MCQ Quiz: TPN/Nutrition

Total Parenteral Nutrition (TPN) is a life-sustaining, complex therapy that places pharmacists in a critical decision-making role. From calculating a patient’s precise nutritional needs to ensuring the sterile compounding of a stable and compatible formulation, pharmacist expertise is essential for patient safety and efficacy. As detailed in the Patient Care, Sterile Compounding, and Professional Skills Lab curricula, managing TPN requires a deep understanding of clinical nutrition, fluid and electrolyte balance, and the metabolic complications that can arise. This quiz will test your knowledge on the key principles of parenteral nutrition, from order writing and compounding to monitoring for complications like refeeding syndrome.

1. Parenteral nutrition (PN) is indicated for a patient who:

• a) Can meet 100% of their nutritional needs with an oral diet.
• b) Has a non-functional or inaccessible gastrointestinal (GI) tract.
• c) Prefers not to eat by mouth.
• d) Needs short-term nutritional support for 1-2 days. Answer: b) Has a non-functional or inaccessible gastrointestinal (GI) tract.

2. What is the primary reason peripheral parenteral nutrition (PPN) is considered a short-term therapy?

• a) The osmolarity of PPN solutions must be limited (<900 mOsm/L) to prevent phlebitis, which restricts caloric delivery.
• b) PPN lines have a higher infection risk than central lines.
• c) PPN solutions are more expensive than central line solutions.
• d) PPN can only be used for a maximum of 24 hours. Answer: a) The osmolarity of PPN solutions must be limited (<900 mOsm/L) to prevent phlebitis, which restricts caloric delivery.

3. In a parenteral nutrition formulation, dextrose provides how many kilocalories per gram?

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

4. The protein component of a PN solution is provided as:

• a) Intravenous lipid emulsion
• b) Albumin
• c) Crystalline amino acid solutions
• d) Dextrose Answer: c) Crystalline amino acid solutions

5. To prevent calcium-phosphate precipitation during the compounding of a TPN, what is a key procedural step?

• a) Add calcium and phosphate to the bag at the same time.
• b) Add calcium early in the mixing process and phosphate last.
• c) Add phosphate early, agitate the bag, and add calcium near the end of the mixing sequence.
• d) Mix calcium and phosphate in a separate bag first. Answer: c) Add phosphate early, agitate the bag, and add calcium near the end of the mixing sequence.

6. Refeeding syndrome is a potentially fatal complication of nutritional repletion in severely malnourished patients. It is characterized by which hallmark electrolyte abnormality?

• a) Hypercalcemia
• b) Hypernatremia
• c) Hypophosphatemia
• d) Hyperchloremia Answer: c) Hypophosphatemia

7. Intravenous fat emulsions (IVFE) are a crucial component of TPN because they provide a concentrated source of calories and prevent:

• a) Hyperglycemia
• b) Essential fatty acid deficiency (EFAD)
• c) Dehydration
• d) Azotemia Answer: b) Essential fatty acid deficiency (EFAD)

8. A 3-in-1 or total nutrient admixture (TNA) is a TPN formulation that contains:

• a) Dextrose, amino acids, and electrolytes
• b) Dextrose, lipids, and vitamins
• c) Amino acids, lipids, and electrolytes
• d) Dextrose, amino acids, and intravenous fat emulsion in a single bag Answer: d) Dextrose, amino acids, and intravenous fat emulsion in a single bag

9. What is a key sign of an unstable 3-in-1 TPN admixture?

• a) A clear, transparent appearance
• b) The presence of a creamy layer or yellow-brown oil droplets, known as “cracking.”
• c) A slightly yellow color due to vitamins.
• d) The formation of gas bubbles. Answer: b) The presence of a creamy layer or yellow-brown oil droplets, known as “cracking.”

10. What is the standard caloric content of a 20% intravenous fat emulsion?

• a) 1.1 kcal/mL
• b) 2 kcal/mL
• c) 3.4 kcal/mL
• d) 4 kcal/mL Answer: b) 2 kcal/mL

11. Which of the following is a primary goal of providing nutritional support in a critically ill patient?

• a) To promote weight gain.
• b) To mitigate the metabolic stress response and preserve lean body mass.
• c) To cure the underlying critical illness.
• d) To increase the patient’s appetite. Answer: b) To mitigate the metabolic stress response and preserve lean body mass.

