Platelets and Extracorporeal Membrane Oxygenation Veno-venous

Inclusion Criteria: * Adults aged ≥ 18 years * No objection to participation in the study, obtained from a relative or trusted person; if no relative is available, inclusion under emergency procedure (pending patient or relative non-opposition) * Patients requiring admission to the general intensive care unit of Hôpital Rangueil for venovenous ECMO * Equipped with an arterial catheter for blood sampling * Ability to undergo the 4 blood draws relevant to the study * Receiving therapeutic anticoagulation with unfractionated heparin * Enrolled in a social security program or equivalent * No measures for Limitation and Withdrawal of Therapy have been implemented Exclusion Criteria: * Minors * Patients under court-appointed guardianship or conservatorship * Pregnant or breastfeeding women * Hematological disease (leukemia, lymphoma) or constitutional thrombocytopenia * Platelet transfusion within 7 days prior to enrollment * Indication for immediate emergency ECMO preventing blood sampling before placement * Post-cardiotomy * Patient on antiplatelet therapy * Severe thrombocytopenia \<50 G/L * Other invasive mechanical support such as Impella®, intra-aortic balloon pump, or Left Ventricular Assist Device (LVAD)