CDR Enteral and Parenteral Nutrition 2 — Questions and Answers
Question 1: A patient receiving continuous enteral nutrition through a PEG tube develops diarrhea. Which intervention should be tried FIRST?
- Switch to an elemental formula immediately
- Slow the infusion rate and check for infectious causes (Correct answer)
- Discontinue enteral nutrition and start TPN
- Add a fiber supplement to the formula
Correct answer: Slow the infusion rate and check for infectious causes
The first step is to slow the infusion rate and evaluate for infectious causes (such as C. difficile), medication-related causes, or formula intolerance before changing formula type or route.
Question 2: Which amino acid becomes conditionally essential during severe metabolic stress such as critical illness or major surgery?
- Alanine
- Glutamine (Correct answer)
- Serine
- Aspartate
Correct answer: Glutamine
Glutamine becomes conditionally essential during critical illness because demand exceeds endogenous production; it serves as the primary fuel for enterocytes and immune cells and helps maintain gut barrier integrity.
Question 3: What is the recommended protein goal (g/kg/day) for a critically ill adult patient without renal failure receiving nutrition support?
- 0.4–0.6 g/kg/day
- 0.8–1.0 g/kg/day
- 1.2–2.0 g/kg/day (Correct answer)
- 2.5–3.5 g/kg/day
Correct answer: 1.2–2.0 g/kg/day
ASPEN and SCCM guidelines recommend 1.2–2.0 g/kg/day of protein for critically ill adults to support wound healing, immune function, and minimize lean muscle loss during hypermetabolism.
Question 4: Which method of enteral nutrition delivery is most appropriate for a patient who cannot tolerate bolus feedings due to delayed gastric emptying?
- Bolus feeding every 4 hours
- Continuous infusion over 24 hours (Correct answer)
- Intermittent gravity drip feeding
- Cyclic nocturnal feeding
Correct answer: Continuous infusion over 24 hours
Continuous infusion delivers formula at a slow, steady rate around the clock, minimizing the volume in the stomach at any given time and reducing risk of aspiration and intolerance in patients with delayed gastric emptying.
Question 5: A TPN solution containing dextrose, amino acids, and lipids in a single bag is called:
- Piggyback solution
- Total nutrient admixture (TNA) or 3-in-1 solution (Correct answer)
- Standard dual-chamber bag
- Hypertonic dextrose solution
Correct answer: Total nutrient admixture (TNA) or 3-in-1 solution
A total nutrient admixture (TNA), also called a 3-in-1 or all-in-one solution, combines dextrose, amino acids, and lipid emulsion in a single bag for convenient administration.
Question 6: Which electrolyte must be added to parenteral nutrition formulations to prevent its deficiency-related complication of cardiac arrhythmias in patients who are NPO?
- Sodium
- Potassium (Correct answer)
- Calcium
- Magnesium
Correct answer: Potassium
Potassium is critical to add to PN formulations because hypokalemia is common in NPO patients and can cause life-threatening cardiac arrhythmias, particularly ventricular fibrillation.
Question 7: What is the primary purpose of heparin added to parenteral nutrition solutions?
- Prevent bacterial growth in the solution
- Reduce risk of catheter occlusion and thrombosis (Correct answer)
- Stabilize lipid emulsion particles
- Prevent hyperglycemia
Correct answer: Reduce risk of catheter occlusion and thrombosis
Low-dose heparin is sometimes added to PN solutions primarily to help prevent catheter-related thrombosis and occlusion by inhibiting fibrin formation on the catheter tip.
CDR Enteral and Parenteral Nutrition 2
A patient receiving continuous enteral nutrition through a PEG tube develops diarrhea.
Which intervention should be tried FIRST?