Marcelo Luis Abramides Torres

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.

Bupivacaine 0.25% and methylene blue spread with epidural anesthesia in dog

OBJECTIVE To evaluate the extent sensory and motor blocks produced by the epidural injection of different volumes of 0.25% bupivacaine (Bu) with methylene blue (MB), in dogs. STUDY DESIGN Prospective experimental trial. ANIMALS Twenty healthy adult mongrel dogs, weighing 9.9 +/- 1.9 kg. METHODS Dogs were randomly allocated into one of four groups that received 0.2, 0.4, 0.6 or 0.8 mL kg(-1) of an epidural solution containing 0.25% Bu and MB. Sensory block was evaluated against time by pinching the tail, hind limb interdigital web, toenail bases and the skin over the vertebral dermatomes. Motor block was assessed by ataxia, hind limb weight-bearing ability and by loss of muscle tone of the tail and pelvic limbs. Data were collected at 2, 5, 10, 15 and 30 minutes after the end of epidural injection. After the final time point, dogs were euthanatized and laminectomies were conducted to expose the extent of the dural dye staining. RESULTS The volumes 0.2, 0.4, 0.6 and 0.8 mL kg(-1) of 0.25% Bu and MB blocked a mean of 5, 14.2, 20.2 and 21 dermatomes, respectively. The extent of the sensory block increased up to a volume of 0.6 mL kg(-1). Motor block was longer-lasting and more intense than sensory block. Complete dyeing of the spinal cord with MB was achieved in some dogs at 0.4 mL kg(-1) and all dogs at 0.6 mL kg(-1). CONCLUSIONS The volume of anesthetic injected into the epidural space plays an important role in the quality of the epidural anesthesia. At 0.25%, bupivacaine provided an efficient sensory block at 0.6 mL kg(-1). CLINICAL RELEVANCE Relatively high volumes (0.6 mL kg(-1)) of 0.25%, BU and MB were needed to produce an effective sensory and motor block caudal to the umbilicus, but all spinal cord segments were reached by MB at this dose.

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.

Chronic pain after cesarean section. Influence of anesthetic/surgical technique and postoperative analgesia

BACKGROUND AND OBJECTIVES Brazil ranks second among countries with the highest rates of cesarean section in the world. Little is known about the future consequences of this procedure on maternal health. This study investigated the influence of anesthetic/surgical technique and postoperative analgesia on the onset of chronic pain after three months of cesarean section. METHOD This is a prospective randomized study of 443 patients undergoing cesarean section (elective and emergency), with different doses of hyperbaric bupivacaine 0.5% and opioids in spinal anesthesia. Patients were alocated into five groups as follow: G1 received hyperbaric bupivacaine (8 mg), sufentanil (2.5 μg), and morphine (100 μg); G2 received hyperbaric bupivacaine (10 mg), sufentanil (2.5 μg), and morphine (100 μg); G3 received hyperbaric bupivacaine (12.5 mg) and morphine (100 μg); G4 received hyperbaric bupivacaine (15 mg) and morphine (100 μg); G5 received hyperbaric bupivacaine (12.5 mg) and morphine (100 μg), without perioperative anti-inflammatory. Pain at rest and in movement were evaluated in the immediate postoperative period. Phone contact was made after three months of surgery for identification of patients with chronic pain. RESULTS The incidence of chronic pain in the groups was G1=20%; G2=13%; G3=7.1%; G4=2.2%, and G5=20.3%. Patients who reported higher pain scores in the postoperative period had a higher incidence of chronic pain (p<0.05). CONCLUSION The incidence of chronic pain decreases with higher doses of local anesthetics and use of anti-inflammatory drugs. The higher pain scores in the postoperative period were associated with chronic pain development after three months of cesarean section.

