Final answer:
Fernand Cathelin was the first person to perform a percutaneous brachial plexus block.
Step-by-step explanation:
The first person to perform a percutaneous brachial plexus block was Fernand Cathelin. In 1901, Cathelin developed the technique, advancing regional anesthesia. The percutaneous approach involves injecting anesthetic near the brachial plexus, effectively blocking pain signals to the upper limb. August Bier, while influential in regional anesthesia, is not credited with this specific innovation. Cathelin's pioneering work laid the foundation for modern techniques in upper limb anesthesia, significantly impacting surgical and pain management practices. It's crucial to acknowledge the contributions of Fernand Cathelin to the evolution of regional anesthesia in medical history.