Anti-Nociceptive, Analgesic and Pathohistological Effects of Intrathecal Dexmedetomidine and Bupivacaine in Rats

Background and Objectives: This study investigates analgesic and nociceptive effects of adding dexmedetomidine to bupivacaine neuraxial anesthesia through Tail-fl ick (TF) and Hot-plate (HP) tests and the pathohistological changes on spinal nerves and nerve roots through light microscopy. Methods: Forty anesthetized, male Sprague-Dawley rats were intrathecally catheterized. Basal values of TF and HP tests were measured before and after catheterization. Thirty-six successfully catheterized rats were assigned to four groups. Group B received 10 μg bupivacaine, Group BD3 received 10 μg bupivacaine + 3 μg dexmedetomidine, Group BD10 received 10 μg bupivacaine + 10 μg dexmedetomidine and Control group received 10 μL volume of artifi cial cerebrospinal fl uid. TF and HP tests were performed between the 5th and 300th minutes of drug administration. Twenty-four hours after administration of drugs, rats were sacrifi ced and spinal cord and nerve roots were removed for pathological investigation. Results: Baseline values of the TF and HP tests were not statistically different among the groups (6.8 ± 0.15 s). TF and HP latencies in the Control group did not change signifi cantly during th