Prospective randomized study of interscalene brachial plexus block using 0.5% bupivacaine HCl with or without dexamethasone in shoulder surgery

Abstract

Background Interscalene brachial plexus block is one of the commonly performed techniques for regional anesthesia of the upper extremity. The aim of this study was to compare the analgesic efficacy and duration of 5 ml versus 10 ml of 0.5% bupivacaine HCl with and without 1 ml of dexamethasone in patients undergoing shoulder surgery. Materials and methods This prospective randomized blinded study was carried on 75 American Society of Anesthesiology I and II patients. Patients were assigned randomly to one of the three groups: group A received 10 ml of bupivacaine HCl 0.5%; group B received 5 ml of bupivacaine HCl 0.5%; and group C received 4 ml of bupivacaine HCl 0.5%+1 ml of dexamethasone. Results There was no significant difference between the three groups in the total dose of intraoperative fentanyl dose. A statistically significantly high visual analog scale value was found in group B in comparison with groups A and C at 12 h postoperatively, and a statistically significant low visual analog scale was found in group C after 36 h. There was statistically significant earlier timing of first rescue analgesia requisite in group B and there was a significant difference between group C and the other two groups studied in the total amount of nalbuphine consumed. The incidence of block-related complications was significantly higher in group A compared with the other groups. Conclusion High volume of bupivacaine HCl 0.5% provides perioperative analgesia comparable to low volume, but low volume is safer in terms of the incidence of complications. Addition of dexamethasone to bupivacaine led to prolonged analgesic duration and was accompanied by a lower consumption of postoperative opioids.