Bleeding Disorders Flashcards
haemophilia A vs B?
A = clotting factor 8 deficiency B = clotting factor 9 deficiency
which haemophilia is more common?
A
how is haemophilia inherited?
X linked recessive (more commonly affects boys born to carrier mothers)
some can be sporadic/new mutations (not inherited) which are usually associated with autoimmune disorders
are carrier mothers affected?
some can have prolonged APTT
how does severe haemophilia present?
frequent spontaneous deep muscular haemotomas and haemorthroses (usually results in joint deformity)
usually present <1 year old
how does mod haemophilia present?
occassional spontaneous bleeds and severe bleeding from injuries
usually presents in first 2 years of life
how does mild haemophilia present?
increased/delayed bleeding only after an injury or surgery
usually presents older than 2 years old
how is haemophilia diagnosed?
clinical features + fam history plasma factor 8 and 9 count prolonged APTT normal PT normal vWF normal bleeding time?
how can carriers be tested for the haemophilia mutation in pregnancy?
antenatal testing - amniocentesis/chorionic villous sampling
non-pharmacological management of haemophilia?
physio
hydrotherapy
education and activity modification
avoid NSAIDs and IM/joint injections
pharmacological management of haemophilia?
factor 8/9 IV infusion synthetic vasopressin (only works in haemophilia A and if mild) fibrinolytic inhibitors (eg tranexamic acid) can be helpful in mild cases but should be avoided in haemarthroses or deep muscular haematomas
vaccinations in haemophilia?
hep B
what is von willebrand disease?
inherited bleeding disorder caused by deficiency in von willebrand factor
what is von willebrand factor needed for?
dual role in primary and secondary haemostasis
- enhances platelet adhesion to areas of endothelial damage
- stabilises factor 8 by binding to it
when does von willebrand disease present?
any time in life
how does von willebrand disease present?
easy bruising
prolonged bleeding following minor trauma
heavy bleeding following surgery
conjunctival bleeding
umbilical stump bleeding
menorrhagia
(more mucosal bleeding symptoms than haemophillia)
blood tests in von willebrand disease?
prolonged bleeding time
mildly prolonged APTT (usually not as prolonged as haemophillia)
normal PT
what is ITP?
immune mediated reduction in platelets
antibodies directed towards glycoproteins IIB/IIIa
how do children with ITP present?
acute thrombocytopenia following infection or vaccination
how does adult ITP differ from child ITP?
tend to be more chronic
doesnt always follow an infection/vaccination
needs treatment (children usually self limiting over 1-2 weeks with monitoring)
more common in females
how do adults present with ITP (if symptomatic)?
petichae
purpura
bleeding (eg epistaxis, blood in urine/stools)
mucosal bleeding (eg from gums, menorrhagia)
catastrophic bleeding is rare (eg intracranial bleed)
how is ITP managed in adults?
first line = oral prednisolone IV immunoglobulin (IVIg) may be used in active bleeding or if an urgent procedure is required as it raised platelet count quicker than steroids immunosuppressants can be used splenectomy can be done if platelets <30 after 3 months steroids but rarely done these days
how is ITP investigated?
low platelet count antiplatelet autoantibodies (usually IgG) bone marrow aspirate shows megakaryocytes (do aspirate before steroids to rule out leukaemia)
what causes ITP in adults?
autoimmune attack on platelets
can be triggered by infection etc or idiopathic
what is TTP?
thrombotic thrombocytopenic purpura
disease where many small blood clots form in the smallest arteries resulting in low platelet count (thrombocytpenia) and haemolytic anaemia
signs and symptoms of TTP?
can cause neurological symptoms (headaches, mental change, confusion, paresis, seizures etc) petichae purpura abnormal heavy bleeding anaemia symptoms can have fever can have renal failure (in 10%)
what causes TTP?
not known
associated with deficiency in vWF cleaving enzyme (so lots of vWF in blood leading to lots of clots etc)
acquired TTP thought to be immune related
how is TTP diagnosed?
clinical evaluation
proven? deficiency in vWF enzyme
how is TTP managed?
plasmapheresis or plasma exchange used to remove antibodies that inhibit vWF enzyme
routinely given steroids to inhibit formation of the antibodies
immunosuppressants can be used
