Background: The efficacy of Nalbuphine and Fentanyl as adjuvants to Bupivacaine in supraclavicular brachial plexus blocks remains a significant point of study in anesthesia, particularly for upper extremity surgeries.

Methods: This randomized study compared Nalbuphine and Fentanyl added to Bupivacaine in 60 patients undergoing upper extremity surgeries. The onset and duration of sensory and motor blocks, as well as hemodynamic parameters, were evaluated.

Results: Nalbuphine demonstrated a significantly faster onset of sensory (5.03 ± 0.88 minutes) and motor blocks (7.1 ± 0.84 minutes) compared to Fentanyl (sensory: 7.5 ± 0.5 minutes, motor: 8.9 ± 0.831 minutes), with p < 0.001. The duration of sensory and motor blocks was also significantly prolonged in the Nalbuphine group (sensory: 360.87 ± 8.64 minutes, motor: 348.17 ± 12.54 minutes) compared to the Fentanyl group (sensory: 344.9 ± 12.24 minutes, motor: 324.1 ± 14.04 minutes), p < 0.001. Hemodynamic parameters were stable and comparable between the groups.

Conclusion: Nalbuphine, as an adjuvant to Bupivacaine, offers a faster onset and longer duration of both sensory and motor blocks in supraclavicular brachial plexus blocks compared to Fentanyl, with maintained hemodynamic stability.