Answers to Self-Assessment Questions - ACCP

8. Answer: A
J.G. is receiving propofol at 11 mL/hour, which provides
1.1 kcal/mL through its vehicle (10% fat emulsion). This
amount of propofol will provide 290 kcal/day and 29 g of fat
per day. The amount of fat emulsion in J.G.’s PN formulation
must be reduced to avoid overfeeding. Decreasing the lipid
emulsion by 29 g/day (Answer A) will reduce the fat intake by
about the same amount of fat being provided by the propofol
drip; making Answer A the best answer. Decreasing lipid
emulsion by 53 g/day (Answer C) would decrease the lipid
delivery by an amount that exceeds that being provided by
the propofol drip, making Answer C is incorrect. Answer
B (increase lipid emulsion by 29 g/day) and Answer D
(increase lipid emulsion by 53 g/day) are incorrect because
the lipid content should be reduced to avoid overfeeding.
Once the propofol drip is discontinued, readjustment of the
PN formulation will be required.
1. Lowrey TS, Dunlap AW, Brown RO, Dickerson RN, Kudsk
KA. Pharmacologic influence on nutrition support therapy:
use of propofol in a patient receiving combined enteral and
parenteral nutrition support. Nutr Clin Pract 1996;11:147–9.
2. Mateu-de Antonio J, Barrachina F. Propofol infusion and
nutrition support. Am J Health Syst Pharm 1997;52:2515–6.
9. Answer: C
Thiamine (Answer C) should be supplemented in
J.G.’s PN formulation because it is lost in significant
amounts during CRRT, making Answer C the correct
answer. Thiamine is important in dextrose metabolism,
and supplementation of 50–100 mg/day is recommended
for patients receiving CRRT. Vitamin A (Answer A) and
vitamin D (Answer B) are fat-soluble and are not removed
to any appreciable degree during CRRT, so Answer A and
Answer B are incorrect. Although vitamin C (Answer D) is
lost in the CRRT filtrate, the clinical significance of this loss
is unknown, and vitamin C supplementation is not currently
recommended; thus Answer D is incorrect.
1. Berger MM, Shenkin A, Revelly JP, Roberts E, Cayeux MC,
Baines M, et al. Copper, selenium, zinc, and thiamine balances
during continuous venovenous hemodiafiltration in critically
ill patients. Am J Clin Nutr 2004;80:410–6.
2. Story DA, Ronco C, Bellomo R. Trace element and vitamin
concentrations and losses in critically ill patients treated
with continuous venovenous hemofiltration. Crit Care Med
1999;27:220–3.
10. Answer: D
In patients like J.G. (weight 60 kg) receiving CRRT,
protein intakes of 2.5 g/kg/day have been shown to
optimize nitrogen balance; thus Answer D (150 g/day) is
correct. Protein intakes less than 2.5 g/kg/day have been
associated with serum amino acid concentrations below the
reference range, whereas protein intakes of 2.5 g/kg/day
are associated with a normalization of serum amino acid
concentrations and a higher prevalence of positive nitrogen
balance. Answer A (60 g/day), Answer B (90 g/day), and
Answer C (120 g/day) provide only 1 g/kg/day, 1.5 g/kg/day,
and 2 g/kg/day of protein, respectively; therefore, Answer
A, Answer B, and Answer C are incorrect because the
protein intake is insufficient to meet J.G.’s needs.
1. Scheinkestel CD, Adams F, Mahony L, Bailey M, Davies
AR, Nyulasi I, et al. Impact of increasing parenteral protein
loads on amino acid levels and balance in critically ill anuric
patients on continuous renal replacement therapy. Nutrition
2003;19:733–40.
2. Scheinkestel CD, Kar L, Marshall K, Bailey M, Davies A,
Nyulasi I, et al. Prospective randomized trial to assess caloric
and protein needs of critically ill, anuric, ventilated patients
requiring continuous renal replacement therapy. Nutrition
2003;19:909–16.
11. Answer: C
In patients like J.G. with ARF, there are derangements
of serum amino acids. Studies have demonstrated that
patients with ARF should receive an essential–nonessential
amino acid combination when PN is required; thus, Answer
C (essential plus nonessential amino acid combination
formulation) is the correct option for J.G.’s PN formulation.
Essential amino acid–only formulations (Answer A) are
more costly than standard amino acid formulations and have
not been shown to produce a clinical benefit; thus Answer
A is incorrect. A nonessential amino acid formulation
(Answer B) would put J.G. at risk of amino acid deficiencies
if essential amino acids were not provided, so Answer B is
incorrect. Modular protein formulations (Answer D) are not
available for administration in PN formulations but are used
in enteral nutrition (EN) to supplement oral intake or tube
feeds; therefore, Answer D is incorrect.
1. A.S.P.E.N. Board of Directors and the Clinical Guidelines
Task Force. Guidelines for the use of parenteral and enteral
nutrition in adult and pediatric patients. JPEN J Parenter
Enteral Nutr 2002;26S:1SA–6SA.
2. Mirtallo JM, Schneider PJ, Mavko K, Ruberg RL, Fabri PJ.
A comparison of essential and general amino acid infusions
in the nutritional support of patients with compromised renal
function. JPEN J Parenter Enteral Nutr 1982;6:109–13.
3. Feinstein EI, Blumenkrantz MJ, Healy M, Koffler A, Silberman
H, Massry SG, et al. Clinical and metabolic responses to
parenteral nutrition in acute renal failure: a controlled doubleblind
study. Medicine 1981;60:124–37.
12. Answer: B
J.G. has ARF and is receiving CVVHD with citrate
anticoagulation. Her condition and therapies put her at risk of
both calcium and phosphorus imbalance. Close monitoring
of serum ionized calcium and phosphorus concentrations
is vital; therefore, Answer B (calcium balance should be
frequently assessed by monitoring J.G.’s serum ionized
calcium and serum phosphorus concentrations) is correct.
The serum ionized calcium is more reliable in patients with
hypoalbuminemia, which is common in ARF. Answer A
(citrate anticoagulation will likely induce hypercalcemia,
thus requiring a reduction in the amount of J.G.’s calcium
intake) is incorrect because citrate anticoagulation would
likely induce hypocalcemia because of calcium chelation by
citrate. Because calcium is filtered by CRRT, hypocalcemia
may develop, and the need for calcium supplementation is
common in patients receiving CRRT; therefore, Answer
C (hypocalcemia is rare in patients such as J.G. with ARF
receiving CRRT, and calcium supplementation will not
be required) is incorrect. Hyperphosphatemia is unlikely
because phosphorus is removed by CRRT; however, this
would not preclude correction of hypocalcemia, if necessary.
Therefore, Answer D (calcium supplementation in J.G.
Pharmacotherapy Self-Assessment Program, 6th Edition 37 Gastroenterology and Nutrition Answers