Efficacy of low-dose intravenous dexamethasone for prolongation of analgesia in supraclavicular block

Background
Supraclavicular block is a common technique for analgesia for upper limb surgeries. Because of short duration of analgesia with bupivacaine alone various additive have been used to prolong the action of bupivacaine. We conducted a prospective, randomized, double blind controlled trial. All patients were assessed for onset and duration of sensory and motor block, and postoperative pain relief.
Results
Fifty patients belonging to American Society of Anesthesiologist physical status I–II were divided into two groups (25 in each). A mixture of bupivacaine 0.5% (15 ml) + lignocaine-adrenaline 1.5% (15 ml) were given in both the groups by ultrasound guided supraclavicular block and 2 ml of IV normal saline in group C and 2 ml (8 mg) of IV dexamethasone in group D were given. The mean onset time of sensory and motor block was 8.68 ± 1.81 min and 11.12 ± 1.58 min in group D and 11 ± 2.34 min and 13.2 ± 1.65 min in group C respectively. The duration of sensory and motor block in group D (843.6 ± 62.56 and 576.8 ± 70.40) min were prolonged than to group C (281.28 ± 22.42 and 204.2 ± 12.96) min where  < 0.0001.The duration of analgesia in group D was (895.6 ± 43.98 min) as compared to group C (324.4 ± 27.36 min). At the end of 4 h, the difference of the mean VAS score was statistically significant in both the groups ( < 0.05). There was no statistically significant difference in heart rate and systolic blood pressure in both the groups.
Conclusions
Intravenous dexamethasone significantly prolong the duration of analgesia in supraclavicular block without the side effects.