Ultrasound-guided regional anesthesia for peripheral nerve blocks: an evidence-based outcome review.

Ultrasound-guided regional anesthesia (UGRA) has increased in popularity over the past 5 years. This interest is reflected by the plethora of publications devoted to technique development, as well as randomized and controlled trials. Despite the excitement around ultrasonography, skeptics argue that there is a lack of evidence-based medicine to support the unequivocal adoption of UGRA as a "standard of care." This article summarizes and critically assesses current data comparing traditional approaches to localizing nerves with those that use ultrasound guidance. In addition, the potential benefits of UGRA that go beyond current information available from comparative studies are explored.