A study to compare the effect of intravenous versus perineural dexamethasone on random blood sugar in patients undergoing upper limb surgery under supraclavicular brachial plexus block

Background: Brachial plexus block is the preferred choice of anaesthesia for upper limb surgeries. Local anaesthetics like lignocaine and bupivacaine are used to provide analgesia and anaesthesia. Bupivacaine is the most commonly used local anaesthetic. Various adjuvants like clonidine, dexamethasone, opioids are used to prolong regional blockade, decrease the dosage of local anaesthetic required, shorten the onset time of block and prolong the duration of post-operative analgesia. Dexamethasone has been used as a perineural adjuvant as well as intravenous analgesic and because of its glucocorticoid properties it may cause hyperglycaemia.  Objectives: To compare the difference in blood sugar levels after the administration of dexamethasone by the perineural and intravenous route in supraclavicular brachial plexus block in non-diabetic patients undergoing upper limb surgeries. Material and methods: Total of 105 patients will receive USG guided supraclavicular brachial plexus block with 25mL of 0.5% bupivacaine. They’ll be randomly allocated to one of the three study groups of 35 each. Group I: 0.1mg/kg dexamethasone diluted in 2 mL normal saline (NS) (perineural) + 100 mL NS (Intravenous); Group II: 2 mL NS (perineural) + 0.1 mg/kg dexamethasone in 100mL NS (Intravenous); Group III: 2mL NS (perineural) + 100mL NS (Intravenous). Total volume given perineurally will be 27ml. Maximum dose of dexamethasone to be used will be 6mg. Random blood sugar will be measured at baseline (T0) and then 2, 4, 8, and 24 hours after T0. Expected Benefits: This study will help us to evaluate the effect of dexamethasone on random blood sugar levels in supraclavicular block when given intravenous vs perineurally.