The Sonosite SII ultrasound machine provides clear visualization of needle and nerve during block placements, allowing precise placement of local anesthetic with minimal patient discomfort. Interscalene nerve blocks with Sonosite II permit the placement of local anesthetic around the roots or trunks of the brachial plexus at the level of the C6 vertebral body between the anterior and middle scalene muscles. Anesthesiologist Dr. David Auyong MD of Seattle, Washington here reviews scanning techniques and sonographic landmarks for this procedure which is typically performed to provide anesthesia or analgesia for surgery of the shoulder and upper arm.