Ultrasound-guided block of the feline sciatic nerve

This study was conducted to validate an ultrasound-guided technique to block the sciatic nerve in cats. An anatomical study was first carried out in four feline cadavers to evaluate the feasibility of the glutea (cranial and caudal), femoris and poplitea ultrasonographical approaches for the sciatic nerve block. The results showed that the femoris approach was optimal because the region was free of vascular and bony structures, and the needle was easily visualised in-plane. Then, the efficacy of the femoris ultrasonographical approach to block the sciatic nerve was tested in six healthy adult experimental cats. A dose of 2 mg/kg lidocaine 2% diluted in saline to a final volume of 1 ml was administered in all cats. The blockade was successful in all cases and the cats recovered uneventfully. This study shows the usefulness of the femoris approach in performing an ultrasound-guided blockade of the sciatic nerve in cats.