Eficacia anestésica de la buprenorfina en la anestesia multimodal intratecal en histerectomías abdominales: ensayo clínico / Anesthetic efficacy of buprenorphine in intrathecal multimodal anesthesia in abdominal hysterectomies: clinical trial

Resumen: Introducción: La buprenorfina en la anestesia multimodal intratecal ofrece buena eficacia anestésica en histerectomías, pero por el mal entendimiento de su farmacocinética su efecto no está bien descrito. Objetivo: Evaluar la eficacia anestésica de la buprenorfina en la anestesia multimodal intratecal en histerectomías abdominales. Material y métodos: Ensayo clínico, controlado, aleatorizado, doble ciego, en mujeres programadas para histerectomía abdominal, distribuidas en tres grupos: grupo BBMD: buprenorfina 150 μg + bupivacaína hiperbárica 0.15% 4.5 mg + morfina 150 μg + dexmedetomidina 7.5 μg; grupo FBMD: fentanilo 50 μg + bupivacaína hiperbárica 0.15% 4.5 mg + morfina 150 μg + dexmedetomidina 7.5 μg; y grupo BM: bupivacaína hiperbárica 0.42% 12.5 mg + morfina 150 μg. Se evaluó la eficacia anestésica previo a la incisión, durante la disección de la pared abdominal, al ingreso a cavidad abdominal, en la entrada de compresas a cavidad abdominal, en la salida de compresas de cavidad abdominal y en el postquirúrgico inmediato. Resultados: Se analizaron 108 mujeres. Los tres grupos tuvieron muy buena eficacia anestésica; sin embargo, al salir compresas, antes de la dosis peridural y en el postquirúrgico inmediato, el grupo BM fue el que tuvo más molestias (p = 0.004, 0.01 y 0.01, respectivamente). Conclusión: La anestesia multimodal con BBMD demostró muy buena eficacia anestésica.

Abstract: Introduction: Buprenorphine in intrathecal multimodal anesthesia offers good anesthetic efficacy in hysterectomies, but due to the misunderstanding of its pharmacokinetics its effect is not well described. Objective: To evaluate the anesthetic efficacy of buprenorphine in intrathecal multiomodal anesthesia in abdominal hysterectomies. Material and methods: Controlled, randomized, double-blind clinical trial in women scheduled for abdominal hysterectomy, divided into three groups: BBMD group: buprenorphine 150 μg + hyperbaric bupivacaine 0.15% 4.5 mg + morphine 150 μg + dexmedetomidine 7.5 μg; FBMD group: fentanyl 50 μg + hyperbaric bupivacaine 0.15% 4.5 mg + morphine 150 μg + dexmedetomidine 7.5 μg; and BM group: hyperbaric bupivacaine 0.42% 12.5 mg + morphine 150 μg. Anesthetic efficacy was avaluated prior to the incision, during dissection of the abdominal wall, upon entry into the abdominal cavity, upon entry of compresses into the abdominal cavity, upon exit of compresses from the abdominal cavity, and in the immediate postoperative period. Results: 108 women were analyzed, the 3 groups had very good anesthetic efficacy, however, when the compresses come out of the cavity, the BM group had the most discomfort (p = 0.004). Conclusion: Multimodal anesthesia with BBMD demostrated very good anesthetic efficacy.

[Translated article] In vitro elution of local anaesthetics from PMMA bone cement.

BACKGROUND AND AIM: Currently, we do not have a gold standard for pain management after total knee arthroplasty. We may use one of more drug delivery systems, none of which are ideal. An ideal depot delivery system would provide therapeutic, nontoxic, doses of drug at the surgical side, especially during 72h postoperatively. The bone cement used in arthroplasties has been used as a drug delivery system, especially antibiotics, since 1970. Based on this principle, we developed this study with the aim to characterize the elution profile of two local anaesthetics (lidocaine hydrochloride and bupivacaine hydrochloride) from PMMA (polymethilmethacrylate) bone cement. MATERIAL AND METHODS: Palacos® R+G bone cement and lidocaine hydrochloride or bupivacaine hydrochloride specimens were obtained depending on the study group. These specimens were immersed in PBS (phosphate buffered saline) and removed from the solution at different set times. Subsequently, the concentration of local anaesthetic in the liquid was analyzed by liquid chromatography. RESULTS: The percentage of lidocaine eluted from PMMA bone cement in this study was 9.74% of the total lidocaine content per specimen at 72h and 18.73% at 336h (14 days). In case of bupivacaine, the elution percentage was 2.71% of the total bupivacaine content per specimen at 72h and 2.70% at 336h (14 days). CONCLUSIONS: Local anaesthetics elute in vitro from PMMA bone cement, reaching doses at 72h close to the doses used in anaesthetic blocks.

Anestesia multimodal intratecal en cesáreas, cambios que mejoran su eficacia y seguridad: ensayo clínico / Intrathecal multimodal anesthesia in caesarean sections, changes that improve its efficacy and safety: clinical trial

Resumen: Introducción: la concentración y velocidad en la administración de la anestesia multimodal intratecal con fentanilo en cesáreas mejoran la eficacia anestésica manteniendo buen control hemodinámico. Objetivo: evaluar si algunos cambios en la anestesia multimodal intratecal mejoran su eficacia y seguridad en cesáreas. Material y métodos: ensayo clínico, controlado, aleatorizado, doble ciego en mujeres embarazadas programadas para cesárea, distribuidas en tres grupos: grupo F6B2: fentanilo 65 μg + bupivacaína hiperbárica 2.5 mg + morfina 10 μg + dexmedetomidina 5 μg; grupo F6B3: fentanilo 60 μg + bupivacaína hiperbárica 3 mg+ morfina 100 μg+ dexmedetomidina 5 μg; y grupo F7B2: fentanilo 70 μg + bupivacaína hiperbárica 2 mg + morfina 100 μg + dexmedetomidina 5 μg. Se evaluó la eficacia anestésica previo a la incisión, durante la disección de la pared abdominal, al ingreso a cavidad abdominal, en la revisión de correderas parietocólicas y en el postquirúrgico inmediato, así como los signos vitales. Resultados: los grupos F6B2 y F6B3 resultaron tener mayor eficacia anestésica en la revisión de correderas parietocólicas (p = 0.02) y el grupo F7B2 el de mayor seguridad con mejor control hemodinámico a los minutos 1 y 10 (p = 0.03 y p = 0.03 respectivamente). Conclusiones: los cambios en la administración de la anestesia multimodal intratecal con fentanilo mejoraron la eficacia anestésica, pero disminuyen la seguridad sobre el control hemodinámico.

