Module 3A - Introduction to Enteral Nutrition (V.6)

Question 1

Which of the following strategies can be employed to reduce the risk of feeding tube occlusion?
A. Flush with water before and after medications
B. Increase total daily free water flushes
C. Switch enteral feeding to a fiber-containing enteral formula
D. Switch enteral feeding to a lower fat enteral formula

Answer 1

A. Flush with water before and after medications

Most common reasons for occlusion of feeding tubes are inadequate flushing, improper medication administration, and formula precipitates. Hydrolyzed or free amino acid formulas may be considered, however, they are more expensive, and are not the preferred intervention. Fiber-containing formulas may increase risk for physical drug interactions over fiber-free formulas. The fat or water content of the enteral formula does not seem to affect the risk of physical interaction with drugs, however high fat formulas may alter drug absorption through delayed gastric emptying.

Question 2

Which of the following describes an optimal method of preparing and administering medications via an enteral feeding tube?
A. Crush tablets and add them directly into the enteral formula
B. Administer liquid formulations undiluted to minimize fluid overload
C. Administer individual crushed medications in water
D. Add crushed tablets to liquid medications and administer the mixture all together

Answer 2

C. Administer individual crushed medications in water

The preferred method is to crush tablets and mix with water. Flushing the tube with water before and after each medication (including between each individual medication administered) helps to avoid physical interactions, both between medications and between medications and formula. Many liquid medications are hyperosmolar which can lead to diarrhea and/or may have high viscosity which can lead to tube clogging, so liquid dosage forms should be diluted with water prior to administration.

Question 3

What is the primary advantage of a direct percutaneous endoscopic placed jejunal tube (PEJ) versus a percutaneous endoscopic transgastric-placed jejunal tube (PEG-J)?
A. Reduced difficulty of placement
B. Reduced incidence of bleeding
C. Reduced incidence of migration
D. Reduced incidence of gastric outlet obstruction

Answer 3

C. Reduced incidence of migration

Placement of a direct PEJ has less potential for migration or flipping back into the stomach compared to the PEG-J method. Although gastric outlet obstruction may occur more in the PEG-J method by virtue of it crossing the pylorus, this is not the primary advantage of using direct PEJ. Bleeding risk is no different between methods. However, because of the difficulty in placement of direct PEJ, this technique may not be available in many institutions.

Question 4

In patients with pancreatitis, which of the following parameters would be LEAST important in predicting tolerance of enteral feedings?
A. APACHE II score
B. Duration of NPO
C. Abdominal pain
D. Triglyceride level

Answer 4

D. Triglyceride level

The most influential factor in determining tolerance of enteral nutrition in pancreatitis is disease severity as measured by APACHE II scores. Duration of NPO is also important as studies have shown poor tolerance in patients NPO for greater than or equal to 6 days prior to initiation of enteral feeding. Increasing abdominal pain is a clinical indication of enteral feeding intolerance in pancreatitis. Serum triglyceride levels are routinely used to measure tolerance of parenteral rather than enteral nutrition.

Question 5

In severe acute pancreatitis, when compared to parenteral nutrition, both gastric and jejunal feeds are associated with all of the following EXCEPT
A. decreased infection rates.
B. reduced length of hospital stay.
C. decreased pain.
D. reduced mortality rates.

Answer 5

C. decreased pain.

Both nasogastric feeds and jejunal feeds have been associated with a significant reduction in infectious morbidity, decreased hospital length of stay, reduced need for surgical intervention, reduced multiple organ failure, and decreased mortality. However, pain relapse is often noticed with nasogastric feeds when compared to parenteral nutrition.

Question 6

Which of the following enteral formulas is LEAST likely to be contaminated with micro-organisms?
A. Reconstituted powdered formula
B. Decanted liquid formula
C. Ready to hang formula
D. Blenderized tube feeding formula

Answer 6

C. Ready to hang formula

Enteral formulations are available as ready-to-feed liquids, ready-to-hang liquids, or powders that must be reconstituted. With ready-to-feed products, enteral formulations must be transferred from a can, bottle or brick pack to a refillable administration set or bag for delivery. The risk of microbial contamination increases as manipulation and handling of the formula and administration set increase. Open systems are limited to a hang time of 8-12 hours to decrease risk of contamination. Compared to liquid formulations, powdered formulas are more susceptible to contamination because they require more manipulation during preparation. Ready-to-hang (closed system) enteral formulations have less opportunity for contamination since no further manipulation of the formula should occur. Hang times for closed systems range from 24-48 hours.

