Berl Munch Tierarztl
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Berl Munch Tierarztl · Nov 1998
[Evaluation of the antinociceptive effect of systemic and epidurally applied xylazine in general anesthesia with isoflurane in dogs and the effect of atipamezole infection on postoperative analgesia].
The alpha 2-selective adrenergic agonist xylazine has a long lasting antinociceptive effect (> 4 hours) after lumbosacral injection in dogs (Rector, 1996). The present study was performed to find out if epidurally administered xylazine acts locally as well as systemically. In a clinical investigation 30 dogs anesthetized with isoflurane in oxygen (1.9 Vol.% ET) were examined before and after epidural and intramuscular injection of xylazine (0.25 mg/kg) during surgery and over a 240-minute postoperative period. ⋯ However, sufficient analgesic plasma xylazine concentrations could only be detected in group II up to 180 minutes after injection. After this time period, an analgesic effect could not be expected anyway, even without antagonization. It can be concluded that the epidural administration of xylazine offers advantages in contrast to a systemic administration, as a longer lasting analgesic effect can be observed (after the epidural application), and systemic side effects can be reversed without effecting spinal analgesia.