Enteral Nutrition Flashcards
Once the enteral formula is opened, how long may it be stored in a refrigerator?
1: Up to 24 hours
2: Up to 36 hours
3: Up to 48 hours
4: Up to 72 hours
3: Up to 48 hours
Opened ready-to-feed formula may be stored in a refrigerator for up to 48 hours.
References:
Marian M, Carlson SJ. Enteral Formulations. In: Merritt R, ed. The A.S.P.E.N. Nutrition Support Practice Manual, 2nd ed. Silver Spring, MD; A.S.P.E.N.; 2005:63-75.
Which of the following is not an accepted means for estimating daily fluid requirements in enterally-fed adult patients?
1: 0.5 mL/kg/min
2: 35 mL/kg/day
3: 1500 mL/m2/24 hrs
4: 1 mL/kcal consumed
1: 0.5 mL/kg/min
Any of the following methods is intended to replace urine and insensible fluid losses in enterally fed adults: 35 mL water per kg body weight per day, 1500 mL water per m2 body surface area per day, or 1mL water per kcal consumed per day. 0.5 mL water per kg body weight per minute would grossly overestimate daily fluid requirements in any patient.
References:
Dickerson RN, Brown RO. Long-term nutrition support and the risk of dehydration. NCP. 2005;20:646-653.
A 51.5 kg afebrile 55-year-old female with dysphagia is started on a standard 1.0 kcal/mL enteral formula with 85% water at 180 mL/hr over 10 hours nightly. Which of the following water flush regimens would best meet her daily estimated fluid requirements?
1: 0 mL
2: 60 mL every 8 hours
3: 90 mL every 8 hours
4: 120 mL every 8 hours
3: 90 mL every 8 hours
Daily fluid requirements in an afebrile, enterally fed patient can be estimated by using 35 mL/kg/d or 1 mL/kcal consumed. For this patient, daily estimated fluid requirements would approximate 1.8 L. The standard formula used is 85% water or provides 1.53 L water per day. The remainder may be given as a fluid bolus three times a day, this would equal 90 mL every 8 hours.
References:
Lord L, Harrington M. Enteral Nutrition Implementation and Management. In: Merritt, R, ed. A.S.P.E.N. Nutrition Support Practice Manual. 2nd ed.Silver Spring, MD; A.S.P.E.N.; 2005:76-89.
In studies comparing EN to PN in patients with severe acute pancreatitis, which of the following potential benefits of EN over PN has not been documented?
1: Decrease hospitalization length
2: Decrease mortality
3: Decrease trend of organ failure
4: Decrease infection rate
2: Decrease mortality
EN has been associated with a significant reduction in infectious morbidity, hospital length of stay, and a trend toward reduced organ failure when compared with PN. Results from individual studies suggest that EN in comparison to PN reduces oxidative stress, hastens resolution of the disease process, and costs less. A reduction in mortality has not been shown with the use of EN versus PN in severe acute pancreatitis. Insufficient data exist to determine whether EN improves outcomes over no artificial nutrition support.
References:
McClave SA, Chang WK, Dhaliwal R, Heyland DK. Nutrition Support in Acute Pancreatitis: A Systematic Review of the Literature. JPEN.2006;30:143-156
Which of the following is NOT a perceived benefit of early enteral feeding in critically ill patients?
1: Prevents the occurrence of translocation of gut bacteria
2: Reduces atrophy of intestinal villae
3: Fewer infectious complications than PN-fed patients
4: Increases intestinal permeability
4: Increases intestinal permeability
Early appropriate enteral tube feeding may prevent the occurrence of bacterial translocation (the passage of bacteria across the intestinal wall), and preserve gut mucosal immunity. Lack of feeding via the gut during critical illness may lead to atrophy of intestinal villae, which could predispose the patient to translocation, increase gut permeability, and potentially increase the risk of infection. When early TF patients were compared to PN in injured patients, the PN patients had more infectious complications.
References:
Btaiche IF, Marik PE, Ochoa J, Martindale R, Salon JE. Nutrition in critical illness, including immunonutrition. In: Merritt R, ed. The A.S.P.E.N. Nutrition Support Practice Manual. 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2005:263-270.