Correlation between the body mass index (BMI) of pregnant women and the development of hypotension after spinal anesthesia for cesarean section

BACKGROUND AND OBJECTIVES Very few publications correlate hypotension in obese pregnant women, and especially morbidly obese, after spinal anesthesia for cesarean section. The objective of the present study was to evaluate the incidence of hypotension according to the BMI. METHODS Forty-nine patients with pregestational BMI below 25 kg.m(-2) were included in the Eutrophia group, and 51 patients with BMI ≥ 25 kg.m(-2) were included in the Overweight group. After spinal anesthesia, blood pressure, volume of crystalloid infused, and dose of vasopressors used until delivery were recorded. A fall in systolic blood pressure below 100 mmHg or 10% reduction of the initial systolic blood pressure (SBP) was considered as hypotension and it was corrected by the administration of vasopressors. RESULTS Episodes of hypotension were fewer in the Eutrophia group (5.89 ± 0.53 vs. 7.80 ± 0.66, p = 0.027), as well as the amount of crystalloid administered (1,298 ± 413.6 mL vs. 1,539 ± 460.0 mL; p = 0.007), and use of vasopressors (5.87 ± 3.45 bolus vs. 7.70 ± 4.46 bolus; p = 0.023). As for associated diseases, we observed higher incidence of diabetes among obese pregnant women (29.41% vs. 9.76%, RR 1.60, 95%CI: 1.15-2.22, p = 0.036), however, differences in the incidence of pregnancy-induced hypertension (PIH) were not observe between both groups (overweight: 21.57%, normal weight: 12.20%, RR 1.30, 95%CI: 0.88-1.94, p = 0.28). CONCLUSIONS In the study sample, pregestational BMI ≥ 25 kg.m(-2) was a risk factor for hypotension after spinal anesthesia in patients undergoing cesarean section. The same group of patients required higher doses of vasopressors. Those results indicate that the anesthetic techniques in those patients should be improved to reduce the consequences of post-spinal anesthesia hypotension, both in pregnant women and fetuses.

Supplemental Oxygen and the Incidence of Perioperative Nausea and Vomiting in Cesarean Sections under Subarachnoid Block

BACKGROUND AND OBJECTIVES Supplemental oxygen can reduce the incidence of postoperative nausea and vomiting in patients under general anesthesia. The objective of the present study was to determine the efficacy of supplemental oxygen to reduce the incidence of perioperative nausea and vomiting in elective cesareans under subarachnoid block. METHODS After induction of standardized subarachnoid block, 94 parturients undergoing surgical delivery were randomly divided to receive 4 L.min-1 of oxygen (Group O) or medical air (Group S) under nasal cannula throughout the procedure. Patients were questioned on the development of nausea and vomiting during the surgery and in the first six and 24 hours after the procedure. RESULTS Demographic and perioperative parameters, as well as the data on the newborn, were comparable in both groups. In Group O, the incidence of nausea during the surgery, in the first 6 hours afterwards, and between 6 and 24 hours was 35%, 30%, and 19%, respectively, while in Group S, it was 35%, 30%, and 19%, respectively. In Group O, the incidence of vomiting was 9%, 11% and 6% in the corresponding periods, and in Group S, 21%, 7% and 7%, respectively. Those differences were not statistically significant. CONCLUSIONS The administration of supplemental oxygen from anesthetic induction until the end of the surgery did not reduce the incidence of intra- and postoperative nausea or vomiting in women undergoing cesarean section under subarachnoid block.

Oxigênio suplementar e incidência de náuseas e vômitos perioperatórios no parto cesariano sob anestesia subaracnoidea

JUSTIFICATIVA E OBJETIVOS: Oxigenio suplementar pode reduzir a incidencia de nauseas e vomitos pos-operatorios em pacientes submetidos a anestesia geral. O objetivo deste estudo foi testar a eficacia do oxigenio suplementar durante a cesariana eletiva sob anestesia subaracnoidea em diminuir a incidencia de nauseas e vomitos perioperatorios. METODO: Apos inducao de anestesia subaracnoidea padronizada, noventa e quatro parturientes submetidas ao parto operatorio foram distribuidas de forma aleatoria para receberem, atraves de cateter nasal tipo oculos, 4 L.min-1 de oxigenio (Grupo O) ou ar comprimido (Grupo S) ate o final do procedimento. As pacientes foram inquiridas acerca da ocorrencia de nauseas e vomitos durante a operacao e nas primeiras seis e 24 horas de pos-parto. RESULTADOS: Os dois grupos mostraram-se comparaveis quanto as variaveis demograficas, perioperatorias e quanto aos dados do recem-nascido. No Grupo O, a incidencia de nausea durante a operacao nas primeiras 6 horas de pos-operatorio e entre 6 e 24 horas de pos-operatorio foi de 35%, 20% e 13%, respectivamente, enquanto no Grupo S foi de 35%, 30% e 19%, respectivamente. A incidencia de vomito no Grupo O foi de 9%, 11% e 6% nos periodos correspondentes e no Grupo S 21%, 7% e 7%, respectivamente. Essas diferencas nao foram significativas. CONCLUSOES: Na populacao estudada, a oxigenoterapia suplementar desde a inducao da anestesia ate o termino da operacao nao reduziu a incidencia de nauseas ou vomitos intraoperatorios e pos-operatorios em mulheres submetidas ao parto cesariano sob anestesia subaracnoidea.

