Clinical Research Directory

Inclusion Criteria: * Age ≥ 65 years * Elderly hospitalized patients scheduled to undergo general anesthesia * American Society of Anesthesiologists (ASA) physical status I-III * Surgery to be performed in the supine position * Ability to communicate with the investigator and to cooperate in completing the assessment scales * Expected duration of surgery ≥ 2 hours Exclusion Criteria: * Congenital heart disease, severe cardiac conduction block, or implanted cardiac pacemaker; * History of cerebral infarction, cerebral hemorrhage, or stroke within the past 3 months; * Known allergy to remimazolam or propofol; * Severe mental illness, history of analgesic abuse, or addiction to psychotropic drugs; * Patient or family members refuse surgery or anesthesia, or are unable to complete the required questionnaires.