Regional analgesia in the pediatric population allows for both excellent postoperative analgesia and attenuation of the stress response in infants and children. Epidural anesthesia can decrease the need for postoperative ventilatilatory support after trachesophageal fistula repair and reduce the complications and costs following open fundoplication. Since the 1990s, there has been a trend towards utilizing regional techniques for children undergoing surgery. Placement of a regional block after the induction of general anesthesia allows for optimal postoperative pain control and the ability to reduce levels of general anesthesia intraoperatively. Several important differences exist in children undergoing regional blocks: the target nerves are smaller, closer to corresponding vessels, and much closer to the skin verses the adult population. Additionally, clinically relevant sympathectomy with neuraxial techniques are rare in children younger than eight years old. The potential for local anesthetic toxicity is greater in infants due to reduced levels of 1-glycoprotein levels and therefore increased levels of the non-protein bound fraction of local anesthetic.
Blocks that are used most frequently are: Rectus sheath block (here the thoracic intercostal nerve is blocked which is responsible for sensation along the anterior abdominal wall – most often used for repair of an umbilical hernia). Illioinguinal nerve block (placed 1-2 cm medial and inferior to the ASIS and depositing local anesthetic into the fascia – used for hernia repairs or orchidopexy). Femoral nerve block (for femur fractures or the need for quadriceps muscle biopsies). Caudal block (employed for operations below the level of the diaphragm – placed by advancing a 22- or 23- gauge needle into the sacrococcygeal ligament between the two sacral cornua).
The utility of regional anesthesia for pediatric cardiac surgery has recently been investigated. Single doses of intrathecal opioids with or without local anesthetic, or continuous spinal anesthesia using a microcatheter technique appear particularly promising for open heart surgery. Epidural or paravertebral techniques seem best suited for closed procedures. The major concern with these techniques is that of local bleeding at the site of subarachnoid or epidural puncture in a heparinized child.
As in the adult population, complications with pediatric regional techniques are uncommon. A large prospective one-year survey of more than 24,000 pediatric regional anesthetics found an overall incidence of complications of 0.9 in 1000 blocks, with no complications of peripheral techniques. The most common complications were either failure to establish a block or failure of block maintenance. Failure of establishment of adequate neuraxial blockade in babies may be at least in part due to the significant variability of anesthetic spread. Radiological assessment of contrast injected through epidural catheters in babies (1.8–4.5 kg) after major surgery found that both the quality and extent of spread were different for every baby. Filling defects and ‘skipped’ segments were common. Spread was more extensive after 1 ml/kg compared with 0.5 ml/kg — but not twice as great — with fewer ‘skipped’ segments and greater density of dye.
Polaner et al. Pediatric Regional Anesthesia Network (PRAN): a multi-institutional study of the use and incidence of complications of pediatric regional anesthesia. Anesth. Analg.: 2012, 115(6);1353-64
P-A Lönnqvist, N S Morton Postoperative analgesia in infants and children. Br J Anaesth: 2005, 95(1);59-68