Intravenous versus perineural dexmedetomidine in prolongation of analgesia with regional anesthesia: a meta-analysis and systematic review

Abstract

Background and Objective. It is unclear whether perineural administration offers advantages when compared to intravenous dexmedetomidine in local anesthesia. To compare the efficacy of perineural versus intravenous dexmedetomidine as local anesthetic adjuvant, we conducted the meta analysis and systematic review. Materials and Methods. Two researchers searched MEDLINE, OVID, PubMed, Embase, Cochrane Central, Web of Science and Wanfang data for randomized controlled trials comparing the effect of intravenous versus perineural dexmedetomidine as local anesthetic adjuvant without any language restrictions. Results. We identified 14 randomized controlled trials (801 patients). The results revealed that the duration of analgesia (SMD: -1.76, 95 % CI, [-2.7, -0.83] P = 0.000, I2 = 96 %), the duration of sensory block (SMD:- 3.99, 95 % CI, [-5.88, -2.0], P = 0.000, I2 = 97.6 %), the duration of motor block (SMD: -1.6, 95 % CI, [-2.78, -0.41] P = 0.008, I 2 = 95.5 %) were significantly longer in the perineural group, when compared to systematic dexmedetomidine. The onset time of sensory block (SMD: 1.55, 95 % CI, [0.16, 2.94] P = 0.028, I2 = 96.7 %) and the onset time of motor block (SMD: 0.84, 95 % CI, [0.17, 1.5] P = 0.013, I2 = 88.3 %) were shorter in perineural group compared to intrave nous dexmedetomidine. Meanwhile, analgesic consumption in 24 hours (SMD: 0.37, 95 % CI, [0.05, 0.69] P = 0.023, I 2 = 55.6 %) and the incidence of patients of Ramsay Sedation Scale > 3 (RR: 3.8, 95 % CI, [1.45, 9.97] P = 0.000, I 2 = 26.9 %), hypotension (RR: 1.74, 95 % CI, [1.15, 2.65] P= 0.009, I2 = 32.7 %) and bradycardia (RR: 3.71, 95 % CI, [1.27, 10.86] P = 0.017, I2 = 0 %) were lower in perineural dexmedetomidine compared to the intravenous group. Conclusions. Our meta-analysis generates the evidence that perineural dexmedetomidine is a superior adminstration for prolonging the duration of analgesia. Perineural dexmedetomidine also shows the advantages in duration of sensory block and the onset time of sensory and motor block, when compared to the intravenous administration. Simultaneously, dexmedetomidine as a local anesthetic adjuvant for perineural injection may be much safer than intravenous application because of the lower incidence of patients of Ramsay Sedation Scale > 3 and lower incidence of hypotension and bradycardia.