Question 7

Which of the following would be the most appropriate tube feeding formula for a patient with extensive second and third degree burns?
A. High fat
B. High protein
C. High carbohydrate
D. High fiber

Answer 7

B. High protein

As part of the stress response, patients with burns exhibit increased breakdown of lean muscle tissue as a preferred source of energy. They also lose protein from open wounds. Therefore, patients with burns require increased intake of protein until significant wound healing is achieved.

Question 8

Which of the following medications has NOT been shown to lead to diarrhea in a patient receiving enteral nutrition?
A. Sorbitol-containing preparations
B. Alpha-2 adrenergic agonists
C. Antibiotics
D. Magnesium-containing preparations

Answer 8

B. Alpha-2 adrenergic agonists

Drugs may cause diarrhea due to hypertonicity, direct laxative action (e.g. sorbitol- or magnesium-containing preparations), or increased susceptibility to infectious enteritis (antibiotics). High osmolality of tube feeding, rapid bolus technique or significantly compromised albumin levels have also been cited. Alpha-2 adrenergic agonists, such as clonidine, have been shown to have significant antimotility effects and often prolong instead of reduce intestinal transit time.

Question 9

What is the maximum hang time for closed-system enteral formulas?
A. 24 hours
B. 36 hours
C. 48 hours
D. 72 hours

Answer 9

C. 48 hours

Research concludes that closed-system enteral formulas can hang for a maximum of 48 hours based on manufacturer guidelines.

Question 10

Which of the following is most often a CONTRAINDICATION to percutaneous endoscopic gastrostomy (PEG) tube placement?
A. Ascites
B. Partial gastrectomy
C. Obesity
D. Prior PEG

Answer 10

A. Ascites

Ascites is considered a relative contraindication to percutaneous endoscopic gastrostomy (PEG) placement because of the increased risk of complications such as peritonitis. Provided adequate transillumination is found during endoscopy, partial gastrectomy, prior PEG, and obesity are not contraindications to placement.

Question 11

Tube feeding is often held before and after enteral administration of all the following medications EXCEPT
A. warfarin.
B. metoprolol.
C. ciprofloxacin.
D. phenytoin.

Answer 11

B. metoprolol.

Metoprolol administration does not require any alteration in tube feeding schedules. The bioavailability of warfarin, phenytoin, carbamazepine, and fluoroquinolones, such as ciprofloxacin, may be altered with enteral nutrition and the enteral feeding is often held for up to two hours before and after administration to reduce interactions. When enteral feedings are held, the feeding schedules will need to be adjusted to achieve target nutrition goals. Many practitioners will justify continuing enteral nutrition around medications that could potentially interact and for adjustment of medication to help maintain therapeutic serum drug levels.

Question 12

An ICU patient requires vasopressor support to maintain hemodynamic stability. The patient’s mean arterial blood pressure is 50 mm Hg, vasopressor administration is decreasing and enteral nutrition (EN) is soon to be initiated. Which of the following is considered a possible early indicator of gut ischemia in this patient?
A. Decreased vasopressor support
B. Hypoactive bowel sounds
C. Increased passage of stool and flatus
D. Increased metabolic alkalosis

Answer 12

B. Hypoactive bowel sounds

According to current evidence, EN in critically ill patients with hemodynamic instability is still a clinical controversy. Feeding a patient before hemodynamic stability has been achieved may increase the risk of intestinal ischemia. Blood perfusion of the gut may be compromised in a patient who is still requiring high doses of vasopressor medications to maintain blood pressure. Even though EN may be provided with caution to patients on chronic, stable low doses of vasopressors, EN should be withheld in patients who are hypotensive (mean arterial blood pressure <50 mm Hg), have increasing vasopressor needs or who are hemodynamically unstable. For patients on vasopressors and EN, any signs of intolerance (abdominal distention, increasing nasogastric [NG] tube output or gastric residual volumes, decreased passage of stool and flatus, hypoactive bowel sounds, increasing metabolic acidosis) should be closely monitored as possible early signs of gut ischemia, and EN should be held until symptoms and interventions stabilize.