Abstract: Introduction: the concentration and speed in the administration of intrathecal multimodal anesthesia with fentanyl in cesareans section improve anesthetic efficacy while maintaining good hemodynamic control. Objective: to evaluate if some changes in intrathecal multimodal anesthesia improve its efficacy and safety in cesareans section. Material and methods: clinical trial, controlled, randomized, double blind; in pregnant women scheduled for cesarean section, divided into 3 groups: group F6B2: fentanyl 65 μg + hyperbaric bupivacaine 2.5 mg+ morphine 100 μg+ dexmedetomidine 5 μg; group F6B3: fentanyl 60 μg + hyperbaric bupivacaine 3 mg + morphine 100 μg + dexmedetomidine 5 μg; and group F7B2: fentanyl 70 μg + hyperbaric bupivacaine 2 mg + morphine 100 μg + dexmedetomidine 5 μg. The anesthetic efficacy was evaluated prior to the incision, during the dissection of the abdominal wall, upon the admission to the abdominal cavity, in the review of paracolic slides and in the immediate postoperative period, as well as the vital signs. Results: the F6B2 and F6B3 groups turned out to have greater anesthetic efficacy in the revision of paracolic slides (p = 0.02) and the F7B2 group had the highest safety with better hemodynamic control at 1 and 10 minutes (p = 0.03 and p = 0.03, respectively). Conclusions: changes in the administration of intrathecal multimodal anesthesia with fentanyl improved anesthetic efficacy, but decreased safety over hemodynamyc control.

[Translated article] In vitro elution of local anaesthetics from PMMA bone cement.

BACKGROUND AND AIM: Currently, we do not have a gold standard for pain management after total knee arthroplasty. We may use one of more drug delivery systems, none of which are ideal. An ideal depot delivery system would provide therapeutic, nontoxic, doses of drug at the surgical side, especially during 72h postoperatively. The bone cement used in arthroplasties has been used as a drug delivery system, especially antibiotics, since 1970. Based on this principle, we developed this study with the aim to characterise the elution profile of two local anaesthetics (lidocaine hydrochloride and bupivacaine hydrochloride) from PMMA (polymethilmethacrylate) bone cement. MATERIAL AND METHODS: Palacos® R+G bone cement and lidocaine hydrochloride or bupivacaine hydrochloride specimens were obtained depending on the study group. These specimens were immersed in PBS (phosphate buffered saline) and removed from the solution at different set times. Subsequently, the concentration of local anaesthetic in the liquid was analysed by liquid chromatography. RESULTS: The percentage of lidocaine eluted from PMMA bone cement in this study was 9.74% of the total lidocaine content per specimen at 72h and 18.73% at 336h (14 days). In case of bupivacaine, the elution percentage was 2.71% of the total bupivacaine content per specimen at 72h and 2.70% at 336h (14 days). CONCLUSIONS: Local anaesthetics elute in vitro from PMMA bone cement, reaching doses at 72h close to the doses used in anaesthetic blocks.

Qualitative Histologic Assessment vs. Geomorphometric Analysis of Nerve Fiber Shape after the Intraneural Application of Liposomal Bupivacaine / Evaluación Histológica Cualitativa Versus Análisis Geomorfométrico de la Forma de la Fibra Nerviosa Después de la Aplicación Intraneural de Bupivacaína Liposomal

SUMMARY: The preserved form of all components of the nerve fiber is a prerequisite for the proper conduction of the nerve impulse. various factors can change the shape of nerve fibers. In everyday practice, qualitative histological analysis is the gold standard for detecting changes in shape. Geometric morphometry is an innovative method that objectively enables the assessment of changes in nerve fibers' shape after local anesthetics action. A total of sixty sciatic nerves were used as material, which was intraneural injected with saline solution in the control group (n=30), and a solution of 1.33 % liposomal bupivacaine (n=30) in the test group. After the animals were sacrificed, nerve samples were taken and histological preparations were made. The preparations were first described and examined using a qualitative histological method, after which digital images were made. The images were entered into the MorphoJ program and processed using the method of geometric morphometry. Qualitative histological examination revealed no differences in nerve fibers after intraneurally applied physiological solution and liposomal bupivacaine. Using the method of geometric morphometry, a statistically significant change in the shape of axons was found after intraneurally applied saline solution and liposomal bupivacaine (p=0.0059). No significant differences in histological changes were found after the qualitative histological analysis of nerve fiber cross-section preparations. A statistically significant change in the shape of nerve fiber axons was observed after geometric morphometric analysis of digital images after intraneural application of saline and liposomal bupivacaine.

La forma conservada de todos los componentes de la fibra nerviosa es un requisito previo para la conducción correcta del impulso nervioso. Varios factores pueden cambiar la forma de las fibras nerviosas. En la práctica diaria, el análisis histológico cualitativo es el estándar de oro para detectar cambios de forma. La morfometría geométrica es un método innovador que permite evaluar objetivamente los cambios en la forma de las fibras nerviosas después de la acción de los anestésicos locales. Se utilizó como material un total de sesenta nervios ciáticos, que se inyectaron intraneuralmente con solución salina en el grupo control (n=30), y una solución de bupivacaína liposomal al 1,33 % (n=30) en el grupo de prueba. Después de sacrificados los animales, se tomaron muestras de nervios y se realizaron preparaciones histológicas. Primero se describieron y examinaron las preparaciones utilizando un método histológico cualitativo, después de lo cual se tomaron imágenes digitales. Las imágenes fueron ingresadas al programa MorphoJ y procesadas mediante el método de morfometría geométrica. El examen histológico cualitativo no reveló diferencias en las fibras nerviosas después de la aplicación intraneural de solución fisiológica y bupivacaína liposomal. Usando el método de morfometría geométrica, se encontró un cambio estadísticamente significativo en la forma de los axones después de la aplicación intraneural de solución salina y bupivacaína liposomal (p = 0,0059). No se encontraron diferencias significativas en los cambios histológicos después del análisis histológico cualitativo de las preparaciones de secciones transversales de fibras nerviosas. Se observó un cambio estadísticamente significativo en la forma de los axones de las fibras nerviosas después del análisis de morfometría geométrica de imágenes digitales después de la aplicación intraneural de solución salina y bupivacaína liposomal.

In vitro elution of local anesthetics from PMMA bone cement. / Estudio in vitro de elución de anestésicos locales en cemento óseo de PMMA.

BACKGROUND AND AIM: Currently, we do not have a gold standard for pain management after total knee arthroplasty. We may use one of more drug delivery systems, none of which are ideal. An ideal depot delivery system would provide therapeutic, nontoxic, doses of drug at the surgical side, especially during 72h postoperatively. The bone cement used in arthroplasties has been used as a drug delivery system, especially antibiotics, since 1970. Based on this principle, we developed this study with the aim to characterize the elution profile of two local anesthetics (lidocaine hydrochloride and bupivacaine hydrochloride) from PMMA (polymethilmethacrylate) bone cement. MATERIAL AND METHODS: Palacos® R+G bone cement and lidocaine hydrochloride or bupivacaine hydrochloride specimens were obtained depending on the study group. These specimens were immersed in PBS (phosphate buffered saline) and removed from the solution at different set times. Subsequently, the concentration of local anesthetic in the liquid was analyzed by liquid chromatography. RESULTS: The percentage of lidocaine eluted from PMMA bone cement in this study was 9.74% of the total lidocaine content per specimen at 72h and 18.73% at 336h (14 days). In case of bupivacaine, the elution percentage was 2.71% of the total bupivacaine content per specimen at 72h and 2.70% at 336h (14 days). CONCLUSIONS: Local anesthetics elute in vitro from PMMA bone cement, reaching doses at 72h close to the doses used in anesthetic blocks.

