Module III, V3 Fundamentals of Nutrition and Metabolism

Question 1

What effect does fiber have on gastro-intestinal transit time?

1: Dietary fiber results in delayed gastric emptying.
2: The effects of fiber in the upper GI tract do not differ from the effects of fiber in the colon.
3: Fiber in the distal ileum increases gastric emptying.
4: Consumption of insoluble fiber and the presence of fiber in the distal ileum results in decreased gastric emptying by intensifying inhibitory feedback from distal gut

Answer 1

1: Dietary fiber results in delayed gastric emptying.

Effects of fiber in the upper intestinal tract can differ from those in the colon primarily because of partial or complete fiber degradation and fermentation by colonic bacterial enzymes. Dietary fibers included in a liquid and solid meal with a purified source of pectin(soluble fiber) slows gastric emptying, as does consumption of a solid meal high in natural food fiber. Consumption of insoluble fiber and the presence of fiber in the distal ileum results in decreased gastric emptying.

References:
Carbohydrates in human nutrition. (FAO Food and Nutrition Paper - 66). Report of a Joint FAO/WHO Expert Consultation, Rome, 14-18 April 1997. Reprinted 1998
Wrick KL, Robertson JB, Van Soest PJ, Lewis BA, Rivers JM, Roe DA, Hackler LR. The influence of dietary fiber source on human intestinal transit and stool output. J Nutr. 1983 Aug;113(8):1464-79.

Question 2

The accumulation of which trace element is associated with Wilson’s disease?

1: Copper
2: Manganese
3: Selenium
4: Iron

Answer 2

1: Copper

Copper accumulation in the liver and other organs can occur in Wilson’s disease, which is characterized by a genetic mutation of copper metabolism. Normal copper homeostasis is maintained via biliary excretion. Toxicity can occur with impaired biliary excretion.

References:
Clark SF. Vitamins and Trace Elements. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 121-151.

Question 3

The acute phase response has what effect on serum iron and ferritin levels?

1: Increases serum iron levels and increases serum ferritin levels
2: Increases serum iron levels and decreases serum ferritin levels
3: Decreases serum iron levels and decreases serum ferritin levels
4: Decreases serum iron levels and increases serum ferritin levels

Answer 3

4: Decreases serum iron levels and increases serum ferritin levels

The acute phase response to injury and infection suppresses iron transport. Clinically, serum iron levels are depressed, while serum ferritin levels are increased. The sequestering of iron into a storage form following injury and infection is thought to have several protective measures for the host. It reduces the availability of iron for microorganism proliferation and also reduces free radical production and oxidative damage to membranes and DNA.

References:
Clark SF. Vitamins and Trace Elements. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 121-151.

Question 4

The majority of dietary folate is reabsorbed via which of the following mechanisms?

1: Oncotic pressure
2: Enterohepatic circulation
3: Plasma hydrostatic pressure
4: Passive diffusion

Answer 4

2: Enterohepatic circulation

Dietary folate is converted to monoglutamate by jejunal enzymes for entry into the intestinal cell. It undergoes further reduction before entry into the portal circulation for reabsorption via enterohepatic circulation. Zinc deficiency, chronic alcohol consumption, changes in jejunal luminal pH and impaired bile secretion may limit folate absorption. Oncotic pressure, passive diffusion, and plasma hydrostatic pressure govern the movement of fluid between the plasma and interstitial spaces.

References:
Clark SF. Vitamins and Trace Elements. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 121-151.

Question 5

Which of the following tests is not used to assess vitamin A status?

1: Plasma carotenoid level
2: Serum retinol concentration
3: Plasma transthyretin-retinol binding protein (TTR-RBP) concentration
4: Serum retinol binding protein (RBP) level

Answer 5

1: Plasma carotenoid level

Retinoid compounds and carotenoids are included in the vitamin A family. Serum retinol concentration is a test used for assessing vitamin A status as it correlates well with dietary intake of vitamin A. RBP is required for retinol transport from the liver to intended tissues.

References:
Clark SF. Vitamins and Trace Elements. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 121-151.

Question 6

Choline supplementation has been investigated as a treatment for which of the following disease states?

1: Myocardial infarction
2: Pancreatic insufficiency
3: Hepatic steatosis
4: Alcoholic encephalopathy

Answer 6

3: Hepatic steatosis

Choline is required for lipid transport and metabolism. Low plasma choline levels in long term PN patients have been associated with elevated liver aminotransferase concentrations. Investigations reported that steatosis resolved following choline supplementation. Currently PN admixtures do not contain choline. Further studies to evaluate choline supplementation to prevent and treat PN associated liver disease are needed.

References:
Kumpf, Vanessa J., and Jane Gervasio. “Complications of Parenteral Nutrition.” The A.S.P.E.N. Adult Nutrition Support Core Curriculum. 2nd ed. Silver Spring: American Society for Parenteral and Enteral Nutrition, 2012. 284-97.

Question 7

Which can decrease the accuracy of an indirect calorimetry (IC) study?

1: mechanical ventilation with FiO2 >= 60.
2: holding routine nursing care or activities during the study.
3: measurement made in a quiet, thermoneutral environment.
4: stable nutrient intake for the previous 12 hours.

Answer 7

1: mechanical ventilation with FiO2 >= 60.

IC is the calculation of energy expenditure by analysis of the gas exchanged via measurement of oxygen consumption and carbon dioxide production. The Haldane transformation implies that the inert gas nitrogen (N2) is constant in both inspired and expired gases. If FiO2 is ≥ 60%, the risk of error on the denominator increases. Accuracy of IC measurement is dependent of patient, environmental and equipment related factors. The fraction of inspired oxygen (FiO2) needs to remain constant during the measurement. Measurements should be made in a quiet, thermoneutral environment and routine care during the study should be avoided. The rate and composition of nutrients being infused on a continuous basis should be stable for at least 12 hours for an accurate study.

