considerable uncertainty remains in the 2016-2020 retrospective dataset. Perhaps this "uncertainty" feature of the data should be highlighted. In our current practice, we continue to use centrifugal pumps in neonatal cases of venovenous ECMO. It would be helpful to know what the authors currently use in their practice, that is, have the results of the ELSO 2016-2021 study ( 1) altered what they do?Thus, taking all the above together we hope, like us, the ECMO community continues to be reflective about neonatal practice.