Dexmedetomidine as an adjuvant to peripheral nerve block

Abstract

Introduction: Dexmedetomidine (DEX) is a multifunction drug proposed in recent years as an adjuvant for regional nerve blocks with local anesthetic (LA). Objetives: to evaluate the analgesic properties of this α-2 agonist when added to LA in different peripheral nerve block approaches (regional anesthesia), in terms of the quality of the analgesia obtained and potential associated complications. Materials and methods: Narrative review, using MeSH terms (English-Spanish), widely-known search engines, considering the last 5 years to date (among other filters), analyzing systematic reviews, meta-analysis or clinical trials comparing nerve blocks with/without perineural DEX added to long-term LA. Results: In general terms, it’s observed with this selective α-2 agonist, that the blockade latency decreases -19.16 %, increases analgesia duration + 60,79 % and motor blockade + 54,71 %; decreasing postoperative opioids – 49,54 % and LA consumption – 52,00 %, which would be explained by an intrinsic mechanism at perineural level. Its association with cardiovascular depression and sedation (both transient, reversible and without major clinical consequences) is dose-dependent, recommending 0,5-1 μg/kg perineural (maximum 100 μg). Conclusions: In terms of risk-benefit, perineural DEX improves the quality of analgesia obtained with minimal associated adverse effects.