Haemostasis- Conditions Flashcards
What is DIC?
Disseminated intravascular coagulation
Excessive and inappropriate activation of the haemostatic system
What causes DIC?
Multiple Clotting Factor Deficiency
- sepsis
- obstetric emergencies
- malignancy
- hypovolaemic shock
Microvascular thrombus formation - end organ failure
Clotting factor consumption - bruising, purpura, generalised bleeding
Presentation of DIC
Acute illness and shock
Ranges from no bleeding to profound haemorrhage
- Bleeding may occur from the mouth, nose and venepuncture sites, and there may be widespread ecchymoses - Thrombotic events - any organ may be involved but the skin, brain and kidneys are most often affected
Investigations for DIC
Bloods-
PT, APTT, TT very prolonged
Fibrinogen levels reduced
High D-dimer (intense fibrinolytic activity)
Thrombocytopenia
Fragmented RBC on film
Management for DIC
Treat underlying cause
Replacement therapy-
Platelets, plasma, fibrinogen
What is haemophilia?
X-linked recessive hereditary disorder
Leads to abnormally prolonged bleeding that episodically recurs
What causes haemophilia?
Single clotting factor deficiency
Depends on type
Haemophilia A -> factor VIII deficiency
Haemophilia B -> factor IX deficiency
A is 5x more common than B
Pathophysiology of haemophilia
Primary haemostasis is normal
Common to bleed from medium and large vessels into joints
Presentation of haemophilia
In mild cases-
Bleeding after injury or surgery
Severe cases-
Recurrent haemarthroses into hinge joints, soft tissue bleeds, toddler bruising, prolonged bleeding after dental extractions, surgeries and other invasive procedures
Investigations for haemophilia
Isolated prolonged aPTT (as this tests for intrinsic pathway function)
Normal PT and TT
Coag factor assays -> factor VIII
How is haemophilia managed?
Factor replacement therapy (A8 B9)
Prophylaxis of clotting factors preventing spontaneous bleeding (common in severe)
Desmopressin stimulates vWF release
Tranexamic acid- anti-fibrinolytics
What is a complication of the replacement infusions?
Autoantibodies may be formed making it ineffective
What is Von WIllerbrand disease
Deficiency of vWF
What causes VW disease?
Autosomal dominant chromosome 12 mutation
What is the pathophysiology behind VWF deficiency ?
VWF plays role in platelet adhesion -> deficiency means defective temporary platelet plug
Also can lead to factor VIII deficiency
