A Guide to Enteral Feeds

1
A Guide to Enteral Feeds

• Cathy Payne
• Nutrition Support Dietitian

2
Choice of Feed

• Dependent on
• Individually calculated requirements for energy,
  protein, fluid, micronutrients
• Bowel function
• Clinical condition
• Long-term vs short-term
• Supplementary or complete nutrition
• Intolerance / allergy
• Aims of feeding - ?? weight, palliation
• Availability of product

3
Choice of Feed (cont)

• Pre-packaged, sterile, nutritionally complete
  feeds should be used in preference to feeds
  requiring reconstitution, dilution or additions
  in order to reduce the risk of microbial
  contamination
• 2 main categories of feed
• Whole protein (polymeric) feeds, including
  disease specific feeds
• Elemental / peptide feeds

4
Complete Whole Protein Feeds

• Standard formulae
• High energy formulae
• Low energy formulae
• Disease specific formulae

5
1. Standard Formulae

• Provide 1 kcal/ml
• Suitable for the majority of patients
• Available with or without fibre

6
2. High energy formulae

• Provide 1.2 - 2 kcal/ml
• Suitable for patients on a fluid restriction or
  with high energy requirements
• Available with or without fibre

7
3. Low energy formulae

• Fibre containing feed providing 0.8 1.0 kcal/ml
  with the RNI of most micronutrients met in 1000
  to 1200 kcal of feed
• Suitable for patients with low energy requirements

8
4. Disease specific formulae

• Need to consider the use of these products within
  the patients clinical picture rather than solely
  by the manufacturers recommended client group.
  Examples-
• 1. Renal feeds ? sodium, potassium, phosphate
• 2. Respiratory feeds - ? fat ? carbohydrate
• 3. Immune enhancing feeds variable amounts of
  additional nutrients

9
Immune Enhancing Feeds Why are they needed?

• While standard enteral feeds can prevent
  nutritional deficiencies, support immune function
  and try to promote nitrogen balance, they cannot
  reduce the inflammatory response.
• Inflammatory response ?
• enhanced net catabolism
• rapid loss of lean body mass

10
Immune Enhancing Feeds (EXAMPLES)
11
Glutamine

• Conditionally essential amino acid
• Supplementing glutamine in catabolically stressed
  animals improves
• Nitrogen retention
• Intestinal muscle growth and repair
• Gut barrier function
• Immune cell function
• Infection resistance
• Survival
• Evidence is less conclusive in human studies

12
Arginine

• Arginine is a conditionally essential amino acid
• Necessary for T-cell growth and replication
  nitrogen retention
• Necessary precursor for nitrogen oxide production
• Hypothesised that arginine may exacerbate SIRS in
  those who are already septic this has not been
  evidenced in clinical trials

13
Dietary Nucleotides

• Structural units for DNA, RNA, ATP, cyclic AMP
  numerous other essential substances
• Immunosuppression in protein-depleted (starved)
  animals can be reversed by administering
  nucleotides. These studies do not provide
  sufficient evidence for nucleotide
  supplementation of standard diets

14
Omega-3 Fatty Acids (e.g. EPA, fish oils)

• Enhance cell mediated immune responses
• Increase resistance to infection
• Inhibit inflammation
• Inhibit platelet function
• Proven benefits with cachexic pancreatic cancer
  patients in reducing weight loss
• Suppressing inflammation might not always benefit
  the patient (? host ability to fight invading
  microorganisms)

15
Immune Enhancing Feeds Caution !!

• Majority of immune enhancing feed trials have
  studied the combined effect of a number of
  substrates rather than individual substrates
• Study control and trial feeds often contain
  different levels of nitrogen
• Selective presentation of data can mislead, e.g.
• subgroup analysis
• length of stay as end point
• Effects may be different with different patient
  groups

16
Elemental / Peptide Feeds

• Used when there is severe gut impairment
• Elemental feeds
• Provide nitrogen in the form of single amino
  acids
• Formula generally low in fat
• Absorbed easily in the first section of small
  intestine
• High osmolarity, poor palatability, expensive
• Peptide feeds
• Provide nitrogen in the form of small peptide
  chains whixch need to be broken down by the host
• Lower osmolarity, improved palatability cost

17
SUMMARY

• The decision regarding choice of feed requires
• Individual assessment of the patient carried out
  by the dietitian
• Continuous review and appropriate interpretation
  of clinical trials product literature
• One feed does not fit all

18
Any Questions