TPN Flashcards
What deficiencies can cause abnormal nutrient intake causing malnutrition?
Nutrient intake, Digestion, Absorption, Metabolism, Excretion/Nutrition losses
Rapidly developing malnutrition triggered by acute stress and injury, which is short lived, and resolves as patient condition improves is known as?
Acute Malnutrition
Happens because of another disease such as cancer, IBD, organ failure, and requires long term monitoring and therapy is known as?
Chronic malnutrition
What is the consequence of untreated malnutrition?
-Impaired immunity
-Decreased wound healing
-Increased complications
-Poor response to medical or surgical therapy
-Reduced growth or development of infant or child
-Death
You have a patient who has inadequate or unsafe oral intake, and a functional accessible GIT, what type of feeding would you recommend for this person?
Enteral tube feeding
You have a patient with inadequate or unsafe oral or enteral intake and a non-functional or perforated GIT. What type of feeding would you recommend for this person?
Parenteral nutrition
What does parenteral nutrition include?
Water, Amino acids, Glucose, Lipids, Vitamins, Trace elements, Electrolytes
Why might someone use parental nutrition short term?
-Post surgery if the patient is on gut rest (NBM) - for more than 7 days
-Obstruction in the gut
-Severe shock or gut infection
-Malnourished or unable to eat
Why might someone use parental nutrition long term?
-Non-functioning gut
-Not enough gut to function due to surgery
*Some patients still eat small amounts, this may or may not be permanent
If in oral diet someone has water/volume what do they have in the PN source?
Water/volume
If in someone’s oral diet they have protein what would this replace this with in PN?
L-amino acids mixture
If someone’s oral diet they have carbohydrates, what is the equivalent to this in PN?
Glucose
If someone’s oral diet they have Fat with essential fatty acids, what is the equivalent to this in PN?
Lipid emulsion with essential fatty acids
If in someone’s oral diet they have Vitamins what is the equivalent to this is PN?
Vitamins
If in someone’s oral diet they have Minerals, what is the equivalent to this in PN?
Trace elements
If in someone’s oral diet they have Electrolytes what is the equivalent to this in PN?
Electrolytes
What is the equation to work out how much water a patient would require?
Maintenance fluid = 1500ml + (20ml x each kg of weight >20kg)
What factors mean that less fluid would be given?
-Fluid overload
-High humidity
-Blood transfusion
-Drugs
-Cardiac failure
-Renal failure
What factors mean that more water should be given?
-Dehydration
-Fever
-Acute anabolic state
-High temp
-Low humidity
-GI losses
-Burns/wounds
-Blood loss
What is the equation for nitrogen?
0.2g nitrogen/kg/day
What is given for amino acids?
Nitrogen
Amino acid solutions are hypertonic to blood, what does this mean?
They should not be administered alone in peripheral circulation as they can cause damage to blood vessels.
What is the equation for how much Energy is required for a person?
25-35 non-protein kcal/kg/day
Where is energy for PN sourced from?
Lipid and Glucose (dual energy source)
Why do we need a dual energy source?
Metabolic issues can arise, as they can exceed metabolic capacity.
How many ‘g’ of anhydrous glucose provides 4kcal?
1
Why shouldn’t glucose be used alone as an energy source?
-Hyperglycaemia
-Fatty infiltration of the liver (excess glucose is converted to fatty acids)
-Excessive CO2 production
-Excessive consumption of oxygen
-Essential fatty acid deficiency
-Metabolic issues
How much lipid should a patient receive?
Patients typically receive 2.5g lipid/kg/day
What are some examples of lipid emulsions containing essential fatty acids?
Linoleic acid 52% / 8%
What examples of lipid emulsions contain other fatty acids?
*Oleic acid 22%
*Palmitic acid 13%
*Stearic acid 4%
*Other fatty acids 1%
What are the two groups of micronutrients?
Trace elements and Vitamins
What is the advantage of Lipid Emulsions?
