New technique of sciatic nerve block in the popliteal fossa

A new technique of sciatic nerve block in the popliteal fossa was evaluated in 120 patients using an 18 s.w.g. cannula. Precise placement of the cannula was facilitated with the aid of a nerve stimulator. In addition to an initial dose of 1% prilocaine with adrenaline 1: 200,000 (5 mg kg-1), 5 mL 0.5% bupivacaine was used for blockade of the saphenous nerve distal to the medial tibial condyle. One-third or one-quarter of the initial dose was administered when required for augmentation of anaesthesia or post-operative pain relief. Satisfactory anaesthesia was achieved in 117 patients (97.5%); two patients required general anaesthesia, since repositioning of the cannula after initial application of local anaesthetic was strictly avoided. No post-operative complications relating to the nerve block were observed. This technique of sciatic nerve block in the popliteal fossa provides effective and safe anaesthesia of the lower leg.