Which of the following parameters is not useful in assessing the efficacy of enteral nutrition in pregnancy?
1: Maternal dry weight gain
2: Fetal growth
3: Urinalysis
4: Nitrogen balance
3: Urinalysis
Maternal weight gain and fetal growth are the most important factors in assessing the adequacy and efficacy of enteral tube feedings in pregnancy. Positive nitrogen balance is important in assessing provision of adequate protein. Although a urinalysis is routinely performed in pregnancy, results of this test are used to screen patients for ecclampsia and not efficacy of enteral nutrition.
References:
Frankenfield D. Pregnancy. In: Merritt R, ed. The A.S.P.E.N. Nutrition Support Practice Manual. 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2005:343-348.
Evidence exists to show which of the following enteral formulas to be most efficacious in a patient with diabetic gastroparesis?
1: Concentrated
2: Glutamine-supplemented
3: Hydrolyzed
4: Low fat
4: Low fat
Although gastroparesis may make tolerance of tube feeding difficult, most patients tolerate jejunal feeding when isotonic, rather than hypertonic or concentrated, formulas are used. Higher fat enteral formulas have been shown to decrease or delay gastric emptying. The use of hydrolyzed (vs. intact) formulas and formulas supplemented with glutamine have not been studied in diabetic gastroparesis.
References:
McMahon MM. Diabetes Mellitus. In: Merritt R, ed. The A.S.P.E.N. Nutrition Support Practice Manual. 2nd ed. Silver Spring, MD: A.S.P.E.N.; 2005:317-323.
Lactose is a common ingredient in which type of enteral formula?
1: Semi-elemental formula
2: Standard adult formula
3: Standard infant formula
4: Elemental formula
3: Standard infant formula
Lactose is routinely used in standard infant formulation 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.
References:
Marian M, Carlson SJ. Enteral Formulations. In: Merritt R, ed. The A.S.P.E.N. Nutrition Support Practice Manual, 2nd ed. Silver Spring, MD; A.S.P.E.N.; 2005:63-75.
Which of the following patient populations would most likely have difficulty tolerating a polymeric enteral formula?
1: Crohn’s disease
2: Intestinal lymphangiectasia
3: Gastroparesis
4: Celiac disease
2: Intestinal lymphangiectasia
Patients with intestinal lymphangiectasia have compromised lymphatic flow and increased pressure in the lymphatic system. Intestinal lymph flow and lymphatic pressure is increased during absorption of long-chain fats found in polymeric enteral formulas. This results in protein leakage into the intestinal lumen. A very low fat enteral formula (< 20 g) or a formula higher in medium-chain fats may relieve pressure in the lymphatic system and reduce protein losses. Patients with Crohn’s or celiac disease most often tolerate formulas with intact macronutrients. In severe 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. These patients should be kept NPO during initial enteral trials until tolerance to feeds is established.
References:
Parrish CR, Krenitsky J, Willcutts K, et al. Gastrointestinal Disease. 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.; 2007:508-539.
In patients with pancreatitis, which of the following parameters would be LEAST important in predicting tolerance of enteral feedings?
1: Disease severity
2: Duration of NPO
3: Abdominal pain
4: Triglyceride level
4: Triglyceride level
The largest 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.
References:
Mascarenhas, MR, Divito D, McClave SA. Pancreatic disease. In Merritt R, ed. The A.S.P.E.N. Nutrition Support Practice Manual, 2nd ed. Silver Spring, MD; A.S.P.E.N.;2005; 211-230.
Which of the following best describes the rationale for initiating specialized nutrition support?
1: It may be implemented in patients who cannot, should not, or will not eat adequately
2: It may be implemented in patients who are well nourished with an intact GI tract
3: It should be implemented on an emergency basis, regardless of patient’s hemodynamic status
4: It is commonly used to treat specific disease manifestations
1: It may be implemented in patients who cannot, should not, or will not eat adequately
Specialized nutrition support (SNS) may be implemented in patients who cannot, should not, or will not eat adequately and in whom the benefits of improved nutrition outweigh the risks. SNS should be implemented in patients who are malnourished or at significant risk for malnutrition. The initiation of SNS is not an emergency and should only be started when patients are hemodynamically stable. Only in relatively uncommon circumstances is SNS used to treat specific disease manifestations.
