Pathogenesis

Disseminated intravascular coagulation (DIC) can only occur when a prothrombotic stimulus overwhelms the normal regulation of the coagulation cascade.

DIC is most commonly initiated by a mixture of two insults:

• endothelial damage:
  • normal endothelium accumulates antithrombin and thrombomodulin and prevents thrombosis
  • damage to endothelium exposes collagen and sources of tissue factor which stimulate thrombosis
    
    
• pathological release of tissue factor:
  • sources include massive tissue damage, leukaemic cells, amniotic fluid embolism, cancers

Snake bites are a rare but often catastrophic cause of DIC; some venoms act by directly activating coagulation complexes e.g. prothrombinase and thrombin.