Development of complications in ultrasound-guided regional anesthesia vs neurostimulation

The use of peripheral nerve block techniques has significantly increased over the last two decades; as a consequence, development of complications has also increased. Neurostimulation has been the technique of choice for locoregional anesthesia for many years and has even been considered the gold standard. Compared with location by means of paresthesia, this technique reduces the potential risk of postoperative neuropathy, as it limits any direct contact between the needle and the nerve structure. Neurostimulation provides high efficacy with a minimum complication rate; currently, however, as ultrasound provides real time visualization of the nerve, needle and local anesthetic distribution relationship, the use of neurostimulation is less prevalent. Additionally to an apparent improvement of ultrasound-guided peripheral block success rate, there are also many trials available promoting the decrease of neurologic complications. Thus the unavoidable question comes up: is ultrasound the quality gold standard for locoregional anesthesia today? Should we rule out formerly used techniques? The current evidence for maintaining routine and exclusive use of ultrasound over any other peripheral nerve block method is limited. So, why not use all anesthetic techniques available to us, that is neurostimulation, injection pressure control, and ultrasound, to bring the complication rate down?