Short-term results of intrathecal injection of low-dose bupivacaine in outpatients with chronic low back and lower extremity pain.

PURPOSE: To investigate the safety and efficacy of intrathecal injection as an alternative to epidural injection for analgesia. METHODS: Seventy consecutive outpatients with chronic low back and lower extremity pain received lumbar intrathecal injection of low-dose isobaric bupivacaine using a 25-gauge pencil-point needle. The patients received 0.5, 1.0, and 1.5 mg of bupivacaine at 1-week intervals to determine the optimal dose. Thereafter, they received two more weekly injections with the optimal dose. The safety and efficacy of the treatment were assessed over a 1-year period. RESULTS: No serious adverse events were encountered. The optimal dose of bupivacaine (1.0 mg in 60% of patients) alleviated pain and disability (both, p < 0.0001) and provided anesthesia below L1 (L5-T6). Motor block was negligible, and balance impairment improved relative to baseline (p < 0.0001). CONCLUSION: Intrathecal injection of low-dose bupivacaine offers a safe and effective treatment for chronic low back and lower extremity pain. TRIAL REGISTRATION: The study was approved by the Kitasato University Hospital Ethics Committee, and written informed consent was obtained from all individual participants included in the study. This trial was registered with the University Hospital Medical Information Network (UMIN000008670). These slides can be retrieved under electronic supplementary material.