Non-overt disseminated intravascular coagulation: definition and pathophysiological implications

Both blood and its organ of circulation, the microvasculature, are quintessential components of host defense against injury and pathogen invasion. In this role of maintaining or, in the case of injury or infection, restoring homeostasis, the circulatory organ for blood transport relies particularly on its microvascular and reticuloendothelial components. This role will be reviewed in the context of the inflammatory response to noxious stimuli to the organ, the hemostatic response needed to staunch bleeding and preclude exsanguination, and the complex interplay in these required responses for restoring homeostasis. Indicators of inflammatory regulation will first be examined in the context of localized endothelial injury, platelet activation, procoagulant-anticoagulant complex formation and fibrinolytic induction with regards to their sensitivity and specificity for defining the non-overt disseminated intravascular coagulation (DIC) state. Then, strategies for recognizing and measuring dysregulation will be presented. With better understanding of the complex interplay of all the cellular and chemical regulatory elements of the microvasculature, we may be able to define when non-overt DIC is present and, more importantly, when in this transition state, therapeutic intervention is most efficacious.