Effect of Dexmedetomidine as an Adjuvant to Bupivacaine in Supraclavicular Brachial Plexus Block
Introduction: The objective of this study was to evaluate the effect of 50μg dexmedetomidine on the onset and duration of block and duration of analgesia when used as an adjuvant to bupivacaine in ultrasound guided supraclavicular brachial plexus block.
Methods: Eighty patients of ASA physical status I and II undergoing elective upper limb surgery under ultrasound guided supraclavicular brachial plexus block were randomly divided into two groups: Group D and Group B. Group D (n=40) received 19.5 ml of 0.5% bupivacaine with 0.5 ml (50 μg) dexmedetomidine. Group B (n=40) received 19.5 ml of 0.5% bupivacaine with 0.5 ml normal saline. Onset time of sensory and motor block, duration of sensory and motor block and duration of analgesia was recorded.
Results: Onset time of sensory block (10.55±4.84 min in Group D vs 12.50 ±5.20 min in Group B) and motor block (15.85±5.9min in Group D vs 18.35±5.6min in Group B) though earlier in Group D as compared to Group B was not statistically significant (p value =.087 for sensory block and p value=.058 for motor block). The duration of sensory block (772.20 ±167.84 min in Group D vs 398.38 ±129.839min in Group B) and motor block (725.63±140.964min in Group D vs 361.88±128.764 min in Group B) was statistically significantly prolonged in Group D (p value= .000 for sensory and p value =.000 for motor block). The Duration of analgesia (845.93±184.545min in Group D vs 430.04±121.307 min in Group B) was also statistically significantly prolonged in group D (p value= .000).
Conclusions: Dexmedetomidine (50 μg) as an adjuvant to 0.5% bupivacaine solution in ultrasound guided supraclavicular brachial plexus block prolongs the duration (sensory and motor) of block as well as the duration of analgesia with no effect on the onset time of block.
Keywords: brachial plexus block; bupivacaine; dexmedetomidine. Correspondance: Dr.