# The Comparative Impact of Liberal Versus Conservative Oxygenation in Critically Ill COVID-19 Patients: A Retrospective Study

## TL;DR

This study compared the effects of high and low oxygen levels in critically ill COVID-19 patients and found no significant difference in outcomes.

## Contribution

The study provides new evidence on the lack of impact of liberal versus conservative oxygenation strategies in COVID-19 patients.

## Key findings

- The low PaO2 group had higher SOFA scores at baseline and after 48 hours compared to the high PaO2 group.
- There was no significant difference in mortality rates between the high and low PaO2 groups.
- The change in SOFA score over 48 hours was not statistically significant between the two groups.

## Abstract

Objectives

Whether a higher or lower partial pressure of oxygen (PaO2) could impact outcomes in patients with coronavirus disease 2019 (COVID-19) remains a matter of debate. So, we planned this retrospective analysis to determine if a higher or lower partial pressure of oxygen in blood had any effect on outcomes in COVID-19 patients.

Material and method

The records of COVID-19 patients from the beginning of 2020 to the end of 2022 were scanned. Patients were sub-grouped into two groups based on the partial pressure of oxygen (PaO2) values on arterial blood gas (ABG), i.e., high PaO2 group, PaO2 value of 80-100 mm Hg, and low PaO2 group, PaO2 value of 60-80 mm Hg for the first 48 hours after the initiation of oxygenation and/or mechanical ventilation. The two groups were compared in terms of partial pressure of oxygen in arterial blood to the fraction of inspiratory oxygen (FiO2) concentration (P/F ratio), Sequential Organ Failure Assessment (SOFA) score at presentation and after 48 hours, and clinical outcomes, including mortality, time of mortality, extubation, acute kidney injury (AKI), and change in Glasgow Coma Scale (GCS).

Results

SOFA score was significantly higher in the low PaO2 group as compared to the high PaO2 group both at baseline (4.59 {1.79} versus 5.51 {1.15}; p-value: 0.005) and at 48 hours (3.06 {1.39} versus 5.11 {2.13}; p-value: 0.007). However, the change in SOFA score over 48 hours did not achieve statistical significance (-1.000 {0.97} versus 0.53 {2.34}; p-value: 0.257). Out of a total of 37 patients, 21 patients died in the high PaO2 group, while 18 patients died in the low PaO2 group.

Conclusion

Our study highlights that targeting either low or high arterial oxygen content while considering oxygen therapy for COVID-19 patients did not significantly alter the outcomes.