12. When calculating a patient’s protein needs for a TPN, the pharmacist uses the patient’s:

• a) Age
• b) Clinical condition and degree of metabolic stress
• c) Serum albumin level
• d) Height Answer: b) Clinical condition and degree of metabolic stress

13. A pharmacist is asked to assess a patient’s TPN. What is the most important initial step in the Patient Care Process?

• a) Immediately compounding the TPN.
• b) Collecting patient information, including weight, lab values, and clinical status.
• c) Counseling the patient on TPN administration.
• d) Discontinuing all other medications. Answer: b) Collecting patient information, including weight, lab values, and clinical status.

14. A central line-associated bloodstream infection (CLABSI) is a major risk for patients receiving TPN. This is an example of what type of complication?

• a) Metabolic
• b) Hepatic
• c) Infectious
• d) Mechanical Answer: c) Infectious

15. To avoid hyperglycemia, the initial dextrose infusion rate in a new TPN should not typically exceed:

• a) 1-2 mg/kg/min
• b) 4-5 mg/kg/min
• c) 7-8 mg/kg/min
• d) 10 mg/kg/min Answer: b) 4-5 mg/kg/min

16. Which laboratory parameter must be closely monitored in a patient receiving IVFE?

• a) Serum creatinine
• b) Hemoglobin A1c
• c) Triglyceride levels
• d) Serum sodium Answer: c) Triglyceride levels

17. Parenteral nutrition-associated liver disease (PNALD) can be a long-term complication of TPN. What is a strategy to reduce this risk?

• a) Providing all calories as dextrose.
• b) Avoiding overfeeding and cycling the TPN infusion.
• c) Using a higher percentage of protein.
• d) Withholding all lipids from the formulation. Answer: b) Avoiding overfeeding and cycling the TPN infusion.

18. As covered in the Sterile Compounding course, what size in-line filter is recommended for a 2-in-1 TPN admixture (dextrose and amino acids)?

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

19. For a 3-in-1 TNA containing lipids, what size in-line filter is required to allow the fat globules to pass through?

• a) 0.1 micron
• b) 0.22 micron
• c) 1.2 micron
• d) 5 micron Answer: c) 1.2 micron

20. The decision to initiate enteral nutrition (EN) over parenteral nutrition (PN) is based on the principle:

• a) “If the gut works, use it.”
• b) PN is always safer than EN.
• c) EN is more expensive than PN.
• d) PN has fewer metabolic complications. Answer: a) “If the gut works, use it.”

21. A patient on TPN has a serum potassium of 2.8 mEq/L. The pharmacist should recommend:

• a) Removing all potassium from the TPN.
• b) Increasing the amount of potassium chloride or potassium phosphate in the TPN.
• c) Continuing the current TPN without changes.
• d) Adding sodium bicarbonate to the TPN. Answer: b) Increasing the amount of potassium chloride or potassium phosphate in the TPN.

22. In a TPN order, protein content is prescribed in units of:

• a) g/kg/day
• b) mg/mL
• c) mEq/L
• d) kcal/hr Answer: a) g/kg/day

23. Which of the following is a primary role of the pharmacist in TPN management?

• a) Placing the central line catheter.
• b) Calculating the patient’s daily nutritional requirements.
• c) Performing a physical assessment of the patient’s abdomen.
• d) Administering the TPN solution to the patient. Answer: b) Calculating the patient’s daily nutritional requirements.

24. The stability of a TNA is highly sensitive to pH and cation concentration. The final pH of the admixture should ideally be maintained above:

• a) 3.5
• b) 5.0
• c) 7.0
• d) 9.0 Answer: b) 5.0

25. A standard adult multivitamin infusion (MVI) added to a TPN provides:

• a) Both fat-soluble and water-soluble vitamins.
• b) Only fat-soluble vitamins.
• c) Only water-soluble vitamins.
• d) Only Vitamin K. Answer: a) Both fat-soluble and water-soluble vitamins.

