Efficacy and Safety of Eleveld PK/PD Model-based Dosing During General Anesthesia

The goal of this randomized, controlled clinical trial is to evaluate the efficacy, safety, and recovery profile of an individualized, Eleveld pharmacokinetic/pharmacodynamic model-guided dosing strategy for remimazolam in adult patients undergoing elective non-cardiac surgery under general anesthesia. The main questions it aims to answer are: Does Eleveld model-guided customized dosing significantly reduce the eye-opening time at the end of surgery compared to standard weight-based dosing? Can the Eleveld model-guided approach prevent relative drug accumulation and delayed emergence while maintaining an adequate depth of anesthesia and comparable hemodynamic stability? Researchers will compare the Experimental Group (Eleveld model-guided dosing) to the Control Group (Standard weight-based label dosing) to see if preemptive dose optimization based on individual patient covariates effectively reduces the total drug consumption, frequency of rescue flumazenil administration, and emergence time. Participants will: * Be randomly assigned to receive remimazolam for the induction and maintenance of general anesthesia according to either the Eleveld model-guided customized regimen or the standard weight-based regimen. * Have their depth of anesthesia continuously monitored using a Bispectral Index (BIS) sensor. * Be assessed for the primary outcome (time to eye-opening upon verbal command after discontinuation of anesthetics) and secondary outcomes, including total drug consumption, hemodynamic stability, and postoperative complications (e.g., re-sedation, delirium, PONV).

Inclusion Criteria: * Patients aged 19 to 79 years undergoing elective non-cardiac surgery expected to last 60 minutes or longer under general anesthesia with endotracheal intubation Exclusion Criteria: * Emergency surgery * Surgery requiring evoked potential (EP) monitoring * Chronic benzodiazepine users * Body Mass Index (BMI) ≥ 35 kg/㎡ * Chronic kidney disease * Hepatic dysfunction or chronic liver disease * Contraindication or history of hypersensitivity to remimazolam * American Society of Anesthesiologists (ASA) physical status ≥ IV * Pregnant women * Contraindication or history of hypersensitivity to flumazenil