Comparison of metaraminol, phenylephrine and ephedrine in prophylaxis and treatment of hypotension in cesarean section under spinal anesthesia / Avaliação comparativa entre metaraminol, fenilefrina e efedrina na profilaxia e no tratamento da hipotensão em cesarianas sob raquianestesia / Evaluación comparativa entre el metaraminol, la fenilefrina y la efedrina en la profilaxis y en el tratamiento de la hipotensión en cesáreas bajo anestesia espinal

Maternal hypotension is a common complication after spinal anesthesia for cesarean section, with deleterious effects on the fetus and mother. Among the strategies aimed at minimizing the effects of hypotension, vasopressor administration is the most efficient. The aim of this study was to compare the efficacy of phenylephrine, metaraminol, and ephedrine in the prevention and treatment of hypotension after spinal anesthesia for cesarean section. Ninety pregnant women, not in labor, undergoing cesarean section were randomized into three groups to receive a bolus followed by continuous infusion of vasopressor as follows: phenylephrine group (50 μg + 50 μg/min); metaraminol group (0.25 mg + 0.25 mg/min); ephedrine group (4 mg + 4 mg/min). Infusion dose was doubled when systolic blood pressure decreased to 80% of baseline and a bolus was given when systolic blood pressure decreased below 80%. The infusion dose was divided in half when systolic blood pressure increased to 120% and was stopped when it became higher. The incidence of hypotension, nausea and vomiting, reactive hypertension, bradycardia, tachycardia, Apgar scores, and arterial cord blood gases were assessed at the 1st and 5th minutes. There was no difference in the incidence of hypotension, bradycardia, reactive hypertension, infusion discontinuation, atropine administration or Apgar scores. Rescue boluses were higher only in the ephedrine group compared to metaraminol group. The incidence of nausea and vomiting and fetal acidosis were greater in the ephedrine group. The three drugs were effective in preventing hypotension; however, fetal effects were more frequent in the ephedrine group, although transient.

Hipotensão materna é uma complicação comum após raquianestesia em cirurgia cesariana, trazendo efeitos deletérios para o feto e a mãe. Entre as estratégias com o objetivo de minimizar os efeitos da hipotensão, a administração de vasopressores é a mais eficiente. O objetivo deste estudo foi comparar a eficácia da fenilefrina, metaraminol e efedrina na prevenção e tratamento de hipotensão após raquianestesia em cirurgia cesariana. Noventa gestantes que não estavam em trabalho de parto submetidas à cesariana eletiva foram randomizadas em três grupos para receber um bolus, seguido de infusão contínua de vasopressor da seguinte forma: Grupo Fenilefrina (50 μg + 50 μg/min); Grupo Metaraminol (0,25 mg + 0,25 mg/min); Grupo Efedrina (4 mg + 4 mg/min). A dose da infusão foi dobrada quando a pressão arterial sistólica (PAS) decresceu até 80% dos valores basais e um bolus foi dado quando a PAS decresceu para valores abaixo de 80%. A dose da infusão foi dividida ao meio quando a PAS aumentou até 120% e foi interrompida quando mais elevada. Foram analisadas as incidências de hipotensão, náuseas e vômitos, hipertensão reativa, bradicardia, taquicardia e escores de Apgar no primeiro e quinto minutos e gases de sangue arterial do cordão umbilical. Não houve diferenças nas incidências de hipotensão, bradicardia, hipertensão reativa, interrupção da infusão, administração de atropina ou escores de Apgar. A administração de bolus de resgate foram superiores apenas no Grupo Efedrina em comparação com Metaraminol. A incidência de náuseas e vômitos e acidose fetal foram superiores no Grupo Efedrina. Os três fármacos foram eficazes na prevenção de hipotensão, mas repercussões fetais foram mais frequentes no Grupo Efedrina, embora transitórias.