Question 13

Which of the following interventions may assist with the appropriate placement of a nasogastric feeding tube in an alert patient?
A. Administer IV metoclopramide
B. Keep patient NPO during insertion
C. Have the patient flex his head slightly forward
D. Place the patient supine for tube insertion

Answer 13

C. Have the patient flex his head slightly forward

Elevating the head of the bed to a sitting position, having the patient flex his head slightly forward once the tube tip is in the posterior nostril, and asking the patient to swallow small sips of water are all interventions utilized to prevent respiratory misplacement. Proper patient positioning during insertion narrows the airway passage to facilitate esophageal placement. Having the patient swallow during insertion decreases the risk of placing tube into the larynx. IV metoclopramide is a prokinetic agent that may assist with transpyloric tube passage.

Question 14

Use of a semi-elemental or elemental formula in place of a polymeric formula should be considered in all patients with
A. initiation of enteral nutrition.
B. intolerance to polymeric formula.
C. intestinal failure.
D. pancreatitis.

Answer 14

B. intolerance to polymeric formula.

Semi-elemental and elemental formulas are those with partially or completely hydrolyzed macronutrient content intended for patients with GI disorders or dysfunction. This may include patients with known malabsorptive disorders or those who exhibit signs and symptoms of intolerance to polymeric formulations. The use of peptide-based formula has not been extensively evaluated, and the results of the available studies have been contradictory. Two studies found that diarrhea was reduced by using a peptide-based formula, while other studies found that diarrhea increased or stayed the same following change to a peptide-based formula. The European Society for Clinical Nutrition and Metabolism (ESPEN) does not recommend the routine use of elemental formulas in Crohn’s disease, ulcerative colitis or short bowel syndrome. Clinicians should thoroughly investigate for other potential etiologies of a patient’s diarrhea or malabsorption rather than assume the enteral formula is the cause. Other potential causes of diarrhea include medications, rapid infusion of formula or fluid into the small intestine, and small intestinal bacterial overgrowth.

Question 15

A 60-year old female is admitted with a stroke and fails a swallowing evaluation. A nasogastric tube is placed, and the physician requests an isotonic formula. Which of the following calorie densities of enteral formulas is isotonic?
A. 1.0 kcal/mL
B. 1.2 kcal/mL
C. 1.5 kcal/mL
D. 2.0 kcal/mL

Answer 15

A. 1.0 kcal/mL

The osmolality of gastrointestinal secretions is approximately 300 mOsm/kg. A formula that is isotonic would have a similar osmolality to gastrointestinal secretions. The following are enteral formula caloric densities with typical osmolality: 1.0 kcal/mL (300-350 mOsm/kg), 1.2 kcal/mL (400-450 mOsm/kg), 1.5 kcal/mL (500-650 mOsm/kg), 2 kcal/mL (700-800 mOsm/kg).

Question 16

Which of the following represents modular products?
A. Safflower oil, protein, glucose, and selenium
B. Glucose, glutamine, water, and MCT oil
C. Protein, cholecalciferol, fiber, and safflower oil
D. MCT oil, glucose, fiber, and protein

Answer 16

D. MCT oil, glucose, fiber, and protein

Modular products are commonly used to fortify enteral nutrition regimens or meals served. Modular products are typically single-nutrient products and are available for use in addition to the selected oral or enteral regimens. They increase the protein, calorie, or fiber content of the feeding regimen. Vitamins, minerals, and water are required nutrients but are not considered modular products. The products can be mixed with water according to package directions for administration via the feeding tube or they may be mixed with supplements or foods on meal trays. They should not be added directly to the enteral nutrition formula.

Question 17

Compared to gastric feeding, post pyloric feeding is associated with which of the following outcomes in critically ill patients?
A. Longer time to achieve target nutrition
B. Increased nutrient delivery
C. Increased gastroesophageal regurgitation
D. Decreased rate of ventilator-associated pneumonia

Answer 17

B. Increased nutrient delivery

Based on a systematic review of studies comparing gastric and post pyloric feeding methods, post pyloric feeding is associated with reduced gastric residual volume and reflux, but adequately powered trials are not available to support prevention of aspiration pneumonia. Several studies document increased protein and energy delivery and a shorter time to target rate with small bowel feeding.

Question 18

The use of enteral nutrition formulas enriched with branched-chain amino acids may benefit patients with
A. cirrhosis.
B. hepatic failure.
C. liver transplantation.
D. refractory encephalopathy.

