Sevoflurano e desflurano sobre o ritmo cardíaco de cães tratados com infusão contínua de doses crescentes de adrenalina
Data
2004-02-01
Autores
Nunes, Newton [UNESP]
Rezende, Márlis Langenegger de [UNESP]
Santos, Paulo Sérgio Patto dos [UNESP]
Wang, Lilia
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Federal de Santa Maria (UFSM)
Resumo
Os anestésicos inalatórios sensibilizam o miocárdio ou seu sistema de condução à ação das catecolaminas endógenas e/ou exógenas, predispondo o animal às arritmias cardíacas. Dentre os anestésicos voláteis, o sevoflurano e o desflurano são fármacos relativamente recentes e, embora sejam dotados de características relacionadas a não sensibilização do miocárdio às catecolaminas, desconhecem-se estudos que comparem suas eventuais propriedades antiarritmogênicas. Com o objetivo de estudar, comparativamente, o comportamento do ritmo cardíaco e observar eventuais bloqueios atrioventriculares em cães anestesiados pelo sevoflurano e desflurano e submetidos à infusão contínua de adrenalina, foram utilizados 20 animais adultos, os quais foram separados em dois grupos de igual número (G1 e G2). Aos cães do G1, foi administrado propofol, na dose média de 10mmg.kg-1; em seguida os animais receberam sevoflurano, a 1,5CAM. Decorridos 30 minutos do início da administração do anestésico volátil, iniciou-se a infusão de adrenalina na dose de 1mmg.kg-1.min-1. A cada 10 minutos, a dose da catecolamina foi acrescida em uma unidade, cessando-se a administração em 6mmg.kg-1.min-1. Para o G2, empregou-se a mesma metodologia, substituindo-se o sevoflurano pelo desflurano, administrado a 1,5CAM. A cada dose de adrenalina, foi feita contagem de batimentos ventriculares ectópicos, bem como a observação de bloqueios atrioventriculares. Os achados foram tratados pelos métodos estatísticos de Análise de Perfil e Kruskall-Wallis. Os resultados permitiram concluir que o desflurano minimiza de maneira mais eficiente a arritmia induzida pela adrenalina, além de reduzir a incidência de bloqueios atrioventriculares.
The volatile anesthetics increase the sensibility of the myocardium or its conduction system to the action of endogenous and/or exogenous epinephrine, predisposing the animal to cardiac arrhythmias. Among the volatile anesthetics, sevoflurane and desflurane are quite recent drugs and even though they have antiarrhythmogenic characteristics, there aren’t studies comparing these properties. The aim of this work was to study comparatively the cardiac rhythm and observe occasional atrioventricular blockages in dogs anesthetized with desflurane and sevoflurane, receiving increasing doses of epinephrine. 20 healthy adult male and female mongrel dogs were used. The animals were separated in two groups (G1 and G2). In G1, anesthesia was induced with propofol (10mmg-1.kg-1IV) and maintained with sevoflurane (1.5 MAC). Thirty minutes after the begin of volatile anesthetic administration, the epinephrine infusion was initiated at a dose of 1mmg.kg-1.min-1. At each 10 minutes the dose was increased in 1mmg.kg-1.min-1 until 6mmg.kg-1.min-1. For G2, the same methodology was used, except that sevoflurane was replaced by desflurane (1.5 MAC). At each epinephrine dose, the non-sinusal cardiac beats were counted and the occurrence of atrioventricular blockages was evaluated. The numerical data were submitted to Profile analysis and Kruskall-Wallis. The results allow to conclude that desflurane reduces in a more efficient way the arrhythmia produced by epinephrine and also the occurrence of atrioventricular blockages.
The volatile anesthetics increase the sensibility of the myocardium or its conduction system to the action of endogenous and/or exogenous epinephrine, predisposing the animal to cardiac arrhythmias. Among the volatile anesthetics, sevoflurane and desflurane are quite recent drugs and even though they have antiarrhythmogenic characteristics, there aren’t studies comparing these properties. The aim of this work was to study comparatively the cardiac rhythm and observe occasional atrioventricular blockages in dogs anesthetized with desflurane and sevoflurane, receiving increasing doses of epinephrine. 20 healthy adult male and female mongrel dogs were used. The animals were separated in two groups (G1 and G2). In G1, anesthesia was induced with propofol (10mmg-1.kg-1IV) and maintained with sevoflurane (1.5 MAC). Thirty minutes after the begin of volatile anesthetic administration, the epinephrine infusion was initiated at a dose of 1mmg.kg-1.min-1. At each 10 minutes the dose was increased in 1mmg.kg-1.min-1 until 6mmg.kg-1.min-1. For G2, the same methodology was used, except that sevoflurane was replaced by desflurane (1.5 MAC). At each epinephrine dose, the non-sinusal cardiac beats were counted and the occurrence of atrioventricular blockages was evaluated. The numerical data were submitted to Profile analysis and Kruskall-Wallis. The results allow to conclude that desflurane reduces in a more efficient way the arrhythmia produced by epinephrine and also the occurrence of atrioventricular blockages.
Descrição
Palavras-chave
Arrhythmia, epinephrine, Desflurane, Sevoflurane, Arritmia, adrenalina, desflurano, sevoflurano
Como citar
Ciência Rural. Universidade Federal de Santa Maria (UFSM), v. 34, n. 1, p. 125-130, 2004.