Ultrasound in acute and chronic pain: why is it necessary?

High success rates are attainable using state-of-the-art multiple electrical nerve stimulation, loss-of-resistance or fluoroscopic guidance techniques in most interventional acute and chronic pain techniques. Nevertheless, ultrasound (US) guidance for regional anesthesia and pain medicine offers compelling advantages in terms of precise location of anatomical structures, controlled needle advancement and local anesthetic deposition. Accurate models are needed to define criteria for the reproducibility of US examination and nerve block. Familiarization with US imaging is quickly becoming necessary as the next step in the evolution of interventional techniques for treating pain; consistent training by competent professionals is necessary to effectively leverage on the advantages of this technology.