Introduction to Enteral Nutrition Flashcards
Elemental enteral formulas containing ___ amino acids and <___-___% of total calories from long-chain fatty acids are best for chyle leaks
-Individual
-2-3%
These formulas are specifically designed to minimize chyle loss.
When should nutrition management be started for suspected chyle leaks?
As soon as the chyle leak is suspected
Early intervention is key to effective management.
True or false: Patients with Crohn’s or celiac disease most often do not tolerate formulas with intact macronutrients.
False!
Patients with Crohn’s or celiac disease most often tolerate formulas with intact macronutrients.
Patients with these conditions may benefit from a different nutritional approach.
What dietary trial may be necessary for severe cases of Crohn’s disease that are refractory to medical management?
Trial of an elemental diet
This approach can help in managing severe symptoms.
Patients with gastroparesis most often tolerate polymeric enteral formula fed into the ___.
Jejunum
This method helps bypass issues related to gastric emptying.
Jejunal feeding in short bowel syndrome causes ____ stool output and ____ absorption
-Increased
-Decreased
Short bowel syndrome leads to a compromised ability to absorb nutrients effectively.
What EN regimen is recommended to maximize absorption in patients with short bowel syndrome?
Slow continuous infusion of EN into the stomach
This method helps increase intestinal transit time.
In which conditions might jejunal feeding be beneficial?
- Gastroparesis
- Post Whipple
- Chronic pancreatitis
These conditions may require different nutritional strategies due to altered digestive processes.
What is the main advantage of direct PEJ over PEG-J?
Less potential for migration or flipping back into the stomach
This refers to the stability of the feeding tube placement.
What complication is more likely to occur with a PEG-J (vs. a direct PEJ) ?
Gastric outlet obstruction, because it crosses the pylorus
This is due to the PEG-J method crossing the pylorus.
Is there a difference in bleeding risk between the PEJ and PEG-J methods?
No difference in bleeding risk
Both methods have similar risks regarding bleeding.
What is a disadvantage of direct PEJ placement?
Difficulty in placement
This may limit the availability of the technique in many institutions.
Modular products increase the ___, ___, or ___ content of the feeding regimen
Protein, calorie, or fiber
What should modular products be mixed with for administration?
Water according to package directions, supplements, or foods on meal trays.
True or False: Modular products can be added directly to the enteral nutrition formula.
False.
Fill in the blank: Modular products are available for use in addition to selected _______ or enteral regimens.
oral
What is a preferred source of energy for patients with burns during the stress response?
Increased breakdown of lean muscle tissue
What do patients with burns lose from open wounds?
Protein
When should protein intake for burn patients be increased?
Until significant wound healing is achieved
True or False: Patients with burns do not require additional protein intake.
False
What is the preferred method for administering tablets in tube fed patients?
Crush tablets and mix with water
This method helps ensure proper delivery of the medication.
Why is it important to flush the tube with water before and after each medication?
To avoid physical interactions between medications and between medications and formula
Flushing helps maintain the integrity of the medication delivery.
Many liquid medications are hyperosmolar which can lead to ___ and/or may have high viscosity which can lead to ___ ___
-Diarrhea
-Tube clogging
Hyperosmolar solutions can draw water into the intestines, causing loose stools.
What should be done to liquid dosage forms before administration?
Diluted with water
Dilution can help mitigate issues related to hyperosmolality and viscosity.
What is the gold standard for determining proper placement of a nasogastric tube?
Radiographic confirmation after insertion of a nasoenteric feeding tube.
This method is considered the most reliable for verifying correct placement.
Which methods of tube placement still require radiographic confirmation?
Auscultation, pH testing, aspiration, and capnography.
These methods alone are not sufficient for confirming proper placement.
What limitation do auscultatory methods have in confirming tube placement?
Cannot distinguish improperly placed tubes in the lung or coiled in the esophagus from properly positioned tubes.
This highlights the need for more reliable verification methods.
Have pH and aspirates from a feeding tube been shown to be reliable for tube tip location?
No, they have not been shown to be reliable as a single marker for tube tip location.
This raises concerns about their use as standalone verification methods.
What type of fluid can be administered to reduce the risk of microencapsulated beads sticking to the tube?
An acidic juice such as orange juice
What is the recommended volume of water to flush the tube before and after administering drugs?
30 mL
What may be problematic when mixing drugs with carbonated beverages?
Physical drug-nutrient interaction with the EN formulation
What can happen if granules are administered via feeding tube with water or an oral electrolyte solution?
