Enteral Nutrition Flashcards
Why enteral vs. parental?
If the gut works use it
What feeds are included in enteral nutrition?
The term enteral refers to the GI tract. Tube feeding or oral feeds or both could be the route of feeding.
Under what conditions might tube feeding be neccessary?
EN is first modality for feeding people in critical care unit
* Swallowing problems
* Nerve disease
* Trauma
* Patient is unconscious
* Stroke
* Severeburns
What is the main indication for EN?
If patient is unable to meet fluid and nutritional needs by oral intake alone for a prolonged period or if its unsafe to eat orally due to a high risk of aspiration of food contents into the lung.
What are other indications for EN?
- Hypermetabolism when unable to meet total nutritional needs through oral intake
- Altered nutrient metabolism where requirements for specific macronutrients may be unique (such as MCT in liver disease, altered needs for amino acids in patients with inborn errors of metabolism) that cannot be met with diet alone.
- Oral supplementation (energy boosting) when decreased appetite due to illness, medical treatment
- When the patient experiences severe feeding inefficiency; a condition by which the investment of energy to consume a meal outweighs the potential nutritional value of intake.
How can EN be used as therapy?
- Usually supportive therapy (to promote improved nutritional status)
- Can be used as primary therapy used to treat disease (Crohn’s Disease)
Contraindications to EN
- Can meet at least BMR orally, try oral supplement strategies first
- Adults: Expected to need less than 5-10 days
- Children: expected to need less than 24-48 hours
- Severe acute pancreatitis; may feed carefully be below Ligament of Trietz
- High-output proximal fistulas; where IV replacement of losses difficult (> 2L)
- Intractable diarrhea or vomiting (especially when chemotherapy places patient at high risk for upper GI bleed)
- Complete bowel obstruction; with partial bowel obstructions can feed distal to obstruction very carefully
- Severe coagulopathy where risk for GI bleeding is high
- Severe Portal hypertension
- Abdominal wall infection
- Massive Ascites
Access devices for EN feeding
Short term feeding (< 8 weeks/ 8-12 weeks)
* Nasogastric (nose to stomach
* Naso-duodenal (nose to duodenum)
* Nasojejunal (nose to jejunum)
Longer term feeding (endoscopic or radiological placement)
* Gastrostomy (G-tubes) (directly into stomach)
* Gastro-duodenal (directly into stomach to duodenum)
* Gastro-jejunal (directly into stomach to duodenum)
* jejunostomy - directly into jejunum but not commonly used (very breakable)
What is dumping syndrome?
Gastrointestinal Disorder where large amounts of partially digested food reach the small intestine (hyperosmolar syndrome).
* Could be feeding undigested proteins for instance into small intestine which can bring in a lot of fluid rapidly and may take fluid supply from brain to GI causing disturbances. Need to consider if at risk for this.
* Need to avoid hyperosmolar formulas with dumping syndrome.
What are symptoms of dumping syndrome
- Nausea
- Weakness
- Sweating
- Palpitations
- Diarrhea
Syncope
What is the
* plaement
* aspiration risk
* dumping risk
* removal
* tolerance
for naso-gastric, naso-duodenal, and naso-jejunal?
What is an indication for jejunostomy?
Typically inserted if there is a blockage at the pylorus which precludes the ability to insert a G-J tube.
* Are placed surgically
* They are thinner; and can break more readily.
* Otherwise, the risk for aspiration and dumping syndrome are the same as GJ
What are the types of enteral feeding regimens
- Supplemental vs total support
- Bolus vs intermittent bolus vs continuous feeds
Differences between Bolus vs intermittent bolus vs continuous feeds
- Bolus feed: over 15 minutes – 30 minutes (feed is slowed down to prevent vommitting)
- Intermittent bolus: 1-2 hours
- Continuous feeds: >2 hours (pump regulates delivery at same rate)
What is a bolus feed?
The bolus method is a way to send formula through your feeding tube using a catheter syringe. A catheter syringe does not have a needle. It has a hole with a plunger in it. You pull up formula through the hole in the syringe. Then you push the formula into your feeding tube with the plunger.
