Chapter 11: EN Formulations Flashcards
**What are EN practice recommendations from ASPEN, include what statements regarding enteral formulation selection? (3)
- *1. The accuracy of adult enteral formula labeling and product claims is dependent on formula vendors
- Nutrition support clinicians and consumers are responsible for determining the accuracy of information about adult enteral formulas.
- Interpret enteral formulations content/labeling and health claims with caution until such time as more specific regulations are in place.
EN formulas are not FDA-approved, so their claims are not regulated.
Explain carbohydrate composition for EN formulations, in general
40 - 70% of their energy as carbs; primary macronutrient
Polymeric formulas use mostly corn syrup solids as carb source
Hydrolyzed formulas use maltodextrin or hydrolyzed cornstarch as the carb. source
Most formulas do not contain lactose.
Explain fiber composition for EN formulations, in general
Guar gum and soy fiber are the common fiber sources
Soluble fiber may help control diarrhea due to its ability to increase sodium and water absorption via its fermentation byproducts, SCFAs
Insoluble fiber may help to decrease transit time by increasing fecal weight
**What are the ASPEN/SCCM recommendations related to use of fiber in EN formulations?
**They suggest that clinicians consider fiber-containing formulas if patients have persistent diarrhea.
Also, both insoluble and insoluble fiber be avoided if the patients are at a high risk for bowel ischemia and have severe dysmotility.
Why may the prebiotic fibers (in fiber-containing EN formulas) provide benefits to some patients?
Some EN formulas contain FOS (fructooligosaccharides), aka prebiotics that help promote growth of beneficial bacteria, in the distal bowel and are fermented to produce SCFAs
Explain fat composition for EN formulations, in general
Concentrated energy source, and provides essential FAs
Usually contain a mixture of LCTs and MCTs (MCTs do not provide EFAs and are also not stored, LCTs are also added)
Corn and soybean oil are the most common sources used; safflower, canola and fish oils are also used
What are structured lipids?
“are a chemical re-esterification of LCTs and MCTs on the same glycerol backbone, offering advantages of MCTs, while including enough LCTs to meet EFA needs”
Some EN formulas contain these lipids
Define hydolyzed protein
small peptides (more than 3 AA residues)
Define Semi-elemental or Elemental formulas
aka dipeptides, tri-peptides, and free AA
Any peptide greater than 3 AAs require further hydrolyzation prior to absorption
Most enteral formulations provide adequate amounts of vitamins and minerals to meet DRIs when provided in what volumes/day?
1000 - 1500 mL/day
Supplementation should be considered for patients when the enteral formula does not meet their v/m needs
(T/F) Standard enteral formulas contain modest amounts of electrolytes, typically enough to meet daily needs in most patients when the formula is provided in adequate amounts to meet DRIs.
TRUE
How much (% range) do enteral formulas contain by volume?
70 - 85%
Most patients receiving EN require an additional source of water to meet their fluid needs (IVF, additional water flushes)
Define osmolality, when referring to EN formula.
“is the concentration of free particles, molecules, or ions in a given solution, and is expresed as milliosmoles per kg of water (mOsm/kg).”
Osmolality of EN formula ranges from: 280 - 875 mOsm/kg.
As the content of free particles, ions or molecules increases in the product, so does the osmolality.
For example, formulas containing sucrose have a higher osmolality than those with cornstarch or maltodextrin.
Formulas with single AAs or high amounts of di- or tri-peptides, also have higher osmolality than those with intact proteins.
Define hypertonic enteral formulations
Osmolality greater than 320 mOsm/kg.
Are frequently blamed for formula intolerance, like diarrhea, etc. Which can result when these formulas (especially ones with sucrose) are delivered directly to the SI, causing dumping syndrome. This problem is unlikely to occur when peptide or single AAs are provided in the same manner
*Other than simple sugar-related hyperosmolality, the osmolality of an enteral formula has little to do with formula tolerance.
What is EN formula tolerance or diarrhea, most often related to? (4)
- Severity of illness
- Co-morbid conditions
- Enteric pathogens
- Concomitant use of meds administered through the enteral access device
Describe diabetes-specific EN formulas.
Lower in carbs (33 - 40%), higher in monounsaturated fat and total fat (42 - 54%) and provide more fiber (14 - 16 g/L) than standard polymeric formulas.
Rationale: Fiber will slow gastric emptying, leading to better glycemic control
What does the ADA (American Diabetes Association) recommend for DM management?
“Macronutrient distribution should be based on individualized assessment of current eating patterns, preferences, and metabolic goals”
“Ideal quantity of carbs intakes as well as insulin therapy should be individualized for each patients”
Note fiber is not usually appropriate to use in critically-ill patients
**What do North American nutrition support guidelines say for diabetic patients in the ICU?
**Does not recommend the use of diabetes-specific formulas based on the evidence available.
(T/F) Switching to a diabetes-specific EN formula is the first step in management of hyperglycemia?
FALSE: Blood glucose control should be optimized by appropriate energy provision and insulin therapy, usually insulin gtt in the ICU setting.
Providing SSI “as needed” is not effective in controlling BG within the recommended range of 140 - 180 mg/dL
**What does ESPEN/ASPEN recommend for elemental EN formula use with patients with GI issues?
**ESPEN does not recommend the routine use of elemental formulas with Crohn’s disease, ulcerative colitis, or short-bowel syndrome.
**ASPEN also recommends that routine elemental and disease-specific EN formulas be avoided in critically ill patients because no clear benefit to patient outcomes has been shown in the literature.
What does the research show for hepatic encephalopathy EN formulas?
No evidence that the use of high-BCAAs formulations alter patient outcomes compared to standard formulas.
Hepatic encephalopathy is a complication of liver failure and elevated blood ammonia, so the rationale is a formula with lower protein, increased amounts of BCAAs, and decreased amounts of AAAs were developed for this patient population.
BCAA supplementation has been associated with an increased risk of nausea and vomiting, as well
Define immune-modulating formulations (IMFs).
EN formulas that contain arginine, glutamine, omega-3 FAs, nucleotides, and antioxidants
These specific nutrients are thought to have potential to modulate the metabolic response to surgery/stress
Explain how/why the effects of arginine differs from surgical vs. non-surgical patients.
It relates to metabolism
Surgical: in patients undergoing surgery for head/neck cancers, arginine-containing formulas were associated with reduction in fistula and LOS
**What are SCCM/ASPEN guidelines for IMFs in critically ill patients?
- *1. Do not recommend the routine use of IMFs with severe sepsis.
2. Recommend IMF use be reserved for the postoperative patients in the surgical ICU.
