Comparison of Dexamethasone and Magnesium Sulphate As Adjuvants To 0.5% Ropivacaine in Ultrasound Guided Supraclavicular Brachial Plexus Block- A Prospective, Randomized, Double Blind Study

Abstract Introduction Peripheral nerve blocks (PNB) are preferred over general anesthesia in upper limb surgeries. Regional nerve blocks work on the principle of blocking conduction of painful stimulus along the pathway of nerve fibres in the region. Ultrasound has made the technique of giving the block easier. Brachial plexus block is the most preferred PNB for upper limb surgeries and supraclavicular approach is used for surgeries for elbow, forearm and hand. Ropivacaine, a long acting S-enantiomer of Bupivacaine, has better sensorimotor differentiation and is less cardiotoxic1. Magnesium Sulphate (MgSO4), a N-methyl-D-aspartate (NMDA) receptor antagonist, plays a role in modulating inflammatory and pain responses by preventing central sensitization caused by peripheral nociceptive stimulation.2 Dexamethasone, a highly potent, long acting glucocorticoid which decreases activity of nociceptive C-fibres and prolongs analgesic duration through systemic anti-inflammatory and local vasoconstrictor effects.2