Background and Aims:With the use of ultrasound, a minimal effective volume of 20 ml has been described for supraclavicular brachial plexus block. However achieving a long duration of analgesia with this minimal volume remains a challenge. We aimed to determine the effect of dexamethasone on onset and duration of analgesia in low volume supraclavicular brachial plexus block.Material and Methods:Sixty patients were randomly divided into two groups of 30 each. Group C received saline (2 ml) + 20 ml of 0.5% bupivacaine and Group D received dexamethasone (8 mg) + 20 ml of 0.5% bupivacaine in supraclavicular brachial plexus block. Hemodynamic variables and visual analog scale (VAS) score were noted at regular intervals until 450 min. The onset and duration of sensory and motor block were measured. The incidence of “Halo” around brachial plexus was observed. Student's t-test and Chi-square test were used for statistical analysis.Results:The onset of sensory and motor block was significantly earlier in dexamethasone group (10.36 ± 1.99 and 12 ± 1.64) minutes compared to control group (12.9 ± 2.23 and 18.03 ± 2.41) minutes. The duration of sensory and motor block was significantly prolonged in dexamethasone group (366 ± 28.11 and 337.33 ± 28.75) minutes compared to control group (242.66 ± 26.38 and 213 ± 26.80) minutes. The VAS score was significantly lower in dexamethasone group after 210 min. “Halo” was present around the brachial plexus in all patients in both the groups.Conclusion:Dexamethasone addition significantly increases the duration of analgesia in patients receiving low volume supraclavicular brachial plexus block. No significant side-effects were seen in patients receiving dexamethasone as an adjunct.

The objective of this study is to compare clonidine and dexmedetomidine as an adjuvant to levobupivacaine in supraclavicular brachial plexus block with respect to onset, duration of sensory and motor block and duration of analgesia. MATERIALS AND METHODS A total of 90 ASA grade I and II patients of either sex, aged 18-60 yrs. scheduled for elective upper limb surgeries under supraclavicular brachial plexus block were divided into 3 equal groups in a randomized fashion. Group L (n=30) received 1 mL NS, group LC (=30) received 1 mL (150 g) clonidine and group LD (n=30) received 1 mL (100 g) dexmedetomidine added to 30 mL of 0.5% levobupivacaine. Onset and recovery time of sensory and motor block, duration of analgesia and quality of block were studied in all three groups. RESULTS Onset time of sensory and motor blockade was 12.43±2.56 min and 17.96±3.05 min respectively in group L, 9.03±1.60 min and 15.00±2.40 min respectively in group LC and 8.13±2.51 min and 12.13±2.89 min respectively in group LD. Duration of sensory and motor blockade was 660.16±44.28 min and 535.33±50.66 min respectively in group L, 880.16±55.48 min and 771.83±54.19 min respectively in group LC and 930.66±48.02 min and 811.83±52.08 min respectively in group LD. Time of rescue analgesia was 728.86±45.12 min in group L, 1013.5±59.01 min in group LC and 1159.8±56.8 min in group LD (p<0.05). CONCLUSION Dexmedetomidine when added to LA in supraclavicular brachial plexus block prolongs the duration of sensory and motor blockade and also the time for rescue analgesia as compared to clonidine. Dexmedetomidine also enhances quality of block (LD>LC>C).