Mônica Maria Siaulys Capel Cardoso

Small doses of intrathecal morphine combined with systemic diclofenac for postoperative pain control after cesarean delivery

Postoperative pain control after cesarean delivery under spinal anesthesia is effectively obtained with morphine 0.1-0.3 mg intrathecally, although there may be dose-dependent side effects. We evaluated the quality of analgesia and the incidence of side effects with smaller doses of intrathecal morphine combined with intramuscular (IM) diclofenac. One hundred-twenty pregnant patients were allocated into six groups, which received the following treatments: Groups 1, 3, and 5 received 0.1, 0.05, and 0.025 mg of intrathecal morphine, respectively, plus 75 mg of IM diclofenac every 8 h; Groups 2, 4, and 6 received 0.1, 0.05, and 0.025 mg of intrathecal morphine, respectively, plus IM diclofenac on demand. Spinal anesthesia was performed with 15 mg of 0.5% hyperbaric bupivacaine. Pain scores and side effects were evaluated hourly for the first 24 h. Groups 1 and 2 had lower pain scores than Groups 3, 4, 5, and 6. However, only patients in Groups 2, 4, and 6 requested additional analgesics. Severe pruritus was more frequent in Groups 1 and 2. No patient experienced respiratory depression. We conclude that there is no advantage in using doses larger than 0.025 mg of intrathecal morphine if they are combined with systemic diclofenac. Implications: A multimodal approach to pain control may provide good quality analgesia while reducing drug-related side effects. In this study, a very small dose of intrathecal morphine, in association with intramuscular diclofenac, proved effective for controlling pain after cesarean delivery, with a low incidence of morphine-induced pruritus. (Anesth Analg 1998;86:538-41)

Drogas de abuso e gravidez

CONTEXTO: Embora seja um problema crescente na populacao mundial, existem poucos trabalhos publicados sobre o uso de drogas durante a gravidez. OBJETIVOS: Abordar de maneira objetiva as drogas de abuso (alcool, cocaina, maconha e tabaco) mais comumente utilizadas pelas mulheres em idade reprodutiva. METODOS: Foi realizada revisao bibliografica (MEDLINE, LILACS) dos textos mais recentes abordando o uso de drogas de abuso em mulheres em idade reprodutiva. RESULTADOS: Foram descritas as principais consequencias da utilizacao de drogas de abuso, tanto para a mae quanto para o bebe. CONCLUSOES: Trata-se de um problema de saude publica pouco discutido, devendo envolver uma equipe multidisciplinar em sua abordagem. A publicacao de mais trabalhos se faz necessaria, a fim de se estabelecer a melhor estrategia de intervencao nesta populacao.BACKGROUND: Despite the fact that it has being a growing problem worldwide, very few works and papers have been published on drug use during pregnancy. OBJECTIVES: To objectively address the most commonly abused drugs (alcohol, cocaine, marijuana, and tobacco) by women of a reproductive age. METHODS: A literature review (MEDLINE, LILACS) of the most recent papers on drug abuse by women of reproductive age was carried out. RESULTS: The primary consequences of drug abuse both for the mother and the infant are described. CONCLUSIONS: This is a little discussed major public health issue which requires the involvement of a multidisciplinary team. The publication of a greater number of papers on the problem is necessary in order to establish the best strategy for addressing intervention in this population.

Epidural pressures and spread of 2% lidocaine in the epidural space: influence of volume and speed of injection of the local anesthetic solution.

Background and Objectives. The impact of epidural pressures on the spread of epidural block is controversial. This study examined the effect of volume and speed of injection of local anesthetics on epidural pressures and the spread of anesthesia. Methods. Twenty women undergoing epidural anesthesia received a test dose of 3 mL of 2% lidocaine with epinephrine 1:200,000 over 6 seconds and subsequently the main dose of 15 mL of the solution over 30 seconds (group I) or 3 minutes (group II). Variables studied included epidural pressures and the extent and duration of thermal and sensory block. Results. Peak epidural pressure following the main dose was significantly higher in group I as compared to group II. All other epidural pressures and the extent and duration of sensory and thermal block were similar in both groups. The peak epidural pressure in group II and the pressures obtained at 3 minutes after the main dose in both groups were inversely correlated with the extent of the thermal block and directly correlated with its regression time. Conclusions. The peak epidural pressures correlated with the speed of injection of the lidocaine solution and not with its volume, whereas the remaining epidural pressures correlated with its volume and not with the speed of injection. The extent and duration of the thermal block exhibited a more consistent correlation (inverse and direct, respectively) with the epidural pressures than those of the sensory block.

