Continuous venovenous hemodiafiltration in neonatal onset hyperammonemia.

We report on four cases of neonatal-onset hyperammonemia due to metabolic disorders treated with continuous hemodiafiltration (CHDF). CHDF accomplished prompt removal of serum ammonia under very stable circulation. To overcome the various difficulties of blood purification procedures to the neonate, we used: (1) a 7-Fr double lumen catheter from the internal jugular vein to the atrium to perform the procedure veno-venously, (2) a special circuit for neonates, (3) nafamostat mesilate as an anticoagulant, and (4) a circuit warmer. The serum ammonium level decreased under 200 microg/dL within 30 hours and lactic acidosis were corrected immediately. We conclude that CHDF is an extremely effective and safe treatment for fluminant neonatal-onset hyperammonemia due to metabolic disorders.