estos casos, la ecografía puede convertirse en una técnica de localización nerviosa determinante del éxito de la analgesia yaqué permite la identificación del nervio, así como la visualización en tiempo real de la posición relativa de la aguja y catéter respecto al nervio y la difusión del anestésico local administrado. Se presenta el caso de un paciente con miembro fantasma doloroso resistente al tratamiento convencional que se controló con un bloqueo ciático continuo con catéter estimulador guiado con ecografía (AU)

Peripheral nerve blocks can be an alternative to intravenous and epidural analgesia in the treatment of phantom limb pain. The difficulty of localizing the sciatic nerve through neurostimulation in patients with peripheral arteriopathy and neuropathy can eincreased by lower limb amputation, making it impossible to observe a motor response in the foot coinciding with localization of the nerve. In these cases, ultrasonography can become a technique for nerve localization and determine the success of analgesic strategy, since it allows nerve identification, as well as visualization in real time of the relative position of the needle and catheter with respect to the nerve and the diffusion of the local anesthetic administered. We report the case of a patient with phantom limb pain refractory to conventional treatment, in whom pain control was achieved by ultrasound-guided continuous sciatic block with stimulating catheter (AU)