Efficacy of Nalbuphine as a Local Anesthetic Adjuvant for Brachial Plexus Block: A Systematic Review and Meta-analysis.

Nalbuphine has been increasingly used as a local anesthetic adjuvant to extend the duration of analgesia in brachial plexus block (BPB).To systematically and firstly evaluate the available evidence on the efficacy of nalbuphine as an adjuvant to local anesthetics in BPB.Systematic review and meta-analysis.Cochrane Central Register of Controlled Clinical Trials, Cochrane Database of Systematic Reviews, Medline, Embase, Scopus, Web of Science, EBSCO, PubMed, and additional databases were searched. Randomized controlled trials comparing combination of perineural nalbuphine with local anesthetics to local anesthetics alone in BPB for upper extremity surgical procedures were eligible for inclusion.Nineteen randomized controlled trials involving 1,355 patients met the inclusion criteria. Perineural use of nalbuphine prolonged the duration of analgesia in BPB (mean difference [MD], 162.5; 95% confidence interval [CI], 119.0 to 205.9; P < 0.00001; very low quality of evidence). The duration of sensory block was also extended (MD, 141.6; 95% CI, 100.3 to 182.9; P < 0.00001; very low quality of evidence). Furthermore, nalbuphine shortened the onset time of sensory block (MD, -2.6; 95% CI, -3.6 to -1.5; P < 0.00001; very low quality of evidence). There were no significant differences in side effect-related outcomes, including nausea (risk radio [RR], 1.56; 95% CI, 0.82 to 2.59; P = 0.17; moderate quality of evidence) and vomiting (RR, 1.41; 95% CI, 0.66 to 3.02; P = 0.38; moderate quality of evidence).The study was limited by substantial heterogeneity, a relatively small sample size and difference-in-differences in how outcomes of interest were described and assessed.Perineural use of nalbuphine in BPB is an effective strategy for analgesia in adult patients undergoing upper extremity surgery.