Özet:
Objective: The aim of this study is to investigate the effects of two different doses of racemic ketamine on block times in the rat sciatic nerve block model and to determine whether ketamine leads to nerve damage. Method: Sixty-four, Sprague-Dawley female rats were included into the study. Rats were anesthetized with ether and then the sciatic nerves were exposed by lateral incision on posterior approach. A total of 7 groups were formed, including Sham and Saline (0.2 mL saline) for the first step of the study. The other groups according to the test doses were: Group B (0.1 mL 05% bupivacaine+ 0.1 mL saline); Group K1 (0.1 mL ketamine 0.5 mg kg-1+0.1 mL saline); Group K2 (0.1 mL ketamine 1 mg kg-1+0.1 mL saline); Group BK1 (0.1 mL 0.5% bupivacaine+0.1 mL ketamine 0.5 mg kg'); Group BK2 (0.1 mL 0.5% bupivacaine+0.1 mL ketamine 1 mg kg-1). An investigator blinded to the groups evaluated the durations of proprioceptive, motor, and sensorial block. After neurobehavioral examinations, the sciatic nenes were removed on 8th days, and were analysed for perineural inflammation, or nerve damage. Results: Ketamine (0.5mg kg-1) combination with bupivacaine prolonged the durations of proprioceptive, motor and sensorial block about %4l, %23, %33 rates, respectively. Ketamine (1mg kg-1) combination with bupivacaine prolonged the durations of proprioceptive, motor and sensorial block about %45, %37, %31 rates, respectively. While sole injection of ketamine to the sciatic nerve did not develop motor block, it provided a shorter proprioceptive block than other groups, and a similar duration for sensorial block. It was seen that the changes in durations of block were not dose-dependent. There were no statistical difference between groups according to neurotoxicity. Conclusion: We believe that rasemic ketamine may be a good adjuvant in terms of sciatic nerve block, however further studies are needed in terms of safety and systemic side effects in humans, in spite of the positive results of our study.