Nutritional support in trauma

Question 1

When does phase 1 occur? What is it? For how long?

Answer 1

2-6 hours after trauma, shock, for 24-48hrs

Question 2

What does phase 1 involve release of?

Answer 2

Cortisol, catecholamines, cytokines

Question 3

4 things that happen in phase 1

Answer 3

HR and respiratory rate increased, peripheral vasoconstriction, hypovolaemia

Question 4

When does phase 2 happen, what is it called?

Answer 4

2 days after

Catabolic

Question 5

3 things released in phase 2?

Answer 5

Cortisol (stimulated by ACTH)
Catecholamines
Glucagon

Question 6

5 things that happen in phase 2

Answer 6

Increased O2 consumption
Increased metabolic rate
Increased glycolysis
Increased lipolysis
Negative nitrogen balance (muscle broken down to AAs)

Question 7

Phase 3 name and when?

Answer 7

Anabolic, weeks after (or 3-8 days after minor surgery) lasts for a few weeks/months

Question 8

4 things that happen in phase 3

Answer 8

Protein synthesis
Normal nitrogen balance
Fat stores
Muscle strength

Question 9

10 affects of cytokines

Answer 9

chemotaxis
Vasodilation
cell adhesion proteins
catabolic (metabolic effect)
Acute phase proteins
T and B cell activation
Anorexia
Endocrine - stimualtes catabolism (catecholamines, cortisol, glucagon) and inhibits anabolism (GH and insulin decreased)
Fever
Fibroblast production

Question 10

Brain obligate substrate?

Answer 10

Glucose

Question 11

How many mins of circulatory failure can the brain survive?

Answer 11

2 mins

Question 12

What does the CNS switch to metabolising in the absence of glucose?

Answer 12

Ketones

Question 13

What do the kidneys and liver metabolise?

Answer 13

Fatty acids and AAs

Question 14

What does skeletal muscle metabolise?

Answer 14

Fatty acids and glycogen stores

Question 15

If glucose and O2 supply interrupted, what 3 stages of metabolism occur?

Answer 15

1. glycogenolysis (glycogen to glucose) max 24hrs
2. gluconeogenesis (muscle to AAs to glucose and lactate)
3. lipolysis and ketogenesis (free fatty acids to acetyl coA to ketones (acetoacetate and hydroxybutarate)

Question 16

Ketosis causes

Answer 16

Diuresis

Question 17

Aerobic resp 1 mol glucose –> ? mol ATP?

Answer 17

36

Question 18

Anaerobic resp 1 mol glucose –> ? mol ATP?

Answer 18

2

Question 19

In an anaerobic response what happens to pyruvate?

Answer 19

Reduced to lactate

Question 20

What is lactate a marker of?

Answer 20

Low pH

Question 21

Why proteolysis increased in trauma?

Answer 21

AAs needed to create inflammatory modulators and gluconeogenesis

Question 22

What are markers of increased proteolysis?

Answer 22

Increased plasma ammonia, increased N2 loss in urine

Question 23

Will adequate calories prevent muscle breakdown in trauma patients?

Answer 23

No, cytokine secretion stimulates muscle breakdown regardless

Question 24

How might a trauma patient get pneumonia?

Answer 24

Muscle breakdown = respiratory muscle weakness

Question 25

Increased lactate is a marker of?

Answer 25

Tissue hypoxia.

Also prognosis

Question 26

What affect does immobilisation have on loss of substances?

Answer 26

Increases loss e.g. Ca, P, Mg

Question 27

Is parenteral or gut-involved feeding better?

Answer 27

Gut

Question 28

What is primary malnutrition?

Answer 28

Starvation or dietary deficiency of specific nutrients

Question 29

What is secondary nutrition?

Answer 29

Nutrition present in adequate amounts but appetite suppressed/absorption failure/increased demand

Question 30

What is refeeding syndrome?

Answer 30

Sudden change from catabolic to anabolic state, insulin produced which = cellular uptake of K+, P, Mg for glycogen, fat and protein synthesis. Results in serum electrolyte defecits e.g. hypokalaemia –> cardiac arrhythmia