Propofol Versus Dexmedetomidine for Postoperative Nausea and Vomiting in Ureteroscopic Procedures Under Spinal Anesthesia: A Randomized, Placebo-Controlled Clinical Trial - Elgendy, Maged; Marzouk, Sahar; Samir, Enas; Gendy, Beshoy; Abbas, Sherif; Ahmed, Ahmed; Ali, Norhan (Archives of Anesthesiology and Critical Care, 2026)