Maple syrup urine disease: treatment of the acutely ill newborn.

Three patients with maple syrup urine disease were treated during the acute neonatal stage. Multiple exchange transfusions proved to be a satisfactory means of achieving rapid clinical and biochemical improvement during this phase. On the other hand, evidence is provided suggesting that in addition to exchange transfusions, a high calorie intake above 150 Cal/kg body weight/day is necessary to lower the plasma concentration of the branched chain amino acids to near-normal levels. As long as this calorie intake was not provided, further exchange transfusions failed to lower the plasma leucine concentration to below 17 mg/100 ml in one patient. It is assumed that this high calorie intake is necessary to prevent the breakdown of endogenous protein. Treatment of acute episodes in maple syrup urine disease should therefore not only eliminate the elevated alpha-keto acids and branched chain amino acids quickly (i.e. by multiple exchange transfusions or peritoneal dialysis), but in addition should provide a high calorie intake.