Multimodal Opioid-Free Anesthesia in RIRS

The goal of this clinical trial is to evaluate whether a dexmedetomidine-ketamine based opioid-free anesthesia (OFA) protocol can provide effective analgesia compared to conventional fentanyl-based anesthesia in adult patients undergoing elective retrograde intrarenal surgery (RIRS). The main questions it aims to answer are: Does opioid-free anesthesia reduce postoperative opioid consumption compared to fentanyl-based anesthesia? Does opioid-free anesthesia result in lower postoperative pain scores? Researchers will compare the dexmedetomidine-ketamine group to the fentanyl-based anesthesia group to see if opioid-free anesthesia reduces opioid requirements and improves recovery quality. Participants will receive either a dexmedetomidine-ketamine based OFA protocol or conventional fentanyl-based anesthesia during surgery and will be monitored for pain, opioid consumption, and recovery outcomes postoperatively.