Haemostasis and Thrombosis in Practice

Question 1

20month old boy refuses to walk in past 2 days
Right knee slightly swollen
Blood aspirated for knee
What is the most likely diagnosis?

Answer 1

Haemophilia

Question 2

How do you differentiate between haemophilia A and B?

Answer 2

Coagulation screen
Prothrombin time (no change)
APTT (longer)
Factor VIII and IX levels
Platelet count

Question 3

Prothrombin time measures what?

Answer 3

Extrinsic pathway for clotting

Question 4

APTT measures what?

Answer 4

Intrinsic pathway for clotting

Question 5

How is Haemophilia inherited?

Answer 5

X-linked

Question 6

A woman says her father has haemophilia A, what are the chances her child will have it?

Answer 6

1 in 4

Question 7

A man says his father has haemophilia A, he has no symptoms, what are the chances his child will have it?

Answer 7

none

Question 8

What is the optimal treatment for severe haemophilia A?

Answer 8

Recombinant factor VIII

DDAVP and tranexamic acid if mild

Question 9

What are the main complications of recombinant clotting factor concentrates?

Answer 9

BB viruses

Development of inhibitory antibodies to the factor

Question 10

What is the treatment regiment in use of factor VIII in haemophilia A patients?

Answer 10

Factor VIII every 1-2 days

Question 11

Which of the following is not a cause of thrombocytopenia?
A. Acute myeloid leukaemia
B. Vitamin K deficiency
C. Aplastic anaemia
D. ITP

Answer 11

B - vitamin K deficiency

Question 12

ITP causes what?

Answer 12

Normal production of platelets but increased consumption

Question 13

At what platelet count do symptoms of thrombocytopenia present?

Answer 13

<10

Question 14

What is the target platelet count for most surgeries?

Answer 14

~50

Question 15

Which of the following is not associated with ITP and why?
A. HIV infection
B. Vitamin C deficiency
C. SLE
D. Glandular fever

Answer 15

Glandular fever (only one which isn’t associated with autoimmune)

Question 16

How does aspirin work?

Answer 16

Reduction of platelet aggregation via COX-1 inhibition

Question 17

Which of the following does NOT inhibit platelet function?
A. Clopidogrel
B. Dabigatran 
C. Abciximab
D. Ticagrelor

Answer 17

Dabigatran - directly inhibits thrombin

Question 18

Outline the function of Clopidogrel, Prasugrel and Ticagrelor?

Answer 18

Stop ADP/Epinephrine from triggering the release to Arachidonic acid

Question 19

How do oral contraceptives affect risk of thromboembolism?

Answer 19

Progesterone = no increased risk
2nd generation = 5x risk
3rd generation = 8x risk

Question 20

Which of the following increase the risk of VTE?
A. Hypercholesterolaemia 
B. Factor V Leiden
C. Von Willebrand factor deficiency
D. Diabetes Mellitus

Answer 20

Factor V leiden as it is the only coagulation disorder