[Impact of hyperoxia exposure on 28-day mortality and hospital-acquired infections in sepsis patients].

OBJECTIVE

To analyze the impact of hyperoxia exposure on 28-day mortality and hospital-acquired infections in sepsis patients.

METHODS

Clinical data from the Medical Information Mart for Intensive Care- IV (MIMIC- IV) database were retrospectively analyzed for sepsis patients who received oxygen therapy for more than 12 hours during their first intensive care unit (ICU) admission. Data includes demographics, sequential organ failure assessment (SOFA), acute physiology and chronic health evaluation II (APACHE II), vital signs, laboratory tests, treatment details (such as ventilation settings and medication use), and outcome variables. Patients were divided into three groups based on fraction of inspired oxygen (FiO2) levels: <0.60, 0.60-0.80, and >0.80. The FiO2 was used as the exposure variable, while 28-day mortality and hospital-acquired infections served as the outcome variables. Multivariate Logistic regression analysis was used to investigate the connections between independent variables and outcome variables. Kaplan-Meier survival curve was used to examine the 28-day cumulative survival rate of sepsis patients at various FiO2 levels.

RESULTS

Among 28 670 first-time ICU admissions in the MIMIC- IV database, 3 782 patients met the Sepsis-3 criteria. Among them, 1 681 patients received oxygen therapy for more than 12 hours, with 1 378 patients in the FiO2 < 0.60 group, 172 patients in the FiO2 0.60-0.80 group, and 131 patients in the FiO2 > 0.80 group. The 28-day mortality was 16.48% (277/1 681), and the rate of hospital-acquired infections was 24.51% (412/1 681). Compared with the FiO2 < 0.60 group, patients in both the FiO2 0.60-0.80 and FiO2 > 0.80 groups had higher SOFA scores, respiratory rates, heart rate, but lower arterial partial pressure of oxygen, and also more likely to require invasive mechanical ventilation, continuous renal replacement therapy (CRRT), and had a higher administration rate of epinephrine. Multivariate Logistic regression analysis showed that the CRRT [odds ratio (OR) = 1.391, 95% confidence interval (95%CI) was 1.000-1.935, P = 0.050] and FiO2 > 0.80 (OR = 1.476, 95%CI was 1.215-1.793, P < 0.001) were independent risk factors for 28-day death in sepsis patients. While invasive mechanical ventilation (OR = 2.098, 95%CI was 1.369-3.213, P = 0.001) and FiO2 > 0.80 (OR = 1.412, 95%CI was 1.173-1.698, P < 0.001) were independent predictors of hospital-acquired infection. Kaplan-Meier survival curve analysis showed that there was a statistically significant difference in 28-day cumulative survival rate among sepsis patients in different FiO2 groups (log-rank test, χ 2 = 21.626, P < 0.001). The higher the FiO2, the lower the 28-day cumulative survival rate of patients.

CONCLUSIONS

Among sepsis patients, higher FiO2 (> 0.80) is independently associated with an increased risk of 28-day mortality and hospital-acquired infection.