Participants, eligibility criteria and settings
The detailed study intervention and inclusion and exclusion criteria were published previously [Written informed consent was obtained from all study participants, and the study was conducted according to the guidelines of the Declaration of Helsinki. Data was obtained at the Bern University Hospital in Bern, Switzerland, as part of an investigation into a possible ventilatory effect of different flow rates of trans nasal oxygen delivery between March 2018 and December 2019.