Dexmedetomidine versus sufentanil as adjuvants to bupivacaine for brachial plexus block during upper extremity surgery: a randomized clinical trial

BACKGROUND: Brachial plexus block (BPB) has been accepted as a reliable alternative for general anesthesia in upper limb surgeries. Adding adjuvant drugs like dexmedetomidine and sufentanil has been shown to have clinical and pharmacologic advantages. In this randomized parallel clinical trial, we aim to compare the effects of these two adjuvants for bupivacaine in BPB. METHODS: In this double-blinded study, by using computer-assisted block randomization, 40 patients ranged from 20 to 65 years old and scheduled for elective upper limb surgeries were assigned to two equal study groups (n = 20), receiving 1 mL of 5 ..g.mL(-1) sufentanil (group S) or 1 mL of 100 ..g.mL(-1) dexmedetomidine (group D) in adjunction to 30 mL of 0.5% bupivacaine for supraclavicular BPB under the guidance of ultrasonography. Characteristics of local anesthesia and postoperative analgesia were evaluated (n = 40). RESULTS: The duration of blocks significantly improved in group S (sensory: estimated median difference (EMD) [95%CI] = 100.0 [70.0...130.0], p < 0.001; motor: EMD [95%CI] = 120.0 [100.0...130.0], p < 0.001). Group S also had significantly longer postoperative analgesia and lower opioid consumption within 24 hours after the surgery (EMD [95%CI] = 4.0 [3.0...7.0], p < 0.001; EMD [95%CI] = -5.0 [-5.0...-5.0], p < 0.001; respectively). None of the patients showed adverse effects concerning vital signs, nausea, or vomiting. CONCLUSION: Our study showed that during ultrasound-guided supraclavicular BPB, sufentanil is a fairly better choice than dexmedetomidine as an adjuvant for bupivacaine and can provide preferable sensory and motor blocks. No significant side effects were seen in either of the study groups.