Answer 18

D. refractory encephalopathy.

The branched-chain amino acids (BCAAs) leucine, isoleucine and valine have been promoted for use in hepatic encephalopathy because they clear ammonia in the skeletal muscles, decreasing cerebral ammonia levels and reducing the uptake of aromatic amino acids (AAAs) across the blood-brain barrier. Due to impaired hepatic deamination, patients with liver failure may have alterations in amino acid levels, namely higher levels of AAAs (tyrosine, tryptophan, and phenylalanine) compared to BCAAs. This altered ratio of AAAs to BCAAs allows more AAAs to enter the brain and contribute to production of false neurotransmitters, which contribute to symptoms seen in hepatic encephalopathy. However, there is no evidence that use of high-BCAA formulations alters patient outcomes compared to provision of a standard enteral formula. Therefore, the use of these formulas should be limited to patients with encephalopathy that is unresponsive to standard medical therapy.

Question 19

Which of the following is LEAST likely to facilitate transpyloric placement of a nasoenteric feeding tube?
A. Endoscopic placement
B. Bedside electromagnetic imaging system
C. Fluoroscopic Placement
D. Weighted tube tips

Answer 19

D. Weighted tube tips

Both fluoroscopic and endoscopic placements have the highest percentage of successful transpyloric passage. A recent meta-analysis compared the performance of bedside electromagnetic-guided versus endoscopic placement. Procedure success rate was reported in all included studies. Pooled rate for electromagnetic-guided and endoscopically placed tubes was 82.6% and 83.1%, respectively. The success rate of radiological placement varies from 40% to 94%, depending on the local expertise. Weighed tips wouldn’t facilitate placement but might help reduce chance of post-pyloric tubes curling back into the stomach.

Question 20

A patient is receiving enteral nutrition during her second trimester of pregnancy. Nutritional assessment data reflect an average maternal weight gain of 0.42 lbs per week, normal fetal growth, an albumin of 2.0 gm/dL, and a nitrogen balance of +2 gm/day. Based on the data provided, which of the following parameters is not useful in assessing the efficacy of enteral nutrition in pregnancy?
A. Maternal weight gain
B. Fetal growth
C. Serum albumin
D. Nitrogen balance

Answer 20

C. Serum albumin

Maternal weight gain and fetal growth are the most important factors in assessing the adequacy and efficacy of enteral tube feedings in pregnancy. There is a strong correlation between infant birth weight and maternal weight. Positive nitrogen balance is important in assessing provision of adequate protein. In pregnancy, albumin levels can decrease as a result of changes in volume status as well as shift in production of gamma-globulin to alpha and beta-globulins. Use of serum albumin is not recommended to assess nutritional status.

Question 21

Which of the following is a benefit of early enteral nutrition in critically ill adult patients?
A. Increases translocation of gut bacteria
B. decreases structural integrity of intestinal villae
C. Maintains risk for infectious complications
D. Preserves gut mucosal integrity

Answer 21

D. Preserves gut mucosal integrity

Early appropriate enteral tube feeding may prevent the occurrence of bacterial translocation (the passage of bacteria across the intestinal wall), and preserve gut mucosal integrity. Enteral nutrition also modulates the stress and the systemic immune response, and attenuates disease severity. Lack of feeding via the gut during critical illness may lead to atrophy of intestinal villi which could predispose the patient to translocation, increase in gut permeability, and potentially increase the risk of infection.

Question 22

Which of the following best describes the rationale for initiating enteral nutrition (EN)?
A. It may be implemented in patients who cannot or will not eat adequately.
B. It is reserved for malnourished patients with an intact gastrointestinal tract.
C. It should be implemented regardless of a patient’s hemodynamics.
D. It is commonly used for nutrition support in hospice patients.

Answer 22

A. It may be implemented in patients who cannot or will not eat adequately.

Enteral nutrition may be implemented in patients who cannot or will not eat adequately. Prior to initiating EN, important factors such as ethical issues, goals of care, quality of life, risks and benefits of therapy, the patient’s clinical status, diagnosis, and prognosis should be considered. The initiation of EN is not an emergency and should only be started when patients are fully resuscitated and/or hemodynamically stable.

