The Effects of Local Anesthetic Concentration and Dose on Continuous Infraclavicular Nerve Blocks: A Multicenter, Randomized, Observer-Masked, Controlled Study

Abstract

For continuous infraclavicular nerve blocks, local anesthetic concentration and volume influence perineural infusion effects in addition to the total mass of local anesthetic administered. Insensate limbs were far more common with smaller volumes of relatively concentrated ropivacaine. This is the opposite of the relationship previously reported for continuous popliteal-sciatic nerve blocks. The interaction between local anesthetic concentration and volume is thus complex and varies among catheter locations.