Descripción de analgesia de parto con lidocaína o bupivacaina y Apgar al nacer. Estudio observacional descriptivo retrospectivo

El trabajo de parto lleva con este la experiencia que causa uno de los dolores más intensos que se han descrito. En el Instituto de Seguridad Social de El Salvador (ISSS) se registran aproximadamente 600 a 700 partos vaginales por mes y de estos aproximadamente 10-20% solicitan analgesia para trabajo de parto, la cual el servicio de anestesia provee a través del abordaje epidural. Es conocido que se considera que el medicamento ideal para la analgesia de trabajo de parto es la bupivacaína o lidocaína 3, sin embargo, es de especial importancia describir el puntaje de APGAR de los recién nacidos de madres que recibieron cualquiera de estos dos fármacos por la vía ya mencionada. Objetivo: Determinar cómo influye el uso de lidocaína y bupivacaína como anestésico epidural sobre el puntaje APGAR posterior al nacimiento en mujeres embarazadas en fase activa del trabajo de parto con necesidad de analgesia epidural. Métodos: El presente es un estudio observacional descriptivo retrospectivo de fuentes primarias. El servicio de anestesiología del Hospital Materno Infantil Primero de Mayo cuenta con un registro sobre cuántos y a cuáles pacientes se les administra analgesia epidural por lo que el equipo investigador realizó una revisión de la técnica anestésica y se describe el Apgar al final del parto por vía vaginal en aquellas pacientes que recibieron analgesia epidural con lidocaína o bupivacaína. Se realizó el filtrado con la base de datos de Excel utilizando criterios de inclusión y exclusión, logrando incluir finalmente 81 pacientes en el análisis de los datos. Se encontró durante el escrutinio de estos que a 25 de estas se les realizó cesárea de emergencia y en 6 de estos mismos expedientes no se consignó de manera completa todos los datos necesarios para el análisis de ello, por lo que se utilizaron finalmente 51 expedientes clínicos para la realización de la presente investigación. Resultados: El APGAR promedio de los pacientes que recibieron analgesia de trabajo de parto con bupivacaína es de 8.75 y 8.9 al minuto y cinco minutos respectivamente y el promedio de APGAR alcanzado por los recién nacidos de pacientes que recibieron analgesia de trabajo de parto con lidocaína es de 9 puntos al minuto y cinco minutos. Conclusión: El promedio de APGAR en pacientes que recibieron bupivacaína es de 8.75 y el de lidocaína es de 9. (provisto por Infomedic International)

Labor brings with it the experience that causes one of the most intense pains ever described. At the Social Security Institute of El Salvador (ISSS) approximately 600 to 700 vaginal deliveries are registered per month and of these approximately 10-20% request labor analgesia, which the anesthesia service provides through the epidural approach. It is known that the ideal drug for labor analgesia is considered to be bupivacaine or lidocaine 3, however, it is of special importance to describe the APGAR score of newborns born to mothers who received either of these two drugs by the aforementioned route. Objective: To determine how the use of lidocaine and bupivacaine as epidural anesthetic influences the post-birth APGAR score in pregnant women in the active phase of labor requiring epidural analgesia. Methods: The present is a retrospective descriptive observational observational study from primary sources. The anesthesiology service of the Hospital Materno Infantil Primero de Mayo has a record of how many and to which patients epidural analgesia is administered, so the research team conducted a review of the anesthetic technique and described the Apgar at the end of vaginal delivery in those patients who received epidural analgesia with lidocaine or bupivacaine. Filtering was performed with the Excel database using inclusion and exclusion criteria, finally including 81 patients in the data analysis. It was found during the scrutiny of these that 25 of them had undergone emergency cesarean section and in 6 of these same records not all the data necessary for the analysis were completely recorded, so that 51 clinical records were finally used for the present investigation. Results: The average APGAR of the patients who received labor analgesia with bupivacaine was 8.75 and 8.9 at one minute and five minutes respectively, and the average APGAR achieved by the newborns of patients who received labor analgesia with lidocaine was 9 points at one minute and five minutes. Conclusion: The average APGAR in patients who received bupivacaine is 8.75 and that of lidocaine is 9. (provided by Infomedic International)

Anestesia raquídea con bupivacaína isobárica en cesáreas / Spinal anesthesia with isobaric bupivacaine in cesarean sections

En la anestesia para las cesáreas, la anestesia raquídea con bupivacaína hiperbárica constituye la elección habitual en nuestro medio. Existen dos formas de bupivacaína disponibles, la isobárica (BI) y la hiperbárica (BH). La utilización de la BI es poco frecuente por lo que es relevante conocer la experiencia en su utilización para las anestesias de las cirugías obstétricas. El objetivo del estudio fue caracterizar la utilización de BI en las anestesias raquídeas para cesáreas. Se realizó un estudio observacional, descriptivo, de corte transversal en 23 pacientes que recibieron anestesia espinal con BI. La edad promedio fue de 28  5 años, la dosis promedio de BI utilizada de 9,4 mg. La latencia promedio fue 90 segundos y el tiempo para la instauración una anestesia adecuada fue en promedio 4,9 minutos. En el 82,6% el nivel anestésico alcanzó el dermatoma T4. En el 21,7% fue necesario administrar efedrina para aumentar la presión arterial. En el 52,1% se presentaron efectos adversos menores. A las 24 horas, el dolor fue nulo en 56,5% y leve en 43,5% de los casos. En conclusión, se encontró que las pacientes alcanzaron un nivel sensitivo adecuado en poco tiempo, con una dosis promedio de BI de 9 mg. Pocos pacientes requirieron la administración de un vasopresor para aumentar la presión arterial. Los efectos adversos fueron menores en casi la mitad de los pacientes. En el post operatorio la mayoría de las pacientes no presentaron dolor

In anesthesia for caesarean sections, spinal anesthesia with hyperbaric bupivacaine is the usual choice in our setting. There are two forms of bupivacaine available, isobaric (BI) and hyperbaric (BH). The use of BI is infrequent, so it is relevant to know the experience in its use for anesthesia in obstetric surgeries. The objective of the study was to characterize the use of BI in spinal anesthesia for cesarean sections. An observational, descriptive, cross-sectional study was carried out in 23 patients who received spinal anesthesia with BI. The average age was 28  5 years, the average dose of BI used was 9.4 mg. The average latency was 90 seconds and the time for establishment of adequate anesthesia was on average 4.9 minutes. In 82.6% of the cases, the anesthetic level reached dermatome T4. In 21.7% it was necessary to administer ephedrine to increase blood pressure. Minor adverse effects occurred in 52.1%. At 24 hours, the pain was null in 56.5% and mild in 43.5% of cases. In conclusion, it was found that the patients reached an adequate sensory level in a short time, with an average dose of BI of 9 mg. Few patients required administration of a vasopressor to increase blood pressure. Adverse effects were minor in almost half of the patients. In the postoperative period, most of the patients did not present pain

Anestesia espinal con bupivacaína más morfina en cirugía de urgencia de fractura intertrocantérica de cadera / Spinal anesthesia with bupivacaine plus morphine in urgent intertrochanteric hip fracture surgery

