Module 2A - Parenteral Nutrition (V.6)

Question 1

Which of the following central venous catheters is the LEAST favorable for PN infusion?
A. Peripherally Inserted Central Catheter (PICC)
B. Femoral Catheter
C. Subclavian Catheter
D. Internal Jugular Catheter

Answer 1

B. Femoral Catheter

The Institute for Healthcare Improvement (IHI) Central Line Bundle should be used for central vascular access devices. This bundle is a group of evidenced-based interventions for patients with intravascular central catheters that, when implemented together, result in better outcomes than when implemented individually. One of the key components is optimal catheter site selection, with avoidance of central venous access devices with high risk for infection, such as femoral catheters, when alternate access is available.

Question 2

A patient in the ICU is receiving concurrent infusions of lipid injectable emulsion (ILE) and propofol. These concurrent infusions could potentially cause
A. hyperglycemia.
B. hypertriglyceridemia.
C. azotemia.
D. hypernatremia.

Answer 2

B. hypertriglyceridemia.

Propofol, an anesthetic agent, is used in the intensive care area for sedation. The vehicle for administering this drug is 10% IV lipid emulsion. The concurrent administration of propofol and ILE in PN can result in higher than recommended doses of IV lipid emulsion and hypertriglyceridemia if appropriate adjustments are not made.

Question 3

What biochemical evidence indicates essential fatty acid deficiency (EFAD)?
A. A serum triglyceride level < 50 mg/dL
B. A lymphocyte absolute count < 1000/microliter
C. A serum cholesterol level < 100 mg/dL
D. A triene to tetraene ratio > 0.2

Answer 3

D. A triene to tetraene ratio > 0.2

Two polyunsaturated fatty acids (linoleic, alpha-linolenic) cannot be synthesized by the body and are considered essential. Thus, an exogenous source of fat must be provided. Biochemical evidence of EFAD is determined by a triene: tetraene ratio greater than 0.2 (Holman Index). It is composed of the circulating ratio of mead acid (trienoic acid) to arachidonic acid (tetranoic acid). As the content of arachidonic acid decreases in the tissues, the content of mead acid increases due to elongation and desaturation of oleic acid. EFAD can occur when <1-2% of the total energy consumed is derived from linoleic acid (LA) and α-linolenic acid (ALA). Changes to the Holman Index can occur within 7-10 days in adults with restricted EFA intake and EFAD in 1 to 3 weeks in adults receiving ILE-free PN. Biochemical evidence typically precedes clinical signs and symptoms of EFAD. To prevent EFAD, 2% to 4% of daily energy requirements should be derived from linoleic acid and about 0.25-0.5% of energy from alpha-linolenic acid. This requirement is achieved when 500 mL of 10% ILE, 250 mL of 20% ILE administered twice weekly, or 500 mL of a 20% ILE given once a week. A trial of topical skin application or oral ingestion of oils to alleviate biochemical deficiency of EFAD may be given to patients who are intolerant to ILEs.

Question 4

When initiating a PN regimen that contains regular insulin, how often should capillary blood glucose levels be monitored?
A. Every 6 hours
B. Every 8 hours
C. Every 12 hours
D. Every 24 hours

Answer 4

A. Every 6 hours

Capillary blood glucose levels should be monitored every 6 hours and supplemented with an appropriately dosed sliding scale insulin coverage given subcutaneously as needed to maintain glucose in goal range. Once glucose concentrations are stable, the frequency of measuring capillary blood glucose concentrations can often be decreased.

Question 5

Rapid intravenous infusion of potassium phosphate may result in
A. thrombophlebitis.
B. hypermagnesemia.
C. metabolic acidosis.
D. rhabdomyolysis.

Answer 5

A. thrombophlebitis.

The leading complication with peripheral intravenous infusion is thrombophlebitis (an inflammation at the cannulation vein) with hallmark signs of pain, erythema, tenderness or a palpable cord. The risk of thrombophlebitis increases by day 4. Infusion rates of phosphate should not exceed 7 mmol/hr because faster rates can cause thrombophlebitis and soft tissue calcium-phosphate deposition. When considering the diluent (dextrose vs saline), dextrose solutions may worsen the hypokalemia by stimulating insulin release that promotes intracellular shifts of K+. Hypokalemia is refractory to treatment unless the magnesium deficit is corrected. Metabolic acidosis presents as low pH, CO2 & HCl, high PO4 & K+, low Ca. Hypophosphatemia may cause neuromuscular adverse effects, such as rhabdomyolysis.

Question 6

Creaming of a total nutrient admixture (TNA) appears as
A. a translucent band at the surface of the emulsion separate from the remaining TNA dispersion.
B. yellow-brown oil droplets at or near the TNA surface.
C. a continuous layer of yellow-brown liquid at the surface of the TNA.
D. marbling or streaking of the oil throughout the TNA.

Answer 6

A. a translucent band at the surface of the emulsion separate from the remaining TNA dispersion.

Answers b, c, and d describe potential visual signs of the terminal state of emulsion destabilization, commonly known as cracking. In this stage, small lipid particles coalesce to form large droplets ranging in size from 5-50 or more microns. These oil droplets pose potential clinical danger. In contrast, the initial stage in emulsion breakdown is creaming which occurs almost immediately upon standing once ILE has been mixed with other chemical constituents. The presence of a cream layer is visible at the surface of the emulsion as a translucent band separate from the remaining TNA dispersion. Although the lipid particles in the cream layer are destabilized, their individual droplet identities are generally preserved. In general, light creaming is a common occurrence and not a significant determinant of infusion safety except in extreme cases.

