Combination of positioning therapy and venovenous extracorporeal membrane oxygenation in ARDS patients.

Positioning therapy may improve lung recruitment and oxygenation and is part of the standard care in severe acute respiratory distress syndrome (ARDS). Venovenous extracorporeal membrane oxygenation (vvECMO) is a rescue strategy that may ensure sufficient gas exchange in ARDS patients failing conventional therapy. The aim of this case series was to describe the feasibility and pitfalls of combining positioning therapy and vvECMO in patients with severe ARDS. A retrospective cohort of nine patients is described. The patients received 20 (15-86) hours (median, 25(th) and 75(th) percentile) of positioning therapy while being treated with vvECMO. The initial PaO2/FiO2 index was 64 (51-67) mmHg and the arterial carbon dioxide tension was 60 (50-71) mmHg. Positioning therapy included 135 degrees prone, prone positioning and continuous lateral rotational therapy. During the first three days, the oxygenation index improved from 47 (41-47) to 12 (11-14) cmH2O/mmHg. The lung compliance improved from 20 (17-28) to 42 (27-43) ml/cmH2O. Complications related to positioning therapy were facial oedema (n=9); complications related to vvECMO were entrance of air (n=1) and pump failure (n=1). However, investigation of root causes revealed no association with the positioning therapy and had no documented effect on the outcome. The reported cases suggest that positioning therapy can be performed safely in ARDS patients treated with vvECMO, providing appropriate precautions are in place and a very experienced team is present.