Beneficial Effects of Remimazolam Compared with Dexmedetomidine as an Adjuvant in Total Intravenous Anaesthesia with Propofol and Remifentanil: A Randomised Controlled Trial

<i>Background and Objectives:</i> The study was designed to compare the propofol-sparing effect, intraoperative haemodynamic profiles, and recovery profiles during propofol-remifentanil total intravenous anaesthesia (TIVA) with remimazolam or dexmedetomidine co-administered as an adjuvant. <i>Materials and Methods:</i> After the remifentanil target concentration of 5 ng/mL had been achieved and endotracheal intubation was completed, the R group was intravenously administered 1 mg remimazolam/kg/hr, the D group was given 0.5 µg dexmedetomidine/kg/hr, and the control (C) group was given 1 mL normal saline/kg/hr. The allocated experimental drug infusion was initiated immediately after intubation and maintained until termination of the two target-controlled infusions of propofol and remifentanil. The propofol-sparing effect, intraoperative haemodynamic profiles and recovery profiles were assessed in the three groups. <i>Results:</i> The R group had the lowest requirement of propofol and the C group had the highest requirement of propofol. Haemodynamic profiles were similar among the groups. However, the total phenylephrine dose administered to maintain haemodynamic stability was significantly lower in the R group than in the D group and C group. Recovery profiles did not significantly differ between the groups. <i>Conclusions:</i> The co-administration of remimazolam or dexmedetomidine as an adjuvant in propofol-remifentanil TIVA reduced propofol requirements. While recovery profiles, including recovery times, postoperative pain, and postoperative nausea and vomiting, were similar among the groups, remimazolam was associated with a reduced phenylephrine requirement despite similar haemodynamic profiles.