References:
Wooley, J, Frankenfield D. Energy. In: Gottschlich MM, ed. The A.S.P.E.N. Nutrition Support Core Curriculum: A Case-Based Approach – The Adult Patient. Silver Spring, MD: A.S.P.E.N.; 2012: 22-35.
Fraipont V, Preiser C. Energy Estimation and Measurement in Critically Ill Patients. Journal of Parenteral and Enteral Nutrition 2013; 37(6) 705–713

Question 8

Indirect calorimetry (IC) calculates

1: total energy expenditure.
2: nitrogen balance.
3: heat released from the subject.
4: resting energy expenditure (REE) and respiratory quotient (RQ).

Answer 8

4: resting energy expenditure (REE) and respiratory quotient (RQ).

IC calculates resting energy expenditure (REE) and respiratory quotient (RQ) by measuring whole body oxygen (V02) and carbon dioxide (VC02) gas exchange using the abbreviated Weir equation. IC does not measure total energy expenditure, nitrogen balance, or heat released from the subject. Total energy expenditure includes resting metabolic rate (RMR), energy required for the thermogenic effect of digestion, and energy expenditure associated with physical activity. Nitrogen balance is determined using urine urea. Heat released from the subject is measured by direct calorimetry, which requires the subject to remain inside of an enclosed chamber during the measurement.

References:
Wooley, J, Frankenfield D. Energy. In: Gottschlich MM, ed. The A.S.P.E.N. Nutrition Support Core Curriculum: A Case-Based Approach – The Adult Patient. Silver Spring, MD: A.S.P.E.N.; 2012: 22-35.
Fraipont V, Preiser C. Energy Estimation and Measurement in Critically Ill Patients. Journal of Parenteral and Enteral Nutrition 2013; 37(6) 705–713

Question 9

Potential metabolic causes for a respiratory quotient (RQ) greater than 1 include all of the following EXCEPT

1: overfeeding.
2: hypoventilation.
3: excess CO2 production.
4: provision of excess sodium bicarbonate.

Answer 9

2: hypoventilation.

Computation of the RQ (ratio of CO2 production to O2 consumption) gives information about the validity of the measurement and the metabolism of the different macronutrients. An RQ of 0.85 indicates mixed substrate utilization, or appropriate nutrient delivery. In general, an RQ < 0.82 suggests underfeeding, or lipid catabolism, indicating the need to increase caloric delivery. An RQ greater than 1.0, with excessive CO2 production may be due to overfeeding, lipogenesis, and increased respiratory demand. A decrease in the total caloric and carbohydrate delivery is an appropriate action when the RQ is greater than 1.0. Administration of excess buffering agents such as sodium bicarbonate can also elevate the RQ. Hypoventilation would tend to reduce RQ measurements.

References:
Wooley, J, Frankenfield D. Energy. In: Gottschlich MM, ed. The A.S.P.E.N. Nutrition Support Core Curriculum: A Case-Based Approach – The Adult Patient. Silver Spring, MD: A.S.P.E.N.; 2012: 22-35.

Question 10

The catabolic phase of the metabolic response to critical illness usually lasts

1: 1 day.
2: 3 days.
3: 5 days.
4: 7 days.

Answer 10

4: 7 days.

The metabolic response to critical illness has three phases: the stress phase, the catabolic phase, and the anabolic phase. The stress phase typically lasts 24 hours. The catabolic phase occurs after resuscitation and usually lasts for 7 to 10 days. It is dominated by fever, hypercatabolism, gluconeogenesis, and increased oxygen demands. Ongoing metabolic support with the provision of adequate protein and avoidance of overfeeding is the focus of nutrition support during this phase. The anabolic phase of the stress response occurs after the acute phase response has resolved and can last for months and the therapeutic goal changes with patient clinical status.

References:
Wooley, J, Frankenfield D. Energy. In: Gottschlich MM, ed. The A.S.P.E.N. Nutrition Support Core Curriculum: A Case-Based Approach – The Adult Patient. Silver Spring, MD: A.S.P.E.N.; 2012: 22-35.

Question 11

Which of the following are examples of monosaccharides?

1: Galactose, sucrose, and glucose
2: Maltose, fructose, and lactose
3: Glucose, fructose, and galactose
4: Lactose, maltose, and sucrose

Answer 11

3: Glucose, fructCarbohydrates can be classified as either simple or complex. Simple carbohydrates include monosaccharides (one sugar unit) and disaccharides (two sugar units). Glucose, fructose, and galactose are examples of monosaccharides. The monosaccharides are water soluble and have low molecular weight.

References:
Ling, Pei-Ra, and Karen C. McCowen. “Carbohydrates.” The A.S.P.E.N. Adult Nutrition Support Core Curriculum. 2nd ed. Silver Spring: American Society for Parenteral and Enteral Nutrition, 2012. 36-50.ose, and galactose

Question 12

Phosphofructokinase, a rate-limiting enzyme of glycolysis, is inhibited when ATP is abundant. Why is this inhibition important?

1: Facilitates gluconeogenesis to maintain euglycemia
2: Allows the cell to divert glucose to be stored as glycogen
3: Promotes catabolism
4: Enhances the Tricarboxylic Acid (TCA) Cycle

Answer 12

2: Allows the cell to divert glucose to be stored as glycogenPhosphofructokinase, a rate-limiting enzyme of glycolysis, is inhibited when ATP is plentiful. This step is necessary to prevent further breakdown of glucose and allows the cell to divert glucose to be stored as glycogen for later use. When ATP is limited, phosphofructokinase is activated.

References:
Ling, Pei-Ra, and Karen C. McCowen. “Carbohydrates.” The A.S.P.E.N. Adult Nutrition Support Core Curriculum. 2nd ed. Silver Spring: American Society for Parenteral and Enteral Nutrition, 2012. 36-50.

Question 13

In the body, glycogen is predominantly found in the

1: brain and liver.
2: skeletal muscle and kidneys.
3: small intestine and brain.
4: liver and skeletal muscle.

Answer 13

4: liver and skeletal muscle

Glycogen is the storage form of carbohydrate in the body. In general, only approximately 5% of ingested glucose is polymerized into glycogen, with the majority being oxidized. Glycogen is present in small amounts in most body tissues but is mainly found in the liver and skeletal muscle.

References:
Ling, Pei-Ra, and Karen C. McCowen. “Carbohydrates.” The A.S.P.E.N. Adult Nutrition Support Core Curriculum. 2nd ed. Silver Spring: American Society for Parenteral and Enteral Nutrition, 2012. 36-50..

