Influência do tramadol associado à levobupicavaína epidural sobre a taxa de propofol e variáveis fisiológicas, em cadelas submetidas à mastectomia e à ovário-histerectomia / [Influence of tramadol combined with epidural levobupicavaine, on the propofol infusion rate and physiological variables, in female dogs undergoing mastectomy and ovariohysterectomy]

RESUMO

Objetivou-se avaliar os efeitos fisiológicos e sobre o consumo do propofol, relativos à anestesia epidural com levobupivacaína isolada ou associada a diferentes doses de tramadol. Para tal, 18 cadelas foram pré-tratadas com acepromazina, utilizando-se propofol para indução e manutenção anestésicas. Conforme o protocolo epidural instituído, formaram-se três grupos (n=6) tratados com levobupivacaína isolada (1,5mg/kg) (GL) ou acrescida de 2mg/kg (GLT2) ou 4mg/kg (GLT4) de tramadol, respectivamente. As fêmeas foram submetidas à mastectomia e à ovário-histerectomia (OH), registrando-se as variáveis fisiológicas nos períodos pré (TB e T0) e transanestésicos (T10 a T70), bem como a taxa mínima de propofol necessária. Houve redução da FC para o GL e o GLT4 em relação ao GLT2 (T30 a T70), detectando-se, no GL, redução da PAS e da PAD em relação ao TB. Maiores taxas de infusão do propofol foram necessárias para o GL (0,70±0,12mg/kg/min) em relação ao GLT2 (0,50±0,19mg/kg/min) e ao GLT4 (0,50±0,19mg/kg/min). Conclui-se que o tramadol potencializou o propofol, ao ofertar analgesia, independentemente da dose administrada. Todos os protocolos testados foram seguros e eficazes em cadelas submetidas à mastectomia e à OH.(AU)

ABSTRACT

The aim of this study was to evaluate the physiological and on propofol-sparing effects related to epidural anesthesia with levobupivacaine alone or combined with different doses of tramadol. For this purpose, 18 female dogs were pretreated with acepromazine, using propofol for induction and maintenance of anesthesia. Based on a previously established epidural (L7-S1) protocol, three groups (n=6) were treated with either levobupivacaine alone (1.5mg.k-1) (GL) or in association with to 2mg.kg-1 (GLT2) or 4mg.kg-1 (GLT4) of tramadol, respectively. These dogs were all undergoing mastectomy and ovariohysterectomy (OH). The physiological data were registered in the pre (TB and T0) and trans-anesthetic periods (T10 - T70), as well as the consumption of propofol. There was a reduction in the HR for GL and GLT4 in relation to GLT2 (T30 - T70) and reductions in SAP and DAP in relation to TB in the GL group. Higher continuous infusion rate of propofol were required for GL (0.70±0.12mg.kg-1.min-1) relative to GLT2 (0.50±0.19mg.kg-1.min-1) and GLT4 (0.50±0.19mg.kg-1.min-1). It was concluded that tramadol potentiated propofol, offering analgesia independently of its administered dose. All protocols tested were safe and effective in female dogs undergoing mastectomy and OH.(AU)