Comparison of Intrathecal Dexmedetomedine and Fentanyl as Adjuvants to Bupivacaine in Spinal Anesthesia for Postoperative Pain Relief in Cesarean Section

Background: Spinal anesthesia is best for cesarean sections due to its effective sensory block and safety but offers limited postoperative pain relief. Adding adjuvants like fentanyl or dexmedetomidine to intrathecal bupivacaine prolongs analgesia, enhances sensory and motor block, reduces anesthetic requirements, and improves maternal recovery and satisfaction. Objectives: to assess postoperative pain and hemodynamic changes following intrathecal administration of low-dose bupivacaine with either dexmedetomidine or fentanyl. Patients and methods: This prospective randomized study included 100 women enduring cesarean delivery under spinal anesthesia at Qena University Hospital. Participants received intrathecal bupivacaine (10 mg) with either fentanyl (10 µg) or dexmedetomidine (5 µg). Hemodynamic parameters, sensory and motor block duration, and postoperative pain were assessed, with rescue analgesia and adverse events carefully monitored. Results: No substantial differences were identified between groups regarding demographic data. MAP were significantly higher in Group 2 at 30 and 60 minutes intraoperatively (p=0.0095 and 0.0042), before surgery ended (p=0.0162), and at 10, 20, and 30 minutes postoperatively (p=0.0238, 0.0054, and 0.0037). HR was significantly higher in Group 2 at 5, 10, 15, and 60 minutes intraoperatively (p<0.0001, 0.0077, <0.0001, <0.0001). Sensory and motor block durations were longer in Group 2 (p<0.0001, 0.0002), and VAS scores were lower (p<0.0001). Adverse effects showed no significant difference: hypotension 42% vs. 34% (p=0.415), bradycardia 40% vs. 46% (p=0.5492), and nausea/vomiting 46% vs. 32% (p=0.1543). Conclusion: Intrathecal dexmedetomidine with bupivacaine provided longer analgesia, prolonged block, and stable hemodynamics than fentanyl, with comparable safety and comfort.