Question 14

In response to illness and trauma, there is an increase in which of the following hormones?

1: Cortisol, epinephrine, growth hormone, and glucagon
2: Insulin, epinephrine, estrogen, and somatostatin
3: Glucagon, gastrin, insulin-like growth factor, and renin
4: Leptin, cortisol, growth hormone, and cholecystokinin

Answer 14

1: Cortisol, epinephrine, growth hormone, and glucagon

During periods of illness and trauma, there is increased production of the stress hormones, such as epinephrine and cortisol, accompanied by an elevation in growth hormone and glucagon. These counterregulatory hormones all work to oppose insulin action, resulting in increased glucose production by the liver (may exceed 500 g of glucose/day) and decreased utilization of glucose in peripheral tissues. These changes are also responsible for increased protein breakdown from muscle and enhanced fatty acid oxidation, viewed as a metabolic adaptation to provide fuels for heightened demands.

References:
Ling, Pei-Ra, and Karen C. McCowen. “Carbohydrates.” The A.S.P.E.N. Adult Nutrition Support Core Curriculum. 2nd ed. Silver Spring: American Society for Parenteral and Enteral Nutrition, 2012. 36-50.

Question 15

Which of the following tests does not reflect selenium status?

1: Plasma selenium level
2: Erythrocyte concentration
3: Plasma glutathione peroxidase
4: Methionine

Answer 15

4: Methionine

Measurement of plasma glutathione peroxidase is reflective of the functional or long-term status of selenium. Values <10.5 U/mL erythrocytes are indicative of a deficiency. Selenium status can also be assessed by determining the selenium level in whole blood, plasma, serum, or erythrocytes. Plasma or serum level is reflective of recent selenium intake and levels greater than 100mcg/L represent adequate selenium status in adult patients. Methionine is an essential amino acid.

References:
Clark SF. Vitamins and Trace Elements. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 121-151.
Hardy G, Hardy I, Manzanares W. Selenium Supplementation in the Critically ill. NCP 2012;27:21-33.

Question 16

Which of the following is a sign observed in PN patients with inadequate chromium intake?

1: Weight gain
2: Hypoglycemia
3: Hyperglycemia
4: Rhabdomyolysis

Answer 16

3: Hyperglycemia

Chromium potentiates the action of insulin and is important in glucose and lipid metabolism. Chromium deficiency impairs glucose metabolism which may result in hyperglycemia.

References:
Clark SF. Vitamins and Trace Elements. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 121-151.

Question 17

Which of the following is a common sign seen in a patient with vitamin D toxicity?

1: Hypocalcemia
2: Metabolic bone disease
3: Soft tissue calcification
4: Hypophosphatemia

Answer 17

3: Soft tissue calcification

Signs of vitamin D toxicity include nausea, vomiting, weakness, fatigue, diarrhea, headache, confusion and tremor. Soft tissue calcification may occur with long term toxicity. Hypocalcemia, osteomalacia, and osteoporosis are seen with vitamin D deficiency.

References:
Clark SF. Vitamins and Trace Elements. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 121-151.

Question 18

Presence of dietary fat in the distal ileum contributes to

1: increased gastric emptying
2: slowed intestinal transit
3: bacterial fermentation
4: production of short chain fatty acids

Answer 18

2: slowed intestinal transit

Presence of fat in the distal ileum produces an inhibitor feedback effect called the “ileal brake”, which slows gastric emptying and intestinal transit. Fiber is fermented by bacteria in the colon into short-chain fatty acids.

References:
Tarleton, Sherry, and John K. DiBaise. “Short Bowel Syndrome.” The A.S.P.E.N. Adult Nutrition Support Core Curriculum. 2nd ed. Silver Spring: American Society for Parenteral and Enteral Nutrition, 2012. 511-22.
Van Citters G and Lin H. Ileal brake: neuropeptidergic control of intestinal transit. Curr Gastroenterol Rep. 2006; 8: 367-373.

Question 19

Treatment for gastric phytobezoars includes all of the following EXCEPT

1: flushing with cola.
2: enzymatic therapy with cellulase.
3: meat tenderizer that contains papain.
4: surgical removal of the bezoar.

Answer 19

3: meat tenderizer that contains papain.

Phytobezoars may consist of indigestible plant material such as fiber, skins and seeds. Cellulase and cola have been effectively used to help break down the bezoar. Treatment with papain should be avoided because it breaks down normal tissue and is associated with peptic ulcer disease, esophagitis and gastritis. In cases that do not respond to treatment, surgery can be performed to remove the bezoar.

References:
Frantz, David, Craig Munroe, Carol Rees Parrish, Joseph Krenitsky, Kate Willcutts, and Amy Fortune. “Gastrointestinal Disease.” The A.S.P.E.N. Adult Nutrition Support Core Curriculum. 2nd ed. Silver Spring: American Society for Parenteral and Enteral Nutrition, 2012. 426-53.

Question 20

The best method to administer psyllium soluble fiber via feeding tube is to

1: mix with formula and infuse via a gravity feeding bag
2: mix with formula and infuse with feeding pump
3: mix with water and other medications and give by syringe followed by 15 mL water flush.
4: dilute in water and give by syringe followed by 15 mL water flush.

Answer 20

4: dilute in water and give by syringe followed by 15 mL water flush.

Psyllium has been successfully administered via feeding tubes by diluting 1 tsp with 80 mL water, inject by syringe and follow with 15 mL water flush. There may be an association between the intake of dietary fiber and decreased effectiveness of some medications; therefore, timing of fiber and medication administration should be spaced apart. Manipulation of the feeding bag system is a risk for microbial growth through touch contamination.

References:
Bankhead R, Boullata J, Brantley S, et al. Enteral Nutrition Practice Recommendations. JPEN J Parenter Enteral Nutr. 2009;33:122-167.

Question 21

Which of the following methods to determine energy expenditure incorporate body surface area?

1: Harris-Benedict Equation
2: Ireton-Jones Equation
3: Mifflin-St. Jeor Equation
4: Swinamer Equation

Answer 21

4: Swinamer Equation

The Swinamer Equation uses body surface area in addition to physiological variables to predict resting metabolic rate (RMR). This equation has been found to predict RMR in about 55% of patients.

