Ultrasound Guided Neuraxial Block in Pediatrics

Abstract

The benefits of pediatric regional anesthesia are many, although nerve blocks, especially at the neuraxial, can be challenging. The safety margin for needle placement is narrow within the spinal canal, the anatomical structures are tightly positioned and the epidural space can be as narrow as 2 mm for epidural blocks. Because of the large variation of each patient’s body habitus due to age, it can be difficult to predict the puncture depth to reach either the epidural or intrathecal spaces (Arthurs et al., 2008). Furthermore, loss-of-resistance technique to identify the epidural space can be further challenged in neonates by the less fibrous tissue planes limiting tactile feedback. Finally, although it is generally agreed to be safe to perform regional anesthesia in anesthetized children, there is some inherent risk associated with performing blocks in cases when there is a limited ability to receive subjective warning signs (e.g., paresthesia) of neural damage (McCormack, 2008). Anatomically based ultrasound is one of the most exciting advances in technology in relation to pediatric regional anesthesia. The use of ultrasound in neuraxial anesthesia in adults is somewhat limited because of the reduced visibility of the spinal canal resulting from poor ultrasound beam penetration through the ossified bony vertebral column. In theory, ultrasound could be of much greater value in the young pediatric population where there is limited ossification, thus allowing good visual resolution of the anatomy and block-related equipment or solutions (Tsui and Suresh, 2010).