Week 3- bleeding disorders Flashcards
What are some causes of vascular abnormalities that could lead to a disorder of primary haemostasis?
Marfans syndrome- collagen is affected so they get excessive bruising, bleeding and floppy heart valves
Vasculitis- inflammation- usually autoantibodies attack vessels making them leaky
Old age- you lose collagen as you grow older.
Steroids- Can lead to thinning of the skin and vessel wall injury by reducing collagen.
Someone suffering from henloch schonlein purpura will have what symptoms?
They will have mucosal and GI bleeds.
What does thrombocytopenia mean?
Low platelets.
Is thrombocytopenia a hereditary or acquired disease?
Hereditary thrombocytopenia Is extremely rare.
Acquired is much more common.
What are the two broad reasons for acquired thrombocytopenia?
Reduced production-bone marrow problem
Increased destruction
What are the causes of peripheral platelet destruction?
Coagulopathy- e.g. DIC
Autoimmune- immune thrombocytopenic purpura (ITP)
Hypersplenism- anything that causes the spleen to be enlarged e.g. portal hypertension.
Describe what occurs in ITP?
Autoantibodies stick to the platelets and cause them to be removed by the reticuloendothelial system.
The bone marrow makes lots and lots of platelets but they are killed, leaving the patient thrombocytopenic.
What can cause functional defects in platelets?
Drugs e.g. aspirin, NSAIDs. Stop the platelets sticking together.
Renal failure- a build up of toxins can interfere with platelet function.
Is VWF deficiency hereditary or acquired?
Hereditary is much more common than acquired.
How is VWF deficiency inherited?
Who does it affect?
Autosomal dominantly.
Affects both men and women equally, however tends to be seen more in women because of heavy periods.
What type of haemostasis does VWF deficiency affect?
Mainly primary however also affects secondary. VWF carries around factor VIII so without it you will also have a factor VIII deficiency.
What symptoms will be seen with VWF deficiency?
Mucosal bleeding
Purpura (bruising)
Menorrhagia in women.
What can failure of the fibrin clot forming be due to?
Single clotting factor deficiency
Or
Multiple clotting factor deficiencies.
What are some causes of single clotting factor deficiencies?
Generally hereditary causes e.g. haemophilia.
What are some causes of multiple clotting factor deficiencies?
These are generally acquired e.g.
DIC
Liver failure- all the clotting factors are produced here so without this you can’t make them
Vitamin K deficiency/warfarin therapy- to get the negative charge on the clotting factors to be attracted to the platelets, you need vitamin K.