disseminated intravascular coagulation
Summary
Disseminated intravascular coagulation (DIC) is a life-threatening coagulopathy characterized by systemic activation of the coagulation cascade, leading to simultaneous thrombosis and hemorrhage. It is always secondary to an underlying condition and presents with bleeding, organ dysfunction, and consumption of clotting factors.
Detail
DIC is a pathologic process involving widespread activation of the coagulation system, resulting in intravascular fibrin formation and platelet aggregation throughout the microvasculature. The process consumes clotting factors (especially fibrinogen, factors V and VIII), platelets, and antithrombin III, leading to a consumptive coagulopathy. Simultaneously, the fibrinolytic system is activated, producing fibrin degradation products (FDPs) that have anticoagulant effects. This creates a paradoxical state where patients experience both thrombotic complications (due to microvascular clots causing organ ischemia) and bleeding complications (due to depletion of clotting factors and platelets). Common triggers include sepsis, trauma, malignancy, obstetric complications, and transfusion reactions. Laboratory findings show prolonged PT/PTT, decreased fibrinogen and platelets, elevated D-dimer and FDPs, and schistocytes on blood smear. Treatment focuses on addressing the underlying cause while providing supportive care with blood products as needed.
Sources
- Robbins and Cotran Pathologic Basis of Disease
- Williams Hematology
- First Aid for the USMLE Step 1
- UpToDate: Disseminated Intravascular Coagulation
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