MCQ Quiz: Total Parenteral Nutrition

Total Parenteral Nutrition (TPN) is a complex, life-sustaining intravenous therapy that provides complete nutritional support to patients who are unable to use their gastrointestinal tract. The pharmacist plays a central and critical role on the nutrition support team, responsible for everything from calculating a patient’s specific macronutrient and electrolyte needs to ensuring the sterile compounding of these complex admixtures is safe and stable. As detailed in the sterile compounding, patient care, and skills lab curricula, a deep understanding of TPN is essential. This quiz will test your knowledge on the fundamental principles, calculations, compounding procedures, and clinical management of Total Parenteral Nutrition.

1. Total Parenteral Nutrition (TPN) is indicated for a patient who:

• a) Has a functioning gastrointestinal (GI) tract but prefers not to eat.
• b) Is unable to meet their nutritional needs via the GI tract for an extended period (e.g., > 7 days).
• c) Needs short-term fluid hydration only.
• d) Requires a clear liquid diet.

Answer: b) Is unable to meet their nutritional needs via the GI tract for an extended period (e.g., > 7 days).

2. A major advantage of using enteral nutrition (“tube feeding”) over parenteral nutrition when the gut is functional is that enteral nutrition:

• a) Is more expensive.
• b) Carries a higher risk of bloodstream infections.
• c) Helps maintain gut integrity and reduces the risk of bacterial translocation.
• d) Provides more calories per milliliter.

Answer: c) Helps maintain gut integrity and reduces the risk of bacterial translocation.

3. TPN administered through a peripheral vein (PPN) must have a final osmolarity of less than what value to prevent phlebitis?

• a) 300 mOsm/L
• b) 600 mOsm/L
• c) 900 mOsm/L
• d) 1800 mOsm/L

Answer: c) 900 mOsm/L

4. What are the three macronutrients that provide calories in a TPN formulation?

• a) Amino acids, electrolytes, and vitamins.
• b) Dextrose, sterile water, and trace elements.
• c) Dextrose, amino acids, and intravenous fat emulsion (IVFE).
• d) Lipids, heparin, and insulin.

Answer: c) Dextrose, amino acids, and intravenous fat emulsion (IVFE).

5. How many kcal/gram does intravenous dextrose provide?

• a) 9 kcal/g
• b) 7 kcal/g
• c) 4 kcal/g
• d) 3.4 kcal/g

Answer: d) 3.4 kcal/g

6. A TPN formulation contains 500 mL of 10% amino acids. How many grams of protein is the patient receiving from this component?

• a) 10 grams
• b) 50 grams
• c) 100 grams
• d) 500 grams

Answer: b) 50 grams

7. A 20% intravenous fat emulsion (IVFE) provides how many kcal/mL?

• a) 1.1 kcal/mL
• b) 2 kcal/mL
• c) 3.4 kcal/mL
• d) 9 kcal/mL

Answer: b) 2 kcal/mL

8. What is the primary source of carbohydrates in a TPN solution?

• a) Fructose
• b) Sucrose
• c) Dextrose
• d) Lipids

Answer: c) Dextrose

9. To prevent calcium and phosphate precipitation during TPN compounding, which of the following is a critical step?

• a) Add calcium and phosphate salts back-to-back at the beginning of the mixing process.
• b) Add the phosphate salt early in the mixing sequence and the calcium salt near the end.
• c) Use only calcium chloride because it is less reactive.
• d) Mix the TPN at a very warm temperature.

Answer: b) Add the phosphate salt early in the mixing sequence and the calcium salt near the end.

10. “Cracking” or “creaming” of a TPN admixture refers to the destabilization of which component?

• a) Amino acids
• b) Dextrose
• c) Intravenous fat emulsion
• d) Electrolytes

Answer: c) Intravenous fat emulsion

11. The Glucose Infusion Rate (GIR) should not exceed what rate in adults to prevent hyperglycemia and hepatic steatosis?

