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Flashcards in Metabolic response to trauma/ critical illness Deck (67):
1

What are the various factors that can contribute to hyper-metabolic response

1) Sepsis
2)Fractures
3)Stress
4)Trauma
5)Burns
6)Major surgery

2

What are hormonal mediators of stress response?

1)Aldosterone
2)Anti-diuretic Hormone (ADH)
3)ACTH
4)Catecholamines

3

What is the role of aldosterone?

Causes renal retention

4

What is the role of ADH?

stimulates renal tubular water absorption

5

What is the role of ACTH?

Acts on aderenal cortex to release cortisol (glucocorticoids). (stimulates lipolysis and mobilized amino acids from skeletal muscles)

6

What hormones are the flow phase characterized by?

High levels of insulin predominant

7

Patients with type I diabetes may have episodes of _____ following an illness or injury

Ketoacidosis

8

What are the metabolic changes following a wound or trauma?

-Phagocytic release of mediators
-Rapid loss of fluid and electrolytes
-Hemorrhage

9

,Regarding metabolic changes following trauma rapid loss of fluid and electrolytes and hemorrhages lead to what?

Hypovolemia

10

Regarding metabolic changes following trauma, hypovolemia leads to what?

Secretion of:
Catecholamines
Aldosterone
ADH
Glucocorticoids

11

Regarding metabolic changes following trauma, release of catecholamines ect. is associated with what?

Increased proteolysis and lipolysis

12

What are the inflammatory mediators of stress response?

Cytokines
Complement
Eicosanoids
PAF

13

What are the general roles of the catecholamines, epinephrine and norepinephrine?

stimulate hepatic glycogenolysis, fat mobilization, gluconeogenesis

14

Where are catecholamines released from?

Adrenal medulla

15

Which cytokines are released by phagocytes in response to tissue damage, infection, inflammation?

Interleukins,
tumor necrosis factor (TNF),
eicosanoids

16

What are the roles of cytokines in response to tissue damage, infection, inflammation?

Promote wound healing,
increase blood supply,
Localize wound
Increase white cell counts and fascilitate migration
Responsible for fever (inc metabolic rate)
Stimulates acute phase protein synthesis

17

What 2 eicosanoids are important mediators of inflammation?

PGE2
PGF2-alpha

18

What is the Ebb phase also known as?

Unresuscitated Phase

19

What is the Flow phase also known as?

Adrenergic - corticoid

20

What is the Anabolic phase also known as?

Recovery/ convalescent phase

21

Nitrogen balance is _______ in the anabolic phase.

Positive

22

What is the nitrogen balance in the Ebb and Flow phase?

Negative

23

What characterizes the Ebb phase?

-Hypovolemia
-Shock
-Tissue hypoxia

24

Why do many patients have lactic acidosis in the Ebb Phase?

-Glucose is oxidized anaerobically to form lactate
-Low blood flow (impaired transport to liver - disrupt Cori cycle)
-May also be seen in flow phase

25

How is the metabolic rate in patients in the Ebb phase?

Decreased

26

How are the insulin levels in the Ebb Phase?

Normal to Low
(Mostly low)

27

Characteristically, how are the insulin levels in the Flow Phase?

High due to insulin resistance

28

How are the cardiac output, body temperature, and energy expenditures in the flow phase?

Increased

29

In the flow phase, there is an increase in circulating levels of what?

Catecholamines
Insulin
Glucagon/cortisol
inflammatory cytokines

30

Total body catabolism begins in what phase post trauma?

Flow phase

31

During the flow phase, catabolized muscle protein provides amino acids for the liver to synthesis of what?

Acute phase proteins

32

What are the acute phase proteins synthesized in the liver in the flow phase?

C-reactive protein
Alpha1-antitrypsin

33

Which amino acids are utilized for maintenance of immune function in the Flow phase?

Glutamine

34

Besides synthesis of acute phase proteins and maintenance of immune function, what else are amino acids used for during the flow phase?

