Summary

Sepsis is an infection-induced inflammatory syndrome that results in a complex network of adaptive and maladaptive alterations in homeostatic mechanisms. Severe sepsis, defined as sepsis associated with acute organ failure, is a serious disease with a mortality rate of 30–50%. The coagulation system, through complex interactions, has an important role in the final outcome of the sepsis-induced inflammatory cascade. A fine and delicate balance that normally exists between anticoagulant mechanisms and the procoagulant response is altered in sepsis. Activated protein C, an endogenous vitamin K-dependent anticoagulant, plays a major role in the down-regulation of the procoagulant arm. It also possesses anti-inflammatory properties. Endothelial damage during sepsis impairs the endothelium-dependent activation of protein C, thus shifting the balance towards thrombosis. This shift may contribute to the development of sepsis-related multi-organ failure. Evidence suggesting that activation of the coagulation system may contribute to sepsis-related morbidity and mortality has led to extensive research attempting to correct the hemostatic defects seen in septic patients. Indeed, a recent randomized controlled trial demonstrated a reduction in overall mortality in patients with severe sepsis treated with APC[1]. In this review we discuss the pathogenesis of the coagulopathy of sepsis, as well as the new therapeutic approaches aimed at correcting the defects in the coagulation system.