Premixed vs Sequential Injections of Lidocaine and Bupivacaine for Supraclavicular Brachial Plexus Block in Patients Undergoing Arteriovenous Fistula Creation

Patients will receive 10 ml of lidocaine 2% then 10 ml of bupivacaine 0.5% with a delay of 120s between injections.

Patients will receive 20 ml of freshly prepared mixtures of 10 ml of lidocaine 2% and 10 ml of bupivacaine 0.5%.