Clinical evaluation of the flotrac/vigileo system for continuous cardiac output monitoring in patients undergoing regional anesthesia for elective cesarean section: a pilot study

BACKGROUND Spinal anesthesia for cesarean delivery may cause severe maternal hypotension and a decrease in cardiac output. Compared to assessment of cardiac output via a pulmonary artery catheter, the FloTrac/Vigileo system may offer a less invasive technique. The aim of this study was to evaluate cardiac output and other hemodynamic measurements made using the FloTrac/Vigileo system in patients undergoing spinal anesthesia for elective cesarean section. METHODS A prospective study enrolling 10 healthy pregnant women was performed. Hemodynamic parameters were continuously obtained at 15 main points: admission to surgery (two baseline measurements), after preload, after spinal anesthesia administration and 4 time points thereafter (4, 6, 8 and 10 min after anesthesia), at skin and uterine incision, newborn and placental delivery, oxytocin administration, end of surgery, and recovery from anesthesia. Hemodynamic therapy was guided by mean arterial pressure, and vasopressors were used as appropriate to maintain baseline values. A repeated measures ANOVA was used for data analysis. RESULTS There was a significant increase in heart rate and a decrease of stroke volume and stroke volume index up to 10 min after spinal anesthesia (P < 0.01). Importantly, stroke volume variation increased immediately after newborn delivery (P < 0.001) and returned to basal values at the end of surgery. Further hemodynamic parameters showed no significant changes over time. DISCUSSION AND CONCLUSIONS No significant hemodynamic effects, except for heart rate and stroke volume changes, were observed in pregnant women managed with preload and vasopressors when undergoing elective cesarean section and spinal anesthesia.

Expansão volêmica em raquianestesia para cesariana. Como realizá-la?

BACKGROUND AND OBJECTIVES In has been shown in non-obstetric patients, that a fast acute fluid preload immediately after spinal anesthesia was more effective than a slow preload before regional block to decrease the incidence and severity of arterial hypotension after spinal anesthesia. This study aimed at comparing the incidence of arterial hypotension and vasopressants consumption in parturients submitted to C-section under spinal anesthesia with different fluid preload regimens. METHODS Sixty term pregnant women submitted to C-section under spinal anesthesia. Patients were randomly distributed in three groups receiving acute preload (10 ml kg(-1) lactated Ringers) as follows: Group 1 (n = 20), before spinal anesthesia through 18G catheter; Group 2 (n = 20), after spinal anesthesia through 18G catheter and Group 3 (n = 20), after spinal anesthesia through 16G catheter with pressurizer. Blood pressure (BP) was monitored at 1-minute intervals until delivery and 0.2 mg bolus metaraminol was administered for any BP decrease from baseline values; 0.4 mg was administered for BP decrease >or= 20%. Control blood pressure was defined as the mean of three successive SBP values obtained before acute preload and spinal block. Variables studied were: preload rate, incidence of maternal arterial hypotension, nausea, vomiting, vasopressants consumption, Apgar scores and umbilical artery pH. RESULTS Acute preload was faster in Group 3 as compared to Groups 1 and 2 (201 +/- 61 vs 56 +/- 13 and 59 +/- 21 ml min(-1), p < 0.05). Groups were similar regarding the incidence of arterial hypotension, nausea and vomiting, metaraminol consumption, Apgar scores and umbilical artery pH. CONCLUSIONS Acute preload before or after spinal anesthesia performance, in a slow or fast rate, does not change vasopressants consumption, the incidence of maternal arterial hypotension, nausea and vomiting, as well as fetal wellbeing.JUSTIFICATIVA Y OBJETIVOS: En pacientes no obstetricas, se demostro que la expansion volemica rapida realizada inmediatamente despues de la inyeccion subaracnoidea del anestesico local era mas efectiva que la expansion volemica lenta, realizada previamente a la instalacion del bloqueo para reducir la incidencia y la gravedad de la hipotension arterial despues de raquianestesia. El objetivo del estudio fue comparar la incidencia de hipotension arterial y el consumo de vasopresores en embarazadas sometidas a cesarea bajo raquianestesia con diferentes regimenes de expansion volemica. METODO: Fueron evaluadas prospectivamente 60 embarazadas de termino sometidas a cesarea bajo raquianestesia. Las pacientes recibieron expansion volemica con 10 ml.kg-1 de solucion de Ringer con lactato como sigue: Grupo 1 (n = 20), antes de la raquianestesia a traves de cateter 18G; Grupo 2 (n = 20), despues de raquianestesia y con cateter 18G y Grupo 3 (n = 20) despues de raquianestesia con cateter 16G bajo accion de un presurizador. La presion arterial (PA) fue monitorizada a cada minuto y se administro 0,2 mg de metaraminol para cualquier diminucion de PA, a partir del valor de control y 0,4 mg para diminucion > 20%. La PA control fue definida como la media de tres valores sucesivos de PAS obtenidos antes de la expansion volemica y del bloqueo. Se estudio la velocidad de infusion de fluidos, incidencia de hipotension arterial materna, nausea y vomito, consumo de metaraminol, indice de Apgar y pH de la arteria umbilical. RESULTADOS: La velocidad de administracion de fluidos fue mayor en el Grupo 3 de que en los Grupos 1 y 2 (201 ± 61 vs 56 ± 13 y 59 ± 21 ml.min-1, p < 0,05). Los grupos fueron semejantes en relacion a la incidencia de hipotension arterial, nausea, vomito, consumo de metaraminol, indice de Apgar y pH de la arteria umbilical. CONCLUSIONES: La expansion volemica, realizada antes o despues de la instalacion de la raquianestesia, de manera rapida o lenta, no modifica el consumo de vasopresor, la ocurrencia de hipotension arterial materna, nausea o vomitos, y tampoco el bien estar fetal.

