Enteral Nutrition Formulations, Administration, and Monitoring
Formulation choices
Standard polymeric formulas suit most patients with a functional gut. Elemental/semi-elemental formulas are considered for severe malabsorption, short bowel, or pancreatitis with intolerance. Disease-specific formulas (renal, hepatic, pulmonary, diabetic) have limited evidence; questions often test that standard formulas are usually adequate. Fiber-containing formulas may help with diarrhea or constipation but are avoided in strict fluid restriction or certain obstructions. Know calorie density (1.0, 1.2, 1.5, 2.0 kcal/mL) and protein content when matching to fluid-restricted patients.
Administration
Delivery methods: bolus (intermittent, gravity), cyclic (nocturnal), and continuous. Continuous is preferred for critically ill, jejunal feeding, and poor tolerance. Start at low rate and advance as tolerated. Head-of-bed elevation 30-45°, checking residuals per policy (not mandatory in all settings), and flushing the tube are key practices.
Monitoring
Track tolerance (nausea, distension, diarrhea), electrolytes, glucose, and weight. Refeeding syndrome risk (low phosphate, potassium, magnesium) requires slow initiation and electrolyte monitoring. Aspiration risk warrants post-pyloric access and elevated head of bed.
Worked rule of thumb
For a 70 kg patient needing 1.5 g/kg protein = 105 g/day. If using a 1.0 kcal/mL formula with 40 g protein/L at 1500 mL/day, protein = 60 g - insufficient; consider a higher-protein formula or supplement.