Effect of Intravenous Dexamethasone on Prolongation of Analgesia Following Supraclavicular Brachial Plexus Block

Abstract

Objective: Intravenous dexamethasone prolongs the duration of analgesia and motor block provided by brachial plexus block with plain 0.5% bupivacaine. Material and Methods: After obtaining Ethical Committee’s approval, informed consent was taken from the patients involved in the study. The 60 patients included in the study were divided randomly into two groups with 30 patients in each. In group P, ultrasound guided supraclavicular brachial plexus block was given with 30 ml of plain 0.5% bupivacaine without any additive followed by 2 ml of normal saline intravenously. In group D, ultrasound guided supraclavicular brachial plexus block was given with 30 ml plain 0.5% bupivacaine followed by 8 milligrams (2 ml) dexamethasone intravenously, injected after giving the block. Following this, duration of analgesia and duration of motor block was calculated for both the groups. Results: The mean duration of analgesia in group P (plain bupivacaine 0.5% in block with 2 ml normal saline iv) was 365±20 minutes (approx 6 hours) while the mean duration of analgesia in group D (plain bupivacaine 0.5% in block with 8 mg dexamethasone iv) was 902±30 minutes (approx 15 hours). The duration of motor block noted in group P was 253±32 minutes (approximately 4 hours) and that in group D was 572±36 minutes (approximately 9.5 hours). Both these results were highly significant. (p<0.001). Conclusion: Intravenous (IV) administration of dexamethasone along with supraclavicular brachial plexus block with 0.5% bupivacaine significantly prolongs analgesia as well as motor block provided by the block. As dexamethsone is still not approved for perineural use by the various drug regulatory authorities around the world including FDA and long term effects of perineural dexamethasone are still under study, IV administration of dexamethasone should be preferred over perineural use in contemporary practice of anaesthesia.><0.001) Conclusion: Intravenous (IV) administration of dexamethasone along with supraclavicular brachial plexus block with 0.5% bupivacaine significantly prolongs analgesia as well as motor block provided by the block. As dexamethsone is still not approved for perineural use by the various drug regulatory authorities around the world including FDA and long term effects of perineural dexamethasone are still under study, IV administration of dexamethasone should be preferred over perineural use in contemporary practice of anaesthesia.