haemostasis aquired disorders Flashcards
aquired vascualr bleeding disorders
- senile purpura
- scurvy (vit C deficiency)
- steroid purpura
senile puprora
- collagen reduces, more likely to bruise
- do not bleed excessively after procedures
causes of thrombocytopenia
failure of platelet production
increased consumption of platelets
hypersplenism
failure of platelet production causes
- vitamin B12 or folate deficiency
- bone marrow infiltration (leukaemia or metastases)
- radiation, cytotoxic therapy
increased consumption of platelet causes
- immune thrombocytopenia (ITP)
- disseminated intravascular coagulation
- HIV infection
immune thrombocytopenai
children usually follows acte infection
adults cause usually unclear
treatments for thrombocytopenia
- steroids
- intravenous immunoglobulin
- splenectomy
- thrombopoietin receptor analogues
disseminated intravascualr coagulation
breakdown of haemosttic balance
- simultaneous bleeding and microvascular thrombosis
causes and treatment of disseminated intravascualr coagulation
sepsis
obsteric
malignancy
- remove underlying cause
- give plasma and platelets if bleeding once cause removed
splenomegaly hypersplenism
more platlets found in the spleen
platelet function abnormalities aquired diseases
- antiplatelet drugs
- renal disease
- liver disease
- DIC
antiplatlet drugs
asprin
clopidogrel
prasugrel
asprin how it works
- inhibits cyclo-oxygenase (platelet enzyme) irreversibly
- act for a lifetime of platelet i.e. 7-10 days
how does clopidogrel work
- blocks ADP receptor (or platelet surface) irreversibly
- acts for a lifetime of platelet i.e. 7-10 days
how does prasugrel work
- blocks ADP receptor irreversibly
- acts for a lifetime of platelet i.e. 7-10 days
- more rapid and consistent inhibition than clopidogrel
renal disease types
1) increased bleeding
- anaemia
- thrombocytopenia in autoimmune renal disease
- uraemia
- treat with DDAVP and or dialysis
2) increased thrombotic risk
- in nephrotic syndrome (Acquired antithrombin deficiency)
what is the liver the site of
synthesis of coagluation facors and fibriongen
what is liver disease associated with
bleeding and prolonged prothrombin time
causes of bleeding with liver disease
1) reduced clotting factors
- due to poor synthesis or vit k deficiency
2) thrombocytopenia due to hypersplenism
3) platelet function defect
4) portal hypertension – bleeding from varices
5) dysfibrinogenemia
6) increased fribrino lysis
what is vit K needed for
synthesis of coagulation factors 2, 7, 9 and 10
what does vit k manifest as
prolonged prothrombin time
drugs which cause acquired bleeding disorders
asprin (platelet fuction affected)
heparin (affect coagulation cascade)
warfarin
steroids
thrombosis types
1) in arterial circulation (eg MI or stroke)
- high pressure system
- platelet rich
- treat with antiplatelet drigs
2) in venous circulation (eg DVT or PE)
- low pressure system
- fibrin rich
- treat with anticoagulant drugs
antiplatlet drugs
1) asrpisin
2) clopidogrel
3) prasugrel
4) ticagrelor
