To observe arterial oxygen in relation to fraction of inspired oxygen (FIO2) during mechanical ventilation (MV).Materials and methods:
In this multicenter prospective observational study, we included adult patients required MV for >48 h during the period from March to May 2015. We obtained FIO2, PaO2 and SaO2 from commencement of MV until the 7th day of MV in the ICU.Results:
We included 454 patients from 28 ICUs in this study. The median APACHE II score was 22. Median values of FIO2, PaO2 and SaO2 were 0.40, 96 mm Hg and 98%. After day two, patients spent most of their time with a FIO2 between 0.3 and 0.49 with median PaO2 of approximately 90 mm Hg and SaO2 of 97%. PaO2 was ≥100 mm Hg during 47.2% of the study period and was ≥130 mm Hg during 18.4% of the study period. FIO2 was more likely decreased when PaO2 was ≥130 mm Hg or SaO2 was ≥99% with a FIO2 of 0.5 or greater. When FIO2 was <0.5, however, FIO2 was less likely decreased regardless of the value of PaO2 and SaO2.Conclusions:
In our multicenter prospective study, we found that hyperoxemia was common and that hyperoxemia was not corrected.