Effect of Perineural and Intravenous Dexamethasone on Duration of Analgesia in Supraclavicular Brachial Plexus Block with Bupivacaine: A Comparative Study

BACKGROUND: Perineural dexamethasone has been shown to improve analgesia in single injection supraclavicular block. Systemic mechanism of action of dexamethasone along with safety concerns of perineural route of administration has prompted the investigation of intravenous route as an alternative. AIMS: We aim to compare the effects of dexamethasone as an additive to local anesthetic when used via perineural and intravenous route in terms of duration of analgesia and onset of motor and sensory block. SETTINGS AND DESIGN: The study was done as a prospective comparative observational study conducted in a tertiary care hospital in India among 50 patients during a period of 1 year. MATERIALS AND METHODS: Twenty-five patients aged 18–60 years, belonging to the American Society of Anesthesiologists physical status Classes I and II, receiving supraclavicular block with 0.5% bupivacaine and perineural dexamethasone were compared with similar number of patients receiving the block along with intravenous dexamethasone. Duration of analgesia, onset of sensory block, and onset of motor block were studied. STATISTICAL ANALYSIS: The results were analyzed using Chi-square test for qualitative variables and unpaired t-test for quantitative variables. RESULTS: The duration of analgesia in the group receiving perineural dexamethasone (Group DP) 817.2 ± 88.011 min was comparable to the group receiving intravenous dexamethasone (Group DI) 858.00 ± 86.168, with a P = 0.104. Time to onset of sensory block in Group DP (10.20 ± 1.443 min) was significantly faster than that of Group DI (11.60 ± 1.443) with a P = 0.001. Time to onset of motor block in Group DP (13.92 ± 1.754 min) was significantly earlier than that of Group DI (14.96 ± 1.274 min) with a P = 0.02. CONCLUSION: It is concluded from this study that intravenous and perineural dexamethasone equally prolongs the duration of analgesia in supraclavicular block. However, perineural dexamethasone resulted in a faster onset of motor and sensory blockade.