Gluconeogensis precursors
-maintain blood glucose levels

35

Epinephrine and cortisol stimulated increased levels of what during the flow phase?

Lipolysis
- circulating free fatty acids

36

What hormone is characteristic in the flow phase?

Insulin

37

Which hormones contribute to insulin resistance in the flow phase?

Catecholamines
Cortisol
Cytokines

38

Regarding Carbohydrate metbolism, what is predominant in the flow phase?

Glucose productions
Hyperglycemia

39

The metabolic rate is proportional to what in the flow phase?

Extent and severity of injury

40

Why is there hyperglycemia during the ebb phase?

-Epinephrine & Glucorticoids stimulate glycogenolysis and gluconeogenesis
-Low insulin levels

41

What may patients with type I diabetes have episodes of following an injury/infection

Ketoacidosis

42

Why do patients with type I diabetes may have episodes of ketoacidosis following an injury/infection?

Patient does not respond to the normal doses of insulin due to the occurrence of insulin resistance

43

What is the definition of insulin resistance?

Any requirement of insulin during critical illness is greater than 200 Units/day

44

During the flow phase, what is the wound & hypoxic tissues convert most of the glucose to?

Lactacte (anaerobic glycolysis)

45

Once lactate is made in anaerobic glycolysis in the flow phase, where does it go?

Liver - Cori cycle

46

What are he energy providers for the brain in both flow phase and prolonged starvation?

Flow Phase: Glucose
Starvation: Glucose + Ketone bodies

47

Compare GLUT 4 activity in the flow phase and starvation.

Flow: low due to insulin resistance
Starvation: Low due to low levels of insulin

48

Why do patients with major trauma rapidly deplete their fat sotres?

Epinephrine/norepinephrine, glucocorticoids activate Hormone-Sensitive lipase causing high rate of TAG mobilization and oxidation.

49

Why is ketogenesis not observed in patients with major trauma?

-High insulin levels
-Peripheral tissues use free fatty acids or ketone bodies rapidly

50

Ketogenesis is __________ to severity of injury

inversely proportional

51

Protein catabolism is ______ to severity of illness.

proportional

52

Both critical illness and starvation are states of negative nitrogen balance, but protein depletion is_________ in critical illness.

More severe

53

How do you evaluate degree of muscle proteolysis?

Urine Urea Nitrogen (UUN) excretion in gms per day

54

What system in skeletal muscle cells is activated by stress/illness?

Ubiquitin-Proteasome system

55

Proteolysis of skeletal muscle during the flow phase is used for what?

-Hepatic gluconeogensis
-maintenance of immune system

56

Which two amino acids are the major type released during proteolysis after trauma?

Glutamine
Alanine

57

Acute phase proteins are synthesized by the liver in response to inflammation and are commonly used to monitor what?

Progress and prognosis of inflammation.

58

The degree of rise of the acute phase proteins is proportional to?

The severity of injury.

59

Extensive protein depletion after trauma results in what?

-Impaired wound healing
-Decreased immune response
-Breakdown of gut-mucosal barrier
-Decreased mobility/respiratory effort
-Increased predisposition to infection and hypermetabolism (vicious cycle)

60

How much body protein must be depleted for fatality to generally occur?

greater than 20-30%

61

In the anabolic/recovery phase, there is what?

Positive nitrogen balance and build up of tissue protein.

62

During the flow phase, what is characteristic regarding urea excretion in the urine?

Increased

63

What are the goals of nutritional management post trauma?

-Minimalize catabolism
-Meet protein, energy and micronutrient needs
-Establish and maintain fluid and electrolyte balance
-Plan nutrition therapy (oral, enteral, and/or parental nutrition)

64

What is the goal of nutritional support in regards to protein supplementation?

May not result in +N balance, but may slow down protein loss and increase protein synthesis.

65

Which amino acids are supplemented for enhancement of immune function?

Glutamine
Arginine

66

Which nutritional support preserves intestinal mucosal integrity better?

Enteral nutrition
(better than perenteral)

67

What is a prerequisite for enteral nutrition?

Functional GI tract