Sufentanil subaracnóideo associado à bupivacaína hiperbárica para analgesia de parto: É possível reduzir a dose do opióide?

BACKGROUND AND OBJECTIVES The association of isobaric bupivacaine to lower spinal sufentanil dose provides satisfactory analgesia and lower incidence of side effects. This study aimed at evaluating quality of analgesia and incidence of side effects of decreased spinal sufentanil doses associated to hyperbaric bupivacaine for labor analgesia. METHODS Participated in this study 69 healthy term pregnant patients in active labor. Patients were randomly allocated in three groups receiving spinal combination of 2.5 mg hyperbaric bupivacaine and 1 mL saline solution (Control Group); 2.5 mg hyperbaric bupivacaine and 2.5 microg sufentanil (S2.5 Group) or 2.5 mg hyperbaric bupivacaine and 5 microg sufentanil (S5 Group). Pain, using a visual analogue scale (VAS), and side effects were evaluated at 5-minute intervals for the first 15 minutes and then at 15-minute interval until delivery. Study would end with delivery or when patient requested rescue analgesia (VAS > 3 cm). RESULTS Groups S2.5 and S5 presented longer analgesia duration (67.2 +/- 38.6 and 78.9 +/- 38.7 minutes, respectively) and a larger number of patients with effective analgesia (100% and 95.6%, respectively) as compared to Control group where mean analgesia duration was 35.9 +/- 21.6 minutes (p < 0.05) with 69.6% of patients with effective analgesia (p < 0.05). CONCLUSIONS The association of sufentanil to hyperbaric bupivacaine improves quality and prolongs analgesia duration. When associated to 2.5 mg hyperbaric bupivacaine, there is no benefit in administering more than 2.5 microg of sufentanil for labor pain relief.JUSTIFICATIVA Y OBJETIVOS: La adicion de bupivacaina isobarica a dosis menores de sufentanil por via subaracnoidea promueve analgesia de cualidad satisfactoria, con menor incidencia de efectos colaterales. El objetivo del estudio fue evaluar la calidad de la analgesia y la incidencia de efectos colaterales de dosis reducidas de sufentanil subaracnoideo asociados a bupivacaina hiperbarica en analgesia de parto. METODO: Fueron estudiadas prospectivamente 69 embarazadas de termino en trabajo de parto. Las embarazadas fueron aleatoriamente divididas en tres grupos que recibieron, en el espacio subaracnoideo, la combinacion de 2,5 mg de bupivacaina hiperbarica y 1 mL de solucion fisiologica (Grupo Control); 2,5 mg de bupivacaina hiperbarica y 2,5 µg de sufentanil (Grupo S2,5) o 2,5 mg de bupivacaina hiperbarica y 5 µg de sufentanil (Grupo S5). El dolor, de acuerdo con la escala analogico visual (EAV) de dolor y la incidencia de efectos colaterales fueron evaluadas a cada 5 minutos en los primeros quince minutos y a seguir a cada 15 minutos hasta el nacimiento. El estudio terminaba con el nacimiento, o cuando la paciente solicitaba medicacion analgesica de rescate (EAV > 3 cm). RESULTADOS: Los grupos S2,5 y S5 presentaron mayor duracion de analgesia (67,2 ± 38,6 y 78,9 ± 38,7 minutos, respectivamente) y mayor porcentaje de pacientes con analgesia efectiva (100% y 95,6%, respectivamente) que el grupo Control, en el cual la duracion media de analgesia fue de 35,9 ± 21,6 minutos (p < 0,05) y el porcentaje de pacientes con analgesia efectiva fue de 69,6% (p < 0,05). CONCLUSIONES: La adicion de sufentanil a la bupivacaina hiperbarica mejora la calidad y prolonga la duracion de la analgesia. Cuando asociado a 2,5 mg de bupivacaina hiperbarica, no hay ventaja de administrar dosis superior a 2,5 µg de sufentanil para alivio del dolor del trabajo de parto.