26. Why should TPN be tapered off slowly rather than stopped abruptly?

• a) To prevent rebound hypoglycemia from continued endogenous insulin secretion.
• b) To prevent refeeding syndrome.
• c) To avoid a hypertensive crisis.
• d) To conserve the remaining TPN solution. Answer: a) To prevent rebound hypoglycemia from continued endogenous insulin secretion.

27. A patient develops a fever and elevated white blood cell count while on TPN through a central line. What is the primary concern?

• a) Refeeding syndrome
• b) Hypertriglyceridemia
• c) A central line-associated bloodstream infection (CLABSI).
• d) An allergic reaction to the TPN bag. Answer: c) A central line-associated bloodstream infection (CLABSI).

28. Performing TPN calculations is a key skill emphasized in which Professional Skills Lab course?

• a) Professional Practice Skills Laboratory II
• b) Professional Practice Skills Laboratory IV
• c) Professional Practice Skills Laboratory VI
• d) Professional Practice Skills Laboratory I Answer: c) Professional Practice Skills Laboratory VI

29. The most common carbohydrate source used in parenteral nutrition in the United States is:

• a) Fructose
• b) Lactose
• c) Dextrose monohydrate
• d) Sucrose Answer: c) Dextrose monohydrate

30. Which of the following is an advantage of a 2-in-1 TPN system over a 3-in-1 TNA?

• a) It is easier to compound.
• b) The clear solution allows for visual inspection of precipitates.
• c) It has a lower risk of hyperglycemia.
• d) It provides more calories. Answer: b) The clear solution allows for visual inspection of precipitates.

31. In calculating a patient’s fluid requirements for TPN, a common method is to use:

• a) The patient’s age.
• b) A weight-based calculation (e.g., 30-40 mL/kg/day).
• c) The patient’s serum sodium level.
• d) The amount of fluid the patient desires to drink. Answer: b) A weight-based calculation (e.g., 30-40 mL/kg/day).

32. What is the nitrogen balance study used for in nutritional assessment?

• a) To measure a patient’s total body water.
• b) To assess the adequacy of protein provision.
• c) To check for liver dysfunction.
• d) To determine the patient’s blood type. Answer: b) To assess the adequacy of protein provision.

33. In the management of TPN, what does “cycling” the TPN refer to?

• a) Rotating the TPN access site.
• b) Infusing the TPN over a shorter period (e.g., 12-18 hours) rather than continuously over 24 hours.
• c) Changing the TPN formulation every other day.
• d) Alternating between TPN and enteral nutrition. Answer: b) Infusing the TPN over a shorter period (e.g., 12-18 hours) rather than continuously over 24 hours.

34. The primary reason to cycle TPN is to:

• a) Give the patient a break from the infusion.
• b) Reduce the risk of TPN-associated liver disease.
• c) Make the TPN infusion more complicated.
• d) Save nursing time. Answer: b) Reduce the risk of TPN-associated liver disease.

35. A pharmacist is reviewing a TPN order. This task is an example of which Entrustable Professional Activity (EPA)?

• a) Fulfilling a medication order.
• b) Answering medication related questions using scientific literature.
• c) Educating a patient on the appropriate use of a medication.
• d) Performing a technical, administrative, and supporting operation of a pharmacy practice site. Answer: a) Fulfilling a medication order.

36. A malnourished patient is started on TPN. On day 3, labs show Phosphate=1.2 mg/dL, Mg=1.1 mEq/L, and K=2.9 mEq/L. This is indicative of:

• a) A normal response to TPN.
• b) Refeeding syndrome.
• c) PNALD.
• d) A bloodstream infection. Answer: b) Refeeding syndrome.

