Bleeding Disorders

Question 1

Causes of bleeding

Answer 1

Vascular disorders, platelet disorders (thrombocytopenia, defective function), defective coagulation (inherited, acquired)

Question 2

Pattern of bleeding

Answer 2

Depends on aetiology, Pattern of bleeding with a vascular and platelet cause bleeding into mucous membranes and skin)
Coagulation disorders: bleeding into joints and soft tissues

Question 3

Vascular bleeding

Answer 3

Problems with vessel wall
Inherited: Hereditary haemorrhagic telangiectasia, Ehlers-Danlos syndrome
Acquired from: scurvy, steroids, senile

Question 4

Thrombocytopenia

Answer 4

Low platelet count
under 150-400*10^9/l
Symptoms: Epistaxis, GI bleeds, menorrhagia, bruising - start when platelets less than 10
Acquired from: drug related, immune thrombocytopenia, disseminated intravascular coagulation

Question 5

ITP

Answer 5

immune thrombocytopenia

Treat with steroids or IV immunoglobulins or occasionally splenectomy

Question 6

Disorders of platelet function

Answer 6

Platelet count - normal to low
Acquired from drugs like aspirin or NSAIDs
Inherited: rare diagnoses

Question 7

Coagulation disorders

Answer 7

Due to a defect in coagulation cascade

Usually acquired, inherited is rare

Question 8

Haemophilia

Answer 8

A: deficiency in factor 8
B: deficiency in factor 9v (Christmas disease)
X linked - affects males only

Question 9

Clinical features of haemophilia

Answer 9

Spontaneous bleeding into joints and muscles
Unexpected post-op bleeding
Chronic debilitating joint disease - recurrent bleeds in joints - results in arthritis
Usually is a family history

Question 10

Inheritance of haemophilia

Answer 10

Carrier mums have haemophiliac sons

haemophiliac dads pass gene to daughters

Question 11

Coagulation tests

Answer 11

APTT: Activated partial thromboplastin time - assesses the intrinsic pathway (factors 8, 9, 11, 12)
PT: Prothrombin time (tests factor 2, 5, 7, 10)
TT: Thrombin time
Fibrinogen level
Factor level assay
Bleeding time

Question 12

Diagnosis of haemophilia

Answer 12

Prolonged APTT
Normal PT
Low factor 8 or 9 levels

Question 13

Treatments of haemophilia

Answer 13

Historic: Fractionated human plasma
Current: Infusions of factor 8 or 9, prophylactic treatment

Question 14

Von villebrand disease

Answer 14

Autosomal dominant disease with deficiency of vWF and factor 8 in plasma
vWF: large multimeric protein that carries factor 8 in the blood
vWF also binds platelets to endothelial collagen
Symptoms: mucocutaneous bleeds, nosebleeds, menorrhagia

Question 15

Test for vWD

Answer 15

Prolonged APTT
Normal PT
Low vWF level 
Prolonged bleeding time 
Defective platelet function

Question 16

Treatment for vWD

Answer 16

desmopressin, antifibrinolytics and plasma products

Question 17

Liver disease

Answer 17

Can cause haemophilia
Defects synthesis of clotting proteins
Impaired platelet function and fibrinolysis

Question 18

Disseminated intravascular coagulation (DIC)

Answer 18

Release of pro-coagulation material into circulation
Causes both bleeding and thrombosis to occur
Causes of this: cancer, severe infection, obstetric disasters

Question 19

Meningococcal disseminated intravascular coagulation

Answer 19

Prolonged APTT, PT, TT, low fibrinogen, low platelets, raised D-dimers or raised fibrinogen degradation products (FDP)

Question 20

Latrogenic

Answer 20

Overdose of anticoagulant drugs

Question 21

Heparin

Answer 21

Treats MIs, PEs, DVTs

Question 22

Warfarin

Answer 22

Used to treat PEs, DVTs, atrial fibrillation, prosthetic valves

Question 23

DOACS

Answer 23

Direct novel oral anti-coagulation
Direct thrombin inhibitors: dabigatran, argatroban
Factor 10a inhibitors: rivaroxiban, apixaban

Question 24

Vitamin K deficiency

Answer 24

Required for gamma-carboxylation of factors 2, 7, 9, 10
Inhibited by warfarin
Deficiency of vit k due to malabsorption of Vit k, bilary obstruction (jaundice), haemorrhagic disease of new-borns

Question 25

Monitored by PT

Answer 25

Extrinsic - factors 2, 5,7, 10

Question 26

Monitored by APTT

Answer 26

Intrinsic

Question 27

Extrinsic and Intrinsic

Answer 27

Both pathways result in thrombin burst that produces a blood clot and haemostasis