Question 7

Which of the following is a indication for the use of parenteral nutrition (PN)?
A. High output fistula
B. Crohn’s disease
C. Pancreatitis
D. Hyperemesis gravidarum

Answer 7

A. High output fistula

PN is indicated for a non-functioning or inaccessible gastrointestinal tract. PN is indicated in patients with a high output fistula (>500 mL/day). PN is not routinely needed as nutrition support for Crohn’s disease. The preferred route of administration for nutrition intervention in patients with acute pancreatitis is EN. Only patients with severe hyperemesis gravidarum refractory to EN and pharmacotherapy would require PN.

Question 8

Branched-chain amino acid (BCAA) formulas would be most appropriate for
A. a patient with a recent diagnosis of hepatocellular cancer.
B. prevention of a first episode of hepatic encephalopathy in a patient who has undergone a transjugular intrahepatic portosystemic shunt (TIPS) procedure.
C. initial management of acute hepatic encephalopathy.
D. a cirrhotic patient with chronic encephalopathy who is intolerant of standard protein sources despite optimal pharmacotherapy.

Answer 8

D. a cirrhotic patient with chronic encephalopathy who is intolerant of standard protein sources despite optimal pharmacotherapy.

Use of branched-chain amino acid-enriched diets nutrition support formulas is only indicated in chronic encephalopathy for those who cannot tolerate at least 1gm/kg/day of standard protein despite optimal pharmacotherapy. The use of BCAA solutions is not fully supported by the literature in hepatic encephalopathy. Encephalopathy is usually not caused by altered protein in the diet. Protein consumption with the recommended range does not worsen hepatic encephalopathy and in fact leads to improved body composition. ASPEN recommends the use of standard formulations for critically ill patients with acute or chronic liver disease.

Question 9

In adult parenteral nutrition patients, intravenous lipid emulsion (ILE) use should be limited when serum triglyceride levels rise above
A. 400 mg/dL.
B. 300 mg/dL.
C. 200 mg/dL.
D. 100 mg/dL.

Answer 9

A. 400 mg/dL.

Serum triglycerides provide a reasonable estimate of body lipid clearance. Hypertriglyceridemia in adults has resulted in impaired pulmonary function, immune suppression and increased risk of pancreatitis. When serum triglyceride levels exceed 400 mg/dL, ILE infusion should be decreased to levels that prevent fatty acid deficiency.

Question 10

According to the ASPEN PN Safety Consensus Recommendations all of the following are considered to be mandatory for the PN order form EXCEPT
A. Full generic name for each ingredient (unless brand name can identify unique properties of specific dosage form)
B. Recommended laboratory monitoring
C. Infusion schedule (continuous or cyclic)
D. Electrolytes ordered as complete salt form rather than individual ion

Answer 10

B. Recommended laboratory monitoring

The addition of recommended laboratory monitoring to PN order forms is strongly recommended, but it is not required. A complete PN order shall contain the following: complete patient identifiers, birth date or age, allergies, height and dosing weight in metric units, diagnosis/diagnoses, indication(s) for PN, administration route/vascular access device (peripheral versus central), contact information for prescriber, date and time order submitted, administration date and time, volume and infusion rate, infusion schedule (continuous or cyclic), and type of formulation (TNA versus dextrose/amino acids with separate ILE). PN ingredients shall be ordered as follows: amounts per day (for adult patients) or amounts per kilogram per day (for pediatric and neonatal patients), electrolytes as complete salt form, full generic name for each ingredient, using The Joint Commission approved abbreviations and avoiding ISMP error prone abbreviations, symbols, and dose designations, dose for each macronutrient and electrolyte, dose for vitamins (including MVI and individual entities), dose for trace elements (including multi-components and/or individual entities), dose for each non-nutrient medication.

Question 11

When should PN be used in Crohn’s disease?
A. As a primary therapy to rest the bowel
B. Only after failure to tolerate EN
C. To prevent associated malnutrition
D. Preoperatively regardless of nutrition status

Answer 11

B. Only after failure to tolerate EN

Studies comparing PN to EN in patients with Crohn’s disease found no advantage of parenteral over enteral nutrition. Remission rates were similar and there was no evidence that bowel rest with PN had any advantage. Therefore, EN should be used in patients with Crohn’s disease requiring nutrition support therapy. PN should be reserved for Crohn’s patients who do not tolerate EN. Peri-operative specialized nutrition support is indicated in patients with inflammatory bowel disease who are severely malnourished and in whom surgery may be safely postponed.

Question 12

Failure to provide linoleic and alpha linolenic acids with PN will most likely result in
A. pancreatic insufficiency.
B. hyperglycemia.
C. metabolic bone disease.
D. essential fatty acid deficiency (EFAD).

Answer 12

D. essential fatty acid deficiency (EFAD).

Although rare in recent years, EFAD may still occur in the contemporary practice of nutrition support therapy. Failure to provide at least 2% to 4% of the total caloric intake as linoleic acid and 0.25% to 0.5% of total caloric intake as alpha linolenic acid may lead to a deficiency of these two fatty acids.

