Bleeding disorders Flashcards
What is the platelet count of someone with thrombocytopenia?
<150x10^9/L
What is the platelet count of someone who would be treated for thrombocytopenia?
<50x10^9/L
What are the main causes of thrombocytopenia?
- Failure of marrow production
- Shortened lifespan
- Dilution
- Sequestration
What is sequestration?
Pooling of platelets in spleen
What is the mechanism for acute idiopathic thrombocytopenic purpura?
- Sudden onset after trivial illness
- Platelet will attach viral antigens to itself
What is the mechanism for chronic idiopathic thrombocytopenic purpura?
- Gradual onset
- Autoantibodies against platelet membranes
- Platelets destroyed in spleen hours after being ,made
How is acute idiopathic thrombocytopenic purpura treated?
No treatment, Patient is just observed
How is chronic idiopathic thrombocytopenic purpura treated?
- Corticosteroids
- Splenectomy
- Stem cell transplant
What causes thrombotic thrombocytopenic purpura?
Formation of von willebrand factor multimers which lead to thrombosis
How do you diagnose thrombotic thrombocytopenic purpura?
Look out for:
- Thrombocytopenia
- Schistocytis (fragmented rbcs)
How is thrombotic thrombocytopenic purpura treated?
- Plasma exchange to remove the VWF multimers
What is disseminated intravascular coagulation?
- Widespread innapropriate intravascular deposition of fibrin
- Consumption of coagulation factors and platelets
What does disseminated intravascular coagulation result in?
Thrombocytopenia and bleeding
What causes disseminated intravascular coagulation?
Typically it’s secondary to other causes:
- Infections
- Malignancy
- Tissue damage
How is disseminated intravascular coagulation treated?
-Depends on whether patient is bleeding (fresh frozen plasma) or thrombotic (heparin)
Give an example of an inhereted platelet disorder
Von willebrand disease
What is Von willebrand disease?
A low volume of vWF factors leading to premature destruction of platelets and clots not forming
What are the signs and symptoms of vWF Disease
Frequent nose bleeds
easy bruising
heavy menstural bleeding
How is vWF diagnosed?
Activated partial thromboplastin time being prolonged
What is the treatment for vWF disease?
Generally no treatment is required
What is Glanzmann’s thrombasthenia?
Inability of platelets to bind to fibrinogen, preventing the formation of the platelet plug
How is Glanzmann’s thrombasthenia diagnosed?
Check to see if platlets will react to any type of antagonist
What is the interaction between asparin and platelets?
Asparin irreversably acelates cyclooxygenase 1 which usually catalayses thromboxane A2
What factor deficiency is Haemophilia A associated with
8
How is Haemophilia A diagnosed?
Activated partial thromboplastin abnormally long time
How is haemophilia A treated?
Prophylactic infusions of factor VIII
What is the prognosis for someone with haemophilia A?
Near normal life expectancy, but they should avoid competitive sports
What factor deficieny is Haemophilia B associated with?
9
