Efeitos da raquianestesia com bupivacaína hiperbárica 0,5 o/o na pressão arterial média em cães induzidos e mantidos com propofol Subarachnoid anesthesia effects with hiperbaric bupivacaine 0,5°/o in the mean arterial pressure of dogs induced and maintened with propofol

The purpose of this study was to evaluate lhe probable changes that occur in lhe mean arterial pressure (MAP) when hiperbaric bupivacaine 0,5%, (0,3 mg/kg) is used in the subarachnoid space of dogs. Six healthy femafe mongrel dogs, with an average weight between seven and fifteen kg and age between one and five years were used. lnitially, ali the animal were phsysicaly restrainted and a catheter was_ introduced into the cranial branch of saphenous artery by a percutaneous procedure to the first measure of the MAP. Then, the animais were pre-oxygenated with oxygen-enriched air during 5 minutes and induced with propofol (6 rng/kg IV). After the loss of protective reflexes, proceedeid the second measure of the MAP. After the endotracheal intubation, proceeded the third measure of the MAP. The animal were monitored and during the maintenance with a continuous . infusion of propofol (0,5 mg/kg/min), the MAP was measured every five and ten minutes until fifteen mi~;~utes. Following a wide · depilation and surgical scrub of the h.imbsacral area, we introduced lhe spinal needle in the L6-L7 interspace for the administration of the bupivacaine. Once the subaracnoid anesthesia was accomplished, we measured the MAP every five minutes during one hour. This study allows Usto observe that none of the patients developed hypotension.