Efeito da adição de clonidina subaracnóidea à solução anestésica de sufentanil e bupivacaína hiperbárica ou hipobárica para analgesia de parto

JUSTIFICATIVA Y OBJETIVOS: La adicion de la clonidina subaracnoidea (±-agonista), prolonga la accion analgesica de la combinacion sufentanil y bupivacaina isobarica en analgesia combinada para el trabajo de parto 1. El objetivo de este estudio fue comparar la calidad de analgesia y la prevalencia de los efectos colaterales, despues de la adicion de clonidina subaracnoidea a la solucion anestesica en gestantes durante el parto. METODO: Despues de la aprobacion de la Comision de Etica, 22 gestantes en trabajo de parto recibieron aleatoriamente en el espacio subaracnoideo 2,5 mg de bupivacaina hiperbarica 0,5% (grupo CLON/HIPER; n = 11) o 2,5 mg de bupivacaina isobarica 0,5% (grupo CLON/ISO; n = 11) en asociacion con el sufentanil 2,5 µg y la clonidina 30 µg. El dolor evaluado por la Escala Analogica Visual, la frecuencia cardiaca y la presion arterial promedio, fueron estudiados a cada 5 minutos en los primeros 15 minutos y a continuacion, a cada 15 minutos hasta el nacimiento. Fue evaluada la prevalencia de efectos colaterales (nausea, vomito, prurito y sedacion). El estudio fue terminado en el momento en que se hizo necesaria la complementacion analgesica epidural (dolor > 3 cm) o al nacimiento. El analisis estadistico fue realizado a traves de los tests t de Student, Chi-cuadrado, Fisher y ANOVA de dos vias para medidas repetidas, considerando como significativo p < 0,05. RESULTADOS: Los grupos CLON/HIPER y CLON/ISO fueron similares con relacion a los datos antropometricos, duracion de la analgesia (70,9 ± 32,9 vs. 85,4 ± 39,5), frecuencia cardiaca, incidencia de prurito, sedacion, nausea y vomitos. En el grupo CLON/ISO hubo una disminucion significativa de la presion arterial promedio con relacion al grupo CLON/HIPER en los momentos 15, 30, y 45 minutos (p < 0,05). CONCLUSIONES: En las condiciones estudiadas, la adicion de clonidina en baja dosis (30 ¼g), asociada al sufentanil, determino una mayor incidencia de hipotension cuando se administro con soluciones isobaricas de anestesico local. Con relacion a los demas efectos colaterales, las soluciones hiperbaricas e isobaricas se comportan de manera similar.BACKGROUND AND OBJECTIVES The addition of subarachnoid clonidine (alpha-agonist) prolongs the analgesia produced by the combination of sufentanil and isobaric bupivacaine in combined labor analgesia(1). The objective of this study was to compare the quality of analgesia and the prevalence of side effects after the addition of subarachnoid clonidine to the anesthetic solution in labor analgesia. METHODS After approval by the Ethics Commission, 22 pregnant women in labor were randomly assigned to the subarachnoid administration of either 2.5 mg of 0.5% hyperbaric bupivacaine (CLON/HYPER Group; n = 11) or 2.5 mg of 0.5% isobaric bupivacaine (CLON/ISO Group; n = 11) associated with 2.5 microg of sufentanil and 30 microg of clonidine. Pain, evaluated by the Visual Analogue Scale, heart rate, and mean arterial pressure were assessed every 5 minutes during the first 15 minutes, and then every 15 minutes afterwards until delivery. The prevalence of side effects (nausea, vomiting, pruritus, and sedation) was evaluated. The study was terminated whenever the patient needed supplemental epidural analgesia (pain > 3) or upon delivery of the fetus. The Student t test, Chi-square test, Fisher exact test, and two-way ANOVA for repeated measurements were used in the statistical analysis and a p < 0.05 was considered significant. RESULTS Anthropometric data, duration of analgesia (70.9 +/- 32.9 vs. 85.4 +/- 39.5), heart rate, and the incidence of pruritus, sedation, nausea, and vomiting were similar in both groups. Mean arterial pressure was significantly lower in the CLON/ISO Group than in the CLON/HYPER Group at 15, 30, and 45 minutes (p < 0.05). CONCLUSIONS Under the conditions of the present study, the association of a small dose of clonidine (30 microg) with sufentanil caused a higher incidence of hypotension when the isobaric solution of the local anesthetic was used. For all other side effects, both hyperbaric and isobaric solutions showed similar behavior.

