title: Ultrasound visibility of spinal structures and local anesthetic spread in children undergoing caudal block.
abstract: This study assessed ultrasound visibility of spinal structures in children and observed the extent of local anesthetic spread within the epidural space during caudal block. Spinal structures were evaluated with ultrasound from the sacral area to the thoracic area in 80 children, and drug spread levels were observed after caudal injection of 0.5, 1.0, 1.25 and 1.5 mL/kg local anesthetic. The conus medullaris, dural sac and dura mater were easily identified with ultrasound in most children. However, ligamentum flavum visibility declined with increasing vertebral level and markedly decreased at the thoracic level in children older than 7 mo or heavier than 8.5 kg. Drug spread was higher with increasing volume (p < 0.001) and in children ≤12 mo more than children >12 mo (p < 0.001); drug spread was significantly correlated with age (R(2) = 0.534). Spread levels assessed with ultrasound were roughly two to three segments lower than those in previous radiologic studies.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea; Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Seokyung
authors.initials: S
authors.lastname: Shin
authors.affiliation: Department of Anesthesiology and Pain Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea; Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Ji Young
authors.initials: JY
authors.lastname: Kim
authors.affiliation: Department of Anesthesiology and Pain Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea; Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Won Oak
authors.initials: WO
authors.lastname: Kim
authors.affiliation: Department of Anesthesiology and Pain Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Seung Hyun
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Department of Anesthesiology and Pain Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea; Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Korea. Electronic address: hkkil@yuhs.ac.
authors.forename: Hae Keum
authors.initials: HK
authors.lastname: Kil
mesh_terms: D000763:Anesthesia, Caudal / Q000379:methods*; D000779:Anesthetics, Local / Q000493:pharmacokinetics*; D002675:Child, Preschool; D004305:Dose-Response Relationship, Drug; D004388:Dura Mater / Q000000981:diagnostic imaging; D004824:Epidural Space / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D011446:Prospective Studies; D013131:Spine / Q000000981:diagnostic imaging*; D014463:Ultrasonography
chemical_list: D000779:Anesthetics, Local
keywords: Caudal block; Children; Spinal structures; Ultrasound