Question 23

Hospital-prepared enteral nutrition formulas should be stored at approximately what temperature?
A. 4° C (39° F)
B. 6° C (43° F)
C. 8° C (46° F)
D. 10° C (50° F)

Answer 23

A. 4° C (39° F)

To prevent microbial growth and contamination, hospital prepared formulas should be stored at 4° C (39° F). The danger zone for food contamination falls between 5 and 57 degrees Celsius (41° and 135° F).

Question 24

Lactose is a common ingredient in which type of enteral formula?
A. Semi-elemental adult formula
B. Standard adult formula
C. Standard infant formula
D. Elemental infant formula

Answer 24

C. Standard infant formula

Lactose is routinely used in standard infant formula to mimic the carbohydrate found in human milk. Most adult medical nutritional products are lactose-free due to the prevalence of lactose intolerance in many populations and because lactase production may be decreased during illness. Elemental infant formulas use corn syrup solids as the carbohydrate source which also do not contain lactose.

Question 25

Which of the following is the best initial enteral feeding regimen for a critically ill adult?
A. Full strength formula initiated at low rate
B. Diluted formula initiated at low rate
C. Full strength formula initiated at goal rate
D. Diluted formula initiated at goal rate

Answer 25

A. Full strength formula initiated at low rate

Research has failed to show a benefit to diluting enteral formulations, and the act of dilution may increase the rate of feeding intolerance by creating an environment that supports microbial growth. Dilution of enteral formulas during initiation may also result in a long period of inadequate nutrition. Generally, a starter regimen for enteral nutrition includes beginning the enteral formula at full strength at a lower rate and then advance to goal rate as tolerated.

Question 26

A 74 year old male patient with history of Alzheimer’s dementia and dysphagia requiring enteral nutrition as sole source of nutrition presents to hospital with fever, hypotension, poor skin turgor and dry mucus membranes. His height is 5’9” and weight is 67 kg. He is receiving 1200mL free water per day from enteral nutrition formula and 400mL from free water flush. His estimated calorie needs are 1800 kcal/day. How should his fluid needs be calculated?
A. 20 mL per kg
B. 1 mL per calorie intake
C. 1 mL per calorie calculated
D. 30 mL per kg

Answer 26

D. 30 mL per kg

The typical formulas utilized to estimate water requirements are energy based (e.g. 1 mL/kcal required) or a weight based per kg body weight (e.g. 25-35 mL/kg). For individuals over the age of 65, some experts discourage the use of energy-based formulas and instead recommend 30mL/kg with a minimum of 1500mL per day. Weight based formulas may lead to fluid overload in patients with severe cardiac issues or kidney disease. Additional fluid should be provided for individuals with severe diarrhea or emesis; large draining wounds; paracentesis losses; drain, high gastric, fistula, and ostomy outputs; and persistent fevers. Any formula to estimate water requirement is only an estimate; fluid balance and hydration status should be closely monitored.

Question 27

What is the most important intervention to reduce the risk of pulmonary aspiration during gastric tube feedings?
A. Elevate the head of bed 30 to 45 degrees.
B. Provide mouth care every 2 to 4 hours.
C. Turn the tube feeding off when repositioning the patient.
D. Hold tube feedings for a gastric residual > 200 mL.

Answer 27

A. Elevate the head of bed 30 to 45 degrees.

Raising the head of bed 30 to 45 degrees is the most important intervention to decrease esophageal and pharyngeal reflux of gastric contents to decrease the incidence of aspiration. The patient must be properly positioned in the bed for effectiveness. Oral hygiene is another intervention to reduce the risk of aspiration. There is no benefit to holding the tube feeding during brief periods of supine positioning or elevated gastric residuals.

Question 28

A patient is admitted with a traumatic brain injury and upon assessment it is determined that the patient will require enteral nutrition for the next three weeks. Which of the following is the preferred method of feeding tube placement?
A. Laparoscopic
B. Open surgical
C. Nasoenteric
D. Percutaneous endoscopic

Answer 28

C. Nasoenteric

Placement of a feeding tube via the open surgical route, laparoscopically, or endoscopically is not without risk. Risks include bleeding, anesthesia complication, bowel perforation, and infection. Although complications can occur with nasally placed tubes, they are much less common. If a feeding tube is required short term (i.e. less than 4 - 6 weeks), a nasally placed tube is the preferred method.