• a) 1-2 mg/kg/min
• b) 4-5 mg/kg/min
• c) 8-10 mg/kg/min
• d) 12-15 mg/kg/min

Answer: b) 4-5 mg/kg/min

12. A patient develops refeeding syndrome after the initiation of TPN. Which electrolyte abnormality is a hallmark of this condition?

• a) Hypernatremia
• b) Hypercalcemia
• c) Hypophosphatemia
• d) Hypokalemia

Answer: c) Hypophosphatemia

13. Which of the following is a standard component of a daily multivitamin infusion for TPN?

• a) Vitamin K
• b) Vitamin C
• c) Thiamine
• d) All of the above are typically included in standard adult MVI products.

Answer: d) All of the above are typically included in standard adult MVI products.

14. A patient on long-term TPN is at risk for developing metabolic bone disease due to:

• a) Inadequate calcium and phosphate provision.
• b) Potential for aluminum contamination in TPN components.
• c) Altered vitamin D metabolism.
• d) All of the above.

Answer: d) All of the above.

15. What size filter is recommended for the administration of a 2-in-1 TPN solution (dextrose and amino acids)?

• a) 0.22 micron
• b) 1.2 micron
• c) 5 micron
• d) No filter is needed.

Answer: a) 0.22 micron

16. For a 3-in-1 TPN admixture (total nutrient admixture), what size filter is required?

• a) 0.22 micron
• b) 1.2 micron
• c) 5 micron
• d) No filter is needed.

Answer: b) 1.2 micron

17. A common complication of TPN therapy that requires regular monitoring of liver function tests (LFTs) is:

• a) TPN-associated liver disease (cholestasis).
• b) Acute pancreatitis.
• c) Gastroparesis.
• d) Constipation.

Answer: a) TPN-associated liver disease (cholestasis).

18. Regular insulin is often added to a TPN bag to manage:

• a) Hypoglycemia
• b) Hypertriglyceridemia
• c) Hyperglycemia
• d) Acidosis

Answer: c) Hyperglycemia

19. Which of the following is a major risk associated with central venous access for TPN administration?

• a) Phlebitis
• b) Catheter-related bloodstream infection (CRBSI).
• c) Infiltration.
• d) Muscle soreness.

Answer: b) Catheter-related bloodstream infection (CRBSI).

20. When transitioning a patient from TPN to enteral nutrition, the TPN infusion rate should be:

• a) Increased to prevent hypoglycemia.
• b) Stopped abruptly once the first tube feed is given.
• c) Tapered down slowly as the enteral nutrition rate is advanced to prevent rebound hypoglycemia.
• d) Kept the same for at least 72 hours.

Answer: c) Tapered down slowly as the enteral nutrition rate is advanced to prevent rebound hypoglycemia.

21. A standard bag of amino acids contains essential amino acids (EAAs) and non-essential amino acids (NEAAs). In some pediatric or stress formulations, which amino acid might be added as it is considered “conditionally essential”?

• a) Glycine
• b) Alanine
• c) Glutamine
• d) Leucine

Answer: c) Glutamine

22. A pharmacist receives a TPN order with 80 mEq of calcium gluconate and 40 mmol of potassium phosphate. The pharmacist’s first concern should be:

• a) The high potassium content.
• b) The risk of calcium-phosphate precipitation.
• c) The high sodium content.
• d) The cost of the ingredients.

Answer: b) The risk of calcium-phosphate precipitation.

23. As outlined in the skills lab, understanding TPN order sets is a key objective. What does “2-in-1” refer to?

• a) Dextrose and lipids are in one bag; amino acids are separate.
• b) Dextrose and amino acids are in one bag; lipids are infused separately.
• c) Amino acids and lipids are in one bag; dextrose is separate.
• d) Two separate bags are used for a 12-hour infusion.

Answer: b) Dextrose and amino acids are in one bag; lipids are infused separately.

24. Which of the following is a common monitoring parameter for a patient on TPN?

• a) Daily body weight.
• b) Blood glucose levels every 6 hours.
• c) A basic metabolic panel (electrolytes) daily until stable.
• d) All of the above.