References:
Wooley, J, Frankenfield D. Energy. In: Gottschlich MM, ed. The A.S.P.E.N. Nutrition Support Core Curriculum: A Case-Based Approach – The Adult Patient. Silver Spring, MD: A.S.P.E.N.; 2012: 22-35.

Question 22

Underfeeding is associated with

1: poor wound healing.
2: hepatic steatosis.
3: azotemia.
4: hypertriglyceridemia.

Answer 22

1: poor wound healing.

Poor wound healing, impaired organ function, and low transport protein levels in the absence of inflammation or infection are a few of the complications associated with underfeeding. Hepatic steatosis, azotemia, and hypertriglyceridemia are all associated with overfeeding.

References:
Wooley, J, Frankenfield D. Energy. In: Gottschlich MM, ed. The A.S.P.E.N. Nutrition Support Core Curriculum: A Case-Based Approach – The Adult Patient. Silver Spring, MD: A.S.P.E.N.; 2012: 22-35.

Question 23

Which of the following is a true statement regarding the effects of dietary fiber on the GI tract?

1: Faster transit time throughout
2: Wheat Bran will improve symptoms of abd pain and bloating in IBS
3: Improvement in constipation
4: Improvement of diarrhea in tubefed patients

Answer 23

4: Improvement of diarrhea in tubefed patients

The influence of dietary fiber on total oral to anal transit time seems to be dependent on the type and source of fiber. In general GI transit time in UGI tract is generally slower(especially with soluble fibers) resulting in delayed gastric emptying. Fiber in the lower GI tract tends to hasten GI transit due to increased stool weight due to fiber and increased water and by increased bacterial mass from fiber fermentation which all can lead to increased propulsion of softer stools. Wheat Bran(insoluble fiber) actually seems to increase symptoms of abdominal pain and bloating in IBS, where as Psyllium(soluble fiber) have been shown to reduce incidence of involuntary stool leakage. The use of fiber to treat constipation although theoretically sensible has not consistently been shown to improve bowel function. Addition of fiber to tubefeed in ill patients has shown less diarrhea and more firm stools however, note that studies in this area do not consistently show benefit. NOTE that there is controversy in this area in defining constipation and diarrhea and many factors may also effect GI motility besides fiber - stress, illness, exercise,hormones,infections etc.

References:
Ling, Pei-Ra, and Karen C. McCowen. “Carbohydrates.” The A.S.P.E.N. Adult Nutrition Support Core Curriculum. 2nd ed. Silver Spring: American Society for Parenteral and Enteral Nutrition, 2012. 36-50.
A Klosterbuer, ZF Roughead, Jslavin. Benefits of Dietary Fiber in Clinical Nutrition. Nutr in Clin Pract 2011; 26:625-635.
Position of the American Dietetic Assoc: Health Implications of Dietary Fiber J Am Diet Assoc 2008;108:1716-1731

Question 24

The recently FDA-approved intravenous fat emulsion (IVFE), known as Smoflipid, differs from soybean oil-based fat emulsion in that it

1: contains egg yolk phospholipid as an emulsifying agent.
2: may be infused via peripheral or central intravenous line.
3: also contains MCT oil, olive oil and fish oil.
4: provides essential fatty acids (EFAs).

Answer 24

3: also contains MCT oil, olive oil and fish oil.

All clinically available IVFEs contain egg yolk phospholipid as an emulsifying agent. In addition, all currently manufactured IVFEs may be safely infused via a central or peripheral intravenous line. In addition to being an energy source, all IVFEs serve to provide EFAs to prevent the development of EFAD. Smoflipid is a blend of 30% soybean oil, 30% MCT oil, 25% olive oil, and 15% fish oil. It’s composition serves to be less pro-inflammatory than traditional IVFEs given its higher content of omega-3 fatty acids. Smoflipid contains an omega-6:omega-3 fatty acid ratio of 2.5:1.

References:
Anez-Bustillos L, Dao DT, Baker MA, et al. Intravenous fat emulsion formulations for the adult and pediatric patient: understanding the differences. Nutr Clin Pract. 31(5): 596-609. October 2016.
Biesboer AN, Stoehr NA. A product review of alternative oil-based intravenous fat emulsions. Nutr Clin Pract. 31 (5): 610-618. October 2016.

Question 25

Albumin has a half-life of approximately

1: 3 days.
2: 8 days.
3: 12 days.
4: 20 days.

Answer 25

4: 20 days.

Serum albumin is a visceral (hepatic) protein and has a half-life of 14-20 days. The half-lives of retinol-binding protein, prealbumin, and transferrin are approximately 12 hours, 2-3 days, and 8-10 days, respectively.

References:
Jensen, Gordon L., Pao Ying Hsiao, and Dara Wheeler. “Nutirition Screening and Assesment.” The A.S.P.E.N. Adult Nutrition Support Core Curriculum. 2nd ed. Silver Spring: American Society for Parenteral and Enteral Nutrition, 2012. 155-69.

Question 26

Which of the following vitamins requires bile salts for emulsification and integration into the micelle for intestinal absorption?

1: A
2: B1
3: B12
4: C

Answer 26

1: A

Absorption of fat-soluble vitamins (A, D, E, and K) requires bile salts for emulsification and integration into the micelle for absorption into the enterocyte. Water-soluble vitamins do not require incorporation into the micelles for intestinal absorption.

References:
Clark SF. Vitamins and Trace Elements. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 121-151.

Question 27

A patient awaiting liver transplant has been taking a diuretic to control ascites and peripheral edema. Which of the following acid-base disorders is expected?

1: Metabolic acidosis
2: Metabolic alkalosis
3: Respiratory acidosis
4: Respiratory alkalosis

Answer 27

2: Metabolic alkalos

In this patient, metabolic alkalosis (saline-responsive) is a consequence of chronic diuretic therapy used to control ascites and peripheral edema. These agents cause a loss of bicarbonate-poor, chloride-rich extracellular fluid leading to contraction of extracellular fluid volume. Since the original bicarbonate mass is now dissolved in a smaller fluid volume, an increase in bicarbonate concentration occurs.