Ocitocina em cesarianas: qual a Melhor Maneira de Utilizá-la?

BACKGROUND AND OBJECTIVES Oxytocin is the uterotonic used in obstetric anesthesia, and its prophylactic and therapeutic administration is justified because it reduces the incidence of post-partum hemorrhage. However, the ideal infusion regimen in elective cesarean sections has not been determined yet. The objective of this study was to review the main physiological and pharmacological characteristics of oxytocin and to discuss its rational use by anesthesiologists in view of its side effects. CONTENTS Oxytocin is produced by the hypothalamus and stored in the posterior lobe of the pituitary gland. In the uterus, is causes contraction of the smooth muscle, which is very important to control hemorrhage after uterine emptying. It also affects other systems, and the reduction in peripheral vascular resistance with consequent hypotension is very important. The extra-uterine actions of oxytocin are important when administered in high doses or in bolus, especially in parturients under anesthesia (spinal block or general anesthesia) with hypovolemia or preexistent alterations in the cardiovascular system. Several infusion regimens have been studied, varying the dose and/or the speed of administration, in an attempt to establish the most adequate. CONCLUSIONS Due to its wide therapeutic spectrum, oxytocin remains the drug of choice to prevent uterine atony after cesarean sections. Although it has been used for almost 50 years, the adequate infusion regimen in cesarean sections has not been determined yet. The current tendency is to use continual infusion of low doses, and bolus administration should be avoided.JUSTIFICATIVA Y OBJETIVOS: La ocitocina es un uterotonico utilizado en anestesia obstetrica, cuya administracion, tanto profilactica, como terapeutica, se justifica por reducir la incidencia de hemorragia despues del alumbramiento. Sin embargo, todavia no se establecio el regimen ideal de infusion en cesareas electivas. Este estudio tiene la intencion de revisar las principales caracteristicas fisiologicas y farmacologicas de la ocitocina y discutir su uso racional por parte de los anestesiologos, teniendo en cuenta sus efectos colaterales. CONTENIDO: La ocitocina es producida por el hipotalamo y almacenada por la hipofisis posterior. En el utero, hay una contraccion de la musculatura lisa que es bastante importante para el control de la hemorragia despues de la expulsion de la placenta. Actua tambien en otros sistemas, siendo relevante la reduccion de la resistencia vascular periferica con la consecuente hipotension arterial. Las acciones extra-uterinas pasan a ser importantes cuando la ocitocina se crea en altas dosis o en bolus, especialmente en embarazadas bajo anestesia (sea bloqueo espinal o anestesia general) presentando hipovolemia, o con alteracion previa en el sistema cardiovascular. Diversos regimenes de infusion han sido estudiados, variando la dosis y/o la velocidad de infusion en la tentativa de establecer cual es la manera mas adecuada para su utilizacion. CONCLUSIONES: La ocitocina permanece como farmaco de primera eleccion para la prevencion y el tratamiento de la atonia uterina despues de la cesarea, especialmente por su amplio espectro terapeutico. A pesar de estar disponible para la practica clinica hace casi 50 anos, todavia no esta establecido cual es el regimen adecuado de su infusion en cesareas. La tendencia actual es la utilizacion en infusion continua de dosis reducidas, debiendo ser evitada la administracion en bolus.

