Total parenteral nutrition therapy of toxic maple syrup urine disease

Abstract

Maple Syrup Urine Disease (branched-chain a-ketoacid dehydrogenase deficiency) in a neonate who was too ill to feed was successfully treated with total parenteral nutrition which promoted protein synthesis thereby allowing accumulated branched-chain amino acids to be incorporated into body protein. Total parenteral nutrition was initiated after the patient was unable to continue nasogastric feeding and peritoneal dialysis had failed due to the patient's hypotonia. A special total parenteral nutrition mixture lacking leucine, isoleucine, and valine was supplemented with Intralipid to provide an average of 125 kcal/kg/day. Nitrogen balance documented a normal nitrogen retention rate of 185 mg N/kg/day. The various branched-chain amino acids were added individually to the intravenous solution as the plasma concentration of each decreased. The intake of the branched-chain amino acids (isoleucine 65 mg/kg/day, valine 78 mg/kg/day, and leucine 159 mg/kg/day) was approximately two-thirds of that of the normal breast-fed infant, equivalent to the normal rate of incorporation of these essential amino acids into protein. Total parenteral nutrition achieves and sustains branched-chain amino acids removal efficiently with fewer risks than multiple exchange transfusions or peritoneal dialysis. A combination of total parenteral nutrition with one of these alternative modes of therapy may be most useful in the acutely toxic patient.