Anticoags and hemmorhage dissorders

Question 1

What sort of chemical is heparin, where is it produced and what function does it have?

Answer 1

Naturally occuring produced by basophils and mas cells to prevent formation and extension of blood clots
Important to note that heparin does NOT disentregrate clots that have already formed.

Question 2

What is the mechanism of heparin?

Answer 2

Binds and activates antithrombin III inhibiting
Thrombin
Factor 9a
Factor 10a

Question 3

What is warfarin derived from and how does it work?

Answer 3

Warfarin (Coumadin) is a synthetic derivative of coumarin and decreases blood coagulation by interfering with K metabolism.

Helps to stop the formation of clots, the extension of clots, and helps to prevent clots from breaking off.

Question 4

What are the vitamin K-dependent clotting factors?

Answer 4

Vitamin K effects the production of clotting factors 
2
7
9
10
Also: protein C and protein S.

Question 5

What is Dabigataran?

Answer 5

A direct thrombin Inhibitor

Question 6

What are rivaroxaban and apixaban?

Answer 6

These are both direct Factor Xa inhibitors.

In other words these inhibit the common pathway.

Question 7

What is Fonaparinux?

Answer 7

Synthetic pentasaccharide inhibitors of Factor Xa

Question 8

What does activated Protein C do?

Answer 8

Breaks down clotting factors 5a and 8a

Question 9

What does Tissue Factor Pathway Inhibitor do?

Answer 9

Inhibits the extrinsic pathway in the clotting system.

Question 10

What would you administer to reverse the effects of too much coumadin (Warfarin)?

Answer 10

Vitamin K!

Question 11

What is the INR, International normalized ration?

Answer 11

This is the PT of the patient devided by a normalized PT and is used to compensate the differences in tissue factor.

Question 12

How would one test for deficient clotting factor?

Answer 12

Mix the patients plasma with normal plasma and test for PT. The PT should normalize if the patient has a clotting factor deficiency.

Question 13

What factors can increase the partial thromboplastin time? (PTT)

Answer 13

Prolonged by heparin, hemophilia, and antiphospholipid antibody.

Question 14

All clotting factors are taken into consideration when testing for coagulation except for which?

Answer 14

VII
and
13

Question 15

Which test is more specific to a low dosage of Heparin?

Answer 15

PTT

as it will be prolonged.

Question 16

Which test is more specific to a low dose of Warfarin (coumadin)

Answer 16

Pt

as it will be prolonged.

Question 17

Where are the effects of warfarin Necrosis most commonly seen?

Answer 17

Thighs, breasts, and buttocks displaying blue/blackening of the skin with a painful eskar.

Question 18

What causes warfarin necrosis?

Answer 18

The patient has a deficiency in protein C which normally inhibits clotting.

Because of this, the other clotting factors 9 and ten are able to continue and thrombosis of the dermal vessels occur.

Question 19

To help avoid Warfarin necrosis, what is done?

Answer 19

Heparin is given first with an anticoagulant, the patient is then transfered to warfarin later.

Question 20

What causes Heparin-induced Thrombocytopenia?

Answer 20

Rarely seen, caused by Platelet factor 4 from platelets binding heparin and blocking its action promoting coagulation.

Antibodies then bind these platelet/heparin complexes leading to endothelial injury leading to even more platelet activation.

Seen most commonly in unfractionated heparin!

Question 21

What is Bernard-Soulier disease?

Answer 21

Defect of platelet adhesion due to missing glycoprotein Ib

These platelets are really large.

Question 22

What is Glanzmann’s Thrombasthenia?

Answer 22

Defects of platelet aggregation due to missing
glycoprotein IIb (Binds platelet to Von willebrands)
and
glycoprotein IIIa (Binds fibrinogen between platelets)

Question 23

What is Thrombotic Thrombocytopenic Purpura?

Answer 23

Antibodies directed against the von Willebrand factor cleaving protease, ADAMTS-13

Question 24

What is von Willebrands disease?

Answer 24

Deficiency of Von willebrands antigen leading to inability to coagulate with hemmorhages.
Seen with easy bruising, nose bleeds, etc.

Question 25

What causes Hemophilia A?

Answer 25

Factor VIII deficiency

Is x-linked recessive

Question 26

What causes hemophilia B?

Answer 26

Factor IX deficiency, is X-linked recessive

Question 27

What causes hemophilia C?

What is the risk population

Answer 27

Milder form in which there is a Factor XI deficiency
Seen in mostly autosomal recessive with some heterozygotes.

Danger population in Ashkenazic Jewish,

Question 28

What are some possible morbidities seen in Hemophilia?

Answer 28

Deep internal bleeding
Joint damage
Transfusion transmitted infection
Adverse reactions to clotting factor treatment
Intracranial haemorrhaging

Question 29

What are two bodily issues that will lengthen PT time, PTT time, Bleeding time, and Platelet count (lower)?

Answer 29

Liver failure

Disseminated intravascular coagulation (DIV)

Question 30

What is the definition of Disseminated Intravascular Coagulation (DIC)?

Answer 30

Acute, subacute, chronic onset of widespread activation of the coagulation system resulting in tiny fibrin thrombi through the entire body,

This depletes platelets leading to patient bleeding to death.

Question 31

What is thrombocytopenia?

Answer 31

Lack of platelets, frequently seen in DIC.

Question 32

What is Consumptive coagulopathy?

Answer 32

This is seen in diseminated intravascular coagulation in which all of the platelets are used up and the patient is at risk of bleeding.

Question 33

Why are cut RBC seen so typically in Disseminated intravascular coagulation?

Answer 33

Strands of fibrin cut the RBC as they pass through causing small infarctions.

Question 34

How can D-DIMER be a sign of Disseminated Intravascular coagulation?

Answer 34

D-DIMER assay measures plasmin-cleaved insoluble cross-linked fibrin.
Thus it is an INDIRECT measure of plasmin and thrombin activity.

Question 35

What are two biochemical markers for disseminated intravascular coagulation?

Answer 35

Plasmin and thrombin

Tested for by the D-DIMER test.