They may become sticky and adhere to the tube
What risk is increased by granules adhering to the feeding tube?
Feeding tube occlusion
What is the main benefit of post pyloric feeding compared to gastric feeding?
Reduced gastric residual volume and reflux
Post pyloric feeding may lead to better digestion and less discomfort for patients.
What are the positive outcomes of small bowel feeding?
- Increased protein delivery
- Increased energy delivery
- Shorter time to target rate
These outcomes suggest that small bowel feeding may be more effective in meeting nutritional goals.
True or false: post-pyloric feeding tubes are effective for the prevention of aspiration pneumonia.
False! Adequately powered trials are not available to support prevention of aspiration pneumonia.
What are the most common reasons for occlusion of feeding tubes?
Inadequate flushing, improper medication administration, formula precipitates
These factors can lead to feeding tube blockages and complications in patient care.
What effect do fiber-containing formulas have compared to fiber-free formulas?
Increase risk for physical drug interactions
This is important to consider when selecting enteral feeding options.
Does the fat or water content of enteral formulas affect the risk of physical interaction with drugs?
No, it does not seem to affect the risk
However, high fat formulas may alter drug absorption.
What potential issue can high fat formulas cause in drug administration?
Alter drug absorption through delayed gastric emptying
This can impact the effectiveness of medications delivered via feeding tubes.
What are the methods of placing a “permanent” feeding tube?
- Open surgical route
- Laparoscopically
- Endoscopically
These methods vary in invasiveness and technique.
What are the risks associated with placing a feeding tube?
Bleeding, anesthesia complication, bowel perforation, infection
These risks highlight the potential complications that can arise during the procedure.
What is the preferred method for short-term feeding tube placement?
Nasally placed tube
This method is recommended for durations of less than 4 - 6 weeks.
What factors related to tube feeding can contribute to diarrhea?
High osmolality, rapid bolus technique, compromised albumin levels
These factors can affect fluid balance and gastrointestinal function.
Alpha-2 adrenergic agonists are a class of drugs that has significant ___ effects?
Antimotility
An example is clonidine.
What types of drugs may cause diarrhea?
Hypertonicity (improve muscle control), direct laxative action (e.g. sorbitol- or magnesium-containing preparations), or increased susceptibility to infectious enteritis (antibiotics).
Name 2 important interventions to decrease esophageal and pharyngeal reflux of gastric contents?
- Raising the head of bed 30 to 45 degrees
- Oral hygiene
This intervention helps to decrease the incidence of aspiration.
True or False: There is benefit to holding the tube feeding during brief periods of supine positioning or elevated gastric residuals.
False - There is no benefit to holding the tube feeding during brief periods of supine positioning or elevated gastric residuals.
Holding tube feeding during these conditions does not provide any benefits.
What risk may increase if feeding occurs before hemodynamic stability in critically ill patients?
The risk of intestinal ischemia.
Blood perfusion of the ___ may be compromised in a patient who is still requiring high doses of vasopressor medications to maintain blood pressure.
Gut
Even though EN may be provided with caution to patients on chronic, stable low doses of vasopressors
-under what conditions should EN be withheld?
- Hypotensive (mean arterial blood pressure <50 mm Hg)
- Increasing vasopressor needs
- Hemodynamically unstable.
What should be monitored in patients on vasopressors receiving EN for 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
What action should be taken if signs of intolerance are observed in patients on EN?
EN should be held until symptoms and interventions stabilize.
___ ___ ___ is associated with an inflammatory response leading to diffuse alveolar damage and lung capillary endothelial injury.
Acute respiratory distress syndrome (ARDS)
How may omega-3 fatty acids affect the inflammatory response in ARDS?
They may down regulate the inflammatory response through the production of less inflammatory prostaglandins and leukotrienes (which are inflammatory mediators in ALI/ARDS)
What type of enteral formulation is recommended for patients with ARDS and severe ALI?
An enteral formulation characterized by an anti-inflammatory lipid profile
What did studies find regarding enteral supplementation of omega-3 fatty acids?
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.
What effect does overfeeding have on patients with ARDS?
Increases the work of breathing and leads to prolonged mechanical ventilation
What are the 3 methods to prevent respiratory misplacement during tube insertion?
- 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
- Have the patient swallow small sips of water
This intervention helps facilitate proper tube placement and prevents misplacement into the respiratory tract.
How does proper patient positioning and sipping water help with during tube feed placement?
