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Flashcards in Physiologic Response to Surgery Deck (65):
1

Define Stress Response

Hormonal & metabolic changes that are triggered by "stress"

2

Physiological Changes that Occur During the Stress Response

Hormonal
Metabolic
Immunological
Hematological

3

Psychological Changes that Occur During the Stress Response

Fatigue
Malaise
Depression

4

Behavioral Change that Occurs During the Stress Response

Reluctance to move

5

Hormonal Response to Stress

Activation of HPA axis & sympathetic nervous system
Receive input from area of trauma or injury
Normal feedback mechanism fails: system doesn't get shut off

6

Sympathetic Nervous System Response to Stress

Adrenal medulla releases catecholamines
Increased norepinephrine from presynaptic nerve terminals
Leads to tachycardia & HTN

7

Renal Effects due to Activation of the Sympathetic Nervous System

Renin release causes conversion of angiotensin I to II
Aldosterone release leads to Na+ retention

8

Pancreatic Effects due to Activation of the Sympathetic Nervous System

Glucagon release
Decreased release of insulin
Some insulin resistance

9

Hepatic Effects due to Activation of the Sympathetic Nervous System

Glycogenolysis
Increased glucose & lactate concentration
Mobilization of FFA from lipid stores

10

Hormones Released by the Anterior Pituitary in a Stress Response

ACTH
GH
Prolactin

11

What releasing factors are released from the hypothalamus to trigger hormone release from the anterior pituitary?

CRH
GHRF

12

What is the posterior pituitary controlled by?

Hypothalamus: directly

13

Hormones Released from the Posterior Pituitary in a Stress Response

ADH

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Changes in the Anterior Pituitary During a Stress Response

Increased ACTH
Increased GH
Increased prolactin

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Increased ACTH Leads to

Increased release of cortisol & glucocorticoids from the adrenal medulla

16

Increased GH Leads to

Increased blood sugar
Antagonizes insulin
May have positive role in wound healing

17

Why is there increased prolactin in the stress response?

Decreased prolactin inhibiting factor

18

Increases in ADH Leads to

Further increase in ACTH

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Function of Cortisol

Promotion of protein breakdown & gluconeogenesis
Inhibits glucose use & increases blood sugar
Promotes lipolysis further increasing blood glucose
Glucocorticoid anti-inflammatory effects
Mineralocorticoid effects causing fluid retention & potassium loss

20

Function of Insulin

Promotes uptake of glucose into muscle & adipose tissue
Coverts glucose into glycogen & triglycerides
Inhibits protein catabolism & lipolysis

21

Function of Increased Glucagon Release

Promotes hepatic glycogenolysis
Increases gluconeogenesis from amino acids in the liver
Has lypolytic activity

22

Effects of the Stress Response on Thyroid Hormones

Total & Free T3 decrease & return to normal after several days
TSH decrease for 2 hours & then return to normal

23

Carbohydrate Metabolism in a Stress Response

Glucose homeostasis mechanisms are ineffective
Lack of insulin to get sugar into the cells

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Hyperglycemia Leads to

Wound infection
Impaired wound healing

25

Protein Metabolism in a Stress Response

Increased cortisol & cytokine concentration
Weight loss & muscle wasting
Can measure protein loos indirectly by nitrogen excretion in the urine

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Increased Cortisol & Cytokine Concentration Leads to

Catabolism primarily from skeletal muscle
Albumin production reduced & alters extracellular volume

27

Lipid Metabolism in a Stress Response

Lipolysis & ketone production

28

Hormones Involved in Water & Electrolyte Metabolism in a Stress Response

ADH
Renin

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ADH in a Stress Response

Promotes water retention
Concentrates urine

30

Renin in a Stress Response

Stimulates angiotensin II which stimulates aldosterone production
Na+ & water resorption
K+ loss

31

How does IL-6 & other cytokines cause the acute phase response?

Production of acute phase proteins

32

Examples of Acute Phase Proteins

Fibrinogen
CRP
Complement
Alpha-2-macroglobulin
Amyloid A
Ceruloplasmin

33

Effects of IL-6 & Cytokines

Fever
Granulocytosis
Hemostasis
Tissue damage limitation
Promotion of healing

34

What is cytokine production limited by?

Cortisol

35

How does anesthesia affect the stress response?

Opioids
Anesthetic drugs
Regional

36

Opioids & the Stress Response

Suppress hypothalamic & pituitary hormone secretion

37

Disadvantages of Opioids in the Stress Response

Prolong recovery
Increase need for post-op ventilatory support

38

Types of Anesthetic Drugs

Etomidate
Benzodiazepines
Clonidine

39

Effect of Etomidate as an Anesthetic Drug

Suppresses cortisol production

40

Effect of Benzodiazepines as an Anesthetic Drug

May inhibit steroid production at the level of the pituitary

41

Effect of Clonidine as an Anesthetic Drug

Inhibit stress responses mediated by the sympathetic nervous system

42

Regional Anesthesia can Reduce

Glucose, ACTH, cortisol, GH, & epinephrine changes

43

Regional Anesthesia can Provide

Excellent anesthesia
Reduce thromboembolic complications
Improved pulmonary function
Reduced paralytic illeus

44

Other Techniques for Modification of the Stress Response

Surgical technique: open vs. laparoscopic
Nutrition
Hormone therapy: insulin infusions
Maintenance of normothermia

45

Define Dehiscence

Wound rupture along the surgical suture

46

Risk Factors for Dehiscence

Age
Obesity
DM
Smoking
Steroids
Poor knot tying or closure techniques
Excessive tension
Trauma or infection

47

Define Evisceration

Abdominal organ are protruding out of an dehiscence wound

48

Define Cellulitis

Infection of the tissue just below the skin surface

49

Define Gangrene

Necrosis of the tissue occurs due to lack of adequate vascular supply or infections

50

Forms of Gangrene

Wet
Dry
Gas
Other

51

Describe Wet Gangrene

Tissue infected
Swollen
Fetid smell

52

Describe Dry Gangrene

Ischemia without infection

53

Describe Gas Gangrene

Bacterial infection that produces gas in the tissues

54

Other Types of Gangrene

Necrotizing fasciitis

55

Define Abscess

Collection of pus built up within the body tissue

56

Describe an Abscess

Painful
Tender
Fluctuant
Erythematous nodule

57

Define Bacteremia

Presence of bacteria in the blood

58

How can blood enter the bloodstream?

Complications of infections
During surgery
Due to catheters & other foreign bodies entering the arteries or veins

59

Define Septicemia

Bacteremia that often occurs with severe infections
Systemic signs & symptoms with organ failure

60

Define Systemic Inflammatory Response Syndrome (SIRS)

Clinical syndrome identical to sepsis characterized by dysregulation of inflammation caused by an infection or non-infectious etiology

61

Examples of Non-Infectious Etiologies

Autoimmune disorder
Pancreatitis
Vasculitis
Thromboembolism
Burns
Surgery

62

Diagnosis of Systemic Inflammatory Response Syndrome (SIRS)

2+ abnormalities in temperature, heart rate, respiration, or WBCs

63

Pathophysiology of Sepsis/SIRS

Release of pro-inflammatory mediators in response to an infection exceeds the boundaries of the local environment, leading to a more generalized response

64

Coagulation in SIRS

Cytokines IL-1 & TNF-alpha
Results in expression of tissue factor
Tissue factor initiates production of thrombin & promotes coagulation
Microvascular thrombosis occurs

65

Organ Dysfunction Occurs as a Result of

Cellular injury
Microvascular thrombosis
Release of pro-inflammatory & anti-inflammatory mediators