Question 29

Which of the following is an advantage of a gastrostomy feeding tube compared to a nasogastric feeding tube?
A. Reduced incidence of aspiration
B. Appropriate for long term feeding
C. More successful delivery of calories
D. Reduced incidence of gastric perforation

Answer 29

B. Appropriate for long term feeding

When enteral feeding is required for more than four weeks, gastrostomy feeding tubes are preferred. Feeding through a gastrostomy tube does not reduce aspiration risk. Provided the nasal feeding tube does not become frequently displaced and occluded, the calories delivered by both methods are similar. Gastric perforation is greater with a gastrostomy placed tube than a nasal placed tube.

Question 30

What is the gold standard for determining proper position of a feeding tube placed at the bedside?
A. Radiographic confirmation
B. pH testing for aspirate acidity
C. Aspiration of enteric contents
D. Air sufflation and auscultation over the gastric bubble

Answer 30

A. Radiographic confirmation

Radiographic confirmation after insertion of a nasoenteric feeding tube is the gold standard for determining proper placement of a nasogastric tube. Recent studies suggest that radiographic confirmation of placement may not be required when electromagnetic imaging technology is utilized for placement. Auscultation, pH testing, aspiration and capnography still require radiographic confirmation. Auscultatory methods cannot distinguish tubes improperly placed in the lung or coiled in the esophagus from tubes properly positioned. The pH and aspirates from a feeding tube have not been shown to be reliable as a single marker for tube tip location.

Question 31

A 45-year-old male was admitted with chronic stage IV pressure injuries, sepsis and acute respiratory failure requiring mechanical ventilation. The patient’s BUN is stable, he has no additional excess GI losses via drains or tubes. A polymeric high protein enteral nutrition formula was started on day 1 of admission. On day 7 of admission, the primary care team requested an evaluation of the protein dose provided by the enteral nutrition. Enteral nutrition was the patient’s sole source of nutrition and provides 136 grams (1.5gm/kg) protein per day. What is the best method to assess protein adequacy?
A. BUN level
B. Pre-albumin level
C. Nitrogen balance study
D. Wound healing

Answer 31

C. Nitrogen balance study

After injury, sepsis or critical illness, protein turnover rates, synthesis and breakdown are increased. Pre-albumin is significantly affected by inflammation and renal function making it a poor indicator of nutrition or protein status. Wound healing may serve as a long-term indicator that protein needs are being met but is not effective in the acute setting. Protein needs are often estimated using grams per kilogram of weight but recommendations on the optimal or ideal amount are highly debated. Nitrogen balance studies are currently considered the gold standard for assessing adequacy of protein intake in the hospitalized patient. Nitrogen balance is calculated by subtracting nitrogen output from nitrogen intake. Nitrogen output is derived using urinary urea nitrogen and requires a 24-hour urine collection. Nitrogen intake is calculated from the patient’s enteral and/or parenteral intake. It is worth noting that there are limitations to the nitrogen balance study. Many factors can affect its accuracy including renal dysfunction, errors in estimating intake/output or ostomy losses. Though other methods to assess protein turnover exist they are more expensive and invasive. Nitrogen balance = Nitrogen intake - nitrogen output. Nitrogen output (g/day) = urinary urea nitrogen (mg/100mL) X urinary volume (L/day)/100 + 20% of urinary urea losses + 2g (estimated other nitrogen from skin, GI losses).

Question 32

Which of the following is a desirable feature of skin-level or low-profile enteral access devices?
A. They are more comfortable and cosmetically appealing
B. They can be placed only as an exchange tube
C. They are used solely for gastric access
D. They can be used for feedings and medications

Answer 32

A. They are more comfortable and cosmetically appealing

Skin-level or low-profile devices are often more comfortable and cosmetically more appealing for patients. These devices are less visible under clothing. They contain anti-reflux valves, and do not require tape to secure them to the abdomen. Skin-level or low-profile devices require an access connector prior to the administration of medications or feedings which requires adequate manual dexterity. They can be placed as an exchange tube or at the time of initial tube insertion. Newer devices are available for both gastric decompression and/or jejunal feeding. These devices are held in place with an inflated internal balloon or a solid silicone internal retention bolster.

