The use of the pulse oximetric saturation/fraction of inspired oxygen ratio for risk stratification of patients with severe sepsis and septic shock

Ary Serpa Neto, Sérgio O. Cardoso, David S.Y. Ong, Daniel C. Espósito, Victor G.M. Pereira, José A. Manetta, Arjen J.C. Slooter, Olaf L. Cremer

Research output: Contribution to journalArticleResearchpeer-review

15 Citations (Scopus)


Purpose: Our aims were to determine whether the pulse oximetric saturation/fraction of inspired oxygen (S/F) can be used for the early identification of patients with sepsis who are at increased risk for death and to compare the S/F ratio with the Pao2/fraction of inspired oxygen (P/F) ratio. Materials and Methods: This is a retrospective cohort study in 260 patients admitted to 2 tertiary mixed intensive care units (ICUs) with severe sepsis or septic shock. We studied the association between tertiles of S/F ratio and ICU mortality using Cox regression. Subsequently, we compared corresponding measurements of S/F ratio and P/F ratio upon ICU admission using Pearson correlation coefficient (r). Results: We observed an overall case fatality of 72 (28%) of 260. After adjustment for severity of the illness, the lowest tertile (S/F, <. 164) at ICU admission was associated with increased mortality (hazard ratio, 1.87 [95% confidence interval, 1.02-3.41]) comparing to the highest tertile (S/F, >. 236). The S/F ratio was correlated with P/F ratio (r = 0.48; P < .0001). Conclusion: A low S/F at ICU admission is associated with increased risk of death in patients with severe sepsis or septic shock.

Original languageEnglish
Pages (from-to)681-686
Number of pages6
JournalJournal of Critical Care
Issue number5
Publication statusPublished - Oct 2013
Externally publishedYes


  • Risk factor
  • Sepsis
  • Septic shock
  • SpO

Cite this