Impact of CES1 Genotype on Remimazolam

Inclusion Criteria: * American Society of Anesthesiologists (ASA) physical status 1 or 2 * Age 19-70 years * Elective surgery Exclusion Criteria: * Concomitant regional anesthesia * Uncontrolled hypertension (systolic blood pressure \>180 mmHg) * Uncontrolled diabetes mellitus (HbA1c \>9.0%) * Aspartate transaminase (AST), Alanine transferase (ALT), Total bilirubin \> more than 2 times the normal upper limit * Estimated glomerular filtration rate \<60 ml/min/1.73m2 * Moderate to severe chronic pulmonary obstructive disease or respiratory failure * Emergency * Hepatectomy, Liver transplantation * Cardiopulmonary bypass use * Craniotomy due to head trauma, unstable intracranial pressure, or brain disease * Use of benzodiazepine medications (if tolerance is present) * Anxiety, alcohol/drug dependence, or addiction to tricyclic antidepressants * Reported hypersensitivity and adverse reactions to benzodiazepines, flumazenil, and other agents used during anesthesia * Lactose-related genetic disorders * Myasthenia gravis or myasthenia gravis syndrome * Newly diagnosed myocardial infarction/clinically significant coronary artery disease, cerebral ischemic attack/stroke within 6 months, or significant untreated coronary artery disease * Implanted rate-responsive cardiac pacemaker with a bioelectrical impedance sensor. * Intrinsic brain disorders or other conditions that make it difficult to determine the depth of anesthesia through EEG measurements (e.g., epilepsy) * History of severe allergies * Cognitive impairment that prevents comprehension of the instructions and consent form of this study, in case of sedation * Expected intraoperative blood loss of 1000 ml or more * Judged by the investigator to be unsuitable for participation in this study due to other reasons