Nutrition and refeeding

Question 1

Which patients may need nutritional support?

Answer 1

1. Malnourished patients:
   - BMI <18.5
   - Unintentional weight loss of >10% in last 3-6 months
   - BMI <20 and unintentional weight loss of >5% in last 3-6 months
2. Risk of malnutrition
   - Eaten nothing for last 5 days/expected to eat nothing for 5 days or more
   - Poor absorptive capacity or high nutritional losses
   - High catabolic state

Question 2

Which patients are at risk of refeeding syndrome?

Answer 2

1. One or more of:
   - BMI <16
   - Unintentional weight loss >15% in last 3-6 months
   - No nutritional intake for 10 days
   - Low levels of potassium, phosphate or magnesium
2. Two or more of:
   - BMI <18.5
   - Unintentional weight loss >10% in last 3-6 months
   - No nutrition for >5 days
   - History of alcohol abuse or medications (e.g. insulin, chemo, antacids, diuretics).

Reintroduction of nutritional requirements should be done in consultation with dietician and nutritional team.

• consider reintroducing at 30% of normal energy and protein requirements - build up slowly over 7 days.
• Ensure adequate B vitamin replacement (Pabrinex one daily/oral B vitamins, thiamine and multivitamins) for 10 days.
• Monitor and replace potassium, phosphate and magnesium.

Question 3

What are the basic daily nutritional requirements for an adult?

Answer 3

Energy: 25-35kcal/kg/day
Protein: 0.8-1.5g/kg/day
Nitrogen: 0.13-0.24g/kg/day
Fluid: 30-35ml/kg/day
Electrolytes:
- Na 1mmol/kg/day
- K 1mmol/kg/day
- Cl 1-2mmol/kg/day
- Mg 0.1mmol/kg/day
- Ca 0.1 mmol/kg/day
- PO 0.4 mmol/kg/day 
Vitamins, minerals and micronutrients

Question 4

When should reduced nutritional support be considered?

Answer 4

In:

• Critically ill patients
• Patient without nutrition for 5 days

Energy and protein requirements should be introduced at 50% for first 48hrs and then slowly increased.
Electrolyte, fluids, vitamins and minerals should be met at 100%

Question 5

How can you assess a patient’s nutritional state?

Answer 5

1. Clinical assessment
2. BMI
3. Laboratory studies

Question 6

How can you assess a patient’s nutritional requirements?

Answer 6

1. Indirect calorimetry
2. Equations (Schofield) - become less accurate the more critically unwell
3. Weight-based

Question 7

How can you assess a patient’s nutritional state?

Answer 7

1. Clinical assessment - recent weight loss, severity of illness, GI dysfunction, MUST scoring.
2. Anthropometric assessments - BMI, MUAC.
3. Laboratory markers

Question 8

How can you assess a patient’s nutritional requirements?

Answer 8

1. Indirect calorimetry
2. Nutritional index equations (Schofield, Harris-Benedict) - become less accurate the more critically unwell
3. Weight-based/IBW

Question 9

Is there an increased mortality risk associated with parenteral nutrition?

Answer 9

Parenteral nutrition does not increase mortality at 30 days (CALORIES)
Early parenteral nutrition not found to improve outcome (EPaNIC)

Question 10

What is refeeding syndrome?

Answer 10

A constellation of features resulting from the rapid reinstitution of feeding/carbohydrate in patient’s who have been food/calorie deprived.

The reinstitution of carbohydrate and feed results in a surge in insulin release with a rapid intracellular shift of K, PO4, Mg.

Clinical features include:

• severe muscle weakness
• respiratory failure
• cardiac arrhythmias
• hypotension
• coma

Question 11

What is the respiratory quotient?

Answer 11

RQ = CO2 produced / O2 consumed

carbohydrates = 1.0
Fats = 0.7
Protein = 0.8