A Comparative Study of Supraclavicular Brachial Plexus Block with Clonidine as Adjuvant in Two Different Doses in Upper Limb Surgery

Abstract

Introduction: Supraclavicular route of brachial plexus block is considered as ‘The Spinal of Arm’, in which local anaesthetic agent is delivered at a point where the three trunks are compactly arranged and carry entire sensory, motor and sympathetic innervations of the upper extremity. Aim: To compare the efficacy of two moderate doses of clonidine as an adjuvant to lignocaine and bupivacaine in combination in supraclavicular brachial plexus block by using USG guided method. Materials and Methods: After approval by the research Ethics Committee and written informed consent, the randomised controlled study was carried out in 90 ASA I and II patients, who were posted for unilateral upper limb surgery. Supraclavicular brachial plexus block was performed using an ultrasoundguided technique with a total volume of 30.6 mL of drugs. Group N received 15 mL of 2% lignocaine with adrenaline (1 in 200000) and 15 mL of 0.5% bupivacaine with 0.6 mL of normal. Group C1 received 45 µg of clonidine and Group C2 received 90 µg of clonidine along with the local anaesthetics. The time taken for onset and the duration of sensory and motor blocks were noted until 24 hours postoperatively. Vitals were noted before, during and after anaesthesia. The time required for rescue analgesia was noted along with VAS scores and sedation scores. The results were tabulated and correlations were obtained using ANOVA and Student’s t-test. Results: The mean duration (in minutes) of onset of motor block was 14.6±3.024 in Group N, 7.567±1.0726 in Group C1, 6.033±1.756 in Group C2. The mean duration (in hours) of motor block was 3.8±0.6967 in Group N, 5.65±1.1533 in Group C1, 8.05±0.9035 in Group C2. The mean onset of time (in minutes) of sensory block is 14.9±3.1442 in Group N, 6.8±1.0635 in Group C1 and 5.4±2.4403 in Group C2. The mean duration (in hours) of sensory block was 4.233±0.6915 in Group N, 5.833±1.0367 in Group C1 and 8.417±0.8914 in Group C2. The differences were highly statistically significant (p<0.001). Rescue analgesia was required much earlier in Group N (4.43±0.774 hours) than in Group C1 (6.87±0.9 hours) and C2 (10.43±2.339 hours). Conclusion: Ninety microgram clonidine is an attractive alternative as an adjuvant in the ultrasound-guided supraclavicular block for upper limb surgical procedures especially in those that need quite long time with minimal side effects and excellent quality of postoperative analgesia.

Keywords

• clonidine
• postoperative analgesia
• supraclavicular block