Comparison of the Analgesic Duration of 0.5% Bupivacaine With 1:200,000 Epinephrine Versus 0.5% Ropivacaine Versus 1% Ropivacaine for Low-Volume Ultrasound-Guided Interscalene Brachial Plexus Block: A Randomized Controlled Trial - PubMed

In the context of single-injection low-volume US-ISB, we have demonstrated a similar efficacy between equal concentrations of ropivacaine and bupivacaine. In addition, increasing the concentration of ropivacaine from 0.5% to 1% did not prolong the duration of US-ISB.
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