Comparative study to assess the efficacy of ropivacaine (0.25%) with magnesium sulfate versus ropivacaine (0.25%) with dexmedetomidine in USG-guided pectoral nerve block type I and II in unilateral breast surgery

Background: Post-operative pain following breast surgery can impair recovery and contribute to chronic pain syndromes. Ultrasound-guided pectoral nerve block (PECS I and II) blocks have emerged as effective regional anesthesia techniques. Adding adjuvants to ropivacaine may prolong analgesia and enhance patient comfort. Aims and Objectives: This study aims to compare the efficacy of 0.25% ropivacaine with dexmedetomidine versus 0.25% ropivacaine with magnesium sulfate in PECS I and II blocks for unilateral breast surgery. Materials and Methods: In this prospective, randomized, double-blind trial, 100 American Society of Anesthesiologists I–II female patients aged 18–60 years undergoing unilateral breast surgery under general anesthesia were allocated equally to receive PECS I and II blocks with ropivacaine plus dexmedetomidine (Group A) or ropivacaine plus magnesium sulfate (Group B). Primary outcomes included post-operative pain scores, Visual Analog Scale (VAS), time to first rescue analgesia, and total 24-h analgesic consumption. Secondary outcomes were intraoperative hemodynamics, patient satisfaction, and adverse effects. Results: Group A demonstrated significantly lower VAS scores at 1 h (1.61±0.51 vs. 1.92±0.57, P=0.02) and 6 h (2.33±0.68 vs. 3.09±0.72, P=0.001) postoperatively. Time to first rescue analgesia was longer in Group A (9.8±1.5 h vs. 6.5±2.0 h, P=0.002) with reduced paracetamol use over 24 h (1.905±0.450 g vs. 2.915±0.651 g, P=0.001). Patient satisfaction was higher in Group A (8.8±0.7 vs. 7.9±1.0, P=0.003). Hemodynamic parameters and adverse effects were comparable, though bradycardia was more frequent in Group A without clinical significance. Conclusion: Dexmedetomidine as an adjuvant to ropivacaine in PECS blocks provides superior early post-operative analgesia, prolonged pain-free intervals, reduced analgesic consumption, and higher satisfaction compared to magnesium sulfate, with similar safety.