Coagulation Cascade
This pathway is initiated by tissue factor and monitored by PT.
What is the extrinsic pathway?
This coagulation test monitors Warfarin therapy.
What is PT/INR?
This disease is the most common inherited bleeding disorder.
What is von Willebrand disease?
Hemophilia A is caused by deficiency of this factor.
What is Factor VIII?
This test evaluates platelet plug formation under shear stress.
What is the PFA?
This pathway functions primarily as an amplifier of coagulation after clotting has begun.
What is the intrinsic pathway?
This coagulation test monitors heparin therapy.
What is aPTT?
A platelet count below this value is generally considered thrombocytopenic.
What is 150,000/µL?
Hemophilia B is caused by deficiency of this factor.
What is Factor IX?
This coagulation test measures conversion of fibrinogen to fibrin.
What is thrombin time?
This enzyme converts fibrinogen into fibrin.
What is thrombin?
An isolated prolonged aPTT with normal PT suggests this inherited disorder.
What is Hemophilia?
Petechiae, purpura, epistaxis, and menorrhagia are classic manifestations of disorders involving this phase of hemostasis.
What is primary hemostasis?
This factor deficiency prolongs aPTT but usually does NOT cause bleeding.
What is Factor XII deficiency?
This laboratory marker specifically indicates breakdown of cross-linked fibrin.
What is D-dimer?
A deficiency of this factor will prolong BOTH PT and aPTT because it is part of the common pathway.
What is Factor X?
Both PT and aPTT are prolonged, fibrinogen is low, and D-dimer is elevated. This disorder is likely present.
What is DIC?
This medication irreversibly inhibits cyclooxygenase and decreases thromboxane A2 production.
What is aspirin?
These factors are vitamin K dependent. (There are 4.)
What are II, VII, IX, and X?
This study is used to differentiate factor deficiencies from inhibitors.
What is a mixing study?
This factor stabilizes fibrin by cross-linking strands together.
What is Factor XIII?
A patient has prolonged aPTT that corrects with a mixing study. This suggests this type of problem.
What is a factor deficiency?
A patient has:
The diagnosis is:
What is Bernard-Soulier syndrome?
This factor helps distinguish liver disease from vitamin K deficiency because it is not vitamin K dependent.
What is Factor V?
This is the MOST common preanalytic error that falsely prolongs coagulation tests.
What is a short draw citrate tube?