Abstract
Ornithine transcarbamylase (OTC) deficiency is a urea cycle disorder that causes recurrent hyperammonemia from neonatal period. Reducing serum ammonia (NH3) level by renal replacement therapy and nutritional management for correcting the amino acid imbalance are important for treatment in the acute phase of the disease. Here, we report a case of severe hyperammonemia caused by OTC deficiency, for which high-flow continuous hemodiafiltration (high-flow CHDF) was effective although all the conventional treatments, including renal replacement therapy, had failed. The patient was a twenties-year-old man with OTC deficiency who was diagnosed with recurrent hyperammonemia at one year of age. He lost consciousness with no known trigger and was admitted to another hospital with a diagnosis of hyperammonemia attack. Serum NH3 level remained extremely high after all the conventional treatments, including protein restriction and renal replacement therapy. He was transferred to our hospital on the 10th day. high-flow CHDF (dialysis flow rate 9 l/hr) was initiated 2 days after the admission. Serum NH3 level decreased soon, and he regained consciousness. Renal replacement therapy was discontinued on the 32nd day, and orthotopic liver transplantation was successfully performed on the 67th day.
