Effects of Dexamethasone on Bupivacaine-Induced Peripheral Nerve Injection Injury in the Rat Sciatic Model.

The aim of this study was to investigate the effect of perineural dexamethasone against intraneural bupivacaine. Rats were divided into 9 groups with 6 animals in each group; Group 1 (Intraneural saline 600 µL-2ndday), Group 2 (Intraneural saline 600 µL-7th day), Group 3 (Intraneural saline 600 µL + perineural dexamethasone 0.5 mg/kg-2nd day), Group 4 (Intraneural saline 600 µL + perineural dexamethasone 0.5 mg/kg-7th day), Group 5 (Intraneural bupivacaine 10 mg/kg-2nd day), Group 6 (Intranueral bupivacaine 10 mg/kg-7th day), Group 7 (Intraneural bupivacaine 10 mg/kg + perineurald exam ethasone 0.5 mg/kg-2nd day), Group 8 (Intraneural bupivacaine 10 mg/kg + perineural dexamethasone 0.5 mg/kg-7th day), Group 9 (Control group). At the end of the application period, histopathological and immunohistochemical examinations were analyzed. It was observed that caspase 3 levels significantly increased in the 5th and 6th groups compared to the 1st and 2nd groups (p < 0.01). However, in the 7th and 8th groups, these levels were similar with 1st and 2nd groups. While a significant decrease in S 100 levels was detected in group 6 (p < 0.05), a significant increase occurred in Group 8 and reached the same levels as Group 2. According to histopathological evaluation, edema, vacuolization and myelin degeneration were significantly increased in groups 5 and 6 (p < 0.05). However, in the 8th group, the mentioned data showed a significant decrease and reached the same levels as group 2. As a result, perineural dexamethasone was found to have protective effects against intraneural bupivacaine induced sciatic nerve damage.