Comparison of intravenous and perineural dexmedetomidine in prolongation of analgesia for peripheral nerve block: a meta-analysis and systematic review.

Abstract

We conducted a meta-analysis and systematic review to compare the efficacy of perineural vs. intravenous dexmedetomidine as local anesthetic adjuvant. Two researchers searched MEDLINE, OVID, PubMed, Embase, Cochrane Central, Web of Science and Wanfang data for randomized controlled trials comparing the effect of intravenous vs. perineural injection of dexmedetomidine as a local anesthetic adjuvant in prolongation of analgesia for peripheral nerve block, without any language restrictions. We identified 14 randomized controlled trials. The results revealed that the duration of analgesia [Standard mean difference (SMD): -0.55, 95% CI, (-1.05, -0.05) p=0.032, I2=85.4%] and the duration of sensory block [SMD: -2.68, 95% CI, (-4.53, -0.83) p=0.004, I2=97.3%], were significantly longer, the onset time of motor block [SMD: 0.65, 95% CI, (0.02, 1.27) p=0.043, I2=85.0%] was shorter in the perineural dexmedetomidine group, when compared with the systematic dexmedetomidine group. There was no significant difference in the duration of motor block [SMD: -0.32, 95% CI, (-1.11, -0.46) p=0.416, I2=89.8%] and the onset time of sensory block [SMD: 0.09, 95% CI, (-0.33, 0.52) p=0.668, I2=59.9%] between the two groups. Meanwhile, perineural dexmedetomidine reduced analgesic consumption in 24 hours [SMD: 0.43, 95% CI, (0.06, 0.80) p=0.022, I2=58.7%] compared with the intravenous dexmedetomidine group. Our meta-analysis currently generates the evidence that perineural dexmedetomidine administration offers advantages not only in prolonging the duration of analgesia and sensory block, but also in shortening the onset time of motor block, when compared with the intravenous administration.