Bleeding disorders

Question 1

what are causes of bleeding

Answer 1

Vascular disorders
Platelet disorders
Defective coagulation

Question 2

what are types of platelet disorders

Answer 2

Thrombocytopenia

Defective function

Question 3

what are types of defective coagulation

Answer 3

Inherited

Acquired

Question 4

what pattern of bleeding is caused by vascular and platelet disorders

Answer 4

Bleeding into mucous membranes and skin

Question 5

what pattern of bleeding is caused by coagulation disorders

Answer 5

Bleeding into joints and soft tissues

Question 6

what are inherited issues with vessel walls

Answer 6

Hereditary haemorrhagic telangiectasia

Ehlers-Danlos syndrome

Question 7

what are acquired issues with vessel walls

Answer 7

Scurvy, steroids, senile

Question 8

what is Hereditary haemorrhagic telangiectasia

Answer 8

Also known as Osler-Weber-Rendu

haemorrhage spots on tongue lips (mucous membranes?)

Question 9

what is the normal range of platelets

Answer 9

150-400 x 109/L

Question 10

what is the range of platelets to thrombocytopenia

Answer 10

<150

Question 11

what are symptoms when platelets are less than 10

Answer 11

Epistaxis, GI bleeds, menorrhagia, bruising

Question 12

what are other causes of thrombocytopenia

Answer 12

Inherited causes (rare) or Acquired causes (common)
eg: ITP, drug-related, DIC

Question 13

what is ITP

Answer 13

immune thrombocytopenia

Question 14

What are treatment options if bleeding or platelets <20

Answer 14

steroids and/or intravenous immunoglobulins
thromboietin agonists e.g., romiplostim
immunosuppression e.g. rituximab
splenectomy

Question 15

what is a key sign of disorders of platelet function

Answer 15

Platelet count – typically normal

Question 16

what are types of disorders of platelet function

Answer 16

Inherited, many rare diagnoses,
e.g., Glanzmann’s thrombasthenia

Acquired, Drugs – much more common
e.g., Aspirin, NSAIDs

Question 17

what causes disorders of coagulation

Answer 17

Due to a defect in the coagulation cascade

Question 18

what are types of coagulation disorders

Answer 18

Inherited causes (rare)

Acquired causes (common)

Question 19

what clotting factors are TF, Prothrombin, Thrombin, Fibrinogen

Answer 19

TF  III
Prothrombin II
Thrombin IIa
Fibrinogen I
Prothrombinase X,V,Ca2+,PL

Question 20

What are tests of coagulation

Answer 20

APTT
PT
TT

Question 21

What is APTT

Answer 21

activated partial thromboplastin time to assesses the intrinsic pathway

Question 22

What is PT

Answer 22

prothrombin time to assesses the extrinsic pathway

Question 23

what is TT

Answer 23

thrombin time to assesses terminal common pathway

Question 24

what are other tests of coagulation

Answer 24

Fibrinogen level
Clotting factor assays (normal level 100%)
Bleeding time (time to stop bleeding) - no longer done
D-dimers = breakdown products of fibrin clot

Question 25

what are the types of haemophilia

Answer 25

Haemophilia A – deficiency of factor VIII Haemophilia B – deficiency of factor IX (also known as Christmas disease)

Question 26

what are the clinical features of haemophilia

Answer 26

Spontaneous bleeding into joints and muscle Unexpected post-operative bleeding Chronic debilitating joint disease Family history in majority of cases (X linked)

Question 27

how is haemophilia diagnosed

Answer 27

Prolonged APTT tests factors VIII, IX, XI, XII in the intrinsic pathway Normal PT tests factors II, V, VII, X in the extrinsic pathway Low factor VIII or IX levels

Question 28

what is considered low for factor VIII or IX in haemophilia

Answer 28

<1% = severe; 1-5% = moderate; >5% = mild haemophilia

Question 29

what are historic treatments for haemophilia

Answer 29

Historic treatments – fractionated human plasma but risk of HIV and Hepatitis C infection (and risk of vCJD)

Question 30

what are current treatments for haemophilia

Answer 30

Current treatment – infusions of recombinant factor VIII or factor IX to 50-100% of normal Prophylactic treatment has revolutionised management of haemophilia patients

Question 31

what is von willebrand disease

Answer 31

Autosomal dominant vWD = deficiency of vWF and FVIII in plasma Mucocutaneous bleeds, nosebleeds, menorrhagia

Question 32

what is von willebrand factor

Answer 32

large multimeric protein that carries factor VIII in the blood vWF also binds platelets to endothelial collagen

Question 33

what are tests for diagnosing vWD

Answer 33

``` Prolonged APTT Normal PT Low vWF antigen level and/or vWF function Low factor VIII level Prolonged bleeding time Defective platelet function ```

Question 34

how can vWD be treated

Answer 34

Treatment with desmopressin (DDAVP), anti-fibrinolytics and plasma products

Question 35

what does DDVAP do for vWD

Answer 35

DDAVP stimulates release of vWF from Weibel-Palade storage bodies from endothelial cells

Question 36

what are acquired disorders for coagulation

Answer 36

These are non-inherited causes of increased bleeding Liver disease, bit K deficiency, disseminated intravascular coagulation (DIC)

Question 37

How is liver disease an acquired disorder of coagulation

Answer 37

Deficient synthesis of clotting proteins | Impaired platelet function and fibrinolysis

Question 38

How is vit K deficiency an acquired disorder of coagulation

Answer 38

Infants who do not receive vitamin K at birth | Malabsorption due to jaundice

Question 39

How is DIC an acquired disorder of coagulation

Answer 39

Release of pro-coagulant material into circulation Results in consumption of clotting factors Causes both bleeding and thrombosis to occur

Question 40

What are anti coagulant drugs

Answer 40

Heparin – used to treat MIs, PEs, DVTs Warfarin – used to treat PEs, DVTs, AF, prosthetic valves DOACs = direct oral anti-coagulants Direct thombin inhibitors (dabigatran, argatroban) Factor Xa inhibitors (rivaroxaban, apixaban)

Question 41

what causes a vitamin k deficiency

Answer 41

Malabsorption of vitamin K Biliary obstruction (jaundice) Haemorrhagic disease of the newborn (give 1mg at birth)

Question 42

what is vitamin k used for

Answer 42

Vitamin K is required for gamma-carboxylation of factors II, VII, IX, X Inhibited by warfarin (monitored using the INR)

Question 43

what is Haemoarthritis

Answer 43

bleeding in the joints