Ultrasound Guided Nerve Twitch Darwin C. Viernes, MD Regional Anesthesia Fellow Mentor: Loreto Lollo, MD Mapping of Sciatic Nerve Project Objective What we know: We can control pain after leg, foot, and ankle surgery by depositing local anesthetic around the sciatic nerve We can do this either by using ultrasound, nerve stimulation, or a combination of the two Sometimes, pain relief is inadequate when using the ultrasound alone Therefore, our purpose is to measure the best point near the sciatic nerve that gives the most pain relief by combining the ultrasound and nerve stimulator approach to see whether this point is similar in location to other patients. Methods We have IRB approval to enroll 100 patients Designed as a prospective non-randomized trial Under ultrasound guidance, we use a stimulating needle and attempt to find the best plantar flexion response using the minimum amount of current. We record pre-operative VAS scores and 24 hour morphine equivalent consumption At 1 hour post block: VAS scores At 24 hours post block: VAS scores, 24 hour morphine equivalent consumption We record the position where the twitch was obtained, and the position of the catheter after it is placed Lateral Medial Anterior Posterior Preliminary Results n = 31 n = 27 4 removed due to incomplete data Age Mean 51.8 (27-77) BMI Mean ( ) Gender Females n=10 (37%) Males n=17 (63%)