RESUMO
Background: Tetralogy of Fallot is one of the most frequent cyanotic heart diseases in our country, occupying the second place reported by the national health program 2007- 2012 and its prevalence is around 11%. Patients undergoing correction for tetralogy of Fallot are considered patients with a prolonged ischemic time and a high risk of presenting low cardiac output syndrome. Objective: To compare levosimendan with milrinone to prevent low cardiac output syndrome in patients undergoing tetralogy of Fallot correction. Material and methods: Randomized controlled open, prospective, longitudinal and comparative clinical trial. The sample size consisted of 19 patients, with a 95% confidence level. Group 1: levosimendan 0.1 mcg/kg/min from anesthetic induction. Group 2: conventional management with milrinone 0.5 mcg/kg/min. Results: When comparing the final measurements, it can be observed that the mean arterial pressure of the intervention group (levosimendan) was statistically significant (p = 0.04), both in the intraoperative measurement and in the final measurement. When comparing uresis, we found that the intervention group had a greater amount of uresis (p = 0.03). Regarding lactate, both in the intraoperative measurement (p = 0.002) and in the final measurement (p = 0.02), a lower amount was found in the intervention group. Conclusions: The results in favor of the use of levosimendan were reported, demonstrating the prevention of low cardiac output syndrome.
Introducción: la tetralogía de Fallot es una de las cardiopatías cianóticas más frecuentes de nuestro país, pues ocupa el segundo lugar reportado por el Programa Nacional de Salud 2007-2012 y su prevalencia se sitúa aproximadamente en 11%. Los pacientes sometidos a corrección de tetralogía de Fallot se consideran pacientes con un tiempo de isquemia prolongado y con riesgo alto de presentar síndrome de bajo gasto cardiaco. Objetivo: comparar levosimendán con milrinona para prevenir el síndrome de bajo gasto cardiaco en pacientes operados de corrección de tetralogía de Fallot. Material y métodos: ensayo clínico aleatorizado, controlado, abierto, prospectivo, longitudinal y comparativo. El tamaño de la muestra se estimó en 19 pacientes, con un nivel de confianza del 95%. En el grupo 1 se empleó 0.1 mcg/kg/min de levosimendán desde la inducción anestésica; en el grupo 2 se usó el manejo convencional con milrinona de 0.5 mcg/kg/min. Resultados: al comparar las mediciones finales se pudo observar que la presión arterial media del grupo de intervención (levosimendán) fue estadísticamente significativa (p = 0.04), tanto en la medición transoperatoria como en la medición final. Al comparar la uresis encontramos que el grupo con intervención tuvo mayor cantidad de uresis (p = 0.03). En cuanto al lactato, tanto en la medición transoperatoria (p = 0.002) como en la medición final (p = 0.02) se encontró una menor cantidad en el grupo de intervención. Conclusiones: se reportaron los resultados a favor del uso del levosimendán, pues se demostró que previene el síndrome de bajo gasto cardiaco.
Assuntos
Baixo Débito Cardíaco/prevenção & controle , Cardiotônicos , Piridazinas , Tetralogia de Fallot , Baixo Débito Cardíaco/tratamento farmacológico , Baixo Débito Cardíaco/etiologia , Cardiotônicos/farmacologia , Cardiotônicos/uso terapêutico , Criança , Humanos , Hidrazonas/farmacologia , Hidrazonas/uso terapêutico , Estudos Longitudinais , Milrinona/farmacologia , Milrinona/uso terapêutico , Estudos Prospectivos , Piridazinas/farmacologia , Piridazinas/uso terapêutico , Simendana/uso terapêutico , Síndrome , Tetralogia de Fallot/complicações , Tetralogia de Fallot/cirurgiaRESUMO
In this study, we investigated the relaxant action of galetin 3,6-dimethyl ether (FGAL) on rat aorta. The flavonoid relaxed both PMA and phenylephrine (Phe)-induced contractions (pD2 = 5.36 ± 0.11 and 4.17 ± 0.10, respectively), suggesting the involvement of PKC and Phe pathways or α1 adrenergic receptor blockade. FGAL inhibited and rightward shifted Phe-induced cumulative contractionresponse curves, indicating a noncompetitive antagonism of α1 adrenergic receptors. The flavonoid was more potent in relaxing 30 mM KCl- than 80 mM KCl-induced contractions (pD2 = 5.50 ± 0.22 and 4.37 ± 0.12). The vasorelaxant potency of FGAL on Phe-induced contraction was reduced in the presence of 10 mM TEA+. Furthermore, in the presence of apamin, glibenclamide, BaCl2 or 4-AP, FGAL-induced relaxation was attenuated, indicating the participation of small conductance calcium-activated K+ channels (SKCa), ATP-sensitive K+ channels (KATP), inward rectifier K+ channels (Kir) and voltage-dependent K+ channels (KV), respectively. FGAL inhibited and rightward shifted CaCl2-induced cumulative contraction-response curves in both depolarizing medium (high K+) and in the presence of verapamil and phenylephrine, suggesting inhibition of Ca2+ influx through voltage-gated calcium channels (CaV) and receptor operated channels (ROCs), respectively. Likewise, FGAL inhibited Phe-induced contractions in Ca2+-free medium, indicating inhibition of Ca2+ release from the sarcoplasmic reticulum (SR). FGAL potentiated the relaxant effect of aminophylline and sildenafil but not milrinone, suggesting the involvement of phosphodiesterase V (PDE V). Thus, the FGAL vasorelaxant mechanism involves noncompetitive antagonism of α1 adrenergic receptors, the non-selective opening of K+ channels, inhibition of Ca2+ influx through CaV or ROCs and the inhibition of intracellular Ca2+ release. Additionally, there is the involvement of cyclic nucleotide pathway, particularly through PDE V inhibition.
