Individuals with PROP, at initial presentation or during illnesses, typically present with dehydration, hyperammonemia, and metabolic acidosis.  They require aggressive management that includes removing the toxic organic acids that have accumulated due to the metabolic block, minimizing protein catabolism, and promoting anabolism. Continuous hemofiltration has been used for rapid removal of toxins and allowing administration of larger volumes of fluids without risk of over hydration. Insulin has been administered to increase glucose tolerance.  Gradual rehydration with energy sources administered intravenously in amounts typically exceeding maintenance requirements, has helped to achieve an anabolic state prior to restarting oral intake.

Regular monitoring of clinical and nutritional status to determine adequacy of nutrient intake, and to guide appropriate modifications in the dietary prescription, is central to management of individuals with PROP.  Specific dietary recommendations and interventions are greatly influenced by the individual’s present clinical status, illness, failure to thrive, hypotonia, decreased mobility, and delayed feeding skills.  The main goal is to adjust nutrient intake to assure normal growth, and positive clinical and patient-reported outcomes. Challenges to achieving adequate medical and nutrition management include risk of infection, metabolic crises, vomiting, anorexia and other co-morbidities.  Despite these challenges, reports have shown that early and aggressive medical and nutrition management, typically requiring both parenteral and enteral nutritional support with use of medical foods limited in propiogenic amino acids, can result in improved survival and clinical outcomes. 

Definitions of the protein terminology used throughout this guideline are listed in Appendix B.