We read with great interest Pavlov’s letter to the editor on oxygenation targets and optimization of mechanical ventilation (MV) during extracorporeal membrane oxygenation. Adding FiO₂ titration strategy would have been a good addition to the questionnaire and if we conduct a following survey we will certainly take this topic into account. In our survey, most centers said they had different MV strategies in venoarterial extracorporeal membrane oxygenation (VA-ECMO) compared to veno-venous (VV)-ECMO. Most participants indicated they did not use lung rest settings in this population. Of note, the questions in the survey concerned VA-ECMO patients without respiratory compromise.

The sixth edition of the ELSO Red Book contains only four pages on MV in adults with cardiac failure. They advise applying a lung protective MV with a noninjurious FiO₂ setting. They mention the challenge of targets for SaO₂ and PaO₂ depending on the cannula configuration and the competition between native and ECMO circulation.¹ The ELSO guideline for VA-ECMO in adult cardiac patients does not mention FiO₂ titration.²

A pragmatic approach during VA-ECMO involves measuring the oxygen saturation at the right radial artery, echocardiography for monitoring cardiac function, and, in selected patients, titration of the fraction of oxygen in the mixture via the air-oxygen blender to target postoxygenator PaO₂ of 150–300 mm Hg.³

We agree with Pavlov that all these methods are not suitable for precise measurements of coronary oxygenation. However, we believe that measuring the oxygen saturation at the right radial artery, combined with the postoxygenator blood gas analysis, gives us a sufficient indication of cerebral oxygen saturation.