Thrombosis Parsa

Question 1

What are the components that contribute to thrombosis?

Answer 1

Subendothelial Collagen
Platelets
Coagulation System

Question 2

What causes subendothelial collagen to be exposed?

Answer 2

Endothelial Injury (intact cells protect against thrombosis/ coagulation etc)

Question 3

Endothelial injury due to hypercholesterolemia or inflammation results in

Answer 3

1. Subendothelial collagen exposure

2. Adhesion and Aggregation of platelets to form platelet plug

Question 4

What are the clinical and labratory assessment for assessment for endthelial injury?

Answer 4

1. Inflammation- C proteins
2. Infection- sepsis
3. Massive tissue destruction- obstetrical complications, CA, trauma, burns

Question 5

What is the von Willebrand factor?

Answer 5

located on collagen for receptors of platelets for adhesion

Question 6

Name of the platelet receptor?

Answer 6

GpIb

Question 7

How is aggregation accomplished?

Answer 7

Through the fibrinogen GpIIb-IIIa receptors on different platelets

Question 8

Clinical assessment of platelets

Answer 8

spontaneous mucosal bleeding

petechaie and eccymoses

Question 9

Laboratory assessment of platelets

Answer 9

platelet count

platelet function studies

Question 10

Types of hypercoagulation

Answer 10

Primary- genetic

Secondary- acquired

Question 11

Initial test for coagulation?

Answer 11

Pt and Ptt

Question 12

Other main test for hypercoagulation if PT/PTT are abnormal

Answer 12

Factor 5

Question 13

Secondary Causes of hypercoagulaion?

Answer 13

Prolonged bedrest/immobilization
MI
Atrial fibrillation
Tissue injury (e.g. trauma, surgery, burn)
Cancer
DIC
Heparin-induced thrombocytopenia
Antiphospholipid antibody syndrome
Others: SCA,smoking, contraceptives, etc.

Question 14

Primary causes of hypercoagulation

Answer 14

Point mutation in Factor V (Factor V Leiden)
In ~60% of patients with repeated DVTs
G20210A mutation → ↑prothrombin levels
Other less common and rare conditions:
↑VIII, IX, IX, or fibrinogen (unknown genetics)
↓antithrombin III, C, S, or fibrinolysis
Homozygous homocysteinuria (enzyme def)
Due to linkage with fibrinogen
Anti-phospholipid antibody syndrome (autoimmune)

Question 15

How does aspirin reduce thrombosis?

Answer 15

by blocking TxA2 synthesis (lives the life of platelets/ 7 days)

Question 16

How does warfarin stop thrombosis

Answer 16

antagonizes vitamin K

Too much warfarin= too much bleeding (give pt. vitamn K or clotting factors)

Question 17

What is heparin’s role in preventing thrombosis?

Answer 17

It works with antithrombonin III and prevents thrombosis 1000 times

Question 18

Downside of heparin?

Answer 18

It can cause antbodies to come and signal IgG to produce an auto immune response leading to aggragation of platelets and cause coagulation of endothelium which can lead to thrombosis

Question 19

What is a complication of heparin therapy?

Answer 19

hemmoragic necrosis

Question 20

Which substances promtote formation of plasmin that breaks down the fibrin and dissolves the blood clot or thrombus.

Answer 20

streptokinase and urokinase

Question 21

Fragmented blood cells trying to get by called?

Answer 21

schistocytes (helmet cells)

Question 22

What leads to DIC?

Answer 22

consumes clotting factors by producing microthrombi
(injury, tissue destruction, sepsis)
microthrombi get stuck in capillaries

Plasminogen also acting
Plugging and bleeding at same time
Pt. has low plateles but no being submitted because of plasminogen (d dimer test elevated)