Answer: d) All of the above.

25. A patient on TPN develops a fever, chills, and an elevated white blood cell count. The team’s immediate concern should be:

• a) A drug-drug interaction.
• b) An electrolyte abnormality.
• c) A catheter-related bloodstream infection (CRBSI).
• d) Hyperglycemia.

Answer: c) A catheter-related bloodstream infection (CRBSI).

26. Why are trace elements included in a TPN formulation?

• a) To provide extra calories.
• b) To prevent deficiency syndromes, as they are cofactors for many enzymatic reactions.
• c) To improve the stability of the solution.
• d) To adjust the pH of the admixture.

Answer: b) To prevent deficiency syndromes, as they are cofactors for many enzymatic reactions.

27. A patient on long-term TPN without lipids is at risk for developing:

• a) Vitamin C deficiency.
• b) Essential fatty acid deficiency (EFAD).
• c) Iron deficiency anemia.
• d) Protein overload.

Answer: b) Essential fatty acid deficiency (EFAD).

28. What is the caloric value of 1 gram of protein from an amino acid solution?

• a) 3.4 kcal/g
• b) 4 kcal/g
• c) 7 kcal/g
• d) 9 kcal/g

Answer: b) 4 kcal/g

29. The “PPCP and Stepwise Approach” to parenteral nutrition, as taught in Patient Care VIII, involves:

• a) Assessing the patient’s nutritional status and needs before writing the TPN order.
• b) Dispensing the TPN without reviewing the patient’s chart.
• c) Using a standard TPN formula for all patients.
• d) Focusing only on the compounding process.

Answer: a) Assessing the patient’s nutritional status and needs before writing the TPN order.

30. Which trace element is sometimes held from a TPN in a patient with severe cholestatic liver disease?

• a) Zinc
• b) Selenium
• c) Copper and Manganese
• d) Chromium

Answer: c) Copper and Manganese

31. Famotidine or another H2-receptor antagonist is sometimes added to a TPN to:

• a) Provide nutritional value.
• b) Prevent stress-related mucosal damage (stress ulcer prophylaxis).
• c) Lower blood glucose.
• d) Stabilize the lipid emulsion.

Answer: b) Prevent stress-related mucosal damage (stress ulcer prophylaxis).

32. A “total nutrient admixture” (TNA) is also known as a:

• a) 2-in-1 solution
• b) 3-in-1 solution
• c) Peripheral line solution
• d) Dialysis solution

Answer: b) 3-in-1 solution

33. An advantage of using a 3-in-1 TNA system is:

• a) It has a lower risk of precipitation.
• b) It requires only one infusion pump, simplifying administration.
• c) It is easier to visualize precipitates.
• d) It is stable for a longer period of time.

Answer: b) It requires only one infusion pump, simplifying administration.

34. The pharmacist’s role in sterile compounding of TPN includes:

• a) Following aseptic technique during preparation.
• b) Verifying the calculations and the final formulation.
• c) Checking for calcium-phosphate compatibility.
• d) All of the above.

Answer: d) All of the above.

35. A patient on warfarin is started on TPN. The pharmacist should be aware that:

• a) The standard multivitamin injection contains vitamin K, which can decrease the INR.
• b) TPN will always increase the INR.
• c) There is no interaction between TPN and warfarin.
• d) Warfarin should be discontinued.

Answer: a) The standard multivitamin injection contains vitamin K, which can decrease the INR.

36. A patient receiving TPN has triglyceride levels of 450 mg/dL. The appropriate action is to:

• a) Increase the lipid infusion rate.
• b) Hold the intravenous fat emulsion for the day and re-evaluate.
• c) Add more dextrose to the TPN.
• d) Ignore the result as it is not clinically significant.

Answer: b) Hold the intravenous fat emulsion for the day and re-evaluate.

