Effect of Remimazolam Versus Propofol Total Intravenous Anesthesia on Intraoperative Hemodynamic Stability in Patients Undergoing Thoracic or Abdominal Endovascular Aortic Repair

• Remimazolam Besylate (Drug): * Continuous drug: remimazolam diluted to 2 mg/mL in normal saline * Induction: 6 mg/kg/h continuous infusion * Maintenance: 1-2 mg/kg/h (titrated to PSI 25-50, max 2 mg/kg/h) * Reversal at end of procedure: flumazenil 0.2-0.5 mg
• propofol (Drug): * Continuous drug: propofol (undiluted, 20 mg/mL) * Administration: target-controlled infusion (TCI, Marsh model) * Induction: effect-site target concentration 4 μg/mL * Maintenance: 2-4 μg/mL (titrated to PSI 25-50)

Primary outcomes

• Time-weighted average (TWA) of the vasoactive-inotropic score (VIS) [From the start of anesthetic administration to the start of femoral access site hemostasis (intraoperative, up to 300 minutes)]: Time-weighted average (TWA) of the vasoactive-inotropic score (VIS), calculated from the start of anesthetic administration to the start of hemostasis at the femoral access site. VIS reflects the cumulative dose of vasoactive and inotropic agents used to maintain target blood pressure during the procedure.

Secondary outcomes

• Cumulative norepinephrine dosage [From the start of anesthetic administration to the start of femoral access site hemostasis (intraoperative, up to 300 minutes)]: Cumulative norepinephrine dosage including bolus dose
• Peak VIS [From the start of anesthetic administration to the start of femoral access site hemostasis (intraoperative, up to 300 minutes)]: Maximum VIS value recorded during the assessment period
• Time-weighted average of cumulative norepinephrine usage [From the start of anesthetic administration to the start of femoral access site hemostasis (intraoperative, up to 300 minutes)]: Time-weighted average of cumulative norepinephrine usage including bolus dose

Other outcomes

• Time-weighted average patient state index (PSI) during the procedure [From the start of anesthetic administration to the start of femoral access site hemostasis (intraoperative, up to 300 minutes)]
• Time-weighted average intraoperative mean arterial pressure [From the start of anesthetic administration to the start of femoral access site hemostasis (intraoperative, up to 300 minutes)]
• Duration and area under the curve (AUC) out of target mean arterial pressure range [From the start of anesthetic administration to the start of femoral access site hemostasis (intraoperative, up to 300 minutes)]: Duration and area under the curve (AUC) out of target mean arterial pressure range (minutes and mmHg·minutes)
• Average amount of remimazolam, propofol, and remifentanil used (mg/kg/hr, µg/kg/min, µg/kg/min, respectively) [From the start of anesthetic administration to the start of femoral access site hemostasis (intraoperative, up to 300 minutes)]: Average amount of remimazolam, propofol, and remifentanil used (milligrams per kilogram per hour, micrograms per kilogram per minute, and micrograms per kilogram per minute, respectively)
• Incidence and severity of unintended patient movement or spontaneous breathing during general anesthesia (graded as minor, transient surgical interruption, or leading to patient complications) [From the start of anesthetic administration to the start of femoral access site hemostasis (intraoperative, up to 300 minutes)]
• Frequency and total dose of bolus administration of vasoactive-inotropic agents (including norepinephrine) [From the start of anesthetic administration to the start of femoral access site hemostasis (intraoperative, up to 300 minutes)]
• Time-weighted average usage of vasopressors or inotropes, other than norepinephrine [From the start of anesthetic administration to the start of femoral access site hemostasis (intraoperative, up to 300 minutes)]
• Weight-adjusted fluid used (crystalloids and colloids, separately) [From the start of anesthetic administration to the start of femoral access site hemostasis (intraoperative, up to 300 minutes)]
• Incidence of blood transfusion, type of blood products, and units transfused [From the start of anesthetic administration to the start of femoral access site hemostasis (intraoperative, up to 300 minutes)]
• Incidence of bradycardia (<45 beats per minute) requiring treatment [From the start of anesthetic administration to the start of femoral access site hemostasis (intraoperative, up to 300 minutes)]
• Time to loss of consciousness [From the start of anesthetic administration to loss of consciousness (intraoperative, up to 30 minutes)]
• Time to reaching Patient State Index (PSI) <=50 [From the start of anesthetic administration to the first Patient State Index ≤50 (intraoperative, up to 30 minutes)]
• Time to start norepinephrine continuous infusion [From the start of anesthetic administration to the start of femoral access site hemostasis (intraoperative, up to 300 minutes)]
• Length of stay in the intensive care unit or recovery room after the procedure [From the end of procedure to ICU/recovery room discharge, assessed up to 30 days]
• Length of hospital stay after the procedure [From the end of procedure to hospital discharge, assessed up to 30 days]
• Incidence of postoperative nausea and vomiting (PONV) [within 24 hours postoperatively]: Incidence of postoperative nausea and vomiting (PONV), including nausea, vomiting, and requirement for rescue antiemetics, within 24 hours postoperatively
• Time-weighted average QTc (corrected QT) interval and its change from baseline [From the anesthetic administration to the start of femoral access site hemostasis (intraoperative, up to 300 minutes)]
• Postoperative opioid consumption, expressed as oral (or intravenous) morphine milligram equivalents (MME) [From the end of procedure to discharge, assessed up to 7 days]
• Incidence of postoperative delirium requiring pharmacological management (or clinical intervention) [From the end of procedure to discharge, assessed up to 7 days]

Sex: All, ages: 20 Years to any

Inclusion Criteria:

\- Adults aged 20 years or older scheduled for thoracic or abdominal endovascular aortic repair (TEVAR/EVAR) under general anesthesia for thoracic or abdominal aortic aneurysm

Exclusion Criteria:

* Known or suspected allergy or hypersensitivity to the study drugs
* ASA physical status class IV or higher
* Body mass index (BMI) ≥ 30 kg/m\^2
* Chronic use of opioids or benzodiazepines
* History of alcohol or drug abuse
* Preoperative cognitive impairment
* Severe left ventricular dysfunction (left ventricular ejection fraction < 40%)
* Severe hepatic dysfunction (Child-Pugh class C)
* Severe hypoalbuminemia (< 2.0 g/dL)
* Acute or chronic renal failure requiring dialysis
* Pregnancy or breastfeeding
* Emergency procedure