CNSC Parenteral Nutrition Exam
Questions And Answers
/. 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?
1: Manganese
2: Copper
3: Zinc
4: Selenium - Answer-✅1: 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.
/.The adverse effects of lipid injectable emulsion (ILE) administration in adult PN
prescription is best prevented by
1: supplementing with L-carnitine.
2: avoiding infusion rates >0.05 grams/kg/hour.
3: using Alternative ILEs.
4: ILE free PN solutions. - Answer-✅3: 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.
/.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?
1: Thiamine
2: Thiamine, folic acid, Pyridoxine, vitamin C
3: D, A, E and thiamine
4: 10 ml of pediatric intravenous multivitamin - Answer-✅2: 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).
References:
2021 Parenteral Nutrition Multivitamin Product Shortage Considerations. Updated
January 18, 2021. Available at:
https://www.nutritioncare.org/Guidelines_and_Clinical_Resources/Product_Shortages/2
021_Parenteral_Nutrition_Multivitamin_Product_Shortage_Considerations/
/.A pregnant patient is admitted with hyperemesis gravidarum (HG). Which of the
following is a clinical indication for PN use?
1: Vomiting NOT controlled with supportive care within 48 hours
2: Intolerance to EN trial and supportive care measures
3: Patient refusal of EN tube placement
4: Fluid and electrolyte imbalances - Answer-✅2: 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.
, References:
Mogensen, Kris M.; and Erick, Miriam. "Pregnancy and Lactation." The ASPEN Adult
Nutrition Support Core Curriculum. 3rd ed. Silver Spring: American Society for
Parenteral and Enteral Nutrition, 2017. 397-417. Print.
/.Rapid intravenous infusion of potassium phosphate may result in
1: thrombophlebitis.
2: hypermagnesemia.
3: metabolic acidosis.
4: rhabdomyolysis. - Answer-✅1: 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.
References:
Canada, Todd W., Lord, Linda M. Fluids, Electrolytes, and Acid-Base Disorders. The
ASPEN Adult Nutrition Support Core Curriculum. 3rd ed. Silver Spring: American
Society for Parenteral and Enteral Nutrition, 2017. 113-137. Print.
/.What is the most common complication associated with parenteral nutrition (PN)
administration?
1: Hypophosphatemia
2: Hyperkalemia
3: Hyponatremia
4: Hyperglycemia - Answer-✅4: 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.
/.What is the glycemic target for the majority of critically ill adult patients?
Questions And Answers
/. 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?
1: Manganese
2: Copper
3: Zinc
4: Selenium - Answer-✅1: 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.
/.The adverse effects of lipid injectable emulsion (ILE) administration in adult PN
prescription is best prevented by
1: supplementing with L-carnitine.
2: avoiding infusion rates >0.05 grams/kg/hour.
3: using Alternative ILEs.
4: ILE free PN solutions. - Answer-✅3: 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.
/.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?
1: Thiamine
2: Thiamine, folic acid, Pyridoxine, vitamin C
3: D, A, E and thiamine
4: 10 ml of pediatric intravenous multivitamin - Answer-✅2: 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).
References:
2021 Parenteral Nutrition Multivitamin Product Shortage Considerations. Updated
January 18, 2021. Available at:
https://www.nutritioncare.org/Guidelines_and_Clinical_Resources/Product_Shortages/2
021_Parenteral_Nutrition_Multivitamin_Product_Shortage_Considerations/
/.A pregnant patient is admitted with hyperemesis gravidarum (HG). Which of the
following is a clinical indication for PN use?
1: Vomiting NOT controlled with supportive care within 48 hours
2: Intolerance to EN trial and supportive care measures
3: Patient refusal of EN tube placement
4: Fluid and electrolyte imbalances - Answer-✅2: 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.
, References:
Mogensen, Kris M.; and Erick, Miriam. "Pregnancy and Lactation." The ASPEN Adult
Nutrition Support Core Curriculum. 3rd ed. Silver Spring: American Society for
Parenteral and Enteral Nutrition, 2017. 397-417. Print.
/.Rapid intravenous infusion of potassium phosphate may result in
1: thrombophlebitis.
2: hypermagnesemia.
3: metabolic acidosis.
4: rhabdomyolysis. - Answer-✅1: 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.
References:
Canada, Todd W., Lord, Linda M. Fluids, Electrolytes, and Acid-Base Disorders. The
ASPEN Adult Nutrition Support Core Curriculum. 3rd ed. Silver Spring: American
Society for Parenteral and Enteral Nutrition, 2017. 113-137. Print.
/.What is the most common complication associated with parenteral nutrition (PN)
administration?
1: Hypophosphatemia
2: Hyperkalemia
3: Hyponatremia
4: Hyperglycemia - Answer-✅4: 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.
/.What is the glycemic target for the majority of critically ill adult patients?
