Comparative Evaluation of Dexmedetomidine-Midazolam and Fentanyl-Midazolam for Sedation and Analgesia in Lower Extremity Orthopedic Surgery under Spinal Anesthesia: A Randomized Double-Blind Clinical Trial - Mojgan Rahimi; Mohamad Sorani; Afzal Shamsi; Myasar Jasim Mohamad; Noah Awad Hussain (Archives of Anesthesia and Critical Care, 2026)