Effectiveness of Dexamethasone versus Clonidine as an Adjuvant to Bupivacaine for Ultrasound-guided Supraclavicular Brachial Plexus Block in Patients Undergoing Upper Limb Surgery

Background: Supraclavicular Brachial Plexus Block has become one of the most important anaesthetic techniques for surgeries in the upper limb. In modern anaesthesia practices, various pharmacological agents are used as an adjuvant to provide faster onset and longer duration of analgesia of local anaesthetic agent after single injection peripheral nerve blocks. This study was designed for the evaluation of the effectiveness of dexamethasone versus clonidine as an adjuvant to bupivacaine for Ultrasound-guided Supraclavicular Brachial Plexus Block in patients undergoing upper limb surgery.Methods: This randomized controlled trial was carried out from September 2021 to August 2022 at Dhaka Medical College and Hospital. Patients were included according to inclusion and exclusion criteria. A total of 75 patients were enrolled in the study. Patient’s allocation into three groups were done by computer generation random numbers: Group A- received 18 ml of 0.5% Bupivacaine (plain) and 2 ml of normal saline. Group B- received 18 ml of 0.5% Bupivacaine (plain) with 2ml (10mg) of Dexamethasone, and Group C- received 18 ml of 0.5% Bupivacaine (plain) and 2 ml (100μg) of Clonidine. The required time for onset and duration of sensory and motor block, time for first demand of analgesia and total consumptions of analgesics within 24hours, haemodynamic parameters, and adverse effects were observed among three groups.Result: The demographic profiles were similar between three groups (p > 0.05). Considering the time for complete sensory block (23.6±3.1 vs 18.9±3.2 vs 14.7±3.0) & time for the onset of maximum motor level (29.5±3.9 vs 23.5±3.1 vs 20.8±2.4), significantly less in clonidine (group C) than that of normal saline (group A) & dexamethasone (group B) group (p < 0.05). The Ramsey sedation score was high in group C in first eight hours during postoperative periods than two others groups which was also statistically significant (p < 0.05). The time to regression of sensory block (242.1±16.57 vs 932.9±44.9 vs 739.16 ±13.47) & motor block (175.6±17.5 vs 780.8±26.2 vs 570.6 ±22.0) was significantly longer in group B than that of other two group which was statistically significant (p <0 .05). Similarly in comparison to other two groups, group B had significantly increased (190.8±18.3 vs 810.6±25.8 vs 600.6±24.9) (p < 0.05) in respect of time for motor recovery. On the other hand, group B had significantly increased result in aspect of time for Ist demand of analgesic (260.6±23.0 vs 975.2±29.0 vs 760.8±25.5), significantly decreased total analgesic requirements in 24 hours (232.8±15.5 vs 84.7±13.8 & 166.1±19.4) & also significantly decreased total anti-emetic requirement in 24 hours (11.8±0.3 vs 4.1±0.8 & 8.0±0.0) (p < 0.05) which was statically significant than that of others two groups. All adverse effects were significantly less in group B than in groups A & group C. (p < 0.05).Conclusion: Dexamethasone is more effective than clonidine as an adjuvant to bupivacaine for Ultrasound-guided Supraclavicular Brachial Plexus block.