Fluid preload in obstetric patients. How to do it

BACKGROUND AND OBJECTIVES In has been shown in non-obstetric patients, that a fast acute fluid preload immediately after spinal anesthesia was more effective than a slow preload before regional block to decrease the incidence and severity of arterial hypotension after spinal anesthesia. This study aimed at comparing the incidence of arterial hypotension and vasopressants consumption in parturients submitted to C-section under spinal anesthesia with different fluid preload regimens. METHODS Sixty term pregnant women submitted to C-section under spinal anesthesia. Patients were randomly distributed in three groups receiving acute preload (10 ml kg(-1) lactated Ringers) as follows: Group 1 (n = 20), before spinal anesthesia through 18G catheter; Group 2 (n = 20), after spinal anesthesia through 18G catheter and Group 3 (n = 20), after spinal anesthesia through 16G catheter with pressurizer. Blood pressure (BP) was monitored at 1-minute intervals until delivery and 0.2 mg bolus metaraminol was administered for any BP decrease from baseline values; 0.4 mg was administered for BP decrease >or= 20%. Control blood pressure was defined as the mean of three successive SBP values obtained before acute preload and spinal block. Variables studied were: preload rate, incidence of maternal arterial hypotension, nausea, vomiting, vasopressants consumption, Apgar scores and umbilical artery pH. RESULTS Acute preload was faster in Group 3 as compared to Groups 1 and 2 (201 +/- 61 vs 56 +/- 13 and 59 +/- 21 ml min(-1), p < 0.05). Groups were similar regarding the incidence of arterial hypotension, nausea and vomiting, metaraminol consumption, Apgar scores and umbilical artery pH. CONCLUSIONS Acute preload before or after spinal anesthesia performance, in a slow or fast rate, does not change vasopressants consumption, the incidence of maternal arterial hypotension, nausea and vomiting, as well as fetal wellbeing.JUSTIFICATIVA Y OBJETIVOS: En pacientes no obstetricas, se demostro que la expansion volemica rapida realizada inmediatamente despues de la inyeccion subaracnoidea del anestesico local era mas efectiva que la expansion volemica lenta, realizada previamente a la instalacion del bloqueo para reducir la incidencia y la gravedad de la hipotension arterial despues de raquianestesia. El objetivo del estudio fue comparar la incidencia de hipotension arterial y el consumo de vasopresores en embarazadas sometidas a cesarea bajo raquianestesia con diferentes regimenes de expansion volemica. METODO: Fueron evaluadas prospectivamente 60 embarazadas de termino sometidas a cesarea bajo raquianestesia. Las pacientes recibieron expansion volemica con 10 ml.kg-1 de solucion de Ringer con lactato como sigue: Grupo 1 (n = 20), antes de la raquianestesia a traves de cateter 18G; Grupo 2 (n = 20), despues de raquianestesia y con cateter 18G y Grupo 3 (n = 20) despues de raquianestesia con cateter 16G bajo accion de un presurizador. La presion arterial (PA) fue monitorizada a cada minuto y se administro 0,2 mg de metaraminol para cualquier diminucion de PA, a partir del valor de control y 0,4 mg para diminucion > 20%. La PA control fue definida como la media de tres valores sucesivos de PAS obtenidos antes de la expansion volemica y del bloqueo. Se estudio la velocidad de infusion de fluidos, incidencia de hipotension arterial materna, nausea y vomito, consumo de metaraminol, indice de Apgar y pH de la arteria umbilical. RESULTADOS: La velocidad de administracion de fluidos fue mayor en el Grupo 3 de que en los Grupos 1 y 2 (201 ± 61 vs 56 ± 13 y 59 ± 21 ml.min-1, p < 0,05). Los grupos fueron semejantes en relacion a la incidencia de hipotension arterial, nausea, vomito, consumo de metaraminol, indice de Apgar y pH de la arteria umbilical. CONCLUSIONES: La expansion volemica, realizada antes o despues de la instalacion de la raquianestesia, de manera rapida o lenta, no modifica el consumo de vasopresor, la ocurrencia de hipotension arterial materna, nausea o vomitos, y tampoco el bien estar fetal.

