1. Enteral & Parenteral Nutrition Support
Chapter 15
Enteral & Parenteral Nutrition Support
© 2007 Thomson - Wadsworth

2. Nutrition Support Enteral Parenteral Uses the veins
Means “within or by means of the gastrointestinal tract.”
Oral
Known as tube feedings
Preferred route if have adequate GI function
Parenteral
Uses the veins
Persons with inadequate GI function
The consensus of nutrition experts is that the GI tract is more physiologically and metabolically effective than the intravenous route for nutrient utilization. Once the patient has been assessed and found to be a good candidate for enteral nutrition, the clincian selects the appropriate tube and route of access for tube placement.
Enteral access selection depends on several factors:
Anticipated length of time enteral feeding will be required
Degree risk for aspiration or tube displacement
Presence or absence of normal digestion and absorption
Whether or not there is a planned surgical intervention
© 2007 Thomson - Wadsworth

3. Algorithm for enteral vs parenteral selection.
© 2007 Thomson - Wadsworth

4. If you choose enteral nutrition support…
Must have functional GI tract
Bowel sounds
Can be used alone or as a supplement
Variety of kinds of formulas
Types
Standard ( cal/ml)
Tolerated by most patients
Hydrolyzed
Partially or fully broken down
Persons with compromised GI functioning
High calorie
Disease-specific
Modular
contain 1-2 macronutrients
A wide variety of enteral feeding products are commercially available. It takes a complex nutritional assessment to determine what type of formula a patient needs. As more products become available, with claims for pharmacologic effects, clinical trial evidence for each new product must be carefully evaluated by the clinician before a decision is made to use a formula.
In 3 studies conducted on patients in the CCU, it was found that physician ordered TF rates met % of the patients needs. Of the ordered rates patients only received 76-78% of the expected amount of TF.
Formulas are classified in a variety of ways, usually based on protein or overall macronutrient composition.
- General purpose: tolerated by most patients, usually have 1.0 – 1.2 calories per mL
- High calorie: General formula with calories per mL. Used when it is necessary to restrict fluid for patients with cardiopulmonary, renal and hepatic failure.
- Hydrolyzed: Used for those patients who have malabsorptive problems
- Disease-specific: Available for patients who have renal, hepatic, or cardiopulmonary disease; metabolic stress, immunosuppression or glucose intolerance. The use of these types of formulas is controversial.
© 2007 Thomson - Wadsworth

5. Enteral Nutrition Support
Provide Pro, CHO and Fat
Nutrient Density
Protein = 8-29% of total kcalories
Standard formulas
Carbohydrates = 40-50% total kcalories
Fat = 30-45% total kcalories
Energy Density
kcalories per mL
Standard formulas
kcalories per mL
Patients with average fluid requirements
Formulas with higher energy density
Smaller amount of fluid
Good for fluid restrictions
Protein in enteral formulas provides 8-29% of total calories. Typically TF provide polymeric forms of protein (whole proteins) but a TF formula can also contain amino acids which are derived from hydrolysis of casein, whey, lactoalbumin, or soy. These are for patients with maldigestion or malabsorption. Osmolalities will be higher in these formulas because of the hydrolyzed proteins.
Carbohydrates contribute 40-50% of total calories. Lactose is not used as a carbohydrate source in most formulas because of the high incidence of lactase deficiency in acutely ill patients.
Lipids provide 30-45% of total calories. Total calories provided by lipids is usually from corn, soy, sunflower, or safflower oils. Pulmonary formulas are typically high fat formulas intended to prevent excess carbon dioxide retention and facilitate weaning from mechanical ventilation.
© 2007 Thomson - Wadsworth