La hipotensión materna es una complicación común posterior a la anestesia espinal en cirugía de cesárea, lo que trae efectos perjudiciales para el feto y la madre. Entre las estrategias cuyo objetivo es minimizar los efectos de la hipotensión, la administración de vasopresores es la más eficaz. El objetivo de este estudio fue comparar la eficacia de la fenilefrina, del metaraminol y de la efedrina en la prevención y el tratamiento de la hipotensión posterior a la aplicación de la anestesia espinal en cirugía de cesárea. Noventa gestantes que no estaban de parto y sometidas a la cesárea electiva, fueron aleatorizadas en 3 grupos para recibir un bolo, seguido de infusión continua de vasopresor de la siguiente forma: grupo fenilefrina (50 μg + 50 μg/min); grupo metaraminol (0,25 mg + 0,25 mg/min); grupo efedrina (4 mg + 4 mg/min). La dosis de la infusión se duplicó cuando la presión arterial sistólica cayó al 80% de los valores basales y un bolo se administró cuando la presión arterial sistólica cayó a valores por debajo del 80%. La dosis de la infusión se dividió en 2 cuando la presión arterial sistólica aumentó alcanzando los 120% y fue interrumpida cuando se elevó. Se analizaron las incidencias de hipotensión, náuseas y vómitos, hipertensión reactiva, bradicardia, taquicardia y puntuaciones de Apgar en el primer y en el quinto minutos, y gases de sangre arterial del cordón umbilical. No hubo diferencias en las incidencias de hipotensión, bradicardia, hipertensión reactiva, interrupción de la infusión, administración de atropina o puntuaciones de Apgar. La administración de bolos de rescate fue superior solo en el grupo efedrina en comparación con el metaraminol. La incidencia de náuseas y vómitos y la acidosis fetal fueron superiores en el grupo efedrina. Los 3 fármacos fueron eficaces en la prevención de la hipotensión y las repercusiones fetales fueron más frecuentes en el grupo efedrina, aunque hayan sido transitorias.

Vasopressores em bloqueios do neuroeixo para cesariana / Vasopressors in neuraxial anesthesia at cesarean sections

Justificativa e objetivos: Os fármacos vasopressores sempre apresentaram um lugar de destaque no controle da hipotensão arterial relacionada aos bloqueios do neuroeixo em anestesia obstétrica. Este artigo tem o objetivo de discutir os diversos fármacos utilizados na prática clínica e as inúmeras estratégias descritas na literatura para a prevenção e tratamento da hipotensão arterial pós-raquianestesia para cesariana. Conteúdo: Com a popularização da raquianestesia como técnica mais utilizada em anestesia para cesariana, os vasopressores tornaram-se pedra angular para a melhoria dos resultados maternos e fetais. Várias mudanças de paradigmas se apresentam nos dias atuais, destacando-se a segurança na utilização de fármacos alfa-agonistas, particularmente a fenilefrina. A efedrina já não tem sido mais considerada a primeira escolha em anestesia obstétrica, pois pode causar redução no pH fetal. Conclusões: A administração pro-filática e/ou terapêutica de agonistas alfa-adrenérgicos mostra-se segura e eficaz para o controle da hipotensão arterial pós-raquianestesia, otimizando os resultados maternos e fetais. Portanto, sugere-se revisão de conceitos.

Justification and objectives: vasopressor drugs have always been highlighted for the control of hypotension related to neuraxial blockade in obstetrical anesthesia. This article purpose is arguing the several drugs used in the clinical practice and the countless strategies described in the literature for the prevention and treatment of arterial hypotension after spinal anesthesia for caesarian section. Content: With the popularization of spinal anesthesia as the technique most used in anesthesia for caesarian section, vasopressors became the angular stone for the improvement of the maternal and fetal outcomes. Several changes of paradigms are introduced currently, highlighting the safe use of alpha-agonist drugs, particularly phenylephrine. Ephedrine has no longer been considered the unique first choice in obstetrical anesthesia, because it may cause reduction in fetal pH. Conclusions: The alpha adrenergic prophylactic and/or therapeutic administration proved to be a safe and effective option for the hypotension control after spinal anesthesia, optimizing the maternal and fetal outcomes. Therefore, that is the time for reviewing old concepts.

Effect of dopamine and metaraminol on the renal function of patients with septic shock / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Vasoactive drugs are often necessary for reversing hypotension in patients with severe infection. The standard for evaluating effects of vasoactive drugs should not only be based on the increase of arterial blood pressure, but also on the blood flow perfusion of internal organs. The effects of dopamine and metaraminol on the renal function of the patients with septic shock were investigated retrospectively in this study.</p><p><b>METHODS</b>Ninety-eight patients with septic shock were divided into three groups according to the highest infusing rate of metaraminol, with the lightest infusing rate of (0.1 - 0.5, 0.6 - 1.0, > 1.0) microgxkg(-1)xmin(-1) in group A, B and C respectively. Urine output, mean arterial blood pressure (MAP), heart rate (HR), urine output, blood urea nitrogen (BUN), creatinine (CRE), urine albumin (U-ALB), urine beta(2)-microglubulin (Ubeta(2)-MG) and Apache III scores were recorded.</p><p><b>RESULTS</b>Before antishock therapy, hypotension, tachycardia and oliguria occurred to all the 98 patients with septic shock and CRE, BUN, U-ALB, Ubeta(2)-MG and Apache III scoring were abnormal in most cases. With the antishock therapy, MAP, HR, urine output, BUN and CRE in all patients returned gradually to normal (P < 0.05 or < 0.01 compared to those before antishock therapy). U-ALB, Ubeta(2)-MG output and Apache III scoring also reverted but remained abnormal (P < 0.01 compared to those before antishock therapy). No statistically significant differences in the changes of these indices with the time existed among the three groups (P > 0.05).</p><p><b>CONCLUSION</b>Dopamine and metaraminol when applied to the patients with septic shock could effectively maintain the circulatory stability and promote restoration of renal function.</p>

