3 Citations (Scopus)


Background: The SpO2/FiO2 is a useful oxygenation parameter with prognostic capacity in patients with ARDS. We investigated the prognostic capacity of SpO2/FiO2 for mortality in patients with ARDS due to COVID–19. Methods: This was a post-hoc analysis of a national multicenter cohort study in invasively ventilated patients with ARDS due to COVID–19. The primary endpoint was 28–day mortality. Results: In 869 invasively ventilated patients, 28–day mortality was 30.1%. The SpO2/FiO2 on day 1 had no prognostic value. The SpO2/FiO2 on day 2 and day 3 had prognostic capacity for death, with the best cut-offs being 179 and 199, respectively. Both SpO2/FiO2 on day 2 (OR, 0.66 [95%–CI 0.46–0.96]) and on day 3 (OR, 0.70 [95%–CI 0.51–0.96]) were associated with 28–day mortality in a model corrected for age, pH, lactate levels and kidney dysfunction (AUROC 0.78 [0.76–0.79]). The measured PaO2/FiO2 and the PaO2/FiO2 calculated from SpO2/FiO2 were strongly correlated (Spearman's r = 0.79). Conclusions: In this cohort of patients with ARDS due to COVID–19, the SpO2/FiO2 on day 2 and day 3 are independently associated with and have prognostic capacity for 28–day mortality. The SpO2/FiO2 is a useful metric for risk stratification in invasively ventilated COVID–19 patients.
Original languageEnglish
Pages (from-to)31-37
Number of pages7
JournalJournal of critical care
Early online date3 Dec 2021
Publication statusPublished - 1 Apr 2022


  • Acute respiratory distress syndrome
  • COVID-19
  • Mechanical ventilation
  • Pulse oximetry
  • Resource limited settings
  • SpO /FiO
  • SpO/FiO
  • SpO2/FiO2

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