Parenteral nutrition Flashcards
Who needs PN?
Pre-term infants Bowel obstruction Short bowel Crohn's disease Multiple trauma Pseudo-obstruction Short term gut rest
What is the primary goal of PN?
Provide adequate calories and proteins whilst maintaining fluid balance
Prevent malnutrition and associated complications
What will PN contain?
Proteins Carbohydrate Fat Electrolytes Trace elements Vitamins A,B,C,D,E Water
What is in a triple chamber PN bag?
separate glucose, amino acid and lipid
What is in a 2 in 1 PN bag?
Aqueous ingredients only (separate lipid to aid stability)
What is in a 3 in 1 PN bag?
All ingredients in one bag (aqueous & lipid)
What is in a lipid PN bag?
Fat/lipid based ingredients (separate from aqueous)
What is in a 1 in 1 PN bag?
Amino acid and electrolyte replacement
Stability and compatibility of PN formulations are influenced by what?
Ingredients
Preparation and compounding
Containers
Storage
What can happen if PN bags are exposed to sunlight?
Breakdown of Vitamin A
When does precipitation occur?
When chemicals interact to form insoluble salts
When can precipitation occur?
When adding strong injections of calcium/magnesium/phosphate to PN without mixing between additions
What pH should PN bags be maintained at?
5.0 or above (below 6.0 to reduce precipitation)
What should be added to amino acids in PN?
macro-electrolytes
What should be done to calcium and phosphate components before mixing in PN bag?
Separate and dilute
What should be mixed before adding lipid?
amino acids and glucose
What should be added last to a PN bag?
Fat
What should be added to lipid in PN bag?
Vitamins
What should trace elements be added to in PN bags?
Glucose
Should vitamins and trace elements be separated or mixed in PN bags?
Separated
Is fat provided as an oil in water or water in oil suspension?
oil in water
What factors affect the lipid emulsion stability?
Positive ions pH Glucose conc Time Lipid emulsion dilution
Amino acids chelate with what?
cations
What container type is best for PN bags?
Multilayer
Why is PVC not ideal for PN bags?
Leaching of plasticisers
Why is EVA not ideal for PN bags?
Poor oxygen barrier
Where should PN feeds be stored?
refrigerator
How long should PN feeds be allowed to warm up for before use?
1 hour
