Effects of Blood Pulsatility on Von Willebrand Factor During ECCO2R

A track of major interest to prevent bleeding complications in ECCO2R, and more generally in extracorporeal circulations, is to prevent acquired Willebrand disease. Indeed, a loss of Willebrand factor high molecular weight multimers (Whmwm) is frequently observed in conditions characterized by a continuous blood flow, associated with a high incidence of bleeding. A publication suggested the existence of this phenomenon under ECCO2R achieved through the medical device Hemolung (Alung technology, USA). We preliminary observed an almost constant and early (< 24 hours) decrease in Willebrand factor high molecular weight multimers under ECCO2R. Such a phenomenon is considered as a major factor of hemorrhagic complications. We hypothesize that use of pulsatile extracorporeal blood flow configuration during the full length of ECCO2R therapy, as authorized by the Xenios console (Xenios AG, Heilbronn), would preserve a normal value of Whmwm, mainly by changing the conditions of shear constraints ("shear stress").

Inclusion criteria

• Adult patient hospitalized in the Georges Pompidou European Hospital medical ICU
• Patient with or without SARS-CoV-2 infection
• ECCO2R treatment decision made by the medical team (regardless of the FLOW-ECCO2R protocol): mainly ECCO2R to enable ultraprotective ventilation for Acute respiratory distress syndrome (ARDS) patients or to avoid intubation or to shorten invasive mechanical ventilation in Chronic obstructive pulmonary disease (COPD) patients
• Affiliation to a social security regimen
• Informed consent (patient, trusted person, close family) , by default emergency inclusion notified in medical file and pursuance consent sought
• Negative serum or urinary β-hCG for women of child-bearing potential

Exclusion criteria

• Known allergy to heparin or to any of the excipients of the specialty used
• History of type II heparin-induced thrombopenia
• Thrombocytopenia (platelet < 100.000/mm3)
• Constitutional hemostasis disease interfering with biological assays
• Organic lesion likely to bleed
• Bleeding manifestations or tendencies linked to disorders of hemostasis
• Intracerebral hemorrhage
• Participation in another interventional research involving human participants
• Pregnant or breastfeeding women
• Protected adults (including individual under guardianship by court order)
• Persons deprived of their liberty by judicial or administrative decision