Changes in Autonomic Nervous Activity and Blood Pressure After Anesthesia Induction: Remimazolam Versus Propofol

The goal of this clinical trial is to compare the effects of changes in autonomic nervous activity on changes in blood pressure after anesthesia induction between propofol and remimazolam in patients undergoing low-risk surgery. The main questions it aims to answer are:Does remimazolam shift sympathovagal balance toward parasympathetic predominance less than propofol?Does the less shift in sympathovagal balance toward parasympathetic predominance attenuate the reduction in blood pressure? Participants will be administered either propofol or remimazolam for anesthesia induction, after which the autonomic nervous activity and blood pressure will be measured.Researchers will compare the propofol and remimazolam groups to see if remimazolam causes less shift in sympathovagal balance toward parasympathetic predominance and subsequently attenuates the reduction in blood pressure.

Inclusion Criteria:Age between 20 and 60 yearsAmerican Society of Anesthesiologists physical status of 1Elective low-risk surgery requiring general anesthesia, the duration of which is shorter than 2 hours and 30 minutes (e.g., Laparoscopic cholecystectomy, Functional endoscopic sinus surgery, etc.)Body mass index less than 30 kg/m2Exclusion Criteria:Arrhythmias or cardiac conduction disordersDisease or medical conditions affecting autonomic nervous activity (hypertension, diabetes mellitus, ischemic heart disease, congestive heart failure, cerebrovascular accident, chronic kidney disease, thyroid dysfunction, etc.)Valvular heart diseaseUse of medications affecting autonomic nervous activity or cardiac conduction (e.g., beta blocker)Limited mouth opening, limited head and upper neck extension, history of obstructive sleep apnea, or Modified Mallampati class 3 or 4Serum electrolyte abnormalitiesSevere hypovolemiaPsychiatric diseases