Disorders of Haemostasis Flashcards
Give examples of minor bleeding symptoms
Easy bruising Gum bleeding Frequent nosebleeds (epistaxis) Bleeding after tooth extraction Post-operative
Give examples of minor bleeding symptoms in women
Menorrhagia
Post-partum bleeding
Family history
What are the elements of a significant bleeding history
Epistaxis not stopped by 10 minutes compression pr requiring medical attention/transfusion
Cutaneous haemorrhage or bruising with no trauma
Prolonged (>15min) bleeding from trivial wounds
Menorrhagia requiring treatment that leads to anaemia
Heavy, prolonged or recurrent bleeding after surgery or dental extraction
Why might abnormal haemostasis occur and give an example of how
Lack of a specific factor
Failure of production or increased consumption/clearance
Defective function of a specific factor
Genetic defect or acquire defect (drugs, synthetic defect, inhibition)
Give examples of disorders of primary haemostasis
- thrombocytopenia
- impaired platelet function
- vessel wall dysfunction
- loss or dysfunction of vWF
What may cause thrombocytopenia
Bone marrow failure: e.g. leukaemia, vitamin B12 deficiency
Increased use: e.g. disseminated intravascular coagulation (DIC)
Increased clearance: e.g. autoimmune thrombocytopenic purpura
Pooling of platelets in an enlarged spleen
What occurs in autoimmune thrombocytopenic purpura
Autoantibodies for platelets, causing their phagocytosis by macrophages
What may cause impaired function of platelets in primary haemostasis
Hereditary disorders of glycoproteins: e.g. Bernard-Soulier syndrome, absence of Gp1b
Drugs: e.g. aspirin, NSAIDS, clopidogrel
What can vessel wall dysfunction in primary haemostatic disorders be due to
Hereditary connective tissue disorders e.g. hereditary haemorrhagic telangiectasia (Ehlers-Danlos syndrome) Scurvy Steroid therapy Vasculitis Aging (senile purpura)
What are the functions of VWF in haemostasis
Binding to collagen and capturing platelets
Stabilising factor VIII (may be low if VWF is low)
Describe Von Willebrand Disease
Hereditary disease of vWF quantity or function
but can be caused by antibodies to vWF
May cause low VIII.
Describe the typical bleeding of primary haemostasis
Immediate Superficial bleeding into skin and mucous membranes e.g. nosebleeds Prolonged bleeding from cuts Epistaxes Gum bleeding Menorrhagia Easy bruising Prolonged bleeding after trauma or surgery
What might be the typical bleeding specific to thrombocytopenia and severe VWD
thrombocytopenia - petechiae
Severe VWD - haemophilia-like bleeding
Give some hereditary causes of secondary haemostatic disorders and state their effect
II (incompatible with life)
XI (more bleeding after trauma)
XII (no - adverse effects)
VIII or IX (haemophilia, see below)
Give some causes of secondary haemostatic disorders
Liver disease, because most factors are made there
Dilution of the blood
Anticoagulants: e.g. warfarin
Increased use: e.g. DIC (like for thrombocytopenia)
