Comparison of Dexmedetomidine and Morphine as Adjuvants to Bupivacaine for Epidural Anesthesia in Leg Fracture Surgery: A Randomized Clinical Trial

Background: Epidural block approach and drugs are common options for improving the sensory and motor block duration and postoperative pain management.

Objectives: The study aimed to compare the analgesic effects of dexmedetomidine and morphine as adjuvants to bupivacaine for epidural anesthesia in leg fracture surgery.

Methods: This prospective clinical trial was conducted on patients (n = 80, age range: 18 - 60 years) categorized as ASA class I or II. After a clinical examination, the patients were allocated to receive either lumbar epidural bupivacaine + morphine (BM) (12 mL bupivacaine 0.5% + morphine 2 mg) or bupivacaine + dexmedetomidine (BD) (12 mL bupivacaine 0.5% + dexmedetomidine 1 µg/kg). After drug administration, the sensory block level was assessed at 2-min intervals using the Cold Swab method until it reached the T12 level. At the T12 level of sensory block, the surgery began when motor block reached grade 3 of the modified Bromage scale.

Results: The BD group had a significantly shorter time to reach the sensory and motor block than the BM group (P < 0.001). The duration of sensory and motor block was significantly longer in the group BD than in the BM group (P < 0.001). Moreover, the BD group showed lower VAS scores (P < 0.0001) and longer time to first analgesia demand than the BM group.

Conclusions: Combined bupivacaine + dexmedetomidine prolongs the sensory and motor block duration and controls postoperative pain more effectively, indicating that it is an appropriate combination for epidural anesthesia.