A randomized double-blind study to evaluate efficacy and safety of epidural magnesium sulfate and clonidine as adjuvants to bupivacaine for postthoracotomy pain relief.

Background: The aim of the study was to compare postoperative pain relief in patients undergoing an elective thoracotomy with thoracic epidural analgesia using single shot magnesium and clonidine as adjuvants to bupivacaine.

Methods: In a randomized prospective study, 60 patients of American Society of Anesthesiologists physical status I-III of either sex, between 20 and 60 years undergoing elective unilateral thoracotomy, were allocated to three equal groups of 20 patients. Each patient received thoracic epidural analgesia using bupivacaine alone (Group A) or with magnesium (Group B) or clonidine (Group C) at the end of surgery during skin closure.