Comparison of Effects of Remimazolam and Midazolam plus Sevoflurane on Intraoperative Hemodynamics and Opioid Administration: A Retrospective Cohort Study.

Background: Remimazolam is an ultrashort-acting benzodiazepine that maintains stable hemodynamics during anesthesia. However, few reports have focused on hemodynamic stability and opioid use during cardiac surgery with remimazolam. We hypothesized that administration of remimazolam for induction and maintenance of anesthesia for transcatheter aortic valve implantation would maintain hemodynamics as effectively as conventional anesthetics and allow use of an appropriate dose of opioids. We compared intraoperative hemodynamics and opioid use in patients with severe aortic stenosis who received remimazolam or conventional anesthetics.

Methods: This retrospective cohort study analyzed data for patients who underwent transcatheter aortic valve implantation from October 2022 to September 2023. The 23 patients were divided into two groups: a remimazolam group and midazolam + sevoflurane group. The primary outcome was intraoperative blood pressure. The secondary outcomes were the doses of vasoconstrictors, vasodilators, and opioids used.

Results: There was no significant difference in any patient characteristic or intraoperative blood pressure between the two groups (before anesthesia: 92.0 [87.0-99.8] vs. 91.0 [86.0-107.0] mm Hg, P=0.935; 1 minute after induction of anesthesia: 91.0 [83.0-98.5] vs. 90.0 [86.3-95.3] mm Hg, P=0.843; at the start of surgery: 77.0 [70.0-79.0] vs. 82.5 [75.5-105.5] mm Hg, P=0.072; at the end of surgery: 74.0 [71.0-78.0] vs. 82.5 [75.5-90.8] mm Hg, P=0.082). The maximum rate of remifentanil administration was significantly higher in the remimazolam group (0.10 [0.10-0.20] vs. 0.10 [0.013-0.10] μg/kg/min, P=0.012).

Conclusions: Remimazolam maintained hemodynamics as effectively as midazolam + sevoflurane, even when used in combination with opioids. Remimazolam thus appears to be noninferior to midazolam + sevoflurane.