References:
A.S.P.E.N. Board of Directors and the Clinical Guidelines Task Force. Guidelines for the use of parenteral and enteral nutrition in adult and pediatric patients. JPEN. 2002;26(1 suppl):1SA-138SA.
Tube feedings can be effectively used in which of the following conditions?
1: Intractable nausea and vomiting
2: High output proximal fistula
3: Open peritoneal cavity
4: Short bowel syndrome (<50cm) without colon
3: Open peritoneal cavity
In an open peritoneal cavity, the peritoneum is left open and the viscera are protected with a temporary dressing until the abdomen can be closed. Enteral nutrition can be effectively used in patients requiring open peritoneal cavity management after laparotomy. Parenteral nutrition may not be necessary in this population. Nutritional goals and significant cost savings can be realized by using tube feedings. Parenteral nutrition should be used in patients with high output proximal fistula, intractable nausea and vomiting, and short bowel syndrome when the patient cannot be weaned off of parenteral nutrition.
References:
Corkins MR, Scolapio J. Diarrhea. In: Merritt R, ed. The A.S.P.E.N. Nutrition Support Practice Manual. 2nd ed. Silver Spring, MD: A.S.P.E.N.:2005:203-210
Which of the following is an indication to surgically place a jejunostomy feeding tube?
1: Hyperemesis gravidarum
2: Dysphagia
3: Gastroesophageal reflux
4: Diabetic gastroparesis
4: Diabetic gastroparesis
Gastroparesis is an indication for placing a jejunal feeding tube versus a percutaneous endoscopic gastrostomy (PEG) tube. The jejunal tube bypasses the stomach thus preventing postprandial nausea and vomiting during feeding. Research has not supported the need for surgical placement of a jeujunostomy tube in patients with hyperemesis gravidarum, gastroesophageal reflux, or dysphagia.
References:
A.S.P.E.N. Board of Directors and the Clinical Guidelines Task Force. Guidelines for the use of parenteral and enteral nutrition in adult and pediatric patients. JPEN. 2002;26(1 suppl):1SA-138SA.
Which of the following is the most invasive method used to assist in placement of a nasoenteric feeding tube?
1: Corkscrew method
2: Direct fluoroscopic guidance
3: Endoscopic assistance
4: Pharmacologic stimulation
3: Endoscopic assistance
While all methods listed have a success rate of 80-95%, endoscopic placement is the most invasive technique. It requires placement of a larger instrument in addition to the feeding tube into the GI tract. Other types of methods used to assist in transpyloric placement of feeding tubes include pharmacologic stimulation of gastric peristalsis with erythromycin and metoclopramide, using a corkscrew method during inserting of the feeding tube, and direct fluoroscopic guidance.
References:
Gabriel SA, Ackermann RJ. Placement of nasoenteral feeding tubes using external magnetic guidance. JPEN. 2004;28:119-122.
How long should T-fasteners be left in place after placing a gastrostomy or jejunostomy feeding tube laparoscopically or radiologically?
1: 4-5 days
2: 10-14 days
3: 21-24 days
4: 28-31 days
2: 10-14 days
There is no incision with gastrostomy or jejunostomy tubes placed laparoscopically or radiologically. Instead, T-fasteners are used to hold the stomach or small bowel in place against the abdominal wall. The external portion of the T-fastener is called a bumper. Typically four T-fasteners are used and remain in place for 10-14 days to allow a stoma tract to form. If removed sooner, displacement may occur. If kept in longer than 10 days, local skin infection and pain may result.
References:
Worthington PH, Reyen L. Equipment and formulas for enteral nutrition. In: Worthington, PH, Ed. Practical Aspects of Nutritional Support: An Advanced Practice Guide. Philadelphia: Saunders; 2004:283-309.