Introducción: La fractura de cadera en el anciano es una entidad frecuente y tiene gran incidencia en el mundo y en Cuba por el envejecimiento. Objetivo: Evaluar la eficacia de la anestesia espinal con bupivacaína más morfina en la cirugía de fractura intertrocantérica de cadera. Métodos: Se realizó un estudio clínico, experimental, no aleatorizado, prospectivo y de corte longitudinal en el Hospital Universitario Faustino Pérez Hernández de Matanzas de octubre de 2017 a octubre de 2019. El universo estuvo conformado por todos los pacientes quirúrgicos con fractura de cadera del hospital. La muestra se realizó por muestreo intencional, por 120 pacientes elegidos a criterio de los investigadores. Grupo control (B): Anestesia subaracnoidea con bupivacaína 0,5 por ciento 10 mg. Grupo estudio (M): Anestesia subaracnoidea con bupivacaína 0,5 por ciento 7 mg más 0,2 mg de morfina. Cada grupo estuvo integrado por 60 pacientes. Las variables analizadas fueron las siguientes: grupos de edades, género, estado físico, nivel de punción, tiempo de inicio del bloqueo motor, hipotensión arterial, uso de vasopresores y complicaciones secundarias a la técnica anestésica. Resultados: Predominó grupo de 84 y 90 años, género femenino y ASA III. La punción lumbar se realizó entre L3-L4. El tiempo de inicio del bloqueo motor fue 1,3 veces menor en el grupo M. Prevaleció la hipotensión arterial en el grupo B; y uso de vasopresores en ambos grupos. Predominó el prurito, grupo M, y la bradicardia, grupo B como complicaciones. Conclusiones: La asociación bupivacaína/morfina en anestesia espinal en adulto mayor para fractura de cadera proporciona mejores resultados sin complicaciones mayores(AU),

Introduction: Hip fracture in the elderly patient is a frequent entity with a high incidence worldwide and in Cuba due to aging. Objective: To assess the efficacy of spinal anesthesia with bupivacaine plus morphine in intertrochanteric hip fracture surgery. Methods: A clinical, experimental, nonrandomized, prospective, prospective and longitudinal study was carried out in Faustino Pérez Hernández University Hospital of Matanzas, from October 2017 to October 2019. The universe consisted of all surgical patients with hip fracture attended in the hospital. The sample was made by purposive sampling, consisting of 120 patients chosen at the discretion of the researchers. The control group (B) was administered subarachnoid anesthesia with 10 mg of bupivacaine 0.5 percent. The study group (M) was administered subarachnoid anesthesia with 7 mg of bupivacaine 0.5 percent. plus 0.2 mg of morphine. Each group consisted of 60 patients. The following variables were analyzed: age groups, gender, physical condition, puncture level, motor block onset time, arterial hypotension, use of vasopressors, and complications secondary to the anesthetic technique. Results: The predominant age group was 84 and 90 years old, together with female gender and ASA III. Lumbar puncture was performed between L3 and L4. The motor block onset time was 1.3 times shorter in the M group. Arterial hypotension prevailed in the B group; apart from the use of vasopressors in both groups. As complications, there was a predominance of pruritus in the M group and bradycardia in the B group. Conclusions: The association bupivacaine/morphine in spinal anesthesia for hip fracture among elderly adults provides better outcomes without major complications(AU)

Tratamiento farmacológico del estrabismo / Pharmacological treatment of strabismus

La cirugía de la musculatura extraocular ha sido el estándar de atención para tratamiento quirúrgico del estrabismo por más de un siglo. A pesar del gran desarrollo técnico de la cirugía de estrabismo en la actualidad, la utilización de microscopio quirúrgico, el diseño novedoso del instrumental quirúrgico, la calidad de la sutura no reabsorbible; los avances en equipamiento y fármacos anestésicos, la misma no está exenta de complicaciones quirúrgicas, además del tiempo de recuperación que necesita el paciente para reincorporarse a sus actividades sociales, han propiciado una búsqueda permanente del tratamiento farmacológico para el estrabismo. El objetivo de esta revisión bibliográfica es analizar las distintas alternativas farmacológicas disponibles como tratamiento del estrabismo. Para su confección se consultó textos completos y artículos en idiomas español e inglés, disponible en algunas bases de datos. Concluimos que aunque se han estudiado numerosos fármacos, la toxina botulínica que es la más conocida y utilizada mundialmente, seguida de la bupivacaína. Encontramos otros como la IGF I y II (Insuline Growing Factor), capaces de generar un efecto de reforzamiento de la actividad muscular. Y otros que "debilitan" la musculatura extraocular, incluyen la mAb35-Rubicina, BMP4 (Proteína morfogénica ósea). Se continúa su investigación en la actualidad(AU)

Extraocular musculature surgery has been the standard of care for surgical treatment of strabismus for more than a century. Despite the great technical development of strabismus surgery today, the use of a surgical microscope, the novel design of surgical instruments, the quality of the non-absorbable suture; Advances in anesthetic equipment and drugs, it is not exempt from surgical complications, in addition to the recovery time that the patient needs to return to their social activities, have led to a permanent search for pharmacological treatment for strabismus. The objective of this bibliographic review is to analyze the different pharmacological alternatives available as a treatment for strabismus. For its preparation, full texts and articles in Spanish and English languages were consulted, available in some databases. We conclude that although numerous drugs have been studied, botulinum toxin, which is the best known and used worldwide, followed by bupivacaine. We find others such as IGF I and II (Insuline Growing Factor), capable of generating an effect of reinforcing muscle activity. And others that "weaken" MOE include mAb35-Rubicin, BMP4 (Bone Morphogenic Protein). His research is continuing today(AU)

Infiltração de anestésicos locais na ferida cirúrgica: efeito sobre a inflamação e cicatriz fibrosa em ratos / Infiltration of local anesthetics into the surgical wound: effect on inflammation and fibrous scar in rats

■ RESUMO Introdução: O alívio da dor após a cirurgia continua sendo um dos desafios médicos mais significativos, principalmente na cirurgia estética. A infiltração da incisão cirúrgica com anestésicos locais tem sido cada vez mais utilizada para reduzir a dor e o uso de analgésicos. No entanto, pouco se sabe sobre o efeito desta injeção na cicatrização. O objetivo é avaliar a interferência dos anestésicos locais na área de infiltrado inflamatório e cicatriz de fibrose em ratos. Métodos: Duas incisões lineares foram feitas cada uma na região dorsal de 40 ratos Wistar. A incisão esquerda foi infiltrada com doses de 1,8ml de bupivacaína, levobupivacaína, ropivacaína ou solução salina 0,9%. A incisão direita não recebeu infiltração, servindo como grupo controle. Após sete dias, amostras das incisões foram coletadas para avaliação morfométrica histológica. Resultados: Quando comparada com os grupos controle, a área de infiltrado inflamatório encontrada foi maior nos grupos bupivacaína, ropivacaína e levobupivacaína. O grupo bupivacaína apresentou um infiltrado inflamatório maior do que a levobupivacaína e a ropivacaína. A área da cicatriz fibrosa foi maior nos grupos levobupivacaína e ropivacaína. Não houve diferença entre os grupos que receberam anestésico e solução salina. Conclusão: Como não houve diferença entre os grupos de anestésico e soro fisiológico, o volume aplicado ou o trauma podem ter sido a causa das maiores áreas de infiltração e cicatriz associadas à aplicação dos anestésicos locais.

