Comparison of intraoperative hemodynamic parameters between propofol- and remimazolam-based total intravenous anesthesia in patients undergoing robotic gynecologic surgery: a randomized controlled trial protocol.

Introduction: Propofol-based total intravenous anesthesia (TIVA) with remifentanil is widely used for general anesthesia but is frequently associated with hypotension and bradycardia. Remimazolam, an ultra-short-acting benzodiazepine, provides rapid onset and offset, with the additional advantage of reversal by flumazenil, and may result in less hemodynamic depression. Previous randomized studies have largely focused on the induction phase or the incidence of hypotension, with limited data on continuous intraoperative hemodynamic changes during laparoscopic gynecologic surgery. The study is designed to compare prospectively the intraoperative hemodynamic profiles of remimazolam-based versus propofol-based TIVA in patients undergoing robotic gynecologic surgery in the Trendelenburg position. Methods and Analysis: This prospective, single-center, randomized, single-blind, parallel-group superiority trial will be conducted at CHA Ilsan Medical Center, a secondary care university-affiliated hospital. In total, 58 adult patients (aged 19-65 years, American Society of Anesthesiologists physical status I-II) scheduled for elective robotic laparoscopic hysterectomy under general anesthesia will be enrolled and randomly assigned (1:1) to receive either remimazolam- or propofol-based total intravenous anesthesia, both in combination with remifentanil. Continuous invasive mean arterial pressure (MAP) will be monitored using a FloTrac™ sensor (Edwards Lifesciences, Irvine, CA, United States). The primary outcome will be the time-weighted average MAP (TWA-MAP), analyzed using analysis of covariance adjusted for baseline MAP. Secondary outcomes will include the area under the curve for hypertensive and hypotensive burden, as well as the incidence of adverse hemodynamic events, including hypotension, hypertension, bradycardia, and tachycardia. Generalized estimating equations (GEE) will be used to evaluate hemodynamic and respiratory parameters across predefined time points. Discussion: This trial is expected to provide prospective, randomized evidence to compare continuous intraoperative blood-pressure trajectories between remimazolam- and propofol-based TIVA during robotic gynecologic surgery. It is anticipated that the findings will clarify the relative hemodynamic stability of these anesthetic agents under the combined physiological challenges of Trendelenburg positioning and pneumoperitoneum. The findings may inform anesthetic drug selection and intraoperative blood pressure management strategies, enhancing cardiovascular stability and improving postoperative outcomes. Clinical Trial Registration: ClinicalTrials.gov, identifier NCT07251101.