Comparative Study Between Ketamine and Dexamethasone as Adjuvants to Bupivacaine in Ultrasound-Guided Supraclavicular Block in Patients Undergoing Upper-Limb Surgery
Ultrasound-guided supraclavicular brachial plexus block is widely used for anaesthesia and postoperative analgesia in upper-limb surgery. Although bupivacaine provides prolonged regional anaesthesia, its duration may be insufficient for postoperative pain control. Adjuvants such as ketamine and dexamethasone have therefore been used to improve block characteristics and prolong analgesia. Objective: To compare ketamine and dexamethasone as adjuvants to bupivacaine for ultrasound-guided supraclavicular brachial plexus block in patients undergoing upper-limb surgery. Methods: This double-blind randomized controlled trial was conducted in the Department of Anesthesiology, Aziz Bhatti Shaheed Teaching Hospital, Gujrat from June to December 2025. Sixty patients aged 18–60 years with ASA physical status I or II undergoing elective upper-limb surgery were randomized into two equal groups. Group K received bupivacaine with 50 mg ketamine, while Group D received bupivacaine with 8 mg dexamethasone. Sensory and motor block onset and duration, postoperative analgesia, haemodynamic stability, and adverse events were compared between the groups. Results: Baseline characteristics were comparable between the groups. Sensory block onset was significantly faster with dexamethasone than ketamine (13.5 ± 3.8 vs. 16.8 ± 4.5 minutes; P=0.003), as was motor block onset (15.8 ± 4.2 vs. 19.2 ± 5.1 minutes; P=0.006). Dexamethasone significantly prolonged sensory block duration (760.5 ± 105.2 vs. 415.3 ± 85.6 minutes), motor block duration (705.4 ± 98.1 vs. 370.2 ± 75.4 minutes), and postoperative analgesia (752.5 ± 110.5 vs. 382.6 ± 88.4 minutes; all P<0.001). Haemodynamic parameters remained stable in both groups, and no major adverse events were observed. Conclusion: Dexamethasone was more effective than ketamine as an adjuvant to bupivacaine for ultrasound-guided supraclavicular block, providing faster block onset and substantially longer sensory block, motor block, and postoperative analgesia without major adverse effects.