Successful management of stuttering priapism using home self-injections of the alpha-agonist metaraminol

Low-flow priapism can result in impotence if treatment is delayed, yet patients with recurrent priapism often suffer delay before therapy. We describe management of recurrent priapism using self-administered injections of intracavernosal metaraminol (AramineÖ, Merck), a long-acting vasoconstricting amine that is considered safer than epinephrine. The patient injects as often as once daily using 5-10 mg of drug. Our patient reports rapid detumescence and has not required emergency room visits since starting injections. He denies complications. Treatment of priapism using metaraminol has been suggested in the hospital setting; however, this is the first report of successful home self-administration of the drug.

Expansão volêmica em raquianestesia para cesariana: como realizá-la? / Fluid preload in obstetric patients: how to do it?

JUSTIFICATIVA E OBJETIVOS: Em pacientes não obstétricas, demonstrou-se que a expansão volêmica rápida realizada imediatamente após a injeção subaracnóidea do anestésico local era mais efetiva que a expansão volêmica lenta, realizada previamente à instalação do bloqueio para se reduzir a incidência e a gravidade da hipotensão arterial após raquianestesia. O objetivo do estudo foi comparar a incidência de hipotensão arterial e o consumo de vasopressores em gestantes submetidas à cesariana sob raquianestesia com diferentes regimes de expansão volêmica. MÉTODO: Foram avaliadas prospectivamente 60 gestantes de termo submetidas à cesariana sob raquianestesia. As pacientes receberam expansão volêmica com 10 ml.kg-1 de solução de Ringer com lactato como segue: Grupo 1 (n = 20), antes da raquianestesia através de cateter 18G; Grupo 2 (n = 20), após a raquianestesia e com cateter 18G e Grupo 3 (n = 20) após a raquianestesia com cateter 16G sob ação de pressurizador. A pressão arterial (PA) foi monitorizada a cada minuto e administrou-se 0,2 mg de metaraminol para qualquer diminuição de PA, a partir do valor de controle e 0,4 mg para diminuição > 20 por cento. A PA controle foi definida como a média de três valores sucessivos de pressão arterial sistólica obtidos antes da expansão volêmica e do bloqueio. Estudou-se a velocidade de infusão de fluidos, incidência de hipotensão arterial materna, náusea e vômito, consumo de metaraminol, índice de Apgar e pH da artéria umbilical. RESULTADOS: A velocidade de administração de fluidos foi maior no Grupo 3 do que nos Grupos 1 e 2 (201 ± 61 vs 56 ± 13 e 59 ± 21 ml.min-1, p < 0,05). Os grupos foram semelhantes em relação à incidência de hipotensão arterial, náusea, vômito, consumo de metaraminol, índice de Apgar e pH da artéria umbilical. CONCLUSÕES: A expansão volêmica, realizada antes ou após a instalação da raquianestesia, de maneira rápida ou lenta, não modifica o consumo de vasopressor, a ocorrência de hipotensão arterial mat...