Effects of the addition of subarachnoid clonidine to the anesthetic solution of sufentanil and hyperbaric or hypobaric bupivacaine for labor analgesia

JUSTIFICATIVA Y OBJETIVOS: La adicion de la clonidina subaracnoidea (±-agonista), prolonga la accion analgesica de la combinacion sufentanil y bupivacaina isobarica en analgesia combinada para el trabajo de parto 1. El objetivo de este estudio fue comparar la calidad de analgesia y la prevalencia de los efectos colaterales, despues de la adicion de clonidina subaracnoidea a la solucion anestesica en gestantes durante el parto. METODO: Despues de la aprobacion de la Comision de Etica, 22 gestantes en trabajo de parto recibieron aleatoriamente en el espacio subaracnoideo 2,5 mg de bupivacaina hiperbarica 0,5% (grupo CLON/HIPER; n = 11) o 2,5 mg de bupivacaina isobarica 0,5% (grupo CLON/ISO; n = 11) en asociacion con el sufentanil 2,5 µg y la clonidina 30 µg. El dolor evaluado por la Escala Analogica Visual, la frecuencia cardiaca y la presion arterial promedio, fueron estudiados a cada 5 minutos en los primeros 15 minutos y a continuacion, a cada 15 minutos hasta el nacimiento. Fue evaluada la prevalencia de efectos colaterales (nausea, vomito, prurito y sedacion). El estudio fue terminado en el momento en que se hizo necesaria la complementacion analgesica epidural (dolor > 3 cm) o al nacimiento. El analisis estadistico fue realizado a traves de los tests t de Student, Chi-cuadrado, Fisher y ANOVA de dos vias para medidas repetidas, considerando como significativo p < 0,05. RESULTADOS: Los grupos CLON/HIPER y CLON/ISO fueron similares con relacion a los datos antropometricos, duracion de la analgesia (70,9 ± 32,9 vs. 85,4 ± 39,5), frecuencia cardiaca, incidencia de prurito, sedacion, nausea y vomitos. En el grupo CLON/ISO hubo una disminucion significativa de la presion arterial promedio con relacion al grupo CLON/HIPER en los momentos 15, 30, y 45 minutos (p < 0,05). CONCLUSIONES: En las condiciones estudiadas, la adicion de clonidina en baja dosis (30 ¼g), asociada al sufentanil, determino una mayor incidencia de hipotension cuando se administro con soluciones isobaricas de anestesico local. Con relacion a los demas efectos colaterales, las soluciones hiperbaricas e isobaricas se comportan de manera similar.BACKGROUND AND OBJECTIVES The addition of subarachnoid clonidine (alpha-agonist) prolongs the analgesia produced by the combination of sufentanil and isobaric bupivacaine in combined labor analgesia(1). The objective of this study was to compare the quality of analgesia and the prevalence of side effects after the addition of subarachnoid clonidine to the anesthetic solution in labor analgesia. METHODS After approval by the Ethics Commission, 22 pregnant women in labor were randomly assigned to the subarachnoid administration of either 2.5 mg of 0.5% hyperbaric bupivacaine (CLON/HYPER Group; n = 11) or 2.5 mg of 0.5% isobaric bupivacaine (CLON/ISO Group; n = 11) associated with 2.5 microg of sufentanil and 30 microg of clonidine. Pain, evaluated by the Visual Analogue Scale, heart rate, and mean arterial pressure were assessed every 5 minutes during the first 15 minutes, and then every 15 minutes afterwards until delivery. The prevalence of side effects (nausea, vomiting, pruritus, and sedation) was evaluated. The study was terminated whenever the patient needed supplemental epidural analgesia (pain > 3) or upon delivery of the fetus. The Student t test, Chi-square test, Fisher exact test, and two-way ANOVA for repeated measurements were used in the statistical analysis and a p < 0.05 was considered significant. RESULTS Anthropometric data, duration of analgesia (70.9 +/- 32.9 vs. 85.4 +/- 39.5), heart rate, and the incidence of pruritus, sedation, nausea, and vomiting were similar in both groups. Mean arterial pressure was significantly lower in the CLON/ISO Group than in the CLON/HYPER Group at 15, 30, and 45 minutes (p < 0.05). CONCLUSIONS Under the conditions of the present study, the association of a small dose of clonidine (30 microg) with sufentanil caused a higher incidence of hypotension when the isobaric solution of the local anesthetic was used. For all other side effects, both hyperbaric and isobaric solutions showed similar behavior.