■ ABSTRACT Introduction: Pain relief after surgery remains one of the most significant medical challenges, mainly in aesthetic surgery. The infiltration of the surgical incision with local anesthetics has been increasingly used to reduce pain and other analgesic use. However, little is known about the effect of this injection on healing. The objective is to evaluate the interference of local anesthetics in the area of inflammatory infiltrate and fibrosis scar in rats. Methods: Two linear incisions each were made on the dorsal region of 40 Wistar rats. The left incision was infiltrated with doses of 1.8ml of bupivacaine, levobupivacaine, ropivacaine, or 0,9% saline solution infiltration. The right incision did not receive infiltration, serving as a control group. After seven days, samples of the incisions were collected for histological morphometric evaluation. Results: When compared with the control groups, the area of inflammatory infiltrate was found larger in the bupivacaine, ropivacaine, and levobupivacaine groups. The bupivacaine group presented a larger inflammatory infiltrate than the levobupivacaine and ropivacaine. The fibrous scar area was larger in the levobupivacaine and ropivacaine groups. There was no difference between the groups that received anesthetic and saline solution. Conclusion: As there was no difference between the anesthetics and saline solution groups, the volume applied, or the trauma may have been the cause of the larger areas of infiltrating and scar associated with local anesthetics application.

Analysis of bupivacaine and ropivacaine-related cardiac arrests in regional anesthesia: A systematic review of case reports.

Regional anesthesia as a component of multimodal analgesia protocols has become more and more a part of modern perioperative pain management. The widespread adoption of ultrasound guidance in regional anesthesia has surely played an important role in that growth and it has significantly improved patient safety, decreased the incidence of block failure, cardiac arrest, and reduced complication rates. The objective of this systematic review is to extract, analyze, and synthesize clinical information about bupivacaine and ropivacaine related cardiac arrest that we might have a clearer picture of the clinical presentation. The literature search identified 268 potentially relevant publications and 22 relevant case reports were included in the review. Patients' demographics, types of regional anesthesia, hypotension, heart rhythm disorders, seizures, cardiac arrest, fatal outcome, recommendations and limitations on prevention and treatment of bupivacaine and ropivacaine related cardiac arrest are analyzed and discussed in the systematic review. Both bupivacaine and ropivacaine-induced local anesthetic toxicity can result in cardiac arrest. Lipid emulsion, telemetry, local anesthetic toxicity resuscitation training appears to be promising in improvement of survival but more research is needed. Improvement and encouragement of reporting the local anesthetic toxicity are warranted to improve the quality of information that can be analyzed in order to make more precise conclusion.

Epidural anesthesia for cesarean section with 0.125% versus 0.25% bupivacaine: An Ecuadorian prospective cohort.

ANTECEDENTES: En una cesárea se puede emplear analgesia epidural con bupivacaína 0.125% and lidocaína 1.5% ó bupivacaína 0.25% and lidocaína 1.0%. Una concentración mayor de bupivacaína alcanza mayor analgesia con más eventos adversos. OBJETIVO: evaluar la analgesia y seguridad de bupivacaína 0.125% and lidocaína 1.5% ó bupivacaína 0.25% and lidocaína 1.0%. MATERIALES Y MÉTODOS: Cohorte prospectivo estratificado según ambas concentraciones de bupivacaína. RESULTADOS: Se recuperó cien gestantes a término (cincuenta por cohorte). A los 20 y 30 minutos tras la administración epidural hubo más casos con mayor bloqueo motor en quienes se empleó bupivacaína 0.125% and lidocaína 1.5% (p = 0.0229 y p = 0.0006, respectivamente). No hubo diferencia significativa respecto al bloqueo sensitivo. Bupivacaína 0.25% and lidocaína 1.5% mostró una tencencia a la hipotensión (p < 0.001) y a la bradicardia (p = 0.4100). De la cohorte de bupivacaína 0.125% and lidocaína 1.5%, 25 casos (50%) presentaron cuando menos un evento adverso, en contraste con 44/50 (88%) de la cohorte de bupivacaína 0.25% and lidocaína 1.0% (p < 0.001). CONCLUSIÓN: En la analgesia epidural durante cesárea, bupivacaína 0.125% and lidocaína 1.5% está asociado con un efecto analgésico similar a bupivacaína 0.25% and lidocaína 1.0%. Sin embargo, mayores concentraciones están significativamente relacionadas con mayor tasa de eventos adversos (especialmente hipotensión). BACKGROUND: In a cesarean section, epidural analgesia with 0.125% bupivacaine and 1.5% lidocaine or 0.25% bupivacaine with 1.0% lidocaine concentrations can be used. A higher concentration of bupivacaine reaches better analgesia but with a higher rate of drug-related adverse events. AIM: The aim of the study was to assess analgesia and safety of 0.125% bupivacaine and 1.5% lidocaine or 0.25% bupivacaine with 1.0% lidocaine during cesarean. MATERIALS AND METHODS: Prospective cohort stratified following both bupivacaine concentrations. RESULTS: One hundred women with full-term pregnancies were selected (fifty per cohort). At 20 and 30 min after epidural administration, there was a higher proportion of motor blockade cases from the 0.125% bupivacaine and 1.5% lidocaine cohort (p = 0.0229 and p = 0.0006, respectively). There was no significant difference among sensitive blockage. A 0.25% bupivacaine and 1.0% lidocaine concentration showed a tendency to hypotension (p < 0.001) and bradycardia (p = 0.4100). From 0.125% bupivacaine and 1.5% lidocaine cohort, 25 cases (50%) presented at least one adverse event; in contrast with 44/50 (88%) from 0.25% bupivacaine and 1.0% lidocaine cohort (p < 0.001). CONCLUSION: In epidural analgesia during cesarean, using 0.125% bupivacaine and 1.5% lidocaine presented similar analgesia than 0.25% bupivacaine and 1.0% lidocaine. However, a higher bupivacaine concentration is significantly related to more frequent drug-related adverse events (especially hypotension).

