Comparison of dexamethasone and clonidine as an adjuvant to 1.5% lignocaine with adrenaline in infraclavicular brachial plexus block for upper limb surgeries

The role of clonidine as an adjuvant to regional blocks to hasten the onset of the local anesthetics or prolong their duration of action is proven. The efficacy of dexamethasone compared to clonidine as an adjuvant is not known. We aimed to compare the efficacy of dexamethasone versus clonidine as an adjuvant to 1.5% lignocaine with adrenaline in infraclavicular brachial plexus block for upper limb surgeries. Fifty three American Society of Anaesthesiologists-I and II patients aged 18-60 years scheduled for upper limb surgery were randomized to three groups to receive 1.5% lignocaine with 1:200,000 adrenaline and the study drugs. Group S (n = 13) received normal saline, group D (n = 20) received dexamethasone and group C (n = 20) received clonidine. The time to onset and peak effect, duration of the block (sensory and motor) and postoperative analgesia requirement were recorded. Chi-square and ANOVA test were used for categorical and continuous variables respectively and Bonferroni or post-hoc test for multiple comparisons. P < 0.05 was considered significant. The three groups were comparable in terms of time to onset and peak action of motor and sensory block, postoperative analgesic requirements and pain scores. 90% of the blocks were successful in group C compared to only 60% in group D (P = 0.028). The duration of sensory and motor block in group S, D and C were 217.73 ± 61.41 min, 335.83 ± 97.18 min and 304.72 ± 139.79 min and 205.91 ± 70.1 min, 289.58 ± 78.37 min and 232.5 ± 74.2 min respectively. There was significant prolongation of sensory and motor block in group D as compared to group S (P < 0.5). Time to first analgesic requirement was significantly more in groups C and D as compared with group S (P < 0.5). Clinically significant complications were absent. We conclude that clonidine is more efficacious than dexamethasone as an adjuvant to 1.5% lignocaine in brachial plexus blocks.