Transforaminal epidural block with dexmedetomidine vs. corticosteroid in patients with chronic radicular low back pain

Aims and Chronic radicular low back pain is usually temporarily relieved by transforaminal epidural(TFE) injection of steroids; our aim was to evaluate the effect of TFE dexmedetomidine injection in comparison with steroids in patients with chronic lumbar radicular pain. Patients with 3 months of low back and leg pain due to intervertebral disc herniation were randomized to receive transforaminal epidural (TFE) injection(s) of 0.2% bupivacaine and either dexmedetomidine (1 mcg/kg) or triamcinolone (20mg). Patients, investigators and study coordinators were blinded to treatment. Primary outcome was visual analogue score (VAS) after the procedure, and functional improvement according to Oswestry disability index(ODI) after 2 weeks, 1, and 6 months. Other outcomes included serum Vitamin D, fasting blood sugar, and bone densitometry which were checked before and after the treatment with an interval of 1 month,3 days, and 6 months, respectively. Twenty-two patients were screened and enrolled; 11 received dexmedetomidine and 11 triamcinolone. Both groups showed significant improvement in pain score after the injection compared to baseline (p< 0.05). The dexmedetomidine group showed additional functional improvement at 1 and 6 months relative to triamcinolonebased upon ODI (p=0.001). Fasting blood sugar was also significantly increased in triamcinolone group in comparison with dexmedetomidine group (p=0.007).However, as target enrollment was not reached in our study, we cannot say with confidence that dexmedetomidine would surely result in better outcome in patients. Regarding side-effects, there were no serious complications. Radicular pain due to disc herniation improved rapidly with TFE injection of either dexmedetomidine or triamcinolone. Dexmedetomidine resulted in greater functional improvement, with better side effect profile. Future studies however, would probably determine if dexmedetomidine is superior to placebo and of particular use in those at risk for corticosteroid complications.