6. Feeding Routes Tube feeding less than 4 weeks Postplorically
Nasogastric
Postplorically
Nasoduodenal
Nasojejunal
These tubes are weighted or non-weighted with stylets to guide placement
Orogastric
Mouth to stomach
Good for vent patients
Tube feeding more than 4 weeks
Enterostomy
Gastrostomy
Jejunostomy
Gastric feedings are the preferred route
Easily tolerated & less complicated
Not good for patients at risk for aspiration
Nasogastric, nasoduodenal or nasojejunal routes are for short-term use of 3 to 4 weeks, a NGT passed through the nose into the stomach is appropriate. Patients with normal GI function and gag reflex tolerate this method, which takes advantage of normal digestive, hormonal, and bactericidal processes in the stomach.
- Feedings can be administered by bolus injection or intermittent or continuous infusion.
NGT is made of a soft, flexible, and well-tolerated polyurethane or silicone tube of various diameters, lengths, and design features may be used, depending on formula characteristics and feeding requirements.
- For example: A thicker formula is going to need a larger diameter tube. The lumen (space inside the tube) is measured by the french unit. 1 french = .3mm
If a tube is placed post-pylorically, what does this mean?
Percutaneous endoscopic gastrostomy (PEG) tube is a nonsurgical technique for placing a tube directly into the stomach through the abdominal wall, performed using an endoscope and with the patient under local anesthesia. Tubes are endoscopically guided into the stomach or the jejunum and then brought out through the abdominal wall to provide the access route for enteral feedings. Preferred method if feeding is estimated to last >3-4 weeks. It is possible to place a percutaneous endoscopic jejunostomy (PEJ) tube percutaneously, however, this procedure carries a higher degree of risk.
NGT placement is verified by aspirating gastric contents, pushing air into the stomach, or radiographic confirmation of the tube tip location. When soft, small-bore tubes are used, aspiration of gastric contents must be performed cautiously to prevent the tube from collapsing.
© 2007 Thomson - Wadsworth

7. © 2007 Thomson - Wadsworth

8. © 2007 Thomson - Wadsworth

9. Osmolality
A solution’s tendency to shift from one fluid compartment to another across a semipermeable membrane
Range: milliosmoles per kilogram
Isotonic: osmolality similar to blood
Hypertonic: osmolality greater than blood
The size and number of the nutrient particles in a solution define its osmolality. General purpose formulas have osmolalities between mOsm, which is close to the osmolality of body fluids. Osmolalties of nutrient-dense formulas are higher, ranging from mOsm. Hydrolyzed formulas are as high as 900 mOsm per kg of water.
© 2007 Thomson - Wadsworth

10. Enteral Nutrition in Medical Care
Preferred over parenteral
Helps maintain gut
Fewer complications
Less costly
Oral preferred over tube feedings
Less stress
Less complications
Can fully meet nutrient needs
Good for weak & debilitated patients
Nurses help patients find appealing flavors
© 2007 Thomson - Wadsworth

11. Candidates for Tube Feedings
Severe swallowing problems
Little or no appetite
GI obstructions, impaired GI motility
Intestinal resections
Mentally incapacitated
Coma
Extremely high nutrient requirements
Mechanical ventilators
© 2007 Thomson - Wadsworth

12. Feeding Tubes Soft & flexible Variety of lengths & diameters
Outer diameter measured in French units
© 2007 Thomson - Wadsworth

13. Formula Selection Need to assess Choose the one
Age
Medical problems
Nutritional status
Ability to digest & absorb nutrients
Choose the one
With the lowest risk of complications
Lowest cost
Nutrition-related factors
Energy, protein, & fluid requirements
Need for fiber modification
Individual tolerances (food allergies & sensitivities)
© 2007 Thomson - Wadsworth

14. Algorithm for enteral formula selection.
© 2007 Thomson - Wadsworth

15. What Formula? Factors to consider Electrolytes GI function Fluid
Calorie and protein density
Ability to meet needs
Type of
Protein, fat, CHO
Fiber
Electrolytes
Fluid
Viscosity
Osmolality
© 2007 Thomson - Wadsworth

16. Administration of Tube Feedings
Safe handling
Clean equipment
Clean hands
Open system
Formula needs to be transferred from original packaging to feeding container
Closed system
Formula is prepackaged
Safety guidelines
Clean can opener & lid
Refrigerate unused portions in clean, closed containers
Discard unlabeled or unused within 24 hours
Open system; hang no longer than 8-12 hour supply
Closed system; hang no longer than hour supply
© 2007 Thomson - Wadsworth

17. Tube Feeding Formula delivery Initiating tube feeding Intermittent
Formula delivery
Intermittent
Gastric, mL over minutes
Risk of aspiration
Bolus
Gastric
Delivery of <500mL every 3-4 hours
Continuous
Slowly at constant rate
8-24 hours
Noctural
Initiating tube feeding
Discuss with patient & family
Check initial placement with X-ray
Monitor its position throughout the day: can check fluid pH
The three common methods of tube feeding administration are bolus, intermittent drip, and continuous drip. Method selection is based on the patient’s clinical status and quality of life considerations. One method can serve as a transition to another method as the patient’s status changes.
Bolus – The feeding modality of choice when patients are clinically stable with a functional stomach is the syringe bolus method. Syringe bolus feedings are more convenient and less expensive than pump or gravity bolus feedings and should be encouraged when tolerated. The pt with normal gastric function can usually tolerate up to 500mL of formula at each feeding. Three or four feedings per day can provide the daily nutritional requirements for most pts.
Intermittent – All more free time compared to continuous drips. A schedule is based on four to six feedings per day administered for 20 to 40 minutes. Formula administration is initiated at 100 to 150 mL per feeding and increased incrementally as tolerated. Intermittent feedings as well as bolus feedings should not be used with patients at risk for pulmonary aspiration.
Continuous – Requires a pump. This method is appropriate for pts who do not tolerate large-volume infusions such as those occurring with bolus or intermittent methods. Patients with small bowel access should be fed by continuous drip infusion. The feeding-rate goal, in mL per hour, is set by dividing the total daily volume by the number of hours per day of administration. Feeding is started at one quarter to one half the goal rate and advanced every 8 to 12 hours to the final volume. Formulas with osmolalities between 300 and 500 can be started at full strength.
© 2007 Thomson - Wadsworth

