Establish Nutrition Prescriptions for Energy and Protein Intakes

1. Individualize energy and protein goals based on age, disease severity, growth, and clinical status. See TABLE #1, Total Protein and Energy Recommendations for Individuals with Urea Cycle Disorders When Well

2. Prescribe the highest protein goal an individual can tolerate, generally 0.8-1.5 g/kg/day.

3. Individuals with mild UCDs typically tolerate a protein-controlled diet¹ or an unrestricted protein diet.

¹ Protein-controlled diet: a diet that provides at least the DRI from intact protein but does not allow for unrestricted amounts of protein and may or may not include EAA-based medical food.

Protein Source

1. In severe UCD, use EAA-based medical food to meet approximately 50% of total protein needs and titrate up or down as clinically indicated. See TABLE #1, Total Protein and Energy Recommendations for Individuals with Urea Cycle Disorders When Well. 

2. In mild UCD, use of EAA-based medical food is generally not required to maintain metabolic stability. 

3. In individuals with ARG, provide approximately 50% of total protein as intact protein and titrate based on plasma arginine concentrations, proportionately adjusting EAA-based medical food as needed. 

4. For individuals who failed a trial of EAA-based medical food and who exhibit low plasma EAAs, consider strategic introduction of up to 50% of the total protein goal from high biological value protein sources. 

For infants with UCD, use human milk as a source of intact protein when possible.

1. For infants with mild or severe UCD, use human milk, if available, as a sole or primary protein source with close monitoring of intake and lactation support. 

2. For infants with severe UCD, consider using expressed human milk to ensure protein goals are consistently met. 

3. Provide recommendations for use of supplemental standard infant formula and/or protein-free formula when needed. 

Use tube feedings when appropriate for supplemental intake of nutrients, fluid, or to administer medications.

1. Consider long-term enteral feeding support in individuals with severe UCDs who experience persistent poor oral intake, particularly during early childhood, or when enteral access is needed to ensure consistent delivery of medications.

2. Refer individuals requiring enteral feeding to feeding specialist(s) for behavioral feeding support and oral skill development.

Meet the age-appropriate DRI for intake of fluids, vitamins, and minerals and consider supplementation when insufficient intake is determined. 

1. Regularly assess intake of micronutrients (e.g., calcium, copper, iron, selenium, vitamins B12 and D, and zinc) and essential fatty acids. Provide micronutrient or conditionally essential nutrient supplementation as needed based on dietary assessment and biochemical results. 

2. Ensure adequate fluid intake (e.g., at least 1.5 ml/kg/day for infants and 1.0 ml/kg/day for older children). 

Consider additional precautions for planned procedures requiring anesthesia and/or prolonged fasting.

1. Coordinate scheduling of planned procedures as the first case of the day, and arrange admission the day prior to the procedure for appropriate monitoring and management.

2. Minimize fasting (i.e., NPO period) to the shortest duration for surgical safety and administer continuous IV dextrose at an age-appropriate glucose infusion rate, maintained throughout the procedure to prevent catabolism and hyperammonemia.

3. Avoid prolonged fasting, such as religious fasting and fasting during strenuous physical activity.