37. Which medication can precipitate in a TPN containing calcium if it is not added correctly?

• a) Heparin
• b) Ceftriaxone
• c) Regular insulin
• d) Famotidine

Answer: b) Ceftriaxone

38. The protein requirement for a critically ill, stressed patient is generally:

• a) Lower than a healthy adult.
• b) The same as a healthy adult.
• c) Higher than a healthy adult (e.g., 1.5-2.0 g/kg/day).
• d) Met by dextrose alone.

Answer: c) Higher than a healthy adult (e.g., 1.5-2.0 g/kg/day).

39. Before starting TPN in a severely malnourished patient, it is critical to:

• a) Administer a large dextrose bolus.
• b) Correct any pre-existing electrolyte abnormalities, especially phosphate, magnesium, and potassium.
• c) Withhold all fluids.
• d) Provide a high-protein diet.

Answer: b) Correct any pre-existing electrolyte abnormalities, especially phosphate, magnesium, and potassium.

40. A key step in calculating a TPN regimen is to first determine the patient’s:

• a) Favorite food.
• b) Insurance provider.
• c) Estimated fluid, energy, and protein needs.
• d) Height from last year.

Answer: c) Estimated fluid, energy, and protein needs.

41. The pH of the TPN admixture is an important factor affecting the solubility of:

• a) Dextrose
• b) Amino acids
• c) Calcium and phosphate
• d) Sodium and potassium

Answer: c) Calcium and phosphate

42. Which of the following is a potential cause of hyperglycemia in a patient on TPN?

• a) Too low of a dextrose infusion rate.
• b) Stress response from critical illness or infection.
• c) Concomitant steroid therapy.
• d) Both B and C.

Answer: d) Both B and C.

43. A TPN order is written for “D10WAA4.25%”. This means the final concentration of dextrose is 10% and the final concentration of amino acids is:

• a) 10%
• b) 4.25%
• c) 8.5%
• d) 15%

Answer: b) 4.25%

44. To minimize the risk of a catheter-related infection, TPN should be administered through:

• a) A peripheral IV line that is also used for blood draws.
• b) A dedicated lumen of a central venous catheter.
• c) The same line as other IV medications.
• d) A line that is changed every week.

Answer: b) A dedicated lumen of a central venous catheter.

45. A patient on TPN for several weeks develops a scaly, eczematous rash. This could be a sign of:

• a) Hyperglycemia
• b) An infusion reaction.
• c) Essential fatty acid deficiency.
• d) A vitamin B12 deficiency.

Answer: c) Essential fatty acid deficiency.

46. The osmolarity of a TPN solution is primarily driven by the concentrations of:

• a) Lipids and water.
• b) Dextrose and amino acids.
• c) Trace elements.
• d) Vitamins.

Answer: b) Dextrose and amino acids.

47. A pharmacist is reviewing a TPN order. This is part of which step in the Pharmacists’ Patient Care Process (PPCP)?

• a) Collect
• b) Assess
• c) Implement
• d) All of the above steps are involved in TPN management.

Answer: d) All of the above steps are involved in TPN management.

48. Why should a TPN infusion be started at a slow rate and gradually titrated up over the first day?

• a) To allow the patient to get used to the taste.
• b) To allow the pancreas to adapt to the glucose load and prevent hyperglycemia.
• c) To save money on the first day.
• d) To make the infusion last longer.

Answer: b) To allow the pancreas to adapt to the glucose load and prevent hyperglycemia.

49. Propofol, an anesthetic agent used for sedation in the ICU, is formulated in a lipid emulsion. This is important for a pharmacist managing a TPN because:

• a) It will interact with the amino acids.
• b) It provides a significant source of calories that must be accounted for in the nutritional plan.
• c) It cannot be given to patients on TPN.
• d) It lowers the patient’s triglyceride levels.

Answer: b) It provides a significant source of calories that must be accounted for in the nutritional plan.

50. The ultimate responsibility for ensuring a TPN formulation is safe, stable, and appropriate for the patient lies with the:

• a) Physician who ordered it.
• b) Nurse who administers it.
• c) Pharmacist who verifies and prepares it.
• d) Patient who receives it.

Answer: c) Pharmacist who verifies and prepares it.