HP and acute respiratory distress syndrome: The aim of the current study is to analyze the association of indirect measures of hemolysis—such as plasma levels of haptoglobin and COHb—with intensive care unit (ICU) mortality (primary aim) and other important outcomes (eg, incidence of secondary infections such as ventilator-associated pneumonia [VAP], and pulmonary and systemic vascular resistance—secondary aims) in severe ARDS patients supported with VV-ECMO.