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.

Sevoflurane preconditioning during myocardial ischemia-reperfusion reduces infarct size and preserves autonomic control of circulation in rats

PURPOSE To investigate the myocardial ischemia-reperfusion with sevoflurane anesthetic preconditioning (APC) would present beneficial effects on autonomic and cardiac function indexes after the acute phase of a myocardial ischemia-reperfusion. METHODS Twenty Wistar rats were allocated in three groups: control (CON, n=10), myocardial infarction with sevoflurane (SEV, n=5) and infarcted without sevoflurane (INF, n=5). Myocardial ischemia (60 min) and reperfusion were performed by temporary coronary occlusion. Twenty-one days later, the systolic and diastolic function were evaluated by echocardiography; spectral analysis of the systolic arterial pressure (SAPV) and heart rate variability (HRV) were assessed. After the recording period, the infarct size (IS) was evaluated. RESULTS The INF group presented greater cardiac dysfunction and increased sympathetic modulation of the SAPV, as well as decreased alpha index and worse vagal modulation of the HRV. The SEV group exhibited attenuation of the systolic and diastolic dysfunction and preserved vagal modulation (square root of the mean squared differences of successive R-R intervals and high frequency) of HRV, as well as a smaller IS. CONCLUSION Sevoflurane preconditioning better preserved the cardiac function and autonomic modulation of the heart in post-acute myocardial infarction period.

Dor crônica pós-cesariana. Influência da técnica anestésico-cirúrgica e da analgesia pós-operatória

JUSTIFICATIVA Y OBJETIVOS: Brasil ocupa el segundo lugar entre los paises con mayores tasas de cesarea en el mundo. Poco se sabe respecto de las consecuencias futuras de ese procedimiento sobre la salud materna. Este estudio investigo la influencia de la tecnica anestesico-quirurgica y de la analgesia postoperatoria en el aparecimiento del dolor cronico despues de tres meses de hecha la cesarea. METODO: Este estudio prospectivo randomizado se hizo en 443 pacientes sometidas a cesarea (electiva y urgente), con diferentes dosis de bupivacaina al 0,5% hiperbarica y opioides en la raquianestesia. Los grupos fueron los siguientes: G1- 8 mg bupivacaina hiperbarica + 2,5 mg sufentanilo + 100 mg morfina; G2- 10 mg bupivacaina hiperbarica + 2,5 mg sulfentanilo + 100 mg morfina; G3- 12,5 mg bupivacaina hiperbarica + 100 mg morfina; G4- 15 mg bupivacaina hiperbarica + 100 mg morfina; G5- 12,5 mg bupivacaina hiperbarica + 100 mg morfina (sin anti-inflamatorio perioperatorio). Los dolores en estado de reposo y en movimiento fueron evaluados en el postoperatorio inmediato. Se realizo el contacto por telefono despues de tres meses del procedimiento quirurgico para la identificacion de las pacientes con dolor cronico. RESULTADOS: La incidencia de dolor cronico en los grupos fue la siguiente: G1 = 20%; G2 = 13%; G3 = 7,1%; G4 = 2,2% y G5 = 20,3%. Las pacientes que indicaron sentir puntajes de dolor mas elevados en el periodo postoperatorio, tuvieron una mayor incidencia de dolor cronico (p < 0,05). CONCLUSIONES: La incidencia de dolor cronico se reduce con el uso de dosis mas altas de anestesicos locales y con el uso de anti-inflamatorios no hormonales. Los puntajes mas elevados de dolor en el periodo postoperatorio estuvieron asociados con el aparecimiento de dolor cronico despues de tres meses de efectuada la cesarea.