Importance of Monitoring Primary Hemostasis Pathology in Patients on Extracorporeal Membrane Oxygenation (ECMO) During Lung Transplantation

ECMO is a type of extracorporeal circulation that has experienced a significant increase in use in the last decade as a substitute for lung or heart functions in patients, both perioperatively - especially extensive thoracic surgery procedures such as lung transplantation, or in resuscitation care - in life-threatening conditions associated with heart or lung failure. It uses the classical principle of extracorporeal circulation technology to create continuous, non-pulsating blood flow and, at the same time, its extracorporeal oxygenation. In its two basic configurations, it can only be used to provide respiratory support (veno-venous configuration, VV ECMO), or also cardiac support (veno-arterial configuration, VA ECMO).

Due to the fact that ECMO circuit is an artificial system consisting of cannulas, blood pump and oxygenator itself, the blood is exposed to a huge surface that is not covered by endothelium, thus stimulates the activation of proinflammatory and procoagulant systems. This exposure results in a prothrombotic condition that is associated with a high risk of thrombotic complications. At the same time, however, with this continuous activation of the coagulation cascade, platelets and coagulation factors are depleted, this may lead to an increased risk of bleeding. Pathological shear stress may result in direct binding of VWF (von Willebrand factor) and the platelet GPIIb / IIIa receptor, resulting in their activation and thrombotic complications, however, the effect of non-physiological shear stress may also lead to loss of GPIbα and GPVI platelet receptors, which, in the opposite, causes a disorder of their adhesion and aggregation to VWF and collagen and increases risk of bleeding. Another important factor is loss and fragmentation of the large VWF multimers, a condition known as acquired von Willebrand's syndrome, which causes platelet adhesion to be impaired and thus contributes to bleeding complications.

Both of these situations, definitely, increase morbidity and mortality in patients, so it is necessary to find an optimal and reliable options for the coagulation system functions monitoration, based on which it is possible to immediately perform a targeted therapeutic intervention.

Results of several studies suggest, that increased platelet activation or decreased function results in both thrombotic and bleeding complications in patients requiring extracorporeal support, and these changes cannot be detected by tests, which are usually performed (ROTEM or other common coagulation tests).

Hypothesis: