Perineural Dexamethasone Prolongs the Duration of Analgesia in Supraclavicular Brachial Plexus Block With Ropivacaine: A Comparative Study

Abstract

Introduction: The analgesia provided by single shot brachial block is of limited duration and hence many perineural adjuvants have been tried to improve block characteristics. We evaluated the effects of adding dexamethasone to ropivacaine on onset and duration of sensory and motor block. Study design: A Prospective, Comparative, Randomized study conducted on 80 patients in a tertiary care centre for duration of 8 months. Materials and Method: Eighty patients aged18-60years, ASA physicalstatus I-II weighing 50-80kg scheduled for surgeries under supraclavicular block were randomised into two groups. Group R(n=40) received 0.5%ropivacaine28ml with 2mlnormal saline and group RD received 0.5%ropivacaine28ml with 2ml(8mg)dexamethasone. Primary outcome was duration of analgesia which is the time interval between onset of sensory block and first rescue analgesia (VAS >5). Secondary outcomes were onset and duration of sensory and motor blockade. Statistical analysis: Chisquare and independent t test were used as test of significance for qualitative and quantitative data respectively. Results: Demographic data were similar in both groups. Mean Duration of analgesia in Group R was 530.3 ± 107.58 min and in Group RD was 887.63 ± 228.56 min (p<0.001).Mean duration of sensory and motor block in Group R was 499.83 ± 113.1min and 499.98 ± 103.38min respectively and in Group RD 856.05 ± 229.36min and 812.3 ± 225.23min respectively (p<0.001). Duration of analgesia, duration of sensory and motor blockade were prolonged in group RD than groupR. Conclusion: Perineural dexamethasone in supraclavicular block with 0.5%ropivacaine prolongs the duration of analgesia and block duration but has no effect on onset of block.