NMS. Surgery

22

Part I ♦ Foundations 2. Obtain an abdominal radiograph to determine proper tube placement prior to starting tube feeds for tubes placed at bedside. 3. Post-pyloric placement (jejunostomy, nasoduodenal, nasojejunal) is associated with earlier tolerance. 4. Early initiation of enteral nutrition (<48 hours) is associated with fewer complications and should be used even in the immediate postoperative period following abdominal surgery or trauma. C. Administration rate: Enteral nutrition should be started as continuous infusion. 1. Start full strength at 20 mL/hr and increased by 20 mL/hr every 6–12 hours. 2. The goal rate is determined by caloric needs and the formulas caloric density. 3. Gastric residual volumes of tube feedings may be checked every 4 hours for excessive residual volumes (>500 mL), even if feedings are post- pyloric. a. If residual volumes are high, then the infusion should be stopped and then resumed after 4 hours. b. If residuals continue to be high, then obstruction should be considered. D. Complications 1. Gastric content aspiration is the most common complication of enteral nutrition. 2. Bloating, mesenteric ischemia (rare), and diarrhea may occur with tube feedings. 3. Inadequate nutritional supplementation caused by frequent feeding cessation is not. TRUSTED SOURCE American Society for Parenteral and Enteral Nutrition: Enteral Nutrition Resources. Available at https://www.nutritioncare.org/Guidelines_and_Clinical_Resources/ Enteral_Nutrition_Resources/ III. Total Parenteral Nutrition (TPN): TPN allows the provision of adequate nutrition when the GI tract is not usable due to malabsorption, obstruction, fistulas, or anatomic changes. Combined enteral and parenteral administration is sometimes beneficial. A. Formula composition: TPN solutions should contain components of nutritional requirements because other sources may not be available. 1. Carbohydrates: Often as a glucose solution provide ~50% of total calories and impart a high osmolality to TPN; peripheral parenteral nutrition (PPN) contains lower concentration of glucose and is not significantly hyperosmolar. 2. Amino acids: Provide ~10% of total calories and importantly provide essential amino acids for metabolism.