Hemodynamics II

Question 1

What are the three arms of Virchow’s triangle?

Answer 1

1. Hypercoagulable state 2. Endothelial injury 3. Circulatory stasis

Question 2

What is the most common cause of primary hypercoagulable state?

Answer 2

Factor V Leiden

Question 3

What is the pathogenesis of Factor V Leiden?

Answer 3

Factor V cannot be broken down by Protein C - increased probability of thrombosis

Question 4

What is the pathogenesis of antiphospholipid antibody syndrome?

Answer 4

Serum Ab directed against anionic phospholipids – hypercoagulability IN VIVO (but not in vitro)

Question 5

What are Lines of Zahn?

Answer 5

Alternate layers of platelets, fibrin, and RBCs in a thrombus

Question 6

What is Trousseau syndrome?

Answer 6

Tumor can produce thromboplastin and serine proteases that activate factor X

Question 7

What is the most critical factor in tissue damage during infarct development?

Answer 7

Availability of alternative blood flow

Question 8

Where do red infarcts occur?

Answer 8

Venous occlusions, loose tissues, dual circulation, previously congested tissues, re-established blood flow to necrotic area

Question 9

Where do white infarcts usually occur?

Answer 9

Solid organs with limitation of blood flow into areas of ischemic necrosis

Question 10

What is the dominant histologic characteristic of post-infarct healing?

Answer 10

Ischemic coagulative necrosis (brain is liquefactive)

Question 11

What characterizes neurogenic shock?

Answer 11

Loss of vascular tone and peripheral pooling of blood

Question 12

What characterizes anaphylactic shock?

Answer 12

Generalized IgE mediated hypersensitivity response associated with vasodilation and increased vascular permeability

Question 13

What are the five unifying features of shock?

Answer 13

1. Intracellular calcium overload 2. Intracellular hydrogen ion 3. Cellular and interstitial edema 4. Catabolic metabolism 5. Inflammation

Question 14

What are Rosen’s empiric criteria for diagnosis of shock?

Answer 14

1. Ill appearance or decreased LOC 2. HR > 100 3. RR > 22 or PCO2 45. Urine output 20 minute duration

Question 15

What characterizes the nonprogressive stage of shock?

Answer 15

1. Reflex compensation and maintenance of tissue perfusion / BP / cardiac output 2. Tachycardia, peripheral vasoconstriction, renal conservation of fluids

Question 16

What characterizes the progressive stage of stage of shock?

Answer 16

1. Worsening circulatory / metabolic imbalance and acidosis 2. Decreased vasomotor responses - arterioles dilate, microcirculation pooling 3. Confusion and decreased urinary output

Question 17

What characterizes the irreversible stage of shock?

Answer 17

1. Irreversible tissue damage 2. Lysosomal cell leakage 3. Decreased myocardial contraction and renal tubular necrosis

Question 18

What are the characteristics of cardiogenic shock?

Answer 18

1. Decreased cardiac output and tissue hypoxia despite adequate intravascular volume 2. Sympathetic constriction of vessels seen by kidneys as low blood volume and poor flow - RAS axis activated, contributes to further edema

Question 19

What is the timing of cytokine release in septic shock / inflammation?

Answer 19

LPS - TNF - IL-1

Question 20

What are the symptoms of neurogenic shock?

Answer 20

Hypotension (vasodilation, lesion at or above T6), bradycardia (unopposed parasympathetic vagal activity, lesion at or above T4)