ABSTRACT : : Various adjuvants are available to increase the duration of analgesia in supraclavicular blocks with local anesthetics. Dexamethasone was selected as a perineural additive in this study as it has been shown to prolong the duration of action of analgesia and also decrease time for onset of action

METHODS : We performed a prospective, randomised, double blinded study.40 ASA I,II and III patients undergoing elective upper limb surgeries were randomly allocated to receive either 30ml local anesthetic(15 ml 2% lignocaine with adr1:200000 with 15ml 0.5% bupivacaine)( groups B,n=20) with 2ml saline or local anesthetic with 8mg Dexamethasone (group BD,n=20) and given supraclavicular brachial plexus nerve block with the assistance of Nerve stimulator and USG guidance. The primary outcome was the duration of analgesia. The secondary outcome was max VAS, total analgesic consumption, and onset of motor and sensory blockade.

RESULTS : Group B required rescue analgesia earlier than those of group BD, which was found to be statistically significant. The total dose of rescue analgesia was higher in group B than in group BD.

CONCLUSIONS : : The addition of dexamethasone to local anaesthetic for supraclavicular blocks decreases the time to onset of sensory and motor blockade and also prolongs the duration of analgesia in peripheral nerve blockade. The mechanism is said to be by the action on glucocorticoid receptors.

CONCLUSION: Addition of 8mg dexamethasone to a mixture of local anesthetic for supraclavicular brachial plexus block significantly and safely prolongs postoperative analgesia that lasted much longer than local anaesthesia alone. It also results in a faster onset of sensory and motor blockade.