Continuous arteriovenous hemodiafiltration in the acute treatment of hyperammonaemia due to ornithine transcarbamylase deficiency

Background. Acute hyperammonemia caused by urea cycle disorder is a medical emergency for which immediate managements should be taken to minimize permanent brain damage. Among different enzyme defects, ornithine transcarbamylase deficiency (OTC) is one of the most common enzyme defect in urea cycle disorders. We utilized continuous renal replacement therapy techniques in the acute treatment of hyperammonemia due to ornithine transcarbamylase deficiency. Patients and methods. Three male neonates with elevated serum ammonia levels were shown, based on urine organic acid analysis and serum amino acid studies, to have OTC deficiency. Administration of sodium benzoate and sodium phenylacetate for activating alternative nitrogen waste pathway were used associated with protein restriction. Other modalities, including blood exchange transfusion, peritoneal dialysis, continuous renal replacement therapy were utilized in an attempt to lower serum ammonia concentration. Results. We report the successful use of continuous arteriovenous hemofiltration (CAVH), continuous arteriovenous hemodialysis (CAVHD), continuous arteriovenous hemodiafiltration (CAVHDF) in the acute management of hyperammonemia due to OTC deficiency. We also compared the ammonia clearance between peritoneal dialysis, exchange transfusion, CAVH, CAVHD and CAVHDF. It demonstrated the evidence that CAVHDF provides the best ammonia clearance. Conclusion. Continuous renal replacement therapy including CAVH, CAVHD, and CAVHDF may be the alternative techniques for acute management of hyperammonemia in inborn error of metabolism when dialysis machine is not available. Our data suggests CAVHDF provides the best ammonia clearance.