Rapid Alertness: A Propensity-score Matched, Prospective Observational Study of Remimazolam vs. Propofol Infusion for Sedation in Spinal Anesthesia Non-healthy Patients

Abstract

Objectives: The demand for procedural sedation is increasing, with propofol remaining a popular choice due to its safety and rapid recovery profile. Remimazolam presents a promising alternative, offering a rapid onset and short duration of action. Its favorable safety profile and suitability for continuous infusion make it particularly advantageous. This study aimed to evaluate recovery times following continuous infusion of remimazolam compared to propofol sedation. Methods: A single-center, prospective, observational study was conducted from February to June 2023 and was approved by the Sestre Milosrdnice University Hospital Center Ethics Committee. Ninety American Society of Anesthesiologists II or III patients undergoing infraumbilical orthopedic, vascular, or inguinal hernia repair surgeries under spinal anesthesia were assigned to receive either remimazolam or propofol sedation. Sedation depth was assessed using bispectral index (BIS), Modified Observer’s Assessment of Awareness/Sedation Scale, and Richmond Agitation-Sedation Scale. Sedation onset, duration, and recovery times were recorded, alongside dosage adjustments based on target BIS values of 60–80. Propensity score matching was employed to address confounding variables. Results: Remimazolam exhibited significantly faster recovery times, with a median time to achieve BIS > 80 of 3.0 min (IQR = 2.5), compared to 6.0 min (IQR = 3.0) for propofol, p < 0.001. Remimazolam achieved satisfactory sedative and amnestic effects at a median continuous dose of 0.2 (0.1) mg/kg/h, with comparable sedation durations. Significant differences were observed in intraoperative memory retention: 40.0% of patients in the propofol group vs. 10.0% in the remimazolam group reported memory of the event, p = 0.017. Conclusions: Remimazolam demonstrates superior recovery time and amnestic properties compared to propofol after continuous infusion sedation. Additionally, remimazolam matches or exceeds propofol in efficacy and safety for intraoperative sedation in non-healthy patients undergoing spinal anesthesia.

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