Haematology: DIC Flashcards
What is disseminated intravascular coagulation?
A disorder characterised by coagulation pathway activation leading to diffusion fibrin deposition in the microvasculature and consumption of coagulation factors and platelets - this can lead to bleeding and organ failure
What can cause it?
Severe sepsis - e.g meningococcal sepsis causing circulatory collapse and shock
Large tissue trauma
Pregnancy complications e.g severe haemorrhage
Malignancy
Blood transfusion reaction
Allergic or toxic reaction e.g to snake venom
What 2 types of DIC are there?
Acute or chronic
What pathway is it likely to be initiated through?
The tissue factor pathway
Regardless of the triggering event of DIC, once initiated is the pathophysiology the same in all causes?
Yes
What are the predominant clinical features?
Bruising
Purpura
Haemorrhage
How is it diagnosed?
Thrombocytopenia
Prolonged PT and APTT
Low fibrinogen
Raised fibrinogen degradation products and D dimers
Microangiopathic haemolytic anaemia usually
Reduction in naturally occurring anticoagulants- protein C, S and antithrombin
How is it managed?
Treat underlying cause Support the various organs - ventilation, transfusions FFP to replace clotting factors Cryoprecipitate Platelets
Why does widespread clotting occur?
Due to the release of a procoagulant - disrupts the normal balance of clot formation and fibrinolysis
Procoagulants: tissue factor or bacterial components
Which organs are particularly susceptible to the ischaemia caused by the widespread clot formation?
Kidneys, liver, lungs, brain
What does the widespread clot formation deplete?
Platelets and clotting factors
Paradox of thrombosis and at the same time bleeding
In what situations can DIC be more of a chronic process?
Solid tumours
Large aortic aneurysms
There may be physiological compensation
