“…These conclusions were based on several different outcomes and demonstrated superiority for US guidance including shorter block performance time, 8,9,12,13,16,18,20,21,[27][28][29]31,33,35 fewer needle passes, 11,17,22,27,30 reduced incidence of vascular puncture, 8,15,16,19 increased proportion of patients with "block success" as defined by surgical anesthesia, 10,[14][15][16]18,20,21,24,[26][27][28][29]31,32,34 reduced procedural pain, 18,21,34 and more rapid sensory/motor onset. 9,10,17,23,30,34 Five studies concluded that there were no differences between nerve localization techniques.…”