Liver Disease
Obstructive disease
- decreased absorption Vitamin K as it is fat soluble
- Vit K dependent factors affected
- II, VII, IX & X
- raised INR
Hepatocellular Disease
- impairs synthesis of all coagulation proteins
- bleeding episodes treated with FFP or Cryoprecipitate
Vit K Deficiency
Occurs with impaired intake or malabsorption
- Inflammatory Bowel Disease
- blood contains no functional forms of II, VII, IX & X
- reversed in 1/7 of Vit K administration
Antiphospholipid Syndrome
Phospholipid antibodies
- Broad family of autoantibodies that target phospholipids
- can be either procoagulant or anticoagulant
Lupus anticoagulant antibodies
- procoagulant
- associated with thromboembolic events rather than clinical bleeding
Antiphospholipid syndrome
Need 1 clinical and 1 laboratory for diagnosis
Clinical
- Vascular thrombosis
- Catastrophic antiphospholipid syndrome
- Complications of pregnancy (spontaneous abortions / premature intra-uterine deaths)
Laboratory
- detected on 2 tests 6 weeks apart
- anticardiolipin antibodies
- lupus anticoagulant antibodies
Prevalence
Antiphospholipid antibodies is 1-5% in young adults
SLE : anticardiolipin & lupus anticoagulant – 15-30%
Investigation
All patients with a first thrombotic episode should be screened for anticardiolipin & lupus anticoagulant antibodies
Treatment
Antiphospholipid antibodies
- no thrombosis
- modify 2° risk factors if have antibodies
- aspirin is not protective against thrombosis
Antiphospholipid syndrome
- warfarin 2-2.9 decreases thrombosis rate
Thrombocytopaenia
Definition
Platelet count < 50,000 x 10.6/L
Causes
1. Defective production
- disturbane of bone marrow
- i.e. secondary to medication
2. Excessive destruction
Drug-Induced Thrombocytopaenia
- Quinine, Sulphonamides, Digoxin, Morphine & H2 antagonists
- drug binds to platelets & acts as Hapten
- form antigenic substances
- complement activation and Platelets lysis
HITS
- 2° AB- heparin-platelet complexes formed & cause platelet aggregation
- thrombocytopaenia from thrombosis
- rapidly reversed once heparin ceased
- should monitor platelet count in patients on heparin
Idiopathic Thrombocytopenic Purpura
- relatively common disorder
3. Excessive splenic pooling
4. Massive transfusion
Effects
Spontaneous bleeding if < 20,000
Post-traumatic bleed increased if < 100,000