Which of the following is most characteristic of a skin-level device or a button for enteral feeding?
1: Can only be used with gastrostomies
2: Does not contain an antireflux valve
3: Can be capped at skin level when not in use
4: Can only be placed in the operating room
3: Can be capped at skin level when not in use
Skin-level, low-profile, or gastric button devices are alternatives to standard gastrostomy or jejunostomy tubes. Because they are less obtrusive, they have a minimal impact on body image. Skin level devices can be capped at skin level when not in use and contain an antireflux valve to prevent backflow of fluids. Physicians, nurses, or caregivers can exchange the device for a longer size if the patient grows or gains weight. Exchange or initial placement of the device does not have to be performed in the operating room since these devices are typically inserted in a well-established stoma tract.
References:
Worthington PH, Reyen L. Equipment and formulas for enteral nutrition. In: Worthington, PH, Ed. Practical Aspects of Nutritional Support: An Advanced Practice Guide. Philadelphia: Saunders; 2004:283-309.
What is the gold standard for determining proper position of a feeding tube placed at the bedside?
1: Radiographic confirmation
2: pH testing for acidity of aspirates
3: Aspiration of obvious gastric contents
4: Air sufflation and auscultation over the gastric bubble
1: Radiographic confirmation
Radiographic confirmation after insertion of a nasoenteric feeding tube is the best method (gold standard) for determining proper placement of a nasogastric tube. Although tube placement can be confirmed by air insufflation, ascultation and aspiration of gastric contents, these methods have been reported to result in false positives resulting in tube placement in the tracheobronchial tree.
Which of the following is a CONTRAINDICATION to a percutaneous endoscopic jejunostomy tube?
1: Gastroparesis
2: Partial gastrectomy
3: Refractory celiac disease
4: End-jejunostomy
4: End-jejunostomy
Jejunal feeding would be contraindicated in short bowel syndrome when only the jejunum is remaining. Delivery of formula in this situation will result in significant diarrhea and inability to absorb adequate calories for survival. In this situation parenteral nutrition or a PEG (percutaneous endoscopic gastrostomy) tube may become necessary. Gastroparesis is the primary indication for a percutaneous endoscopic jejunostomy (PEJ). A partial gastrectomy and refractory celiac disease would not be contraindications to jejunal feeding or to placement of a PEJ.
References:
A.S.P.E.N. Board of Directors and the Clinical Guidelines Task Force. Guidelines for the use of parenteral and enteral nutrition in adult and pediatric patients. JPEN. 2002;26(1 suppl):1SA-138SA.
Compared to gastric feeding, small bowel feeding is associated with which of the following outcomes in critically ill patients?
1: Longer time to achieve target nutrition
2: Increased nutrient delivery
3: Increased gastroesophageal regurgitation
4: Increased rate of ventilator-associated pneumonia
2: Increased nutrient delivery
Based on a systematic review of studies comparing gastric and small bowel feeding methods, small bowel 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.
References:
Kattelmann KK, Hise M, Russell M, Charney P, Stokes M, Compher C. Preliminary evidence for a medical nutrition therapy protocol: enteral feedings for critically ill patients. J Am Diet Assoc. 2006;106(8):1226-1241.
Which of the following surgically placed feeding tubes can result in a thoracic duct injury?
1: Witzel gastrostomy
2: Stamm gastrostomy
3: Cervical esophagostomy
4: Needle catheter jejunostomy
3: Cervical esophagostomy
Potential complications of a surgically placed cervical esophagostomy or cervical pharyngostomy include infection, hemorrhage, aspiration, thoracic duct injury, recurrent laryngeal nerve injury, permanent fistula, and inadvertent tube dislodgement. Thoracic duct injury is not a complication of a surgically placed jejunostomy or gastrostomy because anatomically the surgeon is not operating near the thoracic duct. Cervical esophagotomy and pharyngostomy are rarely used today as a result of improved surgical techniques for placement of feeding tubes.
References:
Vanek VW. Ins and outs of enteral access: Part 2-Long term access-esophagastomy and gastrostomy. NCP. 2003;18(1):50-74.