Parenteral Nutrition

Question 1

Parenteral

Answer 1

Nutrition that is placed directly into vascular circulation
Via IV or IO for small patients and neonates
For use when enteral route is not feasible
Can be life sustaining
Don’t put off starting if it is required
Used more frequently in horses than small animals

Question 2

When is enteral nutrition not feasible?

Answer 2

Severe nausea and vomiting
When you cannot protect the airway

Question 3

When is parenteral nutrition used in equine patients?

Answer 3

Equine neonate with sepsis and GIT is unable to cope with feeding
○ Enteral feeding would likely lead to fatal enterocolitis due to ileus
Milk sits in stomach/S.I and causes clostridium to overgrow
Post-operative Colics
○ Ileus and nasogastric reflux
○ Should start sooner to prevent catabolism
○ Poor for restoration of GI function
○ Poor for wound healing

Question 4

Technical requirements for parental nutrition

Answer 4

• 24 hour nursing care
  ○ Continuous rate infusion
• Point-of-care glucose monitoring in early phases
  ○ Regulate as required with insulin infusions
  Don’t reduce parental nutrition
• Other measures are required regularly
  ○ Electrolytes
  ○ BUN
  ○ Albumin
• Formulation of PPN or TPN
• Aseptic vascular access to central vein

Question 5

PPN

Answer 5

Partial parenteral nutrition
Glucose and protein
* more common

Question 6

TPN

Answer 6

Total parenteral nutrition
Glucose, protein and lipids

Question 7

Considerations for vascular access

Answer 7

Use central vein to reduce risk of phlebitis
Multi-lumen catheter - for fluid therapy
STERILE
Solutions will be hyper-osmolar and can irritate peripheral veins
Long-staycatheters, dressed and re-dressed daily

Question 8

Parenteral nutriton formulation

Answer 8

• Maximum use of 1-2 weeks
• Don’t provide complete nutrition
  ○ Provide energy, protein and water-soluble vitamins
  ○ Occasionally need electrolytes and trace elements
• Mix in the correct order and under aseptic conditions to prevent microbial contamination
• Care in patients with Chronic Hepatic Failure, oliguria
• Volume overload

Question 9

Metabolic complications

Answer 9

Hyperglycaemia
Lipaemia
Azotaemia
Hyperammonaemia
Refeeding syndrome

Question 10

What is refeeding syndrome?

Answer 10

○ Hypokalaemia
○ Hypophosphatemia
○ Hypomagnesaemia
Occurs in malnourished patients during artificial refeeding
Due to sudden increase in carbohydrate in food leading to sudden increase in insulin levels

Question 11

Predisposing conditions of Hyperglycaemia

Answer 11

Diabetes mellitus
Hyperadrenocorticism

Question 12

Predisposing conditions of Lipaemia

Answer 12

• Pancreatitis
• Idiopathic hyperlipidaemia
• Diabetes Mellitus
• Hyperadrenocorticism

Question 13

Predisposing conditions of Azotaemia

Answer 13

Renal failure

Question 14

Predisposing conditions of Hyperammonaemia

Answer 14

Hepatic failure
PSS

Question 15

Predisposing conditions of Refeeding syndrome

Answer 15

• Prolonged starvation or catabolic disease
• Diabetes Mellitus

Question 16

Practicalities of parenteral nutrition

Answer 16

• Start with 25-50% RER over first 12-24 hours
  ○ Then increase by 25% every 8 hours up to 100% maximum
• Use a clean giving set EVERY day
• Use fluid pump if possible
• Always wear gloves when handling port
  ○ Risk of infection
• Don’t make more than is required for 24 hours
• Protect the bag from sunlight
  ○ Black tape
  ○ Dark bag
• Stop parenteral nutrition gradually
  ○ Pre-treat with glutamine (1-2g/kg)
  ○ Start enteral food gradually and build-up
  ○ Gradually decrease PN by 25% every 6 to 8hrs

Question 17

What happens if we with-hold food?

Answer 17

• Leads to GI changes
  ○ Villi stunting
  ○ Decreased absorptive capacity
• Predisposes to mild gastric ulceration
• Controversial re-prophylaxis and treatment
  ○ Gastric acid has a purpose - stops commensals entering SI and causing diarrhoea
  Acts as first line of defence
  Diarrhoea in septic foals/human patients
  ○ Glandular ulcers are more likely due to hypoperfusion than acid