Bleeding disorders Flashcards
Name causes of failure of primary haemostasis
Vascular - inherited or acquired e.g. Henoch Schonlein Purpura
Thrombocytopenia - hereditary or acquired (DIC, immune thrombocytopenic purpura, hypersplensim)
Medications
Renal failure
vWF deficiency
What is inherited vWF deficiency
autosomal dominant condition
common
variable severity but generally mild
what is immune thrombocytopenic purpura
immune destruction of platelets
idiopathic usually
acute form usually presents in children. chronic form in adult women
how is ITP managed
oral steroids
IV immuniglobulin
splenectomy has 60 percent cure rate
typically self limiting in children
what is DIC
disorder of clotting (both platelets and fibrin formation and fibrinolysis)
essentially increased release of procoagulation substances, all clotting factors and platelets get used up resulting in profuse bleeding.
small blood vessels become occluded by fibrin and results in microangiopahthic haemolytic anaemia and ischaemic organ damage
can be acute or chronic with the chronic condition is identical but just slower
causes of DIC
infection (gram negative especially) obstetric complications - pre eclampsia, placental abruption, miscarriage, amniotic emboli malignancy ABO transfusion reaction burns sever liver disease AAA - severely ill patients
what is seen on investigation of DIC
bloods - reduced platelets, increased APTT/PT, reduced fibringoen, raised d dimer
blood film - schistocytes (red cell fragments)
how is DIC treated
platelets and coag factors. platelet transfusions, fresh frozen plasma or cryopreciptate.
treat underlying cause
if chronic form may need anticoagulated
what is the main indicator for crypopreciptate
low fibrinogen
most common reason for failure of primary haemostasis
acquired thrombocytopenia e.g. DIC, ITP, hypersplenism
vWF is most common inherited cause
what causes fibrin clot formation failure
multiple clotting factor deficiences - usually acquired
single clotting factor deficiency - usually hereditary
name multiple factor deficiencies remember ususally acquired
liver failure
vit K deficiency
warfarin
DIC
which clotting factors are dependant on vit K
II, VII, IX, X
what does vit k require to be absobed
bile salts
causes of vit k deficiency
poor dietary intake malabsoption obstructive jaundice vit K haemorrhagic disease of newborn