References:
Langley G, Tajchman S. Fluids, Electrolytes, and Acid-Base Disorders. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 98-120.s

Question 28

Which of the following is an example of a short chain fatty acid?

1: Lauric acid
2: Stearic acid
3: Oleic acid
4: Butyric acid

Answer 28

4: Butyric acid

Fatty acids are molecules with an acidic carboxyl group at one end followed by a long chain of hydrogenated hydrophobic carbon atoms. Each fatty acid is chemically characterized by the number of carbon atoms and double bonds present. The four general classifications of fatty acids with respect to the number of carbon atoms are short chain (2-4 carbons), medium chain (6-12 carbons), long chain (14-18 carbons), and very long chain (20 carbons or more). Butyric acid contains 4 carbon atoms and is classified as a short chain fatty acid. Lauric acid (12 carbon atoms) is a medium chain fatty acid. Stearic acid and oleic acid are long chain fatty acids containing 18 carbon atoms each.

References:
Hise M, Brown J. Lipids. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 63-82.

Question 29

The basic structure of a triglyceride consists of

1: a phospholipid backbone with 3 fatty acid molecules attached via ester linkage.
2: a fatty acid backbone with 3 glycerol molecules attached via ester linkage.
3: a cholesterol backbone with 3 fatty acid molecules attached via ester linkage.
4: a glycerol backbone with 3 fatty acid molecules attached via ester linkage.

Answer 29

4: a glycerol backbone with 3 fatty acid molecules attached via ester linkage.

The basic structure of a triglyceride consists of a hydroxylated 3-carbon backbone (glycerol). Attached in an ester linkage at the carbon-1, carbon-2, and carbon-3 positions of the glycerol structure are various fatty acids.

References:
Hise M, Brown J. Lipids. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 63-82.

Question 30

Which of the following is an example of a short chain fatty acid?

1: Lauric acid
2: Stearic acid
3: Oleic acid
4: Butyric acid

Answer 30

4: Butyric acid

Fatty acids are molecules with an acidic carboxyl group at one end followed by a long chain of hydrogenated hydrophobic carbon atoms. Each fatty acid is chemically characterized by the number of carbon atoms and double bonds present. The four general classifications of fatty acids with respect to the number of carbon atoms are short chain (2-4 carbons), medium chain (6-12 carbons), long chain (14-18 carbons), and very long chain (20 carbons or more). Butyric acid contains 4 carbon atoms and is classified as a short chain fatty acid. Lauric acid (12 carbon atoms) is a medium chain fatty acid. Stearic acid and oleic acid are long chain fatty acids containing 18 carbon atoms each.

References:
Hise M, Brown J. Lipids. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 63-82.

Question 31

Oxidation of fatty acids for adenosine triphosphate (ATP) production occurs in

1: cells that contain mitochondria.
2: the mitochondria of the adipocyte only.
3: the red blood cells only.
4: the blood stream.

Answer 31

1: cells that contain mitochondria.

Mitochrondria are organelles found in most eukaryotes whose primary function is to generate ATP via oxidative phosphorylation, the major source of cellular energy. Fatty acids are broken down by various tissues to produce energy. Fatty acids are transported into the mitochrondria membrane and through the beta-oxidation pathway the fatty acid is degraded and released as ATP. Fatty acid (and/or lipid) oxidation releases substantially more energy than does oxidation of carbohydrate. Adipocytes store energy as fat. Red blood cells do not contain mitochrondria in their cytoplasm and rely on the metabolic pathway of glycolysis for ATP for energy.

References:
Hise M, Brown J. Lipids. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 63-82.

Question 32

Linoleic acid and α-linolenic acid are referred to as essential fatty acids for humans because

1: they are the only fatty acids that can be used for adenosine triphosphate (ATP) production.
2: they cannot be synthesized by humans and must be obtained through diet.
3: they are the only fatty acids absolutely required to sustain life.
4: they require L-carnitine to enter the mitochondria.

Answer 32

2: they cannot be synthesized by humans and must be obtained through diet.

Linoleic and α-linolenic acid are called essential fatty acids because they cannot be synthesized naturally by humans and must be supplied, exogenously via the diet. If they are not supplied, a deficiency known as essential fatty acid deficiency (EFAD) can ensue resulting in metabolic complications. All fatty acids (essential, non-essential, saturated or unsaturated, long or short chain) can be oxidized to produce ATP. Because of their length (>10 carbons), linoleic acid and α-linolenic acid both require L-carnitine to enter the mitochondria.

References:
Hise M, Brown J. Lipids. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 63-82.

Question 33

A 50-year-old male weighs 80 kg. Calculate the estimated volume of his intravascular space.

1: 4 L
2: 8 L
3: 12 L
4: 16 L

Answer 33

1: 4 L

Water, the most abundant substance in the body, constitutes approximately 50% of body weight in females and 60% of body weight in males. Total body water (TBW) is a function not only of weight, age, and gender but also of the relative amount of body fat. TBW is distributed among three main compartments: intracellular, extracellular, and transcellular fluid compartments. Approximately two-thirds is contained in the intracellular fluid, and the remaining one-third is in the extracellular fluid. One-fourth of the extracellular fluid is the intravascular space and three-fourths is in the interstitial space. Calculations for this patient are: TBW: 48 L = (80 x 0.6); Extracellular fluid: 16 L = (1/3 x 48); Intravascular space: 4 L = (1/4 x 16).

References:
Langley G, Tajchman S. Fluids, Electrolytes, and Acid-Base Disorders. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 98-120.

Question 34

Sorbitol-induced hypokalemia is caused by

1: inadequate dietary intake.
2: increased renal potassium loss.
3: excess potassium loss in the stool.
4: transcellular shift of potassium from the extracellular fluid into cells.

Answer 34

3: excess potassium loss in the stool.

Hypokalemia is almost always the result of abnormal potassium losses via the urine or stool. Hypokalemia can also develop from a transcellular shift of potassium from the extracellular fluid into cells or inadequate dietary intake. Sorbitol induces hypokalemia by promoting excess potassium loss in the stool.

References:
Langley G, Tajchman S. Fluids, Electrolytes, and Acid-Base Disorders. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 98-120.

