Efeitos sistêmicos, neurológicos e analgésicos da administração de meloxicam por via epidural.

Abstract

In order to evaluate the clinical and neurological changes and the analgesic effect of epidurally administrated meloxicam, this dissertation was divided into two chapters: the first, an assessment of systemic and neurotoxic effects of meloxicam epidural administration in rabbits and the second was a study of preemptive analgesia with meloxicam, administrated by epidural or intramuscular route, in cats undergoing ovariohysterectomy (OH). In the first paper, were used 12 rabbits distributed into two groups, which received saline (0.3 mL/kg) (Control Group) or meloxicam (0.2 mg/kg) (Meloxicam Group), both by epidural route. Were evaluated the heart rate (HR), respiratory rate (RR), body temperature (BT) and surface temperature at lumbosacral region and neurological alterations during the first 10 days of the experiment. Euthanasia was performed in three animals in each group on the 15th and 30th day after M0, for evaluation of possible spinal injuries. The changes observed in all evaluations were not suggestive of adverse effect of meloxicam. The lumbosacral epidural administration of meloxicam in a dose of 0.2 mg/kg and a volume of 0.3 mL/kg, does not cause significant systemic and neurotoxic effects in rabbits. In the secondstudy were used 16 cats distributed into two groups, which received meloxicam (0.2 mg/kg) intramuscularly (IM) and saline (0.1 mL/kg) by epidural route (Intramuscular Group - IMG) or saline (0.1 mL/kg) intramuscularly, and meloxicam (0.2 mg/kg) by epidural route (Epidural Group - EPG). Were measured HR, RR, BT and systolic blood pressure, as well as serum levels of cortisol and blood glucose. Postoperative pain was evaluated by multiparametric scale, assigning scores for each measured variable. The observed changes in clinical parameters apparently were not induced by meloxicam. Serum cortisol was high in both groups, including the initial assessment, but there was no difference between groups. Blood glucose was not different between groups, but significantly increased from two and 12 hours after meloxicam administration, respectively the IMG and the EPG. Pain scores in the IMG were statistically higher than the EPG12 hours after meloxicam administration. Rescue analgesia was required in two animals of IMG and one of EPG. Meloxicam epidural administration promotes better analgesia than intramuscular administration, but not entirely satisfactory, in cats subjected to OH. It follows that meloxicam can be administered by epidural route safely, but its analgesia is insufficient to surgical procedures that causes moderate pain. Key Words: anti-inflammatory, adverse effects, analgesia, cats, rabbits.