18. Administering the Feeding
Formula volume & strength
Varies among institutions
Hypertonic fluids usually started slowly & volume gradually increased
Assess patient tolerance
Checking gastric residuals
Withdraw contents through feeding tube with syringe
Intermittent before each feeding
Continuous every 4-6 hrs
© 2007 Thomson - Wadsworth

19. Tube Feedings Supplemental water Transition to table foods
Formulas are 69-85% water
More water comes from flushes via feeding tubes
Flush before & after each bolus or intermittent feeding
Flush every 4 hours for continuous
Count as intake
Transition to table foods
Gradually shift to oral diet
Oral needs to be 2/3 of nutrient intake before discontinuing the tube
Fluid needs for adults can be estimated at 1 ml of water/kcal or 30 to 35mL per kg of usual body weight.
© 2007 Thomson - Wadsworth

20. Tube Feedings Delivering medications Complications Monitor patient’s
Need to consider diet-drug interactions
Medications can clog tubes
Continuous: stop feeding 15 minutes before & after medication administration
Complications
Nausea & diarrhea
Mechanical problems
Metabolic problems
Monitor patient’s
Weight
Hydration status
Lab test results
Dilantin
Access problems
Administration Problems
Gastrointestinal complications
- N/V
- Delayed gastric emptying
- Constipation/Diarrhea
- High Gastric Residuals
Metabolic Complications
- Refeeding syndrome
- Drug-nutrient interactions
- Glucose intolerance
- Hydration status
© 2007 Thomson - Wadsworth

21. Parenteral Nutrition Support
© 2007 Thomson - Wadsworth

22. Indications for Parenteral Nutrition
Short bowel syndrome
Severe pancreatitis
Malabsorption disorders
Intestinal obstructions or fistulas
Severe burns or trauma
Critical illnesses or wasting disorders
Bone marrow transplants
Malnourished & high risk for aspiration
© 2007 Thomson - Wadsworth

23. Venous Access Peripheral Parenteral Nutrition (PPN)
Peripheral veins
Short-term support
Patients with average nutrient needs & no fluid restrictions
Veins can be damaged
Need solutions under mOsm
Total Parental Nutrition (TPN)
Larger, central veins
Long-term support
Patients with high nutrient needs or fluid restrictions
Peripheral access refers to catheter tip placement in a small vein typically in the arm. May clinicians do not use PPN because they argue that it is short-term therapy with minimal impact on nutritional status.
Nutrient solutions not exceeding mOsm per kilogram of solvent can be infused through a routine periperhal intravenous catheter placed in a vein in good condition.
Central access refers to catheter tip placement in a large, high-bloodflow vein such as the superior vena cava; this is TPN.
© 2007 Thomson - Wadsworth

24. © 2007 Thomson - Wadsworth

25. Parenteral Solutions Contain amino acids Contain carbohydrates
All essential plus combinations of non-essential
Contain carbohydrates
Dextrose, 3.4 kcalories/gram
2.5-70% concentrations
>10% only for TPN
Contain lipids
Significant source of energy
10, 20% solutions
Often provided daily & = 20-30% total kcalories
Decreases risk of hyperglycemia from dextrose
The concentration of amino acids in these solutions range from 3 to 15% The caloric content of aa is ~ 4 calories per gram.
CHO is supplied as dextrose monohydrate in concentrations ranging from 2.5 to 70%. The dextrose monohydrate yields 3.4cal/gm.
Lipids emulsions, available in 10% to 20% concentrations are composed of aqueous suspensions of soybean or safflower oil with egg yolk as the emulsifier. A 10% solution provides 1.1 kcals/ml and a 20% solution provides 2.0 kcals/ml.
© 2007 Thomson - Wadsworth