Question 13

When is it most appropriate to start PN infusion in a patient with a new central venous catheter inserted at the bedside without fluoroscopy?
A. Immediately
B. After auscultating for catheter tip placement
C. After chest X-ray confirms correct placement of catheter tip
D. After ensuring there were no complications with insertion

Answer 13

C. After chest X-ray confirms correct placement of catheter tip

A common complication of central venous catheters inserted at the bedside is catheter misplacement, including pneumothorax. The use of fluoroscopy during catheter insertion allows immediate repositioning of the catheter tip to its correct location in the superior vena cava. PN solutions can be started immediately if the catheter was inserted with the use of fluoroscopy. However, central catheters placed at bedside without fluoroscopy should be radiographically confirmed and documented in the medical record before initial use. Once it has been determined the catheter is in the correct position, PN may be initiated. Auscultation is not a method to determine central venous catheter tip placement.

Question 14

What is considered to be the most serious complication of significant hyperphosphatemia?
A. Osteoporosis and fractures
B. Soft tissue and vascular complications
C. Hypoventilation
D. Hypercalcemia

Answer 14

B. Soft tissue and vascular complications

The most serious complication of hyperphosphatemia is soft tissue and vascular calcifications. Calcification occurs when the serum calcium level multiplied by the serum phosphorus level exceeds 55 mg per deciliter. Additional consequences of hyperphosphatemia are secondary hyperparathyroidism, renal osteodystrophy, and hypocalcemia.

Question 15

A pregnant patient is admitted with hyperemesis gravidarum (HG). Which of the following is a clinical indication for PN use?
A. Vomiting NOT controlled with supportive care within 48 hours
B. Intolerance to EN trial and supportive care measures
C. Patient refusal of EN tube placement
D. Fluid and electrolyte imbalances

Answer 15

B. Intolerance to EN trial and supportive care measures

Hyperemesis gravidarum (HG) is a severe form of pregnancy-induced nausea and vomiting. Due to the likelihood that the patient’s nutritional intake has been poor for several weeks due to vomiting, EN or PN may be required. Early treatment options would include antiemetic use, and oral intake would temporarily be avoided. Initiation of an EN trial for HG would be appropriate if the patient is still unable to take oral feedings after 24-48 hours of supportive therapy, as listed above. If the EN trial fails due to exacerbated nausea, vomiting, diarrhea, significant gastric residuals, or tube displacement and is associated with clinically significant weight loss (greater than 5% of body weight), it is appropriate to begin PN.

Question 16

When compared to the Dietary Reference Intakes (DRIs) for water-soluble vitamins given orally, the DRIs for parenterally administered water-soluble vitamins are
A. one-third.
B. one-half.
C. equal.
D. higher.

Answer 16

D. higher.

Current water-soluble vitamin daily parenteral doses are 2 to 2.5 times greater than the Recommended Dietary Allowance (RDA) or Adequate Intake (AI) because of increased requirements due to malnutrition, baseline vitamin deficiencies, and increased urinary excretion of water-soluble vitamins when used intravenously.

Question 17

What risk is associated with the abrupt cessation of a parenteral nutrition solution?
A. Hypokalemia
B. Hypoglycemia
C. Hypervolemia
D. Hypomagnesemia

Answer 17

B. Hypoglycemia

Abrupt discontinuation of parenteral nutrition (PN) solutions has been associated with rebound hypoglycemia. Patients requiring large doses of insulin have a greater propensity for rebound hypoglycemia, but predetermining which patients will experience rebound hypoglycemia is difficult. Therefore, to reduce the risk of rebound hypoglycemia in susceptible patients, a 1- to 2-hour taper down of the infusion may be necessary. Checking capillary blood glucose level 30-60 minutes after PN cessation may help to identify rebound hypoglycemia.

Question 18

An adult critically ill patient with small bowel obstruction is started on PN. He will not receive any vitamins in PN due to parenteral multiple vitamins product shortage. Which of the following vitamins are recommended to be added individually to PN?
A. Thiamine
B. Thiamine, folic acid, Pyridoxine, vitamin C
C. D, A, E and thiamine
D. 10 ml of pediatric intravenous multivitamin

Answer 18

B. Thiamine, folic acid, Pyridoxine, vitamin C

ASPEN has recommended to not consider using pediatric intravenous multivitamins for adults. Additionally, pediatric intravenous multivitamins should not be used when there is a shortage. Try and supplement vitamins enterally if possible. Special considerations to water soluble vitamins - thiamin, B6, folic acid and vitamin C which may need to given individually on daily basis. Thiamin supplementation is indicated if patients receive carbohydrates and are at risk for thiamine deficiency (which can happen in patients on PN who do not receive vitamins for 3-4 weeks).

Question 19

In the adult critically ill obese patient, specific guidelines for the provision of calories and protein have been recommended by the Society of Critical Care Medicine and the American Society for Parenteral and Enteral Nutrition. For a patient with a BMI >30 kg/m2, which of the following choices best reflects the 2016 calorie recommendations for parenteral and enteral nutrition?
A. 11- 14 Kcal/kg ideal body weight/day
B. 11 - 14 Kcal/kg actual body weight/day
C. 22 - 25 Kcal/kg actual body weight/day
D. 22 - 25 Kcal/kg ideal body weight/day

Answer 19

B. 11 - 14 Kcal/kg actual body weight/day

For all classes of obesity where BMI is >30 kg/m2, the goal of the parenteral and enteral regimen should not exceed 65% to 70% of target energy requirements as measured by indirect calorimetry. If indirect calorimetry is not available, using the weight based equation 11–14 kcal/kg actual body weight/day for patients with BMI 30-50 kg/m2 and 22–25 kcal/kg ideal body weight/day for patients with BMI > 50 kg/m2 is recommended. The 2021 addendum to these 2016 guidelines did not provide specific additional caloric recommendations for obesity, however, the lower caloric targets recommended by these guidelines could indicate that aiming for the lower ends of the ranges listed in the 2016 guidelines for obese patients as outlined above might be prudent.

