A prospective study comparing magnesium sulphate versus clonidine as adjuvants to epidural bupivacaine for lower limb and lower abdominal surgeries.

Epidural anesthesia is widely used for lower limb and abdominal surgeries due to its ability to provide effective intraoperative anesthesia and prolonged post-operative analgesia with stable hemodynamics. Adjuvants such as magnesium sulphate, an NMDA receptor antagonist and clonidine, and α2-adrenergic agonist, can enhance block quality through distinct mechanisms. Hence, this prospective randomized study included 80 adult patients (ASA III) undergoing elective lower limb or abdominal surgery under epidural anesthesia, divided into two groups of 40 each: Group M received magnesium sulphate and Group C received clonidine added to bupivacaine. Parameters evaluated included onset and duration of sensory and motor block, sedation, side effects and hemodynamic changes. Magnesium sulphate produced a faster onset of block, while clonidine resulted in prolonged analgesia and motor block, with mild hypotension and bradycardia observed more frequently. Thus, we show that both agents safely optimize epidural anesthesia magnesium for quicker onset and clonidine for extended pain control depending on surgical needs.