Methods
Fifty patients were assigned to two groups. The 20 ml group received ESB with 10 ml of bupivacaine 0.5%, 1 ml of 40 mg/ml of methylprednisolone, 2 ml of non-ionic contrast, and 7 ml of saline 0.9%. The 30 ml group received ESB with 15 ml of bupivacaine 0.5%, 1 ml of 40 mg/ml of methylprednisolone, 2 ml of non-ionic contrast, and 12 ml of saline 0.9%.