RÉSUMÉ
Background Th supraclavicular brachial plexus block (SCBPB) exhibits a good anesthetic and analgesic effect to the upper extremity below the shoulder and reduces the need for opioid consumption. Among many medications, dexamethasone and ondansetron had been used as effective adjuvants to the local anesthetics in BPB. Aim: to compare the block characteristics with dexamethasone versus ondansetron as adjuvant to bupivacaine hydrochloride (BPV) in SCBPB. Materials and methods: 75 patients were allocated and divided into three equal groups. Combined ultrasound and nerve stimulation (CUSNS) - guided SCBPB had been done. Control group (C) received thirty ml of 0,5% bupivacaine with 2 ml of normal saline. Ondansetron group (O) received thirty l of 0.5% bupivacaine with 2 ml of 4 mg of ondasetron. In dexamethasone group (D), patient received thirty ml of 0.5% BPV plus 2 ml of 8 mg dexamethasone. Results: A prolonged effect of both sensory and motor block were observed in both group D and group O (more significant in D) than group C. Total dose of analgesic (tramadol in mgs in 24 hours) was obviously reduced in group D and group O than group C. Conclusion: Dexamethasone had better effects on sensory and motor block duration in comparison with ondansetron. The first time to analgesic request in dexamethasone group was longer than ondansetron group (AU)