Comparison between bupivacaine 0.125% and ropivacaine 0.2% for epidural administration to outpatients with chronic low back pain

Epidural blocks should provide good analgesia for the treatment of chronic low back pain without any motor block to allow active physiotherapy. Epidural ropivacaine is known to produce less motor block compared to bupivacaine at anaesthetic concentrations. This prospective, randomized double blind study compares the analgesic, motor block, and haemodynamic effects of single shot epidural injections of ropivacaine 0.2% 10 mL with bupivacaine 0.125% in outpatients suffering from chronic low back pain.

Forty patients were assigned to receive either ropivacaine 0.2% (n = 20) or bupivacaine 0.125% (n = 20) within a series of eight single shot epidural blocks.

Thirty-six patients received either ropivacaine 0.2% (n = 18) or bupivacaine 0.125% (n = 18) within a series of eight single shot epidural blocks. Both groups showed no significant differences either in analgesia, or in motor blockade or haemodynamic changes. Thus ropivacaine 0.2% did not reduce the incidence of motor block (9.0% of patients with motor block Bromage scores 1, 2 or 3 in ropivacaine or bupivacaine). The combination of repeated epidural analgesia and physiotherapy reduced the median pain-scores (visual analogu scale, 0-10) from 7 (SD +/- 1.6) at the beginning of the study to 4.1 (SD +/- 1.7) at the end of the series.

Both bupivacaine 0.125% and ropivacaine 0.29% appear suitable for epidural administration to outpatients with chronic low back pain attending for epidural analgesia associated with physiotherapy (physical therapy).