Pathoma: Other disorders of hemostasis

Question 1

What does HIT stand for?

Answer 1

heparin-induced thrombocytopenia

Question 2

What is heparin-induced thrombocytopenia (HIT)?

Answer 2

platelet destruction post heparin therapy due to antibody formation

Question 3

Why does heparin cause HIT?

Answer 3

Heparin can form complexes with platelet factor 4, and an IgG autoantibody can develop against this, leading to destruction in the spleen

Question 4

What is the major complication of HIT and how does it work?

Answer 4

thrombosis due to platelet fragments activating other platelets

Question 5

What is the treatment of HIT?

Answer 5

stop Heparin and give anticoagulant, but NOT COUMADIN

Question 6

What is DIC?

Answer 6

pathologic (abnormal)activation of the coagulation cascade (as opposed to physiologic)

Question 7

What is the result of DIC?

Answer 7

widespread microthrombi –> ischemia, infarction; also consumption of platelets and factors –> bleeding

Question 8

Where will DIC pts bleed from?

Answer 8

IV sites, mucosal surfaces

Question 9

DIC is almost always 2a to another disease process, such as _____, _____, _____, _____, and _____.

Answer 9

1. obstetric complications
2. sepsis
3. adenocarcinoma
4. APL
5. rattlesnake bite

Question 10

How do obstetric complications lead to DIC?

Answer 10

amniotic fluid contains a lot of tissue thromboplastin (TT), which is a strong activator of the coagulation cascade

Question 11

How does sepsis lead to DIC?

Answer 11

1. bacterial endotoxin can activate coag. cascade

2. cytokines produced by macs can activate coag. cascade

Question 12

How does adenocarcinoma lead to DIC?

Answer 12

mucin produced by the adenocarcinoma can activate coag. cascade

Question 13

How does APL lead to DIC?

Answer 13

Auer rods/primary granules activate coag cascade in circulation

Question 14

How does a rattlesnake bite lead to DIC?

Answer 14

venom in circulation activates the coag cascade

Question 15

What lab findings will be seen in DIC?

Answer 15

1. decreased platelet count
2. increased PT
3. increased PTT
4. decreased fibrinogen
   microangiopathic hemolytic anemia (schistocytes)
5. elevated fibrin split products (D-dimer)*** best test

Question 16

What is the product of lysing cross-linked fibrin?

Answer 16

D-dimer

Question 17

What is the tx for DIC?

Answer 17

address underlying cause, then transfuse or give cryoprecipitate

Question 18

What is fibrinolysis?

Answer 18

the removal of a thrombus

Question 19

What is plasmin?

Answer 19

a molecule that stops clotting and removes clots

Question 20

What does tPA do?

Answer 20

it converts plasminogen into plasmin

Question 21

What does plasmin do?

Answer 21

1. cleaves fibrin
2. cleaves serum fibrinogen and clotting factors
3. blocks platelet aggregation

Question 22

What would overactive plasmin result in?

Answer 22

little to no blood clotting- a disorder of fibrinolysis

Question 23

What is alpha-2-antiplasmin?

Answer 23

molecule that inactivates plasmin

Question 24

How does radical prostatectomy cause overactive plasmin?

Answer 24

the procedure releases urokinase, which activates plasmin

Question 25

How does liver cirrhosis cause overactive plasmin?

Answer 25

causes reduced production of alpha2-antiplasmin, allowing increased plasmin

Question 26

How do the disorders of fibrinolysis present?

Answer 26

resembling DIC

Question 27

What are the lab findings in the disorders of fibrinolysis?

Answer 27

1. increased PT
2. increased PTT
3. increased bleeding me
4. normal platelet count
5. increased fibrinogen split products WITHOUT D-dimer

Question 28

What is the tx for a disorder of fibrinolysis?

Answer 28

aminocaproic acid

Question 29

How does aminocaproic acid work?

Answer 29

it bocks the activation of plasminogen

Question 30

Where is alpha2-antiplasmin produced?

Answer 30

in the liver