Coagulation activation during extracorporeal membrane oxygenation (ECMO).

Area of Science:

• Coagulation science
• Cardiopulmonary bypass
• Thrombosis research

Background:

• Extracorporeal membrane oxygenation (ECMO) is life-saving but associated with circuit thrombus formation.
• Thrombus formation is driven by thrombin generation, requiring activators and phospholipid surfaces.
• Risks include oxygenator occlusion, hemolysis, and arterial embolism.

Purpose of the Study:

• To identify specific coagulation activators in ECMO patient plasma.
• To determine sources of procoagulant phospholipids during ECMO.
• To assess thrombin generation potential (TGP) in ECMO patients.

Main Methods:

• Collected plasma from 60 ECMO patients (1 day-19 years).
• Evaluated native and stimulated TGP, Factor II levels.
• Quantified procoagulant extracellular vesicles via flow cytometry.

Main Results:

• Native TGP increased during ECMO, normalizing post-therapy.
• Activated Factor XIa was the primary TGP activator (100% of samples).
• Procoagulant extracellular vesicles (platelet, red cell origin) increased 2-7 fold, correlating with TGP.

Conclusions:

• ECMO activates plasma coagulation mainly via the contact system and FXIa.
• Platelet and red cell activation generate circulating procoagulant extracellular vesicles.
• These findings elucidate mechanisms of thrombosis during ECMO.