Question 35

Mild hypercalcemia, defined as a total serum calcium of 10.3-12.9 mg/dL, should initially be treated with

1: furosemide diuresis.
2: hydration.
3: hemodialysis.
4: bisphosphonates.

Answer 35

2: hydration.

Mild hypercalcemia usually responds to hydration and ambulation and requires no further intervention. Severe hypercalcemia is treated initially with saline hydration to correct volume depletion and furosemide after hydration to enhance renal calcium excretion. Hemodialysis may be necessary in life threatening situations or in patients with renal insufficiency. Bisphosphonates can assist with treatment of hypercalcemia of malignancy, but their delayed onset of action decreases the utility of these agents in the acute care setting.

References:
Langley G, Tajchman S. Fluids, Electrolytes, and Acid-Base Disorders. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 98-120.

Question 36

Absorption of large polypeptides, oligopeptides and free amino acids takes place in the

1: mouth.
2: small intestine.
3: stomach.
4: large intestine.

Answer 36

2: small intestine.

Minimal protein digestion takes place in the mouth or esophagus. Hydrochloric acid secreted by the parietal cells of the stomach denatures the protein and makes it more susceptible for enzymatic action. It converts the inactive pepsinogen to active pepsin. Pepsin in turn activates other pepsinogen molecules or hydrolyzes specific peptide bonds into end products of large polypeptides, oligo peptides and free amino acids. This mixture known as acid chyme passes into the duodenum where majority of protein digestion takes place.

References:
Anderson CE, Energy and metabolism. In: Schneider HA , Anderson CE, Coursin DB. Eds. Nutrition support of Medical Practice. 2nd ed. Philadelphia, PA; Harper and Row; 1983: 10-22. Matthews DE. Proteins and amino acids. In : SHILS me, Olson JA, Rose AC, eds. Modern Nutrition in Health and Disease. 10th ed. Baltimore, MD: Williams and Wilkins; 2006:23-61

Question 37

When determining nitrogen balance, urea accounts for what percentage of total urine nitrogen losses?

1: 50%
2: 60%
3: 70%
4: 80%

Answer 37

4: 80%

Determining nitrogen balance using urinary urea is an approximation based on certain assumptions such as urea accounting for about 80% of total urinary nitrogen losses. Urinary urea nitrogen concentration is affected by stress and increased urinary excretion of non-urea nitrogen. Nitrogen balance determined with total urinary nitrogen is consistently more reliable.

References:
Young L, Kearns L, Schoefel S, Clark N. Protein. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 83-97.

Question 38

Supplemental arginine is considered therapeutic for

1: fuel for rapidly dividing cells.
2: increasing lean body mass.
3: immune function and wound healing.
4: improving hepatic steatosis.

Answer 38

3: immune function and wound healing.

Some amino acids administered in higher amounts may have therapeutic effects. Arginine is a semi-essential amino acid that has demonstrated importance in immune function and wound healing. Supplementation with arginine will enhance wound healing. Few studies have focused on the chronic wound and arginine supplementation. Supplementation with arginine in the critically ill septic patient population remains controversial.

References:
Young L, Kearns L, Schoefel S, Clark N. Protein. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 83-97.

Question 39

Transformation of free long-chain fatty acids into acylcarnitines requires

1: choline.
2: arginine.
3: glutamine.
4: carnitine.

Answer 39

4: carnitine.

Carnitine is a trimethyl amino acid similar in structure to choline, which is required as a cofactor for transformation of free long-chain fatty acids into acylcarnitines and transport into the mitochondria. Although a primary deficiency of carnitine is rare, it has been documented in preterm infants and chronic renal failure.

References:
Young L, Kearns L, Schoefel S, Clark N. Protein. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 83-97.

Question 40

In which part of the body are essential amino acids oxidized?

1: Muscle
2: Liver
3: Kidney
4: Small intestine

Answer 40

2: Liver

The hepatocyte is the only site for oxidation of essential amino acids. About 57% of the amino acids extracted by the liver are used for protein synthesis and oxidation.

References:
Young L, Kearns L, Schoefel S, Clark N. Protein. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 83-97.

Question 41

Which of the following is a common effect of enteral fiber on the intestinal tract?

1: Faster transit throughout
2: Increased fecal bacteria concentrations
3: Improvement in constipation
4: Improvement in diarrhea

Answer 41

4: Improvement in diarrhea
The influence of dietary fiber on total or oral–anal transit time seems to depend on the type and source of dietary fiber. Both non-fiber and fructooligosaccharide (FOS) containing enteral formulas can decrease overall concentration of fecal bacteria as compared with a normal diet. At present there is no clear indication that existing constipation can be effectively resolved by increasing the intake of dietary fiber. Using soluble fiber suggests possible benefits in reducing diarrhea during enteral nutrition support.

References:
Ling, Pei-Ra, and Karen C. McCowen. “Carbohydrates.” The A.S.P.E.N. Adult Nutrition Support Core Curriculum. 2nd ed. Silver Spring: American Society for Parenteral and Enteral Nutrition, 2012. 36-50.
Cresci, Gail, Jennifer Lefton, and Dema Halasa Esper. “Enteral Formulations.” The A.S.P.E.N. Adult Nutrition Support Core Curriculum. 2nd ed. Silver Spring: American Society for Parenteral and Enteral Nutrition, 2012. 185-205.

Question 42

Which of the following is a possible complication of dietary fiber-containing enteral formulas?

1: Altered absorption of minerals
2: Bloating and flatulence
3: Increased effectiveness of some medications
4: Fluid retention

Answer 42

2: Bloating and flatulence
Symptoms of transient abdominal discomfort, such as bloating and flatulence, might occur with the introduction of a new or large amount of dietary fiber. There have been a few reports of associations between the intake of dietary fiber and decreased effectiveness of antidepressants and lipid-lowering agents. Complications such as formation of an esophageal or intestinal bezoar can be reduced by adequate fluid provision.

References:
Ling, Pei-Ra, and Karen C. McCowen. “Carbohydrates.” The A.S.P.E.N. Adult Nutrition Support Core Curriculum. 2nd ed. Silver Spring: American Society for Parenteral and Enteral Nutrition, 2012. 36-50.

