Factor XIII in the Acute Care Setting and Its Relevance in Obstetric Bleeding.

Background: Major hemorrhage is one of the main causes of preventable mortality in either severe trauma, high-risk surgical patient, or the obstetric population. As underlined by the cell-based coagulation model, a resistant and stable clot is essential to prevent or to stop an ongoing bleeding. Coagulation factor XIII (FXIII) stabilizes the newly formed clot by cross-linking the fibrin monomers into a three-dimensional network and by impeding fibrinolysis. Thus, FXIII is an essential coagulation factor in the acutely bleeding patient. Summary: Acquired FXIII deficiency is much more common than the inherited form. On the basis of acute tissue injury which leads to major bleeding, acquired FXIII deficiency is traditionally considered to be secondary to consumption. However, recent evidence in the field of obstetrics and high-risk surgery suggests that it might be an associated factor rather than a consequence of the bleeding, which would mean that early replacement of FXIII could potentially improve outcomes. However, FXIII measurement is not universally available. Assessing FXIII through viscoelastic assays seems feasible, though likely it is not yet accurate. Moreover, the target population at risk and the aimed FXIII level required to achieve hemostasis in each condition are yet to be defined. Key Messages: FXIII should be assessed and replaced if necessary in the acutely bleeding patient. We recommend FXIII to be included in an escalating scheme of hemostatic therapies in the acute care setting.