Hemostasis and Common Bleeding Disorders

Question 1

3 main players in bleeding disorders pathophys

Answer 1

Blood vessel wall
Platelets and vWF
Coagulation factors

Question 2

4 main processes to get a clot

Answer 2

Primary hemostasis
Secondary hemostasis
Termination of clotting
Fibrinolysis

Question 3

Primary hemostasis

Answer 3

Initial response to stop bleeding
Forms the primary platelet plug
vWF can bind to the exposed subendothelium and start to elongate to grab the platelets and activate them

Question 4

Secondary hemostasis

Answer 4

Propagation of the clotting process
Involves interaction of coagulation factors on platelet plug
Activated platelets provide a good surface for the coag factors to be activated
Endpoint is a stable fibrin clot

Question 5

What is the main protein created at the end of the coag cascade?

Answer 5

Thrombin

Question 6

Is a
1. Vessel problem
2. Platelet of vWF problem
3. Coag factor problem
due to primary or secondary hemostasis

Answer 6

1. Primary
2. Primary
3. Secondary

Question 7

What coag factor is attached to vWF?

Answer 7

Factor 8

Question 8

Acquired Senile Purpura

Answer 8

Vessel problem
Age dependent deterioration of the vasculature supporting structure
Bruising on the dorsum of the hands and forearms
Serious bleeding does not occur

Question 9

Von Willebrand Disease

Answer 9

Caused by inherited defects in the concentration, structure or function of vWF
Mostly autosomal dominant with variable penetrance

Question 10

3 types of vWF disease

Answer 10

Type 1: decreased amount of vWF (common). Mucocutaneous bleeding
Type 2: dysfunctional vWF protein (uncommon). Mucocutaneous bleeding
Type 3: no vWF protein. Associated decreased factor 8 because vWF is the carrier (rare). Severe mucocutaneous bleeding, can see joint/muscle bleeding

Question 11

Hemophilia (what 2 types)

Answer 11

Inherited bleeding disorder with a mild, moderate or severe deficiency of a coagulation factor
A: factor 8 deficiency (more common)
B: factor 9 deficiency
X linked recessive so seen more commonly in males

Question 12

3 causes of acquired coagulation factor problems

Answer 12

Liver disease (lack of production)
Anticoagulants (bleeding with overdose, trauma, or procedures)
Vitamin K deficiency (several proteins need vit K as a cofactor)

Question 13

Key questions on a clinical bleeding history

Answer 13

Is the bleeding musculocutaneous, soft-tissue or joint?
One or multiple sites?
Inherited or acquired?
Severity (spontaneous/provoked, treated/not)

Question 14

PTT

Answer 14

Partial thromboplastin time

Assesses intrinsic and common pathway

Question 15

PT

Answer 15

Prothrombin time (INR)
Assesses extrinsic and common pathway

Question 16

How to treat vWF disease

Answer 16

1. Release endogenous stores

Provide exogenous vWF

Question 17

Desmopressin (DDAVP)

Answer 17

Hormone that opens the vesicles that store VWF and factor 8 in the endothelial cells and causes their release
Treatment for vWF disease and hemophilia A