37. Which of the following medications is most likely to be added to a TPN bag for compatibility reasons?

• a) Phenytoin
• b) Amphotericin B
• c) Regular insulin
• d) Piperacillin-tazobactam Answer: c) Regular insulin

38. The osmolarity of a PN solution is a critical parameter primarily when it is being administered via:

• a) A central venous catheter
• b) A peripheral vein
• c) A nasogastric tube
• d) An oral syringe Answer: b) A peripheral vein

39. A patient’s TPN is discontinued abruptly. The pharmacist should immediately be concerned about the risk of:

• a) Severe hypertension
• b) Hypoglycemia
• c) Hyperkalemia
• d) Dehydration Answer: b) Hypoglycemia

40. The caloric value of protein in PN calculations is:

• a) 3.4 kcal/gram
• b) 9 kcal/gram
• c) 7 kcal/gram
• d) 4 kcal/gram Answer: d) 4 kcal/gram

41. Which of the following is a key step in preventing refeeding syndrome?

• a) Starting TPN at the patient’s full goal rate on day 1.
• b) Repleting electrolytes, especially phosphate, before and during nutritional support initiation.
• c) Providing a high carbohydrate load immediately.
• d) Withholding thiamine supplementation. Answer: b) Repleting electrolytes, especially phosphate, before and during nutritional support initiation.

42. The “cracking” of a TNA is more likely to occur in a solution with a(n):

• a) High pH and high electrolyte concentration.
• b) Low pH and low electrolyte concentration.
• c) Neutral pH.
• d) Absence of lipids. Answer: b) Low pH and low electrolyte concentration.

43. A pharmacist is on rounds in the ICU. The team wants to start TPN. The pharmacist’s first action should be to:

• a) Write the TPN order immediately.
• b) Assess if the patient is a candidate for enteral nutrition first.
• c) Ask the nurse to start a peripheral line.
• d) Start compounding the TPN in the patient’s room. Answer: b) Assess if the patient is a candidate for enteral nutrition first.

44. What is a key difference between enteral nutrition (EN) and parenteral nutrition (PN)?

• a) EN is administered intravenously, while PN is administered via the GI tract.
• b) PN bypasses the GI tract entirely, while EN utilizes it.
• c) EN has a higher risk of bloodstream infections.
• d) PN is less expensive and easier to manage. Answer: b) PN bypasses the GI tract entirely, while EN utilizes it.

45. Which of the following patient populations has unique nutritional needs often addressed in specialty PN formulations?

• a) Neonates and infants
• b) Healthy young adults
• c) Patients with mild hypertension
• d) Patients with seasonal allergies Answer: a) Neonates and infants

46. A pharmacist notes that a TPN order has calcium gluconate and sodium phosphate in high concentrations. The pharmacist’s primary concern is:

• a) The cost of the ingredients.
• b) The risk of Ca/Phos precipitation.
• c) The solution being too dilute.
• d) The patient receiving too much fluid. Answer: b) The risk of Ca/Phos precipitation.

47. Understanding TPN order sets is a key objective of which skills lab?

• a) Professional Practice Skills Laboratory I
• b) Professional Practice Skills Laboratory III
• c) Professional Practice Skills Laboratory VI
• d) Professional Practice Skills Laboratory II Answer: c) Professional Practice Skills Laboratory VI

48. Why are trace elements included in a TPN for a patient on long-term therapy?

• a) To provide extra calories.
• b) To prevent deficiencies of essential minerals like zinc, copper, and selenium.
• c) To improve the stability of the lipid emulsion.
• d) To add color to the TPN bag. Answer: b) To prevent deficiencies of essential minerals like zinc, copper, and selenium.

49. A patient on TPN develops elevated liver function tests (LFTs). The pharmacist should recommend:

• a) Increasing the dextrose infusion rate.
• b) Investigating for PNALD and considering cycling the TPN or reducing calories.
• c) Adding more lipids to the TPN.
• d) Discontinuing all LFT monitoring. Answer: b) Investigating for PNALD and considering cycling the TPN or reducing calories.

50. The comprehensive management of TPN, from assessment to compounding and monitoring, demonstrates the pharmacist’s role as:

• a) A dispenser of medications only.
• b) An integral member of the interprofessional nutrition support team.
• c) A financial advisor.
• d) A surgical consultant. Answer: b) An integral member of the interprofessional nutrition support team.