Tehran University of Medical Sciences Archives of Anesthesiology and Critical Care 2423-5849 12 1 2026 01 01 18 25 Maged Elgendy Department of Anesthesia, Surgical Intensive Care, and Pain Management, Faculty of Medicine, Cairo University, Cairo, Egypt. Sahar Marzouk Department of Anesthesia, Surgical Intensive Care, and Pain Management, Faculty of Medicine, Cairo University, Cairo, Egypt. Enas Samir Department of Anesthesia, Surgical Intensive Care, and Pain Management, Faculty of Medicine, Cairo University, Cairo, Egypt. Beshoy Gendy Department of Anesthesia, Surgical Intensive Care, and Pain Management, Faculty of Medicine, Cairo University, Cairo, Egypt. Sherif Abbas Department of Anesthesia, Surgical Intensive Care, and Pain Management, Faculty of Medicine, Cairo University, Cairo, Egypt. Ahmed Ahmed Department of Anesthesiology, National Cancer Institute, Cairo University, Cairo, Egypt. Norhan Ali Department of Anesthesia, Surgical Intensive Care, and Pain Management, Faculty of Medicine, Cairo University, Cairo, Egypt. 2025 04 13 2025 04 25 Background: Propofol and dexmedetomidine have a mitigating effect on postoperative nausea and vomiting (PONV). However, their efficacy in preventing PONV in patients following ureteroscopic operations remains uncertain. This study evaluated the efficacy and safety of infusions of dexmedetomidine versus propofol with respect to the incidence of PONV in patients scheduled for ureteroscopic surgeries under spinal anesthesia. Methods: This randomized controlled trial included 72 adult patients scheduled for ureteroscopic surgery under spinal anesthesia with multiple risk factors for PONV (female, history of PONV, non-smoker). The patients were randomized into three groups (24 patients each). The propofol, dexmedetomidine, and control groups received intravenous infusions of propofol, dexmedetomidine, and normal saline, respectively. The study outcomes were the incidence of PONV (primary outcome) as well as the time and need for antiemetics, Ramsay Sedation Scale, and incidence of intraoperative hemodynamic changes (secondary outcomes). Results: Dexmedetomidine infusion resulted in significantly lower PONV scores and heart rates during and after surgery compared to the propofol and control groups. Both intervention groups had significantly deeper sedation, but dexmedetomidine was more sedating than propofol (p = 0.001) in comparison to the control group. At 40 and 60 minutes intra- and postoperatively, both the propofol and dexmedetomidine groups had a significant reduction in mean blood pressure in comparison to the control group. Mean blood pressure was similar in the two groups. Conclusion: During ureteroscopic procedures under spinal anesthesia, dexmedetomidine effectively and safely reduces the incidence of PONV in highly susceptible patients. It also provides deeper sedation and better hemodynamic control compared to propofol. https://aacc.tums.ac.ir/index.php/aacc/article/view/1262