Síndrome de cauda equina posterior a la administración por vía subaracnoidea de bupivacaina hiperbárica al 0, 75 % / Cauda equina syndrome following subarachnoid administration of hyperbaric bupivacaine 0. 75 %

El síndrome de cauda equina es una patología poco frecuente en el área de anestesiología. Esta se caracteriza por presentar un conjunto de signos y síntomas que involucran: dolor, disminución o abolición de la fuerza muscular, disfunción de esfínteres e hipoestesia de silla de montar. El objetivo del presente trabajo es presentar y discutir el caso clínico de una paciente con diagnóstico de síndrome de cauda equina posterior a la administración por vía subaracnoidea de bupivacaina al 0,75 % hiperbárica. Se trata de paciente femenina de 42 años a quien se le realizó cesárea segmentaria y salpingectomia bilateral con bloqueo anestésico subaracnoideo; y quien posteriormente a las dieciséis horas del posoperatorio presentó: disminución de la fuerza muscular de miembros inferiores e hipoestesia de región de silla de montar, reflejo rotuliano: 0/4 bilateral y retención urinaria. Se le inicia tratamiento farmacológico y fisiátrico inmediatamente establecido el diagnóstico de síndrome de cauda equina. La paciente fue dada de alta el día diez del posoperatorio, con disminución significativa de la clínica antes descrita, evidenciándose posteriormente retención urinaria por lo que requirió sondaje vesical intermitente. Una vez establecido el diagnostico se instaló inmediatamente tratamiento farmacológico y fisiátrico para dar una oportuna resolución de la patología(AU)

Cauda equina syndrome is a rare pathology in the area of anesthesiology. This is characterized by presenting a set of signs and symptoms that involve: pain, decrease or abolition of muscle strength, sphincter dysfunction and saddle hypoesthesia. The objective of this work is to present and discuss the clinical case of a patient with a diagnosis of cauda equina syndrome after the administration of hyperbaric 0.75% bupivacaine via the subarachnoid route. This is a 42-year-old female patient who underwent segmental cesarean section and bilateral salpingectomy with subarachnoid anesthetic block; and who subsequently at sixteen hours postoperatively presented: decreased muscle strength, lower limbs and hypoesthesia of the saddle region, knee jerk reflex: bilateral 0/4 and urinary retention. Pharmacological and physical treatment was started immediately, the diagnosis of cauda equina syndrome was established. The patient was discharged on postoperative day 10, with a significant decrease in the symptoms described above, later evidence of urinary retention, requiring intermittent bladder catheterization. Once the diagnosis was established, pharmacological and physiatric treatment was immediately installed to give a timely resolution of the pathology(AU)

Analgesia posoperatoria en la videolaparascopía de urgencia mediante irrigación de bupivacaína intraperitoneal / Posoperative analgesia in emergency videolaparoscopy through intraperitoneal bupivacaine irrigation

Introducción: La videolaparascopía es un procedimiento frecuente en los servicios de urgencias de cirugía general. El dolor agudo después de estas intervenciones es de naturaleza compleja y requiere un tratamiento analgésico efectivo. Objetivo: Determinar la utilidad del empleo de bupivacaína intraperitoneal en el alivio del dolor posoperatorio en la videolaparascopía de urgencia. Métodos: Se realizó un estudio longitudinal prospectivo y analítico en 80 pacientes mayores de 18 años, anunciados para videolaparoscopía bajo anestesia general orotraqueal en el servicio de urgencias del HMC: Dr. Luis Díaz Soto, desde septiembre de 2016 hasta septiembre de 2018. Los pacientes fueron divididos aleatoriamente en dos grupos de 40 cada uno. Al grupo 1 se aplicó lidocaína transdérmica preincisional en las incisiones de piel y, al término de la cirugía, se irrigaron ambos hemidiafragmas con bupivacaína al 0,25 por ciento. Al grupo 2 se le administró dosis preincisional de analgésicos endovenosos solamente. Resultados: Predominó significativamente el sexo femenino sin diferencia entre grupos. La analgesia posoperatoria fue mejor en el grupo 1 estadísticamente significativa a las 4, 8 y 12 horas. Los requerimientos de analgesia de rescate fueron menores en el grupo 1 (p=0,0024). No se reportaron efectos adversos. Conclusiones: La administración de lidocaína transdérmica preincisional y la instilación de bupivacaína intraperitoneal al final de la videolaparoscopía de urgencia, reduce significativamente el dolor en las primeras horas de posoperatorio. Su aplicación es sencilla, fácil y segura sin evidencias de efectos adversos(AU)

Introduction: Videolaparoscopy is a frequent general surgery procedure in emergency services. Acute pain after these interventions is complex in nature and requires effective analgesic treatment. Objective: To determine the usefulness of intraperitoneal bupivacaine in the relief of postoperative pain in emergency videolaparoscopy. Methods: A prospective, analytical and longitudinal study was carried out in eighty patients older than eighteen years old, announced for videolaparoscopy under orotracheal general anesthesia in the emergency department of Hospital Militar Central Dr. Luis Díaz Soto, from September 2016 to September 2018. The patients were randomly divided into two groups of forty individuals each. Group 1 was applied pre-incisional transdermal lidocaine on skin incisions and, at the end of surgery, both hemidiaphragms were irrigated with bupivacaine 0.25 percent. Group 2 received pre-incisional doses of intravenous analgesics only. Results: The female sex predominated significantly, without difference between the two groups. Postoperative analgesia was better in group 1, insofar it was statistically significant at four, eight and twelve hours. Rescue analgesia requirements were lower in group 1 (p=0.0024). No adverse effects were reported. Conclusions: The administration of pre-incisional transdermal lidocaine and the instillation of intraperitoneal bupivacaine at the end of emergency videolaparoscopy significantly reduces pain during the first hours after surgery. Its application is simple, easy and safe, without evidence of adverse effects(AU)

Bupivacaine-induced myotoxicity during a continuous perineural femoral block: case report / Miotoxicidad inducida por bupivacaína durante un bloqueo continuo del nervio femoral: reporte de caso

Abstract Introduction: Regional anesthesia is widely used for postopera tive analgesia in total knee arthroplasty (TKA). Although it is a safe and effective procedure, serious complications may still develop. In the event of an unusual or torpid evolution, the possibility of local anesthetic-induced myotoxicity should be suspected. Case presentation: A 54-year old patient, American Society of Anesthesiologists (ASA) II, underwent TKA due to primary gonarthrosis.. The analgesic technique used was a femoral nerve block associated with continuous perineural infusion. 24 hours later, the patient's medical condition deteriorated presenting pain, edema, and functional limitation of the thigh of the operated extremity. The symptoms were suggestive of myotoxicity, confirmed with diagnostic images leading to the removal of the catheter. The patient experienced then a significant improvement and was discharged 5 days after surgery. Conclusion: The diagnosis of myotoxicity from local anes thetics is rare, since its manifestations may be masked by the usual symptoms of the postoperative period. Early identification of the condition is fundamental to reduce its negative impact on the patient's recovery and satisfaction. Since the scope of the damage depends particularly on the concentration and duration of the exposure to the local anesthetic agent, there is a need to implement protocols that enable an effective block with the lowest concentration and volume of the medication.

Resumen Introducción: La anestesia regional es ampliamente usada para la analgesia posoperatoria en la Artroplastia de Reemplazo de Rodilla (ARR). Aunque son procedimientos seguros y efectivos, la posibilidad de complicaciones graves existe. Ante una evolución inusual o tórpida se debe sospechar la posibilidad de miotoxicidad inducida por anestésicos locales. Presentación del caso: En un paciente de 54 años, American Society of Anesthesiologists (ASA) II, se llevó a cabo ARR por gonartrosis primaria. Como técnica analgésica se usó el bloqueo de nervio femoral asociado a infusión continua perineural. 24 horas después el paciente presenta deterioro clínico dado por dolor, edema y limitación funcional en muslo de extremidad operada. Ante síntomas sugestivos de miotoxicidad confirmada por imágenes diagnósticas, el catéter fue retirado. Posteriormente, presentó una mejoría significa tiva y egresó del hospital al quinto día posoperatorio. Conclusiones: El diagnóstico de miotoxicidad por anestésicos locales es poco frecuente debido a que sus manifestaciones pueden estar enmascaradas por los síntomas habituales durante el periodo posoperatorio. Su identificación temprana es funda mental para disminuir el efecto negativo sobre la recuperación y la satisfacción del paciente. Dado que la magnitud del daño depende especialmente de la concentración y la duración de la exposición al anestésico local, es necesario implementar proto colos que permitan lograr un bloqueo efectivo con la menor concentración y volumen posible del medicamento.

