Interaction Between Remimazolam and Propofol of Target-Controlled Infusion During General Anesthesia Induction

Objective: To investigate the interaction between target-controlled infusion (TCI) of remimazolam besylate and propofol during combined induction, focusing on sedation and blood pressure effects. Methods: Patients scheduled for elective surgery under general anesthesia (aged 35–55 years, ASA I or II) were enrolled from the Third Clinical Medical College of Xinjiang Medical University between June to July 2024. Intravenous access was established upon arrival in the operating room. Besides routine monitoring, bispectral index (BIS) was used to assess anesthesia depth, and invasive radial arterial pressure monitoring was employed. Remimazolam besylate (R-pump) and propofol (B-pump) were administered via TCI. Effect-site concentration gradients for remimazolam were set at 0, 0.3, 0.6, 0.9, and 1.2 μg/mL, while propofol gradients were 0, 1, 2, 3, and 4 μg/mL. Each remimazolam concentration was paired with every propofol concentration. The R-pump was initiated first until the target concentration stabilized for 30 seconds, followed by the B-pump. Both drugs were maintained at target concentrations for 30 seconds before trial cessation. BIS values, mean arterial pressure (MAP) and heart rate (HR) were recorded. Results: Thirty-seven patients were enrolled, with 35 completing the study. SynergyFinder analysis revealed a synergy score of 15.00 for sedation (measured by BIS) and 5.28 for blood pressure (measured by MAP). Conclusion: Combined TCI induction with remimazolam besylate and propofol exhibits synergistic effects on sedation and additive effects on blood pressure. Trial registration： This study was approved by the Ethics Committee of Affiliated Tumor Hospital of Xinjiang Medical University (Approval No. K-2024004) and registered at the Chinese Clinical Trial Registry (ChiCTR2400084302 on 2024-05-14).