Ultrasound-guided regional anesthesia: current concepts and future trends.

The scope of ultrasound imaging guidance for regional anesthesia is growing rapidly. Preliminary data, although limited, suggest that ultrasound can improve block success rate and decrease complications. In this review, we describe the basic principles of ultrasound scanning and needling techniques for nerve blocks, highlight some of the data on clinical outcome, discuss specific limitations of ultrasound for regional anesthesia, and speculate on the future direction for physician training and competency assessment with this technology.