Efeitos da Infusäo Contínua do Propofol sobre a Funçäo Renal do Cäo. Estudo Comparativo com o Pentobarbital Sódico / Effects of continuous infusion of propofol on renal function in the dog. Comparative study with pentobarbital sodium

RESUMO

Little research has been done with propofol in relation to renal function. The aim of this study was to evaluate the effects of continuos infusion of propofol on renal function in dogs. Sixteen dogs, previously anesthetized with pentobarbital sodium (30mg.Kg-1) for surgical preparation, catheterism and monitoring, were studied. The dogs were mechanically ventilated with air and received alcuronium (0.2mg.Kg-1 in bolus and 0.6mg.Kg-1 - maintenance). The following parameters were studied: heart rate (HR), mean arterial pressure (MAP), central venous pressure (CVP), aortic blood flow (AoBF - by electromagnetic flowmeter installed in the ascending aortic), aortic vascular resistance index (AoVRI), renal plasma flow (ERPF - by para-aminohipurate clearance), glomerular filtration rate (GFR - by creatinine clearance), effective renal blood flow (ERBF = ERPF/1 - hematocrit), urinary volume (UV), renal vascular resistance (RVR = MAP.80/ERBF.10-3), urinary sodium excretion (UENa), fractionated sodim excretion (FENa), osmolar clearance (Cosm) and free water clearance (CH2o). These parameters were studied at 15 (M1), 30 (M2), 45 (M3) and 60 (M4) min after beginning pentobarbital sodium infusion (5mh.Kg-1.h-1). The dogs were allocated into two groups of eight animals each: G1 (control-pentobarbital sodium) and G2 (propofol). In G1, pentobarbital was given at the four times studied. G2 dogs received the same treatment as G1 dogs at M1 and M2; infusion of pentobarbital was substituted by propofol (3mg.Kg-1 bolus, followed by 12mg.Kg-1.h-1 continuous infusion) at M3 and M4. Profile Analysis was used to analyze the results statistically. In G1 (pentobarbital), there was a significant increase in RVR (M1M4). In G2 (propofol) there was only a significant increase in AoBF (M1propofol). It was observed that the continuous infusion of propofol in dogs, at the given doses, did not alter the basic variables of renalfunction and hemidynamics studied. We concluded that propofol can be one of the drugs of choice to provide base anesthesia in studies of renal function in dogs