Acquired bleeding disorders Flashcards by Hannah Maclean

Common causes of acquired bleeding disorders?

Antithrombotic drugs

Thrombocytopenia

Liver disease

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Some uncommon causes of acquired bleeding disorders?

Vitamin K deficiency

Severe renal failure

Coagulation inhibitors : acquired Haemophelia

Scurvy

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Cause of thrombocytopenia?

Medications

Infections

Bone marrow disorders

These cause: reduced survival or reduced production

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Thrombocytopenia?

a condition that occurs when the platelet count in your blood is too low

An aunt immune disease

Antibody-induced platelet destruction

May be triggered by medications or infection

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Anticoagulants drugs?

Warfarin

Heparins

Dabigatran - Direct thrombin inhibitor

Direct FXa inhibitors - rivaroxaban, apixaban, edoxaban

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Platelet inhibitors?

Aspirin

Dipyridamole

Clopidogrel/ prasugrel

Ticagrelor

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INR?

A standardised prothrombin time

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Use of warfarin?

Prosthetic heart valve

Arterial thromboembolism

Venous thromboembolsims

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Drawbacks of warfarin?

High indices fo drug interactions

Dietary interaction (dark green veg)

Serious/fatal bleeding in around 1% of users per year

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Target enzyemof warfarin?

Vitamin K epoxied reductive

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Metabolism of warfarin?

Cytochrome p-450 dependent

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What is the bleeding die to warfarin dependent on?

INR

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When to INR due to warfarin before dental procedure?

Under INR=4, go ahead

Over INR=4
No more than 24 values

Up to 73 hours for a stable anti-coagulated pt

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Advise for warfarin and dental surgery?

Check INR

Suture and packing

Consider tranexamic acid mw

Avoid nsaids

Single use antibiotic prophylaxis unlikely to affect inr

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Heparin?

Inhibits thrombin and fXa indirectly

Polysaccharide

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When to use LMWH?

Used in the prophylaxis of venous thrombi’s and tx of arterial and venous thrombi’s

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What to do if pt is on LMWH?

Need to interrupt at least 24 hours pre procedure

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DOACs anti-Xa?

Rivaroxaban

Apixaban

Edoxaban

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DOACs antithrombn?

Dabigatran

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Movement of DOACs

Metabolism in liver

Excretion kidneys

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How to proceed with pt on DOACs with a low bleeding ris procedure?

Treat pt without interruption of anticoagulatin

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How to proceed with pt on DOACs witha. High bleeding risk procedure?

Advise to omit dose of DOAC on morning of procedure.

Possibly omit for linger (48-72 hours) of creatinine clearance diminished

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How does aspirin work?

Arreversible inhbir of platelet clycooxygenase

Reduces platelet aggregability

Impairs primary haemostasis

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How does clopidogrel work?

Blocks platelet ADP receptor (P2Y12 receptor)

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How does dipyridamole work?

Blocks platelet phosphodieterase and adenosine deaminase

Why is aspirin widely used?

Secondary prophylaxis of arterial thrombosis

When is aspirin used with dipyridamole?

Stroke

When is aspirin used with clopidogrel?

After coronary intervention

When is aspirin used with rivaroxaban?

In peripheral area disease and coronary artery disease

How long do the effects of aspirin last?

7 days due to irreversibleacetylation of platelet cyclyoxygenase

How long do the effects of clopidogrel last?

Over 5 days due to irreversible blockade of ADP receptor

Do you interrupt pt medication: within 12 months of placement of. A drug - eluding coroary stent taking clopidogrel?

No, do not interrupt

When do ou to interrupt clopidogrel?

Why may a pt have reduced survival of platelets?

Immune thrombocytopenic purpura [ITP] Drug induced

Why may a pt have reduced platelet production?

After chemo Bone marrow malignancy/ failure Megaloblastic anaemia Drug induced Alcohol excess

Tx for ITP?

Responsive to immunosuppressive therapy/splenectomy

How does liver failure affect clotting?

All clotting factors and fibrinogen are synthesised by hepatocytes and almost all are reduced in plasma in liver failure

Effect of liver disease on spleen?

Enlarged

Why does the spleen engage in liver disease?

Due to portal hypertension - leads to thrombocytopenia

Common manifestation of hyperspleenism?

Thrombocytopenia Caused by liver disease

Coagulopathy?

a condition that affects how your blood clots, resulting in more bleeding during surgery, injury, delivery of a baby and/or menstruation

How does coagulopathy from liver disease result in bleeding?

Reduced clotting factors and thrombocytopenia

How does coagulopathy of liver disease cause thrombosis?

Reduced natural anticoagulants

Why is the management of pre ad post op for coagulopathy of liver disease complex?

Striking balance between preventing bleeding and thrombosis Often avoid replacement of clotting factors unless haemorrhagic

Rare causes of acquired bleeding - acquired Haemophelia What are the signs?

New onset bruising/ subcutaneous leading/ internal haemorrhage

Rare causes of acquired bleeding - acquired Haemophelia Causes of AH?

Isolated prolonged APTT and low levels FVIII Antibody to FVIII

Management of acquired Haemophelia?

Bypassing agent e.g. vovoseven to control bleeding Immunosuppressive with high dose steroid +/- cyclophosphamide Refractory cases may require B cell depletion with rituximab

Rare causes of acquired bleeding - vitamin C deficiency What is vitamin C needed for with regard to bleeding?

A co-factor in collagen synthesis

Rare causes of acquired bleeding - vitamin C deficiency Daily dose?

Requir at least 40 mg daily

Rare causes of acquired bleeding - vitamin C deficiency What demographic need more vit C?

Smokers need more

Rare causes of acquired bleeding - vitamin C deficiency Deficiency causes what?

Scurvy after a few months Normocytic anaemia Bleeding with normal platelet and coagulation Skin and gum changes

High risk groups for scurvy?

Alcohol excess Malignancy

Rare causes of acquired bleeding - myoproliferative neoplasm Arises due to what?

Somatic mutation in haematopoietic stem cell disorder

Types of myeloproliferative neoplasm?

Polycythaemia Essential thrombocythaemia Myelofibrosis - mixed picture

myeloproliferative neoplasm What is essential thrombocythaemia?

Increased platelet count

myeloproliferative neoplasm What is polycythaemia?

Excess red cells leading to high Hb and Hct

Myeloproliferative neoplasm What is Myelofibrosis?

Myelofibrosis is an uncommon type of bone marrow cancer that disrupts your body's normal production of blood cells. Myelofibrosis causes extensive scarring in your bone marrow, leading to severe anemia that can cause weakness and fatigue

What to do if pt has myeloproliferative neoplasm, what should you do?

Discuss with haematology department

Hct?

Percentages RBC in pt blood

What can raised Hb/hct and thrombocytosis paradoxically lead to?

Acquired bleeding phenotype You would think it would do the opposite