Hematology

Question 0

What is secondary hemostasis?

Answer 0

Formation of the fibrinogen clot I.e. factors

1. Extrinsic
2. Intrinsic

Question 1

what is primary hemostasis?

Answer 1

Platelets binding

1. Adhesion
2. Activation
3. Aggregation

Question 2

What is adhesion of primary hemostasis?

i.e. How do platelets bind to broken down endothelium?

Answer 2

Von wilibrands factor (vWF) on the endothelium binds to glyc Ib on platelets

Question 3

What are two diseases associated with adhesion problems of platelets?

Answer 3

Bernard Soliers dz ( malfunctioning glyc Ib)

Von Wilibrands disease (malfunctioning vWF)

Question 4

In primary hemostasis, once adhesion has occurred how are platelets activated?

Answer 4

They express thromboxane A2 (TXA2) and ADP which in turn activates other platelets.

Two drugs that inhibit activation are aspirin (blocks TXA2) and Plavix (inhibits ADP)

Question 5

In primary hemostasis once platelets are adhesive and activated they need to aggregate. How does this occur?

Answer 5

Platelets bind to each other via glyc IIb/ IIIa, and covered with fibrinogen.

Abciximab inhibits this and it’s malfunctioning in Glanzmans Thrombasthenia

Question 6

In secondary hemostasis what are the three pathways?

Answer 6

Common: 1,5,2,10
Extrinsic: 7
Intrinsic: the rest

Question 7

What’s the name of factor 2

Answer 7

Thrombin

Question 8

What’s the name of factor 1

Answer 8

Fibrinogen

Question 9

Factor 1 (fibrinogen) -> Factor 1a (Fibrin). What breaks down fibrin to D-dimers?

Answer 9

Plasmin. Which is activated from plasminogen by tPA

Question 10

What factors does Coumadin inhibit?

Answer 10

2,7,9,10

Question 11

What drugs inhibit factor 10a?

Answer 11

Apixiban,

Rivaroxiban (xarelto)

Question 12

What drugs inhibit thrombin (Factor 2)?

Answer 12

Dabigatran,
Lepirudin,
Argatroban

Question 13

What is the mechanism of action of heparin?

Answer 13

Binds to Antithrombin III. Which inactivates Thrombin (Factor 2)

Question 14

How do you approach a bleeding patient (non life threatening)?

Answer 14

Is it primary or secondary hemostasis?

Primary: vag bleed, oral bleed, petechiae

Secondary: hematoma, hemarthroses

Question 15

If a patient is bleeding with petechiae, oral bleed or vaginal bleed etc. (primary hemostasis) what lab do you want?

Answer 15

Platelet count

Question 16

A bleeding patient with decreased platelets has thrombocytopenia. What are the three causes of thrombocytopenia?

Answer 16

1. Production: BM, Aplastic anemia, Ca infiltrate, Cirrhosis
2. Consumption: DIC, HIT, TTP, ITP
3. Sequestration: spleen

Question 17

A bleeding patient with vaginal bleeding oral bleed petechiae etc. and a normal platelet count has platelet dysfunction. Name five causes of platelet dysfunction

Answer 17

vWD
NSAIDs
ASA
Clopidogrel
Uremia (100s)

Question 18

A “bleeding” pt comes in with hematoma or hemarthroses (secondary hemostasis). What lab study would you want first?

Answer 18

Mixing study

Question 19

A bleeding patient comes in with hematoma hemarthroses and the mixing study corrects. What type of problem is there?

Answer 19

Factor deficiency:
Vit K def
Coumadin
Cirrhosis
DIC
vWD

Question 20

I’m bleeding patient comes in with hematoma and hemarthroses and the mixing study does not correct. What type of problem is there?

Answer 20

And inhibitor problem:
Hemophilia A/B
Sickle cell

Question 21

Diagnose: A patient comes in with fever, autoimmune hemolytic anemia, thrombocytopenia, renal failure, Neuro symptoms

Answer 21

FATRN= TTP

Question 22

What’s the difference between TTP and DIC?

Answer 22

TTP has decreased platelets and everything else normal in the DIC panel. DIC has everything abnormal in the DIC panel.

Question 23

What’s the treatment for DIC?

Answer 23

Treat the underlying disease and give blood products including: platelets, cryo (fix dec fibrinogen), FFP (fix PT PTT INR), PRBCs (schistocytes)

Question 24

How do you treat TTP

Answer 24

Exchange transfusion. never give blood products

Question 25

Diagnosis: A patient comes in on heparin and starts to clot worse.

Answer 25

HIT

Question 26

How do you treat HIT?

Answer 26

Lepirudin or Argatroban. Bridge to Coumadin

Question 27

Diagnosis: A patient comes in asymptomatic and has extremely low platelets in the single digits

Answer 27

ITP

Question 28

How do you diagnose and treat ITP?

Answer 28

This is a diagnosis of exclusion

Tx: platelets, corticosteroids, IVIG, RhoGAM, splenectomy, Rituximab