Ch 11: EN Formulations Flashcards
CHO sources in standard and hydrolyzed TFs
- Polymeric: corn syrup solids as CHO source
- Hydrolyzed: maltodextrin or cornstarch as CHO source
CHO in TFs
- 40-70% of energy in most formulas
- Primary macronutrient
- Contributes to osmolality, digestibility, and sweetness of enteral formulas
Common sources of fiber in TF:
guar gum and soy fiber
Soluble fiber may help control diarrhea by
increasing sodium and water absorption via fermentation byproducts (SCFAs)
Soluble fiber → SCFA in colon (energy for colonocytes) → increase intestinal mucosal growth and promote water and sodium absorption
Insoluble fiber:
may decrease transit time by increasing fecal weight
ASPEN/SCCM guidelines for fiber in TFs:
- Consider fiber-containing formula if patient with persistent diarrhea
- Avoid both types of fiber if patients are at high risk for bowel ischemia and have severe dysmotility
Cases of bowel obstruction from fiber containing formulas have been reported in critically ill patients
Fat in TFs
Concentrated energy source and provides EFAs (linoleic and linolenic acid). Mix of LCT and MCTs
* LCTs: corn and soybean oil most common
* MCTs: palm kernel and coconut oil
Advantages/disadvantages of MCT:
- Absorbed directly into portal circulation & don’t require chylomicron formation for absorption
- Do not require pancreatic enzymes or bile salts for digestion/absorption
- Cleared from the bloodstream rapidly
- Cross the mitochondrial membrane without need for carnitine (where they are oxidized to CO2 and water, therefore not stored)
- Do not provide EFAs (which is why there is a mix of LCT/MCT)
Intact proteins:
Whole protein or protein isolates –
require normal levels of pancreatic enzymes
* Mostly used- casein, soy
* Clso used- lactalbumin, whey, and egg
TF & Vitamins & DRI
Most formulas have enough vit/min to meet DRI at 1000 to 1500 mL/d of formula
Water in TF formulas
- 70-85% water by volume
- Not intended to meet total fluid needs
- Adequate hydration is needed to maintain tissue perfusion and electrolyte balance
1.0 = 83% – 85% per liter
1.2 = 81% – 82% per liter
1.5 = 76% – 78% per liter
2.0 = 69% – 72% per liter
Osmolality
The concentration of free particles, molecules, or ions in a given solution
* Expressed mOsm/kg
Osmolality of TF formulas ranges
280-875 mOsm/kg
Which is higher in osmolality?
* Sucrose, cornstarch, maltodextrin
* Single AA, di- and tripeptides, intact protein
- Sucrose mOsm/kg > cornstarch or maltodextrin
- Single AA or high amounts of di- and tripeptides mOsm/kg > intact protein
What happens when hyperosmolar formulas containing sucrose are fed to the SB?
Dumping syndrome
Unlikely to occur when peptide of single AA are provided in a similar manner
Other than simple sugar hyperosmolality, the osmolality of an enteral formula:
has little to do with formula tolerance
Food Allergies and Intolerances - TF formulas
- May contain milk, soy, con, or egg products
- Most formulas are lactose and gluten free
A clinician must evaluate available research before recommending specialized formula:
- In vitro (animal) vs in vivo (human) study
- Quality of study design:
——Prospective RCT
——Retrospective review
——Case reports - Similarity of pt pops studied to pts being cared for (demographics, clinical status, clinical environment)
- Generalizability of results
Hyperglycemia, hypoglycemia, and glycemic variability have each been associated with
morbidity and mortality
DM formulas vs standard
DM formulas are:
* Lower in CHO (33-40%)
* Higher in monounsaturated fat and total fat (42-54%)
* Provide more fiber (14-16 g/L)
What is the goal of DM formulas?
Slow gastric emptying and lead to better glycemic control
Patients with DM and gastroparesis may have difficulty tolerating DM formulas because
higher fat and fiber content
Recommendations for DM formula use:
Standard formulas used in conjunction with appropriate energy provision and insulin therapy are promoted for patients with DM or stress-induced hypoglycemia
GI d/o and malabs TF formula
Formulas usually contain: hydrolyzed proteins, MCTs, omega 3s, FOS, prebiotics, and inulin
What does the research say about peptide-based formulas in GI issues?
Contradictory research for peptide-based formulas, but it may reduce diarrhea
ASPEN & ESPEN rx for elemental formulas
- ESPEN recommends against routine use of elemental formulas in IBD and SBS
- ASPEN recommends against routine use of elemental formulas in critically ill patients (no clear benefit in patient outcome shown in literature)
TF & Hepatic Failure
BCAAs (leucine, valine, and isoleucine) have been promoted in this population in the past because they clear ammonia in the skeletal muscle, thus decreasing cerebral ammonia levels and reducing the uptake of AAAs across the blood brain barrier
Of BCAA trials, what were the results?
BCAA supplementation was found to have a beneficial effect on hepatic encephalopathy, but it didn’t lead to improvements in mortality, QOL, or nutrition-related outcomes
BCAA supplementation (ie orally)
increases N/V
Recent systematic review and meta-analysis: arginine-enriched formulas administered to H&N CA pts undergoing surgery
Associated with reduction in fistulas and hospital LOS
Metabolism of arginine differs in surgical patients vs non-surgical
Numerous reviews on IMF use in surgical/critical care populations:
decreased risk of infection, reduced length of stay, and reduced mortality
ASPEN/SCCM 2016 guidelines for IMF:
- Does not recommended routine use of IMFs with severe sepsis (arginine metabolism releases Nitric Oxide which fuels sepsis)
- Reserve IMF for post-op patients in SICU
ASPEN and SCCM recommendations for ARDS and ALI
do not recommend use of specialized formulas for ARDS/ALI
High doses of omega 6’s are not recommended in critically ill population due to pro-inflammatory properties
Optimal nutrition management in AKI includes:
- Adequate macronutrient support to correct underlying conditions
- Prevent ongoing loss of organ function
- Supplement micronutrients and vitamins during RRT
- Adjust electrolyte replacement based on degree and extent of renal dysfunction
Routine use of renal-specific EN formulas is
not necessary in CKD or AKI
2016 ASPEN/SCCM guidelines for critically ill:
- Recommend use of standard high protein formulas for patients with AKI
- Hyperkalemia or hyperphosphatemia may require a renal-specific formula
wasting conditions
Proteolysis-inducing factor causes
protein catabolism and leads to cachexia in cancer patients
wasting syndrome
Conditionally essential AA glutamine and arginine are associated with
improving immune function and wound complications when supplemented at pharmacological levels
HMB (metabolite of BCAA leucine) results in
positive patient outcomes when provided with or without arginine and glutamine
Promotes anabolism by increasing protein synthesis and inhibiting pathway that controls protein degradation
Trauma patients receiving HMB had less negative nitrogen balance
wound healing
What nutrients are associated with improved patient outcomes?
Glutamine, arginine, omega 3s, zinc, selenium, and vitamins A/C/E
Provision of IMFs (containing arginine, omega 3 FA, antioxidants, and sometimes glutamine) decreases the incidence of
Patient complications including anastomotic dehiscence
* Effects demonstrated in GI surgery and trauma populations
Multiple reviews suggest _ _ _ can assist pts at risk for PIs (NH residents, SCI, wounds) as long as other protective behaviors (weight control, exercise, healthy lifestyle) are involved)
a high protein diet and adequate serum levels of Vitamin A and zinc