- Proper sitting position narrows the airway passage to facilitate esophageal placement
- Having the patient swallow during insertion decreases the risk of placing tube into the larynx
Proper positioning is crucial for successful tube insertion.
What is the role of IV metoclopramide in tube insertion?
It is a prokinetic agent that may assist with transpyloric tube passage
Metoclopramide helps in promoting gastric motility.
Medium chain triglycerides (MCT) are absorbed directly into the ___ and enter the ___ circulation
-Bloodstream
-Portal
MCT absorption bypasses the need for ___ enzymes, ___, ___ transport in the lymphatic system, and ___ dependent transport into the mitochondria.
-Pancreatic
-Bile
-Bile
-Carnitine
Because of the way MCTs are absorbed, they can be used to provide a concentrated source of energy to patients with ___ malabsorption or damage to ___ vessels.
-Fat
-Lymphatic
What are the 2 typical formulas utilized to estimate water requirements?
- Energy based (e.g. 1 mL/kcal required)
- Weight based per kg body weight (e.g. 25-35 mL/kg)
Energy-based formulas relate fluid needs to caloric intake, while weight-based formulas relate needs to body weight.
What is the recommended fluid intake for individuals over the age of 65?
30 mL/kg with a minimum of 1500 mL per day
Some experts discourage the use of energy-based formulas for this age group.
___ based fluid formulas may lead to fluid overload in patients with severe cardiac issues or kidney disease.
Weight
Fluid overload can exacerbate existing health conditions.
In what conditions should additional fluid requirements should be considered?
- Severe diarrhea or emesis
- Large draining wounds
- Paracentesis losses
- Drains
- High gastric, fistula, and ostomy outputs
- Persistent fevers
These conditions increase fluid loss and may necessitate additional fluid intake.
What are the 3 branched-chain amino acids (BCAAs)?
- Leucine
- Isoleucine
- Valine
What condition are BCAAs promoted for use in?
Hepatic encephalopathy
How do BCAAs help in hepatic encephalopathy?
They clear ammonia in the skeletal muscles, decreasing cerebral ammonia levels
What effect do BCAAs have on aromatic amino acids (AAAs)?
They reduce the uptake of AAAs across the blood-brain barrier
Patients with liver failure have ___ levels of AAAs compared to BCAAs
Higher
Name the 3 aromatic amino acids (AAAs) that may be elevated in liver failure.
- Tyrosine
- Tryptophan
- Phenylalanine
What is the consequence of the altered ratio of AAAs to BCAAs in the brain that occurs in liver disease?
More AAAs enter the brain and contribute to production of false neurotransmitters
Do high-BCAA formulations alter patient outcomes compared to standard enteral formula?
No evidence suggests they alter patient outcomes
When would a high BCAA formula be appropriate?
To patients with encephalopathy unresponsive to standard medical therapy
Research concludes that closed-system enteral formulas can hang for a maximum of ___ hours based on manufacturer guidelines.
48 hours
Define “ready to feed” enteral products
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 of EN formula___ as manipulation and handling of the formula and administration set increase.
Increases
Open systems are limited to a hang time of ___-___ hours to decrease risk of contamination
8-12 hours
Are liquid or powdered formulas more prone to contamination?
Compared to liquid formulations, powdered formulas are more susceptible to contamination because they require more manipulation during preparation
What type of enteral formula system has the lowest risk of contamination?
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 ___-___ hours.
Hang times for closed systems range from 24-48 hours.
Name 3 benefits to early EN feeding
- May prevent the occurrence of bacterial translocation (the passage of bacteria across the intestinal wall)
- Preserve gut mucosal integrity
- EN modulates the stress and the systemic immune response (which can decrease disease severity)
What are the 3 disadvantages of 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
- Potentially increase the risk of infection
Who may benefit from semi-elemental and elemental formulas?
Patients with known malabsorptive disorders or intolerance to polymeric formulations
These patients exhibit signs and symptoms of malabsorption.
What has been the conclusion regarding the evaluation of peptide-based formulas?
The use of peptide-based formula has not been extensively evaluated and results are contradictory
Two studies found reduced diarrhea, while others found increased or unchanged diarrhea.
True or false: ESPEN does not recommend routine use of elemental formulas in Crohn’s disease, ulcerative colitis, or short bowel syndrome
True
This recommendation is based on clinical guidelines.
What are some potential causes of diarrhea aside from enteral formula?
- Medications
- Rapid infusion of formula or fluid
- Small intestinal bacterial overgrowth
Does Metoprolol administration require alteration in tube feeding schedules?