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 Ringer's) 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 > 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 obstétricas, se demostró que la expansión volémica rápida realizada inmediatamente después de la inyección subaracnoidea del anestésico local era más efectiva que la expansión volémica lenta, realizada previamente a la instalación del bloqueo para reducir la incidencia y la gravedad de la hipotensión arterial después de raquianestesia. El objetivo del estudio fue comparar la incidencia de hipotensión arterial y el consumo de vasopresores en embarazadas sometidas a cesárea bajo raquianestesia con diferentes regímenes de expansión volémica. MÉTODO: Fueron evaluadas prospectivamente 60 embarazadas de término sometidas a cesárea bajo raquianestesia. Las pacientes recibieron expansión volémica con 10 ml.kg-1 de solución de Ringer con lactato como sigue: Grupo 1 (n = 20), antes de la raquianestesia a través de catéter 18G; Grupo 2 (n = 20), después de raquianestesia y con catéter 18G y Grupo 3 (n = 20) después de raquianestesia con catéter 16G bajo acción de un presurizador. La presión arterial (PA) fue monitorizada a cada minuto y se administró 0,2 mg de metaraminol para cualquier diminución de PA, a partir del valor de control y 0,4 mg para diminución > 20%. La PA control fue definida como la media de tres valores sucesivos de PAS obtenidos antes de la expansión volémica y del bloqueo. Se estudió la velocidad de infusión de fluidos, incidencia de hipotensión arterial materna, náusea y vómito, consumo de metaraminol, índice de Apgar y pH de la arteria umbilical. RESULTADOS: La velocidad de administración 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 relación a la incidencia de hipotensión arterial, náusea, vómito, consumo de metaraminol, índice de Apgar y pH de la arteria umbilical. CONCLUSIONES: La expansión volémica, realizada antes o después de la instalación de la raquianestesia, de manera rápida o lenta, no modifica el...

Functional alterations of the autonomic nervous system in Chagas' heart disease

Several independent pathological studies in experimental models and in human beings showed conspicuous autonomic denervation in Chagas' disease. In spite of the inherently complex structural organization of the autonomic nervous system, the parasympathetic and sympathetic divisions are involved, as shown by many functional studies. Hence, Chagas' disease represents a unique model of impairment of the autonomic control of the heart, in absence of the nonspecific effects of cardiac failure. An important limitation of the studies thus far carried out is the lack of a better knowledge of the molecular biology characteristics of different strains of T. cruzi. This could explain some geographical discrepancies found in the clinical behaviour of Chagas' disease, and contribute to a better understanding of its pathophysiology.

Emprego do metaraminol no bloqueio da hipotensäo produzida pelo uso da levomepromazina em cäes / The use of metaraminol bitartarate to blockade the hypotension produced by the levomepromazine HCL in dogs

Avaliou-se a possibilidade do uso do bitartarato de metaraminol, visando o bloqueio da hipotensäo produzida pelo cloridrato de levomepromazina em cäes. Foram empregados 20 cäes, machos e fêmeas, com pesos compreendidos entre 8 e 12 kg. Os animais foram divididos em dois grupos iguais (GI e GII). Aos cäes do GI foi administrada, por via intravenosa, levomepromazina na dose de 2 mg/kg, seguida, 15 minutos após, de 0,5 ml de soluçäo salina 0,9 por cento. A pressäo arterial sistólica (PAS), frequências cardíaca (FC) e respiratória (FR), temperatura retal (T) e avaliaçäo eletrocardiográfica na derivaçäo DII foram observadas antes da aplicaçäo da levomepromazina e após a mesma, em intervalos de 15 minutos durante 60 minutos. Aos cäes do GII foi aplicada a mesma metodologia, substituindo-se, porém, a soluçäo salina pelo metaraminol na dose de 0,1 mg/kg, pela via intravenosa. Os valores obtidos foram submetidos à avaliaçäo estatística pelo método de Análise de Perfil. Os resultados mostraram que o metaraminol produziu um aumento da PAS e diminuiçäo da FC, além de promover menor queda da T e melhora dos valores de FR. Näo foram observadas alteraçöes na eletrocardiografia que pudessem ser atribuídas aos fármacos empregados. Concluiu-se que o metaraminol é seguro e indicado quando se emprega a levomepromazina, em cäes

Hipotensäo arterial transoperatória em pacientes geriátricos para cirurgia oftálmica: revisäo terapêutica / Operative arterial hypotension in elderly patients for ophthalmic surgery: therapy review

Os pacientes para cirurgia oftálmica estäo situados, em grande parte, nas últimas décadas, exigindo durante anestesia geral inalatória cuidados especiais na prevençäo e imediato tratamento da hipotensäo arterial que muitas vezes sobrevém. Depois de revisarem as alteraçöes fisiológicas dos pacientes idosos säo descritas as açöes e os efeitos de alguns medicamentos que podem ser utilizados, visando manter perfusäo sangüínea adequada aos órgäos mais nobres, cérebro, coraçäo, e rins. Säo também descritas as açöes colaterais indesejáveis dos vasopressores indicados

Diagnosis of periodic peritonitis: evaluation of metaraminol provocation test and colchicine therapeutic trial

