Ultrasound guidance for regional anesthesia procedures

Introduction Peripheral nerve blocks have traditionally been performed employing anatomic landmarks to locate sensory and motor nerves. Over the past two decades, nerve stimulation (NS) techniques have increased in popularity, using concentrated electrical impulses to depolarize, stimulate, and thus identify specific nerves. In recent years, the application of ultrasound (US) to visualize nerves and the spread of local anesthetic has revolutionized the practice of regional anesthesia. US-guided regional anesthesia requires knowledge of the anatomy as well as basic ultrasound principles, which will allow practitioners to choose their equipment wisely. A number of linear and curved array US probes are available, and newer echogenic needles with distance markers continue to improve visualization. Portable US machines are available that will provide diagnostic-quality images for block performance.