**1. Introduction**

Epidemiologic data has revealed a progressive rise in the aggregate number of patient surgical visits with an increasing number occurring within the ambulatory setting [1]. Accompanying this rise has been a growing need for adequate, efficient patient anesthesia and analgesia [2]. With a significant proportion of procedures involving focal orthopedic interventions of the knee and shoulder, peripheral nerve blockade has become an increasing trend in anesthetic practice while neuraxial blockade use has decreased [2]. The popularity of peripheral nerve blockade may stem from its demonstrated effectiveness with studies showing improved analgesia and recovery during the postoperative period versus opioids [3] or general anesthetic [4]. In this chapter, we will review ultrasonography and its application to a commonly employed peripheral nerve block, namely, the interscalene block.
