Evaluation of the Efficacy of Two Different Doses of Dexamethasone as an Adjuvant To 0.5% Levobupivacaine in Ultrasonic Guided Supraclavicular Brachial Plexus Block

Background: Dexamethasone is frequently used as an adjuvant to local anesthetics to extend peripheral nerve block analgesia; however, the appropriate perineural dose when paired with 0.5% levobupivacaine for ultrasound-guided supraclavicular brachial plexus block (SCBPB) is unknown.

Objective: The purpose of this study was to assess the analgesic efficacy and block characteristics of two different dosages of perineural dexamethasone (4 mg vs 8 mg) combined with 0.5% levobupivacaine in ultrasound-guided SCBP.

Methods: In this prospective, randomized, double-blind trial conducted at a tertiary care institution, 80 adult patients undergoing elective upper limb surgery were randomly assigned to receive 30 mL of 0.5% levobupivacaine with dexamethasone 4 mg (Group A, n=40) or dexamethasone 8 mg (Group B, n=40). The main outcome was the length of sensory blackout. Secondary outcomes were onset time, duration of motor block, time to first rescue analgesia, postoperative VAS scores for up to 24 hours, and adverse events.

Results: The length of sensory block was substantially longer in Group B than in Group A (13.2 ± 1.4 h versus 10.5 ± 1.2 h, p < 0.001). Group B had a significantly longer motor block duration (11.5 ± 1.3 h versus 8.9 ± 1.1 h, p < 0.001). Group B had a considerably longer wait time to receive their first rescue analgesia (14.4 ± 1.2 h versus 12.0 ± 1.3 h, p < 0.001). Group B experienced considerably reduced postoperative VAS scores after 4 hours (p < 0.05). No significant adverse events were reported in either group.

Conclusion: When perineural dexamethasone 8 mg is combined with 0.5% levobupivacaine, it considerably prolongs sensory and motor block duration and improves postoperative analgesia compared to 4 mg, while having no additional side effects.