[Antimicrobial effects of fentanyl and bupivacaine]. / Efeitos antimicrobianos do fentanil e da bupivacaína: estudo in vitro.

STUDY OBJECTIVE: In this study, we aimed to compare the antimicrobial effects of bupivacaine and fentanyl citrate and to reveal the impact on antimicrobial effect potential in the case of combined use. DESIGN: In vitro prospective study. SETTING: University Clinical Microbiology Laboratory. MEASUREMENTS: In our study, in vitro antimicrobial effect of 0.05 mg.mL-1 fentanyl citrate, 5 mg.mL-1 bupivacaine were tested against Staphylococcus aureus American Type Culture Collection (ATCC) 29213, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 13883, Escherichia coli ATCC 25922 and Candida albicans ATCC 10231 as Group F (Fentanyl Citrate) and Group B (Bupivacaine), respectively. S. aureus ATCC 29213, P. aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 13883 and Escherichia coli ATCC 25922 were cultured onto Mueller Hinton agar (Oxoid, UK) plates and Candida albicans ATCC 10231 were cultured onto Sabouraud dextrose agar (Oxoid, UK) plates for 18-24 hours at 37°C. MAIN RESULTS: In terms of inhibition zone diameters, S. Aureus ATCC 29213, P. aeruginosa ATCC 27853, and C. albicans ATCC10231 values obtained after 12 and 24 hours of incubation were significantly higher in Group F than Group B (p < 0.001). In terms of inhibition zone diameters, E. coli ATCC 25922, and K. pneumomiae ATCC 13883 values obtained after 12 and 24hours of incubation were significantly higher in Group B than Group F (p < 0.001, E. coli 12ª hour p = 0.005). CONCLUSIONS: Addition of fentanyl to Local Anesthetics (LAs) is often preferred in regional anesthesia applications in today's practice owing especially to its effect on decreasing the local anesthetic dose and increasing analgesia quality and patient satisfaction. However, when the fact that fentanyl antagonized the antimicrobial effects of LAs in the studies is taken into account, it might be though that it contributes to an increase in infection complications. When the fact that fentanyl citrate, which was used in our study and included hydrochloric acid and sodium hydroxide as protective agents, broadened the antimicrobial effect spectrum of LAs, had no antagonistic effect and showed a synergistic antimicrobial effect against E. Coli is considered, we are of the opinion that the addition of fentanyl to LAs would contribute significantly in preventing the increasing regional anesthesia infection complications.

Antimicrobial effects of fentanyl and bupivacaine: an in vitro study / Efeitos antimicrobianos do fentanil e da bupivacaína: estudo in vitro

Abstract Study objective: In this study, we aimed to compare the antimicrobial effects of bupivacaine and fentanyl citrate and to reveal the impact on antimicrobial effect potential in the case of combined use. Design: In vitro prospective study. Setting: University Clinical Microbiology Laboratory. Measurements: In our study, in vitro antimicrobial effect of 0.05 mg.mL-1 fentanyl citrate, 5 mg.mL-1 bupivacaine were tested against Staphylococcus aureus American Type Culture Collection (ATCC) 29213, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 13883, Escherichia coli ATCC 25922 and Candida albicans ATCC 10231 as Group F (Fentanyl Citrate) and Group B (Bupivacaine), respectively. S. aureus ATCC 29213, P. aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 13883 and Escherichia coli ATCC 25922 were cultured onto Mueller Hinton agar (Oxoid, UK) plates and Candida albicans ATCC 10231 were cultured onto Sabouraud dextrose agar (Oxoid, UK) plates for 18-24 hours at 37 °C. Main results: In terms of inhibition zone diameters, S. Aureus ATCC 29213, P. aeruginosa ATCC 27853, and C. albicans ATCC10231 values obtained after 12 and 24 hours of incubation ​​were significantly higher in Group F than Group B (p < 0.001). In terms of inhibition zone diameters, E. coli ATCC 25922, and K. pneumomiae ATCC 13883 values obtained after 12 and 24 hours of incubation ​​were significantly higher in Group B than Group F (p < 0.001, E. coli 12ª hour p = 0.005). Conclusions: Addition of fentanyl to Local Anesthetics (LAs) is often preferred in regional anesthesia applications in today's practice owing especially to its effect on decreasing the local anesthetic dose and increasing analgesia quality and patient satisfaction. However, when the fact that fentanyl antagonized the antimicrobial effects of LAs in the studies is taken into account, it might be though that it contributes to an increase in infection complications. When the fact that fentanyl citrate which was used in our study and included hydrochloric acid and sodium hydroxide as protective agents, broadened the antimicrobial effect spectrum of LAs, had no antagonistic effect and showed a synergistic antimicrobial effect against E. Coli is considered, we are of the opinion that the addition of fentanyl to LAs would contribute significantly in preventing the increasing regional anesthesia infection complications.

Resumo Objetivo: O objetivo do presente estudo foi comparar os efeitos antimicrobianos da bupivacaína e citrato de fentanil e revelar o impacto no potencial do efeito antimicrobiano no caso de uso combinado. Desenho: Estudo prospectivo in vitro. Local: Laboratório de Microbiologia Clínica da Universidade. Medidas: Em nosso estudo, os efeitos antimicrobianos in vitro do citrato de fentanil na concentração de 0,05 mg.mL-1 - Grupo F e da bupivacaína na concentração de 5 mg.mL-1 - Grupo B foram testados em culturas de Staphylococcus aureus ATCC 29213 (do inglês American Type Culture Collection 29213), Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 13883, Escherichia coli ATCC 25922 e Candida albicans ATCC 10231. As culturas de S. aureus ATCC 29213, P. aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 13883 e Escherichia coli ATCC 25922 foram semeadas em placas de ágar Mueller Hinton (Oxoid, Reino Unido), e a cultura de Candida albicans ATCC 10231 foi realizada em placa de ágar Sabouraud dextrose (Oxoid, Reino Unido) durante 18-24 horas a 37 °C. Principais resultados: Com relação ao diâmetro da zona de inibição, os valores de S. aureus ATCC 29213, P. aeruginosa ATCC 27853 e C. albicans ATCC10231 obtidos após 12 e 24 horas de incubação foram significantemente maiores no Grupo F do que no Grupo B (p < 0,001). Os valores do diâmetro da zona de inibição das culturas de E. coli ATCC 25922 e K. pneumomiae ATCC 13883 obtidos após 12 e 24 horas de incubação foram significantemente maiores no Grupo B do que no Grupo F (p < 0,001, E. coli na 12ª hora p = 0,005) Conclusões: A preferência atual e frequente pela adição de fentanil aos Anestésicos Locais (AL) para a realização de anestesia regional se deve sobretudo à possibilidade de redução da dose do anestésico local, a melhora na qualidade da analgesia e a satisfação do paciente. No entanto, ao considerar estudos em que o fentanil antagonizou o efeito antimicrobiano dos AL, pode-se pensar que esse fato contribua para aumento de complicação infecciosa. O citrato de fentanil usado em nosso estudo, contendo ácido clorídrico e hidróxido de sódio como agentes conservantes, ampliou o espectro de efeitos antimicrobianos dos AL, não teve efeito antagônico e demonstrou efeito antimicrobiano sinérgico contra a E. coli. Acreditamos que a adição de fentanil aos anestésicos locais traria importante contribuição na prevenção das crescentes complicações por infecção da anestesia regional.

