Bleeding disorders Flashcards
(46 cards)
what is haemophilia
an X linked hereditary disorder in which abnormally prolonged bleeding recurs episodically at oe or a few sites on each occasion
what is Haemophilia A
factor VIII deficiency
what is haemophilia B
factor IX deficiency
describe the features of haemophilia
no abnormality of primary haemostasis
bleeding from medium to large blood vessels
mild moderate and severely affected families depending on factor VIII/IX level
what does prothrombin time screen for
Tissue factor/VIIa
what does APTT screen for
VIII/IXa
what does APTT stand for
activate partial thromboplastin time
what are the clinical features of severe haemophilia
recurrent haemarthroses
recurrent soft tissue bleeds-bruising in toddlers
prolonged bleeding after dental extractions, surgery and invasive procedures
what does heparin do
prevents activation factors 2,9,10,11
warfarin
affects synthesis of factors 2,7,9,10
describe blood test abnormalities in haemophilia
APTT prolonged PT normal
what is thrombophilia
familial or acquired disorders of the haemostatic mechanism which are likely to predispose to thrombosis
potential mechanisms of thrombophilia
increase in coagulation activity
decrease in fibrinolytic activity
decrease in anticoagulant activity
name some of the naturally occurring anticoagulants
Serine protease inhibitors
Protein C and Protein S
name some hereditary thrombophilia
Factor V Leiden Prothrombin 20210 mutation Antithrombin deficiency Protein C deficiency Protein S deficiency
if you have a hereditary thrombophilia how do you treat
depending on the clinical picture-only offer anticoagulation if RECURRENT thrombotic events
why in hereditary throbophilias do you not always anticoagulate
many factors influence the patients risk of thrombosis beyond the genetic predisposition
name an acquired thrombophilia
antiphospholipid antibody syndrome
what carries a greater risk factor for thrombosis acquired or hereditary thrombophilia
acquired thrombophilia
what are the features of antiphospholipid syndrome
recurrent thrombosis-arterial including TIA and venous
recurrent fetal loss
mild thrombocytopenia
in terms of haemostasis what does antiphospholipid syndrome cause
conformational change in B2 glycoprotein which leads to activation of both primary and secondary haemostasis and vessel wall abnromalities
how is antiphospholipid syndrome treated
aspirin and warfarin
what does heparin do
potentiates antithrombin with immediate effect
what are the 2 forms of heparin
unfractioned and LMWH
