Coagulation studies
- APTT
- INR
- Fibrinogen
Full blood count
- Platelet count
Also
- Platelet microscopy
- Platelet function tests
Renal function test
- Urea: significant uricaemia impairs the coagulation cascade.
Liver panel
The liver synthesises most clotting factors.
Factor VIII is synthesised in significant amounts by endothelial cells. In coagulopathies as a result liver disease, homeostatic rebalancing occurs; plasma levels of FVIII are increased. Possibly synthesised by the extrahepatic endothelium1.
Other testing
vWF assays
- Factor VIII levels (normal is 50-150%)
- von Willbrand factor antigen (normal is between 50% and 200%)
- von Willebrand activity (normal 50-200%, there are various assays which may or may not be clinically significant)
ABO typing
O group patients have ∼20% to 30% lower plasma vWF:Ag levels.
Mixing studies
If factor inhibitors are present, addition of plasma with normal concentration of factors will not restore normal coagulation times. The mixing fails to correct the abnormality. If mixing studies restore normal PT or aPTT the abnormality is due to factor deficiency.
Footnotes
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Lisman T, Leebeek FWG. Hemostatic Alterations in Liver Disease: A Review on Pathophysiology, Clinical Consequences, and Treatment. Digestive Surgery. 2007 Jul;24(4):250–8. ↩