Remimazolam besylate for anesthesia and intensive care sedation in patients with malignancy: A narrative review of pharmacology, immune effects and clinical evidence

Perioperative and critical care management may influence cancer biology by affecting hemodynamic stability, stress responses, inflammation, and cellular immunity. Although anesthetic and analgesic techniques have been scrutinized for potential effects on tumor recurrence and survival, large randomized trials comparing volatile anesthesia with propofol total i.v. anesthesia have not demonstrated consistent oncological benefits for any specific regimen. Remimazolam besylate is an ultra-short-acting benzodiazepine increasingly used for procedural sedation, general anesthesia, and intensive care unit (ICU) sedation, including in patients with malignancy. Its rapid onset and offset, predominantly CES1-mediated hydrolysis with minimal CYP450 involvement, hemodynamic stability, and reversibility with flumazenil make it an attractive option in this high-risk population. In laparoscopic radical colorectal cancer surgery, remimazolam-based anesthesia preserved perioperative natural killer and T-lymphocyte counts more effectively than propofol, reduced intraoperative hypotension and vasopressor requirements, and improved early postoperative quality of recovery. Randomized trials in mechanically ventilated ICU patients with malignancy show non-inferior sedation efficacy with propofol for both short-term postoperative and longer-term sedation, with similar durations of mechanical ventilation, ICU length of stay, and 28-day survival, but fewer hemodynamic adverse events and lower neutrophil-to-lymphocyte ratios. These findings suggest that remimazolam may better preserve immune and inflammatory homeostasis and organ perfusion in the perioperative and critical care setting. However, existing studies in oncology populations report only short-term physiological and clinical outcomes. None were designed or powered to assess cancer recurrence, metastasis, or long-term survival, and no anesthetic drug has yet demonstrated a definitive oncological survival benefit. At present, the choice of remimazolam for patients with malignancy should be based on its pharmacology, safety, and impact on perioperative and ICU recovery rather than assumed effects on tumor biology, and robust prospective studies with oncological endpoints are needed.