Question 20

According to the Centers for Disease Control and Prevention (CDC), which of the following is true regarding peripherally inserted central catheter (PICC) line care?
A. Scheduled replacement is recommended to prevent catheter-related blood stream infections (CRBSIs)
B. Remove the PICC line immediately if fever develops
C. Guidewire exchange should be used when the PICC is a suspected source of infection
D. Remove the PICC line only if it is suspected or known to be the source of infection

Answer 20

D. Remove the PICC line only if it is suspected or known to be the source of infection

Current CDC recommendations: Do not routinely replace central venous catheters, peripherally inserted central catheters, hemodialysis catheters, or pulmonary artery catheters to prevent catheter-related infections. Catheter replacement at scheduled time intervals has not shown a decrease in CRBSI. Do not remove CVCs or PICCs based on fever alone. Clinical judgment should be used to determine appropriateness of catheter removal if infection is evidenced from another site or a noninfectious cause is suspected. Catheter insertion over a guidewire is associated with less discomfort and a lower rate of mechanical complication when compared to percutaneous insertion at a new site, but replacement of temporary catheters during bacteremia should not be done over a guidewire due to source of infection (colonization of skin to insertion site).

Question 21

The routine use of preoperative parenteral nutrition (PN) is indicated for patients with a non-functioning GI tract who are
A. well-nourished.
B. mildly malnourished with secondary co-morbidities.
C. moderately-malnourished.
D. severely malnourished.

Answer 21

D. severely malnourished.

Many studies have identified the severely malnourished patient as benefiting from preoperative nutrition support with PN. Results from multiple preoperative PN studies of surgical patients have shown no overall reduction in perioperative mortality. However, significant reductions in perioperative complications are achieved in the severely malnourished patient receiving more than 7 days of preoperative PN. There have not been studies showing the same effect for well-nourished or moderately malnourished patient. There is currently no recommendation for use of mild as a degree of malnutrition.

Question 22

Which of the following factors has been associated with an increase in prescribing errors related to PN formulations?
A. Standardized PN order form
B. Calculation of PN dosages
C. PN components ordered as amount per day
D. PN components listed in same sequence on order form as PN label

Answer 22

B. Calculation of PN dosages

Common factors associated with the majority of PN prescribing errors include: inadequate knowledge regarding PN therapy, certain patient characteristics related to PN therapy (e.g., age, impaired renal function), miscalculation of PN dosages, specialized PN dosage formulation characteristics, and prescribing nomenclature.

Question 23

According to the ASPEN PN Safety Consensus Recommendations all of the following are considered to be mandatory for the inpatient PN label EXCEPT
A. infusion rate expressed in mL/hr.
B. beyond-use date and time.
C. size of in-line filter (1.2 or 0.22 micron).
D. electrolyte content expressed in individual ions.

Answer 23

D. electrolyte content expressed in individual ions.

Ingredients are to be expressed on the PN label in the same sequence and units of measure as the PN order. Electrolytes are to be ordered as complete salt forms as opposed to individual ions. The PN label should include the following: two patient identifiers, patient location or address, dosing weight in metric units, administration date and time, beyond use date and time, route of administration (central versus peripheral), prescribed volume and overfill volume, infusion rate in mL/h, duration of infusion (continuous versus cyclic), size of in-line filter (1.2 or 0.22 micron), completer name of all ingredients, barcode, all ingredients shall be listed in the same sequence and same units of measure as PN order, name of institution or pharmacy, and institution or pharmacy contact information (including telephone number). If ILE is to be infused separately, the ILE label should include: two patient identifiers, patient location or address, dosing weight, administration date and time, route of administration (central versus peripheral), prescribed about of ILE and volume required to deliver that amount, infusion rate in mL/hr, duration of infusion (not longer than 12 hours), complete name of ILE, beyond use date and time, name of institution or pharmacy, and institution or pharmacy telephone number.

Question 24

In the adult critically ill obese patient, specific guidelines for the provision of calories and protein have been recommended by the Society of Critical Care Medicine and the American Society for Parenteral and Enteral Nutrition. For a patient with a BMI > 30 kg/m2, which of the following choices best reflects those recommendations for the provision of protein in parenteral and enteral nutrition?
A. Less than 2 g/kg ideal body weight/day
B. Greater than or equal to 2 g/kg ideal body weight/day
C. Less than 2 g/kg actual body weight/day
D. Greater than or equal to 2 g/kg actual body weight/day

Answer 24

B. Greater than or equal to 2 g/kg ideal body weight/day

For all classes of obesity where BMI is >30 kg/m2, the goal of the parenteral and enteral regimen should not exceed 65% to 70% of target energy requirements as measured by indirect calorimetry. Protein should be provided in a range greater than or equal to 2 g/kg ideal body weight/day for patients with BMI 30–40 kg/m2, and up to 2.5 g/kg ideal body weight/day for patients with BMI ≥ 40 kg/m2 to preserve nitrogen balance. The 2021 addendeum to these guidelines did not provide additional recommendations for obese patients.