Question 43

Dietary fiber may help to regulate normal defecation by

1: increasing stool weight and bulk.
2: inhibiting the growth of colonic bacteria.
3: reducing incidence of constipation.
4: removing water from the colon.

Answer 43

1: increasing stool weight and bulk.

Dietary fiber that is not degraded or fermented in the colon increases stool bulk and weight. Fermented fiber encourages colonic bacterial growth adding to fecal mass. Unfermented fiber in the colon creates a gel which holds water. This results in increased stool water content and softened stool consistency to ease evacuation. At present there is no clear indication that existing constipation can be effectively resolved by increasing the intake of dietary fiber.

References:
Ling, Pei-Ra, and Karen C. McCowen. “Carbohydrates.” The A.S.P.E.N. Adult Nutrition Support Core Curriculum. 2nd ed. Silver Spring: American Society for Parenteral and Enteral Nutrition, 2012. 36-50.

Question 44

Consumption of soluble fiber contributes to

1: lower levels of high density lipoprotein cholesterol.
2: lower levels of total and low density lipoprotein cholesterol.
3: lower risk of developing colon cancer.
4: increase in blood glucose concentrations.

Answer 44

2: lower levels of total and low density lipoprotein cholesterol.

Soluble dietary fiber lowers total cholesterol and LDL cholesterol without changing or lowering HDL cholesterol levels. There is currently no clear evidence to support that soluble fiber lowers the risk of developing colon cancer or reducing recurrence of adenomas. Soluble fiber has been shown to have a slight decrease on plasma glucose and hemoglobin A1c.

References:
Ling, Pei-Ra, and Karen C. McCowen. “Carbohydrates.” The A.S.P.E.N. Adult Nutrition Support Core Curriculum. 2nd ed. Silver Spring: American Society for Parenteral and Enteral Nutrition, 2012. 36-50.

Question 45

During extended periods of fasting (starvation), the main source of energy is from

1: protein catabolism.
2: gluconeogenesis.
3: glycolysis.
4: fatty acid oxidation.

Answer 45

4: fatty acid oxidation.

During starvation, glucose utilization is substantially reduced in most tissues and organs because of a reduced supply of glucose and decline in circulating insulin concentration. Higher glucagon concentrations promote fatty acid oxidation. Fat tissue becomes the main energy source for nearly all tissues. After 14 days of fasting, adipose tissue can provide more than 90% of daily energy requirements.

References:
Ling, Pei-Ra, and Karen C. McCowen. “Carbohydrates.” The A.S.P.E.N. Adult Nutrition Support Core Curriculum. 2nd ed. Silver Spring: American Society for Parenteral and Enteral Nutrition, 2012. 36-50.

Question 46

Glycogen stores can sustain normal activities in a healthy 70 kg man for approximately

1: 1 day.
2: 3 days.
3: 7 days.
4: 14 days.

Answer 46

1: 1 day.

In a healthy 70 kg male, the liver contains approximately 100 grams of glycogen, potentially providing 390 kcal. Skeletal muscle contains about 300-400 grams of glycogen, yielding less than 1560 kcal, suggesting that an adult stores only enough glycogen for about a day of normal activity. Because glycogen is stored with water, this is a somewhat inefficient storage method.

References:
Ling, Pei-Ra, and Karen C. McCowen. “Carbohydrates.” The A.S.P.E.N. Adult Nutrition Support Core Curriculum. 2nd ed. Silver Spring: American Society for Parenteral and Enteral Nutrition, 2012. 36-50.

Question 47

Glucose and galactose gain access to enterocytes via

1: glucose-dependent insulinotropic polypeptide (GIP).
2: glucokinase.
3: enterokinase.
4: sodium-glucose transporter 1 (SGLT-1)

Answer 47

4: sodium-glucose transporter 1 (SGLT-1)

Glucose and galactose are transported from the intestinal lumen into the enterocyte via the SGLT-1. The transport process requires energy provided by hydrolysis of ATP and is, therefore, called an active transport system. Two molecules of sodium are cotransported with one molecule of glucose or galactose.

References:
Ling, Pei-Ra, and Karen C. McCowen. “Carbohydrates.” The A.S.P.E.N. Adult Nutrition Support Core Curriculum. 2nd ed. Silver Spring: American Society for Parenteral and Enteral Nutrition, 2012. 36-50.

Question 48

Which water-soluble vitamins do not require NA+ co-transporters for absorption?

1: Vitamin C and Vitamin B6
2: Vitamin E and Vitamin D
3: Vitamin B12 and Folic acid
4: B1 and Choline

Answer 48

3: Vitamin B12 and Folic acid

Vitamin B12 requires intrinsic factor for absorption. Intrinsic factor binds to B12 and is taken up by receptors in the distal ileum. Folic acid is absorbed by a carrier-mediated process, primarily in the proximal part of the small intestine.

References:
Colaizzo-Anas T. Nutrient Intake, Digestion, Absorption, and Excretion. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 3-21

Question 49

oss of parietal cells after a gastrectomy may lead to a deficiency of

1: vitamin C.
2: vitamin B12.
3: vitamin E.
4: cholin

Answer 49

2: vitamin B12.

Vitamin B12 requires intrinsic factor for absorption. Intrinsic factor, a glycoprotein is secreted by the parietal cells of the stomach, which binds to cyanocobalamin (Vitamin B12) and is taken up by receptors in the distal ileum. Loss of parietal cells for any reason (gastrectomy, pernicious anemia, and chronic gastritis) or loss of distal ileum may lead to Vitamin B12 deficiency.

References:
Colaizzo-Anas T. Nutrient Intake, Digestion, Absorption, and Excretion. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 3-21

Question 50

The presence of which of the following facilitates the absorption of sodium in the lumen of the small intestine?

1: Glucose
2: Potassium
3: Vitamin D
4: Protein

Answer 50

1: Glucose

The presence of glucose facilitates sodium absorption. Glucose is co-transported with sodium in the small intestine enhancing both sodium and water uptake. Oral rehydration fluids used to treat diarrhea should contain both NaCl and glucose.

References:
Colaizzo-Anas T. Nutrient Intake, Digestion, Absorption, and Excretion. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 3-21

Question 51

Medium-chain triglycerides (MCTs) do not require the formation of micelles or bile salts for absorption because they are

1: fat-soluble.
2: 2-5 carbons in length.
3: water-soluble.
4: anti-inflammatory.

