Bleeding Disorders

Question 1

Causes of platelet plug formation failure

Answer 1

1. Vascular
2. Platelets - reduced number and function
3. Von Willebrand factor

Question 2

List the vascular abnormalities leading to poor platelet plug formation

Answer 2

hereditary - marfan’s syndrome

Acquired
Vasculitis - inflammation makes it leaky
ex. Henoch-Schonlein purpura

Question 3

Presentation of henoch-schonlein purpura in children

Answer 3

Mucosal bleeding
Fresh PR bleeding
Purpura on lower limbs

Question 4

What are other causes of vascular abnormalities leading to bleeding disorders?

Answer 4

Scurvy

Senile purpura - lower limb (these vessels are more leaky)

Question 5

List the causes of thrombocytopenia

Answer 5

Hereditary - rare

Acquired

Question 6

What are the acquired causes of thrombocytopenia?

Answer 6

Reduced production (marrow problem)

Increased destruction by liver and spleen

Question 7

What are the causes of peripheral platelet destruction

Answer 7

Anything that causes tissue damage activates both 1ry and 2ry haemostasis using up the coagulation cells

Coagulopathy
- Disseminated intravascular coagulation

Autoimmune
- Immune thrombocytopenic purpura (ITP)

Hypersplenism - engorgement of spleen d/t bacflow of portal system

Question 8

List the causes of platelet function defects

Answer 8

Hereditary

Acquired

• Drugs: aspirin, NSAID
• Renal failure: toxins build up and kidneys don’t clear them (uraemia prevents platelet from functioning)

Question 9

List the causes of vWF decifiency

Answer 9

Acquired

Hereditary:

• Autosomol dominant
• Common
• Variable severity: generally mild (low levels lead to significant bleeding problem)

Question 10

WHat is the most common cause of primary haemostatic failure?

Answer 10

Thrombocytopenia

Question 11

What are the causes of haemostatic failure?

Answer 11

Marrow failure
Peripheral destruction (transfusion of platelets in this case is useless)

Question 12

Causes of fibrin clot formation defects

Answer 12

Multiple clotting factor deficiencies

• generally acquired
• ex. DIC

Single clotting factor deficiency

• generally hereditary
• ex. haemophilia (factor VIII/IX)

Question 13

What is the most common cause of multiple clotting factor deficiencies?

Answer 13

Liver disease

Check albumin levels

Question 14

What are other causes of multiple factor deficiencies?

Answer 14

Vitmain K deficiency/warfarin therapy

Complex coagulopathy - DIC

Question 15

Why is warfarin contraindicated in vit K deficient patients?

Answer 15

Warfarin antagonises Vit K and makes it low

Question 16

Which are the Vit K dependent clotting factors?

Answer 16

2, 7, 9 & 10

Question 17

Where are coagulation factors synthesised?

Answer 17

Liver

Reduced in liver failure

Question 18

What are the sources of vit k?

Answer 18

Diet - leafy greens

Intestinal synthesis

Question 19

Where is Vit K absorbed?

Answer 19

Upper intestine

Bile salts required for its absorption

Question 20

What are the causes of vit K

Answer 20

Poor dietary intake
Malabsorption
Obstructive jaundice 
Vit K antagonists (warfarin)
Haemorrhagic disease of the newborn

Question 21

What is DIC?

Answer 21

Excessive and inappropriate activation of haemostatic system

Microvascular thrombus formation (body’s response)- blocks up circulation- further damage to hemostatic system- end organ failure

continuous activation causes consumption of clotting factors

Question 22

What is seen clinically in DIC?

Answer 22

end organ failure
Bruising
Purpura
Generalised bleeding

Question 23

Screening tests for fibrin clot formation

Answer 23

Prothrombin time

APTT

Question 24

Which screening test increases first in liver disease?

Answer 24

Prothrombin time

Question 25

List the causes of DIC

Answer 25

Sepsis Obstetric emergencies - Malignancy - cancer eats through tissue causing bleeding (esp bowel and prostate) Hypovolaemic shock: lacking blood, no oxygenation of blood, tissue factor released, coagulation occurs

Question 26

Treatment of DIC

Answer 26

Treat the underlying cause ``` Replacement therapy: Platelet transfusions Plasma transfusions Fibrinogen replacement (Cryoprecipitate) O2 and fluids for hypovolemic shock ```

Question 27

What is heamophilia?

Answer 27

X - linked, hereditary disorder in which abnormally prolonged bleeding occurs at one or a few sites on each occaision

Question 28

Where does bleeding occur in haemophilia?

Answer 28

Bleeding into the muscles and joints

Question 29

Can women have haemophilia?

Answer 29

Since women have two copies of chromosome X they are carriers (if heterozygous), only men are affected

Question 30

Primary hemostasis is affected in haemophilia- T/f>

Answer 30

FALSE | No abnormality in primary hemostasis

Question 31

What are the types of haemophilia?

Answer 31

Mild Moderate - few spontaneous bleeds Severe -

Question 32

Haemophilia depends on the levels of which clotting factors?

Answer 32

VIII/IX

Question 33

What are the screening tests for fibrin clot formation

Answer 33

Prothrombin time - normal | APTT - increased

Question 34

What are the clinical features of severe Hameophilia?

Answer 34

Recurrent Haemarthroses Recurrent soft tissue bleeds bruising in toddlers Prolonged bleeding after dental extractions, surgery and invasive procedures

Question 35

In which scenario would you see ISOLATED prolonged APTT?

Answer 35

Single factor deficiency (haemophilia)