Disorders of coagulation

Question 1

Blood clotting disorders definition?

Answer 1

• Defects in the key components of clotting- Coagulation proteins, Platelets and Endothelium

Question 2

What is haemophillia?

Answer 2

• Haemophilia - failure to clot leading to haemorrhage
o Mutations in coagulation factors (haemophilia A and B)
o Platelet disorders (von Willebrand disease)
o Collagen abnormalities (fragile blood vessels and bruising)

Question 3

What is thrombophilia?

Answer 3

• Thrombophilia – excessive clotting leading to thrombosis
o Inherited: mutations in coagulation factors (DVT)
o Acquired: malignancy increases clotting factors e.g. tissue factor, thrombin factor 10 (DVT)

Question 4

What is DIC?

Answer 4

• Disseminated intravascular coagulation (DIC) – whole body clots
o Infection
o Depletion of clotting factors and platelets leads to bleeding
o Coagulation and bleeding happening simultaneously

Question 5

What is von Willebrand disease?

Answer 5

• von Willebrand disease- Inherited defect/deficiency in vWF- without this there is no platelet adhesion, activation and aggregation- increased risk of bleeding

Question 6

What is Haemophillia B and A respectively?

Answer 6

• Haemophilia B (20%)- Mutated FIX (9)

* Haemophilia A (80%)- Mutated FVIII (8)

Question 7

What will a mutation in factor 8a and 9a result in?

Answer 7

Bleeding

Question 8

What is the symptoms of haemophillia?

Answer 8

• Haemophilia- massive haemorrhage, gross swelling from acute hemarthroses of the knee joint

Question 9

What are the symptoms of VWF

Answer 9

• VWF disease- affects mucous membrane, mostly mild but bleeding can vary in severity

Question 10

Describe excessive clotting

Answer 10

Excessive clotting
• Factor V Leiden mutation
o Resistance to APC- inhibition of this anticoagulant pathway
o FVa is not inactivated- it’s not degraded still works
o Increases risk of DVT

Question 11

What is antithrombin deficiency?

Answer 11

• Antithrombin deficiency
o Thrombin, IXa and FXa are not inactivated- these factors aren’t degraded
o Increases risk of DVT

Question 12

What does protein C and S deficiency increase the risk of?

Answer 12

Protein C deficiency/ Protein S deficiency

o Increases risk of DVT

Question 13

What are the causes of DVT?

Answer 13

o Alterations in the constituents of the blood
o Changes in normal blood flow
o Damage to the endothelial layer

Question 14

What are symptoms of DVT?

Answer 14

•	Symptoms- all due to obstruction of venous return
o	Pain & tenderness of veins
o	Limb swelling 
o	Superficial venous distension
o	Increased skin temperature 
o	Skin discoloration

Question 15

What do the symptoms of DVT reflect?

Answer 15

o All reflect obstruction to the venous drainage

o Increased risk of pulmonary embolism

Question 16

If DVT is above the knee what is it more at risk of?

Answer 16

o If DVT is above knee there’s more risk of DVT embolising

Question 17

What makes up virchows triad and leads to thrombosis?

Answer 17

• Vessel wall injury
• Stasis- reduced venous flow
• hypercoagulability

Question 18

What is DIC?

Answer 18

• As in sepsis (body’s response to an infection injures its own tissues and organs)
• Depletion of clotting factors and platelets leads to bleedin

Question 19

What is treatment of these disorders?
Do they need regulation?
What do thrombolytics and fibrinolytics do?

Answer 19

Treatment
• Warfarin needs to be regulated
• Thrombolytics and fibrinolytics degrade clot
•

Question 20

What is VTE, PT, TT, PTT?

Answer 20

VTE = venous thrombosis embolism
• PT = measures deficiency in factors 8,10,5 and fibrinogen
• Common cause of the above deficiency is liver disease, warfarin therapy and DIC
• TT =. Deficiency or abnormality of fibrinogen due to heparin therapy
• PTT = deficiency of 8,9,11,12,10,5, prothrombin and fibrinogen due to Christmas disease and haemophilia

Question 21

What are the complications of treatments?

Answer 21

Complications of these treatments:
o bleeding- like in node and clots in eye- these are minor
o Severe bleeds include intracerebral bleeds, happen in brain, are larger

Question 22

What do anticoagulants prevent?

Question 23

How are VTE managed?