Pediatric lower limb peripheral nerve blocks: Indications, effectiveness, and the incidence of adverse events

Aim While the proportion of pediatric anesthetics with regional anesthesia in pediatric patients has steadily increased, there are only a few series that describe the use of lower limb peripheral nerve blocks in children. Our aim was to describe the indications, anesthetic approach, and complications associated with lower limb blocks in children undergoing orthopedic surgery in a center with a large caseload of complex patients. Methods In a retrospective analysis of prospectively collected data, we reviewed children who had a peripheral nerve block for orthopedic surgery placed between January 2016 and January 2021 at the Royal Children's Hospital Melbourne. Block data were sourced from the electronic medical record and departmental regional anesthesia database. Data collected included demographics, the site of catheter placement and technique of nerve block, presence of sensory/motor blockade, the use of perioperative opioids, and any complications related to peripheral nerve block. Results A total of 1438 blocks were performed in 1058 patients. Four patients had clinical features of perioperative neurological injury giving an incidence of 3 per 1000 blocks (95% CI 1.1-8:1000). Only one patient had a sensory deficit persisting longer than 6 months for an incidence of 0.8 per 1000 blocks (95% CI 0.1-5:1000). All four peripheral nerve injury followed tibial osteotomy for lengthening procedures or correction of tibial torsion. The etiology of the injury could not be determined despite imaging and surgical exploration and the contribution of popliteal sciatic nerve block to the subsequent PNI could not be confirmed. There were no cases of local anesthetic systemic toxicity. Conclusion An increased risk of perioperative peripheral nerve injury is associated with pediatric tibial osteotomy for congenital deformity. While popliteal sciatic nerve block was not directly implicated in the nerve injury the presence of a prolonged sensory block can delay early recognition and treatment of peripheral nerve injury.