Hour 0–1 Arrange transfer to tertiary care center with appropriate facilities and specialists Establish central vascular access Avoid compromise of potential dialysis sites Intubation and airway stabilization Sedate aggressively to reduce metabolic demand Collect specimens for necessary diagnostic laboratory tests Plasma ammonia Plasma amino acids Urine organic acids Plasma acylcarnitine profile Assemble multidisciplinary team Neonatology Metabolic genetics Nutrition Nephrology Surgery Nursing Alert laboratory team about need for rapid results and frequent assessments Alert pharmacy team about need for specialized medications and nutrition Intravenous fluids/nutrition Stop enteral feeding Intravenous fluids Maximize glucose infusion rate (10% dextrose in water [D10W] or higher) Intralipids (2–3 g/kg/d) Goal of 80–120 kcal/kg/d Medications Urea cycle disorders Sodium phenylacetate/sodium benzoate infusion (250 mg/kg of each as initial bolus then as a continuous daily infusion) Intravenous arginine (200 mg/kg unless AS or AL deficiency suspected, then 400–700 mg/kg) as initial bolus then as a continuous daily infusion Carbamylglutamate 25 mg/kg/dose every 6 hours (if available) Organic acidemias Intravenous carnitine (100 mg/kg/dose every 4–6 hours) Carbamylglutamate 25 mg/kg/dose every 6 hours (if available) Hours 1–12 Begin hemodialysis at maximal flow rates Review diagnostic lab results as available If essential amino acid deficiency is present, consider reintroducing protein sooner to reverse catabolic state Monitor for hypotension Common with hemodialysis May be exacerbated by arginine infusion (nitric oxide donor) May reduce arginine rate if vasodilation/hypotension present Monitor for seizures Intermittent or continuous EEG; treat if present Hours 12–48 Transition from hemodialysis to hemofiltration Monitor for rebound hyperammonemia Laboratory monitoring Electrolytes and ammonia every 6 hours Reintroduce protein Start with 0.5 g protein/kg/d and titrate upward 50% of protein goals from essential amino acids 50% of protein goals from whole protein Enteral route preferred Hours 48 and beyond Nutrition tailored to specific cause of hyperammonemia ∼1.5 g protein/kg/d in neonates Tailor nutrition to specific inborn error of metabolism 50% of protein from disease-specific formula 50% of protein from breast milk or whole-protein formula Assess nutritional parameters (growth, plasma amino acids) frequently Transition intravenous nutrition and medication to enteral Urea cycle disorders: sodium phenylbutyrate 450–600 mg/kg/d Organic acidemias: carnitine 100–200 mg/kg/d Other medications depending on specific cause Assess for neurologic sequelae Brain MRI EEG Developmental assessment Consider ... |