Abstract: Aim The effect of dexamethasone added in anesthetic mixture was retrospectively analysed.Method two hundrad patients who had each received 5 blocks were divided into two groups.In group B the patients were blocked with an anesthetic mixture consisting of 20ml of 2% lidocaine and 20ml of 0.5% bupivacaine, while in group A, the anesthetic mixture was added by 1ml (5mg)of dexamethasone.Result The onset of complete block and the sustained time in group A were better than those in group B, and there was no harmful effect during the operation or postope rative period.Conclusion dexamethasone added in anesthetic mixture could prolong the anesthetic action which is not influenced by the block times and the more the block times, the more significant is the dexamethasone action.

Key words: dexame thasone, brachial plexus block