Question 25

The FDA currently recommends that daily intake of parenteral aluminum not exceed what amount?
A. 2 mcg/kg/day
B. 5 mcg/kg/day
C. 7 mcg/kg/day
D. 10 mcg/kg/day

Answer 25

B. 5 mcg/kg/day

Many PN products are contaminated with aluminum from the introduction of raw materials during the manufacturing process. Products of primary concern include calcium and phosphate salts, heparin and albumin. Variable levels have also been noted with some trace element, vitamin, and macronutrient products. The amount of contamination varies among manufacturers, lots, vial sizes and concentrations. The body has no effective barriers to aluminum contaminants given intravenously and must rely on renal excretion as the primary route of elimination to prevent toxicity. About 60% of infused aluminum is eliminated in patients with adequate renal function. The remainder is deposited in tissues, including the brain, bones, lung and liver. Alterations in bone formation and mineralization, parathyroid hormone secretion, and urinary calcium excretion have been attributed to aluminum toxicity. Those most vulnerable to aluminum toxicity include infants, children, those with renal insufficiency, and those on chronic PN. The FDA currently recommends that all manufacturers list the maximum aluminum concentration at product expiration, however inclusion of potential aluminum load on the compounded PN is not mandated. The upper limit of acceptable aluminum exposure is 5 mcg/kg/day per the 2004 FDA ruling.

Question 26

Cycling parenteral nutrition (PN) is recommended in patients
A. receiving short term parenteral nutrition.
B. at risk for liver dysfunction.
C. at risk for parenteral nutrition-associated hyperglycemia.
D. who are bed bound.

Answer 26

B. at risk for liver dysfunction.

Cycling of PN formulations should be considered for patients with or at risk for liver dysfunction, on long-term PN or those who are stable and active and may benefit from infusion free periods. Continuous PN infusion can result in hyperinsulinemia and hepatic fat deposition, thereby increasing risk for liver complications. Cycling PN infusion has been shown to reduce serum liver enzyme and conjugated bilirubin concentrations when compared to continuous PN infusion and may reduce the risk of parenteral nutrition-associated liver disease, especially in long-term PN-dependent patients.

Question 27

Your patient is receiving the following PN order. 2400 mL with 300 grams dextrose, 90 grams protein in addition to 225 mL 20% ILE. How many total calories and grams of fat is your patient receiving?
A. 1830 kcal, 40 grams fat
B. 2010 kcal, 40 grams fat
C. 1830 kcal, 45 grams fat
D. 1470 kcal, 45 grams fat

Answer 27

C. 1830 kcal, 45 grams fat

One (1) gram of dextrose is equal to 3.4 calories. Three hundred (300) grams provide 1,020 kcal. One (1) gram of protein is equal to 4 calories. Ninety (90) grams of protein provide 360 kcal. One (1) mL of 20% ILE is equal to 2 calories. ILE 20% provides 20 grams fat/100 mL; thus 225 mL provides 45 grams fat and 450 kcal.

Question 28

Which of the following best describes a lipid injectable emulsion (ILE) produced by the transesterification of fatty acids to form a composite triglyceride molecule?
A. Single oil
B. Multi-oil
C. Structured
D. Physical mixture

Answer 28

C. Structured

When two or more oils are mixed together, the emulsion product is called a physical mixture. Structured lipids are “designer” TG molecules that are specifically synthesized in the lab via enzymatic methodology via genetic engineering. The resulting TG mixture contains esterified MCTs and LCTs within the same TG molecule. Structured lipids rapidly deliver MCFAs which results in preferential absorption & rapid provisions of EPA/DHA. Other benefits include: better fatty acid absorption, lower infection rates, improved hepatic, renal and immune function.

Question 29

The adverse effects of lipid injectable emulsion (ILE) administration in adult PN prescription is best prevented by
A. supplementing with L-carnitine.
B. avoiding infusion rates >0.05 grams/kg/hour.
C. using Alternative ILEs.
D. ILE free PN solutions.

Answer 29

C. using Alternative ILEs.

Liver dysfunction results from a complex set of risk factors present in patients receiving PN, called PN associated liver disease (PNALD).

Recommended dosage for all types of ILE are 1-2g/kg/day, not to exceed 2.5g/kg/day. L-carnitine deficiency exacerbates lipid abnormalities but existing evidence has not confirmed that supplementation corrects hypertriglyceridemia. Alternative ILEs may preserve liver function and prevent hypertriglyceridemia due to their lower content of Soybean Oil/phytosterols. Phytosterols are structurally similar to cholesterol, and may interfere with bile synthesis and transport. This effect, in addition to high concentrations of peroxidation-sensitive PUFAs in plant-based ILE could lead to free radical damage of liver cells.

Lipid free PN Rx can cause EFAD within 2 weeks in acutely ill patients. Although physical evident of deficiency may not be noticed, biochemical deficiencies can be suspected by elevated AST, ALT and confirmed by triene: tetraene ratio.

