Nutrition Support and Enteral/Parenteral Feeding
This domain tests when to use enteral nutrition versus parenteral nutrition, how to start and advance feeds, and how to monitor for complications.
Core rules
- Enteral nutrition is preferred when the gut works. Gastric feeding is first-line; post-pyloric feeding is considered for aspiration risk or delayed gastric emptying.
- Start low and advance based on tolerance, output, and clinical stability. Preterm infants may receive trophic feeds before advancement.
- Parenteral nutrition is for GI failure, short bowel, severe malabsorption, or when enteral feeding is unsafe or insufficient. Hyperosmolar PN requires central access.
- Monitor glucose, electrolytes, triglycerides, liver enzymes, and growth. Refeeding syndrome risk is higher with low BMI, poor intake, malabsorption, or chronic illness; check phosphorus, potassium, and magnesium and give thiamine when indicated.
Worked example
A malnourished adolescent with cerebral palsy is admitted with poor oral intake. Start enteral feeds at a low rate, advance gradually, and check phosphorus, potassium, and magnesium in the first 1–3 days. If phosphorus falls, replace electrolytes and slow advancement rather than continuing rapid escalation.
Traps
Advancing feeds too quickly; forgetting thiamine in refeeding risk; using PN when enteral nutrition is feasible; overlooking line sepsis; not reassessing tolerance and growth.