T1 L14: Nutrient malabsorption

• What different mechanisms of disease can malabsorption cause?

  • Mal-digestion
  • Inadequate absorptive surface
  • Bile Salt Deficiency
  • Lymphatic obstruction
  • Vascular disease
  • Mucosal disease
• What is the energy balance in health?

  In health glucose primary fuel for energy – metabolism and citric acid cycle. Fat and proteins are conserved
• What is the energy balance in disease?

  BMR increases

  Appetite and activity decrease

  In disease inflammatory response – cytokines

  TNFα: Insulin resistance, glycolysis

  IL2 glucose metabolism

  IL4 lipid & glucose metabolism

  IL6 lipolysis
• What is the relationship between acute illness and growth hormone?

  during acute illness, growth hormone synthesis is stimulated to grow and repair damaged tissues

  but because of the stress response, can get anti-anabolic effect (blocked growth) -> 'anti-insulin effect'
• What is the 'anti-insulin effect' during acute illness?

  acute illness causes insulin resistance

  so many acutely ill patients present hyperglycaemia
• In terms of BMI, what kind of patients are at high risk of re-feeding syndrome?

  patients with low BMI / very skinny

  have low metabolism
• In terms of BMI, what kind of patients are in more advantage in acute illness?

  patients with low BMI

  already have low metabolism

  body already in starved state
• You need to eat food with high calories during illness because inflammation uses up a lot of energy.

  
• What are the dietary requirements in chronic illness?

  start with food - may have long term enteral feeding

  Focus on balanced diet

  Diet to:

  • increase energy intake
  • manage blood glucose
  • reduce workload of kidney
  • reduce inflammation
  • support treatment
• What are the dietary requirements in acute illness?

  start with food but consider other routes such as enteral/parenteral

  Diet to:

  • meet energy demand and reduce catabolism
  • support recovery – micronutrients & macronutrients
• What do patients with an acute illness need, and what are the feeding issues they are facing?

  Need to:

  meet energy demand

  conserve muscle mass – avoid negative nitrogen balance

  Manage blood glucose

  Issues:

  • Poor appetite or inability to eat
  • Extended periods of time nil by mouth
  • Not a priority
  • Unclear roles and responsibilities

  Be cautious with severely malnourished patients – risk of re-feeding syndrome
• What are the risk factors for re-feeding syndrome?

  Patient has one or more of the following:

  • BMI less than 16
  • unintentional weight loss greater than 15% within the last 3–6 months
  • little or no nutritional intake for more than 10 days
  • low levels of K+, phos or Mg prior to feeding

  Or patient has two or more of the following:

  • BMI less than 18.5
  • 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.
• What should be checked prior to feeding, and then daily?

  U&E, incl phosphate and magnesium
• What are the key takeaway points when dealing with nutrition in clinical scenarios?

  Make food part of your conversation in clinical practice:

  • On admission
  • At ward rounds
  • Planning for discharged
  • In GP practice
  • Supporting home care

  Need to consider the body of evidence

  Be wary of nutrition pseudoscience.

  Learn to be critical thinkers

  Leave your personal dietary beliefs at home
• What is a 'high output stoma'?

  loss of fluid and nutrients from GI tract into ileostomy bag, excluding it from the body

  likely to be losing a lot of Na+
• What is the effect of dehydration on blood flow to the GI tract?

  decreased blood flow
• What does vitamin B12 deficiency cause?

  pernicious anaemia
• What is a treatment option for Vit B12 deficiency?

  Vit B12 injections - hydroxocobalamin

  every 3 months
• What are the potential nutrition and hydration concerns related to a ‘high output’ stoma?

  Dehydration, Na+ levels, nutrient absorption

  shouldn't have fibre / cellulose in diet as colon is removed

  As fibre increases transit time and hence output from high output stoma

  Add more salt to diet
• What is a polymorphism?

  the inability to utilising and accessing certain nutrients / substances, eg vitamin D
• What is ascites?

  fluid in abdomen

  
• What are the symptoms of ascites?

  Tiredness / lethargy due to fluid loss into abdominal cavity

  affects absorption of nutrients
• What is the treatment of ascites?

  Paracentesis (drainage of fluid)

  done very slowly to avoid pushing patient into hypovolemic shock

  
• What would be the nutritional concerns for someone with ascites?

  underweight - may weigh heavy due to fluid accumulation

  but will be underweight and malnourished
• How do we identify underweight / malnourishment in ascites?

  • look for muscle wasting
  • around face / legs: distended huge abdomen with skinny legs & shoulders
  • BMI may be inaccurate
• Why is it difficult to measure accurate BMI on someone with ascites?

  fluid will weigh as well
• What would be the nutritional concerns regarding a patient with ascites, liver disease, low BMI & malnourishment?

  thiamine deficiency

  access to food / rehab

  Can he access food? Does he want to access food?