|
Factor V Level
|
Factor VII Level
|
Suspect
|
|
normal
|
decreased
|
vitamin K deficiency; isolated deficiency Factor VII (rare)
|
|
decreased
|
normal (or higher than Factor V)
|
DIC; isolated deficiency Factor V (rare)
|
|
decreased
|
decreased
|
liver dysfunction
|
|
normal
|
normal
|
platelet or vascular defect; Hemophilia A or B; von Willebrand's disease
|
Features of Vitamin K deficiency:
(1) Factors 2, 9 and 10 also decreased
(2) response to vitamin K
Features of DIC (with consumption of coagulation factors):
(1) fibrin degradation products
(2) usually thrombocytopenia
(3) usually reduced fibrinogen (may be masked if previously increased levels)
(4) no response to vitamin K
Features of liver dysfunction (with generalized deficiency of coagulation factors):
(1) abnormal liver function tests
(2) no response to vitamin K administration
Limitation: For optimum benefit of this algorithm, coagulation factor levels need to be readily available. This is unlikely in clinics or small hospitals, whereas platelet counts, fibrin degradation products and liver function tests are more readily available.