Advantages and disadvantages of bolus feed
- Advantage: Short time, easy to administer, inexpensive (no pump required)
- Disadvantage: potential GI intolerance (if too much and too fast)
Advantages and disadvantages of continous feed
- Advantage: Potentially ↑ GI tolerance, ↓ risk of aspiration, gastric residual (reduced risk of vomitting)
- Disadvantage: costly; requires pump, less freedom
GI complications of tube feeding
- Nausea, vomitting
- large gastric residual
- diarrhea
- constipation
comp
Factors that result in nausea and vomiting
- large gastric residual
- Improper tube location or integrity
- rapid infusion rate, hyperosmolar formula
Factors that result in large gastric residules
- If the feed is stopped and the patient aspirates the same amount back then gave too much
- Hyperosmolar formula, high fat content of formula,
- gastroparesis (delayed gastric emptying)
Factors that lead to diarrhea
- medication (sorbital)
- lactose intolerance
- nutrient malabsorption
- bacterial overgrowth (from colon into SI)
- inadequate fibre
- rapid infusion rate
- hyperosmolar formula
- hypoalbuminemia (GI tract sloughing off protein)
- formula is too cold
Factors that may lead to constipation
- dehydration
- fecal impaction
- obstruction
- inadequate fiber
- decreased activity
- medications (analgesics)
- intestinal dysmotility
- aging patients
Metabolic complications of tube feeds
- dehydration
- increased serum electrolytes
- decreased serum electrolytes
- hyperglycemia
- hypokalemia/ hypophosatemia
Factors that may lead to dehydration
- Fever, infection, inadequate fluid, excessive weight loss, drug therapy
- Usually not related to tube feeding but might need to increase fluid if weight loss or change in drug therapy
Factors that might lead to increased serum electrolytes
High electrolyte content of formula, excess fluid losses, inadequate fluid intake, renal failure, drug therapy
* formula may not be made correctly, not adding the right amount of water
Factors that might lead to decreased electrolytes
Excessive fluid intake, water retention (SIADH or inappropriate secretion of anti-diruretic hormone), inadequate formula electrolytes, drug therapy
* usually coinciding medical condition such as head trauma
Factors that might lead to hyperglycemia
Metabolic Stress, Diabetes, excess glucose intake, drug therapy
* improperly made formula or underlying medical status
Factors that might lead to hypokalemia/ hypophosphatemia
Underfed patients can develop this so when fed CHO to someone who hasn’t had for a long time get surges of insulin and get increased uptake of glucose drivig ATPase and promotes K, phosphates and Mg going into the cell
* Refeeding Syndrome
* medications (diuretics, phosphate- binding antacids)
* Excessive losses (diarrhea, large wounds, renal losses)
Mechanical complications of tube feeding
- clogged tube
- nasal irritation/ erosion
- tube displacement
- skin infection
Factors that might lead to a clogged tube
Excessive residue in formula, inappropriate mixing of meds administered in tube
* probably biggest issue nurses deal with
Factors that might lead to nasal irritation/ erosion
Improper taping of tube, prolonged use of ng tube
Factors that might lead to tube displacement
Migration of tube into esophagus, duodenal junction
Factors that might lead to skin infections
- Skin too moist
- Leakage around tube (acid secretion)
- Mechanical irritation
- from tape
How do enteral formulas differ?
- Osmolality
- Digestibility
- Energy and protein density
- May alter in other macronutrient composition
- Lactose content
- Viscosity
- Fat content
- Free Water Content; 70-85% (more concentrated = more more calories = less free water and thicker)
What is osmolality?
Amount of free particles per unit of solution
* Water moves from a dilute solution (low osmolality) to a concentrated solution (high osmolality)
* The greater the number of particles in solution = increased osmolality
* For a given concentration, the smaller the particle size = increased osmolality.
Effect of osmolality on EN formula
- Can influence fluid balance
- Fluid imbalance can lead to diarrhea, nausea, GI distress
osmolality vs. osmolarity
- Osmolality: by weight; # of osmoles solute/kg solvent (preferred)
- Osmolarity: by volume; # of osmoles solute/L solution
Osmolality of body fluids
~300 mOsm/kg
* The body tries to keep the osmolality of the stomach and intestinal contents equal.
Osmolality of milk, orange juice and sherbert
What is the reccommended osmolality of foods given in EN?
270-320 is ideal for formula or at least <450
* >450 starts to draw fluid from surrounding tissue and may have GI dysfunction
Osmolality effect of carbohydrates
- If high molecular weight = large particles (ie. starch) → low osmolality.
- If low molecular weight = small particles (ie. sugars) → high osmolality.
osmolality effect of protein
- Large particles → minimal effect
- Small particles (ie. amino acids) → high osmolality
osmolality of fats
Do not form solution in water → very minimal effect (unless medium chain)
osmolality of electrolytes
Small particles (ie. K+ Na+) → high osmolality
What is osmolality mainly effected by?
osmolality and tolerance mainly affected by
* simple sugars, amino acids and electrolytes
What might help someone who cant eat enough at meals?
may be necessary to provide supplements
* milkshakes, eggnogs, skim milk powder
* Meal replacements: Bars & other high protein, calorie snacks
* More nutritionally complete products: ie. Boost, Ensure
Need to consider if they are nutritionally complete. These are temporary and short term. Should not displace oral intake with these products. Want to optimize food intake with whatever they can take it safely and enjoyably.
Types of enteral formulas
- Polymeric - intact protein and some MCT
- semielemental - semi broken down to facilitate nutrient absorption
- elemental - totally broken doen to AA (severe GI dysfunction)
- Specialized - hypermetabolism, disease specific, immune enhancing
Content of semi-elemental and elemental
Indication for Use: short bowel, severe GI inflammation, liver disease, Crohns
* protein and lipid predigested and broken down to facilitate nutrient absorption
* Protein; either as smaller peptides or amino acids
* Fat; may contain MCT
Energy content of EN for adults
Energy density varies from 1-2 kcal/mL
* Higher energy density; typically for fluid restricted patients or patients with hypemetabolism
* higher energy formulas often have higher osmolarity and may be harder to tolerate
protein content of EN in adults
Protein concentration can vary from 0.04 g/mL – 0.08 g/mL
What are nutrient modules?
Ways to to increase caloric/ protein density of enteral formulation
* fibre
* CHO
* protein
* fat
fibre nutrient modules?
May want to add fiber to promote normal bowel function
* Bemnifiber, pectin, Beneprotein
* Usually syringed in; need to make sure given water after since it is a bit sticky
* rarely added to tube feed because it can increase osmolarity quite a bit
protein nutrient modules?
protein (Pro-mod)
* Caution: Increases solute load, increases caloric density
* $$$
CHO nutrient modules
Add CHO
* Polycose ($$)
* caloreen
* 1/5 osm of glucose, minimal taste
Fat nutrient modules
Add fat modules
* Corn oil (~8 kcal/ml), ($)
* Microlipid (4.5 kcal/ml) ($$$)
* MCT oil (7.6 kcal/ml), more easily digested/absorbed ($$$)
* usually canola oil is added since it is typically healthier
