Saline vs. dextrose for local anesthetic dilution in brachial plexus block: A randomized study

Higher sodium ions in saline diluted local anesthetic may reduce the anesthetic action of the drug as injected around the nerves. However, the impact of local anesthetic dilution agents on the quality of peripheral nerve blockades has not yet been widely investigated. This study was aimed at evaluating the impact of lidocaine dilution with normal saline vs dextrose 5% on onset time of supraclavicular approach to brachial plexus block. Sixty American Society of Anesthesiologists class 1or2 patients, scheduled for elective upper extremity surgeries under sono-guided supraclavicular block were randomly assigned to receive lidocaine 2% diluted with either dextrose 5% or normal saline. At the end of lidocaine injection, sensory and motor blocks were evaluated at 5 min intervals for 30 min in the areas innervated by median, radial, ulnar and musculocutaneous nerves. Block onset time and number of patients with complete sensory or motor blockade were similar in both groups. Lidocaine diluted with either normal saline or dextrose 5% produces comparable sensory and motor block onset time and success rate in ultrasound guided supraclavicular block.