General anesthesia in a patient with citrullinemia using Precedex as an adjunct to prevent delayed emergence

Citrullinemia type I is a rare autosomal recessive genetic condition that causes reduced activity of the enzyme, argininosuccinate synthase, which is needed for proper urea metabolism. The end result is hyperammonemia which can cause life-threatening neurologic symptoms and global developmental delay. Previous case reports of the anesthetic management of patients with citrullinemia describe delayed recovery possibly related to elevated ammonia levels postoperatively or choice of intraoperative anesthetics which have included narcotics. In this case report, we present the anesthetic management of a 16-year-old adolescent girl with citrullinemia type I undergoing a vagus nerve stimulator revision. We used the α-2-adrenergic agonist, dexmedetomidine, as an adjunct to avoid narcotics to prevent delayed emergence. She was admitted for hydration the night before the procedure and had a baseline ammonia level of 33 μmol/L (reference, 9-33 μmol/L). Anesthetic maintenance consisted of 2% sevoflurane, dexmedetomidine 0.5 μg/kg per hour, and intravenous acetaminophen given toward the conclusion of the surgery. The patient awoke immediately at the end of the procedure and was extubated in the operating room. Postprocedure, her ammonia level was less than 9 μmol/L. She appeared to be free of pain, was tolerating gastric tube feeds postprocedure, and was discharged to home on the day of surgery. Effective management of ammonia levels in this patient using preoperative hydration and dexmedetomidine as an adjunct to general anesthesia may have helped to prevent delayed emergence.