Hyperammonemia in the newborn often leads to severe fatal illness associated with hyperammonemic encephalopathy. Transient hyperammonemia in newborns (THAN) is characterized by self-limiting, transient hyperammonemia during the neonatal period. THAN may have favorable long-term outcomes if it is diagnosed early and appropriately managed. However, severe hyperammonemia can develop even in newborns with THAN, which may require emergent management. Here we report a case of THAN with severe hyperammonemia during the neonatal period that was successfully treated with continuous renal replacement therapy and nitrogen-scavenging medications. Our patient went on to develop normally and has not re-experienced a hyperammonemic episode until 9 months of age without the administration of a protein restricted diet or medications.
Diet, Protein-Restricted ; Humans ; Hyperammonemia ; Infant, Newborn ; Renal Replacement Therapy ; Urea Cycle Disorders, Inborn

Urea cycle disorder (UCD) is a group of inherited metabolic diseases with high disability or fatality rate, which need long-term drug treatment and diet management. Except those with Citrin deficiency or liver transplantation, all pediatric patients require lifelong low protein diet with safe levels of protein intake and adequate energy and lipids supply for their corresponding age; supplementing essential amino acids and protein-free milk are also needed if necessary. The drugs for long-term use include nitrogen scavengers (sodium benzoate, sodium phenylbutyrate, glycerol phenylbutyrate), urea cycle activation/substrate supplementation agents (N-carbamylglutamate, arginine, citrulline), etc. Liver transplantation is recommended for pediatric patients not responding to standard diet and drug treatment, and those with severe progressive liver disease and/or recurrent metabolic decompensations. Gene therapy, stem cell therapy, enzyme therapy and other novel technologies may offer options for treatment in UCD patients. The regular biochemical assessments like blood ammonia, liver function and plasma amino acid profile are needed, and physical growth, intellectual development, nutritional intake should be also evaluated for adjusting treatment in time.
Humans ; Child ; Citrullinemia/drug therapy* ; Urea Cycle Disorders, Inborn/therapy* ; Arginine ; Sodium Benzoate/therapeutic use* ; Liver Transplantation

Rapid ammonia elevation in blood with accompanying mental change should be considered as a true medical emergency. In such a case, action leading to immediate diagnosis and the earliest possible treatment must occur in order to minimize permanent brain damage. Hyperornithinemia- Hyperammonemia-Homocitrullinuria (HHH) syndrome is a rare inborn errors of metabolism and autosomal recessive metabolic disorder caused by a deficiency of the mitochondrial ornithine transporter at the cellular level. Emergency physicians should take account of the possibility of HHH syndrome in patients with unreasonable hyperammonemia coupled with altered mental status. We report a case of a 59-year old man who presented with headache, nausea, vomiting and altered mental status. His serologic test showed hyperornithinemia, hyperammomemia, and homocitrullinuria. He was treated with fluid therapy and hemodialysis. His clinical manifestation improved and he was discharged after hemodialysis
Amino Acid Transport Systems, Basic ; Ammonia ; Brain ; Emergencies ; Fluid Therapy ; Headache ; Humans ; Hyperammonemia ; Metabolism, Inborn Errors ; Nausea ; Ornithine ; Renal Dialysis ; Serologic Tests ; Urea Cycle Disorders, Inborn ; Vomiting

Amino Acid Transport Systems, Basic ; genetics ; Brain Diseases ; diagnosis ; etiology ; Child ; DNA Mutational Analysis ; Diet, Protein-Restricted ; Female ; Humans ; Hyperammonemia ; complications ; diagnosis ; diet therapy ; genetics ; Ornithine ; deficiency ; genetics ; Recurrence ; Severity of Illness Index ; Urea Cycle Disorders, Inborn ; complications ; diagnosis ; diet therapy ; genetics