Comparing Efficacy of Perineural Dexmedetomidine with Intravenous Dexmedetomidine as Adjuvant to Levobupivacaine in Supraclavicular Brachial Plexus Block

BACKGROUND: Prolonging postoperative analgesia using various adjuvants has become a trend in regional anesthesia practice. There are literally no studies where different routes of dexmedetomidine have been compared in supraclavicular block. We compared perineural dexmedetomidine and intravenous (i.v.) dexmedetomidine when used as an adjuvant with levobupivacaine using a nerve stimulator-guided supraclavicular block. METHODOLOGY: Sixty patients of either sex, aged between 18 and 60 years, belonging to the American Society of Anesthesiologists Physical Status Classes I and II posted for upper limb surgeries under supraclavicular brachial plexus block were enrolled for a prospective observational study. The patients were categorized into two groups: Group levobupivacine with perineural dexmedetomedine (LDP) received 20 mL of 0.5% levobupivacaine plus 10 mL of 2% lignocaine plus 1 μg.kg(-1) dexmedetomidine perineurally, and Group levobupivacaine with intravenous dexmedetomedine (LDV) received 20 mL of 0.5% levobupivacaine plus 10 mL of 2% lignocaine and 1 μg.kg(-1) dexmedetomidine in 50 mL of normal saline administered as infusion over 10 min and given 10 min before start of the supraclavicular block. Onset and duration of sensory and motor blocks, hemodynamic variables, adverse effects, and duration of analgesia were assessed. RESULTS: Demographic profile, onset and duration of sensory and motor block, and duration of analgesia were comparable in both the groups. The incidence of hypotension was high in Group LDV compared to Group LDP, which was found to be statistically significant (LDP – 2, LDV – 11, P < 0.005). Twelve patients in LDV group had Ramsay sedation score >3 whereas In LDP group two patients had Ramsay Sedation score >3 which was statistically significant (LDP – 2, LDV – 12, P < 0.002). CONCLUSION: The i.v. dexmedetomidine is equally effective as compared to perineural dexmedetomidine with respect to onset and duration of block and duration of analgesia but has greater hemodynamic instability.