Increased Dose of Betamethasone for Transforaminal Epidural Steroid Injections Is Not Associated with Superior Pain Outcomes at 4 Weeks

Background: Fluoroscopically guided transforaminal epidural steroid injections (FG-TFESIs) have been shown to provide both immediate and long-term improvement in patients' selfreported pain. Administration of the lowest possible dose of epidural betamethasone is desired to minimize side effects while maintaining efficacy. We hypothesize that a 3 mg or a 6 mg dose of betamethasone will demonstrate equivalent analgesic properties. Objectives: To compare the analgesic efficacy of 3 mg and a 6 mg dose of betamethasone for use in FG-TFESI. Study Design: Retrospective evaluation. Setting: Academic outpatient pain center. Methods: One hundred fifty-eight patients underwent FG-TFESI for lumbar back pain between 2012 and 2013. Depending on the date of service, a dose of 3 mg or a dose of 6 mg betamethasone was used in the single level unilateral TFESI. Opioid consumption and NRS-1111 pain score were analyzed pre-procedurally and at a clinic visit 4 weeks post-procedurally. Results: Changes in numerical rating scale (NRS-11-11) pain score (-1.21 + 2.61 vs. -0.81 + 2.40 respectively, P = 0.17) and changes in opioid consumption as measured in oral morphine equivalents (-2.94 + 16.4 mg vs. -2.93 + 14.8 mg, P = 0.17) were statistically equivalent between both groups. Intergroup sub-analysis of those with > 50% reduction in baseline NRS-11-11 pain score was not different (15.2% vs. 34%, P = 0.56), and the proportion with a VRS pain score < 3 were similar (24.5% vs. 23.8%, P = 0.92). Limitations: Potential selection bias inherent with study design. Conclusions: Reduction in NRS-11-11 pain scores and narcotic usage at 4 weeks after FG-TFESI were statistically equivalent between patients who received 3 mg or 6 mg of betamethasone, suggesting that a lower steroid dose has similar analgesic efficacy.