A comparative study of dexmedetomidine versus clonidine as additives for spinal anesthesia: A meta-analysis of clinical trials.

BACKGROUND

To evaluate the efficacy of dexmedetomidine versus clonidine as adjuvants to local anesthetics in spinal anesthesia.

METHODS

We searched PubMed, Embase, Web of Science, and the Cochrane Library databases for randomized controlled trials (RCTs) comparing the effects of dexmedetomidine and clonidine when used as adjuvants to intrathecal local anesthetics.

RESULTS

A total of 10 randomized controlled trials were included in this meta-analysis. Compared with clonidine, dexmedetomidine significantly improved spinal block characteristics, including a faster onset of sensory block (standardized mean difference: -0.57, 95% confidence interval [CI]: -1.06 to -0.090; P < .05), a longer duration of sensory block (mean difference [MD] = 29.87 minutes, 95% CI: 21.89-37.86; P < .05), a longer duration of motor block (MD = 31.12 minutes, 95% CI: 14.51-47.73; P < .05), and a prolonged time to first rescue analgesia (MD = 21.86 minutes, 95% CI: 13.14-30.59; P < .05). No statistically significant differences were observed between the clonidine and dexmedetomidine groups with respect to the incidence of nausea and vomiting, bradycardia, hypotension, or shivering (P ≥ .05).

CONCLUSION

When used as an intrathecal adjuvant and compared with clonidine, dexmedetomidine yields superior spinal block characteristics, including a shorter onset time of sensory block, longer durations of both sensory and motor block, and an extended time to first rescue analgesia. No differences were detected between the 2 drugs in the incidence of nausea and vomiting, bradycardia, hypotension, and shivering.