Question 33

A diabetic patient presents with early satiety, bloating, occasional vomiting, and extensive weight loss. After a thorough GI workup, the patient is diagnosed with gastroparesis. Which type of enteral formula would be more efficacious in this patient?
A. Standard, polymeric
B. High fiber
C. Concentrated, high protein, elemental
D. High fat

Answer 33

A. Standard, polymeric

Most patients with gastroparesis will tolerate a standard, polymeric formula. A concentrated formula may be used for those patients sensitive to volume. High fat and high fiber enteral formulas may decrease or delay gastric emptying, exacerbating gastroparesis symptoms. Elemental formulas are typically indicated for patients with malabsorptive syndromes and/or pancreatic insufficiency. High protein formulas may be used for wound healing and in critical care formulations.

Question 34

Which of the following medications would be appropriate to crush and deliver via an enteral feeding tube?
A. Nifedipine XL
B. Metoprolol immediate release
C. Enteric coated aspirin
D. Diltiazem CD

Answer 34

B. Metoprolol immediate release

Only immediate release tablets should be crushed for administration via an enteral feeding tube. Enteric coated or film coated tablets do not crush well and tend to clump and increase the risk of clogging the tube. Modified release dosage forms (often designated with abbreviations such as XL, XR, SR, CD, etc.) are inappropriate to crush and give via enteral feeding tube because crushing these dosage forms destroys their modified releasing properties. This may lead to an excessive dose of the drug being released at one time (instead of slowly over a longer period of time), which can lead to adverse effects and has even been reported as a cause of death.

Question 35

Placement of a jejunostomy feeding tube would NOT be beneficial for which of the following conditions?
A. Gastroparesis
B. Pancreaticoduodenectomy (Whipple)
C. Short bowel syndrome
D. Chronic pancreatitis

Answer 35

C. Short bowel syndrome

Jejunal feeding would not be beneficial in a patient with short bowel syndrome. Infusion of enteral formula into the jejunum will result in increased stool output and decreased absorption. Slow continuous infusion into the stomach is recommended to maximize absorption and increase intestinal transit time. Jejunal feeding may be beneficial to patients with gastroparesis, post Whipple, and chronic pancreatitis.

Question 36

Tube feedings can be effectively used in which of the following conditions?
A. Intractable vomiting
B. High output GI fistula
C. Open abdomen
D. Paralytic ileus

Answer 36

C. Open abdomen

Enteral nutrition (EN) has been found to be safe and to potentially reduce time to definitive abdominal closure, enterocutaneous fistula output, and infectious complications in patients with an open abdomen. It is suggested to start EN within the first 24-48 hours postinjury. While it can be used for most open abdomen patients, ongoing concern for bowel ischemia and excessive vasopressor requirements may be reasons to avoid EN in this population, but in most instances EN is beneficial and appropriate. Intractable vomiting, high output distal GI fistula and paralytic ileus are all contraindications for EN.

Question 37

Which of the following patient populations would most likely have difficulty tolerating a polymeric enteral formula?
A. Crohn’s disease
B. Chyle leak
C. Gastroparesis
D. Celiac disease

Answer 37

B. Chyle leak

Elemental enteral formulas, which contain individual amino acids and contain <2-3% of total calories from long-chain fatty acids, are ideal for patients with chyle leaks. The goal of nutritional management of patients with chylous effusions is to reduce the quantity and duration of chyle loss. Nutrition management should be started as soon as the chyle leak is suspected. Some controversy exists as to whether patients should be placed directly on parenteral nutrition. However, most investigators recommend determining the patient’s response to an elemental low fat diet before initiating parenteral nutrition. Patients with Crohn’s or celiac disease most often tolerate formulas with intact macronutrients. In severe Crohn’s disease cases refractory to medical management, trial of an elemental diet may be necessary. Patients with gastroparesis most often tolerate polymeric enteral formula fed into the jejunum.

Question 38

In a patient with fat malabsorption, an enteral product containing which of the following can provide a concentrated source of energy?
A. Medium chain triglycerides
B. Free amino acids
C. Fructooligosaccharides
D. Long chain triglycerides

Answer 38

A. Medium chain triglycerides

Medium chain triglycerides (MCT) are absorbed directly into the bloodstream and enter the portal circulation bypassing the need for pancreatic enzymes, bile, bile transport in the lymphatic system, and carnitine dependent transport into the mitochondria. Because of this, MCT can be used to provide a concentrated source of energy to patients with fat malabsorption or damage to lymphatic vessels.

Question 39

Drugs in microencapsulated bead or pellet form are most effectively administered through large-bore feeding tubes when mixed with
A. orange juice.
B. ginger ale.
C. oral electrolyte solution.
D. warm water.