Periodic peritonitis [PP] or familial Mediterranean fever is not uncommonly seen in the UAE and diagnosis remains one of exclusion. The positive clinical response to colchicine therapy however, is believed by many authorities to confirm the diagnosis and the metaraminol provocation test has raised much interest in the diagnosis of the disease. Ten patients with a clinical diagnosis of periodic peritonitis were tested with metaraminol infusion-nine of them had their symptoms typically reproduced after the infusion, thus reinforcing the importance of this test in establishing the diagnosis when the disease is suspected. The details of the cases and a review of the literature are presented

The Effect of Propranolol on the bollk Pressure and Pulse Rate under Ether Halothane and Penthrane Anesthesia / 대한마취과학회지

In order to observe the effect on cardiovascular depression due to ether, halothane or penthrane anesthesia with pretreatment of propranolol (1mg) , change in the blood pressure and pulse rate were measured after intravenous administration of atropine(0.5mg), ephedrine(20mg) or aramine(2mg) to healthy volunteers. The results were as follos, 1) In conscious patients, intravenous administration of propranolol(1mg) caused a statistically significant decrease in pulse rate but no significant change in the blood pressure. 2) The atropine group showed that blood pressure increased by 33/23(p<0.01), 15/13(p<0.01) and 3/4(NS) mmHg, and pulse rate also increased by 20(p<0.01), 24(p<0.05), 11(p<0.05) per min. respectively during ether, halothane and penthrane anesthesia. 3) The ephedrine group showed that blood pressure decreased by 5/0(NS) during ether anesthesia, and increased by 27/17(p<0.01) and 30/15(p<0.01) mmHg during halothane and penthrane anesthesia respectively. Pulse rate decreased by 7(p<0.05) per min. during ether anesthesia but showed no significant change during halothane and Penthrane anesthesia. 4) The aramine group showed that blood pressure increased by 70/34(p<0.01), 29/19(p<0.01) and 28/19Ip<0.001) mmHg during ether, halothane and Penthrane anesthesia respectively. Pulse rate increased by 7(NS) per min. during ether anesthesia and decreased by 8(p<0.05) per min. during halothane and Penthrane anesthesia respectively. 5) The above results have shown that atropine caused effective correction of the cardiovascular depression induced by ether, halothane and Penthrane anesthesia with pretreatment of propranolol. Ephedrine showed futher depression and aramine effected elevation of the blood pressure.

The Effect of Propranolol on the Blood Pressure and Pulse Rate under Halothane Anesthesia / 대한마취과학회지

To combat the cardiovascular depression in blood pressure and palserate induced by halothane anesthesia in healthy persons after administration of propranolol(1.0mg) by the intravenous route, atropnie sulfate(0.5mg), ephedrine Hcl(20mg) and aramine(1.0mg) were administered respectively i.v. The results were as follows: 1) After i.v. administration of atropine sulfate, systolic blood pressure was elevated by 15 mmHg, diastolic blood pressure was elevated by 13mmHg, and pulse rate was increased by 24 per minute. 2) After i.v. administration of ephedrine, systolic blood pressure was elevated by 27 mmHg, diastolic blood pressure was elevated by 17mmHg, but significant pulse rate change was not observed. 3) After i.v. administration of aramine, systolic blood pressure was elevated by 29mmHg, diastolic blood pressure was elevated by 19mmHg, but pulse rate was decreased by 8 per minute. 4) As shown in the above results, in the cardiovascular depression due to halothane anesthesia after propranolol intravenous administration, blood pressure and pulse rated were corrected by treatment with atropine sulfate. Ephedrine and aramine effected elevation of the blood pressure, but not the pulse rate.

The Effect of Propranolol on the Blood Pressure and Pulse Rate during Ether Anesthesia / 대한마취과학회지

In propranolol (1. 0mg) pretreated men atropine (0.5mg), ephedrine (20mg) and aramine (2mg) were administered respectively by intravenous route under the ether anesthesia. The results were as follows. 1) Five minutes after intravenous administration of propranolol, the three groups showed decrease of pulse rates, 9, 6 and 8 per minutes respectively, but blood pressure changes were not observed. 2) After intravenous administration of atropine (0.5mg) the decreased pulse rates were increased and blood pressure was elevated. 3) After intravenous administration of ephedrine(20mg) the decreased pulse rates were decreased and lowered blood pressure was lowered further. 4) After intravenous administration of aramine(2.0mg) the lowered blood pressure was elevated, but pulse rate changes were not observed. 5) Circulatory depression due to ether anesthesia after propranolol pretreatment, was corrected by treatment with atropine and aramine, but was not corrected by ephedrine.