Effect of Nalbuphine as Adjuvant to Bupivacaine for Ultrasound-Guided Supraclavicular Brachial Plexus Block

Background: Nalbuphine is a derivative of 14-hydroxymorphine which is a strong analgesic with mixed k agonist and μ antagonist. Nalbuphine was studied several times as adjuvant to local anesthetics in spinal, epidural and local intravenous block. The aim of this study was to evaluate the effect of nalbuphine as an adjuvant to local anesthetics in supraclavicular brachial plexus block. Patients and Methods: Fifty-six patients undergoing elective forearm and hand surgery under supraclavicular brachial plexus block were allocated randomly into one of two groups of 28 patients each to receive either 25 ml (0.5%) bupivacaine with 1 ml of NS or 25 ml (0.5%) bupivacaine with 1 ml (20 mg) nalbuphine. Onset time and duration of both sensory and motor block, and post-operative analgesia were observed. Result: Nalbuphine group showed significant increase in the duration of motor block (412.59 ± 18.63), when compared to control group (353.70 ± 29.019) p-value < 0.001, also, there was significant increase in sensory duration in nalbuphine group (718.14 ± 21.04) when compared to control group (610.18 ± 26.33) p-value < 0.001, without affecting the onset time of the blockade. And also, there was a significant increase in the duration of analgesic effect in nalbuphine group (835.18 ± 42.45) when compared to control group (708.14 ± 54.57) p-value < 0.001. Conclusion: The present study demonstrates that addition of 20 mg nalbuphine to bupivacaine in supraclavicular brachial plexus block is associated with significant increase in the duration of both sensory and motor block and also prolong the duration of analgesia.