Answer 39

A. orange juice.

An acidic juice such as orange juice can reduce the risk of microencapsulated beads or pellets sticking to the tube. The tube should be flushed with 30 mL water before and after administration of the drug-juice mixture to avoid physical interactions between the acidic juice and the EN formulation. Mixing drugs with carbonated beverages such as ginger ale may be problematic due to physical drug-nutrient interaction with the EN formulation. The use of water or an oral electrolyte solution to administer granules may cause them to become sticky and adhere to the tube, thereby increasing the risk for feeding tube occlusion.

Question 40

A 56 year old female with dysphagia who is afebrile and weighs 60 kg is on a standard 1 mL/kcal enteral formula at 180 mL/hr over 10 hours nightly. Which of the following volumes of water flushes would best meet her daily estimated fluid requirements?
A. 100 mL
B. 300 mL
C. 600 mL
D. 1000 mL

Answer 40

B. 300 mL

Daily fluid requirements in an afebrile enterally fed patient can be estimated using 30-40 mL/kg or 1 mL/kcal. For this patient, an initial estimate of her daily water requirement would be 1800 mL which corresponds to 30 mL/kg and 1 mL/kcal. Standard enteral formulas are ~84% free water so she would receive ~1.5 L of water from the formula. The remainder (300 mLs) can be given as flushes and/or boluses. Any formula to estimate water requirement is only an estimate; fluid balance and hydration status should be closely monitored.

Question 41

A patient with acute respiratory distress syndrome (ARDS) receiving enteral nutrition will benefit most from
A. supplemental arginine.
B. formulas containing omega-6 fatty acids.
C. formulas containing omega-3 fatty acids.
D. avoidance of overfeeding.

Answer 41

D. avoidance of overfeeding.

Acute respiratory distress syndrome (ARDS) is associated with an inflammatory response leading to diffuse alveolar damage and lung capillary endothelial injury. Inflammatory
mediators, including prostaglandins and leukotrienes derived from arachidonic acid metabolism have been implicated in both acute lung injury (ALI) and ARDS. Formulas containing omega-3 fatty acids may down regulate the inflammatory response through the production of less inflammatory prostaglandins and leukotrienes. Based on published guidelines, it is recommended that patients with ARDS and severe ALI be placed on an enteral formulation characterized by an anti-inflammatory lipid profile. Studies published in 2011 following the release of these guidelines found that enteral supplementation of omega 3 fatty acids did not result in improved biomarkers of inflammation or better clinical outcomes. Similarly, a meta-analysis published in 2014, also found no additional benefits. Overfeeding has been shown to increase the work of breathing and lead to prolonged mechanical ventilation.

Question 42

Which of the following is an indication to place a gastrojejunostomy feeding tube?
A. Esophageal cancer
B. Dysphagia
C. Gastroesophageal reflux
D. Diabetic gastroparesis

Answer 42

D. Diabetic gastroparesis

Gastroparesis is an indication for placing a gastrojejunostomy feeding tube versus a gastrostomy tube. The jejunostomy tube bypasses the stomach thus preventing nausea and vomiting during feeding. The gastric portion can be used for decompression. Research has not supported the need for placement of a gastrojejunostomy tube in patients with gastroesophageal reflux or dysphagia. Gastric feeding should be the initial therapy with esophageal cancer, so there is no need for the jejunal arm of the feeding tube.

Question 43

Which of the following is LEAST likely to be problematic for placement of a percutaneous endoscopic gastrostomy (PEG) tube in a patient with liver disease?
A. Ascites
B. Coagulopathy
C. Gastric varices
D. Hepatitis C

Answer 43

D. Hepatitis C

The presence of ascites at the time of tube placement may prevent the gastric and abdominal walls being in close proximity which results in the inability of the trocar to pass through the stomach wall. Ascites may also lead to a poor seal between the abdominal and gastric wall allowing the egress of ascites fluid or the passage of the feeding formula into the peritoneal cavity. Therefore, the presence of ascites is a relative contraindication for PEG placement. Appropriate assessment of risks vs. benefits of tube feeding must be made regarding esophageal and gastric varices, coagulopathy, hepatic encephalopathy, ascites, fulminant hepatic failure, and portal hypertension. The cause of liver failure itself, such as hepatitis C, does not affect the decision in placement of a PEG.