Membrane lung dead space value as a predictor of ECMO failure: a pilot study

Veno-venous ECMO respiratory assistance is a milestone treatment in refractory respiratory failure and may provide sufficient respiratory assistance in patients with deranged lung functions. Despite its crucial role in patient survival, especially in an acute respiratory distress syndrome (ARDS) setting, veno-venous ECMO leads to a systemic inflammatory state resulting in prothrombotic activation that gives rise to the deterioration of the extracorporeal membrane lung itself. This derangement eventually leads to sudden ECMO mechanical failure exposing the patient to severe hypoxemia, which can have fast and dramatic consequences. For these reasons, we measured a number of parameters (such as membrane lung pressure drop and partial oxygen pressure in blood at the outflow tract of the membrane lung) to try to predict the possibility of a sudden ECMO failure. None of these indicators alone seems to have significant power in the clinical setting. Considering membrane lung physiology, we built a pilot study to explore the behavior of membrane lung dead space as a possible quantifiable indicator of membrane lung efficiency and as a reliable predictor of ECMO failure.