During the SARS-CoV-2 (COVID-19) pandemic millions of people were affected worldwide,
some only experiencing minor symptoms whilst some developed acute respiratory distress
syndrome (ARDS) requiring admission to the intensive care unit (ICU). ARDS is a
life-threatening condition with mortality ranging from 35-48 %. Gas exchange can be
severely impaired and, in some cases, conventional mechanical ventilation and adjunct
therapies cannot accomplish adequate oxygenation. Veno-venous extracorporeal membrane
oxygenation (V-V ECMO) is recommended as a rescue-support for refractory hypoxemia in
ARDS also following COVID-19 infection and has been utilised widely. However, optimal
management is difficult with prolonged ECMO duration in ARDS patients with COVID-19 and
reported survival rates vary considerably 34-66

%. Complications include severe bleeding requiring more red cell transfusions and
thrombotic complications, which are common despite increased risk of bleeding. Both
bleeding and thrombosis are associated with increased mortality and balancing the
opposing risks is challenging in daily management. On one hand, patients are routinely
exposed to anticoagulant therapy (e.g. systemic heparin for the ECMO circuit operation),
but on the other hand, patients are commonly exposed to blood product transfusions. The
timing, monitoring, efficacy and safety of both blood product transfusion and
anticoagulant therapy remains poorly understood. The investigators therefore aim to
assess the risk of bleeding and thrombo-embolic complications as well as benefit and harm
of blood product transfusion and anticoagulation therapy in adult ICU patients with
COVID-19 supported with V-V ECMO.

Objectives

1. To assess the incidence, site and risks of bleeding and thrombo-embolic events in
ICU patients with COVID-19 supported with V-V ECMO.

2. To assess the quantity of transfused blood products.

3. To assess the clinical practice of anticoagulant therapy in this cohort.

4. To assess the incidence of transfusions-related serious adverse events.