Question 30

Which of the following is an indication for PN support in an adult cancer patient?
A. Abdominal tumor resulting in an unresolved small bowel obstruction for greater than seven days
B. Metastatic cancer, receiving palliative care
C. Receiving concurrent chemotherapy and radiation therapy
D. Mild malnutrition, scheduled for tumor resection surgery in three days

Answer 30

A. Abdominal tumor resulting in an unresolved small bowel obstruction for greater than seven days

Any adult patient with a gastrointestinal obstruction that precludes oral intake for at least one week may benefit from nutrition support. Moderately malnourished patients do not require PN unless oral intake is anticipated to be inadequate for more than one week. The palliative use of nutrition support in terminally ill cancer patients is rarely indicated. Most side effects of chemotherapy and radiation can be managed without the use of PN. Adult cancer patients scheduled for surgery who are severely malnourished may benefit from PN if the therapy can continue for 7-10 days preoperatively.

Question 31

When is parenteral nutrition (PN) indicated in severe burn patients?
A. Total body surface area burn exceeds 20%
B. As soon as possible after admission due to extremely high caloric needs
C. Enteral nutrition is contraindicated or unlikely to meet nutrition needs
D. Within 7-10 days if unable to meet greater than 60% enteral nutrition provisions

Answer 31

C. Enteral nutrition is contraindicated or unlikely to meet nutrition needs

Several studies have found that the use of PN in patients with burns has been associated with increased mortality. The use of PN in patients with burns is, therefore, reserved for patients who are unable to be fed enterally.

Question 32

Which of the following reduces the risk of calcium phosphate precipitation in PN?
A. Increased amino acid concentration
B. Use of calcium chloride as the calcium salt
C. Increased temperature
D. Adding calcium salt immediately after adding phosphate salt

Answer 32

A. Increased amino acid concentration

Increased concentration of amino acids reduce the risk of calcium phosphate precipitation by forming soluble complexes with calcium, thereby reducing the free calcium ions available to form insoluble dibasic calcium phosphate precipitates. Additionally, higher concentrations of amino acids may lower the pH of the PN formulation, which also improves calcium phosphate solubility. Calcium chloride dissociates more readily than calcium gluconate, increasing the free calcium ions available to bind with phosphate ions when using calcium chloride. Increasing temperature increases the dissociation of calcium salts. Storage under refrigeration reduces risk of calcium phosphate precipitation. When compounding PN, it is recommended to add the phosphate first and then add the calcium near the end of compounding to utilize the maximum volume of the PN formulation to dilute the salts. Adding the calcium and phosphate salts back-to-back causes locally high concentrations of these salts prior to adequate mixing.

Question 33

Which of the following complications is most likely to occur when transitioning a critically ill adult patient from parenteral to enteral nutrition?
A. Hypokalemia
B. Hyperkalemia
C. Hypoglycemia
D. Hyperglycemia

Answer 33

D. Hyperglycemia

When transitioning from parenteral to enteral nutrition, patients may receive nutrients in excess during overlap of therapy leading to hyperglycemia. Appropriate adjustments to limit total carbohydrate intake to no greater than 4 to 5 mg/kg/min can prevent this metabolic complication in many critically ill adult patients.

Question 34

What is the most common complication associated with parenteral nutrition (PN) administration?
A. Hypophosphatemia
B. Hyperkalemia
C. Hyponatremia
D. Hyperglycemia

Answer 34

D. Hyperglycemia

Hyperglycemia is the most common complication
associated with PN administration, even for those without diabetes, and can be caused by various factors. Stress-associated hyperglycemia in acutely ill and septic patients often develops as a result of insulin resistance, increased gluconeogenesis and glycogenolysis, and suppressed insulin secretion. Studies of hospitalized critically ill and noncritically ill patients receiving PN found that hyperglycemia was associated with increased risk for renal and cardiac dysfunction, infection, sepsis, pneumonia and death.

Question 35

In a patient with hepatobiliary disease, which of the following trace elements should be withheld or requires a dosage reduction when prescribing parenteral nutrition (PN)?
A. Selenium and manganese
B. Copper and selenium
C. Zinc and chromium
D. Copper and manganese

Answer 35

D. Copper and manganese

Excretion of copper and manganese is impaired in patients with hepatobiliary disease. Supplementation in parenteral nutrition can lead to excessive accumulation in the body and eventually toxicity. Hence reductions in manganese and copper dosing should be considered in patients with hepatobiliary disease. Manganese is a contaminant found within the PN solution components, thus patients will likely receive small doses of manganese even if eliminated from the PN trace element prescription. If copper and manganese are removed from PN, ongoing monitoring for their deficiency should be implemented.

Question 36

When compared to the Dietary Reference Intakes (DRIs) for fat- soluble vitamins given orally, the DRIs for parenterally administered fat-soluble vitamins are
A. lower.
B. equal.
C. two times higher.
D. four times higher.

Answer 36

B. equal.

The current recommended daily dose for parenteral fat-soluble vitamins is approximately the same as the oral Recommended Dietary Allowance (RDA) or Adequate Intake (AI). Though bioavailability of intravenous vitamins is much greater than those received orally, patients requiring parenteral nutrition are frequently found to have higher vitamin requirements. This is often due to these patients presenting with malnutrition, baseline vitamin deficiencies and metabolic changes secondary to acute and chronic illness. The provision of high parenteral vitamin doses has been in practice for over 30 years and no cases of toxicity have been reported.

