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 patient's self-reported 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 pain score were analyzed pre-procedurally and at a clinic visit 4 weeks post-procedurally. RESULTS Changes in numerical rating scale (NRS) 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 VRS {sp} 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 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. IRB Number: Cedars Sinai Medical Center Institutional Review Board Pro00031594