Nutritional Assessment & Enteral Nutrition. Enteral Nutrition
ENTERAL NUTRITION
10. When should enteral nutrition be considered?
Show answer
Always, but especially when a patient is unlikely to meet > 70% of nutritional needs by mouth. Patients who have sustained major head injury (Glasgow Coma Scale score < 8), major torso trauma, major trauma to the pelvis and long bones, or major chest trauma benefit from enteral nutrition. Approximately 85% of postoperative patients (even those undergoing gastrointestinal [GI] surgery) tolerate early enteral feeding (within 24 hours).
11. How do you access the GI tract for feeding?
Show answer
By blind placement of a nasogastric (NG) tube or duodenal placement of a nasoduodenal tube. More distal placement may be achieved endoscopically with a nasojejunal tube (NJ). Gastric decompression and nasojejunal feeds may be accomplished concurrently after endoscopic percutaneous endoscopic gastrostomy or jejunostomy (PEG or PEJ). Alternatively, a gastrostomy or feeding jejunostomy may be placed intraoperatively.
12. What types of enteral formulas are available?
Show answer
Polymeric enteral feedings are soy-based, lactose-free products that contain intact protein, carbohydrates, and fat. Most offer 1 kcal/mL and 37-62 g of protein per liter. Some have additional insoluble or soluble fiber. Special modifications of the standard formulas include “immune-enhancing” agents such as fish oil, arginine, glutamine, and nucleotides. “Elemental” formulas contain amino acids, di-, tri- and quatra-peptides, dextrose, and minimal fat. Several concentrated formulas (2 kcal/mL) are available for use in patients with congestive heart failure (CHF), renal failure, and hepatic failure. In general, products that are disease specific or contain nutrients in elemental form are more expensive than standard products.
13. Are specialized formulas necessary for critically ill patients with diabetes mellitus?
Show answer
No. Formulas with reduced carbohydrates and increased fat loads are marketed as being superior in maintaining glycemic control. These products have not undergone prospective, randomized, controlled trials (PRCTs) to demonstrate superior outcome in ICU patients. The use of standard high-protein formulas in an isocaloric or hypocaloric load combined with appropriate insulin therapy may be the most effective treatment for insulin resistance in stressed type 2 diabetic patients. Glycemic control associated with enhanced outcome is best achieved with insulin, as opposed to carbohydrate restriction. Furthermore, gastric feedings with high-fat formulas in diabetic patients with gastroparesis may be associated with delayed gastric emptying and increased risk of aspiration.
14. Should specialized “pulmonary” formulas be used on all patients on ventilators?
Show answer
No. Specialized high omega-6 fat formulas have been marketed to reduce CO2 production in COPD patients who are CO2 retainers. In theory, these minimize CO2 retention and facilitate weaning. However, avoidance of overfeeding is more beneficial than provision of a high-fat formula.
15. What complications are related to enteral support?
Show answer
Electrolyte abnormalities, hyperglycemia, GI intolerance, pulmonary aspiration, and nasopharyngeal erosions.
16. Should one wait for bowel sounds or flatus before beginning enteral feedings?
Show answer
No.
17. Should one delay nutrition support longer in obese patients, assuming they have increased reserves?
Show answer
No. Obese patients have more fat, but during stress, all patients become hypermetabolic and break down endogenous protein stores to mobilize amino acids for gluconeogenesis, protein production, and energy production. So, even obese individuals “auto-cannabalize.” As with normal-weight patients, obese patients require high-protein nutritional supplementation to meet increased amino acid demands. Theoretically, by providing nutritional support, protein breakdown is minimized.
18. Should enteral formulas be diluted for initial presentation?
Show answer
No. Dilution delays the attainment of feeding goals. Manipulation of the formula increases the likelihood of bacterial contamination. Furthermore, solution osmolarity is a relatively minor culprit in the incidence of diarrhea.
19. How should enteral feeding-related diarrhea be managed?
Show answer
Mild diarrhea usually requires no treatment. Moderate to severe diarrhea may require feeding reduction, antidiarrheal agents, and stool studies for Clostridium difficile. The medication profile should be evaluated for sorbitol-containing elixirs, laxatives, stool softeners, and prokinetic agents. Sanitation issues related to formula handling must be monitored. Some success has been reported with lactobacillus (yogurt) in antibiotic-associated diarrhea or with soluble fiber.
20. Do enteral feedings contain enough water to meet all fluid needs?
Show answer
Most 1-kcal/mL formulas (standard) contain 85% water by volume, and 2-kcal/mL formulas contain 70% water. Water is generally not an issue in ICU patients receiving multiple intravenous (IV) fluids and drugs. However, on the wards or in patients bound for home or postcare facilities, it is essential to write a water prescription with the tube feeding order. General guidelines for the total water needs of patients are shown in Table 8-5.
Thus, if the total calculated need for fluid is 2400 mL for a 60-kg patient and the tube feeding provided 2000 mL of free water, an order should be written to deliver 200 mL of water to the patient twice daily.
Table 8-5. DAILY WATER NEEDS IN RELATION TO AGE
21. How is enteral nutrition infused?
Show answer
Enteral nutrition is generally infused continuously, in bolus form, or cyclically. Continuous infusion is preferred in critically ill patients who require postpyloric feedings. Bolus feedings are generally used in more stable patients with gastric feedings. Cyclic feedings or nocturnal feedings benefit patients who are on concurrent oral intake and in transition to full oral support.
22. Is enteral nutrition better than total parenteral nutrition (TPN)?
Show answer
Yes. Substrates delivered enterally are better tolerated, are associated with fewer metabolic and hepatic complications, and help preserve normal mucosal (”barrier”) integrity. A review of five studies contrasting TPN with no nutrition or early enteral nutrition concluded that TPN is associated with a greater incidence of septic morbidity.
Comments
Leave a Reply
Abernathy’s Surgical Secrets, Updated Edition (Book w / Student Consult)
Author / s: Harken Alden H., Abernathy Charles, Moore Ernest Eugene
Year: 2004
Pages: 473
Publishers: Elsevier Mosby; 5th Bk & Acc edition
ISBN: 0323034160
