EcoDopplercardiografia em coelhos: uso de midazolam e midazolam associado à cetamina

Abstract

RESUMOO uso de animais como modelos experimentais muitas vezes exige a administração de sedativos ou anestésicos, particularmente quando se trata de avaliação ecoDopplercardiográfica de coelhos. No entanto, existem poucas informações sobre os protocolos e seus efeitos nestes parâmetros. Diante deste contexto, foram utilizados 20 coelhos Nova Zelândia machos, com cinco meses e 3,2kg, distribuídos em dois grupos de 10 animais cada: G1 -maleato de midazolam associado ao cloridrato de cetamina, e G2 -maleato de midazolam. Compararam-se o efeito dos dois protocolos sob os índices funcionais do ventrículo esquerdo e os fluxos valvares, e observaram-se menores valores de frequência cardíaca e da fração de ejeção e maiores valores de diâmetro do ventrículo esquerdo na sístole, de volume sistólico final do ventrículo esquerdo e de diâmetro aórtico no grupo que recebeu apenas maleato de midazolam (G2). Concluiu-se que, o maleato de midazolam apresentou-se mais eficaz, pois causou boa sedação nos animais, permitindo a realização de ecoDopplercardiogramas de qualidade e efeitos limitados no sistema cardiovascular. Palavras-chave: coelho, avaliação ecoDoppercardiográfica, drogas sedativas ABSTRACT

Standard Strain and Strain Rate by Two-Dimensional Speckle Tracking in Agoutis (Dasyprocta prymnolopha) Anesthetized with Ketamine and Xylazine

“…The HR in this study was like the findings for agoutis anesthetized by the same protocol [42] and for pacas (Cuniculus paca), similar sized rodents, also chemically contained [48]. However, it was lower when compared to values obtained for non-anesthetized agoutis [14,15], New Zealand rabbits [41] and guinea pigs [8], smaller rodents. HR is inversely proportional to the size of the animal, being higher in smaller species [39].…”

“…The EPSS presented values lower than those found for conventional pigs, minipigs [27] and New Zealand rabbits [41] and higher than the findings for hedgehogs [6] and non-anesthetized agoutis [15]. Despite the differences, all are consistent with the literature, since for most species, including humans, the normal EPSS value is less than 1.0cm [3].…”

“…The values found for the thickness of agoutis heart walls and chambers when compared to mammals of different sizes, including wild rodents [20], unanesthetized agoutis [15], New Zealand rabbits [41], hedgehogs (Atelerix albiventris) [6] and ferrets (Mustela putorius furo) [49], confirm the positive linear correlation between body weight and heart dimensions for the various parameters evaluated.…”

“…The mean value found for left ventricular ejection fraction (EF) values was similar to standard values for minipigs [27] and lower when compared to New Zealand rabbits [41], guinea pigs and non-anesthetized agoutis [10]. This difference can be justified by the depressant effects of ketamine, which promotes early ventricular depolarization, interfering with blood pressure, heart rate and cardiac output [28,30].…”

“…Several studies have demonstrated normal echocardiographic parameters for domestic animals such as dogs, cats, horses, sheep [7,9,27], as well as wild rodents such as prairie dogs (Cynomys ludovicianus) [20], guinea pigs (Cavia porcellus) [10] and New Zealand rabbits [41]. However, although presumptive normal echocardiographic values were reported for non-anesthetized agoutis [15], this is the first study to show the measurement of these variables for chemically contained agoutis, in addition to the use of strain and strain rate by speckle tracking in the evaluation of cardiac function.…”