Oxygen management in mechanically ventilated patients: A multicenter prospective observational study

To observe arterial oxygen in relation to fraction of inspired oxygen (F_IO₂) during mechanical ventilation (MV).

In this multicenter prospective observational study, we included adult patients required MV for >48h during the period from March to May 2015. We obtained F_IO₂, PaO₂ and SaO₂ from commencement of MV until the 7th day of MV in the ICU.

We included 454 patients from 28 ICUs in this study. The median APACHE II score was 22. Median values of F_IO₂, PaO₂ and SaO₂ were 0.40, 96mmHg and 98%. After day two, patients spent most of their time with a F_IO₂ between 0.3 and 0.49 with median PaO₂ of approximately 90mmHg and SaO₂ of 97%. PaO₂ was ≥100mmHg during 47.2% of the study period and was ≥130mmHg during 18.4% of the study period. F_IO₂ was more likely decreased when PaO₂ was ≥130mmHg or SaO₂ was ≥99% with a F_IO₂ of 0.5 or greater. When F_IO₂ was <0.5, however, F_IO₂ was less likely decreased regardless of the value of PaO₂ and SaO₂.

In our multicenter prospective study, we found that hyperoxemia was common and that hyperoxemia was not corrected.