26. © 2007 Thomson - Wadsworth

27. Parenteral Solutions Fluid Contain electrolytes Contain vitamins
Need mL/day for adults
Contain electrolytes
Sodium, potassium, chloride, calcium, magnesium, & phosphorus
Expressed in milliequivalents (mEq)
Contain vitamins
All water-soluble plus A, D, & E
K must be added separately
Contain trace minerals
Zinc, copper, chromium, selenium, & manganese
Iron is excluded
© 2007 Thomson - Wadsworth

28. Types of Parenteral Solutions
Total Nutrient Admixture (TNA)
3-in-1 solution
Also called “all-in-one” solution
Contains dextrose, amino acids, & lipids
2-in-1 solution
Dextrose & amino acids
Lipids administered separately to provide essential fatty acids
© 2007 Thomson - Wadsworth

29. Administering Parenteral Nutrition
Team effort
Physicians
Dietitians
Pharmacists
Nurses: provide direct care
IV catheters
Nurse can place in peripheral veins
Physician must place in central veins
Problems
Dislodging
Air embolism
Clotting
Phlebitis
Infection
Must use aseptic technique
© 2007 Thomson - Wadsworth

30. Parenteral Nutrition Complications
Mechanical complications
Infection and sepsis
Metabolic Complications
Gastrointestinal Complications
Mechanical – pneumothorax, air embolism, blood clotting , catheter dislodgement
Infection and sepsis
Metabolic – Refeeding syndrome, electrolyte imbalances, glucose
GI – Cholestatis, hepatic abnormalities, GI villous atrophy
© 2007 Thomson - Wadsworth

31. Parenteral Solutions Administering Discontinuing Continuous Cyclic
Critically ill
Malnourished
Cyclic
10-16 hours
Often provided at night
Check tubing & solution daily for contamination
Discontinuing
When 2/3-3/4 of nutrient needs are provided by enteral feedings, IV can be discontinued
Clear liquids
Small enteral feedings to determine tolerance
© 2007 Thomson - Wadsworth

32. Managing Metabolic Complications
Hyperglycemia
Patients who are glucose intolerant or in severe metabolic stress
Provide insulin with feedings or decrease dextrose
Hypoglycemia
When feedings are interrupted or discontinued
Taper slowly
Hypertriglyceridemia
Critically ill can’t tolerate lipid infusions
Impaired lipid clearance
Refeeding syndrome
Re-feed slowly
Life-threatening
Abnormal liver function
Long-term, can lead to liver failure
Cause unclear
© 2007 Thomson - Wadsworth

33. Managing Metabolic Problems
Gallbladder disease
Parenteral for more than 4 weeks
Sludge builds up, leading to gallstones
Cholecystokinin injections or remove gallbladder
Metabolic bone disease
Long-term parenteral lowers bone density
Alterations in calcium, phosphorus, & vitamin D metabolism
© 2007 Thomson - Wadsworth

34. Nutrition Support at Home
Candidates
Enteral
Head & neck cancers
Neurological impairments affecting swallowing
Parenteral
Portion of small intestine removed
Intestinal obstructions
Malabsorption conditions
Planning Enteral
Nasal tubes or enterostomies
Investigate cost & availability
Planning Parenteral
Sterile & aseptically prepared
Cyclic best
© 2007 Thomson - Wadsworth

35. Quality of Life Issues Economic impact Time-consuming Inconvenient
Disturbed sleep
Activities & work must be planned around feedings
Social issues
Inability to consume meals with friends & family
Inability to go to restaurants & social events
Fear, anxiety & depression
© 2007 Thomson - Wadsworth

36. Ethical Issues in Nutrition Care
Nutrition in Practice
Ethical Issues in Nutrition Care
© 2007 Thomson - Wadsworth

37. Ethical Principles & Health Care
Patient autonomy
The right to make own health care decisions
Disclosure
Fully informed of treatment’s risks & benefits
Decision-making capacity
Mental capacity to make appropriate health care decisions
Treatment benefits (beneficence) should outweigh harm (maleficence)
Distributive justice
Would care given to one patient unfairly limit the care of other patients?
© 2007 Thomson - Wadsworth

38. Life-Sustaining Treatments
Nutrition support & hydration
Cardiopulmonary resuscitation (CPR)
Defibrillation
Mechanical ventilation
Dialysis
© 2007 Thomson - Wadsworth

39. Legal Documents for End of Life Care
Living will, medical directive
Written statement specifying medical procedures desired or not desired
Advanced directive
Written or oral instruction regarding one’s preferences for medical treatment
Durable power of attorney
Another person is appointed to make health care decisions in the event of incapacitation
Do-not-resuscitate (DNR)
Order to withhold CPR in the event of a cardiac arrest
© 2007 Thomson - Wadsworth