Epidural local anesthetic plus corticosteroid for the treatment of cervical brachial radicular pain:: Single injection versus continuous infusion

Background: Efficacy of epidural local anesthetics plus steroids for the treatment of cervicobrachial pain is uncertain. Methods: A prospective study randomized 160 patients with cervicobrachial pain resistant to conventional therapy. Patients were divided into 4 groups on the basis of the time between pain onset and treatment initiation: group A, 40 patients with pain onset 15 to 30 days; group B, 40 patients with pain from 31 to 60 days; group C, 40 patients, 61 to 180 days; and group D, 40 patients with pain > 180 days. Patients of each group were randomized to receive an epidural block with bupivacaine and methylprednisolone at intervals of 4 to 5 days (Single ii#cction) or continuous epidural bupivacame every 6, 12, or 24 hours plus methylprednisolone every 4 to 5 days (Continitos epidural). The maximum duration of treatment (9 blocks in Single injection, and 30 days in Contintios epidural) was dependent on achieving Pain Control (PC) > 80% [PC is defined by this formulae: (100) (VAS(intial), - VASfi,,.1)/VASinitia1]. Follow-up at I rilonth and 6 Months compared PC and the number of pain-free hours of sleep. Results: One hundred forty-one patients completed the study. The 4 groups had similar characteristics. At the 1-month and 6-month follow-up analysis based on the time between pain onset and treatment initiation showed that patients of group D, who received the Continuous epidural treatment, had significantly greater PC and significantly more pain-free hours of sleep compared with similar patients in Single injection. Conclusions: Therapy with continuous epidural local anesthetic and methylprednisolone provides better control of chronic cervicobrachial pain compared with Single injcction. These results are discussed with respect to the possible mechanism of