Question 37

Which of the following is the most appropriate distal catheter tip placement of a peripherally inserted central catheter (PICC)?
A. Cephalic vein
B. Superior vena cava
C. Internal jugular vein
D. Supraclavicular vein

Answer 37

B. Superior vena cava

A peripherally inserted central catheter (PICC) is defined as a catheter inserted via peripheral vein whose distal tip lies in the superior vena cava. The cephalic or basilic veins are often used as the insertion site for PICCs. Central or peripheral access is not defined by the initial point of entry into the vascular system but rather by the position of the distal catheter tip. Central lines are defined as catheters with the distal tip in either the superior or inferior vena cava. Therefore, by definition, a PICC is used as central venous access.

Question 38

According to the ASPEN PN Safety Consensus Recommendations, which of the following is the best method to express the dextrose content on the label of a PN formulation for an adult in order to avoid misinterpretation?
A. Volume of the percent original concentration added (e.g., 500 mL of 50% dextrose)
B. Grams per liter (e.g., 250 g/L)
C. Percent of final concentration after admixture (e.g., 35% dextrose)
D. Grams per 24-hour nutrient infusion (e.g., 225 g/day)

Answer 38

D. Grams per 24-hour nutrient infusion (e.g., 225 g/day)

PN ingredients shall be ordered in amounts per day for adults and amounts per kilogram per day for pediatric and neonatal patients. This limits the confusion of conversion from amounts per liter, percent concentration, or volume. Amount per day refers to macronutrients in grams per day and micronutrients in mEq, mmol, mcg, or mg per day.

Question 39

A patient who weighs 75 kg is receiving 65 mL/hour of a 2-in-1 PN solution that contains 117 grams protein and 273 grams dextrose in addition to 250 mL of 20% ILE. What is the daily caloric content of this regimen per kg body weight?
A. 27.5 kcal/kg/day
B. 21.9 kcal/kg/day
C. 26.5 kcal/kg/day
D. 25.3 kcal/kg/day

Answer 39

D. 25.3 kcal/kg/day

One (1) gram of dextrose is equal to 3.4 calories. One (1) gram of protein is equal to 4 calories. One (1) mL of 20% ILE is equal to 2 calories. The total daily caloric intake equals 468 kcal (protein) + 928 kcal (dextrose) + 500 kcal (ILE) or 1896 kcal/day. When divided by the patient’s weight of 75 kg the total daily caloric intake per kg is 25.3 kcal/kg/day.

Question 40

According to the ASPEN PN Safety Consensus Recommendations, which of the following best describes safe PN compounding?
A. The preparation with automated compounding devices (ACDs) ensures an error-free process
B. All healthcare providers should have the ability to override soft and hard limit alerts from ACDs
C. Manual compounding of PN is appropriate when volumes of a PN component to be mixed are less than the ACD can accurately deliver
D. The preparation of compounded sterile preparations (CSPs) for all patient populations should be done at the same time

Answer 40

C. Manual compounding of PN is appropriate when volumes of a PN component to be mixed are less than the ACD can accurately deliver

Preparing PN with an ACD is not an error-free process, and error rates are reported to be 22% when automated and 37% when manually prepared. Compounding with ACDs should lead to improved compounding accuracy, enforcement of proper compounding sequence, and reduction in opportunities for human touch contamination. Institute for Safe Medication Practices (ISMP) recommends to install, test, and maximize automated dose-limit warnings in the pharmacy and ACD order entry systems with each organization developing weight based dosing limits applicable to their patient population. ASHP (American Society of Health-System Pharmacists) guidelines for the safe use of ACDs for the preparation of PN states that the pharmacy department should develop a monitoring and surveillance plan that promotes safe and efficacious use of the ACD at all times. This includes a review of dose limit alerts and overrides. When an ACD is used, it should deliver all PN ingredients. Manual PN compounding is appropriate when the volume of a PN component is less than the ACD can accurately deliver or if there is an interaction between a PN component and ACD component. Manual compounding is also appropriate when chemical interactions between PN components cannot be mitigated by sequencing the addition of the ingredients, or as a part of a conservation effort during drug shortages. Facilities that care for adult, pediatric, and neonatal populations should separate CSP preparation for each population and develop separation strategies to minimize error.

Question 41

Which parenteral amino acid (AA) formulation should be used in a hospitalized adult patient with acute kidney injury (AKI) requiring parenteral nutrition support?
A. Standard AA formulation
B. Branched-chain AA formulation
C. Essential AA formulation
D. Renal specialty AA formulation

Answer 41

A. Standard AA formulation

The ability to synthesize nonessential amino acids is reduced in patients with acute renal insufficiency. Enrichment of parenteral nutrition with branched chain amino acids has been studied, but there is insufficient evidence to recommend this approach. Renal amino acid formulations are composed primarily of essential amino acids and are relatively dilute. Studies have found no difference in mortality with a renal amino acid formulation. Therefore it is recommended to provide standard AA formulation for AKI patients.

Question 42

Which of the following PN formulas can be safely administered through a peripheral catheter?
A. 10% dextrose and 3% amino acid
B. 20% dextrose and 3% amino acid
C. 10% dextrose and 6% amino acid
D. 20% dextrose and 6% amino acid

Answer 42

A. 10% dextrose and 3% amino acid

ASPEN Clinical Guidelines suggest that PN with an osmolarity of up to 900 mOsm/L can be safely infused peripherally. Infusion of hypertonic parenteral solutions exceeding 900 mOsm/L through a peripheral catheter may result in phlebitis. Solutions with an osmolarity > 900 mOsm/L require central access. The lower concentrated dextrose solutions (5, 10%) and amino acid solutions (3%) are most often used for peripheral administration. The osmolarity of 10% dextrose= 500 mOsm/L. The osmolarity of 3% amino acid= 300 mOsm/L.