*Large amount of energy in small amount of fluid
*Allows peripheral administration
-Isotonic
-Veno-protective effect
*Contains some fat soluble vitamins (E and K)
*Prevents/reverses essential fatty acid deficiency
What are micronutrients key role?
Intermediary metabolism as both co-factors and co-enzymes, affect enzyme activity and total metabolism
What affects micronutrient requirements?
*Baseline nutritional state on starting PN
*Increased loss
- small bowl fistulae/aspirate (Zinc rich)
- Biliary fluid loss (Copper rich)
- Burn fluid loss (Zinc, Copper, Selenium rich)
What clearance is reduced when someone is in liver failure?
Copper and Manganese
What clearance is reduced when someone is in renal failure?
Aluminium, chromium, zinc and nickel clearance
What are the commercially available products which are added into TPN?
Additrace and Decan
What are the 10 known trace elements?
1) Iron
2) Copper
3) Zinc
4) Fluorine
5) Manganese
6) Iodine
7) Cobalt
8) Selenium
9) Molybdenum
10) Chromium
What are fat-soluble vitamins stored in the body?
A - retinol
D - Ergocalciferol
E - tocopherol
K1
What are the water-soluble renally cleared vitamins?
B1 - Thiamine
B2 - Riboflavin
B6 - Pyridoxine
B12
C - Ascorbic acid
Folic acid
Panthothenic acid
Biotin
Niacin
What commercial preparation is availble for fat-soluble vitamins?
Vitilipid N Adult
What is in a TPN bag?
Amino acids (nitrogen/proteins), Glucose & Lipids (Energy and fluid), Trace elements, Vitamins, Electrolytes
What commercial preparation is available for water-soluble vitamins?
Solivito-N
What electrolytes are added according to the patients daily blood tests?
Sodium, Potassium, Calcium, Magnesium, Phosphate, Chloride, Acetate
What is the first line administration route for TPN?
Peripheral Administration when for short term.
Central Administration for longer term feeding.
How many hours before giving TPN should it be taken out of the fridge?
3 hours
How can physical stability be affected with TPN?
-Precipitation:
*Can cause fatal emboli - cannot be seen if nutrients contains a lipid.
-Lipid destabilisation
*Lipid globules may come together and coalesce, cause respiratory and circulatory blockages
-All PN fluids are passed through a filter when infused into a patient
How can Chemical stability be affected in TPN?
Vitamins undergo chemical degradation, they are sensitive to light exposure.
-Vitamin C is the least stable and used as a marker for vitamin degradation
How can Microbial stability be affected in TPN?
*High nutritious medium - growth
*Manipulations are performed using validated aseptic techniques
*Staff are trained in aseptic technique when connecting/disconnecting infusions
What do we monitor in a patient with TPN?
DAILY BLOODS
-LFT, Electrolyte, Blood glucose, Haematology, CRP, Calcium, Albumin
ALSO
Clinical symptoms, temperature, blood pressure, fluid balance, weight, nitrogen balance, lipid tolerance, acid-base profile
What are the complications when having TPN?
-Line blockages
-Line sepsis
-Thrombophlebitis
-Refeeding syndrome
What causes line blockages in TPN lines?
-Fibrin sheath forms around the line or a thrombosis blocks the tip
-Internal blockage of lipid, blood clot or salt and drug precipitates
-Line Kinking
-Blockage of a protective line filter
What is Refeeding syndrome?
*Metabolic complication when the infused nutrition exceeds the tolerance of a previously malnourished patient
What should be added to a TPN back if the patient is at risk of refeeding syndrome?
Thiamine
How many hours should the first bag of TPN be given over?
48 hours
What happens in the body in refeeding syndrome?
Fat stores are getting used up when starting TPN, the food changes the metabolising carbohydrate and instead of fat, there is a sudden increase of insulin, this decreases K and Mg causing fluid retention.
