Haemostasis and Thrombosis Review Flashcards
Primary haemostasis =
Formation of platelet plug
Secondary haemostasis
Formation of fibrin clot
Causes of peripheral platelet destruction
- Coagulopathy
(Disseminated intravascular coagulation) - Autoimmune
(Immune thrombocytopenic purpura (ITP)) - Hypersplenism
Acquired platelet function defects
Drugs - aspirin, clopidogrel, NSAIDs
Renal failure
Uraemia
Multiple clotting factor deficiencies - acquired or inherited ?
Acquired
e.g. DIC
*single factor deficiencies tend to be inherited
Causes of DIC
Sepsis
Obstetric emergencies
Malignancy
Hypovolaemic shock
Disseminated intravascular coagulation - main features
- Excessive and inappropriate activation of the haemostatic system
(Primary, secondary and fibrinolysis) - Microvascular thrombus formation
(end organ failure) - Clotting factor consumption
(Bruising, purpura and generalised bleeding
Signs of shock
Pale, clammy
Tachycardia
Hypotension
Hypoxia
What is the purpose of INR ?
Allows standardisation of reporting of prothrombin time
How is prothrombin complex concentrate administered?
IV
How are platelets formed ?
Megakaryocytes in the bone marrow
Liver disease affects which clotting factors?
Vitamin K clotting factors
(II, VII, IX, X)
Why are varicose veins a risk factor for VTE?
Poor flow
Stasis
More damage to walls
(Virchow’s triad)
Why does B12 deficiency cause jaundice?
B12 deficiency causes premature red cell destruction in the marrow
this results in excess bilirubin production.
What are haematocrit levels?
% blood sample filled with RBC
