Case 15- Nutrients 2 Flashcards
Malnutrition university screening tool (MUST)
5 steps that test risk of undernutrition
• BMI
• Unplanned weight loss over 3-6 months
• Acute disease effect- if patient is acutely ill and has had no nutritional intake for over 5 days or is likely to be, then you add 2 points.
• Determine overall risk of malnutrition by calculating the score, 0 is low risk, 1 is medium risk, 2 or more is high risk
• Action- determined by local agreed protocol.
Anthropometry- weight and percentage weight (Screening nutritional status)
A patient is indicated for nutrition support if they have:
1) BMI<18.5kg/m2 unintentional weight loss of >10% in the previous 3-6 months
2) BMI<20kg/m2 and unintentional weight loss >5% in the previous 3-6 months
Calculating BMI
BMI (kg/m^2) = weight (kg) / height^2 (m^2)
Anthropometry- BMI (screening for nutritional status)
If BMI <18.5kg/m2 patient is underweight
If BMI 18.5-25kg/m2 patient is in normal BMI range
If BMI >25kg/m2 patient is overweight
Anthropometry- mid upper arm circumference MUAC (screening for nutritional deficiencies)
Measuring the circumference of the mid point of the upper arm using a tape measure, measures mass. Useful if a person cant be weighed or their weight is not a true reflection of body mass i.e. ascites.
If MUAC is <23.5cm the patient is likely to have a BMI <20kg/m2 and may be at risk of malnutrition.
Anthropometry- skinfold thickness (nutritional screening)
Used by a trained person using skinfold callipers which have been Calibrated. Can be done at 8 different sites but most commonly the tricep skinfold (TSF). Measurements should be duplicate, longitudinal measurements identify changes in fat mass.
Centile tables are used for interpretation
Anthropometry- Mid arm muscle circumference MIAMC (nutritional screening)
MAMC is a surrogate measure of fat free mass and is calculated using MUAC and TSF (tricep skin fold thickness).
MAMC (cm) = MUAC (cm) – 3.14 x TSF (cm)
Centile tables allow measurements of changes in total body muscle mass over time
Nutritional screening- bloods
1) Haemoglobin- assess iron status, anaemia
2) Glycated haemoglobin (HbA1c)- indicates average blood sugar over a couple of months
3) Sodium- indicates hydration status and kidney function
4) Urea- high urea may indicate dehydration
5) Calcium and Phosphate- used when assessing refeeding risk, calcium is adjusted for albumin levels
6) Magnesium- low if large GI losses
7) Micronutrients- vitamins and trace elements, best measured when CRP is low as affected by infection
Nutritional screening- Clinical assessment
Diseases can cause malnutrition through increased energy requirements, reduced energy intake or increased nutritional losses. These include: Cancer, COPD, Heart failure, Crohns, liver disease, stroke, motor neurone disease, mental health issues and trauma.
Symptoms include- altered bowel movements, upper GI upset i.e. nausea, early satiety, dysphagia, lethargy.
Nutritional screening- dietary assessment
Assess nutritional requirements. In the dietary assessment you would look at the quantity and quality of food and fluid intake. As well as eating patterns, portion size, cooking methods and nutritional supplements taken.
Nutritional support- Environmental assessment
Social- ability to shop and cook. Do they need assistance with eating and drinking. Their mobility, budget restraints, limited storage facilities, meal timings and family support.
Physical- appetite, dentures, dexterity, use of cutlery, taste change, nausea, heart burn, bloating, early satiety, diarrhoea, constipation, breathing difficultes, dysphagia, food intolerances, diminished thirst and taste preference.
