Dexmedetomidine versus clonidine as an adjuvant to local anaesthetic in brachial plexus blocks: a meta-analysis of randomised controlled trials.

OBJECTIVE

This meta-analysis aimed to compare the efficacy and safety of dexmedetomidine and clonidine as an adjuvant to local anesthetics in BPBs.

METHODS

Two investigators independently searched databases to identify all RCTs comparing the efficacy and/or safety of dexmedetomidine and clonidine as an adjuvant to local anesthetics in BPBs. All outcomes were pooled using the inverse variance method with a random-effect model. An I test was used to assess heterogeneity. The source of heterogeneity was explored through meta-regression. The quality of the evidence was assessed using the GRADE approach.

RESULTS

Out of 123 full texts assessed, 24 studies (1448 patients) were included in the analysis. As compared to clonidine, dexmedetomidine groups showed significantly longer sensory block duration (MD = 173.31; 95% CI 138.02‒208.59; I = 99%; GRADE approach evidence: high); motor block duration (MD = 158.35; 95% CI 131.55‒185.16; I = 98%; GRADE approach evidence: high), duration of analgesia (MD = 203.92; 95% CI 169.25‒238.58; I = 99%; GRADE approach evidence- high), and provided higher grade quality of block (RR = 1.97; 95% CI 1.60‒2.41; I = 0%; GRADE approach evidence: moderate). The block positioning technique (regression coefficient: 51.45, p = 0.005) was observed as a significant predictor of the heterogeneity in the case of sensory block duration. No significant difference was observed for the risk of hypotension (RR = 2.59; 95% CI 0.63‒10.66; I = %).

CONCLUSION

Moderate to high-quality evidence suggests dexmedetomidine is a more efficacious adjuvant to local anesthetic in BPBs than clonidine.