| Comparative Coagulation |
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Clinical Topics - DIC and Thrombosis
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Disseminated Intravascular Coagulation (DIC) and Thrombotic Disorders
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| Disseminated intravascular coagulation is a devastating
clinical syndrome triggered by systemic activation of the coagulation
cascade. DIC is always an acquired syndrome; occuring because of a
primary disease. Many common diseases are capable of initiating DIC,
including neoplasia, shock, sepsis, pancreatitis, and hemolytic anemia.
The disease process is dynamic, with early thrombosis progressing
to diffuse bleeding. The clinical signs of DIC are highly variable
and depend on the underlying disease and the balance between thrombosis
and hemorrhage. |
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Thrombosis and thromboembolism develop in association with many conditions
causing blood stasis, vascular endothelial injury, or hypercoagulability
of blood. Pulmonary thromboembolism is common in dogs and has been
reported in association with hyperadrenocorticism, nephrotic syndrome,
neoplasia, and immune-mediated hemolysis. |
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The early diagnosis of DIC or thromboembolism is difficult, yet intervention
early in the disease process is most likely to benefit the patient.
Careful physical examination and laboratory testing are the most effective
means for their identification. |
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Identification of DIC and Thrombotic Disorders |
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| To identify DIC and thrombosis, use the following
tests: |
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DIC panel: (aPTT, PT, fibrinogen, antithrombin, and quantitative D-dimer)
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Fulminant or hemorrhagic DIC is characterized by prolongation of aPTT, PT, low fibrinogen, and high D-dimer. In chronic or thrombotic DIC, coagulation screening tests may be within normal limits, but D-dimer concentration is high.
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Antithrombin is a natural anticoagulant, and is often depleted during thrombus formation in active DIC. Antithrombin loss also accompanies protein-losing nephropathies and enteropathies, leading to a hypercoagulable state and risk for thrombosis in these conditions.
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D-dimer is a breakdown product of cross-linked fibrin. |
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A rise in plasma D-dimer concentration is an indication of fibrin clot (thrombus) formation and secondary clot lysis.
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Plasminogen is the inactive precursor of the fibrinolytic enzyme
plasmin. |
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Plasminogen levels may fall below normal range as systemic clots
and thromboemboli are degraded.
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