Impacts of a fraction of inspired oxygen adjustment protocol in COVID-19 patients under mechanical ventilation: A prospective cohort study.

OBJECTIVE

We examined weather a protocol for fraction of inspired oxygen (FiO) adjustment can reduce hyperoxemia and excess oxygen use in COVID-19 patients mechanically ventilated.

DESIGN

Prospective cohort study.

SETTING

Two intensive care units (ICUs) dedicated to COVID-19 patients in Brazil.

PATIENTS

Consecutive patients with COVID-19 mechanically ventilated.

INTERVENTIONS

One ICU followed a FiO adjustment protocol based on SpO (conservative-oxygen ICU) and the other, which did not follow the protocol, constituted the control ICU.

MAIN VARIABLES OF INTEREST

Prevalence of hyperoxemia (PaO>100mmHg) on day 1, sustained hyperoxemia (present on days 1 and 2), and excess oxygen use (FiO>0.6 in patients with hyperoxemia) were compared between the two ICUs.

RESULTS

Eighty two patients from the conservative-oxygen ICU and 145 from the control ICU were included. The conservative-oxygen ICU presented lower prevalence of hyperoxemia on day 1 (40.2% vs. 75.9%, p<0.001) and of sustained hyperoxemia (12.2% vs. 49.6%, p<0.001). Excess oxygen use was less frequent in the conservative-oxygen ICU on day 1 (18.3% vs. 52.4%, p<0.001). Being admitted in the control ICU was independently associated with hyperoxemia and excess oxygen use. Multivariable analyses found no independent relationship between day 1 hyperoxemia, sustained hyperoxemia, or excess FiO use and adverse clinical outcomes.

CONCLUSIONS

Following FiO protocol was associated with lower hyperoxemia and less excess oxygen use. Although those results were not associated with better clinical outcomes, adopting FiO protocol may be useful in a scenario of depleted oxygen resources, as was seen during the COVID-19 pandemic.