Dexmedetomidine versus magnesium sulfate as an adjuvant to local anesthetics in spinal anesthesia: a meta-analysis of randomized controlled trials

Objective To compare the efficacy of dexmedetomidine and magnesium sulfate as an adjuvant to local anesthetics in spinal anesthesia. Methods A search of PubMed, Medline, Embase, the Cochrane Library, and Google Scholar was performed. Randomized controlled trials comparing the efficacy of dexmedetomidine and magnesium sulfate as a local anesthetic adjuvant in spinal anesthesia were identified. The primary outcome was sensory block duration. The mean difference (MD) or odds ratio along with the 95% confidence interval (CI) was used to analyze the outcomes. Results Six studies involving 360 patients were included. Intrathecal dexmedetomidine was associated with a significantly longer sensory block duration (MD = -73.62; 95% CI = -101.09 to -46.15), faster onsets of sensory blockade and motor blockade, and a longer motor block duration than intrathecal magnesium sulfate. There was no significant difference between the regarding the rates of hypotension, bradycardia, shivering, and postoperative nausea and vomiting between the groups. Conclusions Dexmedetomidine is superior to magnesium sulfate as an adjuvant to local anesthetics in spinal anesthesia because of its more rapid onset and longer duration of spinal block without significant adverse effects.