Bleeding disorders Flashcards by Jessica Jefferies

What are the 3 causes of bleeding (and any subtypes)?

Vascular disorders

Platelet disorders:

Thrombocytopenia
Defective function

Defective coagulation:

Inherited
Acquired

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What are the 2 different patterns of bleeding?

Vascular and platelet causes - Bleeding into mucous membranes and skin

Coagulation disorders - Bleeding into joints and soft tissues

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What causes vascular bleeding?

Problems with vessel wall

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What are the 2 types of vascular bleeding and name some examples

Inherited:

Hereditary haemorrhagic telangiectasia
Ehlers-Danlos syndrome

Acquired:

Scurvy, steroids, senile

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What condition is this and what type of bleeding is it?

Hereditary haemorrhagic telangiectasia

Also known as Osler-Weber-Rendu

Vascular bleeding - inherited

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What is thrombocytopaenia and what is the reference range?

Low platelets

Thrombocytopenia – plts < 150

Symptoms when plts < 10

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What are disorders of coagulation and are they more often inherited or acquired?

Due to a defect in the coagulation cascade

Inherited causes (rare)

Acquired causes (common)

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What are the symptoms of thrombocytopaenia?

Epistaxis, GI bleeds, menorrhagia, bruising

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What are the inherited and acquired causes of thrombocytopaenia?

Inherited causes (rare)

Acquired csuses (common)

eg: immune thrombocytopaenia (ITP), drug-related, DIC

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What condition is this?

ITP = immune thrombocytopenia

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For immune thrombocytopaenia, when do you treat and what the 4 treatment options?

Treatment options if bleeding or platelets < 20:

1) steroids and/or intravenous immunoglobulins
2) thromboietin agonists e.g., romiplostim
3) immunosuppression e.g., rituximab
4) splenectomy

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In disorders of platelet function, is the platelet count low, normal or high?

Normal

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What are the causes of disorders of platelet function?

Inherited:

Many rare diagnoses e.g., Glanzmann’s thrombasthenia

Acquired:

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

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Draw the coagulation cascade

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What are the 3 main coagulation tests and which pathway do they test?

APTT = activated partial thromboplastin time

Assesses the intrinsic pathway

PT = prothrombin time

Assesses the extrinsic pathway

TT = thrombin time

Assesses terminal common pathway

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Name 3 other coagulation tests which don’t test specific pathways in the coagulation cascade

Fibrinogen level

Clotting factor assays (normal level 100%)

D-dimers = breakdown products of fibrin clot

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What are the 2 types of haemophilia and what is the deficiency?

Haemophilia A – deficiency of factor VIII

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

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What type of genetic inheritance is haemophilia A and B?

Both X-linked conditions affecting males only

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What are the clinical features of haemophilia?

◦Spontaneous bleeding into joints and muscle

◦Unexpected post-operative bleeding

◦Chronic debilitating joint disease

◦Family history in majority of cases

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What clinical features is this and what dieases does it occur in?

Major haematoma

Haemophilia

What clinical feature is this and which disease does it occur in?

Haemarthrosis

What clinical feature does this show and what disease does it occur in?

Chronic joint deformity

Haemophilia

Which family member passes haemophilia to which family member?

Carrier mums have haemophiliac sons

Draw a genetic diagram for a carrier mum and normal father (haemophilia)

What happens when a father with haemophilia has children? Draw a genetic diagram for this

Dads pass gene to carrier daughters

What 3 tests are done to diagnose haemophilia and what do they test?

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

What is the treatment for haemophilia?

What is the genetic inheritence pattern for von Villebrand disease?

Autosomal dominant

What is von Villebrand disease?

vWD = deficiency of vWF and FVIII in plasma von Willebrand factor = large multimeric protein that carries factor VIII in the blood vWF also binds platelets to endothelial collagen

What are the symptoms of von Villebrand disease?

Mucocutaneous bleeds, nosebleeds, menorrhagia

What 6 test results would be abnormal in von Villebrand disease?

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

What is the treatment for von Villebrand disease and how does it work?

Treatment with desmopressin (DDAVP), anti-fibrinolytics and plasma products DDAVP stimulates release of vWF from Weibel-Palade storage bodies from endothelial cells

What are the 3 acquired disorders of coagulation?

Liver disease ◦Deficient synthesis of clotting proteins ◦Impaired platelet function and fibrinolysis Vitamin K deficiency ◦Infants who do not receive vitamin K at birth ◦Malabsorption due to jaundice Disseminated intravascular coagulation (DIC) ◦Release of pro-coagulant material into circulation ◦Results in consumption of clotting factors Causes both bleeding and thrombosis to occur

What does this picture show?

Meningococcal DIC Disseminated intravascular coagulation (DIC)

What tests would be abnormal in disseminated intravascular coagulation (DIC)?

* Prolonged PT, APTT, TT * Low fibrinogen, low platelets * Raised D-dimers or FDPs

What disease is this?

Disseminated intravascular coagulation (DIC)

Name 3 causes of DIC

cancer, sepsis, obstetric disasters

What does iatrogenic mean?

Overdose of anti-coagulant drugs

Name the 3 types of anti-coagulants

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)

What medication caused this?

What is the role of vitamin K in clotting?

Vitamin K is required for gamma-carboxylation of factors II, VII, IX, X

What drug inhibits vitamin K?

Inhibited by warfarin (monitored using the INR)

What are the 3 causes of deficiency of vitamin K?

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

What is the extrinsic pathway?

factors II,V,VII,X, monitored by PT (basis of the INR)

What is the intrinsic pathway?

factors VIII, IX, (also XI and XII) monitored by APTT (APTR = APTT ratio)

What do both intrinsic and extrinsic pathways activate?

Both pathways activate prothrombinase (factors V, X, Ca and phospholipid)

What happens when prothrombin is activated?

}Prothrombin is activated leading to a “thrombin burst”

What does the cleavage of fibrinogen form?

Fibrin and clot formation