Refeeding risk assessment- only need one factor
- BMI- less than 16 kg/m^2
- Weight loss- unintentional weight loss greater than 15% within the last 3-6 months
- Nutritional intake- little or no nutritional intake for more than 10 days
- Blood biochemistry- low levels of potassium phosphate or magnesium prior to feeding
Refeeding risk assessment- when the patient has 2 or more of the following factors:
- BMI less than 18.5kg/m^2
- Unintentional weight loss greater than 10% within the last 3-6 months
- Little or no nutritional intake for more than 5 days
- A history of alcohol abuse or drugs including insulin, chemotherapy, antacids or diuretics
Treatment for chronic undernutrition
- Parenteral- delivery of nutrition intravenously
- Enteral- delivery of nutritionally complete feed directly into the gut via a tube
- Oral nutritional support- additional snacks, fortified food (adding nutrients to a particular food), oral nutritional supplements.
Types of fortification
- Mass fortification- general public, iron in breakfast ceral
- Targeted fortification- specific populations
- Market driven fortification- Business orientated initiative
Food fortification- what foods are given to patients lacking certain macronutriensts
- Energy (carbohydrate)- sugar, jam
- Energy (fat)- cream, butter, cheese, crème fraiche
- Protein- skimmed milk powder to milk, peanut butter
Oral nutritional supplements
- Milkshake type- nutritionally complete
- Juice-based- not nutritionally complete as no fat
- High energy powders i.e. complan and meritene- not nutritionaly complete
- Semi-solid/dysphagia ranges- thickened liquids through to puddings
- High protein- jellies, shots and milkshakes
- Low volume high concentrate- fat and or protein based products
Parenteral nutrition
Using the blood stream, via central or peripheral route. Central route is preferable as you can have more concentrated feeds but tends to be used for more long term access. Peripheral access is more short term, a PIC (periphery inserted central catheter) line can be used for concentrated food stuff as its connected to the central system.
In order to keep the gut healthy there should be some enteral nutrition even if they are relient on Parenteral
Types of enteral nutrition
You can use a nasogastric tube, gastronomy tube, nasoduodenal tube etc. These tubes can be divided into gastric or post pyloric. They can be short term or long term. The Gastrostomy and Jejunostomy tube are more long term. Some feeds are more concentrated then others. Need to be fed through a pump to ensure they are not getting too much at once.
Process of starvation
- Levels of glucose begin to fall- 24 to 72 hours, Glucagon is released and Insulin is reduced
- Glucose levels maintained by Glycogenolysis- Glycogen rarely lasts more then 72 hours
- Gluconeogenesis occurs- preferred fuel for brain, falls between 24-72 hours
- Fatty acid oxidation in the liver hepatocytes- produces ketone bodies
- BMR is reduced by reducing the action of cellular pumps- electrolytes leak across the cell membrane. Increase in extracellular water and sodium with depletion of total body K+, Mg+2 and Phosphate. Serum concentration of ions are maintained whilst intracellular stores are depleted. Na+ and fluid leak into the cell causing Na+ intolerance. Micronutrient store is depleted and thiamine deficiency is likely
Refeading pathogenesis
- In the precense of food there is a conversion to glucose as the major energy source. There is a rapid decline in gluconeogenesis and anaerobic metabolism. Insulin starts to increase, this activates the ATP pump which requires magnesium as a cofactor. Drives K+ into the cells and Na+ and fluid out of the cells. Phosphate is driven into the cell as its required for energy storage as ATP
- Causes cellular uptake of glucose, potassium, magnesium and phosphate and a decrease in extracellular concentrations. Biochemical refeeding.
- Thiamin deficiency can also occur as it’s a coenzyme in carbohydrate metabolism
Issues the patient will have if they get refeeding syndrome
- Hypophosphataemia
- Hypokalaemia
- Hypomagnesaemia
- Reduced sodium and water excretion- the extracellular fluid compartment expands
- Vitamin deficiencies- particularly thiamine
Cardiac effects of refeeding syndrome
Low PO4- altered myocardial function, arrhythma, congestive heart failure, sudden death
Low K- Arrhythmia, cardiac arrest, ECG changes
Low Mg- Arrhythmia, tachycardoa
Respiratory effects of refeeding syndrome
Low PO4- acute ventilatory failure, dyspnea
Low K- respiratory depression
Low Mg- respiratory depression
Hepatic effects of refeeding syndrome
Low PO4- liver dysfunction
Low K- exacerbation of hepatic encphalopathy