Assuntos
Aorta/fisiologia , Fabaceae/química , Flavonoides/farmacologia , Vasodilatação/efeitos dos fármacos , Aminofilina/farmacologia , Animais , Aorta/efeitos dos fármacos , Cloreto de Cálcio/farmacologia , Flavonoides/química , Técnicas In Vitro , Masculino , Milrinona/farmacologia , Contração Miocárdica/efeitos dos fármacos , Fenilefrina/farmacologia , Piperazinas/farmacologia , Bloqueadores dos Canais de Potássio/farmacologia , Purinas/farmacologia , Ratos Wistar , Citrato de Sildenafila , Sulfonamidas/farmacologia , Verapamil/farmacologiaRESUMO
BACKGROUND AND OBJECTIVES: Several classes of inotropic drugs with different hemodynamic effects are used in the treatment of low cardiac output in patients with diastolic dysfunction undergoing cardiac surgery. The objective of the present study was to compare the effects of dobutamine and milrinone on hemodynamic parameters and oxygen supply in this population of patients. METHODS: After approval by the Ethics Committee of the institution and signing of the informed consent, 20 patients undergoing cardiac surgery with cardiac index < 2 L*min(-1)*m(2) after anesthetic induction and placement of a pulmonary artery catheter were randomly divided to receive dobutamine 5 microg*kg(-1). min(-1) (n = 10), or milrinone 0.5 microg*kg(-1)*min(-1) (n = 10). Hemodynamic parameters were measured after anesthetic induction and after 30 and 60 minutes, and arterial and venous blood gases were measured at baseline and 60 minutes. Non-paired Student t test or two-way ANOVA for repeated measurements was used to compare the data. RESULTS: Dobutamine and milrinone promoted significant increases in cardiac index (56% and 47%) and oxygen supply (53% and 45%), and reduction in systemic (33% and 36%) and pulmonary (34% and 19%) vascular resistance, respectively. However, statistically significant differences were not observed between both drugs. CONCLUSIONS: Both inotropic drugs were similarly effective in restoring tissue blood flow and oxygen supply to adequate levels in patients with low cardiac output undergoing cardiac surgery.
