Neuraxial block quality of dexmedetomidine-containing regimens in orthopedic surgeries: a meta-analysis

Background: Dexmedetomidine is used as an adjuvant to local anesthetic agents in spinal anesthesia and is believed to increase quality of sensory and motor blocks. Our aim was to assess the effects of dexmedetomidine as an adjunct on block quality of spinal anesthesia in orthopedic procedures.Methodology: A systematic review of randomized control trials was conducted to assess the effect of intrathecal dexmedetomidine added to local anesthetic agents on the block quality of spinal anesthesia in orthopedic surgeries. PubMed, Google scholar, and Medline databases were searched for randomized controlled clinical trials. Studies met our inclusion criteria, if they used intrathecal 5 mu g dexmedetomidine as an additive to 2.5-3 ml (12.5-15 mg) bupivacaine or ropivacaine, and these were included in our meta-analysis.Results: Eight trials comprising 510 patients matched our inclusion criteria. Time to one sensory segment block regression (mean difference 139.72 min; 95% confidence interval (CI) 35.18-244.26; P = 0.009), two sensory segments block regression (mean difference 54.8 min; 95% CI [31.36-78.24]; P < 0.001), and Bromage score of zero (mean difference 93.66 min; 95%CI [30.20-157.12]; P = 0.004 ) were significantly prolonged in dexmedetomidine group. There were no significant differences between dexmedetomidine group and control group in duration of surgery (P = 0.33) or time till block reaches T10 dermatomal level (P = 0.30). Finally, time to reach Bromage score of III following injection was significantly shorter in dexmedetomidine group (mean difference 2.62 min; 95%CI [-5.12--0.13]; P = 0.04).Conclusion: Dexmedetomidine was found to achieve extended motor and sensory block when needed, bearing in mind higher cost and potential side effects.