Does Use of Ultrasound Reduce the Rate of Sham Caudal Block in Children

Caudal blocks are one of the most commonly performed regional anesthetics in children and are performed daily for a host of infra-umbilical surgical procedures. A caudal block is an epidural injection, most commonly of local anesthetic into the epidural space as accessed via the sacral hiatus. In children, the sacral hiatus is a normally occurring aperture in which the epidural space may be accessed with extremely minimal risk; as neural tissue ends more proximally. Due to this measure of safety, caudal blocks are preferred in children when compared with standard lumbar epidurals. Caudal blocks are performed blindly using palpation and tactile feedback to assess if the medication is being administered in the correct location. As a result of blind injection, administration of local anesthetic totally or partially outside of the correct site can often be unnoticed or identified after a significant volume has already been injected. With the potential for toxicity of local anesthetic, this may result in either the inability to give a complete dose or an unintentional and often unnoticed sham block "incorrect site of injection".