Use of dexmedetomidine for controlled hypotension in middle ear surgery: A systematic review and meta-analysis

Background:Microsurgical operations such as middle ear surgery rely heavily on visibility of the surgical field. Anesthetic techniques such as controlled hypotension have been developed to improve surgical field visibility by attempting to decrease bleeding. Many agents have been utilized to achieve controlled hypotension intraoperatively. Dexmedetomidine is a relatively newer agent which works on alpha-2 receptors to decrease sympathetic tone. This paper sought to determine the efficacy of dexmedetomidine for optimizing surgical field visibility in MES. Methods:A comprehensive search strategy was used in PubMed, SCOPUS, CINAHL, and CENTRAL through August 9, 2022 for this systematic review and meta-analysis. Inclusion criteria: adult patients undergoing middle ear surgery with dexmedetomidine used for controlled hypotension to improve surgical field visibility. Risk of bias was assessed via Cochrane RoB 2. Meta-analysis of mean difference for surgical field scores and risk ratios for positive surgical field scores were used to compare dexmedetomidine with placebo or other agents. Results:Fourteen studies were included in this review. Statistically significant mean difference was found to favor dexmedetomidine over placebo for Fromme-Boezaart surgical field scores. Statistically significant results were also demonstrated favoring dexmedetomidine over other agents in risk ratio for receiving positive surgical field scores, as well as surgeon and patient satisfaction scores. Conclusions:Controlled hypotension is an invaluable tool for surgical field visibility. Improved surgical field visibility was observed with dexmedetomidine compared with placebo and various other agents. Risk of suboptimal bleeding scores was significantly lower with dexmedetomidine. Dexmedetomidine is effective at improving surgical field visibility in middle ear surgery.