No
Which 4 medications’ bioavailability may be altered with enteral nutrition?
- Warfarin
- Phenytoin
- Carbamazepine
- Fluoroquinolones (e.g., ciprofloxacin)
How long is enteral feeding often held before and after medication administration to reduce interactions?
Up to two hours
What type of formula will most patients with gastroparesis tolerate?
A standard, polymeric formula
Most patients with gastroparesis can manage a standard formula without significant issues.
What type of formula may be used for patients with gastroparesis who are sensitive to volume?
A concentrated formula
Concentrated formulas provide nutrition in smaller volumes.
What types of enteral formulas may exacerbate gastroparesis symptoms?
High fat and high fiber enteral formulas
These formulas can decrease or delay gastric emptying.
For which patients are elemental formulas typically indicated?
Patients with malabsorptive syndromes and/or pancreatic insufficiency
Elemental formulas are broken down into simpler nutrients for easier absorption.
What are two conditions that may require a high-protein formula?
High protein formulas may be used for wound healing and in critical care formulations.
High protein content supports tissue repair and recovery.
___ is routinely used in standard infant formula to mimic the carbohydrate found in human milk.
Lactose
Most adult medical nutritional products are lactose-free due to the prevalence of lactose intolerance in many populations and because ___ production may be decreased during illness.
Lactase
Elemental infant formulas use ___ ___ solids as the carbohydrate source which also do not contain lactose.
Corn syrup
What are the tow most important factors in assessing the adequacy and efficacy of enteral tube feedings in pregnancy?
Maternal weight gain and fetal growth
True or false: There is no correlation between infant birth weight and maternal weight.
False! There is a strong correlation between infant birth weight and maternal weight
What does a positive nitrogen balance suggest?
Positive nitrogen balance is important in assessing provision of adequate protein.
Is albumin a useful indicator of nutrition status in pregnancy?
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.
What are 5 associated benefits of nasogastric feeds and jejunal feeds?
- Significant reduction in infectious morbidity
- Decreased hospital length of stay
- Reduced need for surgical intervention
- Reduced multiple organ failure
- Decreased mortality
True or false: pain relapse is often noticed with nasogastric feeds when compared to parenteral nutrition
True
Why can a PEG not be placed if a patient has ascites?
Ascites is considered a relative contraindication to percutaneous endoscopic gastrostomy (PEG) placement because of the increased risk of complications such as peritonitis.
Would partial gastrectomy, prior PEG or obesity be a contraindication to a PEG placement?
Provided adequate transillumination is found during endoscopy, partial gastrectomy, prior PEG, and obesity are not contraindications to placement.
The osmolality of gastrointestinal secretions is approximately ___ mOsm/kg.
300
A formula that is isotonic would have a ___ osmolality to gastrointestinal secretions.
Similar
A 2.0 kcal/mL formula would have a osmolality of ___-___ mOsm/kg
700-800
A 1.0 kcal/mL formula would have a osmolality of ___-___ mOsm/kg
300-350
A 1.2 kcal/mL formula would have a osmolality of ___-___ mOsm/kg
400-450
A 1.5 kcal/mL formula would have a osmolality of ___-___ mOsm/kg
500-600
The best type of long term feeding tube for a patient with gastroparesis would be a ___
Gastrojejunostomy feeding tube (versus a gastrostomy tube).
Would a gastrojejunostomy tube for patients with gastroesophageal reflux or dysphagia be appropriate?
Research has not supported the need for placement of a gastrojejunostomy tube in patients with gastroesophageal reflux or dysphagia
What would be the recommended long term feeding tube for a patient with esophageal cancer?
Gastric feeding should be the initial therapy with esophageal cancer, so there is no need for the jejunal arm of the feeding tube.
When enteral feeding is required for more than ___ weeks, gastrostomy feeding tubes are preferred.
Four
True or false: Feeding through a gastrostomy tube does not reduce aspiration risk
True
Would a G-tube provide better calorie provisions than an NGT?
Provided the nasal feeding tube does not become frequently displaced and occluded, the calories delivered by both methods are similar.
Risk of gastric perforation is ___ with a gastrostomy placed tube than a nasal placed tube.
Greater
What may prevent the trocar from passing through the stomach wall during tube placement?
The presence of ascites
Ascites can create a separation between the gastric and abdominal walls.
What can result from ascites during PEG placement?
A poor seal between the abdominal and gastric wall
This may allow egress of ascites fluid or passage of feeding formula into the peritoneal cavity.
