The PaO2/FiO2 is Independently Associated with 28-Day Mortality in Patients with Sepsis: A retrospective analysis from MIMIC-IV database

Abstract

Abstract Objectives To clarify the relationship between the PaO2/FiO2 and 28-day mortality in patients with sepsis. Methods This was a retrospective cohort study regarding MIMIC- IV database. A total of 35,010 patients with sepsis were included in this database. PaO2/FiO2 was exposure variable, 28-day mortality was outcome variable. PaO2/FiO2 was log-transformed as LnPaO2/FiO2. Binary logistic regression was used to explore the independent effects of LnPaO2/FiO2 on 28-day mortality using non-adjusted and multivariate-adjusted models. A generalized additive model (GAM) and smoothed curve fitting were used to investigate the non-linear relationship between LnPaO2/FiO2 and 28-day mortality. A two-piecewise linear model was used to calculate the OR and 95% CI on either side of the inflection point. Results A total 19,233 cases were included in the final analysis. The relationship between LnPaO2/FiO2 and risk of 28-day death in sepsis patients was U-shape. The inflection point of LnPaO2/FiO2 was 5.32(95%CI:5.22–5.39), which indicated the inflection point of PaO2/FiO2 was 204.38mmHg (95%CI: 184.93mmHg − 219.20mmHg). On the left of inflection point, LnPaO2/FiO2 was negatively correlated with 28-day mortality(OR:0.38, 95%CI༚0.33, 0.44, p < 0.0001). On the right of inflection point, LnPaO2/FiO2 was positively correlated with 28-day mortality in patients with sepsis (OR:1.67,95%CI༚1.42, 1.96, p < 0.0001). Conclusions In patients with sepsis, either a high or low PaO2/FiO2 was associated with an increased risk of 28-day mortality. In the range of 184.93mmHg to 219.20 mmHg, PaO2/FiO2 was associated with a lower risk of 28-day death in patients with sepsis.