Answer 51

3: water-soluble.

MCTs are hydrolyzed and pass through the enterocytes directly into the portal circulation.

References:
Colaizzo-Anas T. Nutrient Intake, Digestion, Absorption, and Excretion. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 3-21

Question 52

Mucosal atrophy that accompanies bowel rest may result from an absence of

1: short chain fatty acids.
2: glutamine.
3: glucose.
4: L-cysteine

Answer 52

2: glutamine.

Mucosal atrophy occurs during periods of bowel rest, minimal PO intake, and stress. Glutamine is a principal metabolic fuel for intestinal cells. An absence of glutamine may directly contribute to mucosal atrophy. Atrophic changes during bowel rest have been decreased with glutamine-enriched parenteral nutrition.

References:
Colaizzo-Anas T. Nutrient Intake, Digestion, Absorption, and Excretion. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 3-21

Question 53

An enzyme deficiency commonly seen in African Americans and Native Americans is

1: lactase.
2: maltase.
3: amylase.
4: sucrase.

Answer 53

1: lactase.
70%-100% of African Americans, Native Americans, Asian, and Mediterranean descendents are deficient of lactase enzyme. Low lactose diets or supplemental oral lactase improves dietary tolerance.

References:
Colaizzo-Anas T. Nutrient Intake, Digestion, Absorption, and Excretion. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 3-21

Question 54

Symptoms of diarrhea, bloating, and flatulence after ingestion of sugar are caused by

1: hydrolysis of lactose into monosaccharides.
2: deficiency of brush border oligosaccharidases.
3: decreased osmotic pressure in the colon.
4: digestion of starches in the small intestine.

Answer 54

2: deficiency of brush border oligosaccharidases.

A deficiency in brush border oligosaccharidases allows osmotically active undigested oligosaccharides to cause a shift of water into the intestinal lumen. The resulting increased pressure exerted by luminal contents increases further when colonic bacteria act on remaining oligosaccharides, thus increasing the number of osmotically active particles. Formation of CO2 and H2 from disaccharides further increases flatulence and bloating.

References:
Colaizzo-Anas T. Nutrient Intake, Digestion, Absorption, and Excretion. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 3-21

Question 55

The majority of fat digestion occurs in the

1: ileum.
2: mouth.
3: colon.
4: duodenum.

Answer 55

4: duodenum.

Fat digestion begins in the mouth and stomach by lingual lipase and gastric lipase respectively, however the majority of fat digestion occurs in the duodenum by pancreatic lipase.

References:
Colaizzo-Anas T. Nutrient Intake, Digestion, Absorption, and Excretion. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 3-21

Question 56

All of the following hydrolyze fat in the small intestine EXCEPT

1: pancreatic lipase.
2: cholesterol ester hydrolase.
3: phospholipase.
4: bile acids.

Answer 56

4: bile acids.

Pancreatic lipase, cholesterol ester hydrolase, and phospholipase are all pancreatic enzymes involved in fat digestion. These enzymes hydrolyze triglycerides, phospholipids, cholesterol esters, and fat-soluble vitamins in the duodenum. The role of bile acids in fat digestion is to act as emulsifiers.

References:
Colaizzo-Anas T. Nutrient Intake, Digestion, Absorption, and Excretion. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring,
MD: A.S.P.E.N.; 2012: 3-21

Question 57

RNA and DNA are hydrolyzed to form mononucleotides during the digestion of

1: nucleic acids.
2: protein.
3: fats.
4: carbohydrate.

Answer 57

1: nucleic acids

Ribonuclease and deoxyribonuclease from the pancreas hydrolyze RNA and DNA to form mononucleotides during the digestion of nucleic acids. During the final digestive process, nucleosides are cleaved into purines and pyrimidines and then absorbed by active transport.

References:
Colaizzo-Anas T. Nutrient Intake, Digestion, Absorption, and Excretion. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 3-21

Question 58

Which of the following is a conditionally essential amino acid that is also a primary fuel source of enterocytes?

1: Tryptophan
2: Proline
3: Glutamine
4: Arginine

Answer 58

3: Glutamine

Glutamine is the most abundant amino acid in the body and a vital fuel for rapidly dividing cells, such as enterocytes, fibroblasts, reticuloendothelial cells and malignant cells. In some conditions, such as trauma, sepsis, and exercise, the body’s glutamine requirement exceeds the rate of synthesis leading to a decrease in plasma and intracellular glutamine. Decreased glutamine levels are associated with intestinal mucosa atrophy, impaired immune function, and decreased protein synthesis.

References:
Young L, Kearns L, Schoefel S, Clark N. Protein. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 83-97.

Question 59

A parenteral nutrition (PN) formulation contains 95 grams of protein. How many grams of nitrogen are in the PN formulation?

1: 15 grams
2: 75 grams
3: 95 grams
4: 105 grams

Answer 59

1: 15 grams

The average nitrogen content of protein was determined to be 16%. The total grams of protein divided by 6.25 will determine the nitrogen content of protein in a PN solution.

References:
Young L, Kearns L, Schoefel S, Clark N. Protein. In: Mueller CM, ed. The A.S.P.E.N. Adult Nutrition Support Core Curriculum, 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2012: 83-97.

Question 60

The initial protein requirements for a critically ill trauma patient weighing 70 kg are

1: 55-70 grams.
2: 70-105 grams.
3: 105-140 grams.
4: 140-175 grams.

Answer 60

3: 105-140 grams

Because of the increased protein loss that is associated with critical illness, protein needs are elevated. The current recommendation for stressed trauma patients is that 20-25% of total nutrient intake be provided as protein. This equates to roughly 1.5-2g/kg/day. Exceptions include a recent study, which suggested that intensive care unit patients receiving continuous renal replacement therapy should receive 2-2.5 g/kg/day.

References:
Collier, Bryan R., Jill R. Cherry-Bukowiec, and Mary E. Mills. “Trauma, Surgery, and Burns.” The A.S.P.E.N. Adult Nutrition Support Core Curriculum. 2nd ed. Silver Spring: American Society for Parenteral and Enteral Nutrition, 2012. 392-411.