Appropriate assessment of risks vs. benefits of tube feeding must be made with the following disease states:
- Esophageal varices
- Gastric varices
- Coagulopathy
- Hepatic encephalopathy
- Ascites
- Fulminant hepatic failure
- Portal hypertension
Each of these factors can impact the safety of tube feeding.
Does the cause of liver failure, such as hepatitis C, affect the decision for PEG placement?
No
The underlying cause does not influence PEG placement decisions.
True or false: The initiation of EN is not an emergency and should only be started when patients are fully resuscitated and/or hemodynamically stable.
True
Daily fluid requirements in an afebrile enterally fed patient can be estimated using ___-___ mL/kg or ___ mL/kcal.
-30-40 mL/kg
-1 mL/kcal
Standard enteral formulas are ___% free water
84%
Describe the benefits of skin-level or low-profile EN access devices?
Skin-level or low-profile devices are often more comfortable and cosmetically more appealing for patients. These devices are less visible under clothing.
Skin-level and low-profile EN access devices contain anti-___ valves, and do not require ___ to secure them to the abdomen.
-Reflux
-Tape
Why might a skin-level or low-profile device be inappropriate for certain patients?
Skin-level or low-profile devices require an access connector prior to the administration of medications or feedings which requires adequate manual dexterity
When can a skin-level or low-profile access device be placed?
They can be placed as an exchange tube or at the time of initial tube insertion.
Can low-profile or skin-level access devices be used for feeding and decompression?
Yes! 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.
To prevent microbial growth and contamination, hospital prepared formulas should be stored at ___° C (___° F).
4° C (39° F)
The danger zone for food contamination falls between ___ and ___ degrees Celsius (___° and ___° F).
-5 and 57 degrees Celsius
-41° and 135° F
Only ___ release tablets should be crushed for administration via an enteral feeding tube
Immediate
What are the risks of administering enteric coated or film coated tablets via feeding tube?
They do not crush well and tend to clump and increase the risk of clogging the tube.
What types of tablets are inappropriate to crush and give via enteral feeding tube?
Modified release dosage forms (often designated with abbreviations such as XL, XR, SR, CD, etc.)
What are the risks with administering modified release dose tablets via a feeding tube?
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.
What type of endoscopic placement has the highest percentage of success rate for transpyloric passage?
Both fluoroscopic and endoscopic placements have the highest percentage of successful transpyloric passage
What are the pros/cons of the use of weighted tips in tube feed placement?
Weighed tips wouldn’t facilitate feeding tube placement but might help reduce chance of post-pyloric tubes curling back into the stomach.
What has research shown about diluting enteral formulations?
Research has failed to show a benefit to diluting enteral formulations.
What negative effect may dilution of enteral formulas have?
Dilution may increase the rate of feeding intolerance by creating an environment that supports microbial growth.
What can result from diluting enteral formulas during initiation of tube feeds?
It may result in a long period of inadequate nutrition.
After injury, sepsis or critical illness, ___ turnover rates, synthesis and breakdown are increased
Protein
___ is significantly affected by inflammation and renal function making it a poor indicator of nutrition or protein status.
Pre-albumin
Is wound-healing a good marker of protein-adequacy?
Wound healing may serve as a long-term indicator that protein needs are being met but is not effective in the acute setting.
What is the gold standard for assessing adequacy of protein intake in the hospitalized patient?
Nitrogen balance studies
Describe how to calculate nitrogen balance
-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.
What factors can affect the accuracy of a nitrogen balance study?
-Renal dysfunction
-Errors in estimating intake/output
-Ostomy losses.
The most influential factor in determining tolerance of enteral nutrition in pancreatitis is disease severity as measured by ___ scores.
APACHE II scores.
Does NPO duration affect enteral tolerance in pancreatitis?
Studies have shown poor tolerance in patients NPO for greater than or equal to 6 days prior to initiation of enteral feeding.
Serum ___ levels are routinely used to measure tolerance of parenteral rather than enteral nutrition in patient’s with pancreatitis
Triglyceride
What are the benefits of enteral nutrition in patients with an open abdomen?
EN has been found to be safe and to potentially reduce time to definitive abdominal closure, enterocutaneous fistula output and infectious complications
In open-abdomen patients: it is suggested to start EN within the ___-___ hours after post injury.
24-48
True or false: EN can be given to patients with intractable vomiting, high output distal GI fistula and paralytic ileus
FALSE. Intractable vomiting, high output distal GI fistula and paralytic ileus are all contraindications for EN.
