The Comparison of Dexmedetomidine to Dexamethasone as Adjuvants to Bupivacaine in Ultrasound-Guided Infraclavicular Brachial Plexus Block in Upper Limb Surgeries

Abstract

Background The clinical utility of adjuvants with local anesthesia produces an excellent nerve block with prolonged duration and faster onset. Brachial plexus block is widely used nowadays in patients undergoing upper limb surgery There are several approaches to achieve brachial plexus block such as interscalene, supraclavicular, infraclavicular, and axillary. The objective of this study is to compare the effectiveness of dexamethasone to dexmedetomidine as adjuvants to bupivacaine in patients undergoing ultrasound-guided infraclavicular brachial plexus (USG-ICBP) block. Methods A randomized, prospective, double-blind study was undertaken on the patients posted for upper limb surgeries under ultrasound-guided infraclavicular brachial plexus block. Sixty patients with the American Society of Anesthesiologists (ASA) classes I and II were randomly allocated into two groups. Group A received 25 mL of 0.5% bupivacaine and 1.5 mL (6 mg) of dexamethasone, and group B received 25 mL of 0.5% bupivacaine and 0.75 mL (75 mcg) of dexmedetomidine along with 0.75 mL of 0.9% normal saline (NS). Student's t test or Mann-Whitney test and chi-square test were used for statistical analysis. Results The onset of sensory block was significantly faster in the patients in group B as compared to the patients in group A. In terms of the duration of the block, sensory and motor blocks were maintained for a significantly longer duration in the group A patients as compared to those in group B. Moreover, the duration of postoperative analgesia was significantly longer-lasting in the group A patients. In terms of adverse effects, procedure-related complications such as the failure of the block and inadequate block were comparable across the groups. However, drug-related adverse effects were significantly more common in group B. Conclusion As compared to 75 mcg of dexmedetomidine, the addition of 6 mg of dexamethasone as adjuvant to 25 mL of 0.5% bupivacaine resulted in significantly longer-lasting sensory and motor blocks, postoperative analgesia, and a delayed time for first rescue analgesia without increasing undue adverse effects. Dexmedetomidine use is associated with more sedation as compared to dexamethasone.