GI: nutrition Flashcards
Refeeding syndrome occurs when ___A____ is introduced after a period of prolonged starvation.
It is characterised by __B___, __C___, __D___ and __E___ dysfunction
The biochemical marker is ___F____.
It can be avoided by recognition of those at risk and __G____
Refeeding syndrome occurs when ___CARBOHYDRATE___ is introduced after a period of prolonged starvation.
It is characterised by __HEART FAILURE__, __OEDEMA__, RESP and NEURO dysfunction
The biochemical marker is __HYPOPHOSPHATEMIA__
It can be avoided by recognition of those at risk and __PREVENTATIVE MEASURES__
Who is at risk of refeeding syndrome?
1 or more:
BMI <16 kg/m2
little or no nutritional intake >10 days
low phosphate / magnesium before feeding
unintentional weight loss >15% in 3-6 months
2 or more:
BMI <18.5 kg/m2
unintentional weight loss >10% over 3-6 months
little or no nutritional >5 days
Hx of alcohol abuse or drugs (incl. insulin, chemo, antiacids, diuretics)
Before commencing re-feeding what is it essential to start first?
What else is helpful to prescribe as it is a co-factor in carb metabolism?
Essential to replenish phosphate stores with an IV phosphate infusion before starting refeeding.
Also give parenteral multivitamins as they are an important co-factor in carbohydrate metabolism.
What should be checked rigorously until full feeding has been established
Phosphate
Magnesium
Potassium levels
Re-introduction of diet must be slow, give an example of caloric regime?
may be as low as 5-10kcal/kg/day
What is the Enhanced liver fibrosis blood test?
First line recommend investigation for investigating non-alcoholic fatty liver disease
What happens when reintroduce carbohydrate to the starved state?
Insulin is released in response causing:
Increased glucose uptake
Increased uptake of magnesium, potassium, phosphate and water into cells
increased thiamine use.
results in:
Hypophosphateaemia
Hypokalaemia
Hypomagnesaemia
Thiamine deficiency
Sodium and water retention
Explain why re-feeding syndrome causes fluid shifts, reduced tissue oxygenation and impaired cardiac function?
Uptake of phosphate, potassium, magnesium and water into cells. Sodium is pushed out of cells and the phosphate stores are depleted causing fluid shift which causes oedema.
Hypophosphataemia reduces the production of ATP and impairs function of cardiac muscle.
In addition 2,3-DGP is reduced in red cells and this decreases the ability of red cells to deliver oxygen to tissues.
The combined effect of fluid shifts can cause acute congestive cardiac failure
Biochemical hallmark of refeeding syndrome?
Low: phosphate, magnesium, potassium
What is parenteral nutrition?
Nutrition which is delivered to a patient without accessing or utilising the gastrointestinal tract. By definition, PN is delivered intravenously
When is PN used?
PN is used when the gut is:
Inaccessible
Blocked
Failing.
The gut may inaccessible due to an oesophageal tumour, blocked due to small bowel obstruction or failing following massive intestinal resection
How do you work out calories in a bag of Parenteral nutrition ?
- Convert the amount Nitrogen on the bag to protein calories by multiplying the grams of Nitrogen given on the bag by 25.
- Add this to the lipid and glucose calories given on the bag
e.g. Nitrogen = 12 g
Lipid = 550 Kcal
Glucose 1000 kcal
so:
12g x 25 = 300 (protein calories)
+ 550 (lipid)
+ 1000 (glucose
= 1850kcal in total
When is PN feeding used?
PN is used when the gut is:
Inaccessible - e.g. oesophageal tumour
Blocked - e.g. small bowel obstruction
Failing - e.g. following massive intestinal resection
Can someone be on both Parenteral and Enteral nutrition?
In many situations a patient may be receiving both as a bridge to full enteral nutrition. This is why the term ‘Total Parenteral Nutrition’ or ‘TPN’ is inappropriate as PN is not always ‘total’
How is Parenteral nutrition given? over what time frame?
Prolonged infusion over 12-24 hours via a central venous catheter which feeds directly into central vein e.g. Subclavian vein, SVC, RA
Either by:
PICC line (longer as it is peripherally inserted through vein in the arm via basillic or cephalic vein )
or
Hickman Line (inserted into chest vein e.g. jugular vein or subclavian vein)
Why is a central venous catheter (CVC) used for Parenteral nutrition?
it needs to be a large vein to prevent thrombosis and damage to vessel wall that could be caused if inserted in a small peripheral vein.
CVC is a long flexible cannula that sits with its tip in a large vein
What is in Parenteral nutrition solution?
Why must it be kept covered?
PN is a solution that contains water, glucose, nitrogen, lipid, electrolytes, vitamins and trace elements- nourishes and hydrates.
Must be kept covered as sensitive to daylight can be degraded by sunlight
can be cloudy (if lipid added) or clear (if no lipid added)
What are complications of PN ?
- Biochemical
- Mechanical
- Infectious
- Biochemical:
Electrolyte disturbance
fluid overload
hyperglycaemia
abnormal liver function (carb overload) - Mechanical:
Thrombosis
Line fracture
Line occlusion
Pneumothorax (on CVC insertion)
Air embolus (if line left open)
3 Infectious:
CVC related bacteraemia
CVC related sepsis
What is the MUST tool?
‘MUST’ is a five-step screening tool to identify adults, who are malnourished, at risk of malnutrition
(undernutrition), or obese.
It also includes management guidelines which can be used to develop
a care plan.
- Outline the MUST tool steps .
Malnutrition Universal screening tool
Step 1: Measure height and weight to get BMI
Step 2: Note % unplanned weight loss and score using table
Step 3: Establish acute disease effect and score (if patient acutely ill and there is likely to be no nutritional intake for > 5 days = 2)
Step 4 : add scores to see risk
Step 5: see guidelines to develop care plan
- Outline the management guidelines based on the MUST tool score
Score 0 - low risk
Repeat screening
e.g. weekly in hospital, annually in community for >75.
Score 1 - Medium risk
Observe and document dietary intake for 3 days
Repeat screening
Score 2 or higher
Refer to dietician / nutritional support team
set goals and increase intake
All risk categories:
Treat underlying condition
Advise on food choices, eating and drinking when
necessary.
Record malnutrition risk category.
Record need for special diets
