A 45-year-old male with severe sepsis develops widespread petechiae, ecchymoses, and bleeding from venipuncture sites. Laboratory tests show prolonged PT and aPTT, thrombocytopenia, and elevated D-dimer. Which of the following is the primary underlying pathophysiological event in this condition?

Explanation

Disseminated Intravascular Coagulation (DIC) is characterized by widespread systemic activation of coagulation, leading to the formation of microthrombi in small blood vessels. This process consumes platelets and clotting factors, which then leads to a secondary hemorrhagic diathesis due to the inability to form new clots. While fibrinolysis is activated secondarily (leading to elevated D-dimer), the primary event is the uncontrolled coagulation. Autoimmune destruction and bone marrow suppression are not the primary mechanisms of DIC.