Assuntos
Anestesia , Baixo Débito Cardíaco/tratamento farmacológico , Baixo Débito Cardíaco/metabolismo , Cardiotônicos/farmacologia , Dobutamina/farmacologia , Hemodinâmica/efeitos dos fármacos , Complicações Intraoperatórias/tratamento farmacológico , Milrinona/farmacologia , Oxigênio/metabolismo , Idoso , Procedimentos Cirúrgicos Cardíacos , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
JUSTIFICATIVA E OBJETIVOS: Diversas classes de fármacos inotrópicos, com efeitos hemodinâmicos diferentes, são utilizadas no tratamento do baixo débito cardíaco em pacientes com disfunção sistólica submetidos a procedimento cirúrgico cardíaco. O objetivo deste estudo foi comparar o efeito da dobutamina e da milrinona sobre a hemodinâmica e o transporte de oxigênio nessa população de pacientes. MÉTODO: Após aprovação do Comitê de Ética institucional e obtenção do consentimento escrito pós-informado, 20 pacientes submetidos à cirurgia cardíaca e com índice cardíaco < 2 L.min-1.m-2 pós-indução anestésica e instalação de cateter de artéria pulmonar foram distribuídos aleatoriamente para receber dobutamina 5 µg.kg-1.min-1 (n = 10) ou milrinona 0,5 µg.kg-1.min-1 (n = 10). Medidas hemodinâmicas foram obtidas pós-indução, 30 e 60 minutos após, e gasometrias arterial e venosa nos momentos basal e 60 minutos. Os dados foram comparados usando teste t de Student não pareado ou ANOVA de duas vias para medidas repetidas. RESULTADOS: A dobutamina e a milrinona promoveram aumentos significativos no índice cardíaco (56 por cento e 47 por cento) e no transporte de oxigênio (53 por cento e 45 por cento), redução nos índices de resistência vascular sistêmica (33 por cento e 36 por cento) e pulmonar (34 por cento e 19 por cento), respectivamente. Contudo, não foram observadas diferenças entre os fármacos. CONCLUSÕES: Ambos os fármacos inotrópicos foram igualmente efetivos em restaurar o fluxo tecidual sanguíneo e a oferta tecidual de oxigênio para valores adequados em pacientes com baixo débito cardíaco submetidos à cirurgia cardíaca.
BACKGROUND AND OBJECTIVES: Several classes of inotropic drugs with different hemodynamic effects are used in the treatment of low cardiac output in patients with diastolic dysfunction undergoing cardiac surgery. The objective of the present study was to compare the effects of dobutamine and milrinone on hemodynamic parameters and oxygen supply in this population of patients. METHODS: After approval by the Ethics Committee of the institution and signing of the informed consent, 20 patients undergoing cardiac surgery with cardiac index < 2 L.min-1.m2 after anesthetic induction and place ment of a pulmonary artery catheter were randomly divided to receive dobutamine 5 µg.kg-1. min-1 (n = 10), or milrinone 0.5 µg.kg-1.min-1 (n = 10). Hemodynamic parameters were measured after anesthetic induction and after 30 and 60 minutes, and arterial and venous blood gases were measured at baseline and 60 minutes. Non-paired Student t test or two-way ANOVA for repeated measurements was used to compare the data. RESULTS: Dobutamine and milrinone promoted significant increases in cardiac index (56 percent and 47 percent) and oxygen supply (53 percent and 45 percent), and reduction in systemic (33 percent and 36 percent) and pulmonary (34 percent and 19 percent) vascular resistance, respectively. However, statistically significant differences were not observed between both drugs. CONCLUSIONS: Both inotropic drugs were similarly effective in restoring tissue blood flow and oxygen supply to adequate levels in patients with low cardiac output undergoing cardiac surgery.
JUSTIFICATIVA Y OBJETIVOS: Diversas clases de fármacos inotrópicos con efectos hemodinámicos diferentes, se usan en el tratamiento del bajo débito cardíaco en pacientes con disfunción sistólica sometidos al procedimiento quirúrgico cardíaco. El objetivo de este estudio, fue comparar el efecto de la dobutamina y de la milrinona sobre la hemodinámica y el transporte de oxígeno en esa población de pacientes. MÉTODO: Después de la aprobación del Comité de Ética institucional y de la obtención del consentimiento informado, 20 pacientes sometidos a la cirugía cardíaca y con índice cardíaco < 2 L.min-1.m-2 postinducción anestésica e instalación de catéter de arteria pulmonar, fueron distribuidos aleatoriamente para recibir dobutamina 5 µg.kg-1. min-1 (n = 10) o milrinona 0,5 µg.kg-1.min-1 (n = 10). Medidas hemodinámicas se obtuvieron postinducción, entre 30 y 60 minutos después de las gasometrías arterial y venosa en los momentos basales y 60 minutos. Los datos se compararon usando el test t de Student no pareado o Anova de dos vías para medidas repetidas. RESULTADOS: La dobutamina y la milrinona produjeron aumentos significativos en el índice cardíaco (56 por ciento y 47 por ciento) y en el transporte de oxígeno (53 por ciento y 45 por ciento), una reducción en los índices de resistencia vascular sistémica (33 por ciento y 36 por ciento) y pulmonar (34 por ciento y 19 por ciento) respectivamente. Sin embargo, no fueron observadas diferencias entre los fármacos. CONCLUSIONES: Ambos fármacos inotrópicos fueron igualmente efectivos en la restauración del flujo tisular sanguíneo y en la oferta tisular de oxígeno para valores adecuados en pacientes con bajo débito cardíaco sometidos a la cirugía cardíaca.