Anesthesia Knowledge Test-6 (AKT-6) Practice Exam – Prep & Study Guide

The duration of action for a 0.5% solution of Bupivacaine, when used for a brachial plexus block, is typically in the range of 8 to 12 hours. However, under certain conditions and with specific techniques, it can extend to up to 12 to 14 hours. This extended duration is due to Bupivacaine's pharmacodynamic properties, which include a higher lipid solubility and a greater protein binding affinity compared to other local anesthetics, allowing it to provide prolonged analgesia.

The clinical effectiveness of Bupivacaine in this context makes it a preferred choice for procedures where extended postoperative analgesia is desired. The responses are influenced by factors such as the volume administered, the injection site, the presence of adjuncts (like epinephrine), and individual patient variations. Given these factors, the answer indicating a duration of 12 to 14 hours correctly reflects the potential extended action of Bupivacaine in regional anesthesia applications such as a brachial plexus block.