Question 43

Which of the following additives has the greatest risk of destabilizing the lipid injectable emulsion (ILE) in a total nutrient admixture (TNA)?
A. Sodium chloride
B. Calcium acetate
C. Iron dextran
D. Potassium phosphate

Answer 43

C. Iron dextran

Phase separation and the liberation of free oil from the destabilization of TNAs can result over time when an excess of cations is added to a given formulation. The higher the cation valence, the greater the destabilizing power; thus, trivalent cations such as Fe +3 (from iron dextran) are more disruptive than divalent cations such as calcium and magnesium. Monovalent cations such as sodium and potassium are least disruptive to the emulsifier, yet when given in sufficiently high concentrations, they may also produce instability. There is no safe concentration of iron dextran in any TNA.

Question 44

Which component of parenteral nutrition (PN) is most likely to impact anticoagulation in a patient receiving warfarin?
A. Standard amino acids and electrolytes
B. Dextrose and trace elements
C. Lipid injectable emulsion (ILE) and vitamins
D. Branched-chain amino acids and electrolytes

Answer 44

C. Lipid injectable emulsion (ILE) and vitamins

Parenteral multivitamin products are available with or without vitamin K. ILE are also a source of vitamin K, though the amount is variable. Patients receiving PN who are also on warfarin may require dosing adjustments to account for the additional vitamin K. The INR level should be closely monitored to ensure it is within therapeutic range.

Question 45

According to United States Pharmacopeia (USP) Chapter 797, a PN solution prepared from 8.5% amino acid solution with electrolytes and 70% dextrose, with multivitamins, trace elements, and famotidine added would be classified as
A. no risk.
B. low risk.
C. medium risk.
D. high risk.

Answer 45

C. medium risk.

The appropriate risk level, low, medium, or high, is assigned according to the corresponding probability of contaminating a compounded sterile preparation with (1) microbial contamination and (2) chemical and physical contamination. Low-risk compounding involves only transfer, measuring, and mixing manipulations with closed or sealed packaging systems that are performed promptly and attentively (i.e. reconstitution of a single-dose vial of lyophilized powder with sterile diluents for transfer into another container). Compounding of PN using manual or automated devices during which there are multiple injections, detachments, and attachments of nutrient source products to the device or machine to deliver all nutritional components to a final sterile container is classified as medium-risk (i.e. as in the question above). High-risk compounding differs from low- and medium risk compounding in that it involves using nonsterile ingredients or nonsterile devices prior to terminal sterilization (i.e. extemporaneously compounded L-glutamine for supplementation in a PN formulation).

Question 46

What is the glycemic target for the majority of critically ill adult patients?
A. 80 to 110 mg/dL
B. 220 to 240 mg/dL
C. 140 to 180 mg/dL
D. 180 to 220 mg/dL

Answer 46

C. 140 to 180 mg/dL

The current recommendation for glycemic target by the American Association of Clinical Endocrinologists (AACE) and the American Diabetes Association (ADA) is to maintain the glucose level between 140-180 mg/dL for the majority of critically ill adult patients. Lower glucose targets (110 mg/dL to 140 mg/dL) may be appropriate for some patients, but this is only appropriate when this can be safely achieved. Targets less than 110 mg/dL are not recommended due to the adverse effects of hypoglycemia.

Question 47

What is the preferred approach recommended by the American Association of Clinical Endocrinologists (AACE) and the American Diabetes Association (ADA) for subcutaneous insulin administration in the hospitalized adult patient with diabetes mellitus?
A. Sliding-scale insulin therapy
B. Basal insulin therapy
C. Bolus insulin therapy
D. Basal-bolus insulin therapy

Answer 47

D. Basal-bolus insulin therapy

The preferred approach for subcutaneous insulin administration is basal-bolus insulin therapy. This approach allows for basal insulin administered for hepatic glucose output combined with scheduled bolus insulin administered for meal times. There are three components to basal-bolus insulin therapy; basal insulin, nutritional component prior to meals and a correctional insulin.

Question 48

A patient on long-term parenteral nutrition begins to experience Parkinson-like symptoms. Which trace element toxicity is most likely to present with these symptoms?
A. Manganese
B. Copper
C. Zinc
D. Selenium

Answer 48

A. Manganese

Manganese is an essential trace element routinely added to long-term parenteral nutrition (PN) solutions. Though manganese deficiency is exceedingly rare, toxicity is well documented in these patients. Excess manganese accumulates in the brain leading to Parkinson disease-like symptoms such as tremor, involuntary movements and rigidity. Patients with abnormal liver function are at an increased risk for toxicity due to manganese being primarily excreted via bile. Manganese contamination of PN solutions can also occur during manufacturing and delivery of PN solutions. Despite this increased risk, there is limited evidence to support manganese-free PN solutions in patients without symptoms of toxicity or impaired liver function. Current recommendations for long-term PN patients are to serially monitor liver function as well as signs and symptoms of manganese toxicity.