malnutrition & disorders

Question 1

What is malnutrition?

Answer 1

-State resulting from lack of uptake or intake of nutrition, leading to altered body composition & body cell mass, leading to diminished physical & mental function & impaired clinical outcome from disease

Question 2

Where do we see highest prevalence of malnutrition?

Answer 2

In youngest and oldest age groups. More in women. High prevalence in oncology and care of elderly, and those with GI illness. Risk >65 years hospital admission, those with long term disease and chronic progressive disease, alcohol abuse.

Question 3

When is greatest weight loss seen and what is problem with malnutrition in acute settings?

Answer 3

Greatest weight loss seen in those underweight already. Malnutrition often unrecognised & undiagnosed in acute settings

Question 4

What are some reasons for malnutrition in hospital?

Answer 4

Disease related anorexia, response to stress (muscle breakdown), paradox of metabolic response to injury can lead to tissue loss, reduced food intake (poor appetite, GI symptoms, inactivity, depression, inflexible hospital symptoms, quality of food, belief medical treatment is priority)

Question 5

What is impact of malnutrition in a hospital setting?

Answer 5

Greater mortality post-op, septic complications, increased hospital stay, pressure sores, re-admission, dependency, decreased wound healing, worse response to treatment, rehabilitation & quality of life.

Question 6

What does screening for malnutrition do? Limitations?

Answer 6

Simple tool to identify risk, not assessment or diagnosis. Limitation - can miss malnourished population (eg. Overhydration for oedema)

Question 7

What is included in an assessment of malnutrition by a dietician?

Answer 7

• Collecting & interpreting info to determine cause and nature of imbalance
  1. anthropometric measurements - scale, BMI (rarely), mid-arm muscle circumference)
  2. CT scan to distinguish types of fat
  3. biochemistry - nutrient availability, deficiencies, trace elements)
  4. history - clinical, dietary, nutrition requirements (RMR-BMR - predictive equations to maintain energy balance), social, physical history

Question 8

After diagnosis what is done for malnutrition?

Answer 8

Diagnose, implement, monitor, evaluate

Question 9

When is nutrition support considered?

Answer 9

1. malnourished - BMI<18.5, unintentional weight loss >10% past 3-6 months, or BMI<20 + unintentional weight loss >5% past 3-6 months
2. at risk of malnutrition - have eaten little/nothing for >5 days or wont for next 5 days or have poor absorptive capacity &/or have high nutrient losses &/or increased nutritional needs due to things like catabolism

Question 10

What is artificial nutrition?

Answer 10

Provision of enteral or parenteral nutrients to treat or prevent malnutrition

Question 11

What are types of artificial nutrition and when do you use each?

Answer 11

1. enteral uses gut. Better than parenteral.
2. parenteral - uses blood, aim to return to enteral and then oral feeding asap. Assess considered: if gastric feeding possible naso-gastric tube (NGT). If not naso-duodenal NDT or naso-jejunal NJT.
   If long term > 3 months = gastrostomy/jejunostomy.

Question 12

What do nutritional needs depend on?

Answer 12

Many factors - renal, low sodium, respiratory, immune, elemental, peptide.

Question 13

When is NGT feeding contraindicated and what do you use instead?

Answer 13

NGT contraindicated in gastric outlet obstruction, use NJT

Question 14

What are complications of enteral feeding?

Answer 14

1. mechanical: misplacement (aspirate pH <5.5. if greater x-ray needed to make sure tube is in stomach), blockage, buried bumper.
2. metabolic - hyperglycaemia, deranged electrolytes
3. GI: aspiration, nasopharyngeal pain, laryngeal ulceration, vomiting, diarrhoea

Question 15

What is parenteral nutrition and when is it used? How is it used?

Answer 15

• Parenteral nutrition is delivery of nutrients, electrolytes and fluids directly by venous blood access via central venous catheter at SVC and right atrium.
• Different CVC for short/long term use.
• Composition ready made or scratch bag with fluid/electrolyte target for the day.
• Done when inadequate or unsafe oral or enteral nutrition intake or non functioning, inaccessible, perforated GI tract

Question 16

What are complications of parenteral nutrition?

Answer 16

1. mechanical: line inserted - pneumothorax, haemothroax, thrombosis, cardiac arrhythmia, catheter occlusion, thrombophlebitis, extraversion
2. metabolic: deranged electrolytes, hyperglycaemia, abnormal liver enzymes oedema, hypertriglyciredaemia
3. catheter related infections

Question 17

What is effect of receiving nutrition support on morality and readmissions?

Answer 17

Decreased mortality and readmissions

Question 18

What is albumin? When is it made? What stimulates production and inhibits production?

Answer 18

Protein made in liver. Stimulated by insulin, cortisol, GH. Inhibited by pro-inflammatory cytokines - IL-6, TNF.