[Influence of different local anesthetics on atracurium neuromuscular blockade on rats]. / Influência de diferentes anestésicos locais no bloqueio neuromuscular produzido pelo atracúrio em ratos.

INTRODUCTION: The association between Local Anesthetics (LAs) and Neuromuscular Blocking (NMB) drugs in clinical practice, and the possibility of interaction between these drugs has been investigated. LAs act on neuromuscular transmission in a dose-dependent manner and may potentiate the effects of NMB drugs. OBJECTIVE: The aim of this study was to evaluate, in an experimental model, the effect of lidocaine and racemic bupivacaine on neuromuscular transmission and the influence on neuromuscular blockade produced by atracurium. METHODS: Male Wistar rats, weighing from 250 g to 300g were used. The preparation was set up based on a technique proposed by Bülbring. Groups were formed (n = 5) according to the drug studied: lidocaine 20 µg.mL-1 (Group I); racemic bupivacaine 5 µg.mL-1 (Group II); atracurium 20 µg.mL-1 (Group III); atracurium 20 µg.mL-1 in a preparation previously exposed to lidocaine 20 µg.mL-1 and racemic bupivacaine 5 µg.mL-1, Groups IV and V, respectively. The following parameters were assessed: 1) Amplitude of hemi diaphragmatic response to indirect stimulation before and 60 minutes after addition of the drugs; 2) Membrane Potentials (MP) and Miniature Endplate Potentials (MEPPs). RESULTS: Lidocaine and racemic bupivacaine alone did not alter the amplitude of muscle response. With previous use of lidocaine and racemic bupivacaine, the neuromuscular blockade (%) induced by atracurium was 86.66 ± 12.48 and 100, respectively, with a significant difference (p = 0.003), in comparison to the blockade produced by atracurium alone (55.7 ± 11.22). These drugs did not alter membrane potential. Lidocaine initially increased the frequency of MEPPs, followed by blockade. With the use of bupivacaine, the blockade was progressive. CONCLUSIONS: Lidocaine and racemic bupivacaine had a presynaptic effect expressed by alterations in MEPPs, which may explain the interaction and potentiation of NMB produced by atracurium.

Influence of different local anesthetics on atracurium neuromuscular blockade on rats / Influência de diferentes anestésicos locais no bloqueio neuromuscular produzido pelo atracúrio em ratos

Abstract Introduction: The association between local anesthetics (LA) and neuromuscular blocking (NMB) drugs in clinical practice, and the possibility of interaction between these drugs has been investigated. LAs act on neuromuscular transmission in a dose-dependent manner and may potentiate the effects of NMB drugs. Objective: The aim of this study was to evaluate, in an experimental model, the effect of lidocaine and racemic bupivacaine on neuromuscular transmission and the influence on neuromuscular blockade produced by atracurium. Methods: Male Wistar rats, weighing from 250 to 300 g were used. The preparation was set up based on a technique proposed by Bülbring. Groups were formed (n = 5) according to the drug studied: lidocaine 20 µg.mL−1 (Group I); racemic bupivacaine 5 µg.mL−1 (Group II); atracurium 20 µg.mL−1 (Group III); atracurium 20 µg.mL−1 in a preparation previously exposed to lidocaine 20 µg.mL−1 and racemic bupivacaine 5 µg.mL−1, Groups IV and V, respectively. The following parameters were assessed: 1) Amplitude of hemi diaphragmatic response to indirect stimulation before and 60 minutes after addition of the drugs; 2) Membrane potentials (MP) and miniature endplate potentials (MEPPs). Results: Lidocaine and racemic bupivacaine alone did not alter the amplitude of muscle response. With previous use of lidocaine and racemic bupivacaine, the neuromuscular blockade (%) induced by atracurium was 86.66 ± 12.48 and 100, respectively, with a significant difference (p = 0.003), in comparison to the blockade produced by atracurium alone (55.7 ± 11.22). These drugs did not alter membrane potential. Lidocaine initially increased the frequency of MEPPs, followed by blockade. With the use of bupivacaine, the blockade was progressive. Conclusions: Lidocaine and racemic bupivacaine had a presynaptic effect expressed by alterations in MEPPs, which may explain the interaction and potentiation of NMB produced by atracurium.

Resumo Introdução: A associação de anestésicos locais (AL) com bloqueadores neuromusculares (BNM) na prática clínica e a possibilidade de interação entre esses fármacos têm sido investigadas. Objetivo: Avaliar, em modelo experimental, o efeito da lidocaína e da bupivacaína racêmica na transmissão neuromuscular e sua influência no bloqueio neuromuscular produzido pelo atracúrio. Método: Ratos machos da linhagem Wistar, peso entre 250 e 300 g. A preparação foi feita de acordo com a técnica proposta por Bulbring. Grupos (n = 5) de acordo com o fármaco em estudo: lidocaína 20 µg.mL-1 (Grupo I); bupivacaína racêmica 5 µg.mL-1 (Grupo II); atracúrio 20 µg.mL-1 (Grupo III); atracúrio 20 µg.mL-1 em preparação previamente exposta a lidocaína 20 µg.mL-1 e bupivacaína racêmica 5 µg.mL-1, Grupos IV e V, respectivamente. Foram avaliados: 1) A amplitude das respostas do hemidiafragma à estimulação indireta antes e 60 minutos após a adição dos fármacos; 2) Os potenciais de membrana (PM) e os potenciais de placa terminal em miniatura (PPTM). Resultados: Os AL, isoladamente, não alteraram a amplitude das respostas musculares. Com o uso prévio dos AL, o bloqueio neuromuscular (%) do atracúrio foi 86,66 ± 12,48 e 100, respectivamente, com diferença significante (p= 0,003) em relação ao produzido pelo atracúrio isoladamente (55,7 ± 11,22). Não alteraram o PM. A lidocaína inicialmente aumentou a frequência dos PPTM, seguido de bloqueio; com a bupivacaína, o bloqueio foi progressivo. Conclusão: A lidocaína e a bupivacaína racêmica apresentaram efeito pré-sináptico expresso por alterações nos PPTM, podem justificar a potencialização do bloqueio neuromuscular produzido pelo atracúrio.