Malnutrition Flashcards
What is malnutrition?
a state resulting from lack of uptake or intake of nutrition leading to altered body composition and body cell mass resulting in diminished physical and mental function and impaired clinical outcome from disease
What is disease related anorexia?
loss of appetite from pathophysiological mechanisms and modification of central regulation of feeding behavior
What is the cost of malnutrition in england per year?
19.6 billion
How do we screen for malnutrition?
malnutrition universal screening tool - screen for adult malnutrition
IS NOT DIAGNOSIS
What are the limitations of MUST?
miss malnourished populations ie in ascites
What does MUST screen for?
risk for malnutrition based on BMI, unplanned weight loss and acute disease
How is nutrition assessment done?
anthropometry biochemistry clinical history nutrition requirements social and physical state
What is anthropometry?
measuring the physical measures of a persons size
ie scales, measuring circumference of arms etc, CT, hand grip strength etc
Which patients need nutritional support?
malnourished = BMI less than 1.5
or unintentional weight loss greater than 10% original body fat across 3-12months
or bmi less than 20 with unintentional weight loss over 5%
risk of malnutrition = eaten little or nothing, have a poor absorptive capacity and/ or high nutrient loss or increased nutritional need from catabolism
What is artificial nutritional support?
provision of enteral or parenteral nutrients to treat or prevent malnutrition
What is enteral nutrition?
tube feeding
What is parenteral nutrition?
intravenous delivery of nutrients, electrolytes and fluid into venous blood
What are the complications of enteral nutrition?
pH greater than 5.5 needs to be followed up by a chest x ray examined by a professional
mechanical problems like misplacement, blockage and buried bumper
metabolic problems like hyperglycaemia or deranged electrolytes
GI problems like aspiration, nasopharyngeal pain, laryngeal ulceration etc
When is parenteral nutrition prescribed?
an inadequate or unsafe oral or nutritional intake
or a non functioning, inaccessible or perforated gastrointestinal tract
How does paraenteral nutrition given?
through central venous catheter - at the superior vena cava and right atrium
What are complications associated with paraenteral nutrition?
mechanical - pneumothorax, haemothorax, thrombosis, arrythmia
metabolic - deranged electrolyte, hyperglycaemia, abnormal liver enzymes, oedema, hypertriglyceridaemia
catheter related infections
What is albumin?
synthesised in the liver
What is low albumin associated with?
poor prognosis
What is meant by albumin being a negative acute phase protein?
decreased plasma albumin associated with increased inflammation
What cytokines inhibit albumin synthesis?
interleukin 6 and tumour necrosis factor
Why does albumin decrease with inflammation?
inflammatory stimulus leads to activation of monocytes and macrophages resulting in release of cytokines which downregulate production of albumin. degradation and transcapillary loss of albumin also increase during this state
What is refeeding syndrome?
a biochemical shift and clinical symptoms occur in malnourished individual on reintroduction of oral, enteral or parenteral nutrition
Outline the physiology behind starvation
during starvation there is reduction in insulin and glucagon and glycogen stores are used -> and metabolism shifts to use of ketones and decrease use of amino acid to spare skeletal muscle breakdown + decrease in basal metabolic rate -> loss of fat and decrease of potassium magnesium and phospahate, (serum concentration is retained) increase of sodium, intracellular and extracellular water + thiamine defienciency is likely
Outline the physiology behind refeeding syndrome
- reintroduction of carbohydrate creates secretion of insulin which needs to use the sodium potassium pump with magnesium as a cofactor
- this drive influx of potassium and efflux of sodium and fluid from cells in extracellular space
- carbohydrate and insulin secretion drives phosphate into cells as its required for energy storage as ATP
- increased cellular uptake of glucose, potassium, magnesium and phosphate but reduced extracellular concentrates - hypokalaemia, hyponatremia
- thiamine is coeznyme in carbohydrate metabolism
- low electrolytes and thiamine resulting in refeeding oedema and other clinical manifestations
