Bleeding Disorders Flashcards
Vascular abnormality causes of failure of platelet plug (4)
Hereditary e.g. Marfan’s,
acquired e.g. vasculitis - HSP, ageing, vitamin C deficiency
Primary haemostasis bleeding pattern
purpura, petechiae mucosal blood blisters, retinal haemorrhages, mucosal type bleeding, epistaxis, easy bleeding, menorrhagia
Thrombocytopaenia causes
hereditary - rare,
acquired - reduced production e.g. marrow problems, increased peripheral destruction
How does marrow problem causing platelet forming problems usually present on bloods?
pancytopenia with reduced Hb and reduced white cells
Majority of causes of thrombocytopaenia are hereditary. T/F?
False - mostly acquired and mostly increased destruction
Causes of peripheral platelet destruction (3)
Coagulopathy e.g. DIC, when coagulating pathway activated,
autoimmune e.g. immune thrombocytopenia purpura (ITP),
hypersplenism e.g. liver disease
Commonest cause of thrombocytopaenia
ITP - peripheral platelets destructed by immune process
Platelet function defects causes
hereditary (rare),
acquired e.g. drugs - aspirin, NSAIDs, renal failure,
vWF deficiency causes
acquired (rare),
hereditary - generally mild
hereditary vWF is usually autosomal dominant. T/F?
True
Commonest cause of primary haemostatic failure, is primary haemostatic failure usually hereditary or acquired?
thrombocytopaenia,
usually acquired
Failure of fibrin clot formation causes
multiple clotting factor deficiencies,
single clotting factor deficiency
Multiple clotting factor deficiency is usually acquired. Give 3 examples of multiple clotting factor deficiency causes?
liver failure,
vitamin K deficiency/warfarin therapy,
complex coagulopathy e.g. DIC
Single clotting factor deficiency is usually hereditary. What is the most common
Haemophilia A and B i.e. clotting factors 8 and 9
PT and APTT results in multiple factor deficiencies?
both delayed
complex coagulopathy meaning
everything activated and used up in coagulation pathway
Where are all coagulation factors synthesised?
Hepatocytes
What factors need vitamin K for carboxylation?
II, VII, IX and X
Sources of vitamin K (2)
diet (leafy green veg),
intestinal synthesis
Where is vitamin K absorbed and what does it need for absorption
absorbed in upper intestine,
needs bile salts for absorption
Causes of vitamin K deficiency (5)
poor dietary intake, malabsorption e.g. Crohn's, obstructive jaundice, warfarin, haemorrhagic disease of the newborn
Mechanism of action of warfarin
Vitamin K antagonists
What causes haemorrhagic disease of the newborn? How prevented?
dietary intake doesn’t contain it,
bowels aren’t yet making it,
preventing by IM vit K at birth
What is disseminated intravascular coagulation
excess and inappropriate activation of the primary, secondary and fibrinolytic haemostatic system
What forms in DIC leading to end organ failure?
microvascular thrombus formation
DIC can occur where there is excessive tissue damage leading to haemostasis activation. Give 4 examples of causes of DIC
sepsis,
cancer,
trauma e.g. RTA so hypovolaemic shock,
obstetric emergencies e.g. placental abruption,
How does body try to compensate in DIC and what does this cause in the patient?
fibrinolysis so clotting factor consumption to try and break up all the microvascular thrombi but then platelets are consumed,
this causes bruising, purpura and generalised bleeding
What will be raised in bloods in DIC?
FDPs i.e. D-Dimers
Treatment of DIC
treat underlying cause,
replacement therapy including platelets, plasma and fibrinogen
Haemophilia pattern of inheritance? What does this mean?
X-linked so females don’t have it severely
Haemophilia presentation (4)
recurrent haemarthroses (ankles most commonly, knees, elbows, often same joint),
recurrent soft tissue bleeds e.g. bruising in toddlers,
FH testing,
prolonged bleeding after dental extractions/surgery
Haemophilia A
factor VIII deficiency
Haemophilia B
factor IX deficiency
Haemophilia B is 5 times more common than Haemophilia A. T/F?
False - A 5 times more common than B
Haemophilia patients don’t get to get prolonged bleeding from small cuts like paper cuts. T/F?
true
Types of haemophilia and which most common
mild,
moderate,
severe - severe most common
PT and APTT screening tests results in haemophilia
PT normal,
APTT abnormal
Haemophilia and recurrent haemarthroses can damage joints over time. T/F?
True
Treatment for haemophilia
Intravenous clotting factors
Echiymosis - what is it and what does it indicate?
big bruises that are bigger than they should be for injury, indicates problem with coagulation cascade
DIC screen
FBC, APTT, PT, fibrinogen, (especially), D-dimer (especially)
DIC presentation
large bruising, bleeding from venepuncture sites, confusion, fever, petechiae & purpura, ARDs
Why do alcoholics end up with thrombocytopaenia?
toxic to bone marrow and also could have hypersplenism and big liver where platelets can get stuck
