Background: Anterior and lateral approaches to the sciatic nerve block are performed with the patient in the supine position. This could be an important advantage when mobilization to the limb involved islimited or painful, particularly in emergency conditions. The aim of this prospective, randomized study was to compare these two sciatic nerve blockades performed in an emergency setting.
Materials/Methods: 59 patients undergoing post-traumatic lower extremity surgery under a sciatic nerve block were randomly assigned to either a lateral or an anterior approach. After appropriate positioning of the 150-mm insulated needle using a nerve stimulator, 25 ml of ropivacaine 0.75% were injected. Time to perform the block, sciatic nerve depth, success rate, and patient’s comfort were analyzed.
Results: The mean time to perform the block was 4.9±4.0 min in the anterior group and 6.1±6.9 min in the lateral group (NS). The mean depth of sciatic nerve localization was 107±17 mm in the anterior group and 91±20 mm in the lateral group (P<0.05). Although the success was similar in both group (77% in the anterior group vs 79% in the lateral group), the number of technical failure (sciatic nerve stimulation impossible) was higher with the anterior approach (86% vs 33%; p<0.05).
Conclusions: These data suggest that both techniques are of similar value in an emergency setting.

Keywords: Anesthesia, Anesthesia, Emergency Medical Services - methods, Nerve Block - methods, Sciatic Nerve - physiology, Supine Position, Anesthesia, Emergency Medical Services - methods, Nerve Block - methods, Sciatic Nerve - physiology, Supine Position