Response Surface Modeling of Remimazolam and Sevoflurane

This prospective randomized open-label study aims to investigate the pharmacodynamic interaction between remimazolam and sevoflurane during general anesthesia using response surface modeling. Although remimazolam has favorable hemodynamic stability compared with propofol, its hypnotic effect may be less predictable and poorly correlated with conventional sedation monitoring indices such as the bispectral index (BIS). In clinical practice, remimazolam and sevoflurane are often combined during induction and maintenance of anesthesia; however, the optimal interaction between these agents remains unclear. This study will evaluate whether the interaction between remimazolam and sevoflurane is synergistic, additive, or infra-additive using two representative response surface interaction models: the Minto model and the Greco model. BIS values and predicted effect-site concentrations will be analyzed using NONMEM software.