Question 19

Why is albumin not a valid marker of malnutrition in acute hospital setting?

Answer 19

Pro-inflammatory cytokines In inflammation act on liver to stimulate production of some proteins and down-regulate others like albumin.
-Negative acute phase protein albumin decreases due to inflammation so not valid marker of malnutrition.

Question 20

When does re-feeding syndrome happen?

Answer 20

When malnourished/starved people are reintroduced to oral/enteral/parenteral nutrition

Question 21

in re-feeding syndrome, what happens during prolonged fasting ?

Answer 21

• Hormonal/metabolic changes to prevent muscle breakdown.
• Muscle decreases ketone body use, uses fatty acids.
• Brain uses ketones instead of glucose.
• Liver decreases gluconeogenesis to preserve muscle.
• Intracellular ions become depleted but serum concentrations normal because intracellular compartment affected

Question 22

In re-feeding syndrome what happens when food is reintroduced? What can this cause?

Answer 22

• Glycaemia leads to increased insulin which stimulates glycogen, fat & protein synthesis, and stimulates absorption of potassium, magnesium and phosphate into cells depleting serum phosphate, magnesium, potassium.
• Hypokalaemia leads to deranged membrane potential so arrhythmias & cardiac arrest.
• Hyperglycaemia leads to fatty liver, hypercapnoea, respiratory failure.
• Magnesium deficiency leads to cardiac dysfunction & neuromuscular complications.
• Thiamine deficiency (co-enzyme in carb metabolism) (vit B1) leads to wernicke’s encephalopathy (ocular abnormalities, ataxia, confusion, hypothermia), or korsakoff’s syndrome (amnesia).
• Rapid decrease in renal excretion of water and sodium, if fluid repletion to maintain urine output may get fluid overload leading to congestive heart failure, pulmonary oedema, cardiac arrhythmia

Question 23

Who is at risk of refeeding syndrome? High risk? Very high risk of refeeding syndrome?

Answer 23

• At risk: very little/no food intake for >5 days.
• High risk: 1 of following –> BMI <16, unintentional weight loss <15% in 3-6 months, very little/no nutrition >10 days, history of alcohol abuse or drugs (insulin, chemo, antacids, diuretics).
• Really high risk –> BMI <15, negligible intake >15 days.

Question 24

How is risk of refeeding syndrome managed?

Answer 24

• Give no more than 10-20kcal/kg of nutrition (40-50% from carbs), micronutrients from onset of feeding, thiamine from onset of feeding.
• Correct & monitor electrolyte daily.
• Monitor fluid shifts & minimise risk of fluid & sodium overload.

Question 25

In pancreatitis what type of feeding is preferred?

Answer 25

Enteral over parenteral. Eg. Naso-gastric tube NGT

Question 26

What should you prescribe before feeding if at risk of refeeding syndrome?

Answer 26

30 minutes before feeding IV pabrinex (contains thiamine)

Question 27

Duodenal stenosis, what type of feeding should you try?

Answer 27

Naso-jejunal tube NJT feeding distal to stenosis

Question 28

How would you know patient isnt absorbing enteral nutrient? What would you do?

Answer 28

Steatorrhea & diarrhoea. Start parenteral nutrition & reduce NJT feeding to minimal rate

Question 29

What is short bowel syndrome and what can it be due to?

Answer 29

From surgical resection, congenital defect or disease associated loss of absorption. Cant maintain protein energy, fluid electrolyte and micronutrient balance on normal diet.

Question 30

What do you need in each type of short bowel syndrome?

Answer 30

Short bowel syndrome <2 m from duodeno-jejunal flexure.
Critical lengths: <100cm of jejunum = long term IV fluid + electrolytes.
<75cm of jejunum = long term PN, fluid + electrolytes. <50cm of jejunum + colon = long term PN, fluid + electrolytes

Question 31

What are surgical options for short bowel syndrome?

Answer 31

Ileocolic anastamosis. Jejunocolic anastamosis. End-jejunostomy.

Question 32

What is end-jejunostomy?

Answer 32

• This surgery involves removal of the colon, ileum, and some of the jejunum.
• The remaining jejunum is then connected to a surgical opening (stoma) created in the belly.

Question 33

What is stoma output target and what does higher stoma output risk?

Answer 33

Stoma target <1.5L/day.

High stoma output risk of dehydration & electrolyte imbalance.

Question 34

How do you prevent further dehydration & electrolyte imbalance? (high stoma output)

Answer 34

Limit all fluids.
-Restrict hypotonic fluids & certain hypertonic fluids containing sorbitol & glucose. Encourage them to drink 1L of glucose saline solution a day

Question 35

What value of urinary sodium indicates dehydration?

Answer 35

<20mmol/L. early measure.