Epidural catheter placement in children:: comparing a novel approach using ultrasound guidance and a standard loss-of-resistance technique

Background. We report a prospective, randomized study to evaluate ultrasound guidance for epidural catheter placement in children 0-6 yr of age. Methods. Epidural catheters were placed at lumbar or thoracic cord levels in 64 children undergoing major surgery, using either ultrasonography or loss-of-resistance (LOR) for guidance. Using a 5-10 MHz linear ultrasound probe, the neuraxial structures were identified, the skin-epidural depth and epidural space was measured, the advancing epidural catheter visualized, and the spread of local anaesthetic verifying catheter position was confirmed. Epidural placement procedures were analysed for bone contacts and speed of execution. Children under 6 months were analysed separately. Results. Epidural placement involved bone contacts in 17% of children in the ultrasound group and 71% of children in the LOR group (P < 0.0001). Epidurals were executed more swiftly in the ultrasound group [162 (75) s vs 234 (138) s; P < 0.01]. Children under 6 months revealed a 0.9 correlation between skin-epidural depth and body weight. Conclusions. Ultrasonography is a useful aid to verify epidural placement of local anaesthetic agents and epidural catheters in children. Advantages include a reduction in bone contacts, faster epidural placement, direct visualization of neuraxial structures and the spread of local anaesthetic inside the epidural space. Ultrasound guidance requires additional training and good manual skills, and should only be used once experience in ultrasound-guided techniques of regional anaesthesia has been acquired.