Comparison of different concentration of dexmedetomidine added to ropivacaine in ultrasound guided supraclavicular block for orthopedic forearm surgery-a prospective, randomized, comparative clinical study

Abstract

There is no fix and ideal dose is known for dexmedetomidine as an adjuvant in brachial plexus block. So this study was performed to evaluate different doses of dexmedetomidine added to 0.5% ropivacaine, with the primary outcome of the duration of analgesia. Secondary outcomes included the effect on block characteristics, sedation, hemodynamics and adverse effects.Totally 60 adult patients were randomly allocated to two equal groups (n = 30) using computer generated randomization. Patients in Group RD50 received 24 ml 0.5% ropivacaine + 50 µg of dexmedetomidine and Group RD100 received 24 ml 0.5% ropivacaine + 100 µg of dexmedetomidine in ultrasonography guided supraclavicular block.The primary aim was the duration of analgesia and secondary aim were onset and duration of the sensorimotor blockade, hemodynamic variables, sedation score, and adverse effects The data were interpreted with the help of t-test and Chi-square test.In group RD50, the onset of both sensory and motor block was 8.18 ± 1.49 min and 14.11 ± 2.09 min, respectively, while in group RD100 it was 8.23 ± 1.41 min and 14.06 ± 2.44 min, respectively. The duration of analgesia was similar in both groups (862.32 ± 45.51 vs. 864.43 ± 44.02 min; P >.05). The occurrence of bradycardia was observed significantly greater in RD100 group patients.The addition of 100 µg dexmedetomidine to ropivacaine has similar effects on block characteristics and duration analgesia with a higher incidence of bradycardia as compare to 50 µg.