Epidural Anesthesia

Abstract

During epidural anesthesia, local anesthetics and adjuvants are administered into the epidural space by a single-shot, intermittent, or continuous technique. Epidural analgesia is used for open thoracic surgery, major intra-abdominal surgery with extensive surgical dissection, major lower extremity surgery, and long-term pain management. Epidural anesthesia is contraindicated in pediatric patients with uncorrected coagulopathy, hemophilia, liver disease causing coagulopathy, skin infection at the insertion site, bacteremia/sepsis, or lack of parental consent. Anesthesiologists should be familiar with the current American Society of Regional Anesthesia and Pain Medicine guidelines regarding anticoagulation and bleeding disorders in the setting of neuraxial anesthesia before performing epidural anesthesia. In infants, the tip of the conus medullaris and dural sac are located lower in the spinal column than in adults. Additionally, because the epidural space contains less fat and fibrous tissue than in adults, in infants it is easier to insert an epidural catheter at a lower level and then to thread it up to a higher level. In infants younger than 6 months, the vertebral column remains cartilaginous, and epidural catheters can be visualized with ultrasonography. In infants, for the initial placement of the needle, there is a more subtle “give” as the ligamentum flavum is pierced than in adult patients. As a general rule, the depth of the epidural space is 1 mm/kg of body weight (e.g., the depth of the epidural space in a 10-kg child would be 10 mm). However, because wide variation exists in the depth of the epidural space, a test for loss of resistance is performed as soon as the epidural needle has entered the supraspinous ligament.