Chapter 42: Nutritional Supplements & Parenteral Nutrition

Nutritional Supplements & Parenteral Nutrition pharmacology chapter details the critical science of nutritional support and pharmaconutrition, addressing how metabolic processes like anabolism and catabolism rely on adequate nutrient intake to prevent conditions such as malnutrition. The text thoroughly examines two primary delivery methods: Enteral Nutrition (EN), which utilizes the GI tract (either orally or via various tube feeding routes like nasogastric or gastrostomy), and Parenteral Nutrition (PN), also called Total Parenteral Nutrition (TPN), which delivers nutrients intravenously, bypassing the digestive system entirely. The sources describe several types of enteral formulations, categorized by chemical complexity, including elemental formulations (requiring minimal digestion), polymeric formulations (closely resembling normal food intake, like Ensure), modular formulations (single-nutrient supplements for carbohydrates, fats, or proteins), and altered amino acid formulas (tailored for specific metabolic disorders). While EN is the preferred route due to advantages such as maintaining gut integrity, associated adverse effects include GI intolerance, osmotic diarrhea, and the risk of aspiration pneumonia or dumping syndrome. TPN is indicated when the GI tract is non-functional and involves the administration of basic components: amino acids (for protein synthesis), dextrose (the main carbohydrate calorie source), and lipid emulsions (supplying essential fatty acids and energy). Delivery routes for TPN are classified as Peripheral TPN (temporary, lower dextrose concentration, often less than 14 days) and Central TPN (prolonged use, higher dextrose concentration, greater risk of infection/sepsis). Key nursing responsibilities are highlighted across the nursing process, emphasizing the importance of comprehensive nutritional assessment (including laboratory values like albumin and total protein), proper checking of enteral tube placement (via pH testing or X-ray) and gastric residual volumes, careful monitoring for adverse effects like phlebitis with peripheral TPN, and vigilant management of metabolic complications such as hyperglycemia or hypoglycemia associated with high dextrose concentrations in TPN.