Efficacy and Safety of Dexmedetomidine as an Adjuvant in Peribulbar Anesthesia: A Systematic Review

Dexmedetomidine has emerged as an adjuvant for regional anesthesia, but its efficacy in peribulbar anesthesia remains poorly studied. The present review aims to assess the efficacy and safety of dexmedetomidine when used as an adjuvant in peribulbar anesthesia. Published scientific literature were extracted from the databases PubMed, Embase, Cochrane Library, CINAHL, and Google scholar. All the articles published through December 31, 2021, were included. Randomized controlled trials comparing the efficacy of dexmedetomidine as an adjuvant in peribulbar anesthesia with any other adjuvants or no adjuvants were included in this review. The primary outcomes of interest were onset of globe anesthesia (OGA), onset of globe akinesia (OGAK), and onset of lid akinesia (OLAK) and duration of globe anesthesia (DGA), duration of globe akinesia (DGAK), and duration of lid akinesia (DLAK). Risk of bias was assessed using the Cochrane Risk of Bias tool. Our search output yielded 107 studies. The duplicates were removed, and 56 studies were primarily screened. Twenty-two studies that met the inclusion criteria were reviewed. Dexmedetomidine was mostly compared to either normal saline, magnesium sulfate, fentanyl, or rocuronium. It was seen that OGA, OGAK, and OLAK were better with dexmedetomidine as an adjuvant as well as DGA, DGAK, and DLAK as compared to normal saline and other adjuvants